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SPIN EFFECTS IN UNPOLARIZED SIDIS Francesca Giordano SPIN 2012, Dubna, Russia 1

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Page 1: F Giordano: spin-dependent effects in spin-averaged DIS

SPIN EFFECTS IN UNPOLARIZED SIDIS

PSHP2010, Frascati18th-21st October 2010

Kaon Azimuthal cosine modulationsin SIDIS unpolarized cross section Francesca GiordanoRebecca Lamb

!"#$%&'()"# *(+,,&-."&( "#/!010!/233/-.*#(4&.(&%+ )2%*."5&6 ).2-2#(

*-/789:8!

!"#$%&'()%**%+%,-'*%**%+%,-'./01$&/&1$2

DIS 2009 Madrid, 26-30 April 2009

Monday, October 18, 2010

Francesca GiordanoSPIN 2012, Dubna, Russia

1

Page 2: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Collinear case

targetpolarization

beam polarization virtual photon

polarization

d3⇤dxdydz = �2

xyQ2

�1 + ⇥2

2x

�{A(y)FUU,T +B(y)FUU,L}

SEMI-INCLUSIVE DIS

2

Page 3: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

targetpolarization

beam polarization virtual photon

polarization

SEMI-INCLUSIVE DIS

2

Page 4: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

targetpolarization

beam polarization virtual photon

polarization

SEMI-INCLUSIVE DIS

Negative squared4-momentum transfer to the targetFractional energy of the virtual photonParton fractional momentumFractional energy transfer to the produced hadron

2

Page 5: F Giordano: spin-dependent effects in spin-averaged DIS

TRANSVERSE MOMENTUM DEPENDENT FUNCTIONS

DF

!FF

3

Page 6: F Giordano: spin-dependent effects in spin-averaged DIS

TRANSVERSE MOMENTUM DEPENDENT FUNCTIONS

DF

!FF

distribution functions

Chapter2

2.2. The interpretation of TMD

PDF probabilistic interpretation chiral properties

f q1 (x) chiral-even

gq1 (x) chiral-even

hq1 (x) chiral-odd

legendtransverse and longitudinal nucleon polarisation

transverse and longitudinal quark polarisation

Table 2.1.: Pictorial representation and chiral properties of the leading-twist PDF: The notation ofthe quark distribution functions uses the letters f ,g,h specifying the quark polarisationand a subscript indicating leading-twist (digit 1) or subleading-twist distributions (digit2). Unpolarised quarks are denoted as f , longitudinally (transversely) polarised quarks asg (h). The dependence of the PDF on the quark flavour is included as superscript q.

whereas the amplitude that defines the transversity distribution involves a helicity flip:

hq1 (x)⇥ℑ[A+�,�+]. (2.17)

The momentum distribution (figure 2.2) and the helicity distribution (figure 2.3) have been mea-sured accurately in a variety of experiments. The measurement of the transversity distribution ishampered by its chiral properties. In the infinite momentum frame, where quark masses can be ne-glected, helicity and chirality properties of quarks are identical. Thus, the transversity distribution isassociated with both a helicity and chirality flip and known as a chiral-odd function. Chiral symmetrycan be dynamically broken for quark distribution (or fragmentation) functions which are describedby non-perturbative QCD. But chirality is conserved for all perturbative QCD and electroweak pro-cesses such as inclusive measurements of deep-inelastic scattering. Hence, the transversity distribu-tion can only be studied in interactions involving another chiral-odd (distribution or fragmentation)function. One example is an analysis of the Collins mechanism which is sensitive to transversity inconjunction with a chiral-odd fragmentation function (section 2.3).Another consequence of the chiral properties is the simple scale-dependence of the transversity

distribution. A helicity flip of spin-1 gluons would require a change of the nucleons’ helicities by|Λ�Λ⇤| = 2. Thus, there is no analogon of transversity for gluons in a nucleon. Contrary to themomentum and helicity distributions, transversity does not mix with gluons under Q2-evolution, i.e.there is no sea-quark contribution and transversity decreases slowly towards zero with increasingQ2.

2.2. The interpretation of TMDLeading twist effects are associated with quark-quark correlations; quark-gluon correlations enter atsubleading twist. In section 2.1.3, the leading twist parametrisation of the nucleon structure is dis-cussed in terms of the momentum f q1 (x), helicity gq1 (x) and transversity h

q1 (x) distributions. Omit-

ting also here the weak scale dependence, the three parton distribution functions depend only on theBjorken scaling variable x, representing in the infinite momentum frame the longitudinal momentum

9

transverse longitudinalnucleon spin

parton spin

DY 2011, BNL - May 11th, 2011Gunar Schnell

TMDs - Probabilistic interpretation

4

f1 =

g1 =

h1 =

f�1T =

h�1 =

h�1T =

h�1L =

g1T =

parton with transverse or longitudinal spin

parton transverse momentum

nucleon with transverse or longitudinal spin

Proton goes out of the screen/ photon goes into the screen

[courtesy of A. Bacchetta]

Wednesday, May 11, 2011

parton transverse momentum3

Page 7: F Giordano: spin-dependent effects in spin-averaged DIS

TRANSVERSE MOMENTUM DEPENDENT FUNCTIONS

DF

!FF

distribution functions

fragmentation functions

Chapter2

2.2. The interpretation of TMD

PDF probabilistic interpretation chiral properties

f q1 (x) chiral-even

gq1 (x) chiral-even

hq1 (x) chiral-odd

legendtransverse and longitudinal nucleon polarisation

transverse and longitudinal quark polarisation

Table 2.1.: Pictorial representation and chiral properties of the leading-twist PDF: The notation ofthe quark distribution functions uses the letters f ,g,h specifying the quark polarisationand a subscript indicating leading-twist (digit 1) or subleading-twist distributions (digit2). Unpolarised quarks are denoted as f , longitudinally (transversely) polarised quarks asg (h). The dependence of the PDF on the quark flavour is included as superscript q.

whereas the amplitude that defines the transversity distribution involves a helicity flip:

hq1 (x)⇥ℑ[A+�,�+]. (2.17)

The momentum distribution (figure 2.2) and the helicity distribution (figure 2.3) have been mea-sured accurately in a variety of experiments. The measurement of the transversity distribution ishampered by its chiral properties. In the infinite momentum frame, where quark masses can be ne-glected, helicity and chirality properties of quarks are identical. Thus, the transversity distribution isassociated with both a helicity and chirality flip and known as a chiral-odd function. Chiral symmetrycan be dynamically broken for quark distribution (or fragmentation) functions which are describedby non-perturbative QCD. But chirality is conserved for all perturbative QCD and electroweak pro-cesses such as inclusive measurements of deep-inelastic scattering. Hence, the transversity distribu-tion can only be studied in interactions involving another chiral-odd (distribution or fragmentation)function. One example is an analysis of the Collins mechanism which is sensitive to transversity inconjunction with a chiral-odd fragmentation function (section 2.3).Another consequence of the chiral properties is the simple scale-dependence of the transversity

distribution. A helicity flip of spin-1 gluons would require a change of the nucleons’ helicities by|Λ�Λ⇤| = 2. Thus, there is no analogon of transversity for gluons in a nucleon. Contrary to themomentum and helicity distributions, transversity does not mix with gluons under Q2-evolution, i.e.there is no sea-quark contribution and transversity decreases slowly towards zero with increasingQ2.

2.2. The interpretation of TMDLeading twist effects are associated with quark-quark correlations; quark-gluon correlations enter atsubleading twist. In section 2.1.3, the leading twist parametrisation of the nucleon structure is dis-cussed in terms of the momentum f q1 (x), helicity gq1 (x) and transversity h

q1 (x) distributions. Omit-

ting also here the weak scale dependence, the three parton distribution functions depend only on theBjorken scaling variable x, representing in the infinite momentum frame the longitudinal momentum

9

transverse longitudinalnucleon spin

parton spin

DY 2011, BNL - May 11th, 2011Gunar Schnell

TMDs - Probabilistic interpretation

4

f1 =

g1 =

h1 =

f�1T =

h�1 =

h�1T =

h�1L =

g1T =

parton with transverse or longitudinal spin

parton transverse momentum

nucleon with transverse or longitudinal spin

Proton goes out of the screen/ photon goes into the screen

[courtesy of A. Bacchetta]

Wednesday, May 11, 2011

parton transverse momentum3

Page 8: F Giordano: spin-dependent effects in spin-averaged DIS

TRANSVERSE MOMENTUM DEPENDENT FUNCTIONS

DF

!FF

distribution functions

fragmentation functions

Chapter2

2.2. The interpretation of TMD

PDF probabilistic interpretation chiral properties

f q1 (x) chiral-even

gq1 (x) chiral-even

hq1 (x) chiral-odd

legendtransverse and longitudinal nucleon polarisation

transverse and longitudinal quark polarisation

Table 2.1.: Pictorial representation and chiral properties of the leading-twist PDF: The notation ofthe quark distribution functions uses the letters f ,g,h specifying the quark polarisationand a subscript indicating leading-twist (digit 1) or subleading-twist distributions (digit2). Unpolarised quarks are denoted as f , longitudinally (transversely) polarised quarks asg (h). The dependence of the PDF on the quark flavour is included as superscript q.

whereas the amplitude that defines the transversity distribution involves a helicity flip:

hq1 (x)⇥ℑ[A+�,�+]. (2.17)

The momentum distribution (figure 2.2) and the helicity distribution (figure 2.3) have been mea-sured accurately in a variety of experiments. The measurement of the transversity distribution ishampered by its chiral properties. In the infinite momentum frame, where quark masses can be ne-glected, helicity and chirality properties of quarks are identical. Thus, the transversity distribution isassociated with both a helicity and chirality flip and known as a chiral-odd function. Chiral symmetrycan be dynamically broken for quark distribution (or fragmentation) functions which are describedby non-perturbative QCD. But chirality is conserved for all perturbative QCD and electroweak pro-cesses such as inclusive measurements of deep-inelastic scattering. Hence, the transversity distribu-tion can only be studied in interactions involving another chiral-odd (distribution or fragmentation)function. One example is an analysis of the Collins mechanism which is sensitive to transversity inconjunction with a chiral-odd fragmentation function (section 2.3).Another consequence of the chiral properties is the simple scale-dependence of the transversity

distribution. A helicity flip of spin-1 gluons would require a change of the nucleons’ helicities by|Λ�Λ⇤| = 2. Thus, there is no analogon of transversity for gluons in a nucleon. Contrary to themomentum and helicity distributions, transversity does not mix with gluons under Q2-evolution, i.e.there is no sea-quark contribution and transversity decreases slowly towards zero with increasingQ2.

2.2. The interpretation of TMDLeading twist effects are associated with quark-quark correlations; quark-gluon correlations enter atsubleading twist. In section 2.1.3, the leading twist parametrisation of the nucleon structure is dis-cussed in terms of the momentum f q1 (x), helicity gq1 (x) and transversity h

q1 (x) distributions. Omit-

ting also here the weak scale dependence, the three parton distribution functions depend only on theBjorken scaling variable x, representing in the infinite momentum frame the longitudinal momentum

9

transverse longitudinalnucleon spin

parton spin

DY 2011, BNL - May 11th, 2011Gunar Schnell

TMDs - Probabilistic interpretation

4

f1 =

g1 =

h1 =

f�1T =

h�1 =

h�1T =

h�1L =

g1T =

parton with transverse or longitudinal spin

parton transverse momentum

nucleon with transverse or longitudinal spin

Proton goes out of the screen/ photon goes into the screen

[courtesy of A. Bacchetta]

Wednesday, May 11, 2011

parton transverse momentum3

Page 9: F Giordano: spin-dependent effects in spin-averaged DIS

TRANSVERSE MOMENTUM DEPENDENT FUNCTIONS

DF

!FF

distribution functions

fragmentation functions

Boer-Mulders DF

Chapter2

2.2. The interpretation of TMD

PDF probabilistic interpretation chiral properties

f q1 (x) chiral-even

gq1 (x) chiral-even

hq1 (x) chiral-odd

legendtransverse and longitudinal nucleon polarisation

transverse and longitudinal quark polarisation

Table 2.1.: Pictorial representation and chiral properties of the leading-twist PDF: The notation ofthe quark distribution functions uses the letters f ,g,h specifying the quark polarisationand a subscript indicating leading-twist (digit 1) or subleading-twist distributions (digit2). Unpolarised quarks are denoted as f , longitudinally (transversely) polarised quarks asg (h). The dependence of the PDF on the quark flavour is included as superscript q.

whereas the amplitude that defines the transversity distribution involves a helicity flip:

hq1 (x)⇥ℑ[A+�,�+]. (2.17)

The momentum distribution (figure 2.2) and the helicity distribution (figure 2.3) have been mea-sured accurately in a variety of experiments. The measurement of the transversity distribution ishampered by its chiral properties. In the infinite momentum frame, where quark masses can be ne-glected, helicity and chirality properties of quarks are identical. Thus, the transversity distribution isassociated with both a helicity and chirality flip and known as a chiral-odd function. Chiral symmetrycan be dynamically broken for quark distribution (or fragmentation) functions which are describedby non-perturbative QCD. But chirality is conserved for all perturbative QCD and electroweak pro-cesses such as inclusive measurements of deep-inelastic scattering. Hence, the transversity distribu-tion can only be studied in interactions involving another chiral-odd (distribution or fragmentation)function. One example is an analysis of the Collins mechanism which is sensitive to transversity inconjunction with a chiral-odd fragmentation function (section 2.3).Another consequence of the chiral properties is the simple scale-dependence of the transversity

distribution. A helicity flip of spin-1 gluons would require a change of the nucleons’ helicities by|Λ�Λ⇤| = 2. Thus, there is no analogon of transversity for gluons in a nucleon. Contrary to themomentum and helicity distributions, transversity does not mix with gluons under Q2-evolution, i.e.there is no sea-quark contribution and transversity decreases slowly towards zero with increasingQ2.

2.2. The interpretation of TMDLeading twist effects are associated with quark-quark correlations; quark-gluon correlations enter atsubleading twist. In section 2.1.3, the leading twist parametrisation of the nucleon structure is dis-cussed in terms of the momentum f q1 (x), helicity gq1 (x) and transversity h

q1 (x) distributions. Omit-

ting also here the weak scale dependence, the three parton distribution functions depend only on theBjorken scaling variable x, representing in the infinite momentum frame the longitudinal momentum

9

transverse longitudinalnucleon spin

parton spin

DY 2011, BNL - May 11th, 2011Gunar Schnell

TMDs - Probabilistic interpretation

4

f1 =

g1 =

h1 =

f�1T =

h�1 =

h�1T =

h�1L =

g1T =

parton with transverse or longitudinal spin

parton transverse momentum

nucleon with transverse or longitudinal spin

Proton goes out of the screen/ photon goes into the screen

[courtesy of A. Bacchetta]

Wednesday, May 11, 2011

parton transverse momentum3

Page 10: F Giordano: spin-dependent effects in spin-averaged DIS

TRANSVERSE MOMENTUM DEPENDENT FUNCTIONS

DF

!FF

distribution functions

fragmentation functions

Boer-Mulders DFCollins FF

Chapter2

2.2. The interpretation of TMD

PDF probabilistic interpretation chiral properties

f q1 (x) chiral-even

gq1 (x) chiral-even

hq1 (x) chiral-odd

legendtransverse and longitudinal nucleon polarisation

transverse and longitudinal quark polarisation

Table 2.1.: Pictorial representation and chiral properties of the leading-twist PDF: The notation ofthe quark distribution functions uses the letters f ,g,h specifying the quark polarisationand a subscript indicating leading-twist (digit 1) or subleading-twist distributions (digit2). Unpolarised quarks are denoted as f , longitudinally (transversely) polarised quarks asg (h). The dependence of the PDF on the quark flavour is included as superscript q.

whereas the amplitude that defines the transversity distribution involves a helicity flip:

hq1 (x)⇥ℑ[A+�,�+]. (2.17)

The momentum distribution (figure 2.2) and the helicity distribution (figure 2.3) have been mea-sured accurately in a variety of experiments. The measurement of the transversity distribution ishampered by its chiral properties. In the infinite momentum frame, where quark masses can be ne-glected, helicity and chirality properties of quarks are identical. Thus, the transversity distribution isassociated with both a helicity and chirality flip and known as a chiral-odd function. Chiral symmetrycan be dynamically broken for quark distribution (or fragmentation) functions which are describedby non-perturbative QCD. But chirality is conserved for all perturbative QCD and electroweak pro-cesses such as inclusive measurements of deep-inelastic scattering. Hence, the transversity distribu-tion can only be studied in interactions involving another chiral-odd (distribution or fragmentation)function. One example is an analysis of the Collins mechanism which is sensitive to transversity inconjunction with a chiral-odd fragmentation function (section 2.3).Another consequence of the chiral properties is the simple scale-dependence of the transversity

distribution. A helicity flip of spin-1 gluons would require a change of the nucleons’ helicities by|Λ�Λ⇤| = 2. Thus, there is no analogon of transversity for gluons in a nucleon. Contrary to themomentum and helicity distributions, transversity does not mix with gluons under Q2-evolution, i.e.there is no sea-quark contribution and transversity decreases slowly towards zero with increasingQ2.

2.2. The interpretation of TMDLeading twist effects are associated with quark-quark correlations; quark-gluon correlations enter atsubleading twist. In section 2.1.3, the leading twist parametrisation of the nucleon structure is dis-cussed in terms of the momentum f q1 (x), helicity gq1 (x) and transversity h

q1 (x) distributions. Omit-

ting also here the weak scale dependence, the three parton distribution functions depend only on theBjorken scaling variable x, representing in the infinite momentum frame the longitudinal momentum

9

transverse longitudinalnucleon spin

parton spin

DY 2011, BNL - May 11th, 2011Gunar Schnell

TMDs - Probabilistic interpretation

4

f1 =

g1 =

h1 =

f�1T =

h�1 =

h�1T =

h�1L =

g1T =

parton with transverse or longitudinal spin

parton transverse momentum

nucleon with transverse or longitudinal spin

Proton goes out of the screen/ photon goes into the screen

[courtesy of A. Bacchetta]

Wednesday, May 11, 2011

parton transverse momentum3

Page 11: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Chapter2

2.2. The interpretation of TMD

PDF probabilistic interpretation chiral properties

f q1 (x) chiral-even

gq1 (x) chiral-even

hq1 (x) chiral-odd

legendtransverse and longitudinal nucleon polarisation

transverse and longitudinal quark polarisation

Table 2.1.: Pictorial representation and chiral properties of the leading-twist PDF: The notation ofthe quark distribution functions uses the letters f ,g,h specifying the quark polarisationand a subscript indicating leading-twist (digit 1) or subleading-twist distributions (digit2). Unpolarised quarks are denoted as f , longitudinally (transversely) polarised quarks asg (h). The dependence of the PDF on the quark flavour is included as superscript q.

whereas the amplitude that defines the transversity distribution involves a helicity flip:

hq1 (x)⇥ℑ[A+�,�+]. (2.17)

The momentum distribution (figure 2.2) and the helicity distribution (figure 2.3) have been mea-sured accurately in a variety of experiments. The measurement of the transversity distribution ishampered by its chiral properties. In the infinite momentum frame, where quark masses can be ne-glected, helicity and chirality properties of quarks are identical. Thus, the transversity distribution isassociated with both a helicity and chirality flip and known as a chiral-odd function. Chiral symmetrycan be dynamically broken for quark distribution (or fragmentation) functions which are describedby non-perturbative QCD. But chirality is conserved for all perturbative QCD and electroweak pro-cesses such as inclusive measurements of deep-inelastic scattering. Hence, the transversity distribu-tion can only be studied in interactions involving another chiral-odd (distribution or fragmentation)function. One example is an analysis of the Collins mechanism which is sensitive to transversity inconjunction with a chiral-odd fragmentation function (section 2.3).Another consequence of the chiral properties is the simple scale-dependence of the transversity

distribution. A helicity flip of spin-1 gluons would require a change of the nucleons’ helicities by|Λ�Λ⇤| = 2. Thus, there is no analogon of transversity for gluons in a nucleon. Contrary to themomentum and helicity distributions, transversity does not mix with gluons under Q2-evolution, i.e.there is no sea-quark contribution and transversity decreases slowly towards zero with increasingQ2.

2.2. The interpretation of TMDLeading twist effects are associated with quark-quark correlations; quark-gluon correlations enter atsubleading twist. In section 2.1.3, the leading twist parametrisation of the nucleon structure is dis-cussed in terms of the momentum f q1 (x), helicity gq1 (x) and transversity h

q1 (x) distributions. Omit-

ting also here the weak scale dependence, the three parton distribution functions depend only on theBjorken scaling variable x, representing in the infinite momentum frame the longitudinal momentum

9

transverse longitudinalnucleon spin

parton spin

DY 2011, BNL - May 11th, 2011Gunar Schnell

TMDs - Probabilistic interpretation

4

f1 =

g1 =

h1 =

f�1T =

h�1 =

h�1T =

h�1L =

g1T =

parton with transverse or longitudinal spin

parton transverse momentum

nucleon with transverse or longitudinal spin

Proton goes out of the screen/ photon goes into the screen

[courtesy of A. Bacchetta]

Wednesday, May 11, 2011

parton transverse momentum

LEADING TWIST TERMS

implicit sum over quark flavors

distribution functions

fragmentation functions

4

Page 12: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

LEADING AND NEXT-TO-LEADING TWIST TERMS

implicit sum over quark flavors

distribution functions

Chapter2

2.2. The interpretation of TMD

PDF probabilistic interpretation chiral properties

f q1 (x) chiral-even

gq1 (x) chiral-even

hq1 (x) chiral-odd

legendtransverse and longitudinal nucleon polarisation

transverse and longitudinal quark polarisation

Table 2.1.: Pictorial representation and chiral properties of the leading-twist PDF: The notation ofthe quark distribution functions uses the letters f ,g,h specifying the quark polarisationand a subscript indicating leading-twist (digit 1) or subleading-twist distributions (digit2). Unpolarised quarks are denoted as f , longitudinally (transversely) polarised quarks asg (h). The dependence of the PDF on the quark flavour is included as superscript q.

whereas the amplitude that defines the transversity distribution involves a helicity flip:

hq1 (x)⇥ℑ[A+�,�+]. (2.17)

The momentum distribution (figure 2.2) and the helicity distribution (figure 2.3) have been mea-sured accurately in a variety of experiments. The measurement of the transversity distribution ishampered by its chiral properties. In the infinite momentum frame, where quark masses can be ne-glected, helicity and chirality properties of quarks are identical. Thus, the transversity distribution isassociated with both a helicity and chirality flip and known as a chiral-odd function. Chiral symmetrycan be dynamically broken for quark distribution (or fragmentation) functions which are describedby non-perturbative QCD. But chirality is conserved for all perturbative QCD and electroweak pro-cesses such as inclusive measurements of deep-inelastic scattering. Hence, the transversity distribu-tion can only be studied in interactions involving another chiral-odd (distribution or fragmentation)function. One example is an analysis of the Collins mechanism which is sensitive to transversity inconjunction with a chiral-odd fragmentation function (section 2.3).Another consequence of the chiral properties is the simple scale-dependence of the transversity

distribution. A helicity flip of spin-1 gluons would require a change of the nucleons’ helicities by|Λ�Λ⇤| = 2. Thus, there is no analogon of transversity for gluons in a nucleon. Contrary to themomentum and helicity distributions, transversity does not mix with gluons under Q2-evolution, i.e.there is no sea-quark contribution and transversity decreases slowly towards zero with increasingQ2.

2.2. The interpretation of TMDLeading twist effects are associated with quark-quark correlations; quark-gluon correlations enter atsubleading twist. In section 2.1.3, the leading twist parametrisation of the nucleon structure is dis-cussed in terms of the momentum f q1 (x), helicity gq1 (x) and transversity h

q1 (x) distributions. Omit-

ting also here the weak scale dependence, the three parton distribution functions depend only on theBjorken scaling variable x, representing in the infinite momentum frame the longitudinal momentum

9

transverse longitudinalnucleon spin

parton spin

DY 2011, BNL - May 11th, 2011Gunar Schnell

TMDs - Probabilistic interpretation

4

f1 =

g1 =

h1 =

f�1T =

h�1 =

h�1T =

h�1L =

g1T =

parton with transverse or longitudinal spin

parton transverse momentum

nucleon with transverse or longitudinal spin

Proton goes out of the screen/ photon goes into the screen

[courtesy of A. Bacchetta]

Wednesday, May 11, 2011

parton transverse momentum

fragmentation functions

5

Page 13: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

LEADING AND NEXT-TO-LEADING TWIST TERMS

implicit sum over quark flavors

distribution functions

Chapter2

2.2. The interpretation of TMD

PDF probabilistic interpretation chiral properties

f q1 (x) chiral-even

gq1 (x) chiral-even

hq1 (x) chiral-odd

legendtransverse and longitudinal nucleon polarisation

transverse and longitudinal quark polarisation

Table 2.1.: Pictorial representation and chiral properties of the leading-twist PDF: The notation ofthe quark distribution functions uses the letters f ,g,h specifying the quark polarisationand a subscript indicating leading-twist (digit 1) or subleading-twist distributions (digit2). Unpolarised quarks are denoted as f , longitudinally (transversely) polarised quarks asg (h). The dependence of the PDF on the quark flavour is included as superscript q.

whereas the amplitude that defines the transversity distribution involves a helicity flip:

hq1 (x)⇥ℑ[A+�,�+]. (2.17)

The momentum distribution (figure 2.2) and the helicity distribution (figure 2.3) have been mea-sured accurately in a variety of experiments. The measurement of the transversity distribution ishampered by its chiral properties. In the infinite momentum frame, where quark masses can be ne-glected, helicity and chirality properties of quarks are identical. Thus, the transversity distribution isassociated with both a helicity and chirality flip and known as a chiral-odd function. Chiral symmetrycan be dynamically broken for quark distribution (or fragmentation) functions which are describedby non-perturbative QCD. But chirality is conserved for all perturbative QCD and electroweak pro-cesses such as inclusive measurements of deep-inelastic scattering. Hence, the transversity distribu-tion can only be studied in interactions involving another chiral-odd (distribution or fragmentation)function. One example is an analysis of the Collins mechanism which is sensitive to transversity inconjunction with a chiral-odd fragmentation function (section 2.3).Another consequence of the chiral properties is the simple scale-dependence of the transversity

distribution. A helicity flip of spin-1 gluons would require a change of the nucleons’ helicities by|Λ�Λ⇤| = 2. Thus, there is no analogon of transversity for gluons in a nucleon. Contrary to themomentum and helicity distributions, transversity does not mix with gluons under Q2-evolution, i.e.there is no sea-quark contribution and transversity decreases slowly towards zero with increasingQ2.

2.2. The interpretation of TMDLeading twist effects are associated with quark-quark correlations; quark-gluon correlations enter atsubleading twist. In section 2.1.3, the leading twist parametrisation of the nucleon structure is dis-cussed in terms of the momentum f q1 (x), helicity gq1 (x) and transversity h

q1 (x) distributions. Omit-

ting also here the weak scale dependence, the three parton distribution functions depend only on theBjorken scaling variable x, representing in the infinite momentum frame the longitudinal momentum

9

transverse longitudinalnucleon spin

parton spin

DY 2011, BNL - May 11th, 2011Gunar Schnell

TMDs - Probabilistic interpretation

4

f1 =

g1 =

h1 =

f�1T =

h�1 =

h�1T =

h�1L =

g1T =

parton with transverse or longitudinal spin

parton transverse momentum

nucleon with transverse or longitudinal spin

Proton goes out of the screen/ photon goes into the screen

[courtesy of A. Bacchetta]

Wednesday, May 11, 2011

parton transverse momentum

fragmentation functions

5

Page 14: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

LEADING AND NEXT-TO-LEADING TWIST TERMS

implicit sum over quark flavorsinteraction dependent

terms neglected

distribution functions

Chapter2

2.2. The interpretation of TMD

PDF probabilistic interpretation chiral properties

f q1 (x) chiral-even

gq1 (x) chiral-even

hq1 (x) chiral-odd

legendtransverse and longitudinal nucleon polarisation

transverse and longitudinal quark polarisation

Table 2.1.: Pictorial representation and chiral properties of the leading-twist PDF: The notation ofthe quark distribution functions uses the letters f ,g,h specifying the quark polarisationand a subscript indicating leading-twist (digit 1) or subleading-twist distributions (digit2). Unpolarised quarks are denoted as f , longitudinally (transversely) polarised quarks asg (h). The dependence of the PDF on the quark flavour is included as superscript q.

whereas the amplitude that defines the transversity distribution involves a helicity flip:

hq1 (x)⇥ℑ[A+�,�+]. (2.17)

The momentum distribution (figure 2.2) and the helicity distribution (figure 2.3) have been mea-sured accurately in a variety of experiments. The measurement of the transversity distribution ishampered by its chiral properties. In the infinite momentum frame, where quark masses can be ne-glected, helicity and chirality properties of quarks are identical. Thus, the transversity distribution isassociated with both a helicity and chirality flip and known as a chiral-odd function. Chiral symmetrycan be dynamically broken for quark distribution (or fragmentation) functions which are describedby non-perturbative QCD. But chirality is conserved for all perturbative QCD and electroweak pro-cesses such as inclusive measurements of deep-inelastic scattering. Hence, the transversity distribu-tion can only be studied in interactions involving another chiral-odd (distribution or fragmentation)function. One example is an analysis of the Collins mechanism which is sensitive to transversity inconjunction with a chiral-odd fragmentation function (section 2.3).Another consequence of the chiral properties is the simple scale-dependence of the transversity

distribution. A helicity flip of spin-1 gluons would require a change of the nucleons’ helicities by|Λ�Λ⇤| = 2. Thus, there is no analogon of transversity for gluons in a nucleon. Contrary to themomentum and helicity distributions, transversity does not mix with gluons under Q2-evolution, i.e.there is no sea-quark contribution and transversity decreases slowly towards zero with increasingQ2.

2.2. The interpretation of TMDLeading twist effects are associated with quark-quark correlations; quark-gluon correlations enter atsubleading twist. In section 2.1.3, the leading twist parametrisation of the nucleon structure is dis-cussed in terms of the momentum f q1 (x), helicity gq1 (x) and transversity h

q1 (x) distributions. Omit-

ting also here the weak scale dependence, the three parton distribution functions depend only on theBjorken scaling variable x, representing in the infinite momentum frame the longitudinal momentum

9

transverse longitudinalnucleon spin

parton spin

DY 2011, BNL - May 11th, 2011Gunar Schnell

TMDs - Probabilistic interpretation

4

f1 =

g1 =

h1 =

f�1T =

h�1 =

h�1T =

h�1L =

g1T =

parton with transverse or longitudinal spin

parton transverse momentum

nucleon with transverse or longitudinal spin

Proton goes out of the screen/ photon goes into the screen

[courtesy of A. Bacchetta]

Wednesday, May 11, 2011

parton transverse momentum

fragmentation functions

5

Page 15: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

LEADING AND NEXT-TO-LEADING TWIST TERMS

implicit sum over quark flavorsinteraction dependent

terms neglected

+M2

Q2 C [ �2T

M2 f1D1 + ...]

distribution functions

Chapter2

2.2. The interpretation of TMD

PDF probabilistic interpretation chiral properties

f q1 (x) chiral-even

gq1 (x) chiral-even

hq1 (x) chiral-odd

legendtransverse and longitudinal nucleon polarisation

transverse and longitudinal quark polarisation

Table 2.1.: Pictorial representation and chiral properties of the leading-twist PDF: The notation ofthe quark distribution functions uses the letters f ,g,h specifying the quark polarisationand a subscript indicating leading-twist (digit 1) or subleading-twist distributions (digit2). Unpolarised quarks are denoted as f , longitudinally (transversely) polarised quarks asg (h). The dependence of the PDF on the quark flavour is included as superscript q.

whereas the amplitude that defines the transversity distribution involves a helicity flip:

hq1 (x)⇥ℑ[A+�,�+]. (2.17)

The momentum distribution (figure 2.2) and the helicity distribution (figure 2.3) have been mea-sured accurately in a variety of experiments. The measurement of the transversity distribution ishampered by its chiral properties. In the infinite momentum frame, where quark masses can be ne-glected, helicity and chirality properties of quarks are identical. Thus, the transversity distribution isassociated with both a helicity and chirality flip and known as a chiral-odd function. Chiral symmetrycan be dynamically broken for quark distribution (or fragmentation) functions which are describedby non-perturbative QCD. But chirality is conserved for all perturbative QCD and electroweak pro-cesses such as inclusive measurements of deep-inelastic scattering. Hence, the transversity distribu-tion can only be studied in interactions involving another chiral-odd (distribution or fragmentation)function. One example is an analysis of the Collins mechanism which is sensitive to transversity inconjunction with a chiral-odd fragmentation function (section 2.3).Another consequence of the chiral properties is the simple scale-dependence of the transversity

distribution. A helicity flip of spin-1 gluons would require a change of the nucleons’ helicities by|Λ�Λ⇤| = 2. Thus, there is no analogon of transversity for gluons in a nucleon. Contrary to themomentum and helicity distributions, transversity does not mix with gluons under Q2-evolution, i.e.there is no sea-quark contribution and transversity decreases slowly towards zero with increasingQ2.

2.2. The interpretation of TMDLeading twist effects are associated with quark-quark correlations; quark-gluon correlations enter atsubleading twist. In section 2.1.3, the leading twist parametrisation of the nucleon structure is dis-cussed in terms of the momentum f q1 (x), helicity gq1 (x) and transversity h

q1 (x) distributions. Omit-

ting also here the weak scale dependence, the three parton distribution functions depend only on theBjorken scaling variable x, representing in the infinite momentum frame the longitudinal momentum

9

transverse longitudinalnucleon spin

parton spin

DY 2011, BNL - May 11th, 2011Gunar Schnell

TMDs - Probabilistic interpretation

4

f1 =

g1 =

h1 =

f�1T =

h�1 =

h�1T =

h�1L =

g1T =

parton with transverse or longitudinal spin

parton transverse momentum

nucleon with transverse or longitudinal spin

Proton goes out of the screen/ photon goes into the screen

[courtesy of A. Bacchetta]

Wednesday, May 11, 2011

parton transverse momentum

fragmentation functions

5

Page 16: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

6

Page 17: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

correlations between quark transverse spin & transverse momentum

6

Page 18: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

correlations between quark transverse spin & transverse momentum

SPIN Effect!

6

Page 19: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

chiral odd chiral odd

chiral even!

}correlations between quark transverse spin &

transverse momentum

h?1 H?

1

chiral odd functions

SPIN Effect!

6

Page 20: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

correlations between quark transverse spin & transverse momentum

chiral odd functions

naive Time reversal odd

SPIN Effect!

6

Page 21: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

Final State Interactions

correlations between quark transverse spin & transverse momentum

chiral odd functions

naive Time reversal odd

SPIN Effect!

6

uFSI

u

Page 22: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

Final State Interactions

correlations between quark transverse spin & transverse momentum

chiral odd functions

naive Time reversal oddSpatial distortions due to

spin-orbit correlations

SPIN Effect!

6

uFSI

u

Page 23: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

Final State Interactions

correlations between quark transverse spin & transverse momentum

chiral odd functions

naive Time reversal oddSpatial distortions due to

spin-orbit correlations

Collins FF H1A(z,kT2) correlates transverse spin of fragmenting quark

and transverse momentum PhA of produced hadron h

““CollinsCollins--effect” effect”

h

h

q q

Æ left-right (azimuthal) asymmetry in the direction of the outgoing hadron

our observable: singleour observable: single--spin spin azimuthalazimuthal asymmetryasymmetry

Collins effect

SPIN Effect!

6

uFSI

u

Page 24: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

Final State Interactions

correlations between quark transverse spin & transverse momentum

Spatial distortions due to spin-orbit correlations

Collins FF H1A(z,kT2) correlates transverse spin of fragmenting quark

and transverse momentum PhA of produced hadron h

““CollinsCollins--effect” effect”

h

h

q q

Æ left-right (azimuthal) asymmetry in the direction of the outgoing hadron

our observable: singleour observable: single--spin spin azimuthalazimuthal asymmetryasymmetry

Collins effect

SPIN Effect!

access to Collins effect

6

uFSI

u

Page 25: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

correlations between quark transverse spin & transverse momentum

Cahn effect / C [f1D1]

Ph?

Ph?kT

kT

SPIN Effect!

access to Collins effect

7

Page 26: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

correlations between quark transverse spin & transverse momentum

Cahn effect / C [f1D1]

Ph?

Ph?kT

kT

kinematic effect generated by parton intrinsic transverse motion

SPIN Effect!

access to Collins effect

7

Page 27: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

correlations between quark transverse spin & transverse momentum

Cahn effect / C [f1D1]

Ph?

Ph?kT

kT

kinematic effect generated by parton intrinsic transverse motion

hqT i ! cos�q

h ! cos�Hh

SPIN Effect!

access to Collins effect

7

Page 28: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

BOER-MULDERS EFFECT/ C [�h?

1 H?1 ]Boer-Mulders effect

kTkT

Ph?

Ph? sT

sT

correlations between quark transverse spin & transverse momentum

Cahn effect / C [f1D1]

Ph?

Ph?kT

kT

kinematic effect generated by parton intrinsic transverse motion

access to parton transverse momenta

hqT i ! cos�q

h ! cos�Hh

SPIN Effect!

access to Collins effect

7

Page 29: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca GiordanoFrancesca Giordano

HERMES @ HERA

8

Page 30: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

DESY

Francesca Giordano

HERMES @ HERA

8

Page 31: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

DESY

Francesca Giordano

HERMES @ HERA

27.6 GeV (e+/e-) lepton beam off D/H target

8

Page 32: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

HERMES

CIPANP San Diego, CA May 29, 2009Rebecca Lamb

The HERMES Spectrometer

6

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9

Page 33: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

HERMES

CIPANP San Diego, CA May 29, 2009Rebecca Lamb

The HERMES Spectrometer

6

!

"

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!!

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RICH

RICH

DIPOLE

DIPOLE

9

Page 34: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

HERMES

CIPANP San Diego, CA May 29, 2009Rebecca Lamb

The HERMES Spectrometer

6

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"

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!!

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$

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RICH

RICH

DIPOLE

DIPOLE

9

Page 35: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

HERMES

CIPANP San Diego, CA May 29, 2009Rebecca Lamb

The HERMES Spectrometer

6

!

"

#

!!

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$

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RICH

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DIPOLE

tracking detectors: momentum resolution <2.5%

9

Page 36: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

HERMES

CIPANP San Diego, CA May 29, 2009Rebecca Lamb

The HERMES Spectrometer

6

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"

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RICH

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tracking detectors: momentum resolution <2.5%

9

Page 37: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

HERMES

CIPANP San Diego, CA May 29, 2009Rebecca Lamb

The HERMES Spectrometer

6

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!!

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$

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particle identification: lepton/hadron separation

RICH

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tracking detectors: momentum resolution <2.5%

9

Page 38: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

HERMES

CIPANP San Diego, CA May 29, 2009Rebecca Lamb

The HERMES Spectrometer

6

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tracking detectors: momentum resolution <2.5%

9

Page 39: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

ACCEPTANCE CORRECTIONw = (x, y, z, Ph?)

�0w[1 + 2hcos�hiw + 2hcos 2�hiw]

10

Page 40: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

ACCEPTANCE CORRECTIONw = (x, y, z, Ph?)

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

10

Page 41: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

ACCEPTANCE CORRECTIONw = (x, y, z, Ph?)

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

10

Page 42: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

ACCEPTANCE CORRECTIONw = (x, y, z, Ph?)

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

34

MC

RAD

MCMCMC

accLn !!=MC

0"RAD

EXP

accLn !!" )1(0 +=

CAHNn

#h

#h

#h

#h

#h

)()( #!#!RADacc

)2coscos1( ## BA ++= LnEXP

0"CAHNn

0" )1(UUFA+

Generated in 4⇡

!"!#"!#!$ dLn MC

RAD

MCMCMCMC

acc ),(),()(0=

),(),( "!#"!#

RADacc)2cos)(cos)(1( "!"! BA ++= LnEXP )(0 !$ !d

%

Inside acceptanceMC

MC simulation of spectrometers to correct for acceptance/QED radiation

10

Page 43: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

ACCEPTANCE CORRECTIONw = (x, y, z, Ph?)

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

34

MC

RAD

MCMCMC

accLn !!=MC

0"RAD

EXP

accLn !!" )1(0 +=

CAHNn

#h

#h

#h

#h

#h

)()( #!#!RADacc

)2coscos1( ## BA ++= LnEXP

0"CAHNn

0" )1(UUFA+

Generated in 4⇡

!"!#"!#!$ dLn MC

RAD

MCMCMCMC

acc ),(),()(0=

),(),( "!#"!#

RADacc)2cos)(cos)(1( "!"! BA ++= LnEXP )(0 !$ !d

%

Inside acceptanceMC

MC simulation of spectrometers to correct for acceptance/QED radiation

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

n =

ZL⇥0

w�accw,�h

�radw,�hdw

10

Page 44: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

ACCEPTANCE CORRECTIONw = (x, y, z, Ph?)

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

34

MC

RAD

MCMCMC

accLn !!=MC

0"RAD

EXP

accLn !!" )1(0 +=

CAHNn

#h

#h

#h

#h

#h

)()( #!#!RADacc

)2coscos1( ## BA ++= LnEXP

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0" )1(UUFA+

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MCMCMCMC

acc ),(),()(0=

),(),( "!#"!#

RADacc)2cos)(cos)(1( "!"! BA ++= LnEXP )(0 !$ !d

%

Inside acceptanceMC

MC simulation of spectrometers to correct for acceptance/QED radiation

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

n =

ZL⇥0

w�accw,�h

�radw,�hdw

10

Page 45: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

ACCEPTANCE CORRECTIONw = (x, y, z, Ph?)

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

34

MC

RAD

MCMCMC

accLn !!=MC

0"RAD

EXP

accLn !!" )1(0 +=

CAHNn

#h

#h

#h

#h

#h

)()( #!#!RADacc

)2coscos1( ## BA ++= LnEXP

0"CAHNn

0" )1(UUFA+

Generated in 4⇡

!"!#"!#!$ dLn MC

RAD

MCMCMCMC

acc ),(),()(0=

),(),( "!#"!#

RADacc)2cos)(cos)(1( "!"! BA ++= LnEXP )(0 !$ !d

%

Inside acceptanceMC

Not allowed!

MC simulation of spectrometers to correct for acceptance/QED radiation

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

n =

ZL⇥0

w�accw,�h

�radw,�hdw

10

Page 46: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

ACCEPTANCE CORRECTIONw = (x, y, z, Ph?)

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

34

MC

RAD

MCMCMC

accLn !!=MC

0"RAD

EXP

accLn !!" )1(0 +=

CAHNn

#h

#h

#h

#h

#h

)()( #!#!RADacc

)2coscos1( ## BA ++= LnEXP

0"CAHNn

0" )1(UUFA+

Generated in 4⇡

!"!#"!#!$ dLn MC

RAD

MCMCMCMC

acc ),(),()(0=

),(),( "!#"!#

RADacc)2cos)(cos)(1( "!"! BA ++= LnEXP )(0 !$ !d

%

Inside acceptanceMC

Not allowed!

MC simulation of spectrometers to correct for acceptance/QED radiation

only if fully differential ratio (4D binning)and only in the limit of infinitely small bins

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

n =

ZL⇥0

w�accw,�h

�radw,�hdw

10

Page 47: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

w = (x, y, z, Ph?)

(w)4-dimensional

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Variable Bin limitsBin limitsBin limitsBin limitsBin limitsBin limitsBin limits #x 0.023 0.042 0.078 0.145 0.27 0.6 5

y 0.2 0.3 0.45 0.6 0.7 0.85 5

z 0.2 0.3 0.4 0.5 0.6 0.75 1 6

0.05 0.2 0.35 0.5 0.7 1 1.3 6Ph?

unfolding

ACCEPTANCE CORRECTION

11

Page 48: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

w = (x, y, z, Ph?)

(w)4-dimensional

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

nborn

= S�1[n�B0]

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Variable Bin limitsBin limitsBin limitsBin limitsBin limitsBin limitsBin limits #x 0.023 0.042 0.078 0.145 0.27 0.6 5

y 0.2 0.3 0.45 0.6 0.7 0.85 5

z 0.2 0.3 0.4 0.5 0.6 0.75 1 6

0.05 0.2 0.35 0.5 0.7 1 1.3 6Ph?

unfolding

ACCEPTANCE CORRECTION

11

Page 49: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

w = (x, y, z, Ph?)

(w)4-dimensional

describes the acceptance & smearing between adjacent bins

events smeared in the sample from outside the acceptance

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

nborn

= S�1[n�B0]

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Variable Bin limitsBin limitsBin limitsBin limitsBin limitsBin limitsBin limits #x 0.023 0.042 0.078 0.145 0.27 0.6 5

y 0.2 0.3 0.45 0.6 0.7 0.85 5

z 0.2 0.3 0.4 0.5 0.6 0.75 1 6

0.05 0.2 0.35 0.5 0.7 1 1.3 6Ph?

unfolding

ACCEPTANCE CORRECTION

11

Page 50: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

w = (x, y, z, Ph?)

(w)4-dimensional

describes the acceptance & smearing between adjacent bins

events smeared in the sample from outside the acceptance

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

A(1 +B cos�h + C cos 2�h)

nborn

= S�1[n�B0]

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Variable Bin limitsBin limitsBin limitsBin limitsBin limitsBin limitsBin limits #x 0.023 0.042 0.078 0.145 0.27 0.6 5

y 0.2 0.3 0.45 0.6 0.7 0.85 5

z 0.2 0.3 0.4 0.5 0.6 0.75 1 6

0.05 0.2 0.35 0.5 0.7 1 1.3 6Ph?

unfolding

ACCEPTANCE CORRECTION

11

Page 51: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Variable Bin limitsBin limitsBin limitsBin limitsBin limitsBin limitsBin limits #x 0.023 0.042 0.078 0.145 0.27 0.6 5

y 0.2 0.3 0.45 0.6 0.7 0.85 5

z 0.2 0.3 0.4 0.5 0.6 0.75 1 6

0.05 0.2 0.35 0.5 0.7 1 1.3 6Ph?

PION FIT & PROJECTIONw = (x, y, z, Ph?)

(w)4-dimensional

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

A(1 +B cos�h + C cos 2�h)

unfolding

z

xy

Ph?

12

Page 52: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Variable Bin limitsBin limitsBin limitsBin limitsBin limitsBin limitsBin limits #x 0.023 0.042 0.078 0.145 0.27 0.6 5

y 0.2 0.3 0.45 0.6 0.7 0.85 5

z 0.2 0.3 0.4 0.5 0.6 0.75 1 6

0.05 0.2 0.35 0.5 0.7 1 1.3 6Ph?

0.023 0.042 0.078 0.145 0.27

0.3 0.45 0.6 0.7 0.85

0.2 0.3 0.4 0.5 0.6 0.750.05 0.2 0.35 0.5 0.7 1

PION FIT & PROJECTIONw = (x, y, z, Ph?)

(w)4-dimensional

n =

ZL⇥0

w[1 + 2hcos⇤hiw + 2hcos 2⇤hiw]�accw,�h�radw,�h

dw

A(1 +B cos�h + C cos 2�h)

unfolding

z

xy

Ph?

12

Page 53: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Boer-Mulders

Cahn

COS2 : PIONS�Final! / C [�h?

1 H?1

+2T

Q2f1D1 + ....]

13

arXiv:1204.4161

Page 54: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Cahn expected flavor blind

Boer-Mulders

Cahn

COS2 : PIONS�Final! / C [�h?

1 H?1

+2T

Q2f1D1 + ....]

13

arXiv:1204.4161

Page 55: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Cahn expected flavor blind

different / amplitudes Boer-Mulders effect

⇡+⇡�

Boer-Mulders

Cahn

COS2 : PIONS�Final! / C [�h?

1 H?1

+2T

Q2f1D1 + ....]

13

arXiv:1204.4161

Page 56: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Cahn expected flavor blind

different / amplitudes Boer-Mulders effect

⇡+⇡�

Boer-Mulders

Cahn

COS2 : PIONS�Final! / C [�h?

1 H?1

+2T

Q2f1D1 + ....]

SPIN Effect!13

arXiv:1204.4161

Page 57: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Cahn expected flavor blind

different / amplitudes Boer-Mulders effect

⇡+⇡�

Boer-Mulders

Cahn

Gamberg, GoldsteinPhys. Rev. D77:094016, 2008

COS2 : PIONS�Final! / C [�h?

1 H?1

+2T

Q2f1D1 + ....]

SPIN Effect!13

arXiv:1204.4161

Page 58: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Cahn expected flavor blind

different / amplitudes Boer-Mulders effect

⇡+⇡�

Boer-Mulders

Cahn

Zhang et alPhys. Rev. D78:034035, 2008

Gamberg, GoldsteinPhys. Rev. D77:094016, 2008

COS2 : PIONS�Final! / C [�h?

1 H?1

+2T

Q2f1D1 + ....]

SPIN Effect!13

arXiv:1204.4161

Page 59: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Cahn expected flavor blind

different / amplitudes Boer-Mulders effect

⇡+⇡�

Boer-Mulders

Cahn

Barone et alPhys. Rev. D78:045022, 2008

Zhang et alPhys. Rev. D78:034035, 2008

Gamberg, GoldsteinPhys. Rev. D77:094016, 2008

COS2 : PIONS�Final! / C [�h?

1 H?1

+2T

Q2f1D1 + ....]

SPIN Effect!13

arXiv:1204.4161

Page 60: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Cahn expected flavor blind

different / amplitudes Boer-Mulders effect

⇡+⇡�

Boer-Mulders

Cahn

COS2 : PIONS�Final! / C [�h?

1 H?1

+2T

Q2f1D1 + ....]

Hydrogen vs Deuterium

SPIN Effect!14

arXiv:1204.4161

Page 61: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Cahn expected flavor blind

different / amplitudes Boer-Mulders effect

⇡+⇡�

Boer-Mulders

Cahn

COS2 : PIONS�Final! / C [�h?

1 H?1

+2T

Q2f1D1 + ....]

h?,u1 ⇡ h?,d

1

Hydrogen vs Deuterium

SPIN Effect!14

arXiv:1204.4161

Page 62: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Cahn expected flavor blind

different / amplitudes Boer-Mulders effect

⇡+⇡�

COS : PIONS�Final!/ 2M

Q C [�h?1 H

?1

�f1D1 + ....]

15

arXiv:1204.4161

Page 63: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Cahn

Boer-Mulders

Cahn expected flavor blind

different / amplitudes Boer-Mulders effect

⇡+⇡�

COS : PIONS�Final!/ 2M

Q C [�h?1 H

?1

�f1D1 + ....]

15

arXiv:1204.4161

Page 64: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Cahn

/01&"#2'3" 456785988:.#;88<=>?"#/01&"#@" $A67A5A.#;885

!"

x

-110

UU

!)h"

co

s(

#2

-0.2

-0.1

0

0.1$%+%

y

0.4 0.6 0.8

-0.2

-0.1

0

0.1 X% e &e p

z 0.4 0.6

-0.2

-0.1

0

0.1

[GeV]'h

P

0.2 0.4 0.6 0.8 1

-0.2

-0.1

0

0.1 HERMES preliminary

#$%"& '$()*+,-$. [ ]...2

1111

cos +$$( '' DfHhQ

MF h

UU C"

!"#$%&'()*%+#', -(".#/01&"#2'3" 456785988:.#;88<=>?"#/01&"#@" $A67A5A.#;885

F cos�h

UU / C [h?1

H?1

�f1

D1

+....]F cos�h

UU / C [h?1

H?1

�f1

D1

+....]

Cahn only

Too large!

x

-110

UU

!)h"

co

s(

#2

-0.2

-0.1

0

0.1$%+%

y

0.4 0.6 0.8

-0.2

-0.1

0

0.1 X% e &e p

z 0.4 0.6

-0.2

-0.1

0

0.1

[GeV]'h

P

0.2 0.4 0.6 0.8 1

-0.2

-0.1

0

0.1 HERMES preliminary

" [ ]...2

1111

cos +$$( '' DfHhQ

MF h

UU C"

Boer-Mulders

Cahn expected flavor blind

different / amplitudes Boer-Mulders effect

⇡+⇡�

COS : PIONS�Final!/ 2M

Q C [�h?1 H

?1

�f1D1 + ....]

15

arXiv:1204.4161

Page 65: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Variable Bin limitsBin limitsBin limitsBin limitsBin limitsBin limitsBin limits #x 0.023 0.042 0.078 0.145 0.27 0.6 5

y 0.2 0.3 0.45 0.6 0.7 0.85 5

z 0.2 0.3 0.4 0.5 0.6 0.75 1 6

0.05 0.2 0.35 0.5 0.7 1 1.3 6Ph?

KAON FIT & PROJECTION

(w)4-dimensional

A(1 +B cos�h + C cos 2�h)

unfolding

z

xy

Ph?

16

Page 66: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Binning900 kinematic bins x 12 -bins

Variable Bin limitsBin limitsBin limitsBin limitsBin limitsBin limitsBin limits #x 0.023 0.042 0.078 0.145 0.27 0.6 5

y 0.2 0.3 0.45 0.6 0.7 0.85 5

z 0.2 0.3 0.4 0.5 0.6 0.75 1 6

0.05 0.2 0.35 0.5 0.7 1 1.3 6Ph?

KAON FIT & PROJECTION

0.042 0.078 0.145 0.27

0.3 0.45 0.6 0.7

0.3 0.4 0.5 0.6

0.2 0.35 0.5 0.7

(w)4-dimensional

A(1 +B cos�h + C cos 2�h)

unfolding

z

xy

Ph?

16

Page 67: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca GiordanoFrancesca Giordano

COS2 KAONS & PIONS�Final! / C [�h?

1 H?1

+2T

Q2f1D1 + ....]

17

arXiv:1204.4161

Page 68: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca GiordanoFrancesca Giordano

COS2 KAONS & PIONS�Final!

Boer-Mulders

Cahn

/ C [�h?1 H

?1

+2T

Q2f1D1 + ....]

17

arXiv:1204.4161

Page 69: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca GiordanoFrancesca Giordano

COS2 KAONS & PIONS�Final!

Boer-Mulders

Cahn

/ C [�h?1 H

?1

+2T

Q2f1D1 + ....]

No predictions for Kaons!

17

arXiv:1204.4161

Page 70: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca GiordanoFrancesca Giordano

COS2 KAONS & PIONS�Final!

Boer-Mulders

Cahn

/ C [�h?1 H

?1

+2T

Q2f1D1 + ....]

No predictions for Kaons! Favored dominance for & .

same signK+ ⇡+ ?

17

arXiv:1204.4161

Page 71: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca GiordanoFrancesca Giordano

COS2 KAONS & PIONS�Final!

Boer-Mulders

Cahn

/ C [�h?1 H

?1

+2T

Q2f1D1 + ....]

No predictions for Kaons! Favored dominance for & .

same signK+ ⇡+ ?

fully sea object!both favored&unfavored fragmentation

K�

17

arXiv:1204.4161

Page 72: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca GiordanoFrancesca Giordano

COS2 KAONS & PIONS�Final!

Boer-Mulders

Cahn

/ C [�h?1 H

?1

+2T

Q2f1D1 + ....]

No predictions for Kaons! Favored dominance for & .

same signK+ ⇡+ ?

fully sea object!both favored&unfavored fragmentation

K�

Non trivial!17

arXiv:1204.4161

Page 73: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca GiordanoFrancesca Giordano

COS2 KAONS & PIONS�Final!

Boer-Mulders

Cahn

/ C [�h?1 H

?1

+2T

Q2f1D1 + ....]

No predictions for Kaons! Favored dominance for & .

same signK+ ⇡+ ?

fully sea object!both favored&unfavored fragmentation

K�

Non trivial!

Collins FF for kaons soon from Belle

17

arXiv:1204.4161

Page 74: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

COS KAONS & PIONS�Final!

No predictions for Kaons!Similar trends for Pion-Kaon

/ 2MQ C [�h?

1 H?1

�f1D1 + ....]

18

arXiv:1204.4161

Page 75: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

COS KAONS & PIONS�Final!

No predictions for Kaons!Similar trends for Pion-Kaon ?

Cahn

Boer-Mulders

/ 2MQ C [�h?

1 H?1

�f1D1 + ....]

18

arXiv:1204.4161

Page 76: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

MULTI-D RESULTShttp://durpdg.dur.ac.uk

First 6 bins

19

Page 77: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

MULTI-D RESULTShttp://durpdg.dur.ac.uk

First 6 bins

1st x bin

20

Page 78: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

MULTI-D RESULTShttp://durpdg.dur.ac.uk

First 6 bins

1st x bin2nd x bin

20

Page 79: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

MULTI-D RESULTShttp://durpdg.dur.ac.uk

First 6 bins

1st x bin2nd x bin

3rd x bin

20

Page 80: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

MULTI-D RESULTShttp://durpdg.dur.ac.uk

First 6 bins

1st x bin2nd x bin

3rd x bin 4th x bin

20

Page 81: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

MULTI-D RESULTShttp://durpdg.dur.ac.uk

First 6 bins

1st x bin2nd x bin

3rd x bin 4th x bin 5th x bin

20

Page 82: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

MULTI-D RESULTShttp://durpdg.dur.ac.uk

First 6 bins

1st x bin2nd x bin

3rd x bin 4th x bin 5th x bin

HYDROGEN, .⇡+

DEUTERIUM, .⇡+

20

Page 83: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

MULTI-D RESULTShttp://durpdg.dur.ac.uk

First 6 bins

1st x bin2nd x bin

3rd x bin 4th x bin 5th x bin

HYDROGEN, .⇡+

HYDROGEN, .⇡�DEUTERIUM, .

⇡+DEUTERIUM, .⇡�

HYDROGEN, .K�HYDROGEN, .K+

DEUTERIUM, .K�DEUTERIUM, .K+

HYDROGEN, .HYDROGEN, .

DEUTERIUM, .DEUTERIUM, .

h+

h+h�

h�

20

Page 84: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

MULTI-D RESULTShttp://durpdg.dur.ac.uk

First 6 bins

1st x bin2nd x bin

3rd x bin 4th x bin 5th x bin

HYDROGEN, .⇡+

HYDROGEN, .⇡�DEUTERIUM, .

⇡+DEUTERIUM, .⇡�

HYDROGEN, .K�HYDROGEN, .K+

DEUTERIUM, .K�DEUTERIUM, .K+

HYDROGEN, .HYDROGEN, .

DEUTERIUM, .DEUTERIUM, .

THERE’S AN EASIER WAY!

h+

h+h�

h�

20

Page 85: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

A USEFUL TOOLhttp://www-hermes.desy.de/cosnphi/

New!

21

Page 86: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Variable Bin limitsBin limitsBin limitsBin limitsBin limitsBin limitsBin limits #

x 0.02 0.04 0.08 0.15 0.27 0.6 5

y 0.2 0.3 0.45 0.6 0.7 0.85 5

z 0.2 0.3 0.4 0.5 0.6 0.75 1 6

0.05 0.2 0.35 0.5 0.7 1 1 6Ph?

A USEFUL TOOL

New!

z

xy

Ph?

22

Page 87: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Variable Bin limitsBin limitsBin limitsBin limitsBin limitsBin limitsBin limits #

x 0.02 0.04 0.08 0.15 0.27 0.6 5

y 0.2 0.3 0.45 0.6 0.7 0.85 5

z 0.2 0.3 0.4 0.5 0.6 0.75 1 6

0.05 0.2 0.35 0.5 0.7 1 1 6Ph?

A USEFUL TOOL

New!

z

xy

Ph?

22

Page 88: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Binning900 kinematic bins x 12 - bins

Variable Bin limitsBin limitsBin limitsBin limitsBin limitsBin limitsBin limits #

x 0.02 0.04 0.08 0.15 0.27 0.6 5

y 0.2 0.3 0.45 0.6 0.7 0.85 5

z 0.2 0.3 0.4 0.5 0.6 0.75 1 6

0.05 0.2 0.35 0.5 0.7 1 1 6Ph?

A USEFUL TOOL

New!

z

xy

Ph?

22

Page 89: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

A USEFUL TOOL

New!23

Page 90: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

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Page 91: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

UU

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Page 92: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

PIONS: MORE PROJECTIONSFull z-dependence

24

Page 93: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

PIONS: MORE PROJECTIONSFull z-dependence

24

Page 94: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

PIONS: MORE PROJECTIONSFull z-dependence Full -dependencePh?

24

Page 95: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

KAONS: MORE PROJECTIONSLarger z-dependence Larger -dependencePh?

25

Page 96: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

KAONS: MORE PROJECTIONSLarger z-dependence Larger -dependencePh?

25

Page 97: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

SUMMARYTo date provides the most complete data set available for Boer-Mulders and Cahn effects!

DIS 2009 Madrid, 26-30 April 2009

26

Page 98: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Different behavior for with respect to pions:large signals and same sign for modulation: indication of same sign for favored/unfavored strange Collins fragmentation functions?

K+/K�

cos 2�h

SUMMARYTo date provides the most complete data set available for Boer-Mulders and Cahn effects!

DIS 2009 Madrid, 26-30 April 2009

26

Page 99: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Different behavior for with respect to pions:large signals and same sign for modulation: indication of same sign for favored/unfavored strange Collins fragmentation functions?

K+/K�

cos 2�h

Differences between :evidence of a non-zero Boer-Mulders function: confirms opposite sign for favored and unfavored pion Collins fragmentation functions

�+/��

SUMMARYTo date provides the most complete data set available for Boer-Mulders and Cahn effects!

DIS 2009 Madrid, 26-30 April 2009

26

Page 100: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Different behavior for with respect to pions:large signals and same sign for modulation: indication of same sign for favored/unfavored strange Collins fragmentation functions?

K+/K�

cos 2�h

Differences between :evidence of a non-zero Boer-Mulders function: confirms opposite sign for favored and unfavored pion Collins fragmentation functions

�+/��

Similar results for deuterium & hydrogen data suggest a Boer-Mulders function with same sign for u and d quark

SUMMARYTo date provides the most complete data set available for Boer-Mulders and Cahn effects!

DIS 2009 Madrid, 26-30 April 2009

26

Page 101: F Giordano: spin-dependent effects in spin-averaged DIS

Francesca Giordano

Different behavior for with respect to pions:large signals and same sign for modulation: indication of same sign for favored/unfavored strange Collins fragmentation functions?

K+/K�

cos 2�h

Differences between :evidence of a non-zero Boer-Mulders function: confirms opposite sign for favored and unfavored pion Collins fragmentation functions

�+/��

Thank you!Similar results for deuterium & hydrogen data suggest a Boer-Mulders function with same sign for u and d quark

SUMMARYTo date provides the most complete data set available for Boer-Mulders and Cahn effects!

DIS 2009 Madrid, 26-30 April 2009

26