a. drutskoy, itep, moscow recent results from belle qfthep’ 2010, golitsyno, moscow, russia,...

A. Drutskoy, ITEP, Moscow

Recent results from Belle

QFTHEP’ 2010, Golitsyno, Moscow, Russia, September 8-15, 2010

Mt.Tsukuba:Nyotai-san 877m,Nantai-san 871m

QFTHEP 2010, Recent results from Belle Golitsyno, Moscow, Russia, September 8 - 15 A. Drutskoy

Belle detector

e+ source

cavity

Belle

3.5 GeV e + 8 GeV e

-

Belle detector and KEKB collider

Belle is general purpose detector with high efficiencyand accuracy charged track and photon reconstruction,good particle identification and precise vertex resolution.

KEKB is asymmetricenergy e+e- collider

2QFTHEP 2010, Recent results from Belle Golitsyno, Moscow, Russia, September 8 - 15 A. Drutskoy

http://jp.f35.mail.yahoo.co.jp/ym/ShowLetter/ringanimation2M.gif?box=Inbox&MsgId=2406_9445966_98224_1696_384623_0_1738_499387_3403004772&bodyPart=1.4&filename=ringanimation2M.gif&tnef=&YY=43275&order=down&sort=date&pos=0&view=a&head=b

~7.7 x10 8 (S)

~9 x10 8

_

~6.4 x10 6 *s *

s (5S)_

Integrated luminosity collected by Belle

QFTHEP 2010, Recent results from Belle Golitsyno, Moscow, Russia, September 8 - 15 A. Drutskoy 3

Theories confirmed in B factories with high precision

1. Standard Model elements: quarks, leptons, photon, gluons, Z boson, W± bosons. No effects beyond Standard Model have been observed with >5 in particle physics.

2. Hadrons have fixed combinations of valence quarks: quark-antiquark pairs, or three quarks.

GOAL now: find effects contradicting to 1 or 2


How to search for BSM and exotics in B factories

1. Test unitarity of CKM matrix

It’s very smart and subtle method. Many BSM contributions will destroy unitarity. However it’s not easy to make predictions and conclusions.

2. Compare branching fractions and asymmetries of B, D, and decays obtained experimentally and predicted theoretically within SM. If Bf is unobservably small in SM => just search for such forbidden decays.

Look for hadrons with exotic masses, quantum numbers, decay rates anddecay final states.

Search for BSM:

Search for exotic hadrons:


CPV in B0 mixing and decays

t (decay time)[ps]

B0

B0 fcpfcpB0

B0

A

A

=mixing Decay: A

_A

1

2

3

Vtd Vtb

Vcd Vcb

Vud Vub*

*

*

f [S sin(md t ) + A cos(md

t )]

B0

B0_

sin 21

Pro

b.

ACP

S = sin

21


sin 2φ1 ≠ sin 2φ1eff

_

d

b_ c

csd

_wB0

J/ψ

K0 d

b_ _

sssd

_gtB0

K0

φ, f0

wb ccs tree

_b sqq penguin

_

S = sin2φ1, A ≈ 0 S = sin2φ1eff, A ≈ 0

In case of extra CP phasefrom NP in penguin loop

_

CP violation measurement in B0 K+ K–

KS0

Physics motivation for CP violation measurement in

b sqq transition


BSM contributions in b s penguin loop

SM Charged Higgs Chargino+squark 4-generation

Simplest BSM processes which could contribute in b->s loop



KS0

Unfortunately 4 solutions were obtained for phases and amplitudes of signals.These 4 solutions are consistent with each other within statistical errors.First solution (preferable) was used to measure CP violating parameters.

B 0 KS

0K +K

– signal => 1176±5Background Continuum ~ 47%

Other B decays ~3%Significant part of signal K+K-KS

0 goes via intermediate -> K+ K- and f0->

K+K-

657 x 106 BB pairs at (4S)

KS0

f0(980)KS0

Dalitz-plot

s+ = M 2(K+KS

0)

s – =

M 2(K

–K

S0)


Belle preliminary, arXiv:1007.3848

fS1

eff = (31.3 ± 9.0 ± 3.4 ± 4.0)0 fS1

eff = (31.3 ± 9.0 ± 3.4 ± 4.0)0

S1

eff = (32.2 ± 9.0 ± 2.6 ± 1.4)0 S1

eff = (32.2 ± 9.0 ± 2.6 ± 1.4)0

BG

Third error accounts for uncertainty from Dalitz model.

SM prediction

0.30 0.29 0.11 0.09CPA = - ± ± ±

[solution #1]Belle preliminary, arXiv:1007.3848 657 x 106 BB pairs_

Only in the φmass region

Only in the φmass region

0.04 0.20 0.10 0.02CPA = + ± ± ±

1 (all charm, J/ K0 …) = (21.1 ±

0.9) 0


KS0

S(all charm) = 0.673 ± 0.023 S( K0)

~ 0.9


Summary of New CPV search

All charm, B0-> J/K0 ...Reference point of SM

No clear deviation seenin all modes (1~2). Resultsare in agreement with SM.

New CPV effect can beseen with much larger data


Bellenew B0-> KS

Difference between Sin 21 in b -> ccs tree decays and b -> sqq penguin decays disappeared.

__

Physics motivation

.

• In SM interference between the tree and penguin diagrams can cause small direct CP violation in B+ -> J/ψK+ . SM: ACP (B+ -> J/ψK+) ≈ 0.3 %

• BSM contributions in b->s penguin loop can increase asymmetry

TreeBelle –2.6±2.2±1.7

Phys. Rev. D67, 032003 (2003)

BABAR +3.0±1.4±1.0Phys. Rev. Lett. 94, 141801 (2005)

D0 +0.75±0.61±0.30Phys. Rev. Lett. 100, 211802 (2008)

W/A +0.9±0.8 (PDG2009)

Previous measurementsof ACP (B+ -> J/ψK+) [%]

CP violation measurement in B+ J/ψ K+

Penguin


Signal = single GaussianBackground = ARGUS functionPeaking BG is negligibly small.

Complicated methodis used to obtain K+ reconstruction(detector) asymmetry.

Corrections for detectorasymmetry obtainedusing Ds

+-> + andD0-> K- + decays.

ACP (B+ -> J/ψ K+) = (-0.76 ± 0.50 ± 0.22) %

Result is in agreement with Standard Model prediction (~0.3%).

CP violation measurement in B0 J/ψ K+

772 x 106 BB pairs_



Measurement of B+ K+and B0

KS0

Radiative penguin diagram

In SM: S(b->s) ~ 0.03S ~ 2(ms/mb) sin(21)

772 x 106 BB pairs_

1176±5

136±175.4

9.6 K+

KS

B (B+-> K+ = (2.34 ± 0.29 ± 0.29 ) x 10-

6 B (B0-> Ks

= (2.66 ± 0.60 ± 0.32 ) x 10-

6

First measurement K+ :

A.Drutskoy et al (Belle) PRL 92, 051801 (2004)



CP violation measurement in B0

KS0

ACP (B+ -> K+ ) = (-0.03 ± 0.11 ± 0.08) %

S (B0 -> Ks ) = (+ 0.74 +0.72 +0.10) %

-1.05 - 0.24

A (B0 -> Ks ) = (+ 0.35 ± 0.58 +0.23 ) %

- 0.10

Ks

More results in H.J.Hyun talk: “Rare electroweak penguin decays in Belle”

Results are in agreement with Standard Model predictions.


Belle preliminary, ICHEP10

Measurement of B XS

Penguin loop diagram can potentially contribute to charmless B decays with .Difficult to predict: s,u,d quark content of meson and - ’ mixing.

_657 x 106 BB pairs

B (B-> XsMx< 2.6GeV/c2 = (26.1 ± 3.0 +1.9 + 4.0 (model) ) x 10-

5- 2.1 - 7.1

Acp (B-> XsMx< 2.6GeV/c2= - 0.13 ± 0.04 +0.02 - 0.03

Xs = K+ or Ks + up to 4

sum B vs M(Xs) Acp vs M(Xs)

Results should be explained theoretically, interpretation is not straightforward.


2.6 from 0(incl. syst.)


Search for B+ D- ℓ+ ℓ+

Majorana allows lepton number violating process, B+->h-ℓ+ℓ+

(h=,K,,K*,D,…), while this process is impossible with Dirac .Due to CKM matrix element, B+->D-ℓ+ℓ+ will be most sensitive.

Anyway, this process is expected to be very very suppressed.

Belle searched for decay B+->D-ℓ+ℓ+ (ℓ,ℓ)=(e,e),(e,),(,). This is first search!

Elegant idea to lookfor Majorana neutrino


Signal regions: no events are found in these 3 channels.

Eff. sys NBGexp

D-e+e+ 1.2% 8.6% 0.18±0.13 2.7

D-e++ 1.3% 10.1% 0.83±0.29 1.9

D-++ 1.8% 8.8% 1.44±0.43 1.1

UL(x10-6)

B⁺->D⁻e⁺e⁺

B⁺->D⁻e⁺µ⁺

B⁺->D⁻µ⁺µ⁺

Search for B+ D- ℓ+ ℓ+

772 x 106 BB pairsBelle preliminary, ICHEP10 _

First experimental upper limits for thesedecays.


(6S)

e+

e-

B

B_

e+ e- hadronic cross section

bb +-

e+ e- ->(4S) -> BB, where B is B+ or B0 meson

e+ e- -> bb ((5S)) -> B(*)B(*), B(*)B(*), BB, Bs(*)Bs

(*), (1S) , X …

where B* -> B and Bs* -> Bs

(4S)

_

_ _ _ _

2M(Bs)

_

CLEOPRL 54, 381 (1985)(4S)

(5S)

(cc,ss,uu,dd)----

KEKB, Belle,(5S): 2005 ~1.86 fb-1

2006 ~21.7 fb-1 , today ~121 fb-1


hadronic events at (5S)

u,d,s,c continuum

Bs* Bs Bs BsBs* Bs* channel

Bs events

b continuum5S) events

Hadronic event classification at (5S)

B0, B+ events

fs = N(Bs(*) Bs

(*)) / N(bb)

bb cross-section

f(Bs*Bs*)

1,2S) X

bb events

Bs*Bs*

Bs*Bs

BsBs

~ 90% Bs events


Bs-> Ds* Ds*Bs-> Ds* DsBs-> Ds+ Ds

-

sCP / s measurement from B (Bs -> Ds

+(*) Ds-(*))

s = sCP cos s

Due to CP violation directly measured s/s can be smaller than one

from Bs rate

B [Bs(CP+) – Bs(CP-)]. CPV in Bs decays in SM is small (small phase of Vts element).

In SM : cos s ≈ 1Assuming Bs -> Ds+(*) Ds

-(*) decays dominating CP=+

Belle preliminary, arXiv:1005.5177 L = 23.6 fb-1



Belle results on Bs0 decays at (5S)

B (Bs-> ) = (5.7 +1.8 +1.2) x 10-5-1.5 -1.1

B (Bs-> ) < 8.7x10-6 (90% CL)

Belle coll., PRL 100, 121801 (2008)

B (Bs-> Ds+-) = (3.67 +0.35 ± 0.65 ) x 10-3

- 0.33Belle coll., PRL 102, 021801 (2008)

Belle coll., PRL 104, 231801 (2010)

B (Bs->J/) = ( 3.1 1.2 + 0.5 0.38 (fs)) x 10-4

Belle coll.,

arXiv:0912.1434

B ( Bs-> K+K-)=( 3.8 +1.0 0.5 0.5 (fs)) x 10-5 - 0.9

Belle coll., arXiv:1006.5115

Obtained results on Bs decays are in good agreement with expectations

B (Bs->J/) = ( 3.32 0.87 +0.32 0.42 (fs)) x 10-4 - 0.28

- 0.6

Branching fractions for lepton flavor changing decays are negligibly smallin the Standard Model even taking into account neutrino oscillations.

(EPJ C8 513 (1999))

Observation of LFV is clear signature of New Physics.

Several extensions of the SM predict LFV decays. Some BSM models (SUSY-seesaw, SUSY-GUT, specific coupling neutral Higgs) predict rather large branching fractions which are comparable with current experimental sensitivity.

Tau lepton decays => good place to search for BSM

(or e)

W-

(or e)

54

2

2

2

10)(

WSM m

mBr

Lepton flavor violation (LFV) in tau decays


e+e+

(signal side)

1 prong + missing ( tag side)

e e

generic decay

3 ellipse signal regionThe size was obtained

from MC (resolution).

)( 22 pEM

CMbeam

CM EEE

Number of BG events is estimatedusing sideband data and MC

Signal extraction: M- E plane mM ~

0~E

Experimental method to search for decay + +


Eff. NBGexp UL Eff. NBG

exp x10-8

8.2% 0.63±0.37 3.6 ’ 8.1% 0.00+0.16-0.00 10.0

6.9% 0.23±0.23 8.6 ’ 6.2% 0.59±0.41 6.6

comb 2.3 ’ comb

3.8

e 7.0% 0.66±0.38 8.2 e’ 7.3% 0.63±0.45 9.4

e 6.3% 0.69±0.40 8.1 e’ 7.5% 0.29±0.29 6.8

ecomb 4.4 e’ comb 3.6

4.2% 0.64±0.32 2.7 e 4.7% 0.89±0.40 2.2

UL(x10-8) UL(x10-8)


Search for decays + ℓ+ P0 (0,,’) with 901 fb-1


Eff. NBGexp Eff. NBG

exp

e- 7.6% 0.29±0.15 1.8 e-K*0 4.4% 0.39±0.14 3.2

7.1% 1.48±0.35 1.2 K*0 3.4% 0.53±0.20 7.2

e- 4.2% 0.47±0.19 3.1 e-K*0 4.4% 0.08±0.08 3.4

3.2% 0.06±0.06 8.4 K*0 3.6% 0.45±0.17 7.0

e- 2.9% 0.30±0.14 4.8 2.4% 0.72±0.18 4.7

UL(x10-8) UL(x10-8)

Search for decays + ℓ+ V0 (0,K*0) with 854 fb-1



Our sensitivity reaches O(10-8)!

New upper limits for LFV tau decays

The world best upper limits are obtained. No evidence of LFV tau decays.


Potential models,energy splitting

s2

cc

L

L (S1 S2)

L=0 0-

1-

L=1

J/c

hc1+

2S1-

’’c

1S

c0

c1

c2

1+

0+

2+

Mas

s

S12

0-

1P

s1

Energy splitting: singlet and triplet.

Potential models predictmasses of conventional states with fixed quantum numbers.

Generally, accuracy of mass predictions should notexceed few tens of MeV/c2.


Charmonium spectroscopy

28

’

Even

ts/1

0

Mev

Belle

X(3872)

X(3872)

230 pb-1

PRL 91 (2003) 262001

304M B’s

PRL 93 (2004) 162002

X(3872) > J/ +- decay

First observed by Belle in B± -> K±(J/+-).Then confirmed by CDF, D0 and BaBar.

455M B’s

PRL 93 (2004) 072001

X(3872)

220 pb-1

X(3872)’

M(J/ +-)

PRD 77 (2008) 111101


http://www.slac.stanford.edu/BFROOT/BABAR.html

DD*

DDX(3872)

X(3872) interpretation ?

< 1 MeV/c2

Interpretations of X(3872) and X(4260) are unclear. Most popular for X(3872) ismolecular interpretation (X(3872)-> J/ branching fraction is small for 1++ ’c1 ).

Y(4260)

Is X(3872)D*D molecular?


Conventional and unconventional mesons

1. Conventional quark- antiquark mesons (qq).

2. Glueballs (gg, ggg). Lightest glueballs JPC = 0++ and 2++.

3. Hybrid mesons (qqg). Ground states JPC = 0-+, 1-+, 1--,

2-+.4. Tetraquarks (qqqq). Large binding energy. Non-qq flavor?

5. Molecular states (qq qq). Small binding energy. Deuteron-like.

6. Mixture of these states. Small admixture of exotic state.

Exotic states can be separated using information on masses,widths, quantum numbers, production and decay modes (rates).

Theoretical calculations, potential models, lattice calculations.



3.6σ 424fb–1

3.5σ

M(γ’)M(γJ/)

X(3872)→γJ/ψ X(3872)→γψ’ PR

L10

2, 1

32001

(2

00

9)

4.15.3

'

JXBR

XBR

Experimental results on X(3872)

2. CDF angular analysis: JPC= 1++, 2-+ favored

1. Bound state scenario supported by: 10)(

)( 0*0

JXBR

DDXBR

3. Large isospin violation: 3.04.00.1

/ 0

JXBR

JXBR

4. Radiative decays are important to test molecular interpretation. E. S. Swanson, Phys. Rept. 429, 243 (2006) :

4.15.3'

JXBR

XBR< 0.01 for molecular

The BaBar result seems to be serious problem for molecular interpretation.

BaBar (2009)

32

6101.06.08.1

)3872(

JXBRKXBBR

Belle, 256 fb-1 (hep-ex/0505037)

Belle results on radiative X(3872) decays

X(3872)→γJ/ψ

X(3

87

2)→

γψ

’

B+->X(3872)K+ B0->X(3872)Ks0

ψ’->e+e-,μ+μ-

ψ’->J/ψπ+π-

X(3872)Ks0

X(3872)Ks0

61012.046.078.1

)3872(

JXBRKXBBR CL%90104.2

)3872(

@6

00

JXBRKXBBR

CL%90104.3

')3872(

@6

XBRKXBBR CL%90106.6

')3872(

@6

00

XBRKXBBR

CL%901.2

'@

JXBR

XBR

No X -> ’ signal was observed by Belle. Upper limit is smallerthan BaBar ratio. However uncertainties are too large to conclude.

33

Belle preliminary, ICHEP10 772 x 106 BB pairs_

Many new interesting Belle results are not included in this talk due tolimited time. Sorry for that.

Search for CP violation in D decays PRL 104 181602 (2010)

B -> D(*)+/0 arXiv: 1005.2302

B -> arXiv: 1006.4201

Bs -> J/, J/’, J/ f0 arXiv: 0912.1434

B0-> Ds- K+ , B0-> Ds

+ - arXiv: 1007.4619

and others …

Other Belle results


Conclusions

Belle continues active studies of B, D and decays with full data samples collected at (4S), (5S), (1S), (2S), and (3S).

No evidence of Beyond Standard Model effects was found in recentBelle measurements.

Generally, current measurements of B, D, decays are equivalentto New Physics (for some of models) around 1 TeV scale.

Belle II experiment is needed to move further.Belle II experiment is needed to move further.


Background slides


W exchange diagram

Final state interactions (FSI)b to u diagram with Ds

Within factorization approachCabbibo-Kobayashi-Maskawamatrix element Vub can be obtained from ratio:

Bf(B-> Ds +) / Bf(B-> Ds D+)=

(0.424 ± 0.041) x |Vub/Vcb|2

- -

It is expected (but not proved)that W exchange diagramdominates.

New measurement B0-> Ds K+ and B0-> Ds - decays- +

Specific diagrams : it’s importantto perform precise measurements


New measurement B0-> Ds K+ and B0-> Ds - decays +-

B (B0-> Ds K+)= (1.91 ± 0.24 ± 0.17) x 10-5

657 x 106 BB pairs_

Belle preliminary

B (B0-> Ds -)= (1.99 ± 0.26 ± 0.18) x 10-5 +

-

Ds K+ - -Ds K+ Ds - + +Ds -

Results are in agreement with previous measurements, accuracy is better.


a. drutskoy, itep, moscow recent results from belle qfthep’ 2010, golitsyno, moscow, russia,...

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