recent results from kloe at da ne xlii rencontres de moriond on electroweak interactions and unified...

Recent results from KLOE at DANE

XLII Rencontres de Moriond on ELECTROWEAK INTERACTIONS AND UNIFIED THEORIES

La Thuile, Aosta, Italy, 10 – 17 March 2007

Antonio Di Domenico* on behalf of the KLOE Collaboration

*Università di Roma “La Sapienza” and INFN sezione di Roma, Italy

2XLII Rencontres de Moriond on ELECTROWEAK INTERACTIONS AND UNIFIED THEORIES, La Thuile, Italy, 10 – 17 March 2007A. Di Domenico

•e+e b W = m = 1019.4 MeV•highly pure KS,KL, K+, K beams

Kaons at a -factory

pK = 110 MeV/c S = 6 mm L = 3.5 m

The detection of a kaon at large (small) times tags a KS (KL) possibility to select a pure KS beam (unique at a -factory, not possible at fixed target experiments)

decay mode BR

KK 49.1%

KSKL 34.1%

KL,SKS,L

t1 t2

t=t1 t2

f2

f1

• ~106 neutral kaon pairs per pb-1

produced in an antisymmetric quantum state with JPC = 1

pKpKpKpK

N

pKpKpKpKi

SLLS

2

2

1 0000


DANE performance up to Dec 2005

Integrated Luminosity Day performance: 7-8 pb-1

Best month L dt ~ 200 pb1

Total KLOE L dt ~ 2500 pb1 (2001 - 05)

L=1.4 x 1032 cm2s1

Off peakrun

Peak Luminosity

~2.5109 KSKL pairs ~3.6109 K+K- pairs


CalorimeterCalorimeter Drift chamberDrift chamber

E/E 5.7% /E(GeV)

t 54 ps /E(GeV) 50 ps

(relative time between clusters)

~ 2 cm (0 from KL )

p/p 0.4 % (tracks with > 45°)

xhit 150 m (xy), 2 mm (z)

xvertex ~ 1 mm

The KLOE detector

4 m diameter × 3.3 m length90% helium, 10% isobutane12582/52140 sense/total wiresAll-stereo geometry

Lead/scintillating fiber4880 PMTs98% coverage of solid angle

Superconducting coil

B = 0.52 T


KS tagged by KL interaction in EmCEfficiency ~ 30% (largely geometrical)KS angular resolution: ~ 1° (0.3 in )

KS momentum resolution: ~ 2 MeV

KKLL “crash”“crash”

= 0.22 (TOF)= 0.22 (TOF)

KKSS ee

KL tagged by KS vertex at IPEfficiency ~ 70% (mainly geometrical)KL angular resolution: ~ 1°KL momentum resolution: ~ 2 MeV

KKSS

KKLL 2 2

KS and KL Tagging


KS +- KS +-

+-0

KS e+e-

Minv [ee hypo] (MeV)

Search for the decay KS e+e-

event selection ((1.32 fb-1 ) )

• KS tagged by KL crash

• 2 tracks from IP to EmC with Minv [e+e- hypo] > 420 MeV

2-like variable based on EmC:

and of (Tclu-L/c) for the 2 particles

E/p

transverse distance between track impact point and the closest EmC clusterfurther bck rejection

• P* ( hypo) in the KS rest frame 220 MeV

• Mmiss 380 MeV to reject residual

SM prediction is low but precise BR(KS e+e-) = 1.610-15 [Ecker, Pich 91]leaving room for possible new physics effects to be detected

MC


KS +- KS +-

+-0

KS e+e-

Minv [ee hypo] (MeV)


event selection ((1.32 fb-1 ) )

• KS tagged by KL crash

• 2 tracks from IP to EmC with Minv [e+e- hypo] > 420 MeV

2-like variable based on EmC:

and of (Tclu-L/c) for the 2 particles

E/p

transverse distance between track impact point and the closest EmC clusterfurther bck rejection

• P* ( hypo) in the KS rest frame 220 MeV

• Mmiss 380 MeV to reject residual

SM prediction is low but precise BR(KS e+e-) = 1.610-15 [Ecker, Pich 91]leaving room for possible new physics effects to be detected

MC

signal box


optimization of signal box definition on MC: (492 Minv 504) MeV and 2 20 in the signal box, we find Nobs = 3 and BKG = 7.1±3.6 from these UL(sig) = 4.3 @ 90% CL ( without background subtraction UL(sig) = 6.68 @ 90% CL )

sig = presel sel -rad (E* < 6 MeV) = 0.785 0.888 0.8 = 0.558 = 0.6 , N~ 1.5108

UL(BR) = UL(sig) sig

BR

N

normalize signal counts to KS () counts in the same data set

BR(KS e+e-()) < 2.1 10-8 @ 90% CL

KLOE preliminary:

CPLEAR: < 1.4 10-7



KS

event preselection (1.6 fb-1 ) KS tagged by KL crash 2 and only 2 ’s with E 7MeV cos() 0.95

(T-R/c) 5t

BR(KS ) is an important test of PT [PRD 49 (1994) 2346]

event selection kinematic fit PKS () = PKS(KLcrash)

M = MKS

T = R/c for both ’s

QCAL veto

BR = N sig

BR20

N20

= presel sel= 0.83 0.63 = 0.52

20= 0.65

• Data- MC

KS

(QCAL veto) ~ 100% on signal (very small accidental loss)

KS 20 (2 bckg)


count signal events fitting the 2D plot of M and cos in the KS cms with MC shapes

• Data- MC signal background

M (MeV)

cos *

M (MeV)

• Data- MC

signal free from KL bckg

KS

KL control sample selected to further check the energy scale on data-MC

KS 20 (2 bckg)


BR = (2.35 ± 0.14) 10-6

2.7 from NA48 result

1.5 in agreement with PT O(p4) prediction

KS

KLOE preliminary:


Eclu(MeV)

Ecl

u -E

eva

l (M

eV)

KLe

inclusive selection (328 pb-1 ):• KL tagged by KS

• (Emiss-|Pmiss|) in different mass hypothesis to remove ~90% of bck

• ToF to separate e/ (after PID ~ 0.7% contamination)

2 106 Ke3

• KL vtx -> comparing ToF of KL and the -cluster time

• cluster position to close the kinematic and evaluate E->p

= 0 = (pK-p-pe-p)2

Signal Ke3 out of acceptancenot radiative Ke3

+-0

K3

measurement of BR and the Direct Emission term in the spectrum radiative sample selection:

• this cut to remove not radiative Ke3

• Eclu 25 MeV to remove accidentals• NN trained with EmC infos to remove K3 and

bck reduction:

KL control sampleto check efficiency, energy and vertex resolutions

MC


KLe

BR(Ke3; E* 30 MeV, *e- 200)BR(Ke3())

R =

R = (0.92 ± 0.02stat ± 0.02syst)%

with 2.5 pb-1 ± 0.01stat%

KLOE preliminary:

using DE- spectrum calculated in PT O(p6) [Gasser et al. EPJ 40C (2005)205 ]

theory [Gasser et al.,EPJ 40C (2005)205 ]:

R = (0.96 ± 0.01)% (uncertainty mainlydue to the DE term)

•fit 2D plot of E* and *e- with the MC shapes•we measure:

E*(MeV)

*e-

(deg)

• Data- MC

backgroundSignal

*e-

deg

)

E*(MeV)

MC

BRDE < 2.510-5 @ 90% CL

KLOE preliminary:BRDE = (-3.1 ± 3.0) 10-5

KTEV(05) R=(0.916 ± 0.017)% NA48(05) R=(0.964 ± 0.013)%


KL3 form factor slope 0

MeV

MeVmpE

MeVpE

missmiss

missmiss

10|)||,min(|

10),(

10)),((

21

23222

22

0

)),(,),(( 21 missmissmissmiss peEpeE

background contamination reduced to 1.5% 1.5% using NN and TOF measurements

relevant for Vus and to test e/ universality

4(MeV) 4(MeV)

3(M

eV

)

3(M

eV

)

4% contamination4% contamination further cut on

Emiss(+,-)-|pmiss|

Emiss(-,+)-|pmiss|

Selection (328 pb-1 ): KL tagged by KS

veto on

veto on

veto on Ke3

MC


separation at low energies is difficult 0 slope obtained by fitting the E distribution, combined fit with KLe3 results for ’+ , ’’+

0 = (15.6 ± 1.8stat ± 1.9syst) 10-3

KTeV PRD 70(2004)PRD 70(2004) 0 = (12.8± 1.8)10-3 NA48 preliminarypreliminary 0 = (9.1± 1.4)10-3

ISTRA+ PLB 589(2004) 0 = (17.1± 2.2)10-3

correlation matrix’+ ’’+ 0

1 -0.95 0.31X 1 -0.41X X 1

’+ = (25.6 ± 1.8) 10-3

’’+ = (1.44 ± 0.79) 10-3

[PLB 636 (2006) 166]DataFit

22/ndf = 21/31/ndf = 21/31

new !!

residuals

E(MeV)

KL3 form factor slope 0

KLOE preliminary: ~ 5-10% with 2.5 fb-1

E(MeV)


KL [GF()/GF(e)]2 =1.0065(98) cfr with PDG04 1.047(14)K± [GF()/GF(e)]2 =0.984(25) cfr with PDG04 1.004(16)

SlopesKL e3 KL 3 KS e3 K e3 K 3

BR 0.4008(15) 0.2699(15) 7.046(91)×10-4 0.05047(92) 0.03310(81)

50.84(23) ns 89.58(5) ps 12.367(78) ns

Vus f+(0) from KLOE results

• f+(0)=0.961(8) Leutwyler and Roos Z.

[Phys. C25, 91, 1984]

• Vud=0.97377(27) Marciano and Sirlin

[Phys.Rev.Lett.96 032002,2006]

From unitarity

Vus×f+(0) = 0.2187(21)

<V<Vusus××ff++(0)>(0)>KLOE AV. KLOE AV. = 0.2158±0.0006 (~ 0.3%)= 0.2158±0.0006 (~ 0.3%)

usi

ng f

+(0

) =

0.9

61

(8),

Vud

= 0

.97

37

7(2

7)

=

1 –

V=

1 –

Vud

ud22 –

V –

Vus

us22 =

(-1

3±

10

) =

(-1

3±

10

) 1

01

0-4-4

|Vus|f+(0)

FlaviaNet c

ode

FlaviaNet c

ode

e/ universality

KLOE final KLOE preliminary KLOE final

KLOE prelim.


Fit results, no constraint 2/ndf = 0.35/1P(2) = 0.56

Vus = 0.2239(16) Vud = 0.97377(27)

=1–Vud2 –

Vus2=(1.6±1.2 )10-3

Vus – Vud plane

Vus/Vud = 0.2286(+27 -15)

Vus = 0.2246(20) Kl3 KLOE, using f+(0)=0.961(8)

Vud = 0.97377(27) Marciano and Sirlin Phys.Rev.Lett.96 032002,2006

InputsInputs

get |Vus/Vud| from K, widths: (K ())

( ())

Vus

Vud

fK2

f2

2

(Marciano PRL93 231803, 2004) from the KLOE analysis of 175 pb-1 [PLB 632,76]

BR(K+ ) = 0.6366(9)(15) from lattice [MILC Coll. 2006]

fK/fp = 1.208(2)(+7 -14)

Fit results, unitarity constraint2/ndf = 3.74/2, P(2) = 0.15, Vus = 0.2262(9), Vud = 0.97407(22)

Vud

Vus

fit with unitarity

fit

Vud

Vus

Vus /Vud


Recent KLOE published results on kaons

KSKL QM and CPT tests PLB 642(2006) 315

Bell-Steinberger rel. CP and CPT violation parameters JHEP 0612(2006)011

KSe BR, charge asymmetry, form factor slope

PLB 636(2006) 173 NEW PDG06

KS EPJ C48(2006) 767 NEW PDG06

KS upper limit on BR at 10-7 PLB 619(2005) 61 NEW PDG06

KL e Absolute BR’s

KL lifetime from Sum BR’s =1

PLB 632(2006) 43 NEW PDG06

KL lifetime from KL PLB 626(2005) 15 NEW PDG06

KL BR to 1.1% PLB 638(2006) 140 NEW PDG06

KLe form factor slopes PLB 636(2006) 166 NEW PDG06

K+ Absolute BR PLB 632(2006) 76 NEW PDG06


Measurements of KS K

L observables used for the CPT test from unitarity :

KS

00KS

KS

kl3

S

L B(K

Ll3) (A

S+A

L)/4i Im x

S

L

KL

S

L

KL

CPT test: the Bell-Steinberger relation

kl3

main uncertainty now comes from

i i

i i

SW

SW

kk

kbk

Nδε

ε

1tan1

tan121111

2

kbk

kkN

KBb

k

SW

L

LS

12

tan11 222

(KS)(K

S)


Re Im CPLEAR: Re Im

KLOE result:JHEP12(2006) 011

Assuming =0, i.e. no CPT viol. in decay:GeV < M < GeV at 95% C.L.

LSSL

iMM

iM

2

22

1 00

00

KMKMM

KK

CPT test: the Bell-Steinberger relation


tKKtKK

tKKtKKtI N

0000

200

200

2

2,22,22

2,22,2;2,2

KSKL: test of quantum coherence


tKKtKK

tKKtKKtI N

000000

200

200

2

2,22,221

2,22,2;2,2


edecoherenc total 1

QM 0

00

00

Decoherence parameter:


tKKtKK

tKKtKKtI N

000000

200

200

2

2,22,221

2,22,2;2,2

• Fit including t resolution and efficiency effects + regeneration• S, L m fixed from PDG

From CPLEAR data, Bertlmann et al. (PR D60 (1999) 114032) obtain:

KLOE result: with 2.5 fb-1 :


6SYSTSTAT00 104.01.20.1

7.04.000

6STAT 108.0

as O(high sensitivity to

edecoherenc total 1

QM 0

00

00

Decoherence parameter:

PLB 642(2006) 315

In the B-meson system, BELLE coll.(quant-ph/0702267) obtains:

057.0029.000

B

(380 pb-1)


|| could be at most: 352

210~10

PLANCKMEO

LLSSSLLS KKKKKKKKi

In presence of decoherence and CPT violation induced by quantum gravity (CPT operator “ill-defined”) the definition of the particle-antiparticle states could be modified. This in turn could induce a breakdown of the correlations imposed by Bose statistics (EPR correlations) to the kaon state [Bernabeu, et al. PRL 92 (2004) 131601, NPB744 (2006) 180]:

KSKL: CPT violation in correlated K states

C.L. 95%at 101.2

106.04.3

109.01.1

3

48.40.5

47.83.5

SYSTSTAT

SYSTSTAT

KLOE result ( measured for the first time)PLB 642(2006) 315

with L=2.5 fb-1: 4

4

100.2

108.2

STAT

STAT

Re

Im

0

0


Conclusions •KLOE has obtained new preliminary results on: - BR(KS e+e-()) < 2.1 10-8 @ 90% CL

- BR (KS ) = (2.35 ± 0.14) 10-6

- KL e -> R = (0.92 ± 0.02stat ± 0.02syst)% , BRDE < 2.510-5 @ 90% CL

- KL3 form factor slope 0= (15.6 ± 1.8stat ± 1.9syst) 10-3

•Recent KLOE measurements greatly improve knowledge of VUS ;•Final results on K

l3 , and K lifetime (two different methods see P. Massarotti’s talk) are under way;

•Several parameters related to CPT and QM tests are measured at KLOE, Re( and Im( for the first time;

•With the analysis of the full data sample (2.5 fb-1) KLOE will further improve all results;

•KLOE and DANE are going to be upgraded.


KLOE-2 Physics issues:• Neutral kaon interferometry, CPT symmetry & QM tests• Kaon physics, rare KS decays• ,’ physics• Light scalars, physics• Hadron cross section at low energy, muon anomaly• (baryon electromagnetic form factors, e+e- pp, nn,

KLOE-2 at upgraded DANE

KLOE-2 Detector upgrade issues:• Inner tracker R&D• Calorimeter, increase of granularity• FEE maintenance and upgrade• Computing and networking update• tagging system • etc.. (Trigger,software, …)

Proposals to upgrade DANE in luminosity (and energy):Crabbed waist scheme at DANE (proposal by P. Raimondi)- increase L by a factor O(5)- requires minor modifications- relatively low cost

- Experimental test at DANE in autumn 2007- If successful KLOE-2 data taking could start already in 2009

recent results from kloe at da ne xlii rencontres de moriond on electroweak interactions and unified...

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