29 june 2002emmanuel monnier - c.p.p.marseille, u. of chicago beach2002 1 review of hyperon in ktev...

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

1

Review of Hyperon in KTeV

and other recent results

Hyperon beta decays Hyperon radiative decays Kaons rare decays Conclusions

(on behalf of the KTeV collaboration)

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

2

The KTeV Collaboration

E. Cheu, J. Hamm, S.A. Tagger, J. Wang - University of Arizona

K. Arisaka, W. Slater, A. Tripathi, S.E.Turner - University of California, Los Angles

R. Barbosa, C. Escobar, P. Gouffon, R. Zukanovich-Funchal - University of Campaninas/University of Sao Paulo

E. Blucher, C. Bown, S. Bright, A. Glasov, G. Graham, J. Graham, R. Kessler, E. Monnier, V. Prasad, B. Quinn, A. Roodman, P.S. Shawhan, N. Solomey, Y.W. Wah, B. Winstein, R. Winston, E. Zimmerman - University of Chicago

A. R. Barker, J. LaDue, P. Mikelsons, U. Nauenberg, P.A. Toale, J.-Y. Wu - University of Colorado, Boulder

E. C. Swallow - Elmhurst College

L. Bellantoni, R. Ben-David, G.J. Bock, S. Childress, R. Coleman, M. B. Crisler, R. Ford, Y. B. Hsiung, D. A. Jensen, P.L. Mcbride, H. Nguyen, V. O’Dell, M. Pang, R. Pordes, E. Ramberg, R. E. Ray, P. Shanahan, R. Tschirhart, H. B. White, J. WhitmoreFermi National Laboratory

K. Hanagaki, S. Hidaka, T. Nakaya, M. Sadamoto, K. Senyo, I. Suzuki, T. Yamanaka - Osaka University

A. Bellavance, M. D. Corcoran - Rice University

I. Albuquerque, S. Averitte, J. Belz, D.R. Bergman, E. Halkiadakis, A. Lath, S. Schnetzer, S. Somalwar, R. L. Stone, R. Tesarek, G. B. Thomson - Rutgers University

M. Arenton, G. Corti, B. Cox, A. Golossanov, K. Hagan, V. Jejer, S. Ledovskoy, A. P. McManus, K. Nelson - University of Virginia

A.Alavi_Harati, T. Alexopulos, A. R. Erwin - University of Wisconsin, Madison

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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The KTeV detector

●High resolution CsI calorimeterσE/E<1% at <Eγ>=10GeV, π/e>700

●High resolution spectrometerChamber resolution: ~100 µm

●Large TRDRejection π/e>200

●Photon veto

●Intense beam on BeO target5x1012 protons/mn kaons, hyperons

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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Data taking periods

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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KTeV Hyperon Program

●Hyperon beta decays: ●ee and (+ anti mode)

●Hyperon radiative decays●eep

●parameters (lifetime, mass)

●Rare decay search,(S=2)●p

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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●2 neutral clusters:()

●2 tracks:(p)

●1 high momentum track: (p)

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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Allowed beta decays

n p

(red arrows)

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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ee

Signal = 626Signal = 626 +/-+/- 25 events25 events

Background = 60Background = 60 +/- +/- 8 events 8 events

0L

-00

K

pe ,

background

ev

* KTeV first measured B.R = (2.71* KTeV first measured B.R = (2.71 ++ 0.22 0.22 ++ 0.31) x 100.31) x 10-4-4 PRL 82; 3751; (1999) PRL 82; 3751; (1999)

Theoretical (SU3) predicted B.R = (2.61 Theoretical (SU3) predicted B.R = (2.61 ++ 0.11) x 100.11) x 10 -4 -4

B.R = (2.54B.R = (2.54 + + 0.11 0.11 + + 0.16) x 100.16) x 10-4-4 -- --Stat SysStat Sys

--

--

*

--

pee

p

_

_

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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Baryon beta decay

● A(pA(pAA) ) B(p B(pBB) + l + ) + l + q = pq = pAA - p - pBB

● Matrix element:Matrix element:M = 2 = 21/21/2 G G <<B B |J|JAAuul l (p(pll) ) vv (p (p))

● V-A currentV-A current

<<BB |J |JAA = u = uB B {{ff11(q(q22)) + i + i ff22(q(q22)/)/MMAA qqv v + + ff33(q(q22)/)/MMAA q q

+ + gg11(q(q22)) + i + i gg22(q(q22)/)/MMAA qqv v + + gg33(q(q22)/)/MMAA q q

uuAA

● =0.98 for p

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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g1/f1 = 1.32 ± 0.210.17(stat) ± 0.05(syst)

f2/f1 = 2.0 ± 1.2 ± 0.5

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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ee and ee (99)_ ___

1220 ee 105 ee

_ _

KTeV preliminary

KTeV preliminary

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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●From 97 data set: 5 Evts

●Normalisation: ee

● Br=(3.5 ± 2.01.6(stat) ± 0.5

1.0(syst))10-6

● 99+97 not enough for form factor,

● Need few hundreds

_

99 data

Mass (p+0)

Mas

s (

+0-

)

• Correct Charge• Wrong Charge• Final Candidates

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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Events with:●2 photons

(cluster)● (2 tracks)●mass constraint● from target

M (GeV/c2)

M (GeV/c2)

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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In the peak:●4045 events●804 background●Norm:

●BR((3.34±.05±.09)x10-3

M (GeV/c2)

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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= -0.63 +/- 0.08 +/- 0.05

Measurement of

●3 steps process

●Depolarisation of 1/3 for

●Phys. Rev. Lett. 86, 3239 (2001).

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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Polarization at 800 GeV

●Reconstruct

●Extract directions x,y,z (in rest frame)

●Ratio for two magnet settings is:

1 + i Pi (cos i)(with i=x,y,z)

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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Polarization results

****

*

*

_

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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evts 33100,1)( N

evts 1063000,130,1)( 0 N

Winter’97 data(Contained 1 cluster data)

00

3-x10)04.094.0()(

)(

oBR

BR

(stat only)

3PDG 10x]16.006.1[BR

Preliminary BR

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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ee

KTeV preliminary

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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KTeV preliminary

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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Kaon rare decay in KTeV

●Results from 1997 data

●Now combined analysis

●2.5 to 3 times more data

●New combined results

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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●Double dalitz decay

●Angular distributions sensitive to Scalar/pseudoscalare coupling

●ee masses linked to form factors

●Normalisation is KL-ooo with 2 o dalitz decay

●97: 10506 signal events 52446 normalisation events

●99: 17448 signal events 79640 normalisation events

●97+99: 27954 signal / 132086 norm B(o-e+e-e+e-)/B(o-e+e-)2

= 0.2252±0.0015±0.0059

B(o-e+e-e+e-)/B(o-) = (3.274±0.022±0.197)x10-5

Form factor analysis ongoing, results soon

o-e+e-e+e- from KL-ooo

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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● angle of ee plane

●(cos2+Csin2)(SM: = -0.18, C = 0)

●No indication of CP violation

Parity analysis of o**

coupling

KTeV preliminary

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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KL-+-

● Br(KL-+-)=(3.62±0.04±0.08)x10-7

● Normalized to KL-+-o

● K*=-0.160-0.028

+0.026

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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KL-e+e-

●Br(KL-e+e-)=

(10.13±0.04±0.06±0.29)x10-6

●Normalized to KL-oooD

●93383 Sig. / 5306073 Norm.

●K*=-0.192±0.011±0.009(syst)

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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Result on K*

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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KL-e+e-

+-

●Normalized to KL-+-oD

●93383 Sig. / 5306073 Norm.

●Br(KL-e+e-+-)=

(2.61±0.23±0.18)x10-9

(VMD prediction is 2.34x10-9 )

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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KL-e+e-

+-

●No CP violation effect in angular distribution

●Search for lepton flavor violation:

●Br(KL-e±e±±±)<(4.12)x10-11

(90% C.L., preliminary)

●Form factor analysis soon

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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Other recent results

●KL-+-e+e-

●5056 ± 71 events

●A=(13.3±1.4±1.0)% (preliminary)

●+ Vector form factor parameters

●KL-o±e-+ :

●Br(KL-o±e-+)<(3.34)x10-10

(90% C.L., preliminary)

29 June 2002 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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Conclusion

●KTeV has produced many results●Hyperon decays

●Kaon rare decays

●High statistic modes

●But KTeV has still a lot to produced from the 99 data set and many results will come out soon…