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Review of Hyperon in KTeV and other recent results

Review of Hyperon in KTeV and other recent results. (on behalf of the KTeV collaboration). Hyperon beta decays Hyperon radiative decays Kaons rare decays Conclusions. The KTeV Collaboration. E. Cheu, J. Hamm, S.A. Tagger, J. Wang - University of Arizona

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Review of Hyperon in KTeV and other recent results

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  1. Review of Hyperon in KTeVand other recent results (on behalf of the KTeV collaboration) Hyperon beta decays Hyperon radiative decays Kaons rare decays Conclusions 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. Whitmore Fermi 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 • Alavi_Harati, T. Alexopulos, A. R. Erwin - University of Wisconsin, Madison Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  3. The KTeV detector • High resolution CsI calorimeter σE/E<1% at <Eγ>=10GeV, π/e>700 • High resolution spectrometer Chamber resolution: ~100 µm • Large TRD Rejection π/e>200 • Photon veto • Intense beam on BeO target 5x1012protons/mn  kaons, hyperons Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  4. Data taking periods Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  5. KTeV Hyperon Program • Hyperon beta decays: • XoS+e-ne and XoS+m-nm (+ anti mode) • Hyperon radiative decays • XoSog, XoLog , XoLopog, SoLoe+e-,Lopp-g • Xo parameters (lifetime, mass) • Rare decay search,(DS=2) • Xopp Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  6. XoLopo • 2 neutral clusters: • (po gg) • 2 tracks: • (Lo pp-) • 1 high momentum track: (p) Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  7. Allowed beta decays (red arrows) n p L0 S- S+ S0 X- X0 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  8. B.R = (2.54 + 0.11 + 0.16) x 10-4 - - Stat Sys _ XoS+e-ne * Signal = 626+/-25 events Background = 60 +/-8 events Theoretical (SU3) predicted B.R = (2.61 +0.11) x 10 -4 - XoLopo Lopp- _ XoS+e-ne S+ppo * KTeV first measured B.R = (2.71+0.22 +0.31) x 10-4 PRL 82; 3751; (1999) - - Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  9. Baryon beta decay • A(pA)  B(pB) + l + n , q = pA - pB • Matrix element: M = 21/2G <B |Jm (0)| A> ul (pl) gm( 1 + g5 ) vn (pn) • V-A current <B |Jm (0)| A> = uB {f1(q2)gm + if2(q2)/MAsmn qv + f3(q2)/MA qm + g1(q2)gm + i g2(q2)/MAsmn qv + g3(q2)/MA qm } g5uA • a=0.98 for S+pp- Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  10. g1/f1 = 1.32 ± 0.210.17(stat) ± 0.05(syst)f2/f1 = 2.0 ± 1.2 ± 0.5 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  11. _ __ _ XoS+e-ne and XoS+e+ne (99) _ _ 1220XoS+e-ne 105XoS+e+ne KTeV preliminary KTeV preliminary Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  12. _ XoS+m-nm • From 97 data set: 5 Evts • Normalisation: XoS+e-ne • Br=(3.5 ± 2.01.6(stat) ± 0.51.0(syst))10-6 • 99+97 not enough for form factor, • Need few hundreds 99 data Mass (p+p0m-) • Correct Charge • Wrong Charge • Final Candidates Mass (p+p0) Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  13. XoSog Logg Events with: • 2 photons (cluster) • Lo (2 tracks) • Xo mass constraint • Xo from target MLg (GeV/c2) Mgg (GeV/c2) Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  14. XoSog Logg In the peak: • 4045 events • 804 background • Norm: XoLopo • BR(XoSog) = (3.34±.05±.09)x10-3 M (GeV/c2) Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  15. Measurement of aX->Sg • 3 steps process • Depolarisation of 1/3 for So->Lg • Phys. Rev. Lett. 86, 3239 (2001). a = -0.63 +/- 0.08 +/- 0.05 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  16. Xo Polarization at 800 GeV • Reconstruct XoLopo • Extract Lo directions qx,qy,qz (in Xo rest frame) • Ratio for two magnet settings is: 1 + ai Pi (cos qi) (with i=x,y,z) Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  17.     * * * * * _ Xo  Xo * Polarization results _ Xo Xo Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  18. (stat only) Xo->LgPreliminary BR Winter’97 data (Contained 1 cluster data) Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  19. Xo->Sog->Le+e-g KTeV preliminary Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  20. Xo->Lpog KTeV preliminary Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  21. Kaon rare decay in KTeV • Results from 1997 data • Now combined analysis • 2.5 to 3 times more data • New combined results Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  22. po->e+e-e+e- from KL->popopo • Double dalitz decay • Angular distributions sensitive to Scalar/pseudoscalare coupling • ee masses linked to form factors • Normalisation is KL->popopo with 2 po dalitz decay • 97: 10506 signal events 52446 normalisation events • 99: 17448 signal events 79640 normalisation events • 97+99: 27954 signal / 132086 norm • B(po->e+e-e+e-)/B(po->e+e-g)2= 0.2252±0.0015±0.0059 • B(po->e+e-e+e-)/B(po->gg) = (3.274±0.022±0.197)x10-5 • Form factor analysis ongoing, results soon Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  23. Parity analysis of pog*g* coupling • f angle of ee plane • dG/df~1+a(cos2f+Csin2f) (SM: a = -0.18, C = 0) • No indication of CP violation KTeV preliminary Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  24. KL->m+m-g • Br(KL->m+m-g)= (3.62±0.04±0.08)x10-7 • Normalized to KL->p+p-po • aK*=-0.160-0.028+0.026 Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  25. KL->e+e-g • Br(KL->e+e-g)= (10.13±0.04±0.06±0.29)x10-6 • Normalized to KL->popopoD • 93383 Sig. / 5306073 Norm. • aK*=-0.192±0.011±0.009(syst) Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  26. Result on aK* Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  27. KL->e+e-m+m- • Normalized to KL->p+p-poD • 93383 Sig. / 5306073 Norm. • Br(KL->e+e-m+m-)= (2.61±0.23±0.18)x10-9 (VMD prediction is 2.34x10-9 ) Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  28. KL->e+e-m+m- • No CP violation effect in angular distribution • Search for lepton flavor violation: • Br(KL->e±e±m±m±)<(4.12)x10-11 (90% C.L., preliminary) • Form factor analysis soon Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  29. Other recent results • KL->p+p-e+e- • 5056 ± 71 events • A=(13.3±1.4±1.0)% (preliminary) • + Vector form factor parameters • KL->pom±e-+ : • Br(KL-> pom±e-+)<(3.34)x10-10 (90% C.L., preliminary) Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

  30. 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… Emmanuel Monnier - C.P.P.Marseille, U. of Chicago BEACH2002

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