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Chuan-Hung Chen

Lepton flavor violation in Tau decays. Chuan-Hung Chen. Department of Physics, National Cheng-Kung U., Tainan, Taiwan. seminar@cycu.11.21.06.tw. Introduction & Motivation. Higgs-mediated LFV. Implications of LFV in tau decays. Speculation of Higgs-mediated effects.

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Chuan-Hung Chen

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  1. Lepton flavor violation in Tau decays Chuan-Hung Chen Department of Physics, National Cheng-Kung U., Tainan, Taiwan seminar@cycu.11.21.06.tw Introduction & Motivation Higgs-mediated LFV Implications of LFV in tau decays Speculation of Higgs-mediated effects

  2. Introduction & Motivation What we can learn from B factories: • CP violations: time-dependence CP asymmetry & direct CP violation ICHEP2006: 1 with bs Penguins

  3. Test QCD theories: PQCD, QCDF, final state interactions etc. • Determine the parameters of CKM matrix elements, or fB

  4. Probe flavor structures:

  5. B-factory: 1 ×109 t Super-B: 100 ×109 t CLEO-c: 10 ×106 t BES-III: 100 ×106t Future tau () physics

  6. results up to 2005

  7. Lepton flavor violation (LFV) • quark flavor changing via charged current; charged weak current is written as In terms of physical eigenstates By Wolfenstein parametrization

  8. In the standard model (SM), the flavor changing neutral currents (FCNCs) arise from loop • Rear decays induced from loop will be sensitive to new physics. • In the SM, since neutrinos are massless, there are no flavor violations in lepton sector • According to observed neutrino oscillations, we know that neutrinos have masses so that Maki-Nakagawa-Suzuki-Pontecorvo (MNSP)

  9. Higgs-mediated LFV • Nonzero neutrino masses are definite. • It is found that seesaw mechanism, by introducing singlet right-handed Majorana neutrinos, is one of natural ways to solve the tiny neutrino masses which are less than a few eV. • In non-SUSY models, the effects of LFV are suppressed by 1/MR which is around GUTs scale 1015 GeV. • However, in models with SUSY, due to the right-handed Majorana introduced, the flavor conservation in the slepton sector at unified scale will be violated at the MR scale via renormalization. Borzumati, Masiero, PRL57,961; Hall, Rattazzi, Sarid, PRD50,7048;Babu, Kolda, PRL89,241802

  10. Babu & Kolda’s mechanism for lepton flavor violation nonholomophic terms

  11. At large tan ~ mt/mb, or cos << 1, the Higgs-mediated LFV will be enhanced

  12. Implications of LFV in  decays   (, 3, , KK) induced by slepton mixings with large tan Due to slepton mixings

  13. Due to nonholomophic effects, is not diagonal matrix LFV with Higgs-mediated nonholomophic terms Y: diagonalized Yukawa matrix of leptons • Since 2 are loop effects, they are much less than 1, the LFV can be regarded as a leading expansion of 2Iij

  14. Employ the physical mass eigenstates of the Higgses • The interactions for the LFV via the Higgs-mediated mechanism • are expressed by

  15. Since the LFVs in and decay are driving by the same mechanism, to simplify the discussions, we take M1~M2~m0~~    • MU ~ 1019 GeV , MR ~ 1014 GeV • tan=60 • BR< (3.1, 0.68)  107

  16. s  A , ’  s • =39.30 • fs=0.17 GeV • mss=0.69 GeV

  17.  s h, H  s •  = 300, • ms = 0.15 GeV, • decoupling limit:  /2

  18.  A h, H   • cs: cos(-)sin  ; sc=sin(-)cos • decoupling limit:  /2

  19.  K h, H  K • v=2.87 GeV, =-10.4 GeV4 Cheng,Chua, Soni, PRD72,094003

  20. Speculation of Higgs-mediated effects • In terms of squark mixings, Babu,Kolda, PRL84,228(00)

  21. It is interesting to examine the effects on B decays • Charged Higgs on B • Higgs-mediated on • Higgs-mediated on • Higgs-mediated on

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