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B Decays Beyond the Standard Model

B Decays Beyond the Standard Model. Xiao-Gang He NTU Introduction B to K pi and pi pi B to phi Ks and B to K* gamma decays Same sign diplepton decays in B–barB mixing Discussions. Introduction “Rare B decays are good probes of new physics beyond

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B Decays Beyond the Standard Model

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  1. B Decays Beyond the Standard Model Xiao-Gang He NTU • Introduction • B to K pi and pi pi • B to phi Ks and B to K* gamma decays • Same sign diplepton decays in B–barB mixing • Discussions

  2. Introduction “Rare B decays are good probes of new physics beyond the Standard Model.” Is there any confirmed experiments need new physics beyond the minimal Standard Model? Yes, but not in B decays.  Neutrino Oscillations! What is the situation in B decays? There are some indications. Time dependent. Why then new physics?

  3. [hep-ex/0408072] [hep-ex/0409049] _ 227M BB _ 275M BB CP violation in B to phi Ks “sin2f1” = +0.500.25 A = 0.00 0.23 0.05 “sin2f1” = +0.06 0.33 0.09 A = +0.08 0.22 0.09 Not confirmed. Need More Data

  4. It is wrong to average different modes which have different sources of contaminations.

  5. B to pi pi and K pi There are deviations from both QCDF and pQCD compared with data. But large hadronic uncertainties prevent clear statements about new physics. However, new physics cannot be ruled out.

  6. B to Xs gamma, K* gamma

  7. There are many other processes also show deviations from theoretical calculations, polarization in B to phi K*…. All need to be further confirmed from experiments. There are large theoretical uncertainties in the SM for some processes, such as B to K pi, pipi, and polarization in B to phi K*. Difficult to make clear cut statements about NP. But then try to see if NP can improve the situation and take them as evidences. There are certain processes for which SM predictions are “free” from hadronic uncertainties, such as B to Xs gamma, CP in B to K* gamma and B to phi Ks. Good probes for NP. Recently Belle has also tried to measure the same sign dilepton decays in B—barB Mixing with Also a good probe for new physics. What NP? There are many models, needs new physics in the flavor sector. Take SUSY as illustration.

  8. Flavor changing interaction in the SM

  9. c1=1.081, c2=-0.190, c3=0.014, c4=-0.036, c5=0.009, c6=-0.042c7=-0.011/137, c8=0.060/137, c9=-1.254/137, c10=0.223/137c11=-0.151, c12=-0.318

  10. SUSY gluonic dipole interaction ratio of gluino mass to squark masse C11,12= C(susy), C’11,12 change delta(LR) to delta(RL)

  11. Neglect small contributions from c7 and c8 (He and McKellar, hep-ph/0410098) 2. B to K pi and pi pi

  12. With 4 K pi branching ratios and CP in K- pi+ P = 1, Solutions Fit all K pi data chi-square-minimal 5 With 3 pi pi branching ratios and CP A, S in pi+pi- Solutions

  13. Fit withK pi, pi pibranching ratios and CP in K-pi+ chi-square-minmal 8 Fit with all data chi-squae-minmal 22

  14. QCDF and pQCD cannot account for data in B to K pi , pipi. Improvements needed. • Problem with SU(3) ? SU(3) breaking… • Problem with data? Need improved data • New physics? Tree? (R-parity violation…) Strong penguin? (SUSY, Left-Right model…) Electroweak penguin (SUSY, Left-Right mode…)

  15. SUSY gluonic dipole contributions to B to K pi(He, Li and Yang, hep-ph/0409338)

  16. Constraints from B to Xs gamma on SUSY parameters (He, Li and Yang, hep-ph/0409338)

  17. 3. B to phi Ks and B to K* gamma Time dependent CP violation in these decays are very good probes for NP beyond the SM.

  18. In the Standard ModelS(J/psi Ks) => sin(2beta) = 0.726S(phi Ks) => sin(2beta)

  19. SUSY gluonic dipole contributions to B to phi Ks Barbar Belle(He, Li and Yang, hep-ph/0409338)

  20. B to K* gamma to Ks pi0 gamma

  21. Babar Belle

  22. 4. Same sign dilepton decays in B-barB (Sanda)

  23. 5. Discussions and conclusions • There is no immediate needs of New Physics from current B decay data. But can constrain NP. • There are some indications in B to K pi, pi pi decays, (and other hadronic decays). There are large hadronic uncertainties to make clear cut sttaements about NP. Need further improvement both in theoretical calculations in the SM and data. But NP can improve the agreements of theoretical results with data. • There are many B decays where hadronic uncertainties can be eliminated, such as CP violations in B to phi Ks, K* gamma, and same sign dilepton decays in B-barB mixing. NP can change the SM predictions. Good probeds for NP. • More data are coming. A bright future ahead. Many models beyond SM need to be examined, such as susy, R-parity violating susy, left-right, little higgs, ... Models.

  24. 谢谢!

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