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Introduction

Introduction. In the Standard Model, the FCNC decay of B  m + m - is heavily suppressed. SM prediction . (Buchalla & Buras, Misiak & Urban). Bd  mm is further suppressed by CKM couping (v td /v ts ) 2. SM prediction is below the sensitivity of current experiments

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Introduction

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  1. Introduction • In the Standard Model, the FCNC decay of B m+m- is heavily • suppressed SM prediction  (Buchalla & Buras, Misiak & Urban) • Bdmm is further suppressed by CKM couping (vtd/vts)2 • SM prediction is below the sensitivity of current experiments • (CDF+D0): SM  Expect to see 0 events at the Tevatron • Any signal would indicate new physics!! Cheng-Ju Lin Fermilab Wine&Cheese

  2. BEYOND STANDARD MODEL • In many SUSY models, the BR could be enhanced by many • orders of magnitude: • For example: • - MSSM: Br(Bmm) is • proportional to tan6b • - Br(B mm) also • enhanced at high tanb in • GUT SO(10) models • - BR could be as large as • 10-1000 times the SM prediction Would be observable at the Tevatron Cheng-Ju Lin Fermilab Wine&Cheese

  3. BEYOND STANDARD MODEL • Another example: • R-Parity violating SUSY • - Tree level diagram is allowed in • R-parity violating (RPV) SUSY • models. • - Possible to observe decay • even for low value of tanb • - Enhancement depends strongly • on coupling constants (l , l’) R-parity violating SUSY m b ~ n l’i23 l i22 m s Would also be observable at the Tevatron Cheng-Ju Lin Fermilab Wine&Cheese

  4. PROBE OF NEW PHYSICS Monte Carlo • New physics may enhance Bs and • Bdmm differently • Minimal-flavor-violation (MFV) • assumption in SUSY yields SM • relations between Bs and Bdmm • decays • Can observe both Bs and Bd: unique to • Tevatron • CDF has the mass resolution to • distinguish two decays, s(Mmm)~23MeV : • unique to CDF • Either observation or null search, results will provide important • clues about possible scenarios of new physics beyond SM M(Bs)-M(Bd)~90MeV

  5. Limits Summary Bs: we observed 0 events which yields a combined limit of: 1.6×10-7 @ 90% CL 2.1×10-7 @ 95% CL Bd: we observed 0 events which yields a combined limit of: 3.9×10-8 @ 90% CL 5.1×10-8 @ 95% CL Br(Bsmm) < 4.1×10-7 @ 90% CL ; D0 PRL 94 (2005) 042001 Br(Bsmm) < 5.8×10-7 @ 90% CL ; CDF PRL 93 (2003) 032001 Br(Bdmm) < 3.0×10-7 @ 90% CL ; D0 Preliminary 4733 Br(Bdmm) < 8.0×10-8 @ 90% CL ; (BaBar PRL 94 (2005) 221803 Both CDF Bs and Bd results are x2 better than the best published result!!!

  6. B. Dutta, U. Regina m b R-parity violating SUSY ~ n l’i23 l i22 m s RPV SUSY EXCLUSION • Possible to exclude phase space • even for small tan(b) • Exclusion strongly depends on the • coupling. Excluded

  7. Dedes, Dreiner, Nierste, PRL 87(2001) 251804 mSUGRA M0 vs M1/2 Excluded • We are beginning to carve • into mSUGRA space • For mh~115GeV implies • 10-8<Br(Bsmm)<3×10-7 M0 [GeV] Excluded Solid red = excluded by theory or experiment Dashed red line = light Higgs mass (mh) Dashed green line = (dam)susy (in units of 10-10) Black line = Br(Bsmm)

  8. Dedes, Dreiner, Nierste, PRL 87(2001) 251804 mSUGRA M0 vs M1/2 Excluded • We are beginning to carve • into mSUGRA space • For mh~115GeV implies • 10-8<Br(Bsmm)<3×10-7 M0 [GeV] Excluded by this new result Excluded Solid red = excluded by theory or experiment Dashed red line = light Higgs mass (mh) Dashed green line = (dam)susy (in units of 10-10) Black line = Br(Bsmm)

  9. SO(10) Unification Model R. Dermisek et al., hep-ph/0304101 • tan(b)~50 constrained by • unification of Yukawa coupling • White region is not excluded • Unification valid for small M1/2 • (~500GeV) h2>0.13 mh<111GeV m+<104GeV Red regions are excluded by either theory or experiments Green region is the WMAP preferred region Blue dashed line is the Br(Bsmm) contour Light blue region excluded by old Bsmm analysis

  10. SO(10) Unification Model R. Dermisek et al., hep-ph/0304101 • tan(b)~50 constrained by unification • of Yukawa coupling • All previously allowed regions (white) • are excluded by this new measurement • Unification valid for small M1/2 • (~500GeV) • New Br(Bsmm) limit strongly • disfavors this solution for • mA= 500 GeV h2>0.13 mh<111GeV m+<104GeV Excluded by this new result Red regions are excluded by either theory or experiments Green region is the WMAP preferred region Blue dashed line is the Br(Bsmm) contour Light blue region excluded by old Bsmm analysis

  11. BsLimit Projection • Extrapolate based on the • current analysis which was • optimized for 1/fb • Assume background scales • linearly with luminosity • Will need to re-optimize the • analysis for > 3/fb Cheng-Ju Lin Fermilab Wine&Cheese

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