The pheno analysis of B K ( ) µ + µ decays in 2011+

Transcription

1 Moriond Electroweak, La Thuile, March 13-20, 2011 The pheno analysis of B K ( ) µ + µ decays in likewise, B s Φµ + µ Gudrun Hiller, Dortmund based on works with Christoph Bobeth and Danny van Dyk Slide 1

2 Exclusive semileptonic FCNC b sµ + µ decays Br SM W ± Y d, s, b b observed (at SM level): u, c, t s b B K ( ) µ + µ BaBar, Belle, CDF X s b g s B s Φµ + µ CDF [hep-ex] B + K + µ + µ LHCb! La Thuile 2011, talk by A.Golutvin; 35 events in 37 pb 1. LHCb: B K µ + µ end of 2011: 1 fb 1 and order 10 3 events; now: order 10 2 events per experiment. Moriond EWK 2011 Slide 2

3 Dilepton Mass Spectra in B K µ+ µ Different TH for low q 2 (QCDF) and high q 2 /low recoil. Binned data needed. Moriond EWK 2011 Slide 3

4 Today: Dilepton Mass Spectra in B K µ + µ dbr/dq db/dq 2 [10-7 /GeV 2 ] J/ψ ψ q 2 [GeV 2 ] black: CDF fb 1, gold: BaBar 08, red: Belle 09; blue: SM; q 2 = m 2 ll Fig. from [hep-ph] Biggest source of TH uncertainty: the B K form factors. Moriond EWK 2011 Slide 4

5 Today: Dilepton Mass Spectra in B K µ + µ Forward-backward asymmetry A FB and longitudinal K fraction F L A FB (q 2 ) J/ψ ψ F L (q 2 ) J/ψ ψ q 2 [GeV 2 ] q 2 [GeV 2 ] black: CDF fb 1, gold: BaBar 08, red: Belle 09; blue: SM; q 2 = m 2 ll Fig. from [hep-ph] Sign of A FB at large dilepton mass is SM-like [hep-ph] Sign/zero of A FB at low dilepton mass? Moriond EWK 2011 Slide 5

6 Model-independent analysis of b sl + l Test the SM and BSM with quantum loop effects using eff theory H eff = 4 G F 2 V tb V ts i C i (µ)o i (µ). Diagrams in SM 4-Fermi-operators: O 9 s L γ µ b L lγ µ l O 10 s L γ µ b L lγ µ γ 5 l Express observables thru Wilson coefficients C 7, C 9, C 10 and extract the latter from data. Dipole coupling C 7 fixed by Br(B X s γ). Moriond EWK 2011 Slide 6

7 C 9 -C 10 Scans B K l + l pre 2010 global fits to (real) C 9, C 10 for C 7 = ±C SM 7 ; green box: SM value for (C 9, C 10 ) EOS project: Fig. from [hep-ph] agreement with SM; order 1 BSM allowed. Moriond EWK 2011 Slide 7

8 C 9 -C 10 Scans B K l + l 2010 Including low recoil data global fits to (real) C 9, C 10 for C 7 = ±C7 SM ; green box: SM value for (C 9, C 10 ) EOS project: Bobeth, GH,vanDyk [hep-ph] agreement with SM; order 1 BSM allowed. Gives Br(B s µ + µ ) within [ , ] (2σ) : IFF A FB has zero, only 2 solutions with C i = ±C SM i remain. Moriond EWK 2011 Slide 8

9 Exploiting B K l + l at low recoil further OPE in 1/Q, Q = {m b, q 2 } by Grinstein, Pirjol 04 with heavy quark FF relations T 1,2,3 V, A 1,2 leads to simply transversity structure with universal short-distance C and form factor coefficients f i A i C f i, i = 0,,, up to corrections of order α s Λ/m b and (C 7 /C 9 )Λ/m b (few percent). Allows to design new observables which are Bobeth, GH,vanDyk , and 11 independent of form factors (H (2,3) T ) independent of short-distance coefficients and test the form factors independent of either ones and test the theoretical low recoil framework H (1) T, H(2) T /H(3) T Moriond EWK 2011 Slide 9

10 Exploiting B K l + l at low recoil further Low recoil HQ-OPE: H (1) T = 1, H (2) T /H(3) T = 1. Extract them from the B K ( Kπ)µ + µ angular distribution. Moriond EWK 2011 Slide 10

11 Full Angular Analysis in B V ( P P )µ + µ on-shell decaying V : dγ 4 Jdq 2 d cos Θ l d cos Θ K dφ hep-ph/ J i = J i (q 2 ) are functions of transversity amplitudes. Θ l : angle between l and B in dilepton CMS (warning: different conventions in literature) Θ K : angle between K and B in K -CMS Φ: angle between normals of the Kπ and l + l plane Γ J 1 J 2 /3, A FB J 6, A (2) T J 3 hep-ph/ , S 5 J [hep-ph] Moriond EWK 2011 Slide 11

12 Full Angular Analysis in B V ( P P )µ + µ Several [hep-ph] groups working on angular analyses recently , , , , , , , , and counting... CP-asymmetries from angular distribution A i J i J i : SM: all doubly Cabbibo-suppressed and null tests of the SM. A 3, A 9 vanish in SM by helicity conservation: sens. to RH currents A 3, A 9, (A 6 ) can be extracted from single-diff distribution in Φ(Θ l ) A 7,8,9 T-odd: not suppressed by small strong phases; O(1) with BSM A 5,6,8,9 CP-odd: can be extracted without tagging from Γ + Γ; advantageous for B s, B s (Φ K + K )µ + µ. Moriond EWK 2011 Slide 12

13 T-odd versus T-even CP Asymmetries A 7, A 8, A 9 are T-odd and can be order one with BSM. Tab. from Moriond EWK 2011 Slide 13

14 Summary It is fantastic to witness great advances in FCNC b-decays and respective tests of SM and BSM physics. After observing exclusive b sll modes, first results of basic decay distributions and asymmetries are now available by several experiments. More involved and designed ones are accessible by angular analysis, promising for LHCb and Tevatron with muons; opportunity for electrons and neutrinos, also inclusive modes and if feasible taus, for super flavor factory. Lots of recent TH focus on angular distribution and their exploitation. Moriond EWK 2011 Slide 14

15 Summary New developments at low hadronic recoil in theory pheno+lattice greatly support exploitation of todays and tomorrows data. E.g., recent OPE study by Beylich et al [hep-ph]; Preliminary unquenched lattice B K ( ) form factors by Liu et al [hep-ph]. The large number of complementary observables accessible with b s decays allows us to map out precisely the amount of CP violation, or BSM phenomena such as right-handed currents, or large scalar currents present at the TeV-scale. Analysis workshop on b sll at low recoil at DESY Hamburg June 15-17, 2011; please send if you want to contribute. Moriond EWK 2011 Slide 15