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Charmless Two-Body B Decays Involving a Tensor Meson Kwei-Chou Yang Chung-Yuan Christian University, Taiwan The 36th International Conference on High Energy Physics (ICHEP2012) in collaboration with Hai-Yang Cheng
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Polarization puzzles in ---- SM or New-Physics B decays involving a tensor meson ----further test: SM or New-Physics Conclusion Outline
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3 Introduction Polarization puzzle in charmless B→VV decays Why is f T sizable ~ 0.5 in B → K * φ decays ? In transversity basis Search of new physics in B→VV decays ?
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4 Parametrization Explanation within the SM: Annihilation In SM, the Annihilation effect is important:
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5 B → K * without annihilation) 3 =a 3 +a 5, 4 =a 4 -r a 6, 3,EW =a 9 +a 7, 3 = penguin ann h=0 h= - h=0 h= - Coefficients are helicity dependent ! constructive (destructive) interference in A - (A 0 ) ⇒ f L ~ 0.58 with 3 =0 NLO corrections alone will bring down f L significantly ! Br ~4.3*10 -6 (without annihilation), too small compared with data PRD,2008, Hai-Yang Cheng, KCY
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6 Although f L is reduced to 60% level, polarization puzzle is not resolved as the predicted rate, BR~ 4.3*10 -6, is too small compared to the data, ~ 10*10 -6 for B →K * penguin annihilation f || ≒ f ⊥ ≒ 0.25
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7 constructive destructive constructive ⇒ f L (K *- 0 )=0.96, f L (K *0 0 )=0.47 (=0.91 if a i h are helicity indep) But, the predicted rates for K *- 0 & K *0 0 are too small ! with 3 =0 Without Annihilation
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8 Process dependent
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9 Tree-dominated VV modes Longitudinal amplitude dominates tree-dominated decays except for 0 Predicted B → ω rates agree with the data. H.Y. Cheng & KCY, PRD, 2008 vs. data (2010)
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10 Scenario with New Physics
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Possible New Physics 11 Phys. Rev. D71, 094002 (2005), KCY& Das See also works by Alex Kagan; C.S. Kim, Y.D. Yang;
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13 Two-body B decays involving a tensor meson
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14 Light-cone distribution amplitudes for a tensor meson chiral-even PRD82:054019,2010, H.Y. Cheng,Y. Koike, KCY twist-2: ∥, twist-3: g v, g a, h t, h s twist-4: g 3, h 3 Asymptotic form of chiral-even DAs is first studied by Braun & Kivel (‘01) chiral-odd
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15 twist-2: ∥, twist-3: g (v),g (a), h (t), h ∥ (p) related to twist-2 ones via Wandzura-Wilczek relations (neglecting 3-parton distributions) 3 P 2 tensor meson Due to G-parity, , h ∥ (t), h ∥ (p), ∥,g (v), g (a) are antisymmetric with the replacement u → 1-u in SU(3) limit C i 3/2 : Gegenbauer polynomial
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16 Decay constants Tensor meson cannot be produced from local V-A current owing to p =0 Can be created from local current involving covariant derivatives with Previous estimates: Aliev & Shifman (’82); Aliev, Azizi, Bashiry (’10) Based on QCD sum rules we obtain (Cheng, Koike, KCY, arXiv:1007.3526) Normalized with
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17 VT modes Data from BaBar Naïve factorization, Kim,Lee & Oh, PRD (2003); Munoz,Quintero, J.Phys.G (2009) QCD factorization (without annihilation) too small Within SM, to account for data, penguin annihilation is necessary PRD83:034001,2011, Hai-Yang Cheng, KCY
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18 To account for data, penguin annihilation is necessary Process-dependent ? Ann is dominant for
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19 Polarization puzzle in B K 2 * f L (K 2 *+ ) = 0.56 0.11, f L (K 2 *0 ) = 0.45 0.12, f L (K 2 *+ ) = 0.80 0.10, f L (K 2 *0 ) = 0.901 +0.059 -0.069 f L (K 2 * ) = 0.88, 0.72, 0.48 for A TV = -30 o, -45 o, -60 o, f L (K 2 * )= 0.68, 0.66, 0.64 for A VT = -30 o, -45 o, -60 o In QCDF, f L is very sensitive to the phase A TV for B K 2 * , but not so sensitive to A VT for B K 2 * Why is f T / f L <<1 for B K 2 * and f T /f L 1 for B K 2 * ? Rates & polarization fractions can be accommodated in QCDF BaBar but no dynamical explanation is offered Why is that f T behaves differently in K 2 * and K * ? Fine-tuning!
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20 Further test Sizable BR
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21 New Physics due to tensor currents Relatively smaller B K * B K 2 * Larger f L compared with K*
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22 Conclusions New physics solutions: the only candidates are the tensor operators (Pure (S ± P)(S ± P) operators are unlikely) Further information ( b → s s s) can be extracted from and some other modes involving the tensor meson
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23 (pseudo-)scalar-type operators tensor-type operators
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24 Can only (pseudo-)scalar-type operators explain the data? Answer: NO In the minimal supersymmetric standard model (MSSM), such scalar/pseudoscalar operators can be induced by the penguin diagrams of neutral-Higgs bosons. A combined analysis of the decays shows that the NP effects only due to (pseudo-)scalar-type operators is much smaller in B →K * modes. and to be consistent with the data for PRD77, 035013 (2008), H. Hatanaka, KCY
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25 Penguin-dominated B TP
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26 B - K 2 *0 vanishes in naïve factorization, while its BR is measured to be ~ 5.6 10 -6 importance of nonfactorizble effects Penguin annihilation is needed in QCDF to account for rates & CP asymmetries TP =0.83, TP = -70 o PT =0.75, PT = -30 o similar to the parameters for B PP
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