A Consistent Resolution of Possible Anomalies in B 0 → φK S and B + → η ′ K + Decays

In the framework of R-parity violating (Rp / ) supersymmetry, we try to find a consistent explanation for both recently measured CP asymmetry in B0 → φKS decay and the large branching ratio of B → ηK decay, which are inconsistent with the Standard Model (SM) prediction. We also investigate other charmless hadronic B → PP and B → V P decay modes whose experimental data favor the SM: for instance, recently measured CP asymmetries in B0 → ηKS and B0 → J/ΨKS . We find that all the observed data can be accommodated for certain values of Rp / couplings. [email protected] [email protected], http://phya.yonsei.ac.kr/ ̃cskim/ [email protected] 1 The main mission of B factories, such as KEK−B and SLAC−B, is to test the Standard Model (SM) and further to find possible new physics effects in B meson systems. For this goal, a variety of useful observables can be measured to be compared with theoretical expectations. One of the important observables is CP asymmetries in various B meson decays, and another is branching ratios (BRs) for rare B decay processes. CP violation in B system has been confirmed in measurements of time-dependent CP asymmetries in B → J/ΨKS decay. The world average of the asymmetry in B → J/ΨKS [1] is given by sin(2β)J/ΨKS = 0.734± 0.054 , (1) which is consistent with the SM expectation. However, recent measurements of sin(2β) in B → φKS decay disagree with the above value. The measurements of time-dependent CP asymmetries in B → φKS have been recently reported by BaBar [2] and Belle [3], respectively: sin(2β) φKS = −0.19 +0.52 −0.50 ± 0.09 , (2) sin(2β) φKS = −0.73± 0.64± 0.18 . (3) Both experimental results show (a tendency of) negative values of sin(2β). Because within the SM the difference between the asymmetries in B → J/ΨKS and B → φKS is expected to be [4] | sin(2β)J/ΨKS − sin(2β)φKS | < ∼ O(λ) (4) with λ ≈ 0.2, these results indicate 2.7 σ deviation from the SM prediction and may reveal new physics effects. The decay process B → φKS is a pure penguin process b → ss̄s, and in the SM the time-dependent CP asymmetry of this mode is expected to measure the same sin(2β) as in B → J/ΨKS, as shown in Eq. (4). If there are any new physics effects in the measurements of time-dependent CP asymmetries, the effects can arise from new contributions to the 2 B − B̄ mixing amplitude and/or the decay amplitude of each mode. Because the new physics effects to the B0− B̄ mixing would be universal to all the neutral B d meson decays, the discrepancy between the measured values of sin(2β)J/ΨKS and sin(2β)φKS may indicate the possibility of new physics effects in the decay amplitude of B → φKS. Supposing that the mode B → φKS reveals new physics effects [4,5], one might expect that other modes having the same internal quark level process b → ss̄s (e.g., B → ηKS) would reveal the similar effects. Interestingly, the recent measurements of CP asymmetries in B → ηKS by Belle [3] agree well with the results of sin(2β)J/ΨKS given in Eq. (1) (see Table I). Therefore, any successful explanation invoking new physics should accommodate the data disfavoring the SM, such as sin(2β)φKS , and simultaneously all the data favoring the SM, such as sin(2β)η′KS and sin(2β)J/ΨKS . Motivated by the recent measurements of sin(2β)φKS , a few first analyses [1,6–9] have been done. But, all of them explain only the deviation of sin(2β)φKS from the SM prediction, or in addition, make (at most) qualitative statements on sin(2β)η′KS [1,6–9]. There also exist plenty of experimental data observed for charmless hadronic B → PP (P denotes a pseudoscalar meson) and B → V P (V denotes a vector meson) decay modes, which are well understood within the SM. However, among the B → PP decay modes, the BR of the decay mode B → ηK is found to be still larger than that expected within the SM [10–13]: the experimental world average is B(B± → ηK) = (75 ± 7) × 10. The SM contribution is about 3σ smaller than the experimental world average [13]. Among the B → V P decay modes, the experimentally observed BR for the decay B → ηK has been also found to be 2σ larger than the SM expectation [13]. In this letter we try to find a consistent explanation for all the observed data in charmless hadronic B → PP and B → V P decays in the framework of R-parity violating (Rp / ) 1Attempts to explain the large B(B± → ηK) within the SM have been made: e.g., by using the anomalous g − g − η coupling [14].