Reducing Penguin Pollution

Abstract

The most common decay used for measuring 2beta_s, the phase of Bs-Bsbar mixing, is Bs -> J/psi phi. This decay is dominated by the colour-suppressed tree diagram, but there are other contributions due to gluonic and electroweak penguin diagrams. These are often referred to as "penguin pollution" (PP) because their inclusion in the amplitude leads to a theoretical error in the extraction of 2beta_s from the data. In the standard model (SM), it is estimated that the PP is negligible, but there is some uncertainty as to its exact size. Now, phi_s^{c\bar{c}s} (the measured value of 2beta_s) is small, in agreement with the SM, but still has significant experimental errors. When these are reduced, if one hopes to be able to see clear evidence of new physics (NP), it is crucial to have the theoretical error under control. In this paper, we show that, using a modification of the angular analysis currently used to measure phi_s^{c\bar{c}s} in Bs -> J/psi phi, one can reduce the theoretical error due to PP. Theoretical input is still required, but it is much more modest than entirely neglecting the PP. If phi_s^{c\bar{c}s} differs from the SM prediction, this points to NP in the mixing. There is also enough information to test for NP in the decay. This method can be applied to all Bs/Bsbar -> V1 V2 decays.

17 pages, latex, extensive discussion of theoretical error added, reference added. Further revision: even more detailed discussion of theoretical error added, as well as an explanation of why the NP strong phase is negligible

References in corpus (7)

• Anatomy of New Physics in B-Bbar mixing
• Measurement of the CP-violating phase phi_s in the decay Bs->J/psi phi
• Precision Physics with B^0_s -> J/psi phi at the LHC: The Quest for New Physics
• B_s to K^(*)0 \bar K^(*)0 decays: the golden channels for new physics searches
• Doubly CKM-suppressed corrections to CP asymmetries in $B^0\to J/\psi K^0$
• New Physics in b -> s Transitions and the B_{d,s}^0 -> V_1 V_2 Angular Analysis
• Measuring beta_s with Bs -> K0(*) K0bar(*) -- a Reappraisal

Cited by in corpus (8)

• Isospin asymmetries in $B\to (K^{\ast },\rho )\gamma /l^{+}{l}^{-}$ and $B\to K{l}^{+}{l}^{-}$ in and beyond the Standard Model
• Measurement of the CP-violating weak phase phi[s] and the decay width difference Delta Gamma[s] using the Bs to J/Psi phi(1020) decay channel in pp collisions at sqrt(s) = 8 TeV
• Penguin Pollution in $B\to J/\psi V$ Decays and Impact on the Extraction of the $B_s-{\bar{B}}_s$ mixing phase
• Searching for New Physics with bbar -> sbar Bs -> V_1 V_2 Penguin Decays
• Recent Developments on the CKM Matrix
• Quantisation of Klein-Gordon field in $\kappa$ space-time: deformed oscillators and Unruh effect
• Probing quantum decoherence at Belle II and LHCb
• Constraining new physics in B_s meson mixing