New Physics in b -> s Transitions and the B_{d,s}^0 -> V_1 V_2 Angular Analysis

TL;DR

This paper investigates how new physics in b -> s transitions affects angular distributions in B_q^0 -> V_1 V_2 decays, modifies standard-model formulas, and shows that current data can help extract NP parameters.

Contribution

It introduces modified formulas for angular distributions under new physics in b -> s transitions and demonstrates how to extract NP parameters from experimental data.

Findings

Modifications to angular distribution formulas due to NP are significant for B_s decays.

Re-analysis of B_s -> phi phi data shows ~10% changes in observables.

Measurement of untagged distributions can determine all NP parameters.

Abstract

We suppose that there is new physics (NP) in b -> s transitions, and examine its effect on the angular distribution of B_q^0 -> V_1 V_2 (q=d,s), where V_{1,2} are vector mesons. We find that, in the presence of such NP, the formulae relating the parameters of the untagged, time-integrated angular distribution to certain observables (polarization fractions, CP-violating triple-product asymmetries, CP-conserving interference term) must be modified from their standard-model forms. This modification is due in part to a nonzero B^0_q-Bbar^0_q width difference, which is significant only for B^0_s decays. We re-analyze the B^0_s -> phi phi data to see the effect of these modifications. As (Delta Gamma_s/2)/Gamma_s ~ 10%, there are O(10%) changes in the derived observables. These are not large, but may be important given that one is looking for signals of NP. In addition, if the NP contributes to the b -> s decay, the measurement of the untagged time-dependent angular distribution provides enough information to extract all the NP parameters.