Search for New Physics Signals via Doubly Weak B Decays

TL;DR

This paper investigates rare doubly weak B decays as potential signals of new physics, analyzing model-independent effects and specific Randall-Sundrum models, predicting significant enhancements in decay rates that could be observed experimentally.

Contribution

It provides a model-independent analysis of doubly weak B decays within perturbative QCD and explores effects in Randall-Sundrum models, predicting observable enhancements.

Findings

Large effects possible in effective operators

Significant branching ratio enhancements in models

Predictions for future experimental searches

Abstract

The doubly weak $b\to dd{\bar s}$ and $b\to ss{\bar d}$ processes are highly suppressed in the standard model that offer the unique opportunity to explore new physics signals. The wrong sign decay $\smash{\overline B}^0\to K^+\pi^-$ mediated by the $b\to dd{\bar s}$ transition can be distinguished from the penguin decay $\smash{B}^0\to K^+\pi^-$, through time dependent measurement in experiments. We consider a model independent analysis of $\smash{\overline B}^0\to K^+\pi^-$ decay, within the perturbative QCD approach and explore various effective dimension-6 operators, in which large effects are possible. We also study the doubly weak exclusive process in two example models namely Randall-Sundrum model with custodial protection and the bulk-Higgs Randall-Sundrum model. A large and significant enhancement of the branching ratio, in comparison to the standard model, is observed after satisfying all the relevant constraints on the parameter spaces of these models, which requires to be searched in future experiments.