Decays of B_s Mesons and b Baryons: A Review of Recent First Observations and Branching Fractions

TL;DR

This review summarizes recent experimental observations and measurements of B_s meson and Lambda_b baryon decay modes, including first observations, branching fractions, and implications for Standard Model and beyond.

Contribution

It provides the first observations of six new decay modes of B_s mesons and Lambda_b baryons, along with updated branching fraction measurements from multiple experiments.

Findings

First observations of six new decay modes.

Updated branching fraction measurements and limits.

Implications for electroweak, QCD, and beyond Standard Model physics.

Abstract

Recent rate measurements of B_s mesons and Lambda_b baryons produced in sqrt{s} = 1.96 TeV proton-antiproton and Upsilon(5S) electron-positron collisions are reviewed, including the first observations of six new decay modes: B_s -> D_s^+ K^- (CDF), B_s -> D_s^- D_s^+ (CDF), B_s -> D_{s1}^-(2536) mu^+ nu_mu X (DZero), B_s -> phi gamma (Belle), Lambda_b -> p pi^- (CDF), and Lambda_b -> p K^- (CDF). Also examined are branching-fraction measurements or limits for the B_s -> D_s^{(*)} D_s^{(*)} modes (Belle, CDF, and DZero), the B_s -> gamma gamma radiative penguin decay (Belle), and three two-body charmless B_s meson decay channels (CDF). Implications for the phenomenology of electroweak and QCD physics, as well as searches for physics beyond the Standard Model, are identified where applicable.