The light invisible boson in FCNC decays of B and B_c mesons

Geng Li,Tianhong Wang,Jing-Bo Zhang,Guo-Li Wang

doi:10.1140/epjc/s10052-021-09333-z

Geng Li, Tianhong Wang + Show 2 more

Open Access

https://doi.org/10.1140/epjc/s10052-021-09333-z

Copy DOI

Abstract

In this paper, we study the FCNC decay processes of B and B_c meson, in which one invisible particle is emitted. Both the spin-0 and spin-1 cases are considered. The model-independent effective Lagrangian is introduced to describe the coupling between the light invisible boson and quarks. The constraints of the coupling coefficients are extracted by experimental upper limits of the missing energy in B meson decays. The bounds are used to predict the upper limits of branching fractions of corresponding B_c decays, which are of the order of 10^{-6} or 10^{-5} when final meson is pseudoscalar or vector, respectively. The maximum branch ratios are achieved when m_chi approx 3.5–4 GeV, where m_chi is the mass of the invisible particle.

Highlights

High-energy collider searches might be able to detect dark matter particles produced in collisions through their invisible (“missing”) energy and momentum, which do not match Standard Model (SM) neutrino prediction
As the luminosity of the LHC increases significantly, much more Bc events will be generated in the near future, which provides a new possibility to discover dark matter candidates
We focus on the light invisible bosonic particle which is emitted in flavor-changing neutral current (FCNC) decays of B and Bc meson

Summary

Introduction

High-energy collider searches might be able to detect dark matter particles produced in collisions through their invisible (“missing”) energy and momentum, which do not match SM neutrino prediction This motivates us to study whether DM interactions could help to explain the anomalies. Axion-like dark matter (ALDM) models [41,42,43] usually introduce a general dimension-five Lagrangian which consists of scalar and vector current to describe the coupling between SM fermions and ALDMs. Scalar dark matter candidates can be achieved in minimal extensions of the SM [44,45], in which the hidden scalar can mix with the Higgs boson [46–49]. We focus on the light invisible bosonic particle (both scalar and vector) which is emitted in FCNC decays of B and Bc meson.

Light invisible scalar

Light invisible vector

Conclusion