# Novel $B$-decay signatures of light scalars at high energy facilities

## TL;DR

This paper explores new light scalar decay signatures in B mesons at high-energy colliders, proposing novel experimental analyses at LHCb to detect these rare processes and outperform existing constraints.

## Contribution

It introduces new B decay channels involving light scalars and proposes experimental strategies at LHCb to search for these signals, extending the reach beyond current bounds.

## Key findings

- LHCb can probe branching ratios as low as 6.0×10^{-9} for certain channels
- Proposed analyses can test scalar masses below a few GeV
- Searches outperform existing meson mixing constraints

## Abstract

We study the phenomenology of light scalars of masses $m_1$ and $m_2$ coupling to heavy flavour-violating vector bosons of mass $m_V$. For $m_{1,2}\lesssim $ few GeV, this scenario triggers the rare $B$ meson decays $B_s^0\to 3\mu^+ 3\mu^-$, $B^0\to 3\mu^+ 3\mu^-$, $B^+\to K^+ 3\mu^+ 3\mu^-$ and $B_s^0\to K^{0*} 3\mu^+ 3\mu^-$; the last two being the most important ones for $m_1\sim m_2$. None of these signals has been studied experimentally; therefore we propose analyses to test these channels at the LHCb. We demonstrate that the reach of this facility extends to branching ratios as small as $6.0\times 10^{-9}$, $1.6\times 10^{-9}$, $5.9\times 10^{-9}$ and $1.8\times 10^{-8}$ for the aforementioned channels, respectively. For $m_{1,2}\gg \mathcal{O}(1)$ GeV, we show that slightly modified versions of current multilepton and multitau searches at the LHC can probe wide regions of the parameter space of this scenario. Altogether, the potential of the searches we propose outperform other constraints such as those from meson mixing.