Searching new physics in rare B-meson decays into multiple muons

Mikael Chala,Michael Spannowsky,Ulrik Egede

doi:10.1140/epjc/s10052-019-6946-6

Mikael Chala, Michael Spannowsky + Show 1 more

Open Access

https://doi.org/10.1140/epjc/s10052-019-6946-6

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Abstract

New heavy vector bosons and light scalars are predicted in a plethora of models of new physics. In particular, in new strongly interacting sectors they play the role of the rho and pi mesons in QCD. We show that some of their interactions, for example those required for the explanation of the B anomalies and the g-2 of the muon, can be only probed in B meson decays. We highlight new golden channels not yet studied experimentally, including B^+ rightarrow K^+(D^+)mu ^+mu ^-mu ^+mu ^- and B^0rightarrow K^{*0}mu ^+mu ^-mu ^+mu ^-. Relying on generator level simulations for data taking with the LHCb detector, we determine the reach of this facility to the aforementioned processes. We show that branching ratios as small as 9times 10^{-12} (3.2times 10^{-10}) and 2.7times 10^{-11} can be tested at the 95% CL respectively.

Highlights

Let us extend the SM with a new vector boson V and a new scalar a with masses of the order of TeV and GeV, respectively
We have considered scenarios involving new heavy and flavour-violating vectors V as well as light scalars a
We have shown that these particles give rise to rare B meson decays that are not yet probed

Summary

Generic Lagrangian

Let us extend the SM with a new vector boson V and a new scalar a with masses of the order of TeV and GeV, respectively. They are both singlets of the SM gauge group. Similar expressions hold for other processes, e.g. B0 → K ∗0aa or Bc+ → D+aa The latter is hard to test at the LHCb and we will not consider it. We will assume that a decays into muons with a width smaller than ∼ 10 MeV and a lifetime shorter than ∼ 10 fs In this case, it will appear not to have any experimentally measurable flight distance and will appear to have zero width. Muon final states with and without additional mesons and with the muons forming pairs of two identical masses

Explicit model

Reach of the LHCb

Conclusions