Revealing new physics in decays

Robert Fleischer; Eleftheria Malami

doi:10.1140/epjc/s10052-023-11588-7

2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2023) 83: 420
https://doi.org/10.1140/epjc/s10052-023-11588-7

Regular Article - Theoretical Physics

Revealing new physics in $B_{s}^{0} \to D_{s}^{\mp} K^{\pm}$ ${\varvec{B}}^{0}_{s}\rightarrow D_s^{\mp } K^{\pm }$ decays

Robert Fleischer¹^,2 and Eleftheria Malami¹^b

¹ Nikhef, Science Park 105, 1098 XG, Amsterdam, The Netherlands
² Department of Physics and Astronomy, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands

^b emalami@nikhef.nl

Received: 4 November 2022
Accepted: 4 May 2023
Published online: 19 May 2023

Abstract

The $B_{s}^{0} \to D_{s}^{\mp} K^{\pm}$ $B^0_s\rightarrow D_s^{\mp } K^{\pm }$ system offers a determination of the Unitarity Triangle angle $γ$ $\gamma$ . Intrigued by an LHCb analysis showing a surprisingly large result in tension with information on the Unitarity Triangle and other $γ$ $\gamma$ measurements, we make a transparent study of the measured observables, confirming the LHCb picture. The corresponding $γ$ $\gamma$ puzzle at the $3 σ$ $3\sigma$ level would require CP-violating contributions of New Physics, which should also manifest themselves in the corresponding decay branching ratios. Indeed, we find that the rates of the individual $B_{s}^{0} \to D_{s}^{\mp} K^{\pm}$ $B^0_s\rightarrow D_s^{\mp } K^{\pm }$ channels show puzzling patterns, in accordance with similar decays, with tensions up to $4.8 σ$ $4.8\sigma$ , thereby making the situation much more exciting. We present a formalism to include New-Physics effects in a model-independent way and apply it to the data to constrain the corresponding parameters. Interestingly, new contributions of moderate size could accommodate the data. Utilising this formalism in the future high-precision B physics era may allow us to finally establish new sources of CP violation.

© The Author(s) 2023

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