Heavy + light pseudoscalar meson semileptonic transitions

Zhen-Ni Xu; Zhu-Fang Cui; Craig D. Roberts; Chang Xu

doi:10.1140/epjc/s10052-021-09898-9

EPJ

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2023 Impact factor 4.2

Particles and Fields

Open Access

Eur. Phys. J. C (2021) 81: 1105
https://doi.org/10.1140/epjc/s10052-021-09898-9

Regular Article - Theoretical Physics

Heavy + light pseudoscalar meson semileptonic transitions

Zhen-Ni Xu¹^,2, Zhu-Fang Cui¹^,2, Craig D. Roberts¹^,2^c and Chang Xu¹^,2

¹ School of Physics, Nanjing University, 210093, Nanjing, Jiangsu, China
² Institute for Nonperturbative Physics, Nanjing University, 210093, Nanjing, Jiangsu, China

^c cdroberts@nju.edu.cn

Received: 31 March 2021
Accepted: 29 November 2021
Published online: 15 December 2021

Abstract

A symmetry-preserving regularisation of a vector $\times$ $\times$ vector contact interaction (SCI) is used to deliver a unified treatment of semileptonic transitions involving $π$ $\pi$ , K, $D_{(s)}$ $D_{(s)}$ , $B_{(s, c)}$ $B_{(s,c)}$ initial states. The framework is characterised by algebraic simplicity, few parameters, and the ability to simultaneously treat systems from Nambu–Goldstone modes to heavy+heavy mesons. Although the SCI form factors are typically somewhat stiff, the results are comparable with experiment and rigorous theory results. Hence, predictions for the five unmeasured $B_{s, c}$ $B_{s,c}$ branching fractions should be a reasonable guide. The analysis provides insights into the effects of Higgs boson couplings via current-quark masses on the transition form factors; and results on $B_{(s)} \to D_{(s)}$ $B_{(s)}\rightarrow D_{(s)}$ transitions yield a prediction for the Isgur–Wise function in fair agreement with contemporary data.

© The Author(s) 2021

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