Unitarity bounds with subthreshold and anomalous cuts for b -hadron decays

IF 5 2区物理与天体物理 Q1 Physics and Astronomy

Physical Review D Pub Date : 2025-02-10 DOI:10.1103/physrevd.111.l031501

Abinand Gopal, Nico Gubernari

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引用次数: 0

Abstract

We derive a generalization of the Boyd-Grinstein-Lebed (BGL) parametrization. Most form factors (FFs) in b-hadron decays exhibit additional branch cuts—namely subthreshold and anomalous branch cuts—beyond the “standard” unitarity cut. These additional cuts cannot be adequately accounted for by the BGL parametrization. For instance, these cuts arise in the FFs for B→D(*), B→K(*), and Λb→Λ processes, which are particularly relevant from a phenomenological standpoint. We demonstrate how to parametrize such FFs and derive unitarity bounds in the presence of subthreshold and/or anomalous branch cuts. Our work paves the way for a wide range of new FF analyses based solely on first principles, thereby minimizing systematic uncertainties.

Published by the American Physical Society

2025

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来源期刊

Physical Review D 物理-天文与天体物理

CiteScore

9.20

自引率

36.00%

发文量

审稿时长

2 months

期刊介绍： Physical Review D (PRD) is a leading journal in elementary particle physics, field theory, gravitation, and cosmology and is one of the top-cited journals in high-energy physics. PRD covers experimental and theoretical results in all aspects of particle physics, field theory, gravitation and cosmology, including: Particle physics experiments, Electroweak interactions, Strong interactions, Lattice field theories, lattice QCD, Beyond the standard model physics, Phenomenological aspects of field theory, general methods, Gravity, cosmology, cosmic rays, Astrophysics and astroparticle physics, General relativity, Formal aspects of field theory, field theory in curved space, String theory, quantum gravity, gauge/gravity duality.