Search for new light vector boson using J/Ψ at BESIII and Belle II

• Published in: The journal of high energy physics Vol. 2021; no. 4; pp. 1 - 17
• Main Authors: Ban, Kayoung, Jho, Yongsoo, Kwon, Youngjoon, Park, Seong Chan, Park, Seokhee, Tseng, Po-Yan
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2021; Springer Nature B.V; SpringerOpen
• Subjects: Asymmetry; Beyond Standard Model; Classical and Quantum Gravitation; Elementary Particles; Experiments; Gauge Symmetry; High energy physics; Luminosity; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Quarks; Regular Article - Theoretical Physics; Relativity Theory; Search methods; String Theory; Gauge Symmetry; Beyond Standard Model
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP04(2021)091

A bstract We investigate various search strategies for light vector boson X in O (10) MeV mass range using J/ Ψ associated channels at BESIII and Belle II: (i) J/ Ψ → η c X with 10 10 J/ Ψs at BESIII, (ii) J/ Ψ( η c + X ) + ℓ ℓ ¯ production at Belle II, and (iii) J/ Ψ + X with the displaced vertex in X → e + e − decay are analyzed and the future sensitivities at Belle II with 50 ab − 1 luminosity are comprehensively studied. By requiring the displaced vertex to be within the beam pipe, the third method results in nearly background-free analysis, and the vector boson-electron coupling and the vector boson mass can be probed in the unprecedented range, 10 − 4 ≤ | ε e | ≤ 10 − 3 and 9 MeV ≤ m X ≤ 100MeV with 50 ab − 1 at Belle II. This covers the favored signal region of 8 Be * anomaly recently reported by Atomki experiment with m X ≃ 17 MeV.