Analysis of B_(c)→τν_(τ) at CEPC

作     者：郑太范 徐吉 曹璐 于丹 王伟 Soeren Prell 张若筠 阮曼奇 Taifan Zheng;Ji Xu;Lu Cao;Dan Yu;Wei Wang;Soeren Prell;Yeuk-Kwan ECheung;Manqi Ruan

作者机构：School of PhysicsNanjing UniversityNanjing 210023China INPACSKLPPCMOE KLPPCSchool of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Physikalisches Institut der Rheinischen Friedrich-Wilhelms-Universität Bonn53115 BonnGermany Institute of High Energy PhysicsBeijing 100049China Department of Physics and AstronomyIowa State UniversityAmesIAUSA 

出 版 物：《Chinese Physics C》 (中国物理C（英文版）)

年 卷 期：2021年第45卷第2期

页      面：39-47页

核心收录：

学科分类：0709[理学-地质学] 07[理学] 0708[理学-地球物理学] 0804[工学-仪器科学与技术] 0827[工学-核科学与技术] 0703[理学-化学] 070202[理学-粒子物理与原子核物理] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：This study was supported by the National Key Programme for S&T Research and Development(2016YFA0400400) the Beijing Municipal Science Technology Commission(Z181100004218003,Z 191100007219010) the Natural Science Foundation of China(11735010,11911530088,11775110,11690034) the Natural Science Foundation of Shanghai(15DZ2272100) the DFG Emmy-Noether(BE 6075/1-1)。 

主　　题：CEPC Flavor B_(c)meson 

摘      要：Precise determination of the B_(c)→τν_(τ) branching ratio provides an advantageous opportunity for under-standing the electroweak structure of the Standard Model,measuring the CKM matrix element |V_(cb)|,and probing new physics models.In this paper,we discuss the potential of measuring the process B_(c)→ τν_(τ)withτdecaying leptonically at the proposed Circular Electron Positron Collider(CEPC).We conclude that during the Z pole opera-tion,the channel signal can achieve five-σsignificance with~10^9 Z decays,and the signal strength accuracies for B_(c)→τν_(τ) can reach around 1%level at the nominal CEPC Z pole statistics of one tillion Z decays,assuming the total B_(c)→τν_(τ) yield is 3.6x 10^(6).Our theoretical analysis indicates the accuracy could provide a strong constraint on the general effective Hamiltonian for the b→cτν transition.If the total Be yield can be determined to 0(1%)level of accuracy in the future,these results also imply|V_(cb)| could be measured up to 0(1%)level of accuracy.