b→cτ■ decay in supersymmetry with R-parity violation  

作　　者：Dong-Yang Wang Ya-Dong Yang Xing-Bo Yuan 王东洋;杨亚东;袁兴博(Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE),Central China Normal University)

机构地区：[1]Institute of Particle Physics and Key Laboratory of Quark and Lepton Physics (MOE),Central China Normal University

出　　处：《Chinese Physics C》2019年第8期46-58,共13页中国物理C（英文版）

基　　金：Supported by the National Natural Science Foundation of China(11775092,11521064,11435003,11805077);supported in part by the startup research funding from CCNU

摘　　要：In past years,several hints of lepton flavor universality（LFU）violation have emerged from the b→ct■,and b→sl+l-data.More recently,the Belle Collaboration has reported the first measurement of the D* longitudinal polarization fraction in the B→D*τV decay.Motivated by this intriguing result,along with the recent measurements of RJ/Ψand τ polarization,we present the study of b→ct■ decays in supersymmetry（SUSY）with R-parity violation（RPV）.We consider B→D（*）t■,Bc→ηct■,Bc→J/ψt■ and ∧b→∧ct■ modes and focus on the branching ratios,LFU ratios,forward-backward asymmetries,polarizations of daughter hadrons,and the τ lepton.The RPV SUSY was capable of explaining the RD（*） anomalies at the 2σ level,after taking into account various flavor constraints.In the allowed parameter space,the differential branching fractions and LFU ratios are largely enhanced by the SUSY effects,especially in the large dilepton invariant mass region.Moreover,a lower bound B（B+→K+vv）>7.37×10-6 is obtained.These observables could provide testable signatures at the high-luminosity LHC and SuperKEKB,and correlate with direct searches for SUSY.In past years, several hints of lepton flavor universality (LFU) violation have emerged from the b→sl^+l^-and data. More recently, the Belle Collaboration has reported the first measurement of the D^* longitudinal polarization fraction in the B→D^*τν decay. Motivated by this intriguing result, along with the recent measurements of and polarization, we present the study of b→cτν decays in supersymmetry (SUSY) with -parity violation (RPV). We consider B→D^(*)τν, Bc→ηcτν, Bc→J/ψτν and modes and focus on the branching ratios, LFU ratios, forward-backward asymmetries, polarizations of daughter hadrons, and the lepton. The RPV SUSY was capable of explaining the RD^(*)anomalies at the 2σ level, after taking into account various flavor constraints. In the allowed parameter space, the differential branching fractions and LFU ratios are largely enhanced by the SUSY effects, especially in the large dilepton invariant mass region. Moreover, a lower bound 10^-6 is obtained. These observables could provide testable signatures at the high-luminosity LHC and SuperKEKB, and correlate with direct searches for SUSY.

关 键 词：SUPERSYMMETRY R-PARITY VIOLATION heavy FLAVOR HADRON b-quark semi-leptonic DECAY 

分 类 号：O572.33[理学—粒子物理与原子核物理]