Test of lepton universality with W boson decays

用 W 玻色子衰变检验轻子普遍性

基本信息

批准号：
2108737
负责人：
金额：
--
依托单位：
University of Warwick
依托单位国家：
英国
项目类别：
Studentship
财政年份：
2018
资助国家：
英国
起止时间：
2018 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=studentship-2108737
关键词：
Test lepton universality boson decays

项目摘要

This project aims to exploit the large LHCb Run-II dataset to make a precision test of lepton universality with W boson decays.In the standard model the W boson decays with equal branching fraction, up to tiny corrections, to the three generations of leptons.For more than a decade there has been an anomalous measurement, by experiments at the LEP collider, of the W branching ratio to third generation leptons.This is yet to be tested by any other experiment. Furthermore there have been several recent measurements by three different experiments, including LHCb, which hint at a violation of lepton universality in beauty hadron decays.LHCb is well suited to make the first test of the LEP anomaly, using muonic decays of the tau lepton.This is thanks to its ability to trigger on soft muons, and to resolve the subtle impact parameter signature of the tau decay.The idea will be to measure the ratio of the decay rate of W->mu nu compared to that of W -> tau nu, with the single muon final state.Developing a strategy to subtract the background from high transverse momentum charm hadron decays will be one of the main challenges.Novel statistical methods will be required in order to exploit different control samples and observables to constrain the effect of this background.This promises to be a very excited research project, which addresses a timely and important physics question, and has the potential for a high impact result.

该项目旨在利用大型LHCB RUN-II数据集对Lepton的普遍性进行精确测试，以W Boson衰变进行精确测试。在标准模型中，W Boson衰变以相等的分支分支，最小的校正，对Leptons的较小校正，对leptons的三个世代进行了超过十年的分支超过十年的分支机构，该型号是通过实验的三分之一的，该型号是在实验中的三分之一的。 Leptons。尚未通过任何其他实验对此进行测试。 Furthermore there have been several recent measurements by three different experiments, including LHCb, which hint at a violation of lepton universality in beauty hadron decays.LHCb is well suited to make the first test of the LEP anomaly, using muonic decays of the tau lepton.This is thanks to its ability to trigger on soft muons, and to resolve the subtle impact parameter signature of the tau decay.The idea will与w-> tau nu相比，要衡量w-> mu nu的衰减率的比率，单个muon的最终状态。制定一种策略，从高横向动量魅力型生育体衰减中减去背景是主要挑战之一。为了使不同的控制型和观察到的效果构成一定的效果，需要进行统计学的统计方法。解决了一个及时，重要的物理问题，并有可能产生高影响结果。