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Title: Test of lepton flavor universality in B±→K±μ+μ− and B±→K±e+e− decays in proton-proton collisions at s=13TeV
Abstract

A test of lepton flavor universality inB±K±μ+μandB±K±e+edecays, as well as a measurement of differential and integrated branching fractions of a nonresonantB±K±μ+μdecay are presented. The analysis is made possible by a dedicated data set of proton-proton collisions ats=13TeVrecorded in 2018, by the CMS experiment at the LHC, using a special high-rate data stream designed for collecting about 10 billion unbiased b hadron decays. The ratio of the branching fractionsB(B±K±μ+μ)toB(B±K±e+e)is determined from the measured double ratioR(K)of these decays to the respective branching fractions of theB±J/ψK±withJ/ψμ+μande+edecays, which allow for significant cancellation of systematic uncertainties. The ratioR(K)is measured in the range1.1<q2<6.0GeV2, whereqis the invariant mass of the lepton pair, and is found to beR(K)=0.780.23+0.47, in agreement with the standard model expectationR(K)1. This measurement is limited by the statistical precision of the electron channel. The integrated branching fraction in the sameq2range,B(B±K±μ+μ)=(12.42±0.68)×108, is consistent with the present world-average value and has a comparable precision.

 
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Award ID(s):
2121686
NSF-PAR ID:
10521896
Author(s) / Creator(s):
Publisher / Repository:
IOP Publishing
Date Published:
Journal Name:
Reports on Progress in Physics
Volume:
87
Issue:
7
ISSN:
0034-4885
Format(s):
Medium: X Size: Article No. 077802
Size(s):
Article No. 077802
Sponsoring Org:
National Science Foundation
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