Measurements of the local and non-local contributions in B^±→K^±μ^±μ^∓ decays using LHCb data

Abstract

In the study of the decay of B mesons, the observed deviations from standard model predictions could potentially be explained by underestimated non-local hadronic intermediate states. To answer this question, the contribution of local and non-local contributions to B^±→K^±μ^±μ^∓ decays are measured by analysing the invariant dimuon mass distribution in the range: 300 < m_μμ < 4700 MeV/ c² (0.09 < q² < 22.09 GeV²/c⁴ ). The analysis uses pp collision data collected by the LHCb experiment between 2011 and 2018 corresponding to an integrated luminosity of 9 fb⁻¹. The non-local contributions are modelled using hadronic dispersion relations including a description of intermediate one-particle and two-particle states which scatter to a pair of muons. The largest one-particle states interfering with the local contribution are J/ψ and ψ(2S) and the two-particle states described are DD, D^∗ D^∗ and DD^∗. The interference from J/ψ is observed to be small while a large component of the two-particle states, along with the ψ(2S), is observed to destructively interfere with the local contribution. The effect of this interference on the vector current ( C₉ ) and axial-vector current ( C₁₀ ) Wilson coefficients, which encode heavy standard model and beyond standard model physics, are discussed. The branching fractions of the one-particle and two-particle states are also measured.

Date of Award	27 Sept 2022
Original language	English
Awarding Institution	University of Bristol
Supervisor	Konstantinos A. Petridis (Supervisor) & Jonas H Rademacker (Supervisor)