2016/08/29 by Stefan Meinel, Meinel, Stefan, Gumaro Rendon +1
Engineering · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Lattice (hep-lat) #High Energy Physics - Phenomenology (hep-ph) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #Superconducting Materials and Applications
paper · pdf · doi:10.48550/arxiv.1608.08110
openalex publication_date 2016/08/29 · openalex created_date 2022/10/11 · openalex updated_date 2026/07/28
Experimental results for mesonic b → s μ+ μ- decays show a pattern of deviations from Standard-Model predictions, which could be due to new fundamental physics or due to an insufficient understanding of hadronic effects. Additional information on the b → s μ+ μ- transition can be obtained from Λb decays. This was recently done using the process Λb → Λμ+ μ-, where the Λ is the lightest strange baryon. A further interesting channel is Λb → p+ K- μ+ μ-, where the p+ K- final state receives contributions from multiple higher-mass Λ resonances. The narrowest and most prominent of these is the Λ(1520), which has JP=\frac32-. Here we present an ongoing lattice QCD calculation of the relevant Λb → Λ(1520) form factors. We discuss the choice of interpolating field for the Λ(1520), and explain our method for extracting the fourteen Λb → Λ(1520) helicity form factors from correlation functions that are computed in the Λ(1520) rest frame. We present preliminary numerical results at a pion mass of 340 MeV and a lattice spacing of 0.11 fm. This calculation uses a domain-wall action for the u, d, and s quarks and a relativistic heavy-quark action for the b quark, and is based on gauge-field configurations generated by the RBC and UKQCD Collaborations.