2024/03/19 by Jernej F. Kamenik, Kamenik, Jernej F., Nejc Košnik +3 · 1 citation
Engineering · Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph) #Particle Accelerators and Free-Electron Lasers #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2403.13056
openalex publication_date 2024/03/19 · openalex created_date 2024/03/22 · openalex updated_date 2026/07/28
We consider the combined measurements of CP-averaged decay rates and direct CP asymmetries of B^±→ K^± ℓ+ ℓ- and B^±→ π^± ℓ+ ℓ- to probe (non-local) four-quark operator matrix element contributions to rare semileptonic B meson decays. We also explore how their effects could be in principle disentangled from possible local new physics effects using U-spin relations. To this end, we construct a ratio of CP-odd decay rate differences which are exactly predicted within the standard model in the U-spin limit, while the leading U-spin breaking effects can also be systematically calculated. Our results motivate binned measurements of the direct CP asymmetry in B^±→ π^± ℓ+ ℓ- as well as dedicated theoretical estimates of U-spin breaking both in local form factors as well as in four-quark matrix elements.