Search for resonance-enhanced 𝐶⁢𝑃 and angular asymmetries in the Λ+𝑐 →𝑝⁢𝜇+⁢𝜇− decay at LHCb

Physical Review D - Particles, Fields, Gravitation and Cosmology. 2025. Vol. 111. Article L091102.

Ratnikov F., Bocharnikov V., Boldyrev A., Hushchyn M., Ryzhikov A.

The first measurement of the 𝐶⁢𝑃 asymmetry of the decay rate (𝐴𝐶⁢𝑃) and the 𝐶⁢𝑃 average (Σ⁢𝐴FB) and 𝐶⁢𝑃 asymmetry (Δ⁢𝐴FB) of the forward-backward asymmetry in the muon system of Λ+𝑐 →𝑝⁢𝜇+⁢𝜇− decays is reported. The measurement is performed using a data sample of proton-proton collisions, recorded by the LHCb experiment from 2016 to 2018 at a center-of-mass energy of 13 TeV, which corresponds to an integrated luminosity of 5.4  fb−1. The asymmetries are measured in two regions of dimuon mass near the 𝜙-meson mass peak. The dimuon-mass integrated results are 𝐴𝐶⁢𝑃 =(−1.1 ±4.0 ±0.5)%, Σ⁢𝐴FB =(3.9 ±4.0 ±0.6)%, Δ⁢𝐴FB =(3.1 ±4.0 ±0.4)%, where the first uncertainty is statistical and the second systematic. The results are consistent with the conservation of 𝐶⁢𝑃 symmetry and the Standard Model expectations.

Keywords: физика частиц, elementary particle physics

Publication based on the results of: Development of theoretical foundations and methods of generative artificial intelligence and their application to heterogeneous domain area (2025)