Exclusive semileptonic Bc-meson decays to radially excited charmonium and charm meson states

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2022-08, Vol.82 (8)
• Main Authors: Nayak, Lopamudra, Dash, P. C., Kar, S., Barik, N.
• Format: Article
• Language: English
• Subjects: Astronomy; Astrophysics and Cosmology; Asymmetry; Charm (particle physics); Elementary Particles; Flavor (particle physics); Form factors; Hadrons; Heavy Ions; Leptons; Measurement Science and Instrumentation; Nuclear Energy; Nuclear Physics; Particle decay; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quarks; Regular Article - Theoretical Physics; Standard model (particle physics); String Theory
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-022-10724-z

In the wake of recent measurements of ratios of semileptonic branching fractions: R J / ψ , R D and R D ∗ reported by the LHCb, BELLE and HFLAV Collaborations, we calculate invariant form factors for the exclusive semileptonic B c -meson decays to radially excited charmonium and charm meson states in the full kinematical region within the framework of relativistic independent quark (RIQ) model. We evaluate the lepton mass effect in the decay processes induced by b → c , u transition at the quark level. Our predictions on branching fractions for B c → η c / ψ ( n S ) are found ∼ 10 - 2 - 10 - 4 and that for B c → D ∗ ( n S ) are ∼ 10 - 4 in their e - decay modes, which lie within the detection accuracy of current experiment. Our predictions on branching fractions, forward backward asymmetry and asymmetry parameter are found in reasonable agreement with other model predictions; which can hopefully be tested in future experiments at LHC and Tevatron. Our predicted observable R in this sector are found comparable to other standard model (SM) predictions that violate the lepton flavor universality hinting at new physics beyond SM.