2024/10/21 by Nicola Losacco, Losacco, Nicola
Physics and Astronomy · Social Sciences · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #International Science and Diplomacy #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.2410.16045
openalex publication_date 2024/10/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The Belle Collaboration has measured the complete set of angular coefficient functions for the decays B → D^* (D π) ℓ νℓ, where ℓ = e, μ, in four bins of the variable w=mB2+mD^*2-q2 \over 2 mB mD^*, with q the momentum of the lepton pair. In SM this measurement is instrumental in determining the hadronic form factors in the B → D^* matrix elements of the SM weak current, thereby refining the measurement of | Vcb |. On the other hand, it can be used to assess the impact of possible new physics contributions. I consider an extension of the SM effective Hamiltonian that governs this mode, incorporating the complete set of Lorentz invariant d = 6 operators compatible with the gauge symmetry of the theory. The measured angular coefficient functions play a pivotal role in constraining the couplings in the generalized effective Hamiltonian.