| Article | |
| Report number | arXiv:2209.08851 ; SI-HEP-2022-26 ; P3H-22-094 ; CERN-TH-2022-144 |
| Title | New sum rules for the B$_{c}$→ J/ψ form factors |
| Author(s) | Bordone, Marzia (CERN) ; Khodjamirian, Alexander (Siegen U.) ; Mannel, Th. (Siegen U.) |
| Publication | 2023-01-09 |
| Imprint | 2022-09-19 |
| Number of pages | 31 |
| Note | 30 pages, 3 figures. v2: version accepted in JHEP |
| In: | JHEP 2301 (2023) 032 |
| DOI | 10.1007/JHEP01(2023)032 (publication) |
| Subject category | hep-ph ; Particle Physics - Phenomenology |
| Abstract | We derive new sum rules for the form factors of the $B_c\to J/\psi\, \ell \bar{\nu}_\ell$ semileptonic transitions, employing the vacuum-to-$B_c$ correlation function of the $J/\psi$-interpolating and $b\to c$ weak currents. In the heavy quark limit and at a space-like momentum transfer to the weak current, a local operator-product expansion is valid for this correlation function. As a result, in the leading power, the non-perturbative input is reduced to the decay constant of $B_c$ meson. Furthermore, applying hadronic dispersion relation in the $J/\psi$ channel, we find that a non-vanishing OPE spectral density in the duality interval of $J/\psi$ emerges only at $\mathcal{O}(\alpha_s)$. We calculate this density in the relevant kinematic regime. The $B_c\to J/\psi$ form factors at space-like momentum transfer are then calculated from the new sum rules. |
| Copyright/License | preprint: (License: arXiv nonexclusive-distrib 1.0) publication: © 2023-2024 The Authors (License: CC-BY-4.0), sponsored by SCOAP³ |
Corresponding record in: Inspire
Record created 2022-09-20, last modified 2023-01-31