Probing the inverse moment of Bs-meson distribution amplitude via Bs→ ηs form factors
Abstract
We investigate the inverse moment of the Bs-meson light-cone distribution amplitude (LCDA), denoted as λBs and defined within the heavy quark effective theory, through the calculation of Bs → ηs form factors. The presence of the s-quark inside the Bs-meson dictates a notable departure of approximately 20% in the λB s value compared to the non-strange case λBq, as computed within the QCD sum rule approach, albeit with significant uncertainty. First, we compute the decay constant of the ηs-meson utilizing two-point sum rules while retaining finite s-quark mass contributions. Next, we constrain the parameter λB s by calculating Bs → ηs form factors within the light-cone sum rule approach, using Bs-meson LCDAs, and leveraging Lattice QCD estimates at zero momentum transfer from the HPQCD collaboration. Our findings yield λBs = 480 ± 92 MeV when expressing the Bs-meson LCDAs in the Exponential model, consistent with previous QCD sum rule estimate yet exhibiting a 1.5-fold improvement in uncertainty. Furthermore, we compare the form factor predictions, based on the extracted λB s value, with earlier analyses for other channels such as Bs → Ds and Bs → K.
- Publication:
-
Journal of High Energy Physics
- Pub Date:
- June 2024
- DOI:
- 10.1007/JHEP06(2024)212
- arXiv:
- arXiv:2402.16737
- Bibcode:
- 2024JHEP...06..212M
- Keywords:
-
- Bottom Quarks;
- Hadronic Matrix Elements and Weak Decays;
- Semi-Leptonic Decays;
- Lattice QCD;
- High Energy Physics - Phenomenology;
- High Energy Physics - Experiment;
- High Energy Physics - Lattice
- E-Print:
- Version accepted for publication in JHEP