Constraining inverse moment of B-meson distribution amplitude using Lattice QCD data

by Dr Ipsita Ray (Indian Institute of Technology Gandhinagar)

Thursday 5 Oct 2023, 12:00 → 13:30 Europe/Madrid

IFAE Seminar Room (Face-to-face Only)

We constrain the inverse moment of the B-meson light-cone distribution amplitude in heavy quark effective theory, \lambda_B,  using form factor estimates from Lattice QCD collaboration. The estimation of the parameter \lambda_B has, until now, relied solely on QCD sum rule methods and deals with significant uncertainty. In this work, we express the form factors for the B -> K channel, calculated within the light-cone sum rule (LCSR) approach, in terms of the B-meson light-cone distribution amplitudes (LCDAs). By incorporating recent Lattice results from the HPQCD collaboration for the B -> K form factors at zero momentum transfer (q2 = 0), we impose constraints on this parameter. Consequently, we achieve a twofold reduction in uncertainty compared to the QCD sum rule estimate, yielding \lambda_B=338 \pm 68 MeV, when the B-meson LCDAs are expressed in the Exponential model. Additionally, we compare the form factor predictions, using the constrained \lambda_B value, with the earlier analyses for other channels, such as B -> \pi and B -> D.