Decays and Lifetime of B_c in QCD Sum Rules

TL;DR

This paper calculates B_c meson decay form factors and lifetime using QCD sum rules, incorporating Coulomb-like corrections and spin symmetry relations, providing theoretical predictions for semileptonic and nonleptonic decays.

Contribution

It introduces a comprehensive QCD sum rule approach including Coulomb corrections and spin symmetry relations to evaluate B_c decay form factors and lifetime.

Findings

Calculated form factors for B_c decays with Coulomb corrections.

Derived relations based on heavy quark spin symmetry.

Estimated B_c lifetime by summing dominant decay modes.

Abstract

In the framework of three-point QCD sum rules, the form factors for the semileptonic decays of B_c^+ -> B_s(B_s^*) l \nu are calculated with account for the Coulomb-like alpha_s/v-corrections in the heavy quarkonium. The generalized relations due to the spin symmetry of HQET/NRQCD for the form factors are derived at the recoil momentum close to zero. The nonleptonic decays are studied using the assumption on the factorization. The B_c meson lifetime is estimated by summing up the dominating exclusive modes in the c -> s transition combining the current calculations with the previous analysis of b -> c decays in the sum rules of QCD and NRQCD.