Strong coupling constant of vector bottomonium to the pseudoscalar and vector $B_c$ mesons via QCD sum rules

TL;DR

This paper calculates the strong coupling constants involving bottomonium and B_c mesons using QCD sum rules, including gluon condensate contributions, providing numerical estimates for these couplings.

Contribution

It introduces a detailed QCD sum rule approach to evaluate strong couplings of bottomonium with pseudoscalar and vector B_c mesons, incorporating gluon condensate effects.

Findings

Calculated $g_{ ext{Upsilon} B_c^{V} B_c^{PS}}$ as 1.67±0.52 GeV^{-1}

Determined $g_{ ext{Upsilon} B_c^{PS} B_c^{V}}$ as 0.87±0.25 GeV^{-1}

Included gluon condensate contributions as radiative corrections in the sum rules.

Abstract

The strong coupling constant $g_{\Upsilon B_c^{ps} B_c^V}$ is evaluated using the three-point QCD sum rules. The correlation functions used to calculate these strong coupling constants contain contributions of both $B_c^V$ and $B_c^{ps}$ mesons as off-shell states with contributions of two gluon condensates as a radiative corrections. The results, $g_{\Upsilon B_c^V B_c^{PS}}=1.67\pm 0.52 GeV^{-1}$ for $B_c^{Ps}$ off-shell and $g_{\Upsilon B_c^{PS}B_c^V}=(0.87\pm0.25) GeV^{-1}$ for $B_c^V$ off-shell are obtained for the relevant strong coupling constants