Transition magnetic moment ofΛ→Σ0in QCD sum rules

Abstract

The $\ensuremath{\Lambda}\ensuremath{\rightarrow}{\ensuremath{\Sigma}}^{0}$ transition magnetic moment is computed in the QCD sum rules approach. Three independent tensor structures are derived in the external-field method using generalized interpolating fields. They are analyzed together with the $\ensuremath{\Lambda}$ and ${\ensuremath{\Sigma}}^{0}$ mass sum rules using a Monte-Carlo-based analysis, with attention to operator product expansion convergence, ground-state dominance, and the role of the transitions in the intermediate states. Relations between sum rules for magnetic moments of $\ensuremath{\Lambda}$ and ${\ensuremath{\Sigma}}^{0}$ and sum rules for transition magnetic moment of $\ensuremath{\Lambda}\ensuremath{\rightarrow}{\ensuremath{\Sigma}}^{0}$ are also examined. Our best prediction for the transition magnetic moment is ${\ensuremath{\mu}}_{{\ensuremath{\Sigma}}^{0}\ensuremath{\Lambda}}=1.60\ifmmode\pm\else\textpm\fi{}0.07{\ensuremath{\mu}}_{N}$. A comparison is made with other calculations in the literature.