The absolute branching fraction of the decay Λc(2625)+→Λc+π+π- is measured for the first time to be (50.2±5.7stat±3.5syst)% with 368.48 pb-1 of e+e- collision data collected by the BESIII detector at the center-of-mass energies of s=4.918 and 4.950 GeV. Although the central value of the result is lower than the theoretical prediction of 67%, obtained from isospin symmetry, they are consistent taking the uncertainties into account. This is the first absolute branching fraction measurement for Λc(2625)+ since it was found. This measurement is necessary to obtain the coupling constants for the transitions between s-wave and p-wave charmed baryons in heavy hadron chiral perturbation theory. In addition, we search for the decay Λc(2595)+→Λc+π+π-. No significant signal is observed, and the upper limit on its branching fraction is determined to be 85.0% at the 90% confidence level.
First measurements of the absolute branching fraction of Λc (2625)+ → Λc+ π+π- and upper limit on Λc (2595)+ → Λc+ π+π
Garzia, I.;Gramigna, S.;
2024
Abstract
The absolute branching fraction of the decay Λc(2625)+→Λc+π+π- is measured for the first time to be (50.2±5.7stat±3.5syst)% with 368.48 pb-1 of e+e- collision data collected by the BESIII detector at the center-of-mass energies of s=4.918 and 4.950 GeV. Although the central value of the result is lower than the theoretical prediction of 67%, obtained from isospin symmetry, they are consistent taking the uncertainties into account. This is the first absolute branching fraction measurement for Λc(2625)+ since it was found. This measurement is necessary to obtain the coupling constants for the transitions between s-wave and p-wave charmed baryons in heavy hadron chiral perturbation theory. In addition, we search for the decay Λc(2595)+→Λc+π+π-. No significant signal is observed, and the upper limit on its branching fraction is determined to be 85.0% at the 90% confidence level.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.