Measurement of the masses and widths of the Σ c ( 2455 ) + and Σ c ( 2520 ) + baryons

Abstract

Using 980 fb−1 of data collected with the Belle detector operating at the KEKB asymmetric-energy eþe− collider, we report the measurements of the masses, and the first measurements of the instrinsic widths, of the Σcð2455Þþ and Σcð2520Þþ charmed baryons. We find MðΣcð2455ÞþÞ − MðΛþ c Þ ¼ 166.17 0.05þ0.16 −0.07 MeV=c2, ΓðΣcð2455ÞþÞ ¼ 2.3 0.3 0.3 MeV=c2, MðΣcð2520ÞþÞ − MðΛþ c Þ ¼ 230.9 0.5þ0.5 −0.1 MeV=c2, and ΓðΣcð2520ÞþÞ ¼ 17.2þ2.3þ3.1 −2.1−0.7 MeV=c2, where the uncertainties are statistical and systematic, respectively. These measurements can be used to test models of the underlying quark structure of the Σc states.