Xic' Production at BABAR

TL;DR

This paper reports the first measurements of production rates and decay properties of Xic' baryons at BABAR, using 232 fb-1 of data, including branching fractions, cross-sections, and spin determination.

Contribution

First measurement of Xic' baryon production rates, decay branching fractions, and spin properties in e+e- collisions at BABAR.

Findings

Measured branching fractions for B decays to Xic' states.

Determined cross-sections for continuum production of Xic' baryons.

Confirmed the J=1/2 spin assignment for Xic' decays.

Abstract

Using 232 fb-1 of data collected by the BABAR detector, the Xic'+ and Xic'0 baryons are reconstructed through the decays: Xic'+ -> Xic+ gamma and Xic'0 -> Xic0 gamma, where Xic+ -> Xi- pi+ pi+ and Xic0 -> Xi- pi+. By measuring the efficiency-corrected yields in different intervals of the center-of-mass momentum, the production rates from B decays and from the continuum are extracted. For production from B decays, the branching fractions are found to be B(B -> Xic'+ X) x B(Xic+ -> Xi- pi+ pi+) = [ 1.69 +- 0.17 (exp.) +- 0.10 (model) ] x 10^-4 and B(B -> Xic'0 X) x B(Xic0 -> Xi- pi+) = [ 0.67 +- 0.07 (exp.) +- 0.03 (model) ] x 10^-4. For production from the continuum the cross-sections are found to be sigma(e+ e- -> Xic'+ X) x B(Xic+ -> Xi- pi+ pi+) = 141 +- 24 (exp.) +- 19 (model) fb and sigma(e+ e- -> Xic'0 X) x B(Xic0 -> Xi- pi+) = 70 +- 11 (exp.) +- 6 (model) fb. The helicity angle distributions of Xic' decays are studied and found to be consistent with J = 1/2.