Study of theΛc+spin at aτ-charm factory

Abstract

A large cross section for e(+) e(-) -> Lambda(+)(c) (Lambda) over bar (-)(c) pair production near its threshold provides an opportunity to study the charm baryon Lambda(+)(c) (Lambda) over bar (-)(c) at a tau-charm factory with e(+) e(-) collisions. We call for the determination of the Lambda(+)(c) (Lambda) over bar (-)(c) spin using the process e(+) e(-) -> Lambda(+)(c) (Lambda) over bar (-)(c), Lambda(+)(c) -> pK(s)(0), and we present a formula and a method to estimate the statistical significance for spin assignment J = 1/2 and J = 3/2. A Monte Carlo study shows that the significance is sensitive to the number of observed events. A few hundred observed signal events will yield the statistical significance larger than five standard deviations.