Study of the decay asymmetry parameter and CP violation parameter in the Lambdac+ --> Lambda pi+ decay

TL;DR

This paper reports a new measurement of the decay asymmetry parameter and the first measurement of CP violation in Lambda_c+ decays, using data from the Fermilab FOCUS experiment, providing insights into weak decay processes and CP symmetry.

Contribution

It provides the first measurement of the CP violation parameter in Lambda_c+ decays and refines the decay asymmetry parameter using Fermilab data.

Findings

Measured alpha(Lambdac) = -0.78 ± 0.16 ± 0.13

First measurement of CP violation parameter A = -0.07 ± 0.19 ± 0.12

Results are consistent with no CP violation within uncertainties.

Abstract

Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the weak decay-asymmetry parameter alpha(Lambdac) in Lambdac --> Lambda pi decay. Comparing particle with antiparticle decays, we obtain the first measurement of the CP violation parameter : A = [alpha(Lambdac)+alpha(antiLambda_c)]/[alpha(Lambdac)-alpha(antiLambda_c)]. We obtain alpha(Lambdac)=-0.78+-0.16+-0.13 and A = -0.07+-0.19+-0.12 where errors are statistical and systematic.