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

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.Comment: 18 pages, to be submitted to Phys. Lett. B For a list of the FOCUS collaboration, see http://www-focus.fnal.gov/authors.htm

Study of the decay asymmetry parameter and CP violation parameter in the Λc+ → Λπ+ decay

Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the weak decay-asymmetry parameter αΛc in Λc+→Λπ+ decay. Comparing particle with antiparticle decays, we obtain the first measurement of the CP violation parameter A≡αΛc+α Λc/αΛc-αΛc. We obtain αΛc=-0.78±0.16±0.19 and A=-0.07±0.19±0.24 where errors are statistical and systematic. © 2006 Elsevier B.V. All rights reserved

Search for a pentaquark decaying to pK(s)(0)

AbstractWe present a search for a pentaquark decaying strongly to pKS0 in γN collisions at a center-of-mass energy up to 25 GeV. Finding no evidence for such a state in the mass range of 1470 MeV/c2 to 2200 MeV/c2, we set limits on the yield and on the cross section times branching ratio relative to Σ∗(1385)± and K∗(892)+