J.M. Link

Search for CP violation in the decays D+ ---> K(S) pi+ and D+ ---> K(S) K+

A high statistics sample of photo-produced charm from the FOCUS(E831) experiment at Fermilab has been used to search for direct CP violation in the decays D+->K_S pi+ and D+ ->K_S K+. We have measured the following asymmetry parameters relative to D+->K-pi+pi+: A_CP(K_S pi+) = (-1.6 +/- 1.5 +/- 0.9)%, A_CP(K_S K+) = (+6.9 +/- 6.0 +/- 1.5)% and A_CP(K_S K+) = (+7.1 +/- 6.1 +/- 1.2)% relative to D+->K_S pi+. The first errors quoted are statistical and the second are systematic. We also measure the relative branching ratios: \Gamma(D+->\bar{K0}pi+)/\Gamma(D+->K-pi+pi+) = (30.60 +/- 0.46 +/- 0.32)%, \Gamma(D+->\bar{K0}K+)/\Gamma(D+->K-pi+pi+) = (6.04 +/- 0.35 +/- 0.30)% and \Gamma(D+->\bar{K0}K+)/\Gamma(D+->\bar{K0}pi+) = (19.96 +/- 1.19 +/- 0.96)%.

Measurement of the D(s)+ lifetime.

A high statistics measurement of the D(s)+ lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis of the two decay modes, D(s)+ --> phi(1020)pi+ and D(s)+ -->K*(892)0K+, used for the measurement. The measured lifetime is 507.4 +/- 5.5(stat) +/- 5.1(syst) fs using 8961 +/- 105 D(s)+ --> phi(1020)pi+ and 4680 +/- 90 D(s)+ --> K*(892)0K+ decays. This is a significant improvement over the present world average.

Search for

Abstract We apply a genetic programming technique to search for the doubly Cabibbo suppressed decays Λ c + → p K + π − and D s + → K + K + π − . We normalize these decays to their Cabibbo favored partners and find BR ( Λ c + → p K + π − ) / BR ( Λ c + → p K − π + ) = ( 0.05 ± 0.26 ± 0.02 ) % and BR ( D s + → K + K + π − ) / BR ( D s + → K − K + π + ) = ( 0.52 ± 0.17 ± 0.11 ) % where the first errors are statistical and the second are systematic. Expressed as 90% confidence levels (CL), we find

\Lambda_c^+ \to p K^+ \pi^-

Abstract We apply a genetic programming technique to search for the doubly Cabibbo suppressed decays Λ c + → p K + π − and D s + → K + K + π − . We normalize these decays to their Cabibbo favored partners and find BR ( Λ c + → p K + π − ) / BR ( Λ c + → p K − π + ) = ( 0.05 ± 0.26 ± 0.02 ) % and BR ( D s + → K + K + π − ) / BR ( D s + → K − K + π + ) = ( 0.52 ± 0.17 ± 0.11 ) % where the first errors are statistical and the second are systematic. Expressed as 90% confidence levels (CL), we find

and

Using data from the FOCUS (E831) experiment at Fermilab, the authors present a new measurement for the Cabibbo-suppressed decay mode D{sup 0} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}. They measure: {Lambda}(D{sup 0} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -})/{Lambda}(D{sup 0} {yields} K{sup -}{pi}{sup -}{pi}{sup +}{pi}{sup +}) = 0.0295 {+-} 0.0011 {+-} 0.0008. An amplitude analysis has been performed in order to determine the resonant substructure of this decay mode. The dominant components are the decays D{sup 0} {yields} K{sub 1}(1270){sup +} K{sup -}, D{sup 0} {yields} K{sub 1}(1400){sup +}K{sup -} and D{sup 0} {yields} {rho}(770){sup 0}{phi}(1020).Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the branching ratio for the Cabibbo-favored decay mode

D_s^+ \to K^+ K^+ \pi^-

D^0 \to K^-K^+\pi^-\pi^+

Using Genetic Programming Event Selection

. From a sample of

Search for Lambda+(c) ---> p K+ pi- and D+(s) ---> K+ K+ pi- using genetic programming event selection

2669 \pm 101

Study of the D0 ---> K+ K- pi+ pi-

fully reconstructed

Search forCPViolation in the decaysD+→KSπ+andD+→KSK+

D^0 \to K^-K^+\pi^-\pi^+