We apply a genetic programming technique to search for the doubly Cabibbo suppressed decays Λc+→pK+π− and Ds+→K+K+π−. We normalize these decays to their Cabibbo favored partners and find ...BR(Λc+→pK+π−)/BR(Λc+→pK−π+)=(0.05±0.26±0.02)% and BR(Ds+→K+K+π−)/BR(Ds+→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 <0.46 and <0.78%, respectively. This is the first successful use of genetic programming in a high energy physics data analysis.
We report measurements of the charm–anticharm production asymmetries for Λc+, Σc++, Σc0, Σc++∗, Σc0∗, and Λc+(2625) baryons from the Fermilab photoproduction experiment FOCUS (E831). These ...asymmetries are integrated over the region where the spectrometer has good acceptance. In addition, we have obtained results for the photoproduction asymmetries of the Λc baryons as functions of pL, pT2, and xF. The integrated asymmetry for Λc+ production, (σΛc+−σΛc−)/(σΛc++σΛc−), is 0.111±0.018±0.012, significantly different from zero. The asymmetries of the excited states are consistent with the Λc asymmetry.
We present an analysis of the decay D0→K+π− based on FOCUS data. From a sample of 234 signal events, we find a branching ratio of Γ(D0→K+π−)Γ(D0→K−π+)=(0.429−0.061+0.063±0.027)% under the assumptions ...of no mixing and no CP violation. Allowing for CP violation, we find a branching ratio of (0.429±0.063±0.028)% and a CP asymmetry of 0.18±0.14±0.04. The branching ratio for the case of mixing with no CP violation is (0.381−0.163+0.167±0.092)%. We also present limits on charm mixing.
Study of the D0→K+K−π+π− decay Link, J.M.; Yager, P.M.; Anjos, J.C. ...
Physics letters. B,
03/2005, Volume:
610, Issue:
3-4
Journal Article
Peer reviewed
Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement for the Cabibbo-suppressed decay mode D0→K+K−π+π−. We measure: ...Γ(D0→K+K−π+π−)/Γ(D0→K−π−π+π+)=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 D0→K1(1270)+K−, D0→K1(1400)+K− and D0→ρ(770)0ϕ(1020).
A study of D0→KS0KS0X decay channels Link, J.M.; Yager, P.M.; Anjos, J.C. ...
Physics letters. B,
02/2005, Volume:
607, Issue:
1-2
Journal Article
Peer reviewed
Using data from the FOCUS experiment (FNAL-E831), we report on the decay of D0 mesons into final states containing more than one KS0. We present evidence for two Cabibbo favored decay modes, ...D0→KS0KS0K−π+ and D0→KS0KS0K+π−, and measure their combined branching fraction relative to D0→K¯0π+π− to be Γ(D0→KS0KS0K±π∓)Γ(D0→K¯0π+π−)=0.0106±0.0019±0.0010. Further, we report new measurements of Γ(D0→KS0KS0KS0)Γ(D0→K¯0π+π−)=0.0179±0.0027±0.0026, Γ(D0→K0K¯0)Γ(D0→K¯0π+π−)=0.0144±0.0032±0.0016, and Γ(D0→KS0KS0π+π−)Γ(D0→K¯0π+π−)=0.0208±0.0035±0.0021 where the first error is statistical and the second is systematic.
Using data collected by the fixed target Fermilab experiment FOCUS, we present several first measurements for the semileptonic decay D0→K¯0π−μ+ν. Using a model that includes a K¯0π−s-wave component, ...we measure the form factor ratios to be rv=1.71±0.68±0.34 and r2=0.91±0.37±0.10 and the s-wave amplitude to be A=0.35±0.22±0.05 GeV−1. Finally, we measure the vector semileptonic branching ratio Γ(D0→K*(892)−μ+ν)Γ(D0→K¯0π−π+)=0.337±0.034±0.013.
We present a new measurement of the branching ratio of the Cabibbo suppressed decay D0→π−μ+ν relative to the Cabibbo favored decay D0→K−μ+ν and an improved measurement of the ratio |f+π(0)/f+K(0)|. ...Our results are 0.074±0.008±0.007 for the branching ratio and 0.85±0.04±0.04±0.01 for the form factor ratio, respectively.
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