arXiv subjects

E. M. Aitala et al

Publications and source records attributed to E. M. Aitala et al.

4 recordsLinked to original sources

arXiv1998

Measurement of the form-factor ratios for D+ --> K* l nu

The form factor ratios rv=V(0)/A1(0), r2=A2(0)/A1(0) and r3=A3(0)/A1(0) in the decay D+ --> K* l nu, K* -->K-pi+ have been measured using data from charm hadroproduction experiment E791 at Fermilab. From 3034 (595) signal (background) events in the muon channel, we obtain rv=1.84+-0.11+-0.09, r2=0.75+-0.08+-0.09 and, as a first measurement of r3, we find 0.04+-0.33 +-0.29. The values of the form factor ratios rv and r2 measured for the muon channel are combined with the values of rv and r2 that we have measured in the electron channel. The combined E791 results for the muon and electron channels are rv=1.87+-0.08+-0.07 and r2=0.73+-0.06+-0.08.

hep-ex↗

arXiv1997

Search for the pentaquark via the P^0_{{c bar}s} --> phi,pi,p decay

We report results of the first search for the pentaquark P_{{c bar}s} which is predicted to be a doublet of states: P^0_{{c bar}s}=({c bar} s u u d) and P^-_{{c bar}s}=({c bar} s d d u). A search was made for the decay P^0_{{c bar}s} --> phi,pi,p in data from Fermilab experiment E791, in which 500 GeV/c pi^- beam interacted with nuclear targets. We present upper limits at 90% confidence level for the ratio of cross section times branching fraction of this decay to that for the decay D_s --> phi,pi. The upper limits are 0.031 and 0.063 for M(P^0_{{c bar}s}) = 2.75 and 2.86 GeV/c^2, respectively, assuming a P^0_{{c bar}s} lifetime of 0.4 ps.

hep-ex↗

arXiv1997

Search for CP Violation in Charged D Meson Decays

We report results of a search for CP violation in the singly Cabibbo-suppressed decays D+ -> K- K+ pi+, phi pi+, K*(892)0 K+, and pi- pi+ pi+ based on data from the charm hadroproduction experiment E791 at Fermilab. We search for a difference in the D+ and D- decay rates for each of the final states. No evidence for a difference is seen. The decay rate asymmetry parameters A(CP), defined as the difference in the D+ and D- decay rates divided by the sum of the decay rates, are measured to be: A(CP)(K K pi) = -0.014 +/- 0.029, A(CP)(phi pi) = -0.028 +/- 0.036, A(CP)(K*(892) K) = -0.010 +/- 0.050, and A(CP)(pi pi pi) = -0.017 +/- 0.042.

hep-ex↗

arXiv1996

Measurement of the Branching Ratio B(D+ --> rho^0 l nu)/B(D+ --> K*0 l nu)

We report a measurement of the branching ratio B(D+-->rho^0 l nu)/ B(D+-->K*0 l nu) from the Fermilab charm hadroproduction experiment E791. Based on signals of 49+-17 events in the D+--> rho^0 e nu mode and 54+-18 events in the D+--> rho^0 mu nu mode, we measure B(D+-->rho^0 e nu)/B(D+-->K*0 e nu) = 0.045+-0.014+-0.009, and B(D+-->rho^0 mu nu)/B(D+-->K*0 mu nu) = 0.051+-0.015+-0.009. Combining the results from both the electronic and muonic modes, we obtain B(D+-->rho^0 l nu)/B(D+-->K*0 l nu) = 0.047+-0.013. This result is compared to theoretical predictions.

hep-ex↗