0000000000223765
AUTHOR
A. M. Cartacci
Measurement of charmed-particle lifetimes and decay branching ratios
The lifetimes of charmed hadrons photoproduced in nuclear emulsion have been computed from a practically background-free sample of 44 neutral particle decays and 42 charged-particle decays including 27D±, 11Λc+, 1Ds+ and 3 ambiguous decays. The values obtained are τ(D0, bar D0) = (3.6-0.8+1.2 ± 0.7) 10-13 s, τ(D±) = (5.0-1.0+1.5 ± 1.9) 10-13 s, τ(Λc+) = = (2.3-0.6+0.9 ± 0.4) 10-13 s. Branching ratios of various decay topologies were also obtained.
Cross sections and some features of charm photoproduction at gamma energies of 20-70 GeV
Abstract We report some results on charm photoproduction at γ energies ranging from 20 to 70 GeV. 36 events with pairs of charmed particles have been found in emulsions. The computed total cross section is (230±57)nb/nucleon. Frequencies of different production channels and some distributions are presented and compared with the predictions from a photon-gluon fusion model with string fragmentation.
Measurement of the Lifetime of Neutral Charmed Mesons
Abstract The lifetime of neutral charmed particles photoproduced in emulsion has been measured. The lifetime value presented here was obtained from a sample of 22D 0 mesons, 18 of which have their charmed partner seen in emulsion. The sample is essentially background-free. The result obtained is τ D 0 =(2.11 +1.21 -0.63 )×10 13 s The D 0 mass derived from 8 3C events is m D 0 = 1856 ± 36 MeV/ c 2 .
Charged charmed particle lifetime
Abstract We present the lifetime values obtained for D ± and Λ c + , photoproduced in nuclear emulsion in the WA58 experiment. In photohadronic interactions, pairs of charmed particles are produced. Out of 20 charged charmed particles used for lifetime evaluation, 17 have their charmed partner seen emulsion, being then essentially free from any background. The values of the lifetime are τ D ± = (3.91 −1.25 +2.35 ) × 10 −13 s, τ Λ c + = (2.22 −0.75 +1.34 ) × 10 −13 s.