A Study of charm production by neutrinos in the NOMAD-STAR detector

The NOMAD neutrino experiment at the CERN SPS is described and the silicon tracking detector (STAR) that was placed in NOMAD is discussed in detail. An algorithm for the reconstruction of hits, tracks and vertices with the silicon tracker and utilising the Kalman filter method was developed and is also described. The vertex position resolution is determined to be 19um in the Y direction and 781um in the Z direction from Monte Carlo. The impact parameter resolution of STAR is determined to be 28um. From the sample of charged current neutrino interactions, a search is performed for the production and decay of D0 ' n+' Dt' D0 " and n +" mesons. From this analysis, the masses and lifetimes of the D mesons and resonances are determined to be: mno = 1.875 ± 0.075GeV < CTJJO > = 145~~~/lnl mn+ = 1.880 ± 0.088GeV < . +1 8:1 CTLJ+ > = 213_67 /lrn m1J.t = 1.973 ± 0.061GeV < CT n_t > = 199~.~~2 /nll rnno• = 1.973 ± 0.046GeV mn+• = 2.072 ± 0.031GeV The production rates (R) per uμ. charged current deep inelastic interaction of D mesons are determined to be: R(D0 ) = 4.2 ± 2.0% R(D+) = 2.4 ± 1.3% R(Dt) = 0.64 ± 0.36% R ( D o•) = 3.3 ± 6.2 oizc R(n+*) = 1.7 ± 2.6% The inclusive production rate of charmed mesons is determined to be 7.2 ± 2.4 %.