(D)OVER-BAR-0-MESON PRODUCTION IN INTERACTIONS OF NEUTRONS WITH HYDROGEN, CARBON, AND ALUMINUM NUCLEI AT 37.5-70 GEV

The production of charmed D0BAR mesons of mass 1866 +/- 8 MeV/c2 has been observed in interactions of neutrons with hydrogen, carbon, and aluminum nuclei for beam energies in the range 37.5-70 GeV. The D0BAR-meson signal was observed in the effective-mass spectrum of the K+pi+pi-pi- system. The kinematic region of D0BAR-meson detection was 30 less-than-or-equal-to P(L) less-than-or-equal-to 65 GeV/c and 0 less-than-or-equal-to P(T) less-than-or-equal-to 1 GeV/c. The cross sections for D0BAR-meson production have been found for this region: DELTAsigma(H) = 3.2 +/- 1.1 mub, DELTAsigma(C) = 28.6 +/- 9.7 mub for the carbon nucleus, and DELTAsigma(A1) = 51.6 +/- 17.0 mub for the aluminum nucleus. The A dependence of the D0BAR-meson production cross section is written as DELTAsigma(A) = sigma0A(alpha) with the parameters sigma0 = (1.5 +/- 0.8) DELTAsigma(H) and alpha = 0.73 +/- 0.23. The longitudinal-momentum spectrum for the observed kinematic region was approximated by the dependence dsigma/dx(F) approximately (1 - x(F))n with n = 2.3(+0.2/-0.3), and the transverse-momentum spectrum was approximated by dsigma/dp(T)2 approximately exp(- Bp(T)2) for B = 1.3(+0.2/-0.3) (GeV/c)-2.