28 research outputs found
Spin alignment of mesons produced in neutron-carbon interactions
A new precise measurements of spin density matrix element of
mesons produced inclusively in neutron-carbon interactions at
\~60 GeV have been carried out in the EXCHARM experiment at the Serpukhov
accelerator. The values of obtained in the transversity frame are
for and
for . Significant
dependence of has been observed in production.Comment: 8 pages, LaTeX, 3 eps figure
Study of Charm Fragmentation into D^{*\pm} Mesons in Deep-Inelastic Scattering at HERA
The process of charm quark fragmentation is studied using meson
production in deep-inelastic scattering as measured by the H1 detector at HERA.
Two different regions of phase space are investigated defined by the presence
or absence of a jet containing the meson in the event. The
parameters of fragmentation functions are extracted for QCD models based on
leading order matrix elements and DGLAP or CCFM evolution of partons together
with string fragmentation and particle decays. Additionally, they are
determined for a next-to-leading order QCD calculation in the fixed flavour
number scheme using the independent fragmentation of charm quarks to
mesons.Comment: 33 pages, submitted to EPJ