11 research outputs found
Inclusive Production Cross Sections from 920 GeV Fixed Target Proton-Nucleus Collisions
Inclusive differential cross sections and
for the production of \kzeros, \lambdazero, and
\antilambda particles are measured at HERA in proton-induced reactions on C,
Al, Ti, and W targets. The incident beam energy is 920 GeV, corresponding to
GeV in the proton-nucleon system. The ratios of differential
cross sections \rklpa and \rllpa are measured to be and , respectively, for \xf . No significant dependence upon the
target material is observed. Within errors, the slopes of the transverse
momentum distributions also show no significant
dependence upon the target material. The dependence of the extrapolated total
cross sections on the atomic mass of the target material is
discussed, and the deduced cross sections per nucleon are
compared with results obtained at other energies.Comment: 17 pages, 7 figures, 5 table
The QCD transition temperature: results with physical masses in the continuum limit II.
We extend our previous study [Phys. Lett. B643 (2006) 46] of the cross-over
temperatures (T_c) of QCD. We improve our zero temperature analysis by using
physical quark masses and finer lattices. In addition to the kaon decay
constant used for scale setting we determine four quantities (masses of the
\Omega baryon, K^*(892) and \phi(1020) mesons and the pion decay constant)
which are found to agree with experiment. This implies that --independently of
which of these quantities is used to set the overall scale-- the same results
are obtained within a few percent. At finite temperature we use finer lattices
down to a <= 0.1 fm (N_t=12 and N_t=16 at one point). Our new results confirm
completely our previous findings. We compare the results with those of the
'hotQCD' collaboration.Comment: 19 pages, 8 figures, 3 table
The Outer Tracker Detector of the HERA-B Experiment. Part III: Operation and Performance.
In this paper we describe the operation and performance of the HERA-B Outer
Tracker, a 112674 channel system of planar drift tube layers. The performance
of the HERA-B Outer Tracker system fullfilled all requirements for stable and
efficient operation in a hadronic environment, thus confirming the adequacy of
the honeycomb drift tube technology and of the front-end readout system. The
detector was stably operated with a gas gain of 30000 in an Ar/CF4/CO2
(65:30:5) gas mixture, yielding a good efficiency for triggering and track
reconstruction, larger than 95 % for tracks with momenta above 5 GeV/c. The hit
resolution of the drift cells was 300 to 320 micrometers and the relative
momentum resolution can be described as: sigma(p)/p (in %) = (1.61 +- 0.02) +
(0.0051 +- 0.0006) p. At the end of the HERA-B running no aging effects in the
Outer Tracker cells were observed.Comment: 38 pages, 20 figures. v2: Added clarifications about trigger
efficiency, momentum resolution and alignment precision. Corrected typos.
Improved figure qualit