12 research outputs found
Accurate Measurement of F2d/F2p and Rd-Rp
Results are presented for F2d/F2p and Rd-Rp from simultaneous measurements of
deep inelastic muon scattering on hydrogen and deuterium targets, at 90, 120,
200 and 280 GeV. The difference Rd-Rp, determined in the range 0.002<x<0.4 at
an average Q^2 of 5 GeV^2, is compatible with zero. The x and Q^2 dependence of
F2d/F2p was measured in the kinematic range 0.001<x<0.8 and 0.1<Q^2<145 GeV^2
with small statistical and systematic errors. For x>0.1 the ratio decreases
with Q^2.Comment: 29 pages, LateX, including figures, prepared with uufiles, arriving
with .sty files as used, figures .eps files and a table .tex file. Accepted
for publication in Nucl.Phys.B 199
Evolution of GPR regulation in the control of spindle positioning for two Caenorhabditis species embryos
International audienceno abstrac
Extended self similarity of passive scalar in Rayleigh-Bénard convection flow based on wavelet transform
Orientation dependence of β1 → β1′ stress-induced martensitic transformation in a Cu-AI-Ni alloy
Extraction of the Gluon Density of the Proton At X
The gluon momentum density xg(x, Q(2)) of the proton was extracted at Q(2) = 20 GeV2 for small values of x between 4 x 10(-4) and 10(-2) from the scaling violations of the proton structure function F-2 measured recently by ZEUS in deep inelastic neutral current ep scattering at HERA. The extraction was performed in two ways. Firstly, using a global NLO fit to the ZEUS data on F-2 at low x constrained by measurements from NMC at larger x; and secondly using published approximate methods for the solution of the GLAP QCD evolution equations. Consistent results are obtained. A substantial increase of the gluon density is found at small x in comparison with the NMC result obtained at larger values of x
Elastic electroproduction of rho0 and J / psi mesons at large q**2 at HERA
The total cross sections for the elastic electroproduction of \rh0 and
mesons for 8 GeV and GeV/c are
measured at HERA with the H1 detector. The measurements are for an integrated
electronproton luminosity of ~3~pb. The dependences of the
total virtual photonproton () cross sections on , and
the momentum transfer squared to the proton (), and, for the , the
dependence on the polar decay angle (), are presented. The
: \rh0 cross section ratio is determined. The results are discussed
in the light of theoretical models and of the interplay of hard and soft
physics processes.Comment: 29 pages, latex, 7 Figures appended as uuencoded fil
Bose-Einstein correlations of charged and neutral kaons in deep inelastic scattering at HERA
EXTRACTION OF THE GLUON DENSITY OF THE PROTON AT X RID B-9165-2008 RID C-5889-2009 RID A-4818-2008 RID C-1693-2008
The gluon momentum density xg(x, Q(2)) of the proton was extracted at Q(2) = 20 GeV2 for small values of x between 4 x 10(-4) and 10(-2) from the scaling violations of the proton structure function F-2 measured recently by ZEUS in deep inelastic neutral current ep scattering at HERA. The extraction was performed in two ways. Firstly, using a global NLO fit to the ZEUS data on F-2 at low x constrained by measurements from NMC at larger x; and secondly using published approximate methods for the solution of the GLAP QCD evolution equations. Consistent results are obtained. A substantial increase of the gluon density is found at small x in comparison with the NMC result obtained at larger values of x