13 research outputs found
HERA results on the structure of the proton
A selection of results from the H1 and ZEUS experiments at HERA are reviewed, particularly in the area of deep inelastic scattering and diffraction. Quantum chromodynamics gives a good explanation of these data down to surprisingly low values of the four-momentum transfer, . Data at smaller can be described by Regge models as well as by dipole models including parton-saturation effects. The latter can also give a unified description of many features of diffractive data
Structure functions at large x
Structure function data together with other measurements from fixed-target
deep inelastic scattering and hadron-hadron collider experiments which
contribute to our knowledge of the parton density functions are reviewed. The
inclusive cross-section measurements of neutral and charged current
interactions at HERA are presented and their impact on the parton density
functions is discussed. Future prospects for an improved knowledge of the
parton density functions at large x are briefly mentioned.Comment: Invited talk given at the workshop on ``New Trends in HERA Physics
2001'', Ringberg castle, Germany, June 17-22, 200
Regge behaviour of distribution functions and t and x-evolutions of gluon distribution function at low-x
In this paper t and x-evolutions of gluon distribution function from
Dokshitzer-Gribov-Lipatov-Altarelli-Parisi(DGLAP) evolution equation in leading
order(LO) at low-x, assuming the Regge behaviour of quark and gluon at this
limit, are presented. We compare our results of gluon distribution function
with MRST 2001, MRST 2004 and GRV '98 parameterizations and show the
compatibility of Regge behaviour of quark and gluon distribution functions with
perturbative quantum chromodynamics(PQCD) at low-x. We also discuss the
limitations of Taylor series expansion method used earlier to solve DGLAP
evolution equations, in the Regge behaviour of distribution functions.Comment: 19 pages, 7 figure
Collider Physics at HERA
From 1992 to 2007, HERA, the first electron-proton collider, operated at cms
energies of about 320 GeV and allowed the investigation of deep-inelastic and
photoproduction processes at the highest energy scales accessed thus far. This
review is an introduction to, and a summary of, the main results obtained at
HERA during its operation.Comment: A review article: 75 pages, 43 figure
The impact of intrinsic charm on the parton distribution functions
In this work, we present a new investigation about the impact of intrinsic
charm (IC) on the physical observables, in particular, on the heavy structure
function . Since IC distribution is dominant at large Bjorken variable
, normally, it is expected that it can be explored only at large . But,
by studying the correlation of the charm density in the proton with , we
are going to show that the IC component can also be effective at low . To
investigate further, we perform three QCD global analyses of parton
distribution functions (PDFs), by including the EMC data that are
recognized as clear evidence for existence of the intrinsic charm in the
proton, and also by considering the IC component. Although the fit of the EMC
data is extremely poor due to the data points with lower values, i.e. 0.05, but these analyses can give us new information about the impact of EMC
data and IC contribution on the behaviour of PDFs.Comment: I withdraw this paper since my supervisor require me to withdraw this
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