21,242 research outputs found
Coulomb Glasses: A Comparison Between Mean Field and Monte Carlo Results
Recently a local mean field theory for both eqilibrium and transport
properties of the Coulomb glass was proposed [A. Amir et al., Phys. Rev. B 77,
165207 (2008); 80, 245214 (2009)]. We compare the predictions of this theory to
the results of dynamic Monte Carlo simulations. In a thermal equilibrium state
we compare the density of states and the occupation probabilities. We also
study the transition rates between different states and find that the mean
field rates underestimate a certain class of important transitions. We propose
modified rates to be used in the mean field approach which take into account
correlations at the minimal level in the sense that transitions are only to
take place from an occupied to an empty site. We show that this modification
accounts for most of the difference between the mean field and Monte Carlo
rates. The linear response conductance is shown to exhibit the Efros-Shklovskii
behaviour in both the mean field and Monte Carlo approaches, but the mean field
method strongly underestimates the current at low temperatures. When using the
modified rates better agreement is achieved
A CGC/saturation approach for angular correlations in proton-proton scattering
We generalized our model for the description of hard processes, and calculate
the value of the azimuthal angle correlations ( Fourier harmonics ), for
proton-proton scattering.The energy and multiplicity independence, as well as
the value of , turn out the be in accord with the experimental data, or
slightly larger.
Therefore, before making extreme assumptions on proton-proton collisions,
such as the production of quark-gluon plasma in the large multiplicity events,
we need to explain how these effect theBose-Einstein correlations which are so
large, that have to be taken into account, and which are able to describe the
angular correlations in proton-proton collisions, without including final state
interactionsComment: 26 pp. 17 figures in eps file
CGC/saturation approach: soft interaction at the LHC energies
In this paper we demonstrate that our model which is based on the
CGC/saturation approach, is able to describe the soft interaction collisions
including the new TOTEM prelimenary data at 13 TeV. We believe that this
strengthens the argument that the CGC/saturation approach is the only viable
candidate for an effective theory for high energy QCD.Comment: 6pp,4 figures. arXiv admin note: substantial text overlap with
arXiv:1706.07617, arXiv:1607.0059
Production of q bar-q Pairs in Proton-Nucleus Collisions at High Energies
We calculate production of quark-antiquark pairs in high energy
proton-nucleus collisions both in the quasi-classical approximation of
McLerran-Venugopalan model and including quantum small- evolution. The
resulting production cross section is explicitly expressed in terms of
Glauber-Mueller multiple rescatterings in the classical case and in terms of
dipole-nucleus scattering amplitude in the quantum evolution case. We
generalize the result of one of us (K.T.) beyond the aligned jet
configurations. We expand on the earlier results of Blaizot, Gelis and
Venugopalan by deriving quark production cross section including quantum
evolution corrections in rapidity intervals both between the quarks and the
target and between the quarks and the projectile.Comment: 18 pages, 3 figures; typos corrected, discussion extende
Properties of inclusive hadron production in Deep Inelastic Scattering on heavy nuclei at low x
In this paper we present a comprehensive study of inclusive hadron production
in DIS at low . Properties of the hadron spectrum are different in different
kinematic regions formed by three relevant momentum scales: photon virtuality
, hadron transverse momentum and the saturation momentum .
We investigate each kinematic region and derive the corresponding asymptotic
formulas for the cross section at the leading logarithmic order. We also
analyze the next-leading-order (NLO) corrections to the BFKL kernel that are
responsible for the momentum conservation. In particular, we establish the
asymptotic behavior of the forward elastic dipole--nucleus scattering amplitude
at high energies deeply in the saturation regime and a modification of the
pomeron intercept. We study the nuclear effect on the inclusive cross section
using the nuclear modification factor and its logarithmic derivative. We argue
that the later is proportional to the difference between the anomalous
dimension of the gluon distribution in nucleus and in proton and thus is a
direct measure of the coherence effects. To augment our arguments and present
quantitative results we performed numerical calculations in the kinematic
region that may be accessible by the future DIS experiments.Comment: 29 pages, 8 figure
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