259 research outputs found
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
Soft interaction model and the LHC data
Most models for soft interactions which were proposed prior to the
measurements at the LHC, are only marginally compatible with LHC data, our GLM
model has the same deficiency. In this paper we investigate possible causes of
the problem, by considering separate fits to the high energy (),
and low energy () data. Our new results are moderately higher
than our previous predictions. Our results for total and elastic cross sections
are systematically lower that the recent Totem and Alice published values,
while our results for the inelastic and forward slope agree with the data. If
with additional experimental data, the errors are reduced, while the central
cross section values remain unchanged, we will need to reconsider the physics
on which our model is built.Comment: 12 pp, 12 figures in .eps file
Survival probability of large rapidity gaps in QCD and N=4 SYM motivated model
In this paper we present a self consistent theoretical approach for the
calculation of the Survival Probability for central dijet production . These
calculations are performed in a model of high energy soft interactions based on
two ingredients:(i) the results of N=4 SYM, which at the moment is the only
theory that is able to deal with a large coupling constant; and (ii) the
required matching with high energy QCD. Assuming, in accordance with these
prerequisites, that soft Pomeron intercept is rather large and the slope of the
Pomeron trajectory is equal to zero, we derive analytical formulae that sum
both enhanced and semi-enhanced diagrams for elastic and diffractive
amplitudes. Using parameters obtained from a fit to the available experimental
data, we calculate the Survival Probability for central dijet production at
energies accessible at the LHC. The results presented here which include the
contribution of semi-enhanced and net diagrams, are considerably larger than
our previous estimates.Comment: 11 pages, 10 pictures in .eps file
CGC/saturation approach: secondary Reggeons and dependence on energy
In this letter we demonstrate that a model which is based on the
CGC/saturation approach, is able to describe soft interaction collisions for
the wide range of including the new
TOTEM data at 13 TeV. We have incorporated the secondary Reggeons in our
approach which enables us to describe the complete set of the soft data,
including the energy behaviour of the ratio of the real to imaginary
parts of the elastic scattering amplitude. We argue that it is premature to
claim that an odderon contribution is necessary, but estimate its possible
strength as to the real part of the amplitude at W = 13 \,TeV. We show
that the odderon contribution depends on the value of energy leading to {\rm
Re A\Lb s, t=0\Rb} = 8 mb at W=21.2 \,GeV. Bearing this in mind we do not
believe that at high energies is the appropriate observable for
detecting the odderon contribution. The successful description of the soft data
in the wide range of energy strengthens our claim that the CGC/saturation
approach is the only viable candidate for an effective theory for high energy
QCD.Comment: 6pp. 5 figures in pdf files. arXiv admin note: text overlap with
arXiv:1712.06992, arXiv:1706.07617, arXiv:1607.0059
A new parton model for the soft interactions at high energies
We propose a new parton model and demonstrate that the model describes the
relevant experimental data at high energies. The model is based on Pomeron
calculus in 1+1 space-time dimensions, as suggested in Ref. [18] and on simple
assumptions regarding the hadron structure, related to the impact parameter
dependence of the scattering amplitude. This parton model evolves from QCD,
assuming that the unknown non-perturbative corrections lead to fixing size of
the interacting dipoles. The advantage of this approach is that it satisfies
both t-channel and s-channel unitarity, and can be used for summing all
diagrams of Pomeron interactions, including Pomeron loops. We can use this
approach for all reactions: dilute-dilute (hadron-hadron), dilute-dense
(hadron-nucleus) and dense-dense (nucleus-nucleus)for the scattering of parton
systems. Unfortunately, we are still far from being able to tackle this problem
in the effective QCD theory at high energy (i.e. in the CGC /saturation
approach).Comment: 12 pp. with 5 figures in eps file
The survival probability of large rapidity gaps in a three channel model
The values and energy dependence for the survival probability of large rapidity gaps (LRG) are calculated in a three channel model. This
model includes single and double diffractive production, as well as elastic
rescattering. It is shown that decreases with increasing
energy, in line with recent results for LRG dijet production at the Tevatron.
This is in spite of the weak dependence on energy of the ratio .Comment: 26 pages in latex file,11 figures in eps file
A QCD motivated model for soft interactions at high energies
In this paper we develop an approach to soft scattering processes at high
energies,which is based on two mechanisms: Good-Walker mechanism for low mass
diffractionand multi-Pomeron interactions for high mass diffraction. The
pricipal idea, that allows us to specify the theory for Pomeron interactions,
is that the so called soft processes occur at rather short distances
(r^2 \propto 1 /^2 \propto \alpha'_\pom \approx 0.01 GeV^{-2}), where
perturbative QCD is valid. The value of the Pomeron slope \alpha'_\pom was
obtained from the fit to experimental data. Using this theoretical approach we
suggest a model that fits all soft data in the ISR-Tevatron energy range, the
total, elastic, single and double diffractive cross sections, including
dependence of the differential elastic cross section, and the mass dependence
of single diffraction. In this model we calculate the survival probability of
diffractive Higgs production, and obtained a value for this observable, which
is smaller than 1% at the LHC energy range.Comment: 33pp,20 figures in eps file
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