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 $v_n$ ), for proton-proton scattering.The energy and multiplicity independence, as well as the value of $v_n$, 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 ($W > 500\, GeV$), and low energy ($W < 500\, GeV$) 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 ρ=Re/Im\rho={\rm Re/Im} 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 $W=\sqrt{s} = 30 \,GeV \div\, 13 \,TeV$ 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 $\rho$ 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 $1 mb$ 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 $\rho$ 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 $< \mid S\mid^2 >$ 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 $(\sigma_{el}+ \sigma_{SD})/\sigma_{tot}$.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 $t$ 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