arXiv subjects
Publications and source records attributed to V. A. Abramovsky.
We rise the question about a role of AGK theorem in QCD. Considering multiple-gluons emissions in a scattering process, we formulate the AGK-like rules of calculation of exclusive gluon distributions. The result shows that the naive extrapolation of the soft AGK, based on the pomeron idea, is not constructive and one should find a more generalized formulation.
Hadrons production is different in $p\bar{p}$ and $pp$ interactions at high energies. There is process of hadrons production from three quark strings in $p\bar{p}$ which is absent in $pp$. This process grows as $(\ln\sqrt{s})^2$ and becomes significant when energy of collision increases. Inclusive cross sections of $p\bar{p}$ interaction exceed inclusive cross sections of $pp$. Theoretical estimation of the ratio of $p\bar{p}$ to $pp$ at energy $\sqrt{s}=900$ GeV gives $R=1.12\pm0.03$. The UA1 data on $p\bar{p}$ transverse momentum distribution are about 1.2 -- 1.3 times higher than the CMS, ATLAS and ALICE data on $pp$ at energy $\sqrt{s}=900$ GeV.
We show that analysis of nonrelativistic neutron-proton scattering in a framework of relativistic QCD based quark model can give important information about QCD vacuum structure. In this model we describe total cross section of neutron-proton scattering at kinetic energies of projectile neutron from 1 eV up to 1 MeV.
We have predicted the difference in inclusive cross sections on pseudorapidity in ${\rm d}σ^{p\bar{p}}/{\rm d}η$ and ${\rm d}σ^{pp}/{\rm d}η$ interactions at $\sqrt{s}=900$~GeV. Their ratio $R=\left({\rm d}σ^{p\bar{p}}/{\rm d}η\right)\left/\left({\rm d}σ^{pp}/{\rm d}η\right)\right.>1$ in the whole pseudorapidity range. On the basis of AGK theorem we show that the ratio of inclusive cross sections of $pp$ and $p\bar{p}$ at $\sqrt{s}=900$~GeV in the region of low transverse momenta $p_\perp$ up to 2~GeV $\left(\frac{1}{2πp_\perp}\frac{{\rm d}^2σ^{p\bar{p}}}{{\rm d}η{\rm d}p_\perp}\right)\left/\left(\frac{1}{2πp_\perp}\frac{{\rm d}^2σ^{pp}}{{\rm d}η{\rm d}p_\perp}\right)\right.=R$. Experimental measurements by the ATLAS Coll. give value $R\simeq1.2$ for interval $|η|<2.5$. The difference in inclusive cross sections results from presence of additional subprocess in $p\bar{p}$ -- hadrons production from decay of three quark strings, which is absent in $pp$ scattering.
One-to-one correspondence between dual diagrams of dual resonance model and QCD based color diagrams describing non vacuum exchanges in pi+ pi-, pi+- p, p anti p interactions is discussed. Both for dual and color diagrams there are state with quark-antiquark in t channel and state, in which only coherent quark string exists, in s channel. There are no such dual diagrams in pp interaction. Color diagram for pp interaction was found basing on principle of conformity. Secondary hadrons spectrum, obtained from this diagram, has nucleon in its central region. This effect may lead to increase of baryon chemical potential in nucleus-nucleus collisions in facilities NICA and FAIR.
We consider QCD based model of hadrons interaction in which gluons density in wave function of initial state is low in rapidity space and real hadrons are produced by decay of color field strings. Hadrons production processes in pp and p antip interactions differ on principle. There are three types of inelastic processes in p antip collision. The first type is production of secondary hadrons shower from decay of gluon string. The second type is shower produced from decay of two quark strings and the third one -- from decay of three quark strings. At the same time there are only two types of inelastic processes for pp collision, they are shower from gluon string and shower from two quark strings. Therefore multiplicity distributions and inclusive spectra of secondary hadrons are different in pp and p antip interactions, and this difference may be observed at energy sqrt(s)=900 GeV.
Hadrons interaction at high energies is carried out by one color gluon exchange. All quarks and gluons contained in colliding hadrons take part in interaction and production of particles. The contribution of multiple parton interactions is negligible. Multiple hadrons production at high energies occurs only in three types of processes. The first process is hadrons production in gluon string, the second is hadrons production in two quark strings and the third is hadrons production in three quark strings. In proton-proton interaction production of only gluon string and two quark strings is possible. In proton-antiproton interaction production of gluon string, two quark strings and three quark strings is possible. Therefore multiplicity distributions in proton-proton and proton-antiproton interactions are different.
The multiple production processes of secondary hadrons in proton-antiproton scattering are divided into three types. The first type is a shower of secondary hadrons produced from gluon string decay, the second type is a shower of secondary hadrons produced from two quark strings decay and the third is a shower produced from three quark strings decay. At the same time there are only two types for proton-proton scattering - shower from gluon string and shower from two quark strings. These showers do not correspond to pomeron showers originating from cuts of one, two, three, ... pomerons. Multiplicity distribution in gluon string is Gaussian, in two and three quark strings it is negative binomial. Gluon string weight in the multiplicity distribution is determined by the constant contribution to total cross sections, the quark strings weights - by the growing with energy contributions. The expected value of proton-proton scattering total cross section and the multiplicity distribution at energy 14 TeV are given
The charged particles multiplicity distribution in the KNO form is discussed in processes of $e^+e^-$ annihilation at energies $\sqrt{s}$ 14 -- 206.2 GeV. The experimental data are compared to data, obtained with Monte Carlo simulation in PYTHIA in the Lund quark string model. It is shown, that both experimental and simulated data are described by the same distribution function in the KNO form. It is shown, that the KNO scaling is consequence of quark string hadronization dynamics in the Lund string model.
In this paper we calculate dipole amplitude and dipole amplitude correlations using first and second equation from Balitsky-Kovchegov hierarchy. Our analysis shows that even in presence of weak dipole correlation in initial condition mean field approximation breaks down through evolution. This difference asymptotically grows not only by absolute value but also by relative difference of dipole correlation from mean field value. This could affect physical values related to dipole correlation such as elliptic flow $v_2$ and 'back-forward' asymmetry in saturation model.
In this work we consider two ways to improve signal to background cross-sections ratio for higgs searchings at LHC: likelyhood method and advanced rapidity trigger. Both methods are universal enough, likelyhood method can be applied to any processes with many observables, and advanced rapidity trigger can separate any colourless scattering processes and processes with colour charge at $t$ channel.
In this work we analyse applicability of regge-based models to hadron interactions. Commonly-used extensions of pure regge model are found to be failed. Low constituent model is inroduced and found to be consistent with hadron-hadron and hadron-photon data.
Nubmer of physically interesting processes is charachterized by the rapidity gaps. In reality, this gaps is filled by uderlying events with high (more than 0.75 for higgs) probability. In this paper we purpose a way to detect this shadowed events with aim to raise the number of rare events.
In this paper we consider Cronin momentum behaviour for $p+A$, $d+A$ and $A+A$ collisions in saturation model. Our analysis shows that Cronin momentum behavior at different rapidities and energies, can be related with scaling law using simple dimensional consideration. Using exact numerical solution of Balitsky-Kovchegov equation we show that although this dependence is slightly different for McLerran-Venugopalan and Balitsky-Kovchegov definition of gluon distribution function in simple model in this case dependencies is almost the same (i.e ratio of Cronin momentum calculated using these gluon distribution functions is big constant). This can be used to experimentally distinguish this two variant of gluon distribution function definition in saturation model and choose the right one.
In this paper we applicate eikonalization procedure to the processes of elastic scattering at high energies. We have shown, that elastic data is consistent with relatively low values of eikonal parameter $c_p < 1$ only. It is in contrast with theoretical considerations.
In this work we calculate pomeron flux in the single diffraction processes. We consider two models: quasi-eikonal model and low constituent model. Both models give the pictures different from the traditional three-reggeon model. Successive developing of modeles gives some indications, that the low constituent model is more attractive.
Single diffraction processes was usually treated in the triple-reggeon framework, but this formalism is inconsistent with CDF data. In this paper we show, that multipomeron quasi-eikonal model gives agreement with these data. Cross-section of single diffraction processes at LHC energy is estimated.
The CKMT model describing the nucleon structure function $F_2(x,Q^2)$ in the framework of conventional Regge theory with smooth soft-hard pomeron is modified. Smooth soft-hard non-vacuum reggeon dependence on incoming photon virtuality $Q^2$ is introduced. This dependence has the same functional form as the smooth soft-hard functional $Q^2$ dependence for pomeron in original CKMT model. In regeon of low $W^2$ better agreement with experimental data is observed.