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K. Golec-Biernat

Publications and source records attributed to K. Golec-Biernat.

47 records · Page 3Linked to original sources
arXiv1998

Saturation Effects in Deep Inelastic Scattering at low $Q^2$ and its Implications on Diffraction

We present a model based on the concept of saturation for small $Q^2$ and small $x$. With only three parameters we achieve a good description of all Deep Inelastic Scattering data below $x=0.01$. This includes a consistent treatment of charm and a successful extrapolation into the photoproduction regime. The same model leads to a roughly constant ratio of diffractive and inclusive cross section.

hep-ph↗
arXiv1998

Diffractive dijet photoproduction as a probe of the off-diagonal gluon distribution

We propose exclusive diffractive dijet photoproduction as an ideal measure of the off-diagonal gluon distribution at high scales. We solve the off-diagonal evolution equations for the gluon and quark singlet over the full kinematic domain. We discuss the nature of the solutions of these equations, which embody both DGLAP and ERBL evolution. We give predictions for the transverse momentum distribution of the jets. In particular we quantify the enhancement arising from the evolution of the off-diagonal parton distributions.

hep-ph↗
arXiv1998

QCD coherence in deep inelastic scattering at small x at HERA

QCD coherence effects in initial state radiation at small x in deep inelastic scattering in HERA kinematics are studied with the help of the Monte Carlo model SMALLX. Theoretical assumptions based on the CCFM evolution equation are reviewed and the basic properties of the partonic final states are investigated. The results are compared with those obtained in the conventional DGLAP evolution scheme.

hep-ph↗
arXiv1997

Reggeons in diffractive interactions in deep inelastic scattering at HERA

The "triple-Regge" analysis of subleading Reggeon contributions to the diffractive structure function in DIS at HERA is presented. The recently published data allow to estimate the only free parameter of the analysis related to the ratio of the RRP and PPP couplings. The large value of this ratio is prefered which is in agreement with analyses of soft hadronic interactions. The role of the subleading Reggeons as well as pions for the fast forward neutron production in diffractive processes is estimated. The forward piN state production is also discussed.

hep-ph↗
arXiv1997

Reggeon and pion contributions in semi-exclusive diffractive processes at HERA

A detailed analysis of semi-exclusive diffractive processes in e-p DIS at HERA, with the diffractive final states in the forward direction is presented. The contributions of the subleading f_2, ω, a_2, ρreggeons and the pion exchanges to the diffractive structure function with the forward proton or neutron are estimated. It is found that the (a_2,ρ) reggeons are entirely responsible for the forward neutron production at x_P < 10^{-3}. The πN production in the forward region is estimated using the Deck mechanism. The significance of this reaction for the processes measured at HERA, especially with the leading neutron, is discussed.

hep-ph↗
arXiv1996

Subleading Reggeons in Deep Inelastic Diffractive Scattering at HERA

The contribution of subleading reggeons to the diffractive structure function ${dF_{2}^D / dx_{\funp} dt}$ is estimated from the soft physics data. This contribution leads in a natural way to the violation of the factorization property of the diffractive structure function.

hep-ph↗
arXiv1996

QCD: Quantum Chromodynamic Diffraction

The first measurements of the diffractive structure function $F_2^{D(3)}$ at HERA are discussed. A factorisable interpretation in which a partonic structure is assigned to the pomeron is investigated through QCD analyses in which both the quark and gluon densities are permitted to vary freely. A method of measuring the longitudinal structure function of the pomeron without changing the $ep$ centre of mass energy is presented. The possibility that the pomeron structure may receive a large contribution from gluons, relative to quarks, at high $β$ is highlighted, and the experimental signatures which may support such a structure are reviewed.

hep-ph↗
arXiv1995

QCD Analysis of Deep Inelastic Diffractive Scattering at HERA

The QCD analysis of deep inelastic diffractive scattering is performed assuming the dominance of the "soft" pomeron exchange and simple, physically motivated parametrization of parton distributions in a pomeron. Results of the analysis are compared with the recent data obtained by the H1 collaboration at HERA. Both the LO and NLO approximations are considered and the theoretical predictions concerning the quantity $R=F_L^D/F_T^D$ for diffractive structure functions are presented.

hep-ph↗
arXiv1994

Transverse Energy Flow at HERA

We calculate the transverse energy flow accompanying small $x$ deep-inelastic events and compare with recent data obtained at HERA. In the central region between the current jet and the remnants of the proton we find that BFKL leading $\ln(1/x)$ dynamics gives a distinctively large transverse energy distribution, in approximate agreement with recent data.

hep-ph↗
arXiv1994

QCD Predictions for the Transverse Energy Flow in Deep-Inelastic Scattering in the Small x HERA Regime

The distribution of transverse energy, $E_T$, which accompanies deep-inelastic electron-proton scattering at small $x$, is predicted in the central region away from the current jet and proton remnants. We use BFKL dynamics, which arises from the summation of multiple gluon emissions at small $x$, to derive an analytic expression for the $E_T$ flow. One interesting feature is an $x^{-ε}$ increase of the $E_T$ distribution with decreasing $x$, where $ε= (3α_s/π)2\log 2$. We perform a numerical study to examine the possibility of using characteristics of the $E_T$ distribution as a means of identifying BFKL dynamics at HERA.

hep-ph↗