Event shape analysis of deep inelastic scattering events with a large rapidity gap at HERA

A global event shape analysis of the multihadronic final states observed in neutral current deep inelastic scattering events with a large rapidity gap with respect to the proton direction is presented. The analysis is performed in the range 5 less than or equal to Q(2) less than or equal to 185 GeV(2) and 160 less than or equal to W less than or equal to 250 GeV, where Q(2) is the virtuality of the photon and W is the virtual-photon proton centre of mass energy. Particular emphasis is placed on the dependence of the shape variables, measured in the gamma*-pomeron rest frame, on the mass of the hadronic final state, M(X). With increasing M(X) the multihadronic final state becomes more collimated and planar. The experimental results are compared with several models which attempt to describe diffractive events. The broadening effects exhibited by the data require in these models a significant gluon component of the pomeron. (C) 1998 Elsevier Science B.V. RI De Pasquale, Salvatore/B-9165-2008; Wing, Matthew/C-2169-2008; Bashkirov, Vladimir/A-4818-2008; Doyle, Anthony/C-5889-2009; Gladilin, Leonid/B-5226-2011; Golubkov, Yury/E-1643-2012

A global event shape analysis of the multihadronic final states observed in neutral current deep inelastic scattering events with a large rapidity gap with respect to the proton direction is presented. The analysis is performed in the range 5 less than or equal to Q(2) less than or equal to 185 GeV(2) and 160 less than or equal to W less than or equal to 250 GeV, where Q(2) is the virtuality of the photon and W is the virtual-photon proton centre of mass energy. Particular emphasis is placed on the dependence of the shape variables, measured in the gamma*-pomeron rest frame, on the mass of the hadronic final state, M(X). With increasing M(X) the multihadronic final state becomes more collimated and planar. The experimental results are compared with several models which attempt to describe diffractive events. The broadening effects exhibited by the data require in these models a significant gluon component of the pomeron. (C) 1998 Elsevier Science B.V.