Inclusive transverse momentum spectra of charged particles in photoproduction events in the laboratory pseudorapidity range -1.2 < eta < 1.4 have been measured up to P-T = 8 GeV using the ZEUS detector. Diffractive and non-diffractive reactions have been selected with an average gamma p centre of mass (c.m.) energy of (W) = 180 GeV. For diffractive reactions, the p(T) spectra of the photon dissociation events have been measured in two intervals of the dissociated photon mass with mean values (M(X)) = 5 GeV and 10 GeV. The inclusive transverse momentum spectra fall exponentially in the low p(T) region. The non-diffractive data p show a pronounced high p(T) tail departing from the exponential shape. The p(T) distributions are compared to lower energy photoproduction data and to hadron-hadron collisions at a similar c.m. energy. The data are also compared to the results of a next-to-leading order QCD calculation. RI Bashkirov, Vladimir/A-4818-2008; De Pasquale, Salvatore/B-9165-2008; Lancaster, Mark/C-1693-2008; Doyle, Anthony/C-5889-2009; Gladilin, Leonid/B-5226-2011; Golubkov, Yury/E-1643-2012
INCLUSIVE TRANSVERSE-MOMENTUM DISTRIBUTIONS OF CHARGED-PARTICLES IN DIFFRACTIVE AND NON-DIFFRACTIVE PHOTOPRODUCTION AT HERA
SCHIOPPA M;TASSI, Enrico;
1995-01-01
Abstract
Inclusive transverse momentum spectra of charged particles in photoproduction events in the laboratory pseudorapidity range -1.2 < eta < 1.4 have been measured up to P-T = 8 GeV using the ZEUS detector. Diffractive and non-diffractive reactions have been selected with an average gamma p centre of mass (c.m.) energy of (W) = 180 GeV. For diffractive reactions, the p(T) spectra of the photon dissociation events have been measured in two intervals of the dissociated photon mass with mean values (M(X)) = 5 GeV and 10 GeV. The inclusive transverse momentum spectra fall exponentially in the low p(T) region. The non-diffractive data p show a pronounced high p(T) tail departing from the exponential shape. The p(T) distributions are compared to lower energy photoproduction data and to hadron-hadron collisions at a similar c.m. energy. The data are also compared to the results of a next-to-leading order QCD calculation. RI Bashkirov, Vladimir/A-4818-2008; De Pasquale, Salvatore/B-9165-2008; Lancaster, Mark/C-1693-2008; Doyle, Anthony/C-5889-2009; Gladilin, Leonid/B-5226-2011; Golubkov, Yury/E-1643-2012I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
