Related papers: A Test of SU(15) at HERA Using The HELAS Program
By using a Regge-pole model for vector meson production (VMP), successfully describing the HERA data, we analyse the correlation between VMP cross sections in photon-induced reactions at HERA and those in ultra-peripheral collisions at the…
Recent data obtained in ep collisions at HERA by the H1 collaboration are presented: searches for new phenomena beyond the Standard Model, measurement of the inclusive neutral and charged current cross sections and of the proton structure…
Triple differential dijet cross-sections in e p interactions measured with the H1 and ZEUS detectors at HERA are presented. The data are compared to Monte Carlo simulations which differ in their assumptions about photon structure and parton…
The photon-proton total cross section has been measured in the process e+ p -> e+ gamma p -> e+ X with the ZEUS detector at HERA. Events were collected with photon virtuality Q^2 < 0.02 GeV^2 and average gamma-p center-of-mass energy…
We propose a simple, testable, SU(5) model within the context of the type II neutrino see-saw mechanism. It is based on requiring renormalizability, the absence of any other matter fields besides those already present in the Standard Model…
Measurements of the structure of the virtual photon in the transition region between quasi-real photons and those far from mass-shell have been made with the ZEUS detector at HERA, using an integrated luminosity of 38pb-1. Dijet final…
We describe a pion physics program attainable with the CERN COMPASS spectrometer, involving tracking detectors and an electromagnetic calorimeter. COMPASS can realize state-of-the-art pion beam hybrid meson and meson radiative transition…
A search for events with an isolated high-energy lepton and large missing transverse momentum has been performed with the ZEUS detector at HERA using a total integrated luminosity of 504 $\mathrm{pb}^{-1}$. The results agree well with…
The measurement and QCD analysis of neutral and charged current cross sections at HERA are presented. For the kinematic range of four-momentum transfer Q^2 between approx. 1 GeV^2 and 30000 GeV^2 and Bjorken x between 0.0013 and 0.65 the…
A survey is presented of the various processes measurable at HERA in which two photons are involved. Their current experimental status and future prospects are discussed.
Heavy quarks are copiously produced in two-photon collisions at $e^+e^-$ colliders. The theoretical predictions including QCD radiative corrections are compared to recent experimental data on $\gamma\gamma$ production of charm quarks at…
We investigate an event excess in the reaction $e^+p \to e^+ X$ with large $x$ and high $Q^2$ observed at HERA and show that the events could naturally be interpreted as a signature of the production of the scalar top quarks (stops) in a…
We show how the Higgs boson exchange processes may indicate the occurence of special Higgs boson structures (substructures or peculiar interactions with dark matter) from a possible modification of the s-dependence of their cross section.…
The measurement of the polarized gluon distribution function $\Delta g(x)$ from photon gluon fusion processes in electron proton deep inelastic scattering producing two jets has been investigated. The study is based on the MEPJET simulation…
We show that photoproduction cross sections recently measured by ZEUS and H-1 at HERA energies$^1$ are in agreement with our earlier prediction based on high-energy hadronic structure of the photon in the QCD minijet-type model$^2$. We…
Recent ZEUS measurements of inclusive-jet and dijet cross sections in neutral current deep inelastic ep scattering at HERA are presented. The data correspond to more than a two-fold increase in statistics compared to previous studies. The…
Recent results from HERA are presented on a range of topics: charged multiplicities, production of non-strange mesons and strange particles, charm fragmentation, baryons decaying to strange particles, antideuteron production, Bose-Einstein…
In order to explain a striking symmetry of the HERA data for virtual photon-proton cross section, I propose a simple model based on the elementary 2-gluon exchange dipole-dipole cross section, and which exhibits geometric scaling. I also…
HERA-B is a hadroproduction experiment located at DESY in Hamburg, Germany. The experiment produces B mesons and baryons by inserting thin wire targets into the halo of the proton beam circulating in the HERA storage ring. The B decays are…
We explore QCD calculations for the process gamma p -> V X where V is a vector meson, in the region s >> -t and -t >> Lambda_QCD^2. We compare our calculations for the J/psi, phi and rho mesons with data from the ZEUS Collaboration at HERA…