Related papers: Zooming-in on Instantons at HERA
We investigate the $e^+p \to \mu^+ X$ event with high transverse momenta observed at HERA (H1) and show that this event could be interpreted as a signature of the single production of the scalar top quark in a supersymmetric model with…
An overview of experimental results on searches for new phenomena at HERA is presented. The complementarity with searches performed at other experiments is discussed and the prospects for a discovery, using the full HERA data to be…
Inclusive jet and multijet cross sections measured in ep collisions in different kinematic regions by the H1 and ZEUS experiments are shown. The measurements are used to extract the strong coupling alpha_s as a function of the scale and at…
At HERA, the large flux of almost real photons accompanying the electron beam leads to the copious photoproduction of jets. Regions of small momentum fractions $x$ of the incoming particles are explored, where the density of partons is…
The H1 and ZEUS experiments at the HERA $e^\pm p$ collider at Hamburg have recently reported some anomalous hard-scattering events, which could be indicative of new physics beyond the standard model. I have tried to discuss in a…
Two results in ep physics using HERA data are discussed: a measurement of the effective transverse parton momentum in the proton by studying the production of prompt-photons in photoproduction events in the ZEUS collaboration and…
A review is presented of recent results in QCD from the H1 and ZEUS experiments at HERA, emphasizing the use of higher order calculations to describe the data.
The status of theoretical studies of the $H$ dibaryon is reviewed. Some recent developments including the effect of the instanton induced interaction and the QCD sum rule results are discussed in detail.
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…
A QCD fit analysis to the combined HERA inclusive deep inelastic cross sections measured by the H1 and ZEUS collaborations for $e^\pm p$ scattering to extract HERAPDF sets is presented. The results are used for predictions of $ p\bar{p}$…
The success of recently proposed models for describing rapidity-gap events in DIS at HERA, in terms additional colour exchange between the struck system and the proton remnant in boson-gluon fusion events, are found to rely heavily on the…
Analyses of jet production at HERA have become precise enough to perform QCD studies which are both competitive and complementary to those at e+e- and p-pbar colliders. This report summarises some of the latest results on jet physics from…
A variety of possible future analyses of HERA data in the context of the HERA data preservation programme is collected, motivated, and commented. The focus is placed on possible future analyses of the existing $ep$ collider data and their…
We reexamine the contact interaction hypothesis for excess high-$Q^2$ events seen at HERA in $e^+ p \to e^+ X$ scattering. We consider the most general structure of contact interactions insisting on $SU(3)_C\times SU(2)_L \times U(1)_Y$…
We discuss the possibility of explaining the excess in the cross section at high-Q^2 recently found at HERA in terms of four-fermion effective interactions. To avoid the constraints from low-energy data, we select three special cases in…
We point out that in some situations it is possible to use matrix model techniques a la Dijkgraaf-Vafa to perturbatively compute D-brane instanton effects. This provides an explanation in terms of stringy instantons of the results in…
The prospects of physics beyond the standard model in deep inelastic scattering are reviewed, emphasizing the search for contact interactions, for leptoquarks and for supersymmetry with R-parity violation. R-parity violating supersymmetry…
The energy levels of the double-well potential receive, beyond perturbation theory, contributions which are non-analytic in the coupling strength; these are related to instanton effects. For example, the separation between the energies of…
The instanton-induced multiple events in high energy collisions are considered in nonperturbative quantum chromodynamics. Here we obtained unusual behaviour of ratio of correlation moments Hq for such processes which can be used for…
Results on multi-lepton events at high transverse momenta, isolated lepton events with large missing transverse energy and single W production reported to this conference are based for the first time on the full data samples taken by two…