Related papers: S, T, and Leptoquarks at HERA
We extend the contents of the standard model (SM) by introducing TeV-scale scalar leptoquarks to generate neutrino masses and explain some current observed deviations from the SM predictions, including the anomalous magnetic moments of…
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 effects of Scalar Leptoquarks in various channels have been analysed for the HERA collider and also for an eventual new $ep$ machine running at higher energies. We emphasize the relevance of polarized beams.
A colored weak singlet scalar state with hypercharge 4/3 is one of the possible candidates for the explanation of the unexpectedly large forward-backward asymmetry in t tbar production as measured by the CDF and D0 experiments. We…
The cross sections for the formation of scalar resonances, leptoquarks or squarks, in electron/positron-proton collisions at HERA are presented including next-to-leading order QCD corrections. Depending mildly on the mass of the resonances,…
The latest results from the H1 and ZEUS collaborations are presented on leptoquark production and rare Standard Model processes. The data were taken in the period 1994-2005, at a centre of mass energy of up to 319 GeV. Intriguing events…
Recent results on hard diffraction at HERA and the Tevatron are presented. Charged particle multiplicities in diffraction and differences in multiplicity in quark and gluon jets measured at LEP are discussed. Spin effects in the…
An interpretation that the HERA excess events are due to intermediate production and decay of composite leptoquarks in the left-right symmetric preon model is given. Because of the preon-line rule, expected to be valid well, the event-ratio…
We show that the angular distributions of leptons or jets due to ttbar spin correlations allow a determination of the top chromomagnetic moment kappa with an accuracy of order 0.1. The method is quite insensitive to background, event…
The search and the identification of Scalar Leptoquarks are analyzed for the HERA collider. We emphasize the relevance of having polarized beams and we make some remarks on the usefulness of en collisions.
This article summarizes the status of the Tevatron Run II searches for leptoquarks in $p\bar{p}$ collisions at $\sqrt{s}=1.96 $ TeV. The analyses discussed use datasets with integrated luminosities ranging from 72 pb$^{-1}$ to 200…
The dynamical diquark model describes multiquark exotic hadrons in terms of diquark components nucleated by heavy quarks, and successfully explains multiple features of hidden-charm and -bottom exotics. Here we apply the model to the…
A contact interaction analysis is presented to search for new phenomena beyond the Standard Model in deep inelastic $e^\pm p \rightarrow e^\pm \, hadrons$ scattering. The data are collected with the H1 detector at HERA and correspond to…
The Standard Model is extended by a SU(2)L singlet of vector leptoquarks. An additional SU(4) gauge symmetry between right-handed up quarks and right-handed leptons is introduced to render the model renormalizable. The arrangement is made…
We perform a systematic analysis of scalar and vector leptoquark pair production at the Fermilab Tevatron and at the CERN LHC. We evaluate signal expectations and background levels for the processes pp (p ppar) -> 2 jets + e^{+} + e^{-} and…
Events with an isolated high $p_T$ lepton, a hadron jet and missing energy as observed in the H1 experiment at HERA, are potentially associated with R-parity violation in supersymmetric theories. However, stringent kinematic constraints…
I report here on the systematic analysis at Tevatron of the R-parity violating SUSY signals which correspond to the possible solution of anomalous HERA events.
A search for scalar and vector leptoquarks coupling to first generation fermions is performed using the e^+p and e^-p scattering data collected by the H1 experiment between 1994 and 2000. The data correspond to a total integrated luminosity…
A search for leptoquarks at HERA was performed in H1 using 1994 $e^+ p$ data corresponding to an integrated luminosity of about $3 \pb^{-1}$. Single leptoquarks were searched for in direct positron-quark fusion processes taking into account…
We study the effects of virtual leptoquarks on charged current and neutral current processes at the $ep$ collider HERA. We present the areas of parameter space that can be excluded at HERA by searching for deviations from Standard Model…