Related papers: Constraints on Electron-quark Contact Interactions
We perform a global analysis of the lepton-quark neutral current data on the low scale gravity model, which arises from the extra dimensions. The global data include HERA neutral current deep-inelastic scattering, Drell-yan production at…
The H1 and ZEUS collaborations at HERA have searched for signatures of physics beyond the Standard Model using high Q^2 neutral current deep inelastic electron-proton and positron-proton scattering events. No significant deviations from…
We explore the capability of the Tevatron and LHC as well as other future hadron colliders to place limits on the possible existence of flavor-independent $q \bar q \gamma\gamma$ contact interactions which can lead to an excess of high…
We present the most recent measurements on top-quark physics obtained with Tevatron $p\bar{p}$ collisions recorded by the D0 experiment at $\sqrt{s}= 1.96$ TeV. The full Run II data set of 9.7 fb$^{-1}$ is analyzed. Both lepton+jets and…
The H1 and ZEUS collaborations at HERA have searched for signatures of physics beyond the Standard Model with high Q^2 neutral current deep inelastic electron-proton and positron-proton scattering events. No significant deviations from…
We explore the capability of the Tevatron and LHC to place limits on the possible existence of flavor-independent $q \bar q \gamma\gamma$ contact interactions which can lead to an excess of diphoton events with large invariant masses.…
We derive conservative upper limits on the dark-matter--nucleon scattering cross-section for sub-GeV mass dark matter. Working exclusively within the low-energy chiral effective theory, we derive bounds that are independent of the details…
We investigate the constraints on four-Fermi contact interactions from low-energy lepton-quark and lepton-lepton scattering experiments --- polarization asymmetries in electron (muon)-nucleon scattering experiments, cesium and thallium atom…
A contact four-fermion interaction between light quarks and electrons has been evoked as a possible explanation for the excess of events observed by HERA at high-$Q^2$. We explore the 1-loop effects of such interaction in $\Gamma(Z^0 \to…
The reaction e+p --> e+X is studied with the H1 detector at Hera. The data cover momentum transfers Q^2 between 200 GeV^2 and 30,000 GeV^2 and correspond to an integrated luminosity of 35.6 pb^(-1). The differential cross section…
This Letter presents a search for contact interactions in the dielectron and dimuon channels using data from proton-proton collisions produced by the LHC at sqrt(s) = 7 TeV and recorded by the ATLAS detector. The data sample, collected in…
A complete set of dimension-6 effective contact interactions involving Higgs, gauge bosons and quarks is studied. Limits on the coefficients of these new operators are obtained from the experimental values of the $Z$ and $W$ gauge bosons…
We explore the sensitivity of Tevatron data to heavy new physics effects in differential dijet production rates using the SMEFT in light of the fact that consistent and conservative constraints from the LHC cannot cover relatively low…
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 explore the nonuniversal interaction effects in terms of the precision variables epsilons with the recent LEP data reported by the Electroweak Working Group. The epsilon variables with the nonuniversal interactions are calculated and…
We present a measurement of the electric charge of top quarks using $t\bar{t}$ events produced in $p\bar{p}$ collisions at the Tevatron. The analysis is based on fully reconstructed $t\bar{t}$ pairs in lepton+jets final states. Using data…
The high-precision HERA data allows searches up to TeV scales for Beyond the Standard Model contributions to electron-quark scattering. Combined measurements of the inclusive deep inelastic cross sections in neutral and charged current $ep$…
We explore interpretations of the anomaly observed by H1 and ZEUS at HERA in deep-inelastic e^+ p scattering at very large Q^2. We discuss the possibilities of new effective interactions and the production of a narrow state of mass 200 GeV…
We examine the phenomenological implications of a 200 GeV leptoquark in light of the recent excess of events at HERA. Given the relative predictions of events rates in e^+p versus e^-p, we demonstrate that classes of leptoquarks may be…
We present new observational constraints on the elastic scattering of dark matter with electrons for dark matter masses between 10 keV and 1 TeV. We consider scenarios in which the momentum-transfer cross section has a power-law dependence…