Related papers: Contact Interactions, Large Extra Dimensions and L…
The sensitivity of LeHC to different models of "new physics" has been studied, both for the resonance production and in the contact interaction approximation. Expected limits are compared for different running scenarios. Direct leptoquark…
Leptoquark searches are considered for future experiments at HERA, Tevatron, LHC, TESLA and THERA. Expected exclusion limits from direct leptoquark searches (leptoquark pair production and single leptoquark production) are compared with…
Data from HERA, LEP and the Tevatron, as well as from low energy experiments are used to constrain the scale of possible electron-quark contact interactions. Some models are found to describe the existing experimental data much better than…
Deep-inelastic e^\pm p scattering at high squared momentum transfer Q^2 up to 30000 GeV^2 is used to search for eq contact interactions associated to scales far beyond the HERA centre of mass energy. The neutral current cross section…
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…
A search for physics beyond the Standard Model in neutral current deep inelastic scattering at high negative four-momentum transfer squared Q^2 is performed in e^{\pm}p collisions at HERA. The differential cross section ds/dQ^2, measured…
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…
A search for physics beyond the Standard Model has been performed with high-Q^2 neutral current deep inelastic scattering events recorded with the ZEUS detector at HERA. Two data sets, e^+ p \to e^+ X and e^- p \to e^- X, with respective…
Measurement of the Yukawa couplings of the first-generation leptoquarks has been studied for e+e- collisions at TESLA, at sqrt(s)=800 GeV. By combining measurements from different production and decay channels, determination of Yukawa…
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…
High-precision HERA data corresponding to a luminosity of around 1 fb$^{-1}$ have been used in the framework of $eeqq$ contact interactions (CI) to set limits on possible high-energy contributions beyond the Standard Model to electron-quark…
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…
We consider lepton-quark contact interactions in models with right-handed neutrinos, and find that observational data from SN1987A restricts the scale of such interactions to be at least $\Lambda>90$ TeV.
In a search for signatures of physics processes beyond the Standard Model, various eeqq vector contact interaction hypotheses have been tested in the ZEUS experiment. No significant evidence of a contact interaction signal has been found.…
Data from HERA, LEP and the Tevatron, as well as from low energy experiments are used to constrain the scale of possible electron-quark contact interactions. Different models are considered, including the most general one, in which all new…
Data from HERA, LEP and the Tevatron, as well as from low energy experiments are used to constrain the Yukawa couplings for scalar and vector leptoquarks in the Buchmuller-Ruckl-Wyler effective model. In the limit of very high leptoquark…
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…
In a vector-like extension of the minimal standard model with mirror fermions leptoquarks can be bound states of fermion-mirror-fermion pairs held together by a new strong interaction at the TeV scale. The small couplings of leptoquarks to…
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…
The early observation at HERA of an excess of events compared to the expectation from the Standard Model in very short distance $e^+p$ deep-inelastic scattering processes has renewed the interest in the search for new physics which could…