Related papers: Leptoquarks and Contact Interactions from a Global…
Angular and energy distributions for leptons and bottom quarks in the process e^+e^- --> t t-bar --> l^{+-}/b(b-bar) ... have been calculated assuming the most general top-quark couplings. The double distributions depend both on…
We perform a comparative study of the reach of future $e^+e^-$ collider options for the scale of non-resonant new physics effects in the top quark sector, phrased in the language of higher-dimensional operators. Our focus is on the…
We analyse the constraints on scalar leptoquarks coming from radiative corrections to $Z$ physics. We perform a global fitting to the LEP data including the contributions of the most general effective Lagrangian for scalar leptoquarks,…
Various searches for leptoquarks, scalar quarks in $R_p$-violating supersymmetric models, and excited fermions performed by the HERA experiments H1 and ZEUS are reviewed. No evidence for new particle production was observed from data…
In this report we study how a light-scalar leptoquark could affect the Higgs boson production cross-section at the LHC collider. We construct the most general renormalizable and gauge invariant effective Lagrangian involving the standard…
Neutrino-nucleus coherent scattering measurements by the COHERENT collaboration provide us with a unique capability to test various beyond the standard model scenarios. In this work, we constrain scalar leptoquarks (LQs) using the COHERENT…
We investigate to which extent an interpretation of the recently observed excess of events in the high $Q^2$ range at HERA in terms of single leptoquark production is compatible with bounds from other experiments.
For the first time the experiments ALEPH, DELPHI, L3 and OPAL have presented preliminary results for fermion-pair production in e+e- collisions on the full data set above the Z pole. A combined analysis of the Bhabha scattering measurements…
Theoretical interpretations of the high-Q^2 events recently observed in deep-inelastic positron-proton scattering at HERA are reviewed. We discuss leptoquarks, squarks with R-parity violating couplings, and contact interactions. Bounds from…
We perform a model independent analysis of the production of scalar and vector leptoquarks in the $e^-\gamma$ mode of a linear collider of the next generation. Since these leptoquarks are produced singly, higher masses can be probed than in…
A search for first generation scalar and vector leptoquarks (LQ) as well as for squarks in R-parity violating SUSY models has been performed using e+e- collisions collected with the OPAL detector at LEP at an e+e- centre-of-mass energy…
The contributions of scalar leptoquarks in lepton flavor violating (LFV) processes of type $l_i\to l_j \gamma$ are investigated in frame of the minimal model with the four color symmetry and Higgs mechanism of quark and lepton mass…
HERA is the only high energy electron-proton collider in the world today and hence has unique opportunities both to probe the structure of the proton and to search for physics beyond the Standard Model. Results are presented for…
Pair production of leptoquarks at future e+e- linear colliders is investigated for center-of-mass energies of 500 GeV and 800 GeV and an integrated luminosity of 500 fb^-1. Based on a Monte Carlo simulation we estimate the event rates for…
While the hunt for new states beyond the standard model (SM) goes on for various well motivated theories, the leptoquarks are among the most appealing scenarios at recent times due to a series of tensions observed in $B$-meson decays. We…
Fermion compositeness and other new physics can be signalled by the presence of a strong four-fermion contact interaction. Here we present a study of $\ell\ell qq$ and $\ell\ell\ell'\ell'$ contact interactions using the reactions: $\ell^+…
I report the recent studies\cite{1,2} on the low--energy manifestations of a minimal extension of the Standard Model based on the quark-lepton symmetry $SU(4)_V \otimes SU(2)_L \otimes G_R$ of the Pati-Salam type. Given this symmetry the…
Leptoquarks (LQs) are hypothetical particles that appear in various extensions of the Standard Model (SM) that can explain observed differences between SM theory predictions and experimental results. The production of these particles has…
We study limits from dilepton searches on leptoquark completions to the Standard Model in the parameter space motivated by anomalies in the $b \rightarrow s$ sector. After a full Run-2 analysis by LHCb, the disparity in lepton flavour…
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…