Related papers: Implications of a charged-current anomaly at HERA
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…
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 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 weak dipole moments of elementary fermions are calculated at the one-loop level in the framework of a renormalizable scalar leptoquark model that forbids baryon number violating processes and so is free from the strong constraints from…
The kinematic reconstruction of neutral current high Q^2 events at HERA is discussed in detail using as an example the recently published events of the H1 and ZEUS collaborations at Q^2 > 15000 GeV^2 and M > 180 GeV, which are more numerous…
Recently, several anomalies in flavor physics have been observed, and it was noticed that leptoquarks might account for the deviations from the Standard Model. In this work, we examine the effects of new physics originating from a scalar…
A search for narrow-width resonances that decay into electron+jet or neutrino+jet has been performed with the ZEUS detector at HERA operating at center-of-mass energies of 300 and 318 GeV. An integrated e+p luminosity of 114.8 pb-1 and e-p…
A search for first generation scalar and vector leptoquarks produced in ep collisions is performed by the H1 experiment at HERA. The full H1 data sample is used in the analysis, corresponding to an integrated luminosity of 446 pb^-1. No…
The ANITA experiment has seen anomalous Earth emergent showers of EeV energies which cannot be explained with Standard Model interactions. In addition, tests of lepton flavor universality in $ R(D^{(\ast)})$ and $R(K^{(\ast)})$ have shown…
Neutral and charged current deep inelastic ep scattering with longitudinally polarised lepton beams has been studied with the H1 and ZEUS detectors at HERA. The differential cross sections were measured in the range of four-momentum…
A search for scalar and vector leptoquarks coupling to first generation fermions is performed in the H1 experiment at the ep collider HERA. The analysis uses e^- p data collected in 1998 and 1999 at a centre-of-mass energy of 320 GeV,…
We examine the possibility that the high-Q^2 events seen at HERA are due to the production and decay of squarks of R-parity violating supersymmetry. The relevant R-parity violating coupling(s) is identified and shown to lie between 0.03 and…
Recent results from searches for new physics at HERA are reviewed. Exploiting the uniqueness of lepton-hadron collisions at high energy, searches are performed for electron-quark resonant states (leptoquarks or squarks in R-parity-violating…
We analyse solutions of the MHD equations around the electroweak transition taking into account the effects of the chiral anomaly. It is shown that a transition that is not of the first order has direct consequences on the evolution of the…
In this paper we show that the mixing between leptoquarks (LQ's) from different $SU(2)_l$ multiplets can generate a non-trivial Majorana mass matrix for neutrinos through one loop self energy diagrams. Such mixing can arise from gauge…
Leptoquark-Higgs interactions induce mixing between leptoquark states with different chiralities once the electro-weak symmetry is broken. In such LQ models Majorana neutrino masses are generated at 1-loop order. Here we calculate the…
If the standard model of quark interactions is supplemented by a discrete A_4 symmetry (which may be relevant for the lepton sector), the spontaneous breaking of the electroweak gauge symmetry allows arbitrary quark masses, but all mixing…
The CMS Collaboration has recently reported some excess events in final states with electrons and jets, in searches for leptoquarks and $W'$ bosons. Although these excesses may be due to some yet-to-be-understood background mismodeling, it…
We study the phenomenology of a particular leptoquark extension of the Standard Model (SM), namely the doublet-singlet scalar leptoquark extension of the SM (DSL-SM). Besides generating Majorana mass for neutrinos, these leptoquarks…
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…