相关论文: Contact Terms, Compositeness, and Atomic Parity Vi…
Recent experimental results on the partonic structure of the photon and on the color singlet exchange in strong interaction processes are reviewed. At the LEP electron-positron and HERA lepton-proton colliders, complementary and consistent…
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.…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results obtained at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak…
Results are reported from a search for the effects of contact interactions using events with a high-mass, oppositely charged muon pair. The events are collected in proton-proton collisions at sqrt(s) = 7 TeV using the Compact Muon Solenoid…
A search for lepton-flavor-violating interactions $e p \to \mu X $ and $e p\to \tau X $ has been performed with the ZEUS detector using the entire HERA I data sample, corresponding to an integrated luminosity of 130 pb^{-1}. The data were…
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 $SU(3)_C\times SU(2)_L \times U(1)_Y$…
The leading weak corrections to the production of top quark pairs via $q\bar{q} \to t\bar{t}$ in $p\bar{p}$ collisions are evaluated. The chromo-anapole form factor of the top quark and effects of parity violation are studied in the…
Plenty of hadrons have been established experimentally, yet the nonperturbative nature of the strong interaction complicates a comprehensive understanding of their internal structure, particularly for exotic hadrons that extend beyond…
In theories of Partial Compositeness the top quark is a mixture of a composite and an elementary state, and as a consequence its interactions with gauge bosons are expected to deviate from those of a point-like object. At sufficiently large…
We derive empirical relationships among elementary fermion masses based on relatively simple exponential formulae involving quantum numbers for the electromagnetic and strong interactions, with a weak correction factor motivated by a simple…
A search has been made for lepton-flavor-violating interactions, e+ p -> mu/tau X, at a center-of-mass energy of 300 GeV with an integrated luminosity of 47.7 pb^-1 using the ZEUS detector at HERA. No evidence was found for lepton-flavor…
Physics from beyond the Standard Model, such as leptoquarks, can induce four fermion operators involving a quark, an anti-quark, a lepton and an anti-lepton. We update the (flavour dependent) constraints on the coefficients of such…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak…
This note presents constraints on Standard Model parameters using published and preliminary precision electroweak results measured at the electron-positron colliders LEP and SLC. The results are compared with precise electroweak…
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…
The lepton or baryon number violating top quark interactions in the supersymmetric standard model with R parity violation contribute to the process d dbar to t tbar at the tree level via the t- or u-channel sfermion exchange. Since these…
A review of searches for physics beyond the Standard Model carried out at high energy lepton-hadron and hadron-hadron facilities is presented, with emphasis on topics of interest for future data taking at the upgraded Tevatron $p{\bar p}$…
Recent results on searches for physics beyond the Standard Model obtained by the H1 and ZEUS experiments are reported here. After a brief introduction to the HERA collider, indirect searches for contact interactions and extra-dimensions are…
Events in PbarP collisions at sqrt(s)=1.8 TeV with total transverse energy exceeding 500 GeV are used to set limits on quark substructure. The data are consistent with next-to-leading order QCD calculations. We set a lower limit of 2.0 TeV…
It has been shown that CP violating electron-nucleon and nucleon-nucleon interactions can induce atomic electric dipole moments and are therefore constrained from experimental data. We show that using the experimental upper bounds on…