Related papers: CERN LEP2 constraint on 4D QED having dynamically …
A conformally invariant hidden sector is considered, with a scalar operator $O$ of low dimension that couples to the electro-weak gauge bosons of the Standard Model, via terms such as $O F^{\mu\nu}F_{\mu\nu}$. By examining single photon…
We review dynamical mass generation in three and four dimensional Ableian gauge theories. The basic approach analyzed here is to solve Schwinger-Dyson equations in some approximations. In both cases, the coupling has to be larger than a…
We consider massless three-dimensional $\mathcal{N}=1$ supersymmetric quantum electrodynamics (QED) with $N_f$ flavours of electrons. Within the dimensional reduction scheme, we compute the critical exponents corresponding to both the…
A consistent description of the $ d d \rightarrow$ $^{4}\hspace{-0.03cm}\mbox{He} \eta$ and $ d d \rightarrow$ ($^4$He$\eta$)$_{bound} \rightarrow X $ cross sections was recently proposed with a broad range of real ($V_{0}$) and imaginary…
The process e+e- to 2 (or 3) gammas is studied using data recorded with the OPAL detector at LEP. The data sample taken at a centre-of-mass energy of 189 GeV corresponds to a total integrated luminosity of 178 pb-1. The measured…
We present a mini-review of present constraints of the large extra dimension scenario. We show many experiments and considerations that can constrain the fundamental scale of the large extra dimension. We observe that constraints come from…
The realization of experimental platforms exhibiting one dimensional (1D) quantum phenomena has been elusive, due to their inherent lack of stability, with a few notable exceptions including spin chains, carbon nanotubes and ultracold…
We explore the possible interpretation of the large-$Q^2$ anomaly reported by the H1 and ZEUS collaborations in terms of stop squark production off a strange quark in the proton via an R-violating interaction. This "strange stop"…
We study the formation and detection at the next linear $e^+e^-$ collider of bound states of level-1 quark Kaluza-Klein excitations ${\cal B}_{KK}$ within a scenario of universal extra-dimensions (UED).
We consider a theory of modified gravity possessing d extra spatial dimensions with a maximally symmetric metric and a scale factor, whose (4+d)-dimensional gravitational action contains terms proportional to quadratic curvature scalars.…
It would be extremely useful to know whether a particular low energy effective theory might have come from a compactification of a higher dimensional space. Here, this problem is approached from the ground up by considering theories with…
The $\eta_c$ meson leptoproduction is calculated within the nonrelativistic QCD framework for the first time. It is found that the colour-singlet channel, although suppressed by a factor of $\alpha_s$ relative to the colour-octet ones,…
We investigate the production of fourth generation neutrino in the context of new $e \nu_4 W$ magnetic dipole moment type interaction in $ep$ collisions at the future lepton-hadron colliders. We have obtained the mass limits of 700 GeV for…
We study the most promising signals of Constrained Minimal Supersymmetry detectable at a luminosity upgraded 2 TeV Fermilab Tevatron collider. Using a full event-level Monte Carlo based on Pythia/Jetset, we simulate the trilepton signal…
New corrections to General Relativity are considered in the context of modified $f(R)$ gravity, that satisfy cosmological and local gravity constraints. The proposed models behave asymptotically as $R-2\Lambda$ at large curvature and show…
Recent theories propose that quantum gravity effects may be observable at LEP energies via gravitons that couple to Standard Model particles and propagate into extra spatial dimensions. The associated production of a graviton and a photon…
We present collider tests of the recent proposal for weak-scale quantum gravity due to new large compact space dimensions in which only the graviton ($\G$) propagates. We show that the existing high precision LEP-I $Z$-pole data can impose…
We suggest a method to simulate lattice compact Quantum Electrodynamics (cQED) using ultracold atoms in optical lattices, which includes dynamical Dirac fermions in 2+1 dimensions. This allows to test dynamical effects of confinement as…
Possible oblique effects from vector particles that are strongly coupled to the known gauge bosons are calculated for the case of final hadronic states produced at future $e^+e^-$ colliders, using a formalism that was recently proposed and…
The QED effective Lagrangian in the presence of an arbitrary constant electromagnetic background field at finite temperature is derived in the imaginary-time formalism to one-loop order. The boundary conditions in imaginary time reduce the…