Related papers: SUSY signals at HERA in the no-scale flipped SU(5)…
We study the most promising signals for supersymmetry at LEPII in the context of two well motivated supergravity models: (i) the minimal $SU(5)$ supergravity model including the stringent constraints from proton stability and a not too…
A search for stop production in R-parity-violating supersymmetry has been performed in $e^{+}p$ interactions with the ZEUS detector at HERA, using an integrated luminosity of 65 pb$^{-1}$. At HERA, the R-parity-violating coupling $\lambda'$…
A thorough study is performed on pair production and signatures of supersymmetric neutralinos in the MSSM at LEP2. Particular attention is paid to the region of the SuSy parameter space where the associated production of lightest and…
We have searched for the production of a selectron and a squark in $e^+p$ collisions at a center-of-mass energy of 300 GeV using the ZEUS detector at HERA. The selectron and squark are sought in the direct decay into the lightest neutralino…
Working within the framework of the minimal supergravity model with gauge coupling unification and radiative electroweak symmetry breaking (SUGRA), we map out regions of parameter space explorable by experiments at LEP2, for center of mass…
We consider the baryon parity signals at HERA for the case of the MSSM production mechanisms and the decays via the lepton number violating couplings $L_iQ{\bar D}$. We can probe very small Yukawa couplings $\lam' \gsim 3\cdot 10^{-6}$,…
In the framework of the minimal supersymmetric standard model and the $R$-parity breaking model, we investigate various production processes of the supersymmetric partner at HERA energies. Our emphasis is paid upon the scalar top quark, the…
Recent results of searches for new physics at HERA using the complete data sample corresponding to about 0.5/fb per experiment are reviewed. Searches for leptoquarks, isolated leptons (electrons, muons and taus) and a generic search for new…
We examine various aspects of supersymmetric particle production at linear $e^+e^-$ colliders operating at a centre of mass energy of $\sqrt{s}=500$ GeV, and integrated luminosity of $\int {\cal L}dt=20-50$ fb$^{-1}$. Working within the…
The direct pair-production of the $\tilde{\tau}$, is one of the most interesting channels to search for SUSY in: the $\tilde{\tau}$ is likely to be the lightest of the scalar leptons, and the signature of $\tilde{\tau}$ pair production is…
One of the most interesting channels to search for SUSY is the direct pair-production of the $\tau$-lepton superpartner, $\widetilde{\tau}$. The $\widetilde{\tau}$ is with high probability the lightest of the scalar leptons, so one of the…
In R-parity violating supersymmetry a gaugino can be produced at HERA by the t-channel exchange of a selectron between the beam positron or electron and an initial quark from the beam proton. In the generic MSSM model the gaugino can decay…
Weak-scale supersymmetry remains to be one of the best-motivated theories of physics beyond the Standard Model. We evaluate the sensitivities of the High Luminosity (HL) and High Energy (HE) upgrades of the LHC to gluinos and stops,…
The production of photons at very small angles with respect to the proton beam direction is studied in deep-inelastic positron-proton scattering at HERA. The data are taken with the H1 detector in the years 2006 and 2007 and correspond to…
The semi-inclusive reaction e+ p -> e+ X p was studied with the ZEUS detector at HERA using an integrated luminosity of 12.8 pb-1. The final-state proton, which was detected with the ZEUS leading proton spectrometer, carried a large…
The production of $\phi$ mesons in the reaction $e^{+}p \rightarrow e^{+} \phi p$ ($\phi \rightarrow K^{+}K^{-}$) at a median $Q^{2}$ of $10^{-4} \ \rm{GeV^2}$ has been studied with the ZEUS detector at HERA. The differential $\phi$…
The direct pair-production of the superpartner of the $\tau$-lepton, the $\widetilde{\tau}$, is one of the most interesting channels to search for SUSY in: the $\widetilde{\tau}$ is likely to be the lightest of the scalar leptons, and is…
Given that it will take quite some time for the Large Hadron Collider (LHC) to reach its desired luminosity, it is important to investigate the most favorable scenario in which supersymmetry (SUSY) may be discovered at the early runs at the…
We study the feasibility of measuring semi-exclusive photon production \gamma + p \to \gamma + Y at HERA. The cross section of photons produced at large transverse momenta, recoiling off an inclusive system Y of limited mass, can without…
A search for gravitinos produced in ep collisions is performed using the H1 detector at HERA. The data were taken at a centre-of-mass energy of 319 GeV and correspond to an integrated luminosity of 64.3 pb^{-1} for e^+p collisions and 13.5…