Related papers: Single Leptoquark Production
Possible existence of extra SM families and/or isosinglet E_6 quarks may sufficiently decrease |V_tb| of CKM matrix so that toponia can be formed. Production of pseudoscalar toponium at the LHC and VLHC has been considered. The…
Talk presented at 2nd International Workshop on Physics and Experiments with Linear $e^+e^-$ Colliders (Hawaii, April 1993).
Measurements of top quark production at $e^+e^-$ colliders can provide a leap in precision in our knowledge of top quark properties and open a new window on physics beyond the Standard Model. In this contribution the top quark physics…
The little Higgs models typically contain a new vector-like top quark $T$, which plays a key role in breaking the electroweak symmetry. In the context of the littlest Higgs (LH) model, we study single production of this kind of new particle…
We analyze the production in $e^+e^-$ collisions of new heavy fermions stemming from extensions of the Standard Model. We write down the most general expression for the production of two heavy fermions and their subsequent decays, allowing…
We examine the prospects for studying the diffractive production of high pt photons in the process gamma+gamma -> gamma+X at a future linear collider operating in both ee and gamma-gamma modes. The high luminosity associated with a linear…
We perform a global analysis of the sensitivity of LEP2 and e^+e^- colliders with a c.m. energy in the range 500 - 2000 GeV to new flavor-changing single top quark production in the effective Lagrangian approach. The processes considered…
The process e+e- -> gamma gamma (gamma) is studied using data collected by the OPAL detector at LEP between the years 1997 and 2000. The data set corresponds to an integrated luminosity of 672.3pb-1 at centre-of-mass energies lying between…
The search reaches for both scalar($S$) and vector($V$) leptoquarks at future hadron colliders are summarized. In particular we evaluate the production cross sections of both leptoquark types at TeV33 and LHC as well as the proposed 60 and…
We study the single chargino production $e^+ e^- \to \tilde \chi^{\pm} \mu^{\mp}$ at linear colliders which occurs through the $\l_{121}$ R-parity violating coupling constant. We focus on the final state containing 4 leptons and some…
A search for a first generation scalar leptoquark (LQ) has been performed using the data collected by the OPAL detector in 1996 at e+e- centre-of-mass energies sqrt{s} of 161 and 172 GeV. It is assumed that a single leptoquark can be…
We explore leptoquark production and decay for the $\tilde{R}_{2}$ class of models at the proposed $e^{-} p$ collider LHeC, planned to operate with 150 GeV electron and 7 TeV proton beams. In addition to the coupling of leptoquark with the…
Many extensions of the Standard Model include extra fermions. We here consider a model containing Dirac neutral heavy leptons in addition to massless neutrinos. These neutral heavy leptons can be produced singly along with a massless…
We review the physics involved in the production and decay of top quarks in e^+e^- -> ttbar near threshold, with special emphasis on the recent theoretical study on the decay process of top quarks in the threshold region. The energy-angular…
The dilepton production in diffractive and exclusive processes at forward rapidities considering ultraperipheral $PbPb$ collisions at the LHC is investigated. Predictions for the $e^+ e^-$, $\mu^+ \mu^-$ and $\tau^+ \tau^-$ cross sections…
A high energy linear e^+e^- collider (LC) can also be used as a Photon Collider (PC), using Compton scattering of laser photons on the e^+/e^- beams. The leading order cross-section for the production of heavy quarks, e^+e^- -> e^+e^-…
The diquark exotics which couple to a pair of quarks are predicted by the Compositeness and Superstring inspired E_{6} model. We study the single production of scalar diquarks at LHeC based gamma p collider options. The background for three…
In the frameworks of the littlest Higgs($LH$) model and its extension with T-parity($LHT$), we studied the associated $t\bar th^0$ production process $e^+ e^- \to \gamma\gamma \to t \bar t h^0$ at the future $e^+e^-$ linear colliders up to…
Numerous phenomenological studies and collider searches have probed for the existence of new physics by looking for signatures of leptoquarks (LQs) or vectorlike leptons (VLLs). We consider a new possibility that can arise in theories with…
There exists a world--wide consensus for a future $e^+e^-$ Linear Collider in the energy range between $\sqrt{s}=500--1000$ GeV as the next large facility in HEP. The Linear Collider has a large physics potential for the discovery of new…