Related papers: Anomalous gamma gamma interaction
We have searched for exclusive 2-photon production in proton-antiproton collisions at sqrt{s} = 1.96 TeV, using 532/pb of integrated luminosity taken by the Run II Collider Detector at Fermilab. The event signature requires two…
We propose a new kind of two-particle correlation of identified hadrons in longitudinal rapidity space, called $G_{\alpha\beta}(y_{\alpha},y_{\beta})$, which can reflect clearly the charge correlations of hot quark system produced in AA…
We investigate the anomalous interactions of heavy up-type quark t' in a $\gamma \gamma$ collision at the LHC. We have obtained 95% confidence level(CL)limit of $t'q \gamma$ anomalous coupling by taking into account three forward detector…
Due to coherence, there are strong electromagnetic fields of short duration in very peripheral collisions. They give rise to photon-photon and photon-nucleus collisions with a high flux up to an invariant mass region hitherto unexplored…
The reaction e+ e- -> e+ e- gamma* gamma* -> e+ e- hadrons is analysed for quasi-real virtual photons using data collected by the L3 detector during the LEP high energy runs at sqrt(s) = 183 and 189 GeV. Preliminary results on the cross…
Double-tag events in two-photon collisions are studied using the L3 detector at LEP centre-of-mass energies from root(s)=189 GeV to 209 GeV. The cross sections of the e+e- -> e+e- hadrons and gamma*gamma* -> hadrons processes are measured…
The next-to-next-to-leading order (NNLO) QCD corrections to top quark threshold pair production in gamma-gamma collisions are computed. The NNLO effects turn out to be significant. Threshold cross sections in gamma-gamma and e+e- collisions…
The process e^+e^- -> gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 25.38 pb^{-1} taken at centre-of-mass energies of 130-172 GeV. The…
We review the methods and results obtained in an analysis of the experimental heavy ion collision research program at nuclear beam energy of 160-200A GeV. We study strange, and more generally, hadronic particle production experimental data.…
We analyze the potential of the CERN Large Hadron Collider (LHC) to study anomalous quartic vector-boson interactions Z Z gamma gamma, Z Z Z gamma, W+ W- gamma gamma, and W+ W- Z gamma through the weak boson fusion processes q q -> q q…
As the heaviest known fundamental particle, the top quark ensures testing of the Standard Model and occupies a significant role in a lot of theories of new physics beyond the Standard Model. Up to now, the top quark has been only generated…
A search for single top quark production is performed in e^\pm p collisions at HERA. The search exploits data corresponding to an integrated luminosity of 118.3 pb^-1. A model for the anomalous production of top quarks in a flavour changing…
The cross section of the process e^+ e^- -> Z \gamma\gamma -> qq \gamma \gamma is measured with 215 pb^-1 of data collected with the L3 detector during the final LEP run at centre-of-mass energies around 205 GeV and 207 GeV. No deviation…
The production of $\nu \bar{\nu} \gamma \gamma$ in high-energy $e^+e^-$ collisions offers a window on anomalous quartic gauge boson couplings. We investigate the effect of two possible anomalous couplings on the cross section for $\nu…
New results from the experiments ALEPH, DELPHI, L3, and OPAL on heavy quark production in gammagamma collisions are presented. Inclusive charm and bottom production are investigated at LEP~2 energies. The total and differential cross…
The process e+e- to gamma gamma (gamma) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 56.2 pb-1 taken at a centre-of-mass energy of 183 GeV. The measured…
The reactions gamma-gamma to eta_c eta_c and gamma gamma to eta_c + X are discussed within the three gluon exchange model. We give predictions for the differential cross-sections and discuss feasibility of measuring these processes at LEP2…
A high-energy lepton-lepton collider will give us a unique possibility to study e-gamma and gamma-gamma interactions at high energies. The high-energy photons can be generated by Compton back-scattering of laser light on the high-energy…
Recently, the ALICE Collaboration reported an enhancement of the yield ratio of strange and multi-strange hadrons to charged pions as a function of multiplicity at mid-rapidity in proton-proton, proton-lead, lead-lead, and xenon-xenon…
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…