arXiv subjects
Publications and source records attributed to George Jikia.
We present the next-to-leading-order cross sections of the heavy quark-antiquark pair production in polarized photon-photon collision for the general case of photon polarizations. The numerical results for top-antitop production cross sections together with production asymmetries are obtained for linearly polarized photon-photon collisions, including one-loop QCD radiative corrections.
Perturbative QCD one-loop corrections to the cross sections of the $b\bar b$ $(c\bar c)$ quark pair production in polarized photon-photon collisions, as well as cross sections of the radiative processes photon-photon ->$b\bar b g$,$c\bar c g$ leading to two- and three-jet final states are calculated. It is shown that the signal from the intermediate mass Higgs boson is observable and precise measurements of the Higgs boson two-photon width are possible at a photon-photon collider, although the statistical significance is substantially reduced with respect to the tree level calculations. We demonstrate that virtual corrections are of the same order or larger than the Born contribution in the $J_z=0$ channel at high energy for small values of the cutoff $y_{cut}$, separating two-jet from three-jet topologies. The nature of these large corrections is elucidated. For $b\bar b$ pair production at $\sqrt{s_{γγ}}\sim 100$~GeV and for small values of $y_{cut}\leq 0.04$ the higher order resummation of double logarithmic terms ${\cal O}\left(α_s m_b^2/s\ln^2(s/m_b^2)\right)$ is needed.
We study the signals and backgrounds for a heavy Higgs boson in the processes $γγ\to WWWW$, $γγ\to WWZZ$ at the photon linear collider. The results are based on the complete tree level SM calculation for these reactions. We show that the invariant mass spectrum of central $WW$, $ZZ$ pairs is sensitive to the signal from Higgs boson with a mass up to 1~TeV at a 2~TeV linear collider for integrated luminosity of 300~fb$^{-1}$. At 1.5~TeV PLC Higgs boson with a mass up to 700~GeV can be studied. The nonresonant longitudinal gauge boson scattering ($m_H=\infty$) can be detected in photon-photon collisions at $e^+e^-$ center-of-mass energy of 3~TeV.
We present production rates of the two- and three-jet final states for the processes of massive $c\bar c/b\bar b$ quark production in circularly polarized photon-photon collisions, including QCD radiative corrections. Lowest order cross section, one-loop virtual correction and gluon emission correction are shown to be of the same order of magnitude for $b\bar b$ quark production at $\sqrt{s_{γγ}}\sim 100$~GeV. It is shown that the signal from intermediate mass Higgs boson is observable at photon-photon collider, although the statistical significance is substantially reduced with respect to the tree level calculation.
We study the signals for a heavy Higgs boson in the processes $γγ\to WWWW$, $γγ\to WWZZ$ at the photon linear collider. The results are based on the first complete tree level calculation for these reactions. Using a forward ``spectator" $W$ tag, central ``spectator" $W$ veto to suppress backgrounds from transverse $W$, $Z$ production we show that the invariant mass spectrum of central $WW$, $ZZ$ pairs is sensitive to Higgs boson with a mass up to 1~TeV at a 2~TeV linear collider.