arXiv subjects
Publications and source records attributed to S. F. Novaes.
We study the production of composite scalar leptoquarks in $eγ$ colliders, and we show that an $e^+e^-$ machine operating in its $eγ$ mode is the best way to look for these particles in $e^+e^-$ collisions, due to the hadronic content of the photon.
We analyze the production and detection of the Higgs boson in the next generation of linear $e^+e^-$ colliders operating in the $eγ$ mode. In particular, we study the production mechanism $e + γ\rightarrow e γγ\rightarrow e + H$, where one photon is generated via the laser backscattering mechanism, while the other is radiated via the usual bremsstrahlung process. We show that this is the most important mechanism for Higgs boson production in a $500$ GeV $eγ$ collider for $M_H\raisebox{-.4ex}{\rlap{$\sim$}} \raisebox{.4ex}{$>$}140$ GeV. We also study the signals and backgrounds for detection of the Higgs in the different decay channels, $b \bar b$, $W^+W^-$, and $ZZ$, and suggest kinematical cuts to improve the signature of an intermediate mass Higgs boson.
A possible way of producing gravitons in the laboratory is investigated. We evaluate the cross section electron + photon $\rightarrow$ electron + graviton in the framework of linearized gravitation, and analyse this reaction considering the photon coming either from a laser beam or from a Compton back-scattering process.
The exchange of gluons between heavy quarks produced in $e^+e^-$ interactions results in an enhancement of their production near threshold. We study QCD threshold effects in $γγ$ collisions. The results are relevant to heavy quark production by beamstrahlung and laser back-scattering in future linear collider experiments. Detailed predictions for top, bottom and charm production are presented.