arXiv subjects

H. Nadeau

Publications and source records attributed to H. Nadeau.

5 recordsLinked to original sources

arXiv1998

Bilepton Production at Hadron Colliders

We examine, as model-independently as possible, the production of bileptons at hadron colliders. When a particular model is necessary or useful, we choose the 3-3-1 model. We consider a variety of processes: q anti-q -> Y^{++} Y^{--}, u anti-d -> Y^{++} Y^{-}, anti-u d -> Y^+ Y^{--}, q anti-q -> Y^{++} e^{-} e^{-}, q anti-q -> phi^{++} phi^{--}, u anti-d -> -> phi^{++} phi^{-}, and anti-u d -> phi^{+} phi^{--}, where Y and phi are vector and scalar bileptons, respectively. Given the present low-energy constraints, we find that at the Tevatron, vector bileptons are unobservable, while light scalar bileptons (M_phi <= 300 GeV) are just barely observable. At the LHC, the reach is extended considerably: vector bileptons of mass M_Y <= 1 TeV are observable, as are scalar bileptons of mass M_phi <= 850 GeV.

hep-ph↗

arXiv1995

Inverse Neutrinoless Double Beta Decay Revisited

We critically reexamine the prospects for the observation of the $ΔL=2$ lepton-number-violating process $\eeWW$ using the $e^-e^-$ option of a high-energy $e^+e^-$ collider (NLC). We find that, except in the most contrived scenarios, constraints from neutrinoless double beta decay render the process unobservable at an NLC of $\sqrt{s}<2$ TeV. Other $ΔL=2$ processes such as $\ggllww$, $\egnllw$, $\eennll$ ($\ell=μ,τ$), and $\egeww$, which use various options of the NLC, require a $\sqrt{s}$ of at least 4 TeV for observability.

hep-ph↗

arXiv1994

Single Dilepton Production at $e^+e^-$, $eγ$ and $γγ$ Colliders

We calculate the cross sections for the single production of doubly-charged dileptons, both scalar and vector, at $e^+e^-$, $eγ$ and $γγ$ colliders at $\sqrt{s}=500$ GeV and 1 TeV. The $eγ$ mode is by far the most promising -- dileptons whose coupling is as weak as $O(10^{-4})α_{em}$ can be observed, for masses virtually up to the kinematic limit. Dileptons of mass up to $\sqrt{s}$ can also be seen in $e^+e^-$ and $γγ$ colliders, for couplings of order $α_{em}$. In all three colliders, most of the cross section comes from events in which the only particles detected are $e^-e^-$, the decay products of the dilepton, yielding an unmistakeable experimental signature.

hep-ph↗

arXiv1993

Single Leptoquark Production

The single production of leptoquarks in $e^+e^-$, $eγ$ and $γγ$ linear colliders is discussed. We show that these new particles could be seen in such machines even if their mass is close to the kinematic limit. (Invited talk given by G.B. at the ``Workshop on Physics and Experiments at Linear $e^+e^-$ Colliders'', Waikoloa, Hawaii, April 26-30, 1993.)

hep-ph↗

arXiv1993

Single Leptoquark Production at $e^+e^-$ and $γγ$ Colliders

We consider single production of leptoquarks (LQ's) at $e^+e^-$ and $γγ$ colliders, for two values of the centre-of-mass energy, $\sqrt{s}=500$ GeV and 1 TeV. We find that LQ's which couple within the first generation are observable for LQ masses almost up to the kinematic limit, both at $e^+e^-$ and $γγ$ colliders, for the LQ coupling strength equal to $α_{em}$. The cross sections for single production of $2^{nd}$- and $3^{rd}$-generation LQ's at $e^+e^-$ colliders are too small to be observable. In $γγ$ collisions, on the other hand, $2^{nd}$-generation LQ's with masses much larger than $\sqrt{s}/2$ can be detected. However, $3^{rd}$-generation LQ's can be seen at $γγ$ colliders only for masses at most $\sim\sqrt{s}/2$, making their observation more probable via the pair production mechanism.

hep-ph↗