相关论文: Singular Cross Sections in Muon Colliders
If calculated in the standard way, the cross section for the collision of two unstable particles turns out to diverge. This is because this cross section is actually proportional to the size of the colliding beams. The effect is called the…
A possible alternative way of producing muons (or other unstable particles) for colliders is proposed. It consists in colliding beams in a "chasing beam" configuration, i.e. collisions of two beams having the same direction but with…
The top-quark, $W$ and $Z^0$ bosons have widths that are a sizable fraction of their masses and will be produced copiously at upcoming accelerators. Yet S-matrix theory cannot treat unstable particles as external states. Dealing with…
One of the useful features of muon colliders is the naturally narrow spread in beam energies. Measurements of threshold cross sections then become a prime candidate for precision measurements of particle masses, widths, and couplings as…
I consider the process $\mu^+\mu^-\to e\bar{\nu}W^+$ in the case when the effective mass of the $(e\bar\nu)$ system than the muon mass. In this case the momentum transferred from the initial muon to the $e\bar\nu$ system (the virtual…
Muon colliders are expected to naturally have a small spread in beam energy making them an ideal place to study the excitation curve. We present the parameter determinations that are possible from measuring the total cross section near…
The beam energy spread is a major issue in future attempts to study the $t\overline{t}$ threshold at $e^+e^-$ colliders. Muon colliders are expected to naturally have narrow band beams making them an ideal place to study the excitation…
It is known that some high-energy processes have a $t$-channel singularity in the physical region. In this paper we show that this singularity is regularized if one takes into account the finite sizes of the colliding beams, i.e. the…
The measurements of kinematical endpoints, in cascade decays of supersymmetric particles, in principle allow for a determination of the masses of the unstable particles. However, in this procedure ambiguities often arise. We here illustrate…
Accurate measurements of particles masses, couplings and widths are possible by measuring production cross sections near threshold. We discuss the prospects for performing such measurements at a high luminosity muon collider.
We explore physics of unstable particles when mother particle mass is around the sum of its daughter particle masses. In this case, the conventional wave function renormalization factor is ill-defined. We propose a simple resolution of the…
Among the post-LHC generation of particle accelerators, the muon collider represents a unique machine with capability to provide very high energy leptonic collisions and to open the path to a vast and mostly unexplored physics programme.…
Two methodological troubles of the quantum theory of collisions are considered. The first is the undesirable interference of the incident and scattered waves in the stationary approach to scattering. The second concerns the nonstationary…
We consider pair production and decay of fundamental unstable particles in the framework of a modified perturbation theory (MPT), which treats resonant contributions of unstable particles in the sense of distributions. The cross-section of…
The problem of the origin of the mu parameter in the Minimal Supersymmetric Standard Model can be solved by introducing singlet supermultiplets with non-renormalizable couplings to the ordinary Higgs supermultiplets. The Peccei-Quinn…
If scale invariance is exact, unparticles are unlikely to be probed in colliders since there are stringent constraints from astrophysics and cosmology. However these constraints are inapplicable if scale invariance is broken at a scale mu…
The influence of the scalar unparticle and anomalous couplings at muon colliders in final states with multiple photons in the Randall-Sundrum model is evaluated in detail. The results indicate that with fixed collision energies, the total…
Muon colliders provide an exciting new direction to expand the energy frontier of particle physics. We point out a new use of these facilities for neutrino and beyond the Standard Model physics using their main detectors. Muon decays along…
While information exists on high energy negative particle channeling there has been little study of the challenges of negative particle bending and channeling collimation. Partly this is because negative dechanneling lengths are relatively…
The cross section for the reactions of the type $\mu^-\mu^+ \to e\bar\nu_e X$ can not be calculated by the standard methods due to the $t$--channel singularity in the physical region. In this letter we show that accounting for the finite…