相关论文: Muon Colliders, Monte Carlo and Gauge Invariance
We address the problem that the cross section for the collisions of unstable particles diverges, if calculated by standard methods. This problem is considered for beams much smaller than the decay length of the unstable particle, much…
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…
We study $\mu^+\mu^-$ collision with production of some state $F$ (for example, $F= W^+$) and $(e\bar\nu)$ system with the effective mass, which is less than muon mass. In this case the momentum $k$, transferred from $\mu$ to $e\bar\nu$…
For several processes at colliding beams, macroscopically large impact parameters give an essential contribution to the standard cross section. These impact parameters may be much larger than the transverse sizes of the colliding bunches.…
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…
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…
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…
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…
We investigate possible effects of unparticles at the MUonE experiment by considering a general model for unparticle with broken scale invariance, characterized by the scaling dimension $d$ and the energy scale $\mu$ at which the scale…
In particle-based algorithms, the effect of binary collisions is commonly described in a statistical way, using Monte Carlo techniques. It is shown that, in the relativistic regime, stringent constraints should be considered on the sampling…
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…
It is shown how to construct exactly gauge-invariant S-matrix elements for processes involving unstable gauge particles such as the $Z^0$ boson. The results are applied to derive a physically meaningful expression for the cross-section…
The effect of the beam-beam interactions on the stability of impedance mode is discussed. The detuning is evaluated by the means of single particle tracking in arbitrarily complex collision configurations, including lattice non-linearities,…
When computing the properties of reactions involving unstable charged particles care has to be taken to use a gauge invariant amplitude. In this talk we present methods to (automatically) obtain such an amplitude, both at the tree level and…
We present qualitative but precise description of the linear beam-size effect predicted for the processes in which unstable but long--living particles collide with each other. We derive physically pronounced equation for the events rate…
The muon intensity attenuation method to detect heterogeneities in large matter volumes is analyzed. Approximate analytical expressions to estimate the collection time and the signal to noise ratio, are proposed and validated by Monte Carlo…
As it follows from the interrelation of Gamma and Poisson distributions the observed value of asymmetry for Poisson flows of events has the bias. The Monte Carlo experiment confirms the presence of this bias between the observed and initial…
The "proton size puzzle" and the "muon anomalous moment problem" are incomplete descriptions of significant discrepancies of Standard Model calculations with experiments. What is particularly new is that the experiments and theory confront…
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…
The instability of a monoenergetic electron beam in a collisional one-dimensional plasma bounded between grounded walls is considered both analytically and numerically. Collisions between electrons and neutrals are accounted for the plasma…