Phase Space Density Evolution in MICE

TL;DR

This paper discusses the use of phase space density evolution measurements in MICE to demonstrate ionization cooling of muon beams, employing robust statistical methods to quantify cooling effects.

Contribution

It introduces reliable, non-parametric techniques for estimating phase space density, enabling quantitative assessment of muon beam cooling in MICE.

Findings

Phase space density can be reliably estimated using non-parametric methods.

Contraction of phase space volume indicates successful muon beam cooling.

Robust techniques are suitable despite transmission losses and non-linearities.

Abstract

The Muon Ionization Cooling Experiment (MICE) will demonstrate the feasibility of ionization cooling, the technique by which it is proposed to cool the muon beam at a future neutrino factory or muon collider. The position and momentum reconstruction of individual muons in the MICE trackers allows for the development of alternative figures of merit in addition to beam emittance. Contraction of the phase space volume occupied by a fraction of the sample, or equivalently the increase in phase space density at its core, is an unequivocal cooling signature. Single-particle amplitude and non-parametric statistics provide reliable methods to estimate the phase space density function. These techniques are robust to transmission losses and non-linearities, making them optimally suited to perform a quantitative cooling measurement in MICE.