Detector Performance Studies at a Muon Collider

Abstract

A Muon Collider represents a possible option for the next generation of high-energy machines. Among the technological challenges in the realization of such a machine, the mitigation of the beam-induced background is one of the most critical issues for the experiments. At the desired instantaneous luminosity, the decay rate of the circulating muons is very high, the decay products and subsequent particles from their interactions with the machine elements can reach the detector and compromise its performance. In this contribution, the results of a first preliminary study is presented of the beam-induced background effects on the detector response in the case of muon beams collisions at a center of mass energy of 1.5 TeV and some background mitigation strategies are illustrated.

Prospects of a future multi-TeV muon collider

“…First, a low-energy acceleration stage brings the energy of the muon beams to ∼100 GeV, subsequently the beams are accelerated to the nominal multi-TeV collision energy and, finally, injected into a collider ring, which will be designed as small as possible to increase the collision frequency and optimized to maximize the delivered luminosity. At every stage of the beam life-cycle, the heat load caused by the electrons from muon decays strains all the machine elements, which require to be properly shielded: a 750-GeV beam with 2×10 12 muons is expected to radiate on average 0.5 kW/m. A promising alternative method has been proposed that exploits a 45-GeV positron beam on a target to produce µ + µ − pairs via electron-positron annihilation.…”

“…The assumed detector model consists of a full-silicon vertex detector and central tracker, a tungsten-silicon sampling electromagnetic calorimeter and a steel-plastic scintillator sampling hadronic calorimeter, all immersed in a solenoidal magnetic field and surrounded by muon chambers. A well-designed detector and the exploitation of state-of-the-art detector technologies and novel reconstruction and analysis techniques can effectively mitigate the BIB effects [12]: the main features of a muon collider detector will be internal shielding, high granularity, and high-precision timing.…”

Luminosity measurement at muon collider

“…The √ = 1.5 TeV BIB effects on the muon detector have been evaluated by looking at its distribution on the muon system. The schematic view of the longitudinal section with respect to the beam axis of the detector [9] [10] used for the full simulation is shown in figure 1 right . In cyan are represented the tungsten nozzles, optimized for √ = 1.5 TeV.…”

Higgs boson couplings at muon collider

“…Despite of the presence of the tungsten cones, ∼ 10 10 BIB particles reach the detector, mainly low energy photons and + / − , neutrons and hadrons. In order to study the BIB effects on the detector components, detailed simulation of the muon collider detector, described in [7], is required. The amount of BIB particles reaching the detector can be reduced by using sensors exploiting information on the energy released by the particles, position and time of arrival at the sub-detectors.…”

“…For example, since BIB particles are partially asynchronous with respect to the bunch-crossing time, a cut on the arrival time of the particles at the detector can reject part of them. Detailed studies on the application of a time cut to the vertex and the tracker systems and its effects on the tracking performances can be found in [7]. The main issue in track reconstruction with BIB is the large number of hits…”