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playground:aurora_p_pietrobono2021

Muon detection in electron-positron annihilation for muon collider studies

Introduction

The LEMMA project [4] aims to study the possibility of producing muons from the $e^{+}e^{-}$ annihilation process. A high intensity positron beam, with energy just above the 43.7 GeV threshold for muon pair production through the $e^{+}e^{-}\rightarrow\mu^{+}\mu^{-}$ process, impinging on a low Z fixed target [5] could produce muons with naturally small divergence, resulting in a low transverse emittance.

Tracker- absorbers correlation

As mentioned before, the experimental apparatus is arranged so that the magnet deflects particles with energy $ E_{0} $ towards the central unit of the LG (block 3 in Fig. 2). As a first step, this analysis studied the relation between the particle’s $x$ position measured by the tracker positioned before the first scintillator of the negative arm and the energy released $ E_{3}$ in the central LG unit (subscript number refers to Fig. 2). Fig. 1 shows the average 10 electron (muon) released energy ( $ E_{3}$ ) in the central LG unit in blue (green), as a function of the $x$ position measured by the tracker.

Figure 1: Average energy released $\left\langle E_{3}\right\rangle$ by 22 GeV electrons (blue, on the top) and muons (green, on the bottom) in the central LG unit as a function of the local x position measured by the tracker. Vertical solid lines are used to mark the region 6 cm $< x <$ 9 cm, considered for further analysis

HOrizontal Smart Absorber efficiency

The efficiency of each HORSA active layer has been studied using a muon beam with energy $ E_{0}$. The efficiency of each HORSA active layer $ j = 5, 6, 7, 8$ is defined as:$$\varepsilon_{j}=\frac{N_{4}}{N_{3}\left(j\right)}$$ where $N_{4}$ represents the number of events with signals in time coincidence in all four layers while $N_{3} (j)$ represents the number of events with signals in time coincidence in all the layers but the $j$ one. The overall efficiency of the HORSA absorber is defined as $$\varepsilon_{\text{HORSA}}=\prod_{j=5}^{8}\varepsilon_{j}$$ Results obtained from the run with a muon beam of energy $ E_{0}$ and no target in place are given in Tab. 1, together with the corresponding statistical uncertainties evaluated assuming binomial statistics.

$j$ $\varepsilon_{j}\left(\%\right)$ $\varepsilon_{HORSA}\left(\%\right)$
5$ 97.04\pm0.56$$84.2\pm1.4$
6$ 95.50\pm0.66$
7$ 93.26\pm0.98$
8$ 97.44\pm0.79$

Table 1: Efficiencies to detect a 22 GeV muon in each of the fused silica HORSA layers together with the overall HORSA efficiency

Nota

Questa è una pagina di prova di utilizzo di Wiki Lab2Go. Il testo, la figura e la tabella riportati sono stati presi dall'articolo scientifico arxiv:2105.12624

Commento di Fausto C.

La figura andava centrata, inoltre qualche imprecisione ma va bene. Ti do 1h di lavoro a casa

playground/aurora_p_pietrobono2021.txt · Ultima modifica: 2021/12/09 07:27 da fausto.casaburo