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playground:serena_g_galilei2021

# Muon detection in electron-positron annihilation for muon collider studies

## Introduction

The LEMMA project 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 $e^{+}$ $e^{-}$ $\rightarrow$ $µ^{+}$ $µ^{-}$ process, impinging on a low $Z$ fixed target could produce muons withnaturally small divergence, resulting in a low transverse emittance.

## Tracker- absorbers correlation

As a first step, this analysis studied the relation betweenthe 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. Fig. 1 shows the average 10 electron (muon) released energy $\left \langle E_{3} \right \rangle$ in the central LG unit in blue (green), as a function of the $x$ position measured by the tracker.

## HOrizontal Smart Absorber efficiency

The efficiency of each HORSA active layer has been studied using a muonbeam 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 inall four layers while $N_{4}$ (j) represents the number of events with signals in time coincidence in all the layers but the j one. The overall efficiency of the HORSAabsorber 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.

Qualche imprecisione (es. $N_4$ non ha il “$\left(j\right)$), la figura andava centrata, ma va bene. Ti do 1h di lavoro a casa.

playground/serena_g_galilei2021.txt · Ultima modifica: 2021/12/13 07:14 da fausto.casaburo