# WIT2014 Workshop on Intelligent Trackers

May 14 – 16, 2014
University of Pennsylvania
US/Eastern timezone

## A New Track Reconstruction Algorithm for the Mu3e Experiment based on a fast Multiple Scattering Fit

May 14, 2014, 4:30 PM
30m
25' presentation + 5' for discussion

#### 25' presentation + 5' for discussion

Oral presentation

### Speaker

Dr Alexandr Kozlinskiy (University Heidelberg)

### Description

A new track reconstruction algorithm developed for the high track multiplicity environment of the *Mu3e* experiment, where track uncertainties are dominated by multiple scattering, is presented. The goal of the *Mu3e* experiment is to search for the lepton flavor violating decay $\mu^+ \rightarrow e^+ e^- e^+$. To reach a sensitivity of $10^{-16}$ the experiment will be performed at a future high intensity beam line (*HiMB*) at the Paul-Scherrer Institute (Switzerland) providing more than $10^9$ muons per second. Muons with a momentum of $\approx$ 28 MeV are stopped on a target. Their decay at rest, in which mainly low momentum positrons with energies below 53 MeV are produced, is analyzed by the *Mu3e* tracking detector consisting of four cylindrical layers of thin silicon pixel sensors. The high granularity of the pixel detector with a pixel size of $80 \times 80~\mu\textrm{m}^2$ allows for a precise track reconstruction in the high occupancy environment of the *Mu3e* experiment reaching 100 tracks per readout frame of 50 ns. These tracks will be reconstructed online using a triggerless readout scheme. The implementation of a fast 3-dimensional multiple scattering fit based on hit triplets, where spatial uncertainties are ignored, is described and performance results in the context of *Mu3e* experiment are presented. Also the implementation on Graphics Processor Units (GPUs) for fast online reconstruction is discussed.

### Primary author

Dr Alexandr Kozlinskiy (University Heidelberg)

### Co-authors

Andre Schoening (Physikalisches Institut-Ruprecht-Karls-Universitaet Heidelberg-U) Moritz Kiehn (Ruprecht-Karls-Universitaet Heidelberg) Niklaus Berger (Uni Heidelberg) Mr Sebastian Schenk (University Heidelberg)

 Slides