Measuring Mean Lifetime of Muon

Course Project: PHY 500: Graduate Physics Lab

Term: Fall 2016

Supervisor: Dr. Muhammad Sabieh Anwar

Institution: Department of Physics, Lahore University of Management Sciences


In this experiment, the mean lifetime of cosmic ray muons in their rest-frame is measured. Muons are stopped in a large block of the scintillator, where they subsequently decay into an electron/positron and two neutrinos. A short light pulse is produced by the stopping muon which is detected and amplified by a photomultiplier tube. When the muon decays a second pulse is produced by the emitted electron or positron. The signals from the photomultiplier are fed into an electronic circuit which determines the time delay between the two pulses. The circuit is connected to a PC which is used to read out the data. The experiment involves the set-up of the equipment, performing the actual measurement, and the subsequent data analysis.


The purpose of this experiment is to understand how photomultiplier tubes and scintillators combined work as a particle detector, study the formation of muons from primary cosmic rays in the atmosphere, analyze the working of high-speed electronic modules so that they can be used to obtain the time difference to calculate the lifetime, understand the workings of the multi-channel analyzer and realize how it is a crucial part of counting different voltage pulses in this experiment, and analyze how curve-fitting parameters influence the final answer.

Schematic diagram of the Muon lifetime experiment.

Project Report:

Complete project report can be downloaded from here (direct link) or from here (researchgate). 



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