Measurement of Lifetime of Cosmic Ray Muons
Faculty Mentor Name
Darrel Smith
Format Preference
Oral Presentation
Abstract
In this experiment cosmic rays create scintillation light as they pass through a 5-gallon mineral oil/scintillator detector. Some of the low-energy cosmic muons come to rest in the detector and their subsequent decays (μ+→e+ νμ ν ̅e) are observed as a second burst of light. The decay lifetime of 10,392 stopping muons were measured and the mean muon lifetime τ_μ was calculated. The composition of cosmic muons includes both positive and negative muons; however, a small fraction of the μ cosmic rays are captured by hydrogen atoms in the mineral oil (CH2) thus affecting the accepted lifetime of muon decays (2.197 μS). The muon lifetime measured in this experiment, τµ=(2.092 ±0.019)μS, does not differentiate between positive or negative muons and is consistent with the occurrence of μ ̅ capture on hydrogen.
Location
AC1-114
Start Date
4-10-2015 11:45 AM
End Date
4-10-2015 12:00 PM
Measurement of Lifetime of Cosmic Ray Muons
AC1-114
In this experiment cosmic rays create scintillation light as they pass through a 5-gallon mineral oil/scintillator detector. Some of the low-energy cosmic muons come to rest in the detector and their subsequent decays (μ+→e+ νμ ν ̅e) are observed as a second burst of light. The decay lifetime of 10,392 stopping muons were measured and the mean muon lifetime τ_μ was calculated. The composition of cosmic muons includes both positive and negative muons; however, a small fraction of the μ cosmic rays are captured by hydrogen atoms in the mineral oil (CH2) thus affecting the accepted lifetime of muon decays (2.197 μS). The muon lifetime measured in this experiment, τµ=(2.092 ±0.019)μS, does not differentiate between positive or negative muons and is consistent with the occurrence of μ ̅ capture on hydrogen.