Abstract Title

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

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Apr 10th, 11:45 AM Apr 10th, 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.