DECAY ASYMMETRY OF COSMIC RAY MUONS

Journal Article · Fri Jun 01 04:00:00 EDT 1962 · Proc. Phys. Soc. (London)

DOI:https://doi.org/10.1088/0370-1328/79/6/312· OSTI ID:4824624

Sen Gupta, S N; Sinha, M S

Ivestigations of the decay asymmetry of cosmic muons were carried out in two energy bands, using a multiplate cloud chamber. Advantages of the cloud chamber are: the decay electrons are detected from zero delay up to about 50 ms, which is never possible in the delayed coincidence method; the change of direction of the decay electrons in the absorbing material due to scattering is avoided by dividing the whole absorber into thin plates separated by gaps in which the electrons are observed. Even if these electrons are subsequently scattered, their original direction of emission is clearly observed. After careful scanning of about 36,000 photographs taken using a fourfold coincidence and anticoincidence system, about 1500 unambiguous mu -e decay events were selected. Of these, 102l events correspond to a muon momentum interval fo 0.30 to 0.40 Bev/c and 482 events to an interval of 1.3 to 1.4 Bev/c at the experimental station, at 2.2 km. The up-dowm ratios of electrons emitted are 1.17 plus or minus 0.05 and 1.18 plus or minus 0.08, respectively, which yield partial longitudinal polarizations of 0.34 plus or minus 0.09 and 0.36 plus or minus 0.11 after correcting for the depolarization effect of the atmosphere and moderator. No evidence was found for the increase in the degree of polarization with increase of momentum of the muons. The absolute magnitude of the polarization is consistent with a K/ pi ratio of about 5% in the pion spectral region at 0.2 to 5.6 Bev. (auth)

• Research Organization: Bose Inst., Calcutta
• NSA Number: NSA-16-022842
• OSTI ID: 4824624
• Journal Information: Proc. Phys. Soc. (London), Journal Name: Proc. Phys. Soc. (London) Vol. Vol: 79
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ABSORPTION
ATMOSPHERE
CLOUD CHAMBERS
COINCIDENCE METHODS
COSMIC RADIATION
COUNTERS
DECAY
DEPOLARIZATION
ELECTRONS
ENERGY RANGE
KAONS
MEASURED VALUES
MEV RANGE
MOMENTUM
MUONS
PARTICLE TRACKS
PHYSICS
PIONS
PLATES
POLARIZATION
SCATTERING
THICKNESS