Search for mixing of muonium and antimuonium

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5847419

Huber, T M

The mixing of muonium ({mu}{sup {plus}} e{sup {minus}} ) and the antimuonium ({mu}{sup {minus}} e{sup {plus}}) is prohibited by the additive lepton number conservation law incorporated in the standard model. However, in many extensions to the standard model, reactions which do not conserve lepton number are allowed. The predictions of the muonium-antimuonium coupling strength within several models are discussed. In this experiment, thermal muonium was created by stopping muons in a SiO{sub 2} powder target. As a signature for antimuonium, a {mu}{sup {minus}} from antimuonium would create {sup 184}Ta in an adjacent tungsten foil. After a twelve hour exposure to muonium, the tungsten sample was removed and the characteristic decay of {sup 184}Ta was detected by a shielded Ge spectrometer apparatus in a separate location. The background rate for the {sup 184}Ta decay signature is less than one event per month, allowing a high-sensitivity, low-background search for mixing of muonium and antimuonium. No events were observed which satisfied the criteria for {sup 184}Ta. The resulting upper limit, at 90% confidence, on the probability that a muonium atom spontaneously converts to antimuonium is 2.0 {times} 10{sup {minus}6}. This corresponds to a limit of G {lt} 0.28 G{sub F} on the effective four-fermion coupling constant between muonium and antimuonium.

• Research Organization: Wyoming Univ., Laramie, WY (USA)
• OSTI ID: 5847419
• Country of Publication: United States
• Language: English

Related Subjects

640303* -- Atomic
Molecular & Chemical Physics-- Positronium
Muonium
& Muonic & Mesic Atoms & Molecules
74 ATOMIC AND MOLECULAR PHYSICS
ANTIMATTER
ANTIPARTICLES
ATOMS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CONSERVATION LAWS
COUPLING CONSTANTS
DATA
DECAY
ELEMENTARY PARTICLES
EXPERIMENTAL DATA
FERMIONS
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
INFORMATION
ISOTOPES
LEPTON NUMBER
LEPTONS
LIMITING VALUES
MATHEMATICAL MODELS
MUONIC ATOMS
MUONIUM
MUONS
NUCLEAR DECAY
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
PARTICLE MODELS
RADIOISOTOPES
STANDARD MODEL
TANTALUM 184
TANTALUM ISOTOPES
UNIFIED GAUGE MODELS