Measurement of the magnetic moment of the positive muon by a stroboscopic muon-spin-rotation technique

Journal Article · Sun Jan 31 23:00:00 EST 1982 · Phys. Rev. D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.25.652· OSTI ID:5654494

Klempt, E; Schulze, R; Wolf, H; Camani, M; Gygax, F N; Rueegg, W; Schenck, A; Schilling, H

A new determination of the magnetic moment of the positive muon in units of the magnetic moment of the proton is presented. The Larmor precession of positive muons in liquid bromine was observed by a stroboscopic technique in a field of 0.75 T and combined with concomitant proton NMR measurements in the same chemical environment. The stroboscopic method allows use of the full muon stopping rate available at the Schweizerisches Institut fuer Nuklearforschung (SIN) muon channel. Moreover, it permits an intrinsically precise determination of muon Larmor frequency and proton NMR frequency measuring the magnetic field by comparison with the stable reference frequency of the SIN accelerator (..delta cap omega../..cap omega..roughly-equal10/sup -8/). Two different bromine targets were used which allowed an unambiguous determination of the chemical field shift experienced by the muons. One target contained pure and water-free liquid bromine (Br/sub 2/), where stopped muons form (..mu../sup +/e/sup -/)Br molecules. The other target was slightly contaminated with water; there a chemical reaction chain places the muons into (..mu../sup +/e/sup -/)HO molecules. The diamagnetic shielding of protons in the analogous molecules HBr and H/sub 2/O in liquid bromine was measured by high-resolution NMR. Values for the isotopic shift of the diamagnetic shielding, when protons are replaced by muons, are available from quantum chemical calculations. After application of the chemical-shift corrections, the results from the two different bromine targets are consistent. The final result is ..mu../sub ..mu..//..mu../sub p/ = 3.183 344 1(17) (or +- 0.53 ppm). This value agrees with other recent precision determinations of ..mu../sub ..mu..//..mu../sub p/. For the muon mass the present result implies m/sub ..mu..//m/sub e/ = 206.768 35(11) ( +- 0.53 ppm).

• Research Organization: Institut fuer Physik der Universitaet Mainz, D-6500 Mainz, Federal Republic of Germany
• OSTI ID: 5654494
• Journal Information: Phys. Rev. D; (United States), Journal Name: Phys. Rev. D; (United States) Vol. 25:3; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

645101* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Electromagnetic Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANGULAR MOMENTUM
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
BARYONS
BROMINE
DATA
ELECTRODYNAMICS
ELEMENTARY PARTICLES
ELEMENTS
EXPERIMENTAL DATA
FERMIONS
FIELD THEORIES
HADRONS
HALOGENS
INFORMATION
LARMOR PRECESSION
LEPTONS
MAGNETIC MOMENTS
MAGNETIC RESONANCE
MASS
MUONS
MUONS PLUS
NONMETALS
NUCLEAR MAGNETIC RESONANCE
NUCLEONS
NUMERICAL DATA
PARTICLE PROPERTIES
PRECESSION
PROTONS
QUANTUM ELECTRODYNAMICS
QUANTUM FIELD THEORY
RESONANCE
REST MASS
SPECTRAL SHIFT
SPIN