Measurement of the parity nonconserving neutral weak interaction in atomic thallium

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1980

OSTI ID:6090167

Bucksbaum, P H

A frequency doubled, flashlamp pumped tunable dye laser is used to excite the 6P/sub 1/2/(F = 0) ..-->.. 7P/sub 1/2/(F = 1) transition at 292.7 nm, with circularly polarized light. An electrostatic field E of 100 to 300 V/cm causes this transition to occur via Stark induced electric dipole. Two field free transitions may also occur: a highly forbidden magnetic dipole M, and a parity nonconserving electric dipole E/sub P/. The latter is presumed to be due to the presence of a weak neutral current interaction between the 6p valence electron and the nucleus, as predicted by gauge theories which unite the electromagnetic and weak interactions. Both M and E/sub p/ interfere with Stark amplitude ..beta..E to produce a polarization of the 7P/sub 1/2/ state. We measure this with a circularly polarized infrared laser beam probe, tuned to the 7P/sub 1/2/ ..-->.. 8S/sub 1/2/ transition. This selectively excites m/sub F/ = +1 or -1 components of the 7P/sub 1/2 state, and we see the polarization as an asymmetry in 8S ..-->.. 6P/sub 3/2/ fluorescence when the probe helicity is reversed. The polarization due to M is ..delta../sub M/ = -2M/(..beta..E). We use it to calibrate the analyzing efficiency. The polarization due to E/sub P/ is ..delta../sub p/ = 2i E/sub P//(..beta..E), and can be distinguished from ..delta../sub M/ by its properties under reversal of the 292.7 nm photon helicity and reversal of the laser direction. A preliminary measurement yielded a parity violation in agreement with the gauge theory of Weinberg and Salam (Conti et al., 1979).

• Research Organization: California Univ., Berkeley (USA)
• OSTI ID: 6090167
• Country of Publication: United States
• Language: English

Related Subjects

640302 -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
640304 -- Atomic
Molecular & Chemical Physics-- Collision Phenomena
645102* -- High Energy Physics-- Particle Interactions & Properties-Experimental-- Weak Interactions & Properties
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
74 ATOMIC AND MOLECULAR PHYSICS
ALGEBRAIC CURRENTS
ATOM COLLISIONS
BEAMS
COLLISIONS
CURRENTS
DATA
DYE LASERS
ELEMENTS
ENERGY-LEVEL TRANSITIONS
EXCITATION
EXPERIMENTAL DATA
INFORMATION
INVARIANCE PRINCIPLES
LASERS
LIQUID LASERS
MATHEMATICAL MODELS
METALS
MULTIPOLE TRANSITIONS
NEUTRAL CURRENTS
NUMERICAL DATA
P INVARIANCE
PARTICLE MODELS
PHOTON COLLISIONS
PHOTON-ATOM COLLISIONS
POLARIZED BEAMS
THALLIUM
UNIFIED GAUGE MODELS
WEAK NEUTRAL CURRENTS
WEINBERG-SALAM GAUGE MODEL