Precise Measurement of Parity Nonconserving Optical Rotation in Atomic Thallium

Edwards, N.H. ; Phipp, S.J. ; Baird, P.E.G. ; et al.
Phys.Rev.Lett. 74 (1995) 2654-2657, 1995.
Inspire Record 943148 DOI 10.17182/hepdata.19660

We report a new measurement of parity nonconserving (PNC) optical rotation on the 6p1/2- 6p3/2 transition in atomic thallium near 1283 nm. The result expressed in terms of the quantity R=Im{E1PNC/M1} is −(15.68±0.45)×10−8, and is consistent with current calculations based on the standard model. In addition, limits have been set on the much smaller nuclear spin-dependent rotation amplitude at RS=(0.04±0.20)×10−8; this is consistent with theoretical estimates which include a nuclear anapole contribution.

1 data table

Spin of the Tl nucleus is 1/2.


Experimental verification of the Kramers-Kronig relation at high energy

Alvensleben, H. ; Becker, U. ; Biggs, P.J. ; et al.
Phys.Rev.Lett. 30 (1973) 328-332, 1973.
Inspire Record 84536 DOI 10.17182/hepdata.21393

The real part of the forward amplitude for Compton scattering on protons was measured through the interference between the Compton and Bethe-Heithler amplitudes by detecting the zero-degree electron pairs asymmetrically. The measurement was made at an average photon energy of 〈k〉=2.2 GeV, and an average momentum transfer to the recoil proton 〈t〉=−0.027 (GeV/c)2. The result confirms the prediction of the Kramers-Kronig relation.

1 data table

No description provided.