New Limit of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="italic">G</mi></math>-Parity Irregular Weak Nucleon Current Disclosed in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>β</mi></math>-Ray Angular Distributions from Spin Aligned <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>B</mi></mrow><mprescripts></mprescripts><mrow></mrow><mrow><mn>12</mn></mrow><mrow></mrow><mrow></mrow></mmultiscripts></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mmultiscripts><mrow><mi>N</mi></mrow><mprescripts></mprescripts><mrow></mrow><mrow><mn>12</mn></mrow><mrow></mrow><mrow></mrow></mmultiscripts></mrow></math>

T. Minamisono; K. Matsuta; T. Yamaguchi; K. Minamisono; T. Ikeda; Y. Muramoto; M. Fukuda; Y. Nojiri; A. Kitagawa; K. Koshigiri; M. Morita

doi:10.1103/PhysRevLett.80.4132

New Limit of the $G$ -Parity Irregular Weak Nucleon Current Disclosed in $β$ -Ray Angular Distributions from Spin Aligned ${}^{12}B$ and ${}^{12}N$

T. Minamisono, K. Matsuta, T. Yamaguchi, K. Minamisono, T. Ikeda, Y. Muramoto, M. Fukuda, Y. Nojiri, A. Kitagawa, K. Koshigiri, and M. Morita

Phys. Rev. Lett. 80, 4132 – Published 11 May 1998

Abstract

The angular distributions of $β$ rays from spin aligned ${}^{12}B$ and ${}^{12}N$ were precisely remeasured using a further refined spin-manipulation technique. Our old data have also been recorrected for precisely determined systematic corrections. A nonzero $G$ -parity violating induced tensor form factor $f_{T}$ has been concluded as ${2 M f}_{T} {/ f}_{A} = + 0.22 \pm 0.05 (stat) \pm 0.15 (syst) \pm 0.05 (theor .)$ . In this result the asymmetry in the axial charges due to the binding-energy difference of the transforming nucleons is taken into account.

Received 14 August 1997

DOI:https://doi.org/10.1103/PhysRevLett.80.4132

Authors & Affiliations

T. Minamisono^1,*, K. Matsuta¹, T. Yamaguchi¹, K. Minamisono¹, T. Ikeda¹, Y. Muramoto¹, M. Fukuda¹, Y. Nojiri¹, A. Kitagawa², K. Koshigiri³, and M. Morita⁴

¹Department of Physics, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560, Japan
²National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263, Japan
³Department of Physics, Osaka Kyoiku University, Kashiwara 582, Japan
⁴Department of Physics, Josai International University, 1 Gumyo, Togane, Chiba 283, Japan