Measurement of P-odd asymmetry of γ-quanta emission in the nuclear reaction 10B(n,α)7Li*→γ+7Li(g.s.)

✍ Scribed by V.A. Vesna; Yu.M. Gledenov; V.V. Nesvizhevsky; A.K. Petukhov; P.V. Sedyshev; E.V. Shul’gina

• Publisher: Elsevier Science
• Year: 2009
• Tongue: English
• Weight: 168 KB
• Volume: 611
• Category: Article
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2009.07.067

✦ Synopsis

We present results of measurement of the P-odd asymmetry a P-odd of g-quanta emission in the nuclear reaction 10 B(n,a) 7 Li * -g+ 7 Li(g.s.) with polarized cold neutrons. The experiment was carried out using a new version of the integral measuring method. The frequency of neutron spin-flip is higher in this method than the typical reactor power noise frequency; this condition decreases experimental uncertainties. The result is a 10 B P-odd ¼ þð0:873:9Þ Â 10 À8 ; ''zero'' experiments are taken into account. Using this value, we constrain the weak neutral current constant in the framework of the cluster model to f 10 B p r2:4 Â 10 À7 (at 90% c.l.). This constraint does not contradict the estimation obtained from the nuclear reaction 6 Li(n,a) 3 H: f 6 Li p r1:1 Â 10 À7 (at 90% c.l.). However, both these constraints contradict the ''best'' value of the Quark model by Desplanques, Donoughe, and Holstein f DDH p ¼ 4:6 Â 10 À7 .