New results on P -odd asymmetry of -quanta emission in 10B(n,)7Li + 7Li(g.s.) nuclear reaction

• Published in: The European physical journal. A, Hadrons and nuclei Hadrons and nuclei, 2011, Vol.47 (3)
• Main Authors: Vesna, V. A., Gledenov, Yu. M., Nesvizhevsky, V. V., Sedyshev, P. V., Shulgina, E. V.
• Format: Article
• Language: English
• Subjects: Hadrons; Heavy Ions; Nuclear Fusion; Nuclear Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Regular Article - Experimental Physics
• ISSN: 1434-6001; 1434-601X
• DOI: 10.1140/epja/i2011-11043-2

. A series of ultra-sensitive experiments has been carried out in 2001-2009 at the ILL measuring P -odd asymmetry in -quanta emission in the nuclear reaction 10 B ( n , ) 7 Li * + $ 7 Li$(g.s.) with polarized cold neutrons. The resulting value of the asymmetry coefficient is . These experiments profited from high-intensity PF1B neutron facility and a new version of the integral measuring method: for decreasing experimental uncertainties, the frequency of neutron spin-flip was higher than a typical reactor power noise frequency. Using the new value, we constrain the weak neutral current constant in the cluster model framework to (at 90% c.l.). This constraint agrees with that following from the nuclear reaction 6 Li ( n , ) 3 H : (at 90% c.l.). However, they both contradict the “best” value in the quark model by Desplanques, Donoughe, and Holstein . We invite experts in the field to contribute to the theoretical analysis of the problem.