Non-Unitary Neutrino Mixing in the NOνA Near Detector Data

Universe

卷:8

Soebur Razzaque¹  Ushak Rahaman¹ 

[1] Centre for Astro-Particle Physics (CAPP), Department of Physics, University of Johannesburg, P.O. Box 524, Auckland Park, Johannesburg 2006, South Africa;

关键词: neutrino oscillation;    non-unitary mixing;    BSM;    mass hierarchy;    CP violation;   

DOI  :  10.3390/universe8040238

来源: DOAJ

【 摘 要 】

The ${\nu }_{\mu }\to {\nu }_e$ oscillation probability over a short baseline (≲1 km) would be negligible for the case when the mixing matrix for three active neutrinos is unitary. However, in the case of a non-unitary mixing of three neutrinos, this probability would be non-negligible due to the so-called “zero distance” effect. Hence, the near detector of accelerator experiments such as NO$\nu$A can provide strong constraints on the parameters of the non-unitary mixing with very large statistics. By analyzing the NO$\nu$A near-detector data, we find that the non-unitary mixing does not improve fits to the ${\nu }_e$ or ${\nu }_{\mu }$ events over the standard unitary mixing. This leads to constraints on the non-unitary parameters: ${\alpha }_{00}>0.911$, $|{\alpha }_{10}|<0.020$, and ${\alpha }_{11}>0.952$ at 90% C.L. A combined analysis with the near- and far-detector data does not change these constraints significantly.

【 授权许可】

Unknown