http://hdl.handle.net/20.500.12128/13530
Title: | New limits on neutrino non-unitary mixings based on prescribed singular values |
Authors: | Flieger, Wojciech Gluza, Janusz Porwit, Kamil |
Keywords: | Neutrino Physics; Beyond Standard Model |
Issue Date: | 2020 |
Citation: | "Journal of High Energy Physics" Vol. 2020, iss. 3 (2020), art. no 169 |
Abstract: | Singular values are used to construct physically admissible 3-dimensional mix- ing matrices characterized as contractions. Depending on the number of singular values strictly less than one, the space of the 3-dimensional mixing matrices can be split into four disjoint subsets, which accordingly corresponds to the minimal number of additional, non-standard neutrinos. We show in numerical analysis that taking into account present experimental precision and fits to different neutrino mass splitting schemes, it is not pos- sible to distinguish, on the level of 3-dimensional mixing matrices, between two and three extra neutrino states. It means that in 3+2 and 3+3 neutrino mixing scenarios, using the so-called α parametrization, ranges of non-unitary mixings are the same. However, on the level of a complete unitary 3+1 neutrino mixing matrix, using the dilation procedure and the Cosine-Sine decomposition, we were able to shrink bounds for the \light-heavy" mixing matrix elements. For instance, in the so-called seesaw mass scheme, a new upper limit on jUe4j is about two times stringent than before and equals 0.021. For all considered mass schemes the lowest bounds are also obtained for all mixings, i.e. |Ue4|, |Uμ4|, |Uτ4|. New results obtained in this work are based on analysis of neutrino mixing matrices obtained from the global fits at the 95% CL. |
URI: | http://hdl.handle.net/20.500.12128/13530 |
DOI: | 10.1007/JHEP03(2020)169 |
ISSN: | 1029-8479 |
Appears in Collections: | Artykuły (WNŚiT) |
File | Description | Size | Format | |
---|---|---|---|---|
Flieger_New_Limits_On_Neutrino_Non-unitary_Mixing_Based_On_Prescribed_Singular_Values.pdf | 2,78 MB | Adobe PDF | View/Open |
Uznanie Autorstwa 3.0 Polska Creative Commons License