2001/02/28 by Takahiro Miura, Eiichi Takasugi, Y. Kuno +2 · 3 citations
Physics and Astronomy · #Dark Matter and Cosmic Phenomena #Neutrino Physics Research #Particle physics theoretical and experimental studies #hep-ex #hep-ph
paper · pdf · doi:10.1103/physrevd.64.013002
published as Phys.Rev. D64 (2001) 013002 · Latex, 30 pages, 6 figures
arxiv created 2001/03/21 · openalex publication_date 2001/05/21 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We analyze T violation in neutrino oscillations by using perturbation methods with respect to \ensuremathΔm212L/2E and \ensuremathδa(x)L/2E, where \ensuremathδa(x) represents the matter density fluctuation from its average value. We find that the matter contribution to T violation arises from interference between \ensuremathΔm212L/2E and \ensuremathδa(x)L/2E. To second order, the symmetric and asymmetric matter density fluctuations give effects to the sin\ensuremathδ (intrinsic) and the cos\ensuremathδ (fake) parts of T violation. We give their analytic forms and analyze the matter contribution to the sin\ensuremathδ and cos\ensuremathδ terms. We find that, for L=3000 km, both the symmetric and asymmetric matter density fluctuations give negligible contributions to T violation and that thus the constant (average) matter density gives a good approximation. On the other hand, we argue that, for L=7000 km or longer, T violation turns out to become very small due to the cancellation between the first and second order terms. This shows that the constant (average) matter approximation is not valid.