Title: Perturbing neutrino oscillations around the solar resonance

Abstract

Atmospheric neutrinos at low energies, $$E \lesssim 500$$ MeV, are known to be a rich source of information on lepton mixing parameters. We formulate a simple perturbative framework to elucidate the characteristic features of neutrino oscillation at around the solar-scale enhancement due to the matter effect. The clearest message that we could extract from our perturbation theory is that CP violation in the appearance oscillation probability is large, a factor of $$\sim 10$$ times larger than CP violation at around the atmospheric-scale oscillation maximum. The underlying mechanism for this is that one of the suppression factors on the CP phase-dependent terms due to the smallness of $$\Delta m^2_{21} / \Delta m^2_{31}$$ is dynamically lifted by the solar-scale enhancement. Our framework has a unique feature as a perturbation theory in which a large $$\Delta m^2_{31}$$ term outside the key 1-2 sector for the solar-scale resonance does not yield sizable corrections. On the contrary, the larger the $$\Delta m^2_{31}$$, the smaller the higher-order corrections.

Authors:

Martinez-Soler, Ivan ^[1]; Minakata, Hisakazu ^[2]

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+ Show Author Affiliations

1. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States). Theoretical Physics Dept.; Northwestern Univ., Evanston, IL (United States). Dept. of Physics and Astronomy; Colegio de Física Fundamental e Interdisciplinaria de las Américas (COFI), San Juan (Puerto Rico)
2. Virginia Tech, Blacksburg, VA (United States). Dept. of Physics, Center for Neutrino Physics; Univ. of Tokyo, Kashiwa, Chiba (Japan). Inst. for Cosmic Ray Research, Research Center for Cosmic Neutrinos

Publication Date:

2019-07-29

Research Org.:

Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

Sponsoring Org.:

USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)

OSTI Identifier:

1545096

Report Number(s):

arXiv:1904.07853; FERMILAB-PUB-19-149-T; NUHEP-TH/19-05
Journal ID: ISSN 2050-3911; 1730033

Grant/Contract Number:  

AC02-07CH11359

Resource Type:

Accepted Manuscript

Journal Name:

Progress of Theoretical and Experimental Physics

Additional Journal Information:

Journal Volume: 2019; Journal Issue: 7; Journal ID: ISSN 2050-3911

Publisher:

Physical Society of Japan

Country of Publication:

United States

Language:

English

Subject:

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS