BEAMING NEUTRINOS AND ANTI-NEUTRINOS ACROSS THE EARTH TO DISENTANGLE NEUTRINO MIXING PARAMETERS

Journal Article · Wed Oct 10 00:00:00 EDT 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/758/1/3· OSTI ID:22092130

Fargion, Daniele; D'Armiento, Daniele; Paggi, Paolo ^[1]; Desiati, Paolo ^[2]

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1. Physics Department, Rome University 1, P.le A Moro 5, I-00185 Rome (Italy)
2. Department of Physics, University of Wisconsin-Madison, 1150 University Avenue Madison, WI 53706 (United States)

A result from MINOS seemed to indicate that the mass splitting and mixing angle of anti-neutrinos is different from that of neutrinos, suggesting a charge-parity-time (CPT) violation in the lepton sector. However, more recent MINOS data reduced the {nu}{sub {mu}}-{nu}-bar{sub {mu}} differences leading to a narrow discrepancy nearly compatible with no CPT violation. However, the last few years of OPERA activity on the appearance of a tau lepton (one unique event) still has not been probed and more tools may be required to disentangle a list of parameters ({mu}-{tau} flavor mixing, tau appearance, any eventual CPT violation, {theta}{sub 13} angle value, and any hierarchy neutrino mass). Atmospheric anisotropy in muon neutrino spectra in the DeepCore, at ten to tens of GeV (unpublished), can hardly reveal asymmetry in the eventual {nu}{sub {mu}}-{nu}-bar{sub {mu}} oscillation parameters. Here we considered how the longest baseline neutrino oscillation available, crossing most of Earth's diameter, may improve the measurement and at best disentangle any hypothetical CPT violation occurring between the earliest (2010) and the present (2012) MINOS bounds (with 6{sigma} a year), while testing {tau} and even the appearance of {tau}-bar at the highest rate. The {nu}{sub {mu}} and {nu}-bar{sub {mu}} disappearance correlated with the tau appearance is considered for those events at the largest distances. We thus propose a beam of {nu}{sub {mu}} and {nu}-bar{sub {mu}} crossing through the Earth, within an OPERA-like experiment from CERN (or Fermilab), in the direction of the IceCube-DeepCore {nu} detector at the South Pole. The ideal energy lies at 21 GeV to test the disappearance or (for any tiny CPT violation) the partial {nu}-bar{sub {mu}} appearance. Such a tuned detection experiment may lead to a strong signature of {tau} or {tau}-bar generation even within its neutral current noise background events: nearly one {tau}-bar or two {tau} a day. The tau appearance signal is above (or within) 10{sigma} a year, even for a 1% OPERA-like experiment. Peculiar configurations for {theta}{sub 13} and the hierarchy neutrino mass test may also be better addressed by a DeepCore-PINGU array detector beaming {nu}{sub {mu}} and observing {nu}{sub e} at 6 GeV neutrino energy windows.

• OSTI ID: 22092130
• Journal Information: Astrophysical Journal, Vol. 758, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ANISOTROPY
ANTINEUTRINOS
ASYMMETRY
COSMIC NEUTRINOS
CPT THEOREM
FERMILAB
FLAVOR MODEL
GEV RANGE
MULTIPARTICLE SPECTROMETERS
MUON NEUTRINOS
NEUTRAL CURRENTS
NEUTRINO OSCILLATION
NUCLEOSYNTHESIS
PARITY
PARTICLE IDENTIFICATION
REST MASS
SYMMETRY BREAKING
TAU PARTICLES
WEINBERG ANGLE