2004/07/31 by D. Indumathi, M. V. N. Murthy · 1 citation
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #CP violation #Calorimeter (particle physics) #Detector #Muon #Neutrino #Neutrino Physics Research #Neutrino oscillation #Nuclear physics #Oscillation (cell signaling) #Particle physics #Particle physics theoretical and experimental studies #Physics #hep-ph
paper · pdf · doi:10.1103/physrevd.71.013001
published as Phys.Rev. D71 (2005) 013001 · 36 pages revtex with 14 eps figures; new section on statistical significance when detector resolution is included
arxiv created 2004/12/06 · openalex publication_date 2005/01/03 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
It is by now established that neutrinos mix, have (different) nonzero masses, and therefore oscillate. The oscillation parameters themselves, however, are not all well-known. An open problem is that of the neutrino mass hierarchy. We study the possibility of determining the neutrino mass hierarchy with atmospheric neutrinos using an iron calorimeter detector capable of charge identification such as the proposed monolith and ical/ino detectors. We find that such detectors are sensitive to the sign of the mass-squared difference, \ensuremathδ32=m32\ensuremath-m22, provided the as-yet unknown mixing angle between the first and third generations, \ensuremathθ13, is greater than 6\ifmmode^∘\else\textdegree\fi (sin22\ensuremathθ13>0.04). A result with a significance greater than 90% CL requires large exposures (more than 500 kton-years) as well as good energy and angular resolution of the detected muons (better than 15%), especially for small \ensuremathθ13. Hence obtaining definitive results with such a detector is difficult, unless \ensuremathθ13 turns out to be large. In contrast, such detectors can establish a clear oscillation pattern in atmospheric neutrinos in about 150 kton-years, therefore determining the absolute value of \ensuremathδ32 and sin22\ensuremathθ23 to within 10%.