Determining neutrino mass hierarchy by precision measurements in electron and muon neutrino disappearance experiments
Determining neutrino mass hierarchy by precision measurements in electron and muon neutrino disappearance experiments
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DOI：
10.1103/physrevd.74.053008
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发表时间：
2006-07
影响因子：
5
通讯作者：
H. Minakata;H. Nunokawa;S. Parke;R. Funchal
中科院分区：
文献类型：
--
作者：
H. Minakata;H. Nunokawa;S. Parke;R. Funchal
Recently a new method for determining the neutrino mass hierarchy by comparing the effective values of the atmospheric {Delta}m{sup 2} measured in the electron neutrino disappearance channel, {Delta}m{sup 2}(ee), with the one measured in the muon neutrino disappearance channel, {Delta}m{sup 2}({mu}{mu}), was proposed. If {Delta}m{sup 2}(ee) is larger (smaller) than {Delta}m{sup 2} ({mu}{mu}) the hierarchy is of the normal (inverted) type. We re-examine this proposition in the light of two very high precision measurements: {Delta}m{sup 2}({mu}{mu}) that may be accomplished by the phase II of the Tokai-to-Kamioka (T2K) experiment, for example, and {Delta}m{sup 2}(ee) that can be envisaged using the novel Moessbauer enhanced resonant {bar {nu}}{sub e} absorption technique. Under optimistic assumptions for the systematic uncertainties of both measurements, we estimate the parameter region of ({theta}{sub 13}, {delta}) in which the mass hierarchy can be determined. If {theta}{sub 13} is relatively large, sin{sup 2} 2{theta}{sub 13} {approx}> 0.05, and both of {Delta}m{sup 2}(ee) and {Delta}m{sup 2}({mu}{mu}) can be measured with the precision of {approx} 0.5 % it is possible to determine the neutrino mass hierarchy at > 95% CL for 0.3{pi} {approx}< {delta} {approx}< 1.7 {pi} for the current best fit values of all the other oscillation parameters.
Recently a new method for determining the neutrino mass hierarchy by comparing the effective values of the atmospheric {Delta}m{sup 2} measured in the electron neutrino disappearance channel, {Delta}m{sup 2}(ee), with the one measured in the muon neutrino disappearance channel, {Delta}m{sup 2}({mu}{mu}), was proposed. If {Delta}m{sup 2}(ee) is larger (smaller) than {Delta}m{sup 2} ({mu}{mu}) the hierarchy is of the normal (inverted) type. We re-examine this proposition in the light of two very high precision measurements: {Delta}m{sup 2}({mu}{mu}) that may be accomplished by the phase II of the Tokai-to-Kamioka (T2K) experiment, for example, and {Delta}m{sup 2}(ee) that can be envisaged using the novel Moessbauer enhanced resonant {bar {nu}}{sub e} absorption technique. Under optimistic assumptions for the systematic uncertainties of both measurements, we estimate the parameter region of ({theta}{sub 13}, {delta}) in which the mass hierarchy can be determined. If {theta}{sub 13} is relatively large, sin{sup 2} 2{theta}{sub 13} {approx}> 0.05, and both of {Delta}m{sup 2}(ee) and {Delta}m{sup 2}({mu}{mu}) can be measured with the precision of {approx} 0.5 % it is possible to determine the neutrino mass hierarchy at > 95% CL for 0.3{pi} {approx}< {delta} {approx}< 1.7 {pi} for the current best fit values of all the other oscillation parameters.