Majorana neutrinos, neutrino mass spectrum, and the |<m>|{approx}10{sup -3} eV frontier in neutrinoless double beta decay
- IPPP, Department of Physics, Durham University, Durham, DH1 3LE (United Kingdom)
If future neutrino oscillation experiments show that the neutrino mass spectrum is with normal ordering, m{sub 1}<m{sub 2}<m{sub 3}, and the searches for neutrinoless double beta [({beta}{beta}){sub 0{nu}}] decay with sensitivity to values of the effective Majorana mass |<m>| > or approx. 10{sup -2} eV give negative results, the next frontier in the quest for ({beta}{beta}){sub 0{nu}}-decay will correspond to |<m>|{approx}10{sup -3} eV. By assuming that massive neutrinos are Majorana particles and their exchange is the dominant mechanism generating ({beta}{beta}){sub 0{nu}}-decay, we analyze the conditions under which |<m>|, in the case of three-neutrino mixing and a neutrino mass spectrum with normal ordering, would satisfy |<m>|{>=}0.001 eV. We consider the specific cases of (i) a normal hierarchical neutrino mass spectrum, (ii) a relatively small value of the CHOOZ angle {theta}{sub 13}, as well as (iii) the general case of a spectrum with normal ordering, a partial hierarchy, and a value of {theta}{sub 13} close to the existing upper limit. We study the ranges of the lightest neutrino mass m{sub 1} and/or of sin{sup 2}{theta}{sub 13} for which |<m>|{>=}0.001 eV and discuss the phenomenological implications of such scenarios. We provide also an estimate of |<m>| when the three-neutrino masses and the neutrino mixing originate from a neutrino mass term of the Majorana type for the (left-handed) flavor neutrinos and {sub j}{sup 3}m{sub j}U{sub ej}{sup 2}=0, but there does not exist a symmetry which forbids the ({beta}{beta}){sub 0{nu}}-decay.
- OSTI ID:
- 21205048
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 77, Issue 11; Other Information: DOI: 10.1103/PhysRevD.77.113003; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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