TY - JOUR
T1 - Naturalness of nearly degenerate neutrinos
AU - Casas, J. A.
AU - Espinosa, J. R.
AU - Ibarra, A.
AU - Navarro, I.
N1 - Funding Information:
We thank D. Casper and E. Kearns for clarification of the results of Super-Kamiokande fits. This research was supported in part by the CICYT (contract AEN95-0195) and the European Union (contract CHRX-CT92-0004) (JAC). J.R.E. thanks the I.E.M. (CSIC, Spain) and A.I, I.N the CERN Theory Division, for hospitality during the final stages of this work.
PY - 1999/9/6
Y1 - 1999/9/6
N2 - If neutrinos are to play a relevant cosmological role, they must be essentially degenerate. We study whether radiative corrections can or cannot be responsible for the small mass splittings, in agreement with all the available experimental data. We perform an exhaustive exploration of the bimaximal mixing scenario, finding that (i) the vacuum oscillations solution to the solar neutrino problem is always excluded; (ii) if the mass matrix is produced by a see-saw mechanism, there are large regions of the parameter space consistent with the large angle MSW solution, providing a natural origin for the △m2sol ≪ △m2atm hierarchy; (iii) the bimaximal structure becomes then stable under radiative corrections. We also provide analytical expressions for the mass splittings and mixing angles and present a particularly simple see-saw ansatz consistent with all observations.
AB - If neutrinos are to play a relevant cosmological role, they must be essentially degenerate. We study whether radiative corrections can or cannot be responsible for the small mass splittings, in agreement with all the available experimental data. We perform an exhaustive exploration of the bimaximal mixing scenario, finding that (i) the vacuum oscillations solution to the solar neutrino problem is always excluded; (ii) if the mass matrix is produced by a see-saw mechanism, there are large regions of the parameter space consistent with the large angle MSW solution, providing a natural origin for the △m2sol ≪ △m2atm hierarchy; (iii) the bimaximal structure becomes then stable under radiative corrections. We also provide analytical expressions for the mass splittings and mixing angles and present a particularly simple see-saw ansatz consistent with all observations.
UR - http://www.scopus.com/inward/record.url?scp=0033530058&partnerID=8YFLogxK
U2 - 10.1016/S0550-3213(99)00383-1
DO - 10.1016/S0550-3213(99)00383-1
M3 - Article
AN - SCOPUS:0033530058
SN - 0550-3213
VL - 556
SP - 3
EP - 22
JO - Nuclear Physics, Section B
JF - Nuclear Physics, Section B
IS - 1-2
ER -