Solar models and solar neutrino oscillations

We provide a summary of the current knowledge, theoretical and experimental, of solar neutrino fluxes and of the masses and mixing angles that characterize solar neutrino oscillations. We also summarize the principal reasons for doing new solar neutrino experiments and what we think may be learned from the future measurements.Comment: Submitted to the Neutrino Focus Issue of New Journal of Physics at http://www.njp.or

What can we learn from neutrinoless double beta decay experiments?

We assess how well next generation neutrinoless double beta decay and normal neutrino beta decay experiments can answer four fundamental questions. 1) If neutrinoless double beta decay searches do not detect a signal, and if the spectrum is known to be inverted hierarchy, can we conclude that neutrinos are Dirac particles? 2) If neutrinoless double beta decay searches are negative and a next generation ordinary beta decay experiment detects the neutrino mass scale, can we conclude that neutrinos are Dirac particles? 3) If neutrinoless double beta decay is observed with a large neutrino mass element, what is the total mass in neutrinos? 4) If neutrinoless double beta decay is observed but next generation beta decay searches for a neutrino mass only set a mass upper limit, can we establish whether the mass hierarchy is normal or inverted? We base our answers on the expected performance of next generation neutrinoless double beta decay experiments and on simulations of the accuracy of calculations of nuclear matrix elements.Comment: Added reference

Double Beta Decay

We review recent developments in double-beta decay, focusing on what can be learned about the three light neutrinos in future experiments. We examine the effects of uncertainties in already measured neutrino parameters and in calculated nuclear matrix elements on the interpretation of upcoming double-beta decay measurements. We then review a number of proposed experiments.Comment: Some typos corrected, references corrected and added. A less blurry version of figure 3 is available from authors. 41 pages, 5 figures, submitted to J. Phys.

If sterile neutrinos exist, how can one determine the total solar neutrino fluxes?

The 8 B solar neutrino flux inferred from a global analysis of solar neutrino experiments is within 11% (1 s) of the predicted standard solar model value if only active neutrinos exist, but could be as large as 1.7 times the standard prediction if sterile neutrinos exist. We show that the total 8 B neutrino flux ~active plus sterile neutrinos! can be determined experimentally to about 10% (1s) by combining charged current measurements made with the KamLAND reactor experiment and with the SNO CC solar neutrino experiment, provided the LMA neutrino oscillation solution is correct and the simulated performance of KamLAND is valid. Including also SNO NC data, the sterile component of the 8 B neutrino flux can be measured by this method to an accuracy of about 12% (1s) of the standard solar model flux. Combining Super-Kamiokande and KamLAND measurements and assuming the oscillations occur only among active neutrinos, the 8 B neutrino flux can be measured to 6% (1s); the total flux can be measured to an accuracy of about 9%. The total 7 Be solar neutrino flux can be determined to an accuracy of about 28% (1 s) by combining measurements made with the KamLAND, SNO, and gallium neutrino experiments. One can determine the total 7 Be neutrino flux to a 1 s accuracy of about 11% or better by comparing data from the KamLAND experiment and the BOREXINO solar neutrino experiment provided both detectors work as expected. The pp neutrino flux can be determined to about 15% using data from the gallium, KamLAND, BOREXINO, and SNO experiments