Neutrinoless Double Beta Decay within QRPA with Proton-Neutron Pairing

We have investigated the role of proton-neutron pairing in the context of the Quasiparticle Random Phase approximation formalism. This way the neutrinoless double beta decay matrix elements of the experimentally interesting A= 48, 76, 82, 96, 100, 116, 128, 130 and 136 systems have been calculated. We have found that the inclusion of proton-neutron pairing influences the neutrinoless double beta decay rates significantly, in all cases allowing for larger values of the expectation value of light neutrino masses. Using the best presently available experimental limits on the half life-time of neutrinoless double beta decay we have extracted the limits on lepton number violating parameters.Comment: 16 RevTex page

Additional Nucleon Current Contributions to Neutrinoless Double Beta Decay

We have examined the importance of momentum dependent induced nucleon currents such as weak-magnetism and pseudoscalar couplings to the amplitude of neutrinoless double beta decay in the mechanisms of light and heavy Majorana neutrino as well as in that of Majoron emission. Such effects are expected to occur in all nuclear models in the direction of reducing the light neutrino matrix elements by about 30%. To test this we have performed a calculation of the nuclear matrix elements of the experimentally interesting nuclei A = 76, 82, 96, 100, 116, 128, 130, 136 and 150 within the pn-RQRPA. We have found that indeed such corrections vary somewhat from nucleus to nucleus, but in all cases they are greater than 25 percent. In the case of heavy neutrino the effect is much larger (a factor of 3). Combining out results with the best presently available experimental limits on the half-life of the neutrinoless double beta decay we have extracted new limits on the effective neutrino mass (light and heavy) and the effective Majoron coupling constant.Comment: 31 pages, RevTex, 3 Postscript figures, submitted to Phys. Rev.

Recent advances in neutrinoless double beta decay search

Even after the discovery of neutrino flavour oscillations, based on data from atmospheric, solar, reactor, and accelerator experiments, many characteristics of the neutrino remain unknown. Only the neutrino square-mass differences and the mixing angle values have been estimated, while the value of each mass eigenstate still hasn't. Its nature (massive Majorana or Dirac particle) is still escaping. Neutrinoless double beta decay ($0\nu$-DBD) experimental discovery could be the ultimate answer to some delicate questions of elementary particle and nuclear physics. The Majorana description of neutrinos allows the $0\nu$-DBD process, and consequently either a mass value could be measured or the existence of physics beyond the standard should be confirmed without any doubt. As expected, the $0\nu$-DBD measurement is a very difficult field of application for experimentalists. In this paper, after a short summary of the latest results in neutrino physics, the experimental status, the R&D projects, and perspectives in $0\nu$-DBD sector are reviewed.Comment: 36 pages, 7 figures, To be publish in Czech Journal of Physic

Neutrinoless Double Beta Decay of Ge76, Se82, Mo100 and Xe136 to excited 0^+ states

The neutrinoless double beta decay transition to the first excited 0^+ collective final state is examined for A=76, 82, 100 and 136 nuclei by assuming light and heavy Majorana neutrino exchange mechanisms as well as the trilinear R-parity violating contributions. Realistic calculations of nuclear matrix elements have been performed within the renormalized quasiparticle random phase approximation. Transitions to the first excited two-quadrupole phonon 0^+ state are described within a boson expansion formalism and alternatively by using the operator recoupling method. We present the sensitivity parameters to different lepton number violating signals, which can be used in planning the neutrinoless double beta decay experiments. The half-life of neutrinoless double beta decay to the first excited state 0^+_1 is by a factor of 10 to 100 larger than that of the transition to the ground state.Comment: 31 pages, RevTex, 1 Postscript figures, to appear in Phys. Rev.

Emissions from incineration of fluoropolymer materials. A literature survey.

The Norwegian Pollution Control Authority (SFT) commissioned a literature survey on incineration of fluoropolymer materials, overviewing the available literature on formation of greenhouse gases until August 2008. The survey provides the foundation on which decisions for the future needs for further investigations will be made. Suggestions for sampling were also part of the study