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Author |
Meloni, D.; Morisi, S.; Peinado, E. |
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Title |
Neutrino phenomenology and stable dark matter with A(4) |
Type |
Journal Article |
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Year |
2011 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
697 |
Issue |
4 |
Pages |
339-342 |
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Keywords |
Flavor symmetries; Dark matter; Neutrino masses; Lepton mixing; Discrete symmetries; Neutrino less double beta decay |
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Abstract |
We present a model based on the A(4) non-Abelian discrete symmetry leading to a predictive five-parameter neutrino mass matrix and providing a stable dark matter candidate. We found an interesting correlation among the atmospheric and the reactor angles which predicts theta(23) similar to pi/4for very small reactor angle and deviation from maximal atmospheric mixing for large theta(13). Only normal neutrino mass spectrum is possible and the effective mass entering the neutrinoless double beta decay rate is constrained to be vertical bar m(ee)vertical bar > 4 x 10(-4) eV. |
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Address |
[Morisi, S.; Peinado, E.] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, E-46071 Valencia, Spain, Email: davide.meloni@physik.uni-wuerzburg.de |
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Publisher  |
Elsevier Science Bv |
Place of Publication |
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Language |
English |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Expedition |
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Conference |
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Notes |
ISI:000288300400012 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
544 |
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Author |
NEMO-3 Collaboration (Argyriades, J. et al); Diaz, J.; Martin-Albo, J.; Monrabal, F.; Novella, P.; Serra, L.; Yahlali, N. |
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Title |
Spectral modeling of scintillator for the NEMO-3 and SuperNEMO detectors |
Type |
Journal Article |
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Year |
2011 |
Publication |
Nuclear Instruments & Methods in Physics Research A |
Abbreviated Journal |
Nucl. Instrum. Methods Phys. Res. A |
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Volume |
625 |
Issue |
1 |
Pages |
20-28 |
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Keywords |
Scintillation; Photomultiplier; Plastic scintillators; Optical photon transport; GEANT 4; Double beta decay |
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Abstract |
We have constructed a GEANT4-based detailed software model of photon transport in plastic sontillator blocks and have used it to study the NEMO-3 and SuperNEMO calorimeters employed in experiments designed to search for neutnnoless double beta decay We compare our simulations to measurements using conversion electrons from a calibration source of (BI)-B-207 and show that the agreement is improved if wavelength-dependent properties of the calorimeter are taken into account In this article we briefly describe our modeling approach and results of our studies. |
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Address |
[Lang, K.; Pahlka, R. B.] Univ Texas Austin, Dept Phys, Austin, TX 78712 USA |
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Elsevier Science Bv |
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English |
Summary Language |
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Original Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0168-9002 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000285432400004 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
587 |
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Author |
Freitas, E.D.C.; Monteiro, C.M.B.; Ball, M.; Gomez-Cadenas, J.J.; Lopes, J.A.M.; Lux, T.; Sanchez, F.; dos Santos, J.M.F. |
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Title |
Secondary scintillation yield in high-pressure xenon gas for neutrinoless double beta decay (0 nu beta beta) search |
Type |
Journal Article |
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Year |
2010 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
684 |
Issue |
4-5 |
Pages |
205-210 |
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Keywords |
Neutrino; Neutrinoless double-beta decay; Secondary scintillation; Xenon; High-pressure |
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Abstract |
The search for neutrinoless double beta decay (0 nu beta beta) is an important topic in contemporary physics with many active experiments. New projects are planning to use high-pressure xenon gas as both source and detection medium. The secondary scintillation processes available in noble gases permit large amplification with negligible statistical fluctuations, offering the prospect of energy resolution approaching the Fano factor limit. This Letter reports results for xenon secondary scintillation yield, at room temperature, as a function of electric field in the gas scintillation gap for pressures ranging from 2 to 10 bar. A Large Area Avalanche Photodiode (LAAPD) collected the VUV secondary scintillation produced in the gas. X-rays directly absorbed in the LAAPD are used as a reference for determining the number of charge carriers produced by the scintillation pulse and, hence, the number of photons impinging the LAAPD. The number of photons produced per drifting electron and per kilovolt, the so-called scintillation amplification parameter, displays a small increase with pressure, ranging from 141 +/- 6 at 2 bar to 170 +/- 10 at 8 bar. In our setup, this Parameter does not increase above 8 bar due to nonnegligible electron attachment. The results are in good agreement with those presented in the literature in the 1 to 3 bar range. The increase of the scintillation amplification parameter with pressure for high gas densities has been also observed in former work at cryogenic temperatures. |
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Address |
[Freitas, E. D. C.; Monteiro, C. M. B.; Lopes, J. A. M.; dos Santos, J. M. F.] Univ Coimbra, GIAN CI, Dept Fis, P-3004516 Coimbra, Portugal, Email: jmf@gian.fis.uc.pt |
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Corporate Author |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000275009600006 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
487 |
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Author |
Fujita, Y.; Rubio, B.; Gelletly, W. |
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Title |
Spin-isospin excitations probed by strong, weak and electro-magnetic interactions |
Type |
Journal Article |
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Year |
2011 |
Publication |
Progress in Particle and Nuclear Physics |
Abbreviated Journal |
Prog. Part. Nucl. Phys. |
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Volume |
66 |
Issue |
3 |
Pages |
549-606 |
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Keywords |
Gamow-Teller transitions; beta decay; Charge-exchange reactions; Isospin symmetry; High resolution; Proton-rich nuclei |
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Abstract |
Gamow-Teller (GT) transitions are the most common weak interaction processes of spin-isospin (sigma tau) type in atomic nuclei. They are of interest not only in nuclear physics but also in astrophysics; they play an important role in supernovae explosions and nucleosynthesis. The direct study of weak decay processes, however, gives relatively limited information about GT transitions and the states excited via GT transitions (GT states); beta decay can only access states at excitation energies lower than the decay Q-value, and neutrino-induced reactions have very small cross-sections. However, one should note that beta decay has a direct access to the absolute GT transition strengths B(GT) from a study of half-lives, Q(beta)-values and branching ratios. They also provide information on GT transitions in nuclei far-from-stability. Studies of M1 gamma transitions provide similar information. In contrast, the complementary charge-exchange (CE) reactions, such as the (p, n) or ((3)He, t) reactions at intermediate beam energies and 0 degrees, can selectively excite GT states up to high excitation energies in the final nucleus. It has been found empirically that there is a close proportionality between the cross-sections at 0 degrees and the transition strengths B(GT) in these CE reactions. Therefore, CE reactions are useful tools to study the relative values of B(GT) strengths up to high excitation energies. In recent ((3)He, t) measurements, one order-of-magnitude improvement in the energy resolution has been achieved. This has made it possible to make one-to-one comparisons of GT transitions studied in CE reactions and beta decays. Thus GT strengths in ((3)He, t) reactions can be normalised by the beta-decay values. In addition, comparisons with closely related M1 transitions studied in gamma decay or electron inelastic scattering [(e, e')1, and furthermore with “spin” M I transitions that can be studied by proton inelastic scattering [(p, p')[ have now been made possible. In these comparisons, the isospin quantum number T and associated symmetry structure in the same mass A nuclei (isobars) play a key role. Isospin symmetry can extend our scope even to the structures of unstable nuclei that are far from reach at present unstable beam factories. |
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Address |
[Fujita, Y] Osaka Univ, Dept Phys, Osaka 5600043, Japan, Email: fujita@rcnp.osaka-u.ac.jp |
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Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0146-6410 |
ISBN |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000292473100003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
692 |
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Author |
Morisi, S.; Peinado, E. |
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Title |
Admixture of quasi-Dirac and Majorana neutrinos with tri-bimaximal mixing |
Type |
Journal Article |
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Year |
2011 |
Publication |
Physics Letters B |
Abbreviated Journal |
Phys. Lett. B |
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Volume |
701 |
Issue |
4 |
Pages |
451-457 |
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Keywords |
Neutrinoless double beta decay; Neutrino masses and mixings; Flavor symmetries; Tri-bimaximal mixing; Neutrino hierarchy; Discrete symmetries |
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Abstract |
We propose a realization of the so-called bimodal/schizophrenic model proposed recently. We assume 54, the permutation group of four objects as flavor symmetry giving tri-bimaximal lepton mixing at leading order. In these models the second massive neutrino state is assumed quasi-Dirac and the remaining neutrinos are Majorana states. In the case of inverse mass hierarchy, the lower bound on the neutrinoless double beta decay parameter m(ee) is about two times that of the usual lower bound, within the range of sensitivity of the next generation of experiments. |
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Address |
[Morisi, S; Peinado, E] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, E-46071 Valencia, Spain, Email: morisi@ific.uv.es |
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Corporate Author |
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Thesis |
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Publisher |
Elsevier Science Bv |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0370-2693 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000292994100011 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
700 |
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| Permanent link to this record |
