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Author (up) Esteves, J.N.; Joaquim, F.R.; Joshipura, A.S.; Romao, J.C.; Tortola, M.; Valle, J.W.F. url  doi
openurl 
  Title A(4)-based neutrino masses with Majoron decaying dark matter Type Journal Article
  Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 82 Issue 7 Pages 073008 - 8pp  
  Keywords  
  Abstract We propose an A(4) flavor-symmetric SU(3) circle times SU(2) circle times U(1) seesaw model where lepton number is broken spontaneously. A consistent two-zero texture pattern of neutrino masses and mixing emerges from the interplay of type-I and type-II seesaw contributions, with important phenomenological predictions. We show that, if the Majoron becomes massive, such seesaw scenario provides a viable candidate for decaying dark matter, consistent with cosmic microwave background lifetime constraints that follow from current WMAP observations. We also calculate the subleading one-loop-induced decay into photons which leads to a monoenergetic emission line that may be observed in future x-ray missions such as Xenia.  
  Address [Esteves, J. N.; Romao, J. C.] Inst Super Tecn, Dept Fis, P-1049001 Lisbon, Portugal, Email: joaomest@cftp.ist.utl.pt  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000282812200004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 360  
Permanent link to this record
 

 
Author (up) Esteves, J.N.; Romao, J.C.; Hirsch, M.; Vicente, A.; Porod, W.; Staub, F. url  doi
openurl 
  Title LHC and lepton flavour violation phenomenology of a left-right extension of the MSSM Type Journal Article
  Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 12 Issue 12 Pages 077 - 44pp  
  Keywords Supersymmetry Phenomenology  
  Abstract We study the phenomenology of a supersymmetric left-right model, assuming minimal supergravity boundary conditions. Both left-right and (B-L) symmetries are broken at an energy scale close to, but significantly below the GUT scale. Neutrino data is explained via a seesaw mechanism. We calculate the RGEs for superpotential and soft parameters complete at 2-loop order. At low energies lepton flavour violation (LFV) and small, but potentially measurable mass splittings in the charged scalar lepton sector appear, due to the RGE running. Different from the supersymmetric “pure seesaw” models, both, LFV and slepton mass splittings, occur not only in the left-but also in the right slepton sector. Especially, ratios of LFV slepton decays, such as Br((tau) over bar (R) -> μchi(0)(1))/Br((tau) over bar (L) -> μchi(0)(1)) are sensitive to the ratio of (B-L) and left-right symmetry breaking scales. Also the model predicts a polarization asymmetry of the outgoing positrons in the decay mu(+) -> e(+)gamma, A similar to [0, 1], which differs from the pure seesaw “prediction” A = 1. Observation of any of these signals allows to distinguish this model from any of the three standard, pure (mSugra) seesaw setups.  
  Address [Esteves, J. N.; Romao, J. C.] Inst Super Tecn, Dept Fis, P-1049001 Lisbon, Portugal, Email: joaomest@cftp.ist.utl.pt  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000285964200015 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 532  
Permanent link to this record
 

 
Author (up) Fernandes, L.M.P.; Freitas, E.D.C.; Ball, M.; Gomez-Cadenas, J.J.; Monteiro, C.M.B.; Yahlali, N.; Nygren, D.; dos Santos, J.M.F. url  doi
openurl 
  Title Primary and secondary scintillation measurements in a Xenon Gas Proportional Scintillation Counter Type Journal Article
  Year 2010 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.  
  Volume 5 Issue Pages P09006 - 15pp  
  Keywords Interaction of radiation with matter; Gaseous detectors; Photon detectors for UV, visible and IR photons (vacuum) (photomultipliers, HPDs, others)  
  Abstract NEXT is a new experiment to search for neutrinoless double beta decay using a 100 kg radio-pure high-pressure gaseous xenon TPC. The detector requires excellent energy resolution, which can be achieved in a Xe TPC with electroluminescence readout. Hamamatsu R8520-06SEL photomultipliers are good candidates for the scintillation readout. The performance of this photomultiplier, used as VUV photosensor in a gas proportional scintillation counter, was investigated. Initial results for the detection of primary and secondary scintillation produced as a result of the interaction of 5.9 keV X-rays in gaseous xenon, at room temperature and at pressures up to 3 bar, are presented. An energy resolution of 8.0% was obtained for secondary scintillation produced by 5.9 keV X-rays. No significant variation of the primary scintillation was observed for different pressures (1, 2 and 3 bar) and for electric fields up to 0.8 V cm(-1) torr(-1) in the drift region, demonstrating negligible recombination luminescence. A primary scintillation yield of 81 +/- 7 photons was obtained for 5.9 keV X-rays, corresponding to a mean energy of 72 +/- 6 eV to produce a primary scintillation photon in xenon.  
  Address [Fernandes, L. M. P.; Freitas, E. D. C.; Monteiro, C. M. B.; dos Santos, J. M. F.] Univ Coimbra, Dept Phys, Instrumentat Ctr, P-3004516 Coimbra, Portugal, Email: pancho@gian.fis.uc.pt  
  Corporate Author Thesis  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1748-0221 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000283796100003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 255  
Permanent link to this record
 

 
Author (up) Fernandez-Carames, T.; Valcarce, A.; Vijande, J. doi  openurl
  Title Charged charmonium molecules Type Journal Article
  Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 82 Issue 5 Pages 054032 - 5pp  
  Keywords  
  Abstract We make use of a self-consistent quark-model based study of four-quark charmonium-like states to interpret recent charmonium experimental data. We conclude that there exists a D*(D) over bar* meson-meson molecule with quantum numbers (I-G) J(PC) = (1(-))2(++). Our study confirms the presence of charged charmonium-like resonances on the excited charmonium spectrum. We find support from recent experimental data by the Belle Collaboration [R. Mizuk et al. (Belle Collaboration), Phys. Rev. D 78, 072004 (2008)]. Confirmation of the experimental data by the Belle Collaboration and the determination of the quantum numbers of the new structures would help in discriminating among different theoretical models and would give further support to the theoretical analysis of T. Fernandez-Carames, A. Valcarce, and J. Vijande [Phys. Rev. Lett. 103, 222001 (2009)].  
  Address [Carames, T. F.; Valcarce, A.] Univ Salamanca, Dept Fis Fundamental, E-37008 Salamanca, Spain  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000282271100006 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 366  
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Author (up) Fernandez-Martinez, E.; Giordano, G.; Mena, O.; Mocioiu, I. url  doi
openurl 
  Title Atmospheric neutrinos in ice and measurement of neutrino oscillation parameters Type Journal Article
  Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 82 Issue 9 Pages 093011 - 7pp  
  Keywords  
  Abstract The main goal of the IceCube Deep Core array is to search for neutrinos of astrophysical origins. Atmospheric neutrinos are commonly considered as a background for these searches. We show that the very high statistics atmospheric neutrino data can be used to obtain precise measurements of the main oscillation parameters.  
  Address [Fernandez-Martinez, Enrique] Werner Heisenberg Inst, Max Planck Inst Phys, D-80805 Munich, Germany  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000284259000002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 332  
Permanent link to this record
 

 
Author (up) Fernandez-Martinez, E.; Li, T.; Pascoli, S.; Mena, O. url  doi
openurl 
  Title Improvement of the low energy neutrino factory Type Journal Article
  Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 81 Issue 7 Pages 073010 - 13pp  
  Keywords  
  Abstract The low energy neutrino factory has been proposed as a very sensitive setup for future searches for CP violation and matter effects. Here we study how its performance is affected when the experimental specifications of the setup are varied. Most notably, we have considered the addition of the “platinum'' nu(mu) -> nu(e) channel. We find that, while theoretically the extra channel provides very useful complementary information and helps to lift degeneracies, its practical usefulness is lost when considering realistic background levels. Conversely, an increase in statistics in the ”golden'' nu(mu) -> nu(e) channel and, to some extent, an improvement in the energy resolution, lead to an important increase in the performance of the facility, given the rich energy dependence of the "golden'' channel at these energies. We show that a low energy neutrino factory with a baseline of 1300 km, muon energy of 4.5 GeV, and either a 20 kton totally active scintillating detector or 100 kton liquid argon detector, can have outstanding sensitivity to the neutrino oscillation parameters theta(13), delta, and the mass hierarchy. For our estimated exposure of 2: 8 x 10(23) kton x decays per muon polarity, the low energy neutrino factory has sensitivity to theta(13) and delta for sin(2)(2 theta(13)) > 10(-4) and to the mass hierarchy for sin(2)(2 theta(13)) > 10(-3)  
  Address [Martinez, Enrique Fernandez] Max Planck Inst Phys & Astrophys, Werner Heisenberg Inst, D-80805 Munich, Germany, Email: enfmarti@mppmu.mpg.de  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000277201900018 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 458  
Permanent link to this record
 

 
Author (up) Ferrario, P.; Rodrigo, G. url  doi
openurl 
  Title Heavy colored resonances in t(t)over-bar + jet at the LHC Type Journal Article
  Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 02 Issue 2 Pages 051 - 13pp  
  Keywords QCD Phenomenology  
  Abstract The LHC is the perfect environment for the study of new physics in the top quark sector. We study the possibility of detecting signals of heavy color-octet vector resonances, through the charge asymmetry, in t (t) over bar + jet events. Besides contributions with the t (t) over bar pair in a color-singlet state, the asymmetry gets also contributions which are proportional to the color factor f(abc)(2). This process is particularly interesting for extra-dimensional models, where the inclusive charge asymmetry generated by Kaluza-Klein excitations of the gluon vanishes at the tree level. We find that the statistical significance for the measurement of such an asymmetry is sizable for different values of the coupling constants and already at low energies.  
  Address [Ferrario, Paola; Rodrigo, German] UVEG, Consejo Super Invest Cient, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: paola.ferrario@ific.uv.es  
  Corporate Author Thesis  
  Publisher Springer Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000275223100051 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ elepoucu @ Serial 483  
Permanent link to this record
 

 
Author (up) Fileviez Perez, P.; Iminniyaz, H.; Rodrigo, G.; Spinner, S. url  doi
openurl 
  Title Gauge mediated supersymmetry breaking via seesaw mechanisms Type Journal Article
  Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 81 Issue 9 Pages 095013 - 12pp  
  Keywords  
  Abstract We present a simple scenario for gauge mediated supersymmetry breaking (GMSB) where the messengers are also the fields that generate neutrino masses. We show that the simplest such scenario corresponds to the case where neutrino masses are generated through the type I and type III seesaw mechanisms. The entire supersymmetric spectrum and Higgs masses are calculable from only four input parameters. Since the electroweak symmetry is broken through a doubly radiative mechanism, meaning a nearly zero B term at the messenger scale which runs down to acceptable values, one obtains quite a constrained spectrum for the supersymmetric particles whose properties we describe. We refer to this mechanism as "nu GMSB.''  
  Address [Perez, Pavel Fileviez; Spinner, Sogee] Univ Wisconsin, Dept Phys, Madison, WI 53706 USA  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000278145100073 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 440  
Permanent link to this record
 

 
Author (up) Fogli, G.L.; Lisi, E.; Palazzo, A.; Rotunno, A.M. url  doi
openurl 
  Title Combined analysis of KamLAND and Borexino neutrino signals from Th and U decays in the Earth's interior Type Journal Article
  Year 2010 Publication Physical Review D Abbreviated Journal Phys. Rev. D  
  Volume 82 Issue 9 Pages 093006 - 9pp  
  Keywords  
  Abstract The KamLAND and Borexino experiments have detected electron antineutrinos produced in the decay chains of natural thorium and uranium (Th and U geoneutrinos). We analyze the energy spectra of current geoneutrino data in combination with solar and long-baseline reactor neutrino data, with marginalized three-neutrino oscillation parameters. We consider the case with unconstrained Th and U event rates in KamLAND and Borexino, as well as cases with fewer degrees of freedom, as obtained by successively assuming for both experiments a common Th/U ratio, a common scaling of Th + U event rates, and a chondritic Th/U value. In combination, KamLAND and Borexino can reject the null hypothesis (no geoneutrino signal) at 5 sigma. Interesting bounds or indications emerge on the Th + U geoneutrino rates and on the Th/U ratio, in broad agreement with typical Earth model expectations. Conversely, the results disfavor the hypothesis of a georeactor in the Earth's core, if its power exceeds a few TW. The interplay of KamLAND and Borexino geoneutrino data is highlighted.  
  Address [Fogli, G. L.; Rotunno, A. M.] Dipartimento Interateneo Fis Michelangelo Merlin, I-70126 Bari, Italy  
  Corporate Author Thesis  
  Publisher Amer Physical Soc Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1550-7998 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000284144900001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 331  
Permanent link to this record
 

 
Author (up) 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. doi  openurl
  Title Secondary scintillation yield in high-pressure xenon gas for neutrinoless double beta decay (0 nu beta beta) search Type Journal Article
  Year 2010 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 684 Issue 4-5 Pages 205-210  
  Keywords Neutrino; Neutrinoless double-beta decay; Secondary scintillation; Xenon; High-pressure  
  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.  
  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  
  Corporate Author Thesis  
  Publisher Elsevier Science Bv Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0370-2693 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000275009600006 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 487  
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