|   | 
Details
   web
Records
Author del Aguila, F.; Aparici, A.; Bhattacharya, S.; Santamaria, A.; Wudka, J.
Title A realistic model of neutrino masses with a large neutrinoless double beta decay rate Type Journal Article
Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 05 Issue 5 Pages 133 - 30pp
Keywords Neutrino Physics; Higgs Physics; Beyond Standard Model
Abstract The minimal Standard Model extension with the Weinberg operator does accommodate the observed neutrino masses and mixing, but predicts a neutrinoless double beta (0 nu beta beta) decay rate proportional to the effective electron neutrino mass, which can be then arbitrarily small within present experimental limits. However, in general 0 nu beta beta decay can have an independent origin and be near its present experimental bound; whereas neutrino masses are generated radiatively, contributing negligibly to 0 nu beta beta decay. We provide a realization of this scenario in a simple, well defined and testable model, with potential LHC effects and calculable neutrino masses, whose two-loop expression we derive exactly. We also discuss the connection of this model to others that have appeared in the literature, and remark on the significant differences that result from various choices of quantum number assignments and symmetry assumptions. In this type of models lepton flavor violating rates are also preferred to be relatively large, at the reach of foreseen experiments. Interestingly enough, in our model this stands for a large third mixing angle, sin(2) theta(13) greater than or similar to 0.008, when μ-> eee is required to lie below its present experimental limit.
Address [del Aguila, Francisco] Univ Granada, CAFPE, E-18071 Granada, Spain, Email: faguila@ugr.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 (up)
Notes WOS:000305238600053 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1092
Permanent link to this record
 

 
Author Semikoz, V.B.; Sokoloff, D.D.; Valle, J.W.F.
Title Lepton asymmetries and primordial hypermagnetic helicity evolution Type Journal Article
Year 2012 Publication Journal of Cosmology and Astroparticle Physics Abbreviated Journal J. Cosmol. Astropart. Phys.
Volume 06 Issue 6 Pages 008 - 12pp
Keywords Magnetohydrodynamics; galactic magnetic fields; cosmic magnetic fields theory; particle physics – cosmology connection
Abstract The hypermagnetic helicity density at the electroweak phase transition (EWPT) exceeds many orders of magnitude the galactic magnetic helicity density. Together with previous magnetic helicity evolution calculations after the EWPT and hypermagnetic helicity conversion to the magnetic one at the EWPT, the present calculation completes the description of the evolution of this important topological feature of cosmological magnetic fields. It suggests that if the magnetic field seeding the galactic dynamo has a primordial origin, it should be substantially helical. This should be taken into account in scenarios of galactic magnetic field evolution with a cosmological seed.
Address [Semikoz, V. B.; Valle, J. W. F.] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, E-46071 Valencia, Spain, Email: semikoz@ific.uv.es;
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 1475-7516 ISBN Medium
Area Expedition Conference (up)
Notes WOS:000306003500008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1101
Permanent link to this record
 

 
Author Li, X.Q.; Li, Y.M.; Lu, G.R.; Su, F.
Title B-s(0)-(B)over-bar(s)(0) mixing in a family non-universal Z ' model revisited Type Journal Article
Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 05 Issue 5 Pages 049 - 27pp
Keywords Beyond Standard Model; B-Physics; CP violation
Abstract Motivated by the very recent measurements performed at the LHCb and the Tevatron of the B-s(0) – (B) over bar (0)(s) mixing, in this paper we revisit it in a family non-universal Z' model, to check if a simultaneous explanation for all the mixing observables, especially for the like-sign dimuon charge asymmetry observed by the D0 collaboration, could be made in such a specific model. In the first scenario where the Z' boson contributes only to the off-diagonal element M-12(s), it is found that, once the combined constraints from Delta M-s, phi(s) and Delta Gamma(s) are imposed, the model could not explain the measured flavour-specific CP asymmetry a(fs)(s), at least within its 1 sigma ranges. In the second scenario where the NP contributes also to the absorptive part Gamma(s)(12) via tree-level Z'-induced b -> c (c) over bars operators, we find that, with the constraints from Delta M-s, phi(s) and the indirect CP asymmetry in (B) over bar (d) -> J/psi K-S taken into account, the present measured 1 sigma experimental ranges for a(fs)(s) could not be reproduced too. Thus, such a specific Z' model with our specific assumptions could not simultaneously reconcile all the present data on B-s(0) – B-s(0) mixing. Future improved measurements from the LHCb and the proposed superB experiments, especially of the flavour-specific CP asymmetries, are expected to shed light on the issue.
Address [Li, Xin-Qiang; Li, Yan-Min; Lu, Gong-Ru] Henan Normal Univ, Dept Phys, Xinxiang 453007, Henan, Peoples R China, Email: xqli@itp.ac.cn;
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 (up)
Notes WOS:000305236000049 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1103
Permanent link to this record
 

 
Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title Search for Point-like Sources of Ultra-high Energy Neutrinos at the Pierre Auger Observatory and Improved Limit on the Diffuse Flux of Tau Neutrinos Type Journal Article
Year 2012 Publication Astrophysical Journal Letters Abbreviated Journal Astrophys. J. Lett.
Volume 755 Issue 1 Pages L4 - 7pp
Keywords astroparticle physics; cosmic rays; neutrinos; telescopes
Abstract The surface detector array of the Pierre Auger Observatory can detect neutrinos with energy E-nu between 10(17) eV and 10(20) eV from point-like sources across the sky south of +55 degrees and north of -65 degrees declinations. A search has been performed for highly inclined extensive air showers produced by the interaction of neutrinos of all flavors in the atmosphere (downward-going neutrinos), and by the decay of tau leptons originating from tau neutrino interactions in Earth's crust (Earth-skimming neutrinos). No candidate neutrinos have been found in data up to 2010 May 31. This corresponds to an equivalent exposure of similar to 3.5 years of a full surface detector array for the Earth-skimming channel and similar to 2 years for the downward-going channel. An improved upper limit on the diffuse flux of tau neutrinos has been derived. Upper limits on the neutrino flux from point-like sources have been derived as a function of the source declination. Assuming a differential neutrino flux k(PS) . E-nu(-2). from a point-like source, 90% confidence level upper limits for k(PS) at the level of approximate to 5x10(-7) and 2.5x10(-6) GeV cm(-2) s(-1) have been obtained over a broad range of declinations from the searches for Earth-skimming and downward-going neutrinos, respectively.
Address [Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Diogo, F.; Espadanal, J.; Goncalves, P.; Pimenta, M.; Santo, C. E.; Santos, E.; Tome, B.] Univ Tecn Lisboa, LIP, Lisbon, Portugal
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 2041-8205 ISBN Medium
Area Expedition Conference (up)
Notes WOS:000306930700004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1121
Permanent link to this record
 

 
Author Coloma, P.; Donini, A.; Fernandez-Martinez, E.; Hernandez, P.
Title Precision on leptonic mixing parameters at future neutrino oscillation experiments Type Journal Article
Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 06 Issue 6 Pages 073 - 27pp
Keywords Neutrino Physics; CP violation; Standard Model
Abstract We perform a comparison of the different future neutrino oscillation experiments based on the achievable precision in the determination of the fundamental parameters theta(13) and the CP phase, delta, assuming that theta(13) is in the range indicated by the recent Daya Bay measurement. We study the non-trivial dependence of the error on delta on its true value. When matter effects are small, the largest error is found at the points where CP violation is maximal, and the smallest at the CP conserving points. The situation is different when matter effects are sizable. As a result of this effect, the comparison of the physics reach of different experiments on the basis of the CP discovery potential, as usually done, can be misleading. We have compared various proposed super-beam, beta-beam and neutrino factory setups on the basis of the relative precision of theta(13) and the error on delta. Neutrino factories, both high-energy or low-energy, outperform alternative beam technologies. An ultimate precision on theta(13) below 3% and an error on delta of <= 7 degrees at 1 sigma (1 d.o.f.) can be obtained at a neutrino factory.
Address [Coloma, P.] Virginia Tech, Dept Phys, Ctr Neutrino Phys, Blacksburg, VA 24061 USA, Email: coloma@vt.edu;
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 (up)
Notes WOS:000306416500074 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1141
Permanent link to this record