IFIC Home

IFIC Literature Database

Home |  Show All |  Simple Search |  Advanced Search
Quick Search:
31-40 of 280 records found matching your query:
toggle visibility Search & Display Options
Select All    Deselect All << 1 2 3 4 5 6 7 8 9 10 >> [11–20]
List View
 | 
Citations
 | 
Details
   print
  Records Links
Author Chang, Q.; Li, X.Q.; Yang, Y.D. url  doi
openurl 
  Title (down) The effects of a family nonuniversal Z ' boson on B -> pi pi decays Type Journal Article
  Year 2011 Publication International Journal of Modern Physics A Abbreviated Journal Int. J. Mod. Phys. A  
  Volume 26 Issue 7-8 Pages 1273-1294  
  Keywords B-physics; rare decays; beyond Standard Model  
  Abstract Motivated by the measured large branching ratio of (B) over bar (0) --> pi(0)pi(0) (the so-called pi pi puzzle), we investigate the effects of a family nonuniversal Z' model on the tree-dominated B --> pi pi decays. We find that the Z' coupling parameter zeta(LR)(d) similar to 0.05 with a nontrivial new weak phase phi(L)(d) similar to -50 degrees, which is relevant to the Z' contributions to the QCD penguin sector Delta C-5, is needed to reconcile the observed discrepancy. Combined with the recent fitting results from B --> pi K, pi K* and rho K decays, the Z' parameter spaces are severely reduced but still not excluded entirely, implying that both the “pi pi” and “pi K” puzzles could be accommodated simultaneously within such a family nonuniversal Z' model.  
  Address [Chang, Qin; Li, Xin-Qiang] Henan Normal Univ, Dept Phys, Xinxiang 453007, Henan, Peoples R China, Email: changqin@htu.cn  
  Corporate Author Thesis  
  Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0217-751x ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000289175800004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 595  
Permanent link to this record
 
 
Author Escudero, M.; Witte, S.J.; Rius, N. url  doi
openurl 
  Title (down) The dispirited case of gauged U(1)(B-L) dark matter Type Journal Article
  Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 08 Issue 8 Pages 190 - 30pp  
  Keywords Beyond Standard Model; Cosmology of Theories beyond the SM  
  Abstract We explore the constraints and phenomenology of possibly the simplest scenario that could account at the same time for the active neutrino masses and the dark matter in the Universe within a gauged U(1)(B-L) symmetry, namely right-handed neutrino dark matter. We find that null searches from lepton and hadron colliders require dark matter with a mass below 900 GeV to annihilate through a resonance. Additionally, the very strong constraints from high-energy dilepton searches fully exclude the model for 150 GeV < m(z') < 3 TeV. We further explore the phenomenology in the high mass region (i.e. masses greater than or similar to O(1) TeV) and highlight theoretical arguments, related to the appearance of a Landau pole or an instability of the scalar potential, disfavoring large portions of this parameter space. Collectively, these considerations illustrate that a minimal extension of the Standard Model via a local U(1)(B-L) symmetry with a viable thermal dark matter candidate is difficult to achieve without fine-tuning. We conclude by discussing possible extensions of the model that relieve tension with collider constraints by reducing the gauge coupling required to produce the correct relic abundance.  
  Address [Escudero, Miguel] Univ Valencia, CSIC, Dept Fis Teor, C Catedrat Jose Beltran 2, E-46980 Paterna, Spain, Email: Miguel.Escudero@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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000443008100006 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 3706  
Permanent link to this record
 
 
Author Cosme, C.; Dutra, M.; Godfrey, S.; Gray, T. url  doi
openurl 
  Title (down) Testing freeze-in with axial and vector Z ' bosons Type Journal Article
  Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 09 Issue 9 Pages 056 - 27pp  
  Keywords Beyond Standard Model; Cosmology of Theories beyond the SM  
  Abstract The freeze-in production of Feebly Interacting Massive Particle (FIMP) dark matter in the early universe is an appealing alternative to the well-known – and constrained – Weakly Interacting Massive Particle (WIMP) paradigm. Although challenging, the phenomenology of FIMP dark matter has been receiving growing attention and is possible in a few scenarios. In this work, we contribute to this endeavor by considering a Z ' portal to fermionic dark matter, with the Z ' having both vector and axial couplings and a mass ranging from MeV up to PeV. We evaluate the bounds on both freeze-in and freeze-out from direct detection, atomic parity violation, leptonic anomalous magnetic moments, neutrino-electron scattering, collider, and beam dump experiments. We show that FIMPs can already be tested by most of these experiments in a complementary way, whereas WIMPs are especially viable in the Z ' low mass regime, in addition to the Z ' resonance region. We also discuss the role of the axial couplings of Z ' in our results. We therefore hope to motivate specific realizations of this model in the context of FIMPs, as well as searches for these elusive dark matter candidates.  
  Address [Cosme, Catarina; Dutra, Maira; Godfrey, Stephen; Gray, Taylor] Carleton Univ, Ottawa Carleton Inst Phys, 1125 Colonel By Dr, Ottawa, ON K1S 5B6, Canada, Email: catarina.cosme@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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000695081900001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4962  
Permanent link to this record
 
 
Author Hernandez, P.; Kekic, M.; Lopez-Pavon, J.; Racker, J.; Salvado, J. url  doi
openurl 
  Title (down) Testable baryogenesis is in seesaw models Type Journal Article
  Year 2016 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 08 Issue 8 Pages 157 - 29pp  
  Keywords Cosmology of Theories beyond the SM; CP violation; Neutrino Physics; Beyond Standard Model  
  Abstract We revisit the production of baryon asymmetries in the minimal type I seesaw model with heavy Majorana singlets in the GeV range. In particular we include “washout” effects from scattering processes with gauge bosons, Higgs decays and inverse decays, besides the dominant top scatterings. We show that in the minimal model with two singlets, and for an inverted light neutrino ordering, future measurements from SHiP and neutrinoless double beta decay could in principle provide sufficient information to predict the matter-antimatter asymmetry in the universe. We also show that SHiP measurements could provide very valuable information on the PMNS CP phases.  
  Address [Hernandez, P.; Kekic, M.; Racker, J.; Salvado, J.] Univ Valencia, Inst Fis Corpuscular, Edificio Inst Invest,Catedrat Jose Beltran 2, Valencia 46980, Spain, Email: m.pilar.hernandez@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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000382398000004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2787  
Permanent link to this record
 
 
Author Bonnet, F.; Hirsch, M.; Ota, T.; Winter, W. url  doi
openurl 
  Title (down) Systematic study of the d=5 Weinberg operator at one-loop order Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 153 - 23pp  
  Keywords Beyond Standard Model; Neutrino Physics  
  Abstract We perform a systematic study of the d = 5 Weinberg operator at the one-loop level. We identify three different categories of neutrino mass generation: (1) finite irreducible diagrams; (2) finite extensions of the usual seesaw mechanisms at one-loop and (3) divergent loop realizations of the seesaws. All radiative one-loop neutrino mass models must fall in to one of these classes. Case (1) gives the leading contribution to neutrino mass naturally and a classic example of this class is the Zee model. We demonstrate that in order to prevent that a tree level contribution dominates in case (2), Majorana fermions running in the loop and an additional Z(2) symmetry are needed for a genuinely leading one-loop contribution. In the type-II loop extensions, the Yukawa coupling will be generated at one loop, whereas the type-I/III extensions can be interpreted as loop-induced inverse or linear seesaw mechanisms. For the divergent diagrams in category (3), the tree level contribution cannot be avoided and is in fact needed as counter term to absorb the divergence.  
  Address [Bonnet, Florian; Winter, Walter] Univ Wurzburg, Inst Theoret Phys & Astrophys, D-97074 Wurzburg, Germany, Email: florian.bonnet@physik.uni-wuerzburg.de;  
  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 WOS:000307299800031 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1159  
Permanent link to this record
 
 
Author Bonnet, F.; Hirsch, M.; Ota, T.; Winter, W. url  doi
openurl 
  Title (down) Systematic decomposition of the neutrinoless double beta decay operator Type Journal Article
  Year 2013 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 03 Issue 3 Pages 055 - 34pp  
  Keywords Beyond Standard Model; Neutrino Physics  
  Abstract We discuss the systematic decomposition of the dimension nine neutrinoless double beta decay operator, focusing on mechanisms with potentially small contributions to neutrino mass, while being accessible at the LHC. We first provide a (d = 9 tree-level) complete list of diagrams for neutrinoless double beta decay. From this list one can easily recover all previously discussed contributions to the neutrinoless double beta decay process, such as the celebrated mass mechanism or “exotics”, such as contributions from left-right symmetric models, R-parity violating supersymmetry and leptoquarks. More interestingly, however, we identify a number of new possibilities which have not been discussed in the literature previously. Contact to earlier works based on a general Lorentz-invariant parametrisation of the neutrinoless double beta decay rate is made, which allows, in principle, to derive limits on all possible contributions. We furthermore discuss possible signals at the LHC for mediators leading to the short-range part of the amplitude with one specific example. The study of such contributions would gain particular importance if there were a tension between different measurements of neutrino mass such as coming from neutrinoless double beta decay and cosmology or single beta decay.  
  Address Univ Wurzburg, Inst Theoret Phys & Astrophys, D-97074 Wurzburg, Germany, Email: florian.bonnet@physik.uni-wuerzburg.de;  
  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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000317521200055 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1416  
Permanent link to this record
 
 
Author Aristizabal Sierra, D.; Degee, A.; Dorame, L.; Hirsch, M. url  doi
openurl 
  Title (down) Systematic classification of two-loop realizations of the Weinberg operator Type Journal Article
  Year 2015 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 03 Issue 3 Pages 040 - 41pp  
  Keywords Beyond Standard Model; Neutrino Physics  
  Abstract We systematically analyze the d = 5 Weinberg operator at 2-loop order. Using a diagrammatic approach, we identify two different interesting categories of neutrino mass models: (i) Genuine 2-loop models for which both, tree-level and 1-loop contributions, are guaranteed to be absent. And (ii) finite 2-loop diagrams, which correspond to the 1-loop generation of some particular vertex appearing in a given 1-loop neutrino mass model, thus being effectively 2-loop. From the large list of all possible 2-loop diagrams, the vast majority are infinite corrections to lower order neutrino mass models and only a moderately small number of diagrams fall into these two interesting classes. Moreover, all diagrams in class (i) are just variations of three basic diagrams, with examples discussed in the literature before. Similarly, we also show that class (ii) diagrams consists of only variations of these three plus two more basic diagrams. Finally, we show how our results can be consistently and readily used in order to construct two-loop neutrino mass models.  
  Address [Sierra, D. Aristizabal; Degee, A.] Univ Liege, IFPA, Dept AGO, B-4000 Liege 1, Belgium, Email: daristizabal@ulg.ac.be;  
  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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000351365700002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2167  
Permanent link to this record
 
 
Author Centelles Chulia, S.; Cepedello, R.; Peinado, E.; Srivastava, R. url  doi
openurl 
  Title (down) Systematic classification of two-loop d=4 Dirac neutrino mass models and the Diracness-dark matter stability connection Type Journal Article
  Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 10 Issue 10 Pages 093 - 33pp  
  Keywords Beyond Standard Model; Neutrino Physics  
  Abstract We provide a complete systematic classification of all two-loop realizations of the dimension four operator for Dirac neutrino masses. Our classification is multi-layered, starting first with a classification in terms of all possible distinct two loop topologies. Then we discuss the possible diagrams for each topology. Model-diagrams originating from each diagram are then considered. The criterion for genuineness is also defined and discussed at length. Finally, as examples, we construct two explicit models which also serve to highlight the intimate connection between the Dirac nature of neutrinos and the stability of dark matter.  
  Address [Chulia, Salvador Centelles; Cepedello, Ricardo; Srivastava, Rahul] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Parc Cient Paterna,C Catedrat Jose Beltran 2, E-46980 Valencia, Spain, Email: salcen@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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000491092500001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4181  
Permanent link to this record
 
 
Author Cepedello, R.; Fonseca, R.M.; Hirsch, M. url  doi
openurl 
  Title (down) Systematic classification of three-loop realizations of the Weinberg operator Type Journal Article
  Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 10 Issue 10 Pages 197 - 34pp  
  Keywords Beyond Standard Model; Neutrino Physics  
  Abstract We study systematically the decomposition of the Weinberg operator at three-loop order. There are more than four thousand connected topologies. However, the vast majority of these are infinite corrections to lower order neutrino mass diagrams and only a very small percentage yields models for which the three-loop diagrams are the leading order contribution to the neutrino mass matrix. We identify 73 topologies that can lead to genuine three-loop models with fermions and scalars, i.e. models for which lower order diagrams are automatically absent without the need to invoke additional symmetries. The 73 genuine topologies can be divided into two sub-classes: normal genuine ones (44 cases) and special genuine topologies (29 cases). The latter are a special class of topologies, which can lead to genuine diagrams only for very specific choices of fields. The genuine topologies generate 374 diagrams in the weak basis, which can be reduced to only 30 distinct diagrams in the mass eigenstate basis. We also discuss how all the mass eigenstate diagrams can be described in terms of only five master integrals. We present some concrete models and for two of them we give numerical estimates for the typical size of neutrino masses they generate. Our results can be readily applied to construct other d = 5 neutrino mass models with three loops.  
  Address [Cepedello, Ricardo; Hirsch, Martin] Univ Valencia, CSIC, AHEP Grp, Inst Fis Corpuscular, Edificio Inst Paterna,Apartado 22085, E-46071 Valencia, Spain, Email: ricepe@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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000449260800013 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3792  
Permanent link to this record
 
 
Author Bustamante, M.; Gago, A.M.; Jones Perez, J. url  doi
openurl 
  Title (down) SUSY renormalization group effects in ultra high energy neutrinos Type Journal Article
  Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 05 Issue 5 Pages 133 - 26pp  
  Keywords Neutrino Physics; Supersymmetric Standard Model; Renormalization Group  
  Abstract We have explored the question of whether the renormalization group running of the neutrino mixing parameters in the Minimal Supersymmetric Standard Model is detectable with ultra-high energy neutrinos from active galactic nuclei (AGN). We use as observables the ratios of neutrino fluxes produced at the AGN, focusing on four different neutrino production models: (Phi(0)(v epsilon+(v) over bar epsilon) : Phi(0)(v mu+(v) over bar mu) : Phi(0)(v tau+(v) over bar tau)) = (1 : 2 : 0), (0 : 1 : 0), (1 : 0 : 0), and (1 : 1 : 0). The prospects for observing deviations experimentally are taken into consideration, and we find out that it is necessary to impose a cut-off on the transferred momentum of Q(2) >= 10(7) GeV(2). However, this condition, together with the expected low value of the diffuse AGN neutrino flux, yields a negligible event rate at a km-scale. Cerenkov detector such as IceCube.  
  Address [Bustamante, M; Gago, AM] Pontificia Univ Catolica Peru, Dept Ciencias, Sec Fis, Lima, Peru, Email: mbustamante@pucp.edu.pe  
  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 WOS:000291364500065 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 684  
Permanent link to this record
Select All    Deselect All << 1 2 3 4 5 6 7 8 9 10 >> [11–20]
List View
 | 
Citations
 | 
Details
   print
toggle visibility
Save Citations:
Export Records:
Home CQL Search  |  Library Search  |  Show Record  |  Extract Citations Help
ific federMinisterio de Ciencia e InnovaciónAgencia Estatal de Investigaciongva