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Author del Aguila, F.; Aparici, A.; Bhattacharya, S.; Santamaria, A.; Wudka, J. url  doi
openurl 
  Title Effective Lagrangian approach to neutrinoless double beta decay and neutrino masses Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 06 Issue 6 Pages 146 - 37pp  
  Keywords Beyond Standard Model; Neutrino Physics  
  Abstract (down) Neutrinoless double beta (0 nu beta beta) decay can in general produce electrons of either chirality, in contrast with the minimal Standard Model (SM) extension with only the addition of the Weinberg operator, which predicts two left-handed electrons in the final state. We classify the lepton number violating (LNV) effective operators with two leptons of either chirality but no quarks, ordered according to the magnitude of their contribution to 0 nu beta beta decay. We point out that, for each of the three chirality assignments, e(L)e(L), e(L)e(R) and e(R)e(R), there is only one LNV operator of the corresponding type to lowest order, and these have dimensions 5, 7 and 9, respectively. Neutrino masses are always induced by these extra operators but can be delayed to one or two loops, depending on the number of RH leptons entering in the operator. Then, the comparison of the 0 nu beta beta decay rate and neutrino masses should indicate the effective scenario at work, which confronted with the LHC searches should also eventually decide on the specific model elected by nature. We also list the SM additions generating these operators upon integration of the heavy modes, and discuss simple realistic examples of renormalizable theories for each case.  
  Address [del Aguila, Franciso] 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  
  Notes WOS:000306418300055 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1177  
Permanent link to this record
 

 
Author Li, X.Q.; Li, Y.M.; Lu, G.R.; Su, F. url  doi
openurl 
  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 (down) 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  
  Notes WOS:000305236000049 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1103  
Permanent link to this record
 

 
Author Bloch, I.M.; Caputo, A.; Essig, R.; Redigolo, D.; Sholapurkar, M.; Volansky, T. url  doi
openurl 
  Title Exploring new physics with O(keV) electron recoils in direct detection experiments Type Journal Article
  Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 01 Issue 1 Pages 178 - 63pp  
  Keywords Beyond Standard Model; Cosmology of Theories beyond the SM  
  Abstract (down) Motivated by the recent XENON1T results, we explore various new physics models that can be discovered through searches for electron recoils in O(keV)-threshold direct-detection experiments. First, we consider the absorption of axion-like particles, dark photons, and scalars, either as dark matter relics or being produced directly in the Sun. In the latter case, we find that keV mass bosons produced in the Sun provide an adequate fit to the data but are excluded by stellar cooling constraints. We address this tension by introducing a novel Chameleon-like axion model, which can explain the excess while evading the stellar bounds. We find that absorption of bosonic dark matter provides a viable explanation for the excess only if the dark matter is a dark photon or an axion. In the latter case, photophobic axion couplings are necessary to avoid X-ray constraints. Second, we analyze models of dark matter-electron scattering to determine which models might explain the excess. Standard scattering of dark matter with electrons is generically in conflict with data from lower-threshold experiments. Momentum-dependent interactions with a heavy mediator can fit the data with dark matter mass heavier than a GeV but are generically in tension with collider constraints. Next, we consider dark matter consisting of two (or more) states that have a small mass splitting. The exothermic (down)scattering of the heavier state to the lighter state can fit the data for keV mass splittings. Finally, we consider a subcomponent of dark matter that is accelerated by scattering off cosmic rays, finding that dark matter interacting though an O(100 keV)-mass mediator can fit the data. The cross sections required in this scenario are, however, typically challenged by complementary probes of the light mediator. Throughout our study, we implement an unbinned Monte Carlo analysis and use an improved energy reconstruction of the XENON1T events.  
  Address [Bloch, Itay M.; Volansky, Tomer] Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel, Email: itay.bloch.m@gmail.com;  
  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:000616257000001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4713  
Permanent link to this record
 

 
Author Chang, Q.; Li, X.Q.; Yang, Y.D. url  doi
openurl 
  Title 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 (down) 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 Hirsch, M.; Joaquim, F.R.; Vicente, A. url  doi
openurl 
  Title Constrained SUSY seesaws with a 125 GeV Higgs Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 11 Issue 11 Pages 105 - 33pp  
  Keywords Higgs Physics; Rare Decays; Neutrino Physics; Supersymmetric Standard Model  
  Abstract (down) Motivated by the ATLAS and CMS discovery of a Higgs-like boson with a mass around 125 GeV, and by the need of explaining neutrino masses, we analyse the three canonical SUSY versions of the seesaw mechanism (type I, II and III) with CMSSM boundary conditions. In type II and III cases, SUSY particles are lighter than in the CMSSM (or the constrained type I seesaw), for the same set of input parameters at the universality scale. Thus, to explain m(h0) similar or equal to 125 GeV at low energies, one is forced into regions of parameter space with very large values of m(0), M-1/2 or A(0). We compare the squark and gluino masses allowed by the ATLAS and CMS ranges for m(h0) (extracted from the 2011-2012 data), and discuss the possibility of distinguishing seesaw models in view of future results on SUSY searches. In particular, we briefly comment on the discovery potential of LHC upgrades, for squark/gluino mass ranges required by present Higgs mass constraints. A discrimination between different seesaw models cannot rely on the Higgs mass data alone, therefore we also take into account the MEG upper limit on BR(mu -> e gamma) and show that, in some cases, this may help to restrict the SUSY parameter space, as well as to set complementary limits on the seesaw scale.  
  Address [Hirsch, M.] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, E-46071 Valencia, Spain, Email: mahirsch@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 WOS:000312198500040 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1301  
Permanent link to this record
 

 
Author de Medeiros Varzielas, I.; King, S.F.; Luhn, C.; Neder, T. url  doi
openurl 
  Title Spontaneous CP violation in multi-Higgs potentials with triplets of Delta(3n(2)) and Delta(6n(2)) Type Journal Article
  Year 2017 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 11 Issue 11 Pages 136 - 56pp  
  Keywords CP violation; Discrete Symmetries; Higgs Physics; Beyond Standard Model  
  Abstract (down) Motivated by discrete flavour symmetry models, we analyse Spontaneous CP Violation (SCPV) for potentials involving three or six Higgs fi elds (both electroweak doublets and singlets) which fall into irreducible triplet representations of discrete symmetries belonging to the Delta(3n(2)) and Delta(6n(2)) series, including A(4), S-4, Delta(27) and Delta(54). For each case, we give the potential and fi nd various global minima for di ff erent regions of the parameter space of the potential. Using CP-odd basis Invariants that indicate the presence of Spontaneous CP Violation we separate the VEVs into those that do or do not violate CP. In cases where CP is preserved we reveal a CP symmetry of the potential that is preserved by those VEVs, otherwise we display a non-zero CP-odd Invariant. Finally we identify interesting cases where there is Spontaneous Geometrical CP Violation in which the VEVs have geometrical phases.  
  Address [Varzielas, Ivo de Medeiros; King, Stephen F.; Neder, Thomas] Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England, Email: ivo.de@udo.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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000416354700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 3383  
Permanent link to this record
 

 
Author Fonseca, R.M.; Hirsch, M. url  doi
openurl 
  Title A flipped 331 model Type Journal Article
  Year 2016 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 08 Issue 8 Pages 003 - 12pp  
  Keywords Beyond Standard Model; Gauge Symmetry; Neutrino Physics  
  Abstract (down) Models based on the extended SU(3)(C) x SU(3)(L) x U(1)(X) (331) gauge group usually follow a common pattern: two families of left-handed quarks are placed in anti triplet representations of the SU(3)(L) group; the remaining quark family, as well as the left-handed leptons, are assigned to triplets (or vice-versa). In this work we present a flipped 331 model where this scheme is reversed: all three quark families are in the same representation and it is the lepton families which are discriminated by the gauge symmetry. We discuss fermion masses and mixing, as well as Z' interactions, in a minimal model implementing this idea.  
  Address [Fonseca, Renato M.; Hirsch, Martin] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Parc Cient Paterna,Calle Jose Beltran, E-46980 Paterna, Valencia, Spain, Email: renato.fonseca@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:000381218300003 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 2782  
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Author ATLAS Collaboration (Aad, G. et al); Aparisi Pozo, J.A.; Bailey, A.J.; Cabrera Urban, S.; Cardillo, F.; Castillo, F.L.; Castillo Gimenez, V.; Costa, M.J.; Escobar, C.; Estrada Pastor, O.; Ferrer, A.; Fiorini, L.; Fullana Torregrosa, E.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Gonzalvo Rodriguez, G.R.; Guerrero Rojas, J.G.R.; Higon-Rodriguez, E.; Lacasta, C.; Lozano Bahilo, J.J.; Mamuzic, J.; Marti-Garcia, S.; Martinez Agullo, P.; Mitsou, V.A.; Moreno Llacer, M.; Poveda, J.; Prades Ibañez, A.; Rodriguez Bosca, S.; Ruiz-Martinez, A.; Sabatini, P.; Salt, J.; Santra, A.; Sayago Galvan, I.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valero, A.; Valls Ferrer, J.A.; Villaplana Perez, M.; Vos, M. url  doi
openurl 
  Title Measurements of differential cross-sections in four-lepton events in 13 TeV proton-proton collisions with the ATLAS detector Type Journal Article
  Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 005 - 67pp  
  Keywords Hadron-Hadron scattering (experiments); Lepton production; proton-proton scattering; Beyond Standard Model; Branching fraction  
  Abstract (down) Measurements of four-lepton differential and integrated fiducial cross-sections in events with two same-flavour, opposite-charge electron or muon pairs are presented. The data correspond to 139 fb(-1) of root s = 13 TeV proton-proton collisions, collected by the ATLAS detector during Run 2 of the Large Hadron Collider (2015-2018). The final state has contributions from a number of interesting Standard Model processes that dominate in different four-lepton invariant mass regions, including single Z boson production, Higgs boson production and on-shell ZZ production, with a complex mix of interference terms, and possible contributions from physics beyond the Standard Model. The differential cross-sections include the four-lepton invariant mass inclusively, in slices of other kinematic variables, and in different lepton flavour categories. Also measured are dilepton invariant masses, transverse momenta, and angular correlation variables, in four regions of four-lepton invariant mass, each dominated by different processes. The measurements are corrected for detector effects and are compared with state-of-the-art Standard Model calculations, which are found to be consistent with the data. The Z -> 4l branching fraction is extracted, giving a value of (4.41 +/- 0.30) x 10(-6). Constraints on effective field theory parameters and a model based on a spontaneously broken B – L gauge symmetry are also evaluated. Further reinterpretations can be performed with the provided information.  
  Address [Duvnjak, D.; Jackson, P.; Kong, A. X. Y.; Oliver, J. L.; Ruggeri, T. A.; Sharma, A. S.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia  
  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:000671563800001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4891  
Permanent link to this record
 

 
Author Bernabeu, J.; Segarra, A. url  doi
openurl 
  Title Stimulated transitions in resonant atom Majorana mixing Type Journal Article
  Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 02 Issue 2 Pages 017 - 16pp  
  Keywords Neutrino Physics; Beyond Standard Model; Global Symmetries  
  Abstract (down) Massive neutrinos demand to ask whether they are Dirac or Majorana particles. Majorana neutrinos are an irrefutable proof of physics beyond the Standard Model. Neutrinoless double electron capture is not a process but a virtual Delta L = 2 mixing between a parent (A)Z atom and a daughter (A)(Z – 2) excited atom with two electron holes. As a mixing between two neutral atoms and the observable signal in terms of emitted two-hole X-rays, the strategy, experimental signature and background are different from neutrinoless double beta decay. The mixing is resonantly enhanced for almost degeneracy and, under these conditions, there is no irreducible background from the standard two-neutrino channel. We reconstruct the natural time history of a nominally stable parent atom since its production either by nature or in the laboratory. After the time periods of atom oscillations and the decay of the short-lived daughter atom, at observable times the relevant 'stationary" states are the mixed metastable long-lived state and the non-orthogonal short-lived excited state, as well as the ground state of the daughter atom. We find that they have a natural population inversion which is most appropriate for exploiting the bosonic nature of the observed atomic transitions radiation. Among different observables of the atom Majorana mixing, we include the enhanced rate of stimulated X-ray emission from the long-lived metastable state by a high-intensity X-ray beam: a gain factor of 100 can be envisaged at current XFEL facilities. On the other hand, the historical population of the daughter atom ground state can be probed by exciting it with a current pulsed optical laser, showing the characteristic absorption lines: the whole population can be excited in a shorter time than typical pulse duration.  
  Address [Bernabeu, Jose] Univ Valencia, CSIC, Dept Fis Teor, Calle Dr Moliner 50, E-46100 Burjassot, Spain, Email: Jose.Bernabeu@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:000424101600008 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 3475  
Permanent link to this record
 

 
Author Escribano, P.; Vicente, A. url  doi
openurl 
  Title Ultralight scalars in leptonic observables Type Journal Article
  Year 2021 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 03 Issue 3 Pages 240 - 37pp  
  Keywords Beyond Standard Model; CP violation; Neutrino Physics  
  Abstract (down) Many new physics scenarios contain ultralight scalars, states which are either exactly massless or much lighter than any other massive particle in the model. Axions and majorons constitute well-motivated examples of this type of particle. In this work, we explore the phenomenology of these states in low-energy leptonic observables. After adopting a model independent approach that includes both scalar and pseudoscalar interactions, we briefly discuss the current limits on the diagonal couplings to charged leptons and consider processes in which the ultralight scalar phi is directly produced, such as μ-> e phi, or acts as a mediator, as in tau -> μμmu. Contributions to the charged leptons magnetic and electric moments are studied as well.  
  Address [Escribano, Pablo; Vicente, Avelino] Univ Valencia, CSIC, Inst Fis Corpuscular, C Catedrat Jose Beltran 2, E-46980 Valencia, Spain, Email: pablo.escribano@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:000635264700005 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 4769  
Permanent link to this record
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