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Author Barenboim, G.; Rasero, J.
Title Electroweak baryogenesis window in non standard cosmologies Type Journal Article
Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 07 Issue 7 Pages 028 - 20pp
Keywords Cosmology of Theories beyond the SM; Beyond Standard Model; Neutrino Physics
Abstract (up) In this work we show that the new bounds on the Higgs mass are more than difficult to reconcile with the strong constraints on the physical parameters of the Standard Model and the Minimal Supersymmetric Standard Model imposed by the preservation of the baryon asymmetry. This bound can be weakened by assuming a nonstandard cosmology at the time of the electroweak phase transition, reverting back to standard cosmology by BBN time. Two explicit examples are an early period of matter dominated expansion due to a heavy right handed neutrino (see-saw scale), or a nonstandard braneworld expansion.
Address [Barenboim, Gabriela] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: gabriela.barenboim@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:000307298400028 Approved no
Is ISI yes International Collaboration
Call Number IFIC @ pastor @ Serial 1158
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Author Beltran, R.; Cottin, G.; Helo, J.C.; Hirsch, M.; Titov, A.; Wang, Z.S.
Title Long-lived heavy neutral leptons at the LHC: four-fermion single-N-R operators Type Journal Article
Year 2022 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 01 Issue 1 Pages 044 - 18pp
Keywords Beyond Standard Model; Effective Field Theories; Neutrino Physics
Abstract (up) Interest in searches for heavy neutral leptons (HNLs) at the LHC has increased considerably in the past few years. In the minimal scenario, HNLs are produced and decay via their mixing with active neutrinos in the Standard Model (SM) spectrum. However, many SM extensions with HNLs have been discussed in the literature, which sometimes change expectations for LHC sensitivities drastically. In the N-R SMEFT, one extends the SM effective field theory with operators including SM singlet fermions, which allows to study HNL phenomenology in a “model independent” way. In this paper, we study the sensitivity of ATLAS to HNLs in the N-R SMEFT for four-fermion operators with a single HNL. These operators might dominate both production and decay of HNLs, and we find that new physics scales in excess of 20 TeV could be probed at the high-luminosity LHC.
Address [Beltran, Rebeca; Hirsch, Martin] Univ Valencia, AHEP Grp, Inst Fis Corpuscular, CSIC, Apartado 22085, E-46071 Valencia, Spain, Email: rebeca.beltran@ifis.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:000742012500001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5079
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Author Anamiati, G.; Hirsch, M.; Nardi, E.
Title Quasi-Dirac neutrinos at the LHC Type Journal Article
Year 2016 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 010 - 19pp
Keywords Beyond Standard Model; Neutrino Physics
Abstract (up) Lepton number violation is searched for at the LHC using same-sign leptons plus jets. The standard lore is that the ratio of same-sign lepton to opposite-sign lepton events, R-ll, is equal to R-ll = 1 (R-ll = 0) for Majorana (Dirac) neutrinos. We clarify under which conditions the ratio Rll can assume values different from 0 and 1, and we argue that the precise value 0 < R-ll < 1 is controlled by the mass splitting versus the width of the quasi-Dirac resonances. A measurement of R-ll not equal 0, 1 would then contain valuable information about the origin of neutrino masses. We consider as an example the inverse seesaw mechanism in a left-right symmetric scenario, which is phenomenologically particularly interesting since all the heavy states in the high energy completion of the model could be within experimental reach. A prediction of this scenario is a correlation between the values of R-ll and the ratio between the rates for heavy neutrino decays into standard model gauge bosons, and into three body final states ljj mediated by off-shell W-R exchange.
Address [Anamiati, G.; Hirsch, M.] Univ Valencia, AHEP Grp, CSIC, Inst Fis Corpuscular, Edificio Inst Invest,Parc Cient Paterna, E-46071 Valencia, Spain, Email: anamiati@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:000385397800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2834
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Author Helo, J.C.; Hirsch, M.; Wang, Z.S.
Title Heavy neutral fermions at the high-luminosity LHC Type Journal Article
Year 2018 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 07 Issue 7 Pages 056 - 23pp
Keywords Beyond Standard Model; Neutrino Physics; Supersymmetric Standard Model
Abstract (up) Long-lived light particles (LLLPs) appear in many extensions of the standard model. LLLPs are usually motivated by the observed small neutrino masses, by dark matter or both. Typical examples for fermionic LLLPs (a.k.a. heavy neutral fermions, HNFs) are sterile neutrinos or the lightest neutralino in R-parity violating supersymmetry. The high luminosity LHC is expected to deliver up to 3/ab of data. Searches for LLLPs in dedicated experiments at the LHC could then probe the parameter space of LLLP models with unprecedented sensitivity. Here, we compare the prospects of several recent experimental proposals, FASER, CODEX-b and MATHUSLA, to search for HNFs and discuss their relative merits.s
Address [Helo, Juan Carlos] Univ La Serena, Fac Ciencias, Dept Fis, Ave Cisternas 1200, La Serena, Chile, Email: jchelo@userena.cl;
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:000438141500008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3656
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Author Arguelles, C.A.; Coloma, P.; Hernandez, P.; Muñoz, V.
Title Searches for atmospheric long-lived particles Type Journal Article
Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages 190 - 34pp
Keywords Beyond Standard Model; Neutrino Physics; Solar and Atmospheric Neutrinos
Abstract (up) Long-lived particles are predicted in extensions of the Standard Model that involve relatively light but very weakly interacting sectors. In this paper we consider the possibility that some of these particles are produced in atmospheric cosmic ray showers, and their decay intercepted by neutrino detectors such as IceCube or Super-Kamiokande. We present the methodology and evaluate the sensitivity of these searches in various scenarios, including extensions with heavy neutral leptons in models of massive neutrinos, models with an extra U(1) gauge symmetry, and a combination of both in a U(1)(B-L) model. Our results are shown as a function of the production rate and the lifetime of the corresponding long-lived particles.
Address [Arguelles, C.] MIT, Dept Phys, Cambridge, MA 02139 USA, Email: caad@mit.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:000518622800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4323
Permanent link to this record