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Author Gonzalez, M.; Hirsch, M.; Kovalenko, S.G.
Title Neutrinoless double beta decay and QCD running at low energy scales Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 97 Issue 11 Pages 115005 - 6pp
Keywords (up)
Abstract There is a common belief that the main uncertainties in the theoretical analysis of neutrinoless double beta (0 nu beta beta) decay originate from the nuclear matrix elements. Here, we uncover another previously overlooked source of potentially large uncertainties stemming from nonperturbative QCD effects. Recently perturbative QCD corrections have been calculated for all dimension 6 and 9 effective operators describing 0 nu beta beta-decay and their importance for a reliable treatment of 0 nu beta beta-decay has been demonstrated. However, these perturbative results are valid at energy scales above similar to 1 GeV, while the typical 0 nu beta beta scale is about similar to 100 MeV. In view of this fact we examine the possibility of extrapolating the perturbative results towards sub-GeV nonperturbative scales on the basis of the QCD coupling constant “freezing” behavior using background perturbation theory. Our analysis suggests that such an infrared extrapolation does modify the perturbative results for both short-range and long-range mechanisms of 0 nu beta beta-decay in general only moderately. We also discuss that the tensor circle times tensor effective operator cannot appear alone in the low energy limit of any renormalizable high-scale model and then demonstrate that all five linearly independent combinations of the scalar and tensor operators, which can appear in renormalizable models, are infrared stable.
Address [Gonzalez, M.; Kovalenko, S. G.] Univ Tecn Federico Santa Maria, Ctr Cient Tecnol Valparaiso, Casilla 110-V, Valparaiso 2390123, Chile, Email: marcela.gonzalezp@usm.cl;
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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000434211200008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3603
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Author Hirsch, M.; Srivastava, R.; Valle, J.W.F.
Title Can one ever prove that neutrinos are Dirac particles? Type Journal Article
Year 2018 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 781 Issue Pages 302-305
Keywords (up)
Abstract According to the “Black Box” theorem the experimental confirmation of neutrinoless double beta decay (0 nu 2 beta) would imply that at least one of the neutrinos is a Majorana particle. However, a null 0 nu 2 beta signal cannot decide the nature of neutrinos, as it can be suppressed even for Majorana neutrinos. In this letter we argue that if the null 0 nu 2 beta decay signal is accompanied by a 0 nu 2 beta quadruple beta decay signal, then at least one neutrino should be a Dirac particle. This argument holds irrespective of the underlying processes leading to such decays.
Address [Hirsch, Martin; Srivastava, Rahul; Valle, Jose W. F.] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, C Catedrat Jose Beltran 2, E-46980 Valencia, Spain, Email: mahirsch@ific.uv.es;
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 WOS:000435653100039 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3632
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Author Fonseca, R.M.; Hirsch, M.
Title Delta L >= 4 lepton number violating processes Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 1 Pages 015035 - 12pp
Keywords (up)
Abstract We discuss the experimental prospects for observing processes which violate lepton number (Delta L) in four units ( or more). First, we reconsider neutrinoless quadruple beta decay, deriving a model independent and very conservative lower limit on its half- life of the order of 10(41) ys for Nd-150. This renders quadruple beta decay unobservable for any feasible experiment. We then turn to a more general discussion of different possible low-energy processes with values Delta L >= 4. A simple operator analysis leads to rather pessimistic conclusions about the observability at low-energy experiments in all cases we study. However, the situation looks much brighter for accelerator experiments. For two example models with Delta L = 4 and another one with Delta L = 5, we show how the LHC or a hypothetical future pp collider, such as the FCC, could probe multilepton number violating operators at the TeV scale.
Address [Fonseca, Renato M.; Hirsch, Martin] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Spain Edificio Inst Paterna,Apartado 22085, E-46071 Valencia, Spain, Email: renato.fonseca@ific.uv.es;
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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000439791500005 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3675
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Author Cottin, G.; Helo, J.C.; Hirsch, M.
Title Displaced vertices as probes of sterile neutrino mixing at the LHC Type Journal Article
Year 2018 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 98 Issue 3 Pages 035012 - 6pp
Keywords (up)
Abstract We investigate the reach at the LHC to probe light sterile neutrinos with displaced vertices. We focus on sterile neutrinos N with masses m(N) similar to (5-30) GeV that are produced in rare decays of the standard model gauge bosons and decay inside the inner trackers of the LHC detectors. With a strategy that triggers on the prompt lepton accompanying the N displaced vertex and considers charged tracks associated with it, we show that the 13 TeV LHC with 3000/fb is able to probe active-sterile neutrino mixings down to vertical bar V-lN vertical bar(2) approximate to 10(-9), with l = e, mu, which is an improvement of up to 4 orders of magnitude when comparing with current experimental limits from trileptons and proposed lepton-jets searches. In the case when tau mixing is present, mixing angles as low as vertical bar V-tau N vertical bar(2) approximate to 10(-8) can be accessed.
Address [Cottin, Giovanna] Natl Taiwan Univ, Dept Phys, Taipei 10617, Taiwan, Email: gcottin@phys.ntu.edu.tw;
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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000441109800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3684
Permanent link to this record
 

 
Author Dercks, D.; Dreiner, H.K.; Hirsch, M.; Wang, Z.S.
Title Long-lived fermions at AL3X Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 5 Pages 055020 - 10pp
Keywords (up)
Abstract Recently Gligorov et al. [V. V. Gligorov et al., Phys. Rev. D 99, 015023 (2019)] proposed to build a cylindrical detector named AL3X close to the ALICE experiment at interaction point (IP) 2 of the LHC, aiming for discovery of long-lived particles (LLPs) during Run 5 of the HL-LHC. We investigate the potential sensitivity reach of this detector in the parameter space of different new-physics models with long-lived fermions namely heavy neutral leptons (HNLs) and light supersymmetric neutralinos, which have both not previously been studied in this context. Our results show that the AL3X reach can be complementary or superior to that of other proposed detectors such as CODEX-b, FASER, MATHUSLA and SHiP.
Address [Dercks, Daniel] DESY, Notkestr 85, D-22607 Hamburg, Germany, Email: daniel.dercks@desy.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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000461906400007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3949
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Author Cordero-Carrion, I.; Hirsch, M.; Vicente, A.
Title Master Majorana neutrino mass parametrization Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 7 Pages 075019 - 6pp
Keywords (up)
Abstract After introducing a master formula for the Majorana neutrino mass matrix, we present a master parametrization for the Yukawa matrices automatically in agreement with neutrino oscillation data. This parametrization can be used for any model that induces Majorana neutrino masses. The application of the master parametrization is also illustrated in an example model, with special focus on its lepton flavor violating phenomenology.
Address [Cordero-Carrion, I.] Univ Valencia, Dept Matemat, E-46100 Valencia, Spain, Email: isabel.cordero@uv.es;
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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000464743100007 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 3981
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Author Cepedello, R.; Deppisch, F.F.; Gonzalez, L.; Hati, C.; Hirsch, M.
Title Neutrinoless Double-Beta Decay with Nonstandard Majoron Emission Type Journal Article
Year 2019 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 122 Issue 18 Pages 181801 - 6pp
Keywords (up)
Abstract We present a novel mode of neutrinoless double-beta decay with emission of a light Majoron-like scalar particle phi. We assume it couples via an effective seven-dimensional operator with a (V + A) lepton current and (V +/- A) quark currents leading to a long-range contribution that is unsuppressed by the light neutrino mass. We calculate the total double-beta decay rate and determine the fully differential shape for this mode. We find that future double-beta decay searches are sensitive to scales of the order Lambda(NP) approximate to 1 TeV for the effective operator and a light scalar m(phi) < 0.2 MeV, based on ordinary double-beta decay Majoron searches. The angular and energy distributions can deviate considerably from that of two-neutrino double-beta decay, which is the main background. We point out possible ultraviolet completions where such an effective operator can emerge.
Address [Cepedello, Ricardo; Hirsch, Martin] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Edificio Inst Paterna,Apartado 22085, E-46071 Valencia, Spain, Email: ricepe@ific.uv.es;
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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000467042800001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4002
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Author Helo, J.C.; Hirsch, M.; Ota, T.
Title Proton decay at one loop Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 9 Pages 095021 - 14pp
Keywords (up)
Abstract Proton decay is usually discussed in the context of grand unified theories. However, as is well known, in the standard model effective theory proton decay appears in the form of higher-dimensional non-renormalizable operators. Here, we study systematically the one-loop decomposition of the d = 6 B + L violating operators. We exhaustively list the possible one-loop ultraviolet completions of these operators and discuss that, in general, two distinct classes of models appear. Models in the first class need an additional symmetry in order to avoid tree-level proton decay. These models necessarily contain a neutral particle, which could act as a dark matter candidate. For models in the second class the loop contribution dominates automatically over the tree-level proton decay, without the need for additional symmetries. We also discuss possible phenomenology of two example models, one from each class, and their possible connections to neutrino masses, LHC searches and dark matter.
Address [Helo, Juan Carlos] Univ La Serena, Dept Fis, Fac Ciencias, Ave Cisternas 1200, La Serena 1200, Chile, Email: jchelo@userena.cl;
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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000469019900005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4035
Permanent link to this record
 

 
Author Cottin, G.; Helo, J.C.; Hirsch, M.; Silva, D.
Title Revisiting the LHC reach in the displaced region of the minimal left-right symmetric model Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 11 Pages 115013 - 4pp
Keywords (up)
Abstract We revisit discovery prospects for a long-lived sterile neutrino N at the LHC in the context of left-right symmetric theories. We focus on a displaced vertex search strategy sensitive to O(GeV) neutrino masses produced via a right-handed W-R boson. Both on-shell and off-shell Drell-Yan production of W-R are considered. We estimate the reach as a function of m(N) and m(WR). With root s = 13 TeV and 300/fb of integrated luminosity, the LHC can probe neutrino masses as high as approximately 30 GeV and m(wR) around 6 TeV. The reach goes up to 11.5 TeV with 3000/tb and m(N) similar to 45 GeV. This represents an improvement of a factor of 2 in sensitivity with respect to earlier work.
Address [Cottin, Giovanna] Natl Taiwan Univ, Dept Phys, Taipei 10617, Taiwan, Email: gcottin@phys.ntu.edu.tw
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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000470867500008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4055
Permanent link to this record
 

 
Author Carquin, E.; Neill, N.A.; Helo, J.C.; Hirsch, M.
Title Exotic colored fermions and lepton number violation at the LHC Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 11 Pages 115028 - 9pp
Keywords (up)
Abstract Majorana neutrino mass models with a scale of lepton number violation of order tem-electron-volts potentially lead to signals at the LHC. Here, we consider an extension of the standard model with a colored octet fermion and a scalar leptoquark. This model generates neutrino masses at two-loop order. We make a detailed Monte Carlo study of the lepton number violating signal at the LHC in this model, including a simulation of standard model backgrounds. Our forecast predicts that the LHC with 300/fb should be able to probe this model up to color-octet fermion masses in the range of (2.6-2.7) TeV, depending on the lepton flavor of the final state.
Address [Carquin, E.; Neill, N. A.] Univ Tecn Federico Santa Maria, Dept Fis, Casilla 110-V, Valparaiso, Chile, Email: edson.carquin@usm.cl;
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 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000473024800004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4068
Permanent link to this record