| |
Records |
Links |
|
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 |
|
|
| |
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 |
|
| Permanent link to this record |
| |
|
| |
|
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 |
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 |
|
| Permanent link to this record |
| |
|
| |
|
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 |
|
|
| |
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 |
|
| Permanent link to this record |
| |
|
| |
|
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 |
|
|
| |
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 |
Cepedello, R.; Fonseca, R.M.; Hirsch, M. |
|
| |
Title |
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 |
