| Records |
| 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 |
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| 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 |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2470-0010 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000439791500005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
3675 |
| Permanent link to this record |
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| Author |
Fonseca, R.M.; Hirsch, M. |
| Title |
SU(5)-inspired double beta decay |
Type |
Journal Article |
| Year |
2015 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
92 |
Issue |
1 |
Pages |
015014 - 14pp |
| Keywords |
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| Abstract |
The short-range part of the neutrinoless double beta amplitude is generated via the exchange of exotic particles, such as charged scalars, leptoquarks and/or diquarks. In order to give a sizable contribution to the total decay rate, the masses of these exotics should be of the order of (at most) a few TeV. Here, we argue that these exotics could be the “light” (i.e., weak-scale) remnants of some B – L violating variants of SU(5). We show that unification of the standard model gauge couplings, consistent with proton decay limits, can be achieved in such a setup without the need to introduce supersymmetry. Since these nonminimal SU(5)-inspired models violate B – L, they generate Majorana neutrino masses and therefore make it possible to explain neutrino oscillation data. The light colored particles of these models can potentially be observed at the LHC, and it might be possible to probe the origin of the neutrino masses with Delta L = 2 violating signals. As particular realizations of this idea, we present two models, one for each of the two possible tree-level topologies of neutrinoless double beta decay. |
| Address |
[Fonseca, Renato M.; Hirsch, Martin] Univ Valencia, AHEP Grp, CSIC, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: renato.fonseca@ific.uv.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1550-7998 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000357860200006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
2300 |
| Permanent link to this record |
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| Author |
Arbelaez, C.; Gonzalez, M.; Kovalenko, S.G.; Hirsch, M. |
| Title |
QCD-improved limits from neutrinoless double beta decay |
Type |
Journal Article |
| Year |
2017 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
96 |
Issue |
1 |
Pages |
015010 - 12pp |
| Keywords |
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| Abstract |
We analyze the impact of QCD corrections on limits derived from neutrinoless double beta decay (0 nu beta beta ). As demonstrated previously, the effect of the color mismatch arising from loops with gluons linking the quarks from different color-singlet currents participating in the effective operators has a dramatic impact on the predictions for some particular Wilson coefficients. Here, we consider all possible contributions from heavy particle exchange, i.e. the so-called short-range mechanism of 0 nu beta beta decay. All high-scale models (HSM) in this class match at some scale around a similar to few TeV with the corresponding effective theory, containing a certain set of effective dimension-9 operators. Many of these HSM receive contributions from more than one of the basic operators and we calculate limits on these models using the latest experimental data. We also show with one nontrivial example, how to derive limits on more complicated models, in which many different Feynman diagrams contribute to 0 nu beta beta decay, using our general method. |
| Address |
[Arbelaez, C.; Gonzalez, M.; Kovalenko, S. G.] Univ Tecn Federico Santa Maria, Ctr Cient Tecnol Valparaiso, Casilla 110-5, Valparaiso, Chile, Email: carolina.arbelaez@usm.cl; |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2470-0010 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000405188200006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
3198 |
| Permanent link to this record |
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| Author |
Gonzalez, M.; Kovalenko, S.G.; Hirsch, M. |
| Title |
QCD running in neutrinoless double beta decay: Short-range mechanisms |
Type |
Journal Article |
| Year |
2016 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
93 |
Issue |
1 |
Pages |
013017 - 11pp |
| Keywords |
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| Abstract |
The decay rate of neutrinoless double beta (0 nu beta beta) decay contains terms from heavy particle exchange, which lead to dimension-9 (d = 9) six fermion operators at low energies. Limits on the coefficients of these operators have been derived previously neglecting the running of the operators between the high scale, where they are generated, and the energy scale of 0 nu beta beta decay, where they are measured. Here we calculate the leading-order QCD corrections to all possible d = 9 operators contributing to the 0 nu beta beta amplitude and use renormalization group running to calculate 1-loop improved limits. Numerically, QCD running dramatically changes some limits by factors of the order of or larger than typical uncertainties in nuclear matrix element calculations. For some specific cases, operator mixing in the running changes limits even by up to 3 orders of magnitude. Our results can be straightforwardly combined with new experimental limits or improved nuclear matrix element calculations to rederive updated limits on all short-range contributions to 0 nu beta beta decay. |
| Address |
[Gonzalez, M.; Kovalenko, S. G.] Univ Tecn Federico Santa Maria, Ctr Cient Tecnol Valparaiso, Casilla 110-V, Valparaiso 2390123, Chile, Email: marcela.gonzalezp@titulados.usm.cl; |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1550-7998 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000368516100002 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
2539 |
| Permanent link to this record |
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| Author |
Hirsch, M.; Porod, W.; Weiss, C.; Staub, F. |
| Title |
Supersymmetric type-III seesaw mechanism: Lepton flavor violation and LHC phenomenology |
Type |
Journal Article |
| Year |
2013 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
87 |
Issue |
1 |
Pages |
013010 - 12pp |
| Keywords |
|
| Abstract |
We study a supersymmetric version of the type-III seesaw mechanism considering two variants of the model: a minimal version for explaining neutrino data with only two copies of 24 superfields and a model with three generations of 24-plets. The latter predicts, in general, rates for μ-> e gamma inconsistent with experimental data. However, this bound can be evaded if certain special conditions within the neutrino sector are fulfilled. In the case of two 24-plets, lepton flavor violation constraints can be satisfied much more easily. After specifying the corresponding regions in the minimal supergravity parameter space, we show that under favorable conditions one can test the corresponding flavor structures in the leptonic sector at the LHC. For this we perform Monte Carlo studies for the signals, also taking into account the supersymmetry background. We find that it is only of minor importance for the scenarios studied here. |
| Address |
[Hirsch, M.] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, E-46071 Valencia, Spain, Email: mahirsch@ific.uv.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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| Language |
English |
Summary Language |
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Original Title |
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| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1550-7998 |
ISBN |
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Medium |
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| Area |
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Expedition |
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Conference |
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| Notes |
WOS:000313945700001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
1310 |
| Permanent link to this record |
