| Records |
| Author |
Helo, J.C.; Ota, T.; Hirsch, M. |
| Title |
Invisible neutron decay and light BSM particles |
Type |
Journal Article |
Year  |
2026 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
113 |
Issue |
3 |
Pages |
035002 - 17pp |
| Keywords |
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| Abstract |
In Standard Model (SM) effective field theory, invisible neutron decay arises from d = 12 operators. Adding new, light particles to the field content of the SM, such as right-handed neutrinos, allows to construct operators for invisible neutron decay at much lower dimensions. Observing invisible neutron decay, if nucleon decays with charged leptons remain absent, would therefore point towards the existence of new neutral degrees of freedom. Here, we discuss four cases: (i) Adding right-handed neutrinos to the SM; (ii) a right-handed neutrino and an axionlike particle; (iii) a right-handed neutrino and a (nearly) massless singlet scalar; and (iv) a right-handed neutrino and a light Z'. We give the general tree-level decomposition for the resulting d = (7-9) operators for invisible neutron decay. We also briefly discuss LHC searches related to the exotic states found in these UV completions. |
| Address |
[Helo, J. C.; Ota, T.] Univ La Serena, Fac Ciencias, Dept Fis, Ave Cisternas 1200, La Serena, Chile, Email: jchelo@userena.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:001686375800002 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
7053 |
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| Author |
Beltran, R.; Hati, C.; Hirsch, M.; Martin-Galan, A. |
| Title |
Long-lived HNLs via ALP portal at the LHC |
Type |
Journal Article |
| Year |
2026 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
03 |
Issue |
3 |
Pages |
233 - 23pp |
| Keywords |
Axions and ALPs; Sterile or Heavy Neutrinos |
| Abstract |
Heavy neutral leptons (HNLs) and axion-like particles (ALPs) are both considered well-motivated candidates for beyond the standard model (BSM) physics. If ALPs with sizable couplings to gluons exist, they will be abundantly produced at the LHC. Therefore, HNLs produced via the ALP portal may provide unprecedented sensitivities to HNL parameters. Here, we study the prospects for the high-luminosity LHC to search for long-lived HNLs. We consider future far detectors as well as ATLAS in our simulations. In the limit where the ALP mass is above the TeV scale, HNLs are effectively produced by a dimension-8 operator connecting HNL pairs to gluons. For completeness, we therefore also calculate future LHC sensitivities for HNLs produced via NRSMEFT operators with gluons. |
| Address |
[Beltran, Rebeca; Hati, Chandan; Hirsch, Martin; Martin-Galan, Ana] Univ Valencia, Inst Fis Corpuscular, CSIC, C-Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: beltran-lloria.rebeca@ucy.ac.cy; |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
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 |
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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:001723877400010 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
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| Call Number |
IFIC @ pastor @ |
Serial |
7157 |
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| Author |
Donini, A.; Gonzalez, M.; Hirsch, M.; Neill, N.A. |
| Title |
Leading large Nc contributions to lepton number violating meson decays |
Type |
Journal Article |
| Year |
2026 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
113 |
Issue |
7 |
Pages |
075004 - 24pp |
| Keywords |
|
| Abstract |
Lepton number violating meson decays, such as M-1(-) -> M-2(+) l(1)(-)l(2)(-), provide constraints on d = 9 Delta L = 2 operators. Renormalization group equation (RGE)-improved bounds on the Wilson coefficients of these operators have been presented in the literature, taking into account perturbative quantum chromodynamics (QCD) one-loop corrections and the corresponding operator mixing. Here, we present for the first time the contribution of connected diagrams to the hadronic matrix elements < M2 vertical bar Oh vertical bar M-1 >. These diagrams, usually overlooked under the assumption that < M2 vertical bar Oh|M-1 > similar to < M-2 vertical bar J(q3q4)vertical bar 0 > x < 0 vertical bar J(q1q2)vertical bar M-1 > >> < M-2 vertical bar J(q3q2) x J(q1q4 vertical bar)M(1 >), can give indeed a significant contribution to the matrix element. Including these connected diagrams is but the first step toward a full nonperturbative computation of the long-range QCD effects in these operators, that should be performed using lattice field theory techniques. However, connected diagrams represent the leading order in the 1/N-c expansion of the QCD nonperturbative effects and thus our work can be understood as a realistic, first approximation to a complete calculation of the long-range part of the matrix elements. |
| Address |
[Donini, Andrea; Hirsch, Martin] Univ Valencia, Inst Fis Corpuscular, CSIC, Parc Cientif UV,C Catedrat Jose Beltran 2, E-46980 Paterna, Valencia, Spain, Email: donini@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 |
|
Medium |
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| Area |
|
Expedition |
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Conference |
|
| Notes |
WOS:001738575200001 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
7183 |
| Permanent link to this record |
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| Author |
Arbelaez, C.; Cottin, G.; Helo, J.C.; Hirsch, M.; de Melo, T.B. |
| Title |
Long-lived particle phenomenology in one-loop neutrino mass models with dark matter |
Type |
Journal Article |
| Year |
2025 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
02 |
Issue |
2 |
Pages |
049 - 22pp |
| Keywords |
Dark Matter at Colliders; Models for Dark Matter; Other Weak Scale BSM Models |
| Abstract |
Neutrino masses and dark matter (DM) might have a common origin. The scotogenic model can be considered the proto-type model realizing this idea, but many other variants exist. In this paper we explore the phenomemology of a particular DM neutrino mass model, containing a triplet scalar. We calculate the relic density and check for constraints from direct detection experiments. The parameter space of the model, allowed by these constraints, contains typically a long-lived or quasi-stable doubly charged scalar, that can be searched for at the LHC. We reinterpret existing searches to derive limits on the masses of the scalars of the model and estimate future sensitivities in the high-luminosity phase of the LHC. The searches we discuss can serve to constrain also many other 1-loop neutrino mass models. |
| Address |
[Arbelaez, Carolina] Univ Tecn Federico Santa Maria, Casilla 110-V, Valparaiso, Chile, Email: carolina.arbelaez@usm.cl; |
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Thesis |
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| Publisher |
Springer |
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 |
1029-8479 |
ISBN |
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Medium |
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| Area |
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Expedition |
|
Conference |
|
| Notes |
WOS:001418245700005 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
6513 |
| Permanent link to this record |
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| Author |
Arbelaez, C.; Gonzalez, M.; Hirsch, M.; Neill, N.A.; Restrepo, D. |
| Title |
Effective field theory and scalar triplet dark matter |
Type |
Journal Article |
| Year |
2025 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
04 |
Issue |
4 |
Pages |
118 - 22pp |
| Keywords |
Models for Dark Matter; SMEFT |
| Abstract |
We discuss an extension of the standard model with a real scalar triplet, T, including non-renormalizable operators (NROs) up to d = 6. If T is odd under a Z2 symmetry, the neutral component of T is a good candidate for the dark matter (DM) of the universe. We calculate the relic density and constraints from direct and indirect detection on such a setup, concentrating on the differences with respect to the simple model for a DM T with only renormalizable interactions. Bosonic operators can change the relic density of the triplet drastically, opening up new parameter space for the model. Indirect detection constraints, on the other hand, rule out an interesting part of the allowed parameter space already today and future CTA data will, very likely, provide a decisive test for this setup. |
| Address |
[Arbelaez, Carolina] Univ Tecn Federico Santa Maria, Casilla 110-V, Valparaiso, Chile, Email: carolina.arbelaez@usm.cl; |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
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 |
1029-8479 |
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:001470247500006 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
6616 |
| Permanent link to this record |
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| Author |
Beltran, R.; Cottin, G.; Günther, J.; Hirsch, M.; Titov, A.; Wang, Z.S. |
| Title |
Heavy neutral leptons and top quarks in effective field theory |
Type |
Journal Article |
| Year |
2025 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
05 |
Issue |
5 |
Pages |
238 - 28pp |
| Keywords |
SMEFT; Sterile or Heavy Neutrinos; Top Quark |
| Abstract |
We study the phenomenology of heavy neutral leptons (HNLs) at the LHC in effective field theory, concentrating on d = 6 operators with top quarks. Depending on the operator choice and HNL mass, the HNLs will be produced either from proton-proton collisions in association with a single top, or via non-standard decays of top quarks. For long-lived HNLs we estimate the sensitivity reach of different detectors to various operators with top quarks and the HNLs for the high-luminosity phase of the LHC. For certain operators, ATLAS and some far detectors (MATHUSLA and ANUBIS) will be able to probe the associated new-physics scale as large as 12 TeV and 4.5 TeV, respectively, covering complementary HNL-mass ranges. |
| Address |
[Beltran, Rebeca; Hirsch, Martin] Univ Valencia, CSIC, Inst Fis Corpuscular, AHEP Grp, Apartado 22085, E-46071 Valencia, Spain, Email: rebeca.beltran@ific.uv.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
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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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:001498718300007 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
6689 |
| Permanent link to this record |
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| Author |
Adolf, P.; Hirsch, M.; Krieg, S.; Päs, H.; Tabet, M. |
| Title |
Addendum: Fitting the DESI BAO data with dark energy driven by the Cohen-Kaplan-Nelson bound |
Type |
Journal Article |
| Year |
2025 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
| Volume |
07 |
Issue |
7 |
Pages |
A01 - 10pp |
| Keywords |
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| Abstract |
Motivated by the recent Year-2 data release of the DESI collaboration, we update our results on time-varying dark energy models driven by the Cohen-Kaplan-Nelson bound. The previously found preference of time-dependent dark energy models compared to Lambda CDM is further strengthend by the new data release. For our particular models, we find that this preference increases up to approximate to 2.6 sigma depending on the used supernova dataset. |
| Address |
[Adolf, Patrick; Krieg, Sara; Paes, Heinrich; Tabet, Mustafa] Tech Univ Dortmund, Fak Phys, D-44221 Dortmund, Germany, Email: patrick.adolf@tu-dortmund.de; |
| Corporate Author |
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Thesis |
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| Publisher |
IOP Publishing Ltd |
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 |
1475-7516 |
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:001530576900011 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
6757 |
| Permanent link to this record |
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| Author |
Hirsch, M.; Mantani, L.; Sanz, V. |
| Title |
Data-Driven Discovery Strategy for Standard Model Effective Field Theory Searches |
Type |
Journal Article |
| Year |
2025 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
| Volume |
135 |
Issue |
24 |
Pages |
241801 - 8pp |
| Keywords |
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| Abstract |
We present a novel strategy to uncover indirect signs of new physics in collider data using the standard model effective field theory (SMEFT) framework, offering notably improved sensitivity compared to traditional global analyses. Our approach leverages genetic algorithms to efficiently navigate the high-dimensional space of operator subsets, identifying deformations that improve agreement with data without relying on prior ultraviolet (UV) assumptions. This enables the systematic detection of SMEFT scenarios that outperform the standard model in explaining observed deviations. We validate the approach on current large hadron collider and large electron-positron collider measurements, perform closure tests with injected UV signals, and assess performance under high-luminosity projections. The algorithm successfully recovers relevant operator subsets and highlights directions in parameter space where deviations are most likely to emerge. Our results demonstrate the potential of SMEFT-based discovery searches driven by model selection, providing a scalable framework for future data analyses. |
| Address |
[Hirsch, Martin; Mantani, Luca; Sanz, Veronica] Univ Valencia, Inst Fis Corpuscular IFIC, CSIC, E-46980 Valencia, Spain |
| 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 |
0031-9007 |
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:001645065400021 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
no |
| Call Number |
IFIC @ pastor @ |
Serial |
6997 |
| Permanent link to this record |
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| Author |
Beltran, R.; Günther, J.; Hirsch, M.; Titov, A.; Wang, Z.S. |
| Title |
Heavy neutral leptons from kaons in effective field theory |
Type |
Journal Article |
| Year |
2024 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
| Volume |
109 |
Issue |
11 |
Pages |
115014 - 19pp |
| Keywords |
|
| Abstract |
In the framework of the low -energy effective theory containing, in addition to the Standard -Model fields, heavy neutral leptons (HNLs), we compute the decay rates of neutral and charged kaons into HNLs. We consider both lepton -number -conserving and lepton -number -violating four-fermion operators, taking into account also the contribution of active -heavy neutrino mixing. Assuming that the produced HNLs are longlived, we perform simulations and calculate the sensitivities of future long -lived -particle (LLP) detectors at the high -luminosity LHC as well as the near detector of the Deep Underground Neutrino Experiment (DUNE -ND) to the considered scenario. When applicable, we also recast the existing bounds on the minimal mixing case obtained by NA62, T2K, and PS191. Our findings show that, while the future LHC LLP detectors can probe currently allowed parameter space only in certain benchmark scenarios, DUNE -ND should be sensitive to parameter space beyond the current bounds in almost all the benchmark scenarios, and, for some of the effective operators considered, it can even probe new -physics scales in excess of 3000 TeV. |
| Address |
[Beltran, Rebeca; Hirsch, Martin] Univ Valencia, CSIC, AHEP Grp, Inst Fis Corpuscular, Apartado 22085, E-46071 Valencia, Spain, Email: rebeca.beltran@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:001250419300003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
6165 |
| Permanent link to this record |
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| Author |
Beltran, R.; Bolton, P.D.; Deppisch, F.F.; Hati, C.; Hirsch, M. |
| Title |
Probing heavy neutrino magnetic moments at the LHC using long-lived particle searches |
Type |
Journal Article |
| Year |
2024 |
Publication |
Journal of High Energy Physics |
Abbreviated Journal |
J. High Energy Phys. |
| Volume |
07 |
Issue |
7 |
Pages |
153 - 44pp |
| Keywords |
Neutrino Interactions; Non-Standard Neutrino Properties; Sterile or Heavy Neutrinos; Lepton Flavour Violation (charged) |
| Abstract |
We explore long-lived particle (LLP) searches using non-pointing photons at the LHC as a probe for sterile-to-sterile and active-to-sterile transition magnetic dipole moments of sterile neutrinos. We consider heavy sterile neutrinos with masses ranging from a few GeV to several hundreds of GeV. We discuss transition magnetic dipole moments using the Standard Model effective field theory and low-energy effective field theory extended by sterile neutrinos (NRSMEFT and NRLEFT) and also provide a simplified UV-complete model example. LLP searches at the LHC using non-pointing photons will probe sterile-to-sterile dipole moments two orders of magnitude below the current best constraints from LEP, while an unprecedented sensitivity to sterile neutrino mass of about 700 GeV is expected for active-to-sterile dipole moments. For the UV model example with one-loop transition magnetic moments, the searches for charged lepton flavour violating processes in synergy with LLP searches at the LHC can probe new physics at several TeV mass scales and provide valuable insights into the lepton flavour structure of new physics couplings. |
| Address |
[Beltran, Rebeca; Hati, Chandan; Hirsch, Martin] Univ Valencia, CSIC, Inst Fis Corpuscular, C Catedrat Jose Beltran 2, Paterna 46980, Spain, Email: rebeca.beltran@ific.uv.es; |
| Corporate Author |
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Thesis |
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| Publisher |
Springer |
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 |
1029-8479 |
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:001271719800003 |
Approved |
no |
| Is ISI |
yes |
International Collaboration |
yes |
| Call Number |
IFIC @ pastor @ |
Serial |
6217 |
| Permanent link to this record |
