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Author Debastiani, V.R.; Sakai, S.; Oset, E.
Title (up) Considerations on the Schmid theorem for triangle singularities Type Journal Article
Year 2019 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 79 Issue 1 Pages 69 - 13pp
Keywords
Abstract We investigate the Schmid theorem, which states that if one has a tree level mechanism with a particle decaying to two particles and one of them decaying posteriorly to two other particles, the possible triangle singularity developed by the mechanism of elastic rescattering of two of the three decay particles does not change the cross section provided by the tree level. We investigate the process in terms of the width of the unstable particle produced in the first decay and determine the limits of validity and violation of the theorem. One of the conclusions is that the theorem holds in the strict limit of zero width of that resonance, in which case the strength of the triangle diagram becomes negligible compared to the tree level. Another conclusion, on the practical side, is that for realistic values of the width, the triangle singularity can provide a strength comparable or even bigger than the tree level, which indicates that invoking the Schmid theorem to neglect the triangle diagram stemming from elastic rescattering of the tree level should not be done. Even then, we observe that the realistic case keeps some memory of the Schmid theorem, which is visible in a peculiar interference pattern with the tree level.
Address [Debastiani, V. R.; Sakai, S.; Oset, E.] Ctr Mixto Univ Valencia, CSIC, Inst Invest Paterna, Dept Fis Teor, Aptdo 22085, Valencia 46071, Spain, Email: vinicius.rodrigues@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 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000456999600008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3904
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Author Desai, N.; Domingo, F.; Kim, J.S.; Ruiz de Austri, R.; Rolbiecki, K.; Sonawane, M.; Wang, Z.S.
Title (up) Constraining electroweak and strongly charged long-lived particles with CheckMATE Type Journal Article
Year 2021 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 81 Issue 11 Pages 968 - 19pp
Keywords
Abstract Long-lived particles have become a new frontier in the exploration of physics beyond the Standard Model. In this paper, we present the implementation of four types of long-lived particle searches, viz. displaced leptons, disappearing track, displaced vertex with either muons or with missing transverse energy, and heavy charged tracks. These four categories cover the signatures of a large range of physics models. We illustrate their potential for exclusion and discuss their mutual overlaps in mass-lifetime space for two simple phenomenological models involving either a U(1)-charged or a coloured scalar.
Address [Desai, Nishita] Tata Inst Fundamental Res, Dept Theoret Phys, Mumbai 400005, Maharashtra, India, Email: nishita.desai@tifr.res.in;
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 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000714374500002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5015
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Author Mongillo, M.; Abdullahi, A.; Banto Oberhauser, B.; Crivelli, P.; Hostert, M.; Massaro, D.; Molina Bueno, L.; Pascoli, S.
Title (up) Constraining light thermal inelastic dark matter with NA64 Type Journal Article
Year 2023 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 83 Issue 5 Pages 391 - 14pp
Keywords
Abstract A vector portal between the Standard Model and the dark sector is a predictive and compelling framework for thermal dark matter. Through co-annihilations, models of inelastic dark matter (iDM) and inelastic Dirac dark matter (i2DM) can reproduce the observed relic density in the MeV to GeV mass range without violating cosmological limits. In these scenarios, the vector mediator behaves like a semi-visible particle, evading traditional bounds on visible or invisible resonances, and uncovering new parameter space to explain the muon (g – 2) anomaly. By means of a more inclusive signal definition at the NA64 experiment, we place new constraints on iDM and i2DM using a missing energy technique. With a recast-based analysis, we contextualize the NA64 exclusion limits in parameter space and estimate the reach of the newly collected and expected future NA64 data. Our results motivate the development of an optimized search program for semi-visible particles, in which fixed target experiments like NA64 provide a powerful probe in the sub-GeV mass range.
Address [Mongillo, Martina; Oberhauser, Benjamin Banto; Crivelli, Paolo] Swiss Fed Inst Technol, Inst Particle Phys & Astrophys, CH-8093 Zurich, Switzerland, Email: mmongillo@phys.ethz.ch;
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 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000986592700002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5548
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Author Gonzalez Felipe, R.; Ivanov, I.P.; Nishi, C.C.; Serodio, H.; Silva, J.P.
Title (up) Constraining multi-Higgs flavour models Type Journal Article
Year 2014 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 74 Issue 7 Pages 2953 - 12pp
Keywords
Abstract To study a flavour model with a non-minimal Higgs sector one must first define the symmetries of the fields; then identify what types of vacua exist and how they may break the symmetries; and finally determine whether the remnant symmetries are compatible with the experimental data. Here we address all these issues in the context of flavour models with any number of Higgs doublets. We stress the importance of analysing the Higgs vacuum expectation values that are pseudo-invariant under the generators of all subgroups. It is shown that the only way of obtaining a physical CKM mixing matrix and, simultaneously, non-degenerate and non-zero quark masses is requiring the vacuum expectation values of the Higgs fields to break completely the full flavour group, except possibly for some symmetry belonging to baryon number. The application of this technique to some illustrative examples, such as the flavour groups Delta (27), A(4) and S-3, is also presented.
Address [Gonzalez Felipe, R.; Silva, Joao P.] ISEL, P-1959007 Lisbon, Portugal, Email: gonzalez@cftp.ist.utl.pt;
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 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000350743900002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2126
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Author Gariazzo, S.
Title (up) Constraining power of open likelihoods, made prior-independent Type Journal Article
Year 2020 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 80 Issue 6 Pages 552 - 6pp
Keywords
Abstract One of the most criticized features of Bayesian statistics is the fact that credible intervals, especially when open likelihoods are involved, may strongly depend on the prior shape and range. Many analyses involving open likelihoods are affected by the eternal dilemma of choosing between linear and logarithmic prior, and in particular in the latter case the situation is worsened by the dependence on the prior range under consideration. In this letter, we revive a simple method to obtain constraints that depend neither on the prior shape nor range and, using the tools of Bayesian model comparison, extend it to overcome the possible dependence of the bounds on the choice of free parameters in the numerical analysis. An application to the case of cosmological bounds on the sum of the neutrino masses is discussed as an example.
Address [Gariazzo, S.] Univ Valencia, CSIC, Inst Fis Corpuscular, Parc Cient UV,C Catedrat Jose Beltran 2, Valencia 46980, Spain, Email: gariazzo@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 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000542940000007 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4446
Permanent link to this record