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Author (up) Felea, D.; Mamuzic, J.; Maselek, R.; Mavromatos, N.E.; Mitsou, V.A.; Pinfold, J.L.; Ruiz de Austri, R.; Sakurai, K.; Santra, A.; Vives, O.
Title Prospects for discovering supersymmetric long-lived particles with MoEDAL Type Journal Article
Year 2020 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 80 Issue 5 Pages 431 - 12pp
Keywords
Abstract We present a study on the possibility of searching for long-lived supersymmetric partners with the MoEDAL experiment at the LHC. MoEDAL is sensitive to highly ionising objects such as magnetic monopoles or massive (meta)stable electrically charged particles. We focus on prospects of directly detecting long-lived sleptons in a phenomenologically realistic model which involves an intermediate neutral long-lived particle in the decay chain. This scenario is not yet excluded by the current data from ATLAS or CMS, and is compatible with astrophysical constraints. Using Monte Carlo simulation, we compare the sensitivities of MoEDAL versus ATLAS in scenarios where MoEDAL could provide discovery reach complementary to ATLAS and CMS, thanks to looser selection criteria combined with the virtual absence of background. It is also interesting to point out that, in such scenarios, in which charged staus are the main long-lived candidates, the relevant mass range for MoEDAL is compatible with a potential role of Supersymmetry in providing an explanation for the anomalous events observed by the ANITA detector.
Address [Felea, D.] Inst Space Sci, POB MG 23, Bucharest 077125, Magurele, Romania, Email: daniel.felea@cern.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:000536572700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4411
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Author (up) Feroz, F.; Cranmer, K.; Hobson, M.; Ruiz de Austri, R.; Trotta, R.
Title Challenges of profile likelihood evaluation in multi-dimensional SUSY scans Type Journal Article
Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 06 Issue 6 Pages 042 - 23pp
Keywords Supersymmetry Phenomenology
Abstract Statistical inference of the fundamental parameters of supersymmetric theories is a challenging and active endeavor. Several sophisticated algorithms have been employed to this end. While Markov-Chain Monte Carlo (MCMC) and nested sampling techniques are geared towards Bayesian inference, they have also been used to estimate frequentist confidence intervals based on the profile likelihood ratio. We investigate the performance and appropriate configuration of MULTINEST, a nested sampling based algorithm, when used for profile likelihood-based analyses both on toy models and on the parameter space of the Constrained MSSM. We find that while the standard configuration previously used in the literarture is appropriate for an accurate reconstruction of the Bayesian posterior, the profile likelihood is poorly approximated. We identify a more appropriate MULTINEST configuration for profile likelihood analyses, which gives an excellent exploration of the profile likelihood (albeit at a larger computational cost), including the identification of the global maximum likelihood value. We conclude that with the appropriate configuration MULTINEST is a suitable tool for profile likelihood studies, indicating previous claims to the contrary are not well founded.
Address [Feroz, F; Hobson, M] Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England, Email: f.feroz@mrao.cam.ac.uk
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 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000293136500042 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 745
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Author (up) Ferrer-Sanchez, A.; Martin-Guerrero, J.; Ruiz de Austri, R.; Torres-Forne, A.; Font, J.A.
Title Gradient-annihilated PINNs for solving Riemann problems: Application to relativistic hydrodynamics Type Journal Article
Year 2024 Publication Computer Methods in Applied Mechanics and Engineering Abbreviated Journal Comput. Meth. Appl. Mech. Eng.
Volume 424 Issue Pages 116906 - 18pp
Keywords Riemann problem; Euler equations; Machine learning; Neural networks; Relativistic hydrodynamics
Abstract We present a novel methodology based on Physics-Informed Neural Networks (PINNs) for solving systems of partial differential equations admitting discontinuous solutions. Our method, called Gradient-Annihilated PINNs (GA-PINNs), introduces a modified loss function that forces the model to partially ignore high-gradients in the physical variables, achieved by introducing a suitable weighting function. The method relies on a set of hyperparameters that control how gradients are treated in the physical loss. The performance of our methodology is demonstrated by solving Riemann problems in special relativistic hydrodynamics, extending earlier studies with PINNs in the context of the classical Euler equations. The solutions obtained with the GA-PINN model correctly describe the propagation speeds of discontinuities and sharply capture the associated jumps. We use the relative l(2) error to compare our results with the exact solution of special relativistic Riemann problems, used as the reference ''ground truth'', and with the corresponding error obtained with a second-order, central, shock-capturing scheme. In all problems investigated, the accuracy reached by the GA-PINN model is comparable to that obtained with a shock-capturing scheme, achieving a performance superior to that of the baseline PINN algorithm in general. An additional benefit worth stressing is that our PINN-based approach sidesteps the costly recovery of the primitive variables from the state vector of conserved variables, a well-known drawback of grid-based solutions of the relativistic hydrodynamics equations. Due to its inherent generality and its ability to handle steep gradients, the GA-PINN methodology discussed in this paper could be a valuable tool to model relativistic flows in astrophysics and particle physics, characterized by the prevalence of discontinuous solutions.
Address [Ferrer-Sanchez, Antonio; Martin-Guerrero, JoseD.] ETSE UV, Elect Engn Dept, IDAL, Avgda Univ S-N, Valencia 46100, Spain, Email: Antonio.Ferrer-Sanchez@uv.es
Corporate Author Thesis
Publisher Elsevier Science Sa Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0045-7825 ISBN Medium
Area Expedition Conference
Notes WOS:001221797400001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 6126
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Author (up) Fidalgo, J.; Lopez-Fogliani, D.E.; Muñoz, C.; Ruiz de Austri, R.
Title The Higgs sector of the μnu SSM and collider physics Type Journal Article
Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 10 Issue 10 Pages 020 - 33pp
Keywords Higgs Physics; Supersymmetric Effective Theories; Beyond Standard Model
Abstract The μnu SSM is a supersymmetric standard model that accounts for light neutrino masses and solves the μproblem of the MSSM by simply using right-handed neutrino superfields. Since this mechanism breaks R-parity, a peculiar structure for the mass matrices is generated. The neutral Higgses are mixed with the right- and left-handed sneutrinos producing 8x8 neutral scalar mass matrices. We analyse the Higgs sector of the μnu SSM in detail, with special emphasis in possible signals at colliders. After studying in general the decays of the Higges, we focus on those processes that are genuine of the μnu SSM, and could serve to distinguish it form other supersymmetric models. In particular, we present viable benchmark points for LHC searches. For example, we find decays of a MSSM-like Higgs into two lightest neutralinos, with the latter decaying inside the detector leading to displaced vertices, and producing final states with 4 and 8 b-jets plus missing energy. Final states with leptons and missing energy are also found.
Address [Fidalgo, Javier; Munoz, Carlos] Univ Autonoma Madrid, Dept Fis Teor UAM, E-28049 Madrid, Spain, Email: javier.fidalgo@uam.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 1126-6708 ISBN Medium
Area Expedition Conference
Notes WOS:000296917100020 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 831
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Author (up) Flores, M.M.; Kim, J.S.; Rolbiecki, K.; Ruiz de Austri, R.
Title Updated LHC bounds on MUED after run 2 Type Journal Article
Year 2023 Publication International Journal of Modern Physics A Abbreviated Journal Int. J. Mod. Phys. A
Volume 38 Issue 1 Pages 2350002 - 14pp
Keywords Universal extra dimensions; large hadron collider; phenomenology
Abstract We present updated LHC limits on the minimal universal extra dimensions (MUEDs) model from the Run 2 searches. We scan the parameter space against a number of searches implemented in the public code CheckMATE and derive up-to-date limits on the MUED parameter space from 13TeV searches. The strongest constraints come from a search dedicated to squarks and gluinos with one isolated lepton, jets and missing transverse energy. In the procedure, we take into account initial state radiation and stress its importance in the MUED searches, which is not always appreciated.
Address [Flores, Marvin M.] Univ Philippines, Natl Inst Phys, Diliman, Quezon City, Philippines, Email: mflores@nip.upd.edu.ph
Corporate Author Thesis
Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0217-751x ISBN Medium
Area Expedition Conference
Notes WOS:000936994000001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5487
Permanent link to this record