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Author Bridges, M.; Cranmer, K.; Feroz, F.; Hobson, M.; Ruiz de Austri, R.; Trotta, R. url  doi
openurl 
  Title A coverage study of the CMSSM based on ATLAS sensitivity using fast neural networks techniques Type Journal Article
  Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 03 Issue 3 Pages 012 - 23pp  
  Keywords Supersymmetry; Phenomenology  
  Abstract We assess the coverage properties of confidence and credible intervals on the CMSSM parameter space inferred from a Bayesian posterior and the profile likelihood based on an ATLAS sensitivity study. In order to make those calculations feasible, we introduce a new method based on neural networks to approximate the mapping between CMSSM parameters and weak-scale particle masses. Our method reduces the computational effort needed to sample the CMSSM parameter space by a factor of similar to 10(4) with respect to conventional techniques. We find that both the Bayesian posterior and the profile likelihood intervals can significantly over-cover and identify the origin of this effect to physical boundaries in the parameter space. Finally, we point out that the effects intrinsic to the statistical procedure are conflated with simplifications to the likelihood functions from the experiments themselves.  
  Address [Bridges, Michael; Feroz, Farhan; Hobson, Mike] Univ Cambridge, Cavendish Lab, Astrophys Grp, Cambridge CB3 0HE, England, Email: mb435@mrao.cam.ac.uk  
  Corporate Author Thesis  
  Publisher (up) 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 ISI:000289295200012 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 610  
Permanent link to this record
 

 
Author Casas, J.A.; Moreno, J.M.; Rius, N.; Ruiz de Austri, R.; Zaldivar, B. url  doi
openurl 
  Title Fair scans of the seesaw. Consequences for predictions on LFV processes Type Journal Article
  Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 03 Issue 3 Pages 034 - 22pp  
  Keywords Neutrino Physics; Supersymmetric Standard Model  
  Abstract We give a straightforward procedure to scan the seesaw parameter-space, using the common “R-parametrization”, in a complete way. This includes a very simple rule to incorporate the perturbativity requirement as a condition for the entries of the R-matrix. As a relevant application, we show that the somewhat propagated belief that BR(mu -> e, gamma) in supersymmetric seesaw models depends strongly on the value of theta(13) is an “optical effect” produced by incomplete scans, and does not hold after a careful analytical and numerical study. When the complete scan is done, BR(mu -> e, gamma) gets very insensitive to theta(13). This holds even if the right-handed neutrino masses are kept constant or under control (as is required for succesful leptogenesis). In most cases the values of BR(mu -> e, gamma) are larger than the experimental upper bound. Including (unflavoured) leptogenesis does not introduce any further dependence on theta(13), although decreases the typical value of BR(mu -> e, gamma).  
  Address [Alberto Casas, J.; Moreno, Jesus M.; Zaldivar, Bryam] UAM, IFT UAM CSIC, Inst Fis Teor, Madrid 28049, Spain, Email: alberto.casas@uam.es  
  Corporate Author Thesis  
  Publisher (up) 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 ISI:000289295200034 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 612  
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Author Feroz, F.; Cranmer, K.; Hobson, M.; Ruiz de Austri, R.; Trotta, R. url  doi
openurl 
  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 (up) 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 Fidalgo, J.; Lopez-Fogliani, D.E.; Muñoz, C.; Ruiz de Austri, R. url  doi
openurl 
  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 (up) 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 Cabrera, M.E.; Casas, J.A.; Mitsou, V.A.; Ruiz de Austri, R.; Terron, J. url  doi
openurl 
  Title Histogram comparison tools for the search of new physics at LHC. Application to the CMSSM Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 04 Issue 4 Pages 133 - 27pp  
  Keywords Beyond Standard Model; Supersymmetric Standard Model; Statistical Methods  
  Abstract We propose a rigorous and effective way to compare experimental and theoretical histograms, incorporating the different sources of statistical and systematic uncertainties. This is a useful tool to extract as much information as possible from the comparison between experimental data with theoretical simulations, optimizing the chances of identifying New Physics at the LHC. We illustrate this by showing how a search in the CMSSM parameter space, using Bayesian techniques, can effectively find the correct values of the CMSSM parameters by comparing histograms of events with multijets + missing transverse momentum displayed in the effective-mass variable. The procedure is in fact very efficient to identify the true supersymmetric model, in the case supersymmetry is really there and accessible to the LHC.  
  Address [Eugenia Cabrera, Maria; Alberto Casas, J.] UAM, IFT UAM CSIC, Inst Fis Teor, E-28049 Madrid, Spain, Email: maria.cabrera@uam.es;  
  Corporate Author Thesis  
  Publisher (up) 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:000304148100059 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 1053  
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Author Cabrera, M.E.; Casas, J.A.; Ruiz de Austri, R. url  doi
openurl 
  Title The health of SUSY after the Higgs discovery and the XENON100 data Type Journal Article
  Year 2013 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 182 - 47pp  
  Keywords Supersymmetry Phenomenology  
  Abstract We analyze the implications for the status and prospects of supersymmetry of the Higgs discovery and the last XENON data. We focus mainly, but not only, on the CMSSM and NUHM models. Using a Bayesian approach we determine the distribution of probability in the parameter space of these scenarios. This shows that, most probably, they are now beyond the LHC reach. This negative chances increase further (at more than 95% c.l.) if one includes dark matter constraints in the analysis, in particular the last XENON100 data. However, the models would be probed completely by XENON1T. The mass of the LSP neutralino gets essentially fixed around 1TeV. We do not incorporate ad hoc measures of the fine-tuning to penalize unnatural possibilities: such penalization arises automatically from the careful Bayesian analysis itself, and allows to scan the whole parameter space. In this way, we can explain and resolve the apparent discrepancies between the previous results in the literature. Although SUSY has become hard to detect at LHC, this does not necessarily mean that is very fine-tuned. We use Bayesian techniques to show the experimental Higgs mass is at similar to 2 sigma off the CMSSM or NUHM expectation. This is substantial but not dramatic. Although the CMSSM or the NUHM are unlikely to show up at the LHC, they are still interesting and plausible models after the Higgs observation; and, if they are true, the chances of discovering them in future dark matter experiments are quite high.  
  Address [Cabrera, Maria Eugenia] Univ Amsterdam, Inst Theoret Phys, GRAPPA, NL-1012 WX Amsterdam, Netherlands, Email: M.E.CabreraCatalan@uva.nl;  
  Corporate Author Thesis  
  Publisher (up) 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:000323202900095 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1572  
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Author TLEP Design Study Working Group (Bicer, M. et al); Ruiz de Austri, R. url  doi
openurl 
  Title First look at the physics case of TLEP Type Journal Article
  Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 01 Issue 1 Pages 164 - 49pp  
  Keywords e plus -e- Experiments  
  Abstract The discovery by the ATLAS and CMS experiments of a new boson with mass around 125 GeV and with measured properties compatible with those of a Standard-Model Higgs boson, coupled with the absence of discoveries of phenomena beyond the Standard Model at the TeV scale, has triggered interest in ideas for future Higgs factories. A new circular e(+)e(-) collider hosted in a 80 to 100 km tunnel, TLEP, is among the most attractive solutions proposed so far. It has a clean experimental environment, produces high luminosity for top-quark, Higgs boson, W and Z studies, accommodates multiple detectors, and can reach energies up to the threshold and beyond. It will enable measurements of the Higgs boson properties and of Electroweak Symmetry-Breaking (EWSB) parameters with unequalled precision, offering exploration of physics beyond the Standard Model in the multi-TeV range. Moreover, being the natural precursor of the VHE-LHC, a 100 TeV hadron machine in the same tunnel, it builds up a long-term vision for particle physics. Altogether, the combination of TLEP and the VHE-LHC offers, for a great cost effectiveness, the best precision and the best search reach of all options presently on the market. This paper presents a first appraisal of the salient features of the TLEP physics potential, to serve as a baseline for a more extensive design study.  
  Address [Bicer, M.] Ankara Univ, Fac Sci, TR-06100 Ankara, Turkey, Email: TLEP3-steering-group@cern.ch  
  Corporate Author Thesis  
  Publisher (up) 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:000330992300001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1700  
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Author Strege, C.; Bertone, G.; Besjes, G.J.; Caron, S.; Ruiz de Austri, R.; Strubig, A.; Trotta, R. url  doi
openurl 
  Title Profile likelihood maps of a 15-dimensional MSSM Type Journal Article
  Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 09 Issue 9 Pages 081 - 59pp  
  Keywords Supersymmetry Phenomenology  
  Abstract We present statistically convergent profile likelihood maps obtained via global fits of a phenomenological Minimal Supersymmetric Standard Model with 15 free parameters (the MSSM-15), based on over 250M points. We derive constraints on the model parameters from direct detection limits on dark matter, the Planck relic density measurement and data from accelerator searches. We provide a detailed analysis of the rich phenomenology of this model, and determine the SUSY mass spectrum and dark matter properties that are preferred by current experimental constraints. We evaluate the impact of the measurement of the anomalous magnetic moment of the muon (g – 2) on our results, and provide an analysis of scenarios in which the lightest neutralino is a subdominant component of the dark matter. The MSSM-15 parameters are relatively weakly constrained by current data sets, with the exception of the parameters related to dark matter phenomenology (M-1, M-2, mu), which are restricted to the sub-TeV regime, mainly due to the relic density constraint. The mass of the lightest neutralino is found to be < 1.5TeV at 99% C.L., but can extend up to 3 TeV when excluding the g – 2 constraint from the analysis. Low-mass bino-like neutralinos are strongly favoured, with spin-independent scattering cross-sections extending to very small values, similar to 10(-20) pb. ATLAS SUSY null searches strongly impact on this mass range, and thus rule out a region of parameter space that is outside the reach of any current or future direct detection experiment. The best-fit point obtained after inclusion of all data corresponds to a squark mass of 2.3 TeV, a gluino mass of 2.1 TeV and a 130 GeV neutralino with a spin-independent cross-section of 2.4 x 10(-10) pb, which is within the reach of future multi-ton scale direct detection experiments and of the upcoming LHC run at increased centre-of-mass energy.  
  Address [Strege, C.; Trotta, R.] Univ London Imperial Coll Sci Technol & Med, Imperial Ctr Inference & Cosmol, Blackett Lab, Astrophys Grp, London SW7 2AZ, England, Email: charlotte.strege09@imperial.ac.uk;  
  Corporate Author Thesis  
  Publisher (up) 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:000342069700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1934  
Permanent link to this record
 

 
Author Ghosh, P.; Lopez-Fogliani, D.E.; Mitsou, V.A.; Muñoz, C.; Ruiz de Austri, R. url  doi
openurl 
  Title Probing the μnu SSM with light scalars, pseudoscalars and neutralinos from the decay of a SM-like Higgs boson at the LHC Type Journal Article
  Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 11 Issue 11 Pages 102 - 57pp  
  Keywords Supersymmetry Phenomenology  
  Abstract The “mu from nu” supersymmetric standard model (mu nu SSM) can accommodate the newly discovered Higgs-like scalar boson with a mass around 125GeV. This model provides a solution to the mu-problem and simultaneously reproduces correct neutrino physics by the simple use of right-handed neutrino superfields. These new superfields together with the introduced R-parity violation can produce novel and characteristic signatures of the μnu SSM at the LHC. We explore the signatures produced through two-body Higgs decays into the new states, provided that these states lie below in the mass spectrum. For example, a pair produced light neutralinos depending on the associated decay length can give rise to displaced multi-leptons/taus/jets/photons with small/moderate missing transverse energy. In the same spirit, a Higgs-like scalar decaying to a pair of scalars/pseudoscalars can produce final states with prompt multi-leptons/taus/jets/photons.  
  Address [Ghosh, Pradipta; Munoz, Carlos] Univ Autonoma Madrid, Dept Fis Teor, E-28049 Madrid, Spain, Email: pradipta.ghosh@uam.es;  
  Corporate Author Thesis  
  Publisher (up) 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:000345590600002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2016  
Permanent link to this record
 

 
Author Cabrera, M.E.; Casas, A.; Ruiz de Austri, R.; Bertone, G. url  doi
openurl 
  Title LHC and dark matter phenomenology of the NUGHM Type Journal Article
  Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 12 Issue 12 Pages 114 - 39pp  
  Keywords Supersymmetry Phenomenology  
  Abstract We present a Bayesian analysis of the NUGHM, a supersymmetric scenario with non-universal gaugino masses and Higgs masses, including all the relevant experimental observables and dark matter constraints. The main merit of the NUGHM is that it essentially includes all the possibilities for dark matter (DM) candidates within the MSSM, since the neutralino and chargino spectrum -and composition- are as free as they can be in the general MSSM. We identify the most probable regions in the NUHGM parameter space, and study the associated phenomenology at the LHC and the prospects for DM direct detection. Requiring that the neutralino makes all of the DM in the Universe, we identify two preferred regions around m(chi 10) = 1 TeV, 3 TeV, which correspond to the (almost) pure Higgsino and wino case. There exist other marginal regions (e.g. Higgs-funnel), but with much less statistical weight. The prospects for detection at the LHC in this case are quite pessimistic, but future direct detection experiments like LUX and XENON1T, will be able to probe this scenario. In contrast, when allowing other DM components, the prospects for detection at the LHC become more encouraging – the most promising signals being, beside the production of gluinos and squarks, the production of the heavier chargino and neutralino states, which lead to WZ and same-sign WW final states – and direct detection remains a complementary, and even more powerful, way to probe the scenario.  
  Address [Cabrera, Maria Eugenia; Bertone, Gianfranco] Univ Amsterdam, Inst Theoret Phys, GRAPPA, NL-1018 XE Amsterdam, Netherlands, Email: mcabrera@if.usp.br;  
  Corporate Author Thesis  
  Publisher (up) 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:000346771200001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 2063  
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