Inclusive SUSY searches at the LHC

I summarize the status of the inclusive SUSY searches conducted by the ATLAS and CMS experiments using the 20 fb-1 of 8 TeV LHC data in the all inclusive, 0 lepton, >=1 lepton and >=2 lepton final states. Current searches show that data are consistent with the SM. The impact of this consistency was explored on a rich variety of SUSY scenarios and simplified models, examples of which I present here.Comment: To appear in the proceedings of the 49th Rencontres de Moriond: QCD and Hadronic Interactions, La Thuile, Italy, 22-29 March 201

Status of CMS dark matter searches in 2011

We present the status of dark matter searches performed by the Compact Muon Solenoid Experiment using 7 TeV pp data collected by the CERN Large Hadron Collider in 2010 and 2011. The majority of the results shown here were obtained using 1.1 fb-1 of data. We give highlights from analyses searching for candidates such as WIMPs, gravitinos, axinos and TeV scale particles. All observations so far were found to be consistent with the Standard Model predictions. The search results were used to set exclusion limits on various new physics scenarios.Comment: Contribution to the proceedings of Balkan Workshop 2011 (BW2011, 28 August - 1 September 2011, Donji Milanovac, Serbia

Search for Natural SUSY with inclusive search strategies at the LHC using the CMS detector

Natural SUSY suggests the existence of light stop quarks, accessible at the LHC, which are the focus of a dedicated CMS search program. I present two inclusive CMS searches that look for TeV scale colored sparticles in final states with jets, b-tagged jets and missing transverse energy performed using up to 19.4fb-1 of 8TeV LHC proton-proton data. No deviation from the Standard Model was observed in these searches, and the implications for this was shown for several simplified model scenarios and phenomenological MSSM.Comment: Proceedings for The European Physical Society Conference on High Energy Physics - EPS-HEP2013, 18-24 July 2013, Stockholm, Swede

Shear critical R/C columns under increasing axial load

Structural elements in old reinforced concrete (R/C) frame buildings are often prone to shear or flexure-shear failure, which can eventually lead to loss of axial load capacity of vertical elements and initiate vertical progressive collapse of a building. An experimental investigation of shear and flexure-shear critical R/C elements subjected to increasing axial load is reported herein. The focus is on the effect of vertical load redistribution from axially failing columns on the non-linear (pre- and post-peak) response of neighboring shear-dominated members. The test results along with an analysis of the recorded deformation, strength, stiffness and energy dissipation characteristics shed light on the performance of sub-standard columns under constant and increasing axial load subsequent, or just prior, to failing in shear, thus providing useful insights into the assessment of existing R/C structures

Multiscale Bayesian State Space Model for Granger Causality Analysis of Brain Signal

Modelling time-varying and frequency-specific relationships between two brain signals is becoming an essential methodological tool to answer heoretical questions in experimental neuroscience. In this article, we propose to estimate a frequency Granger causality statistic that may vary in time in order to evaluate the functional connections between two brain regions during a task. We use for that purpose an adaptive Kalman filter type of estimator of a linear Gaussian vector autoregressive model with coefficients evolving over time. The estimation procedure is achieved through variational Bayesian approximation and is extended for multiple trials. This Bayesian State Space (BSS) model provides a dynamical Granger-causality statistic that is quite natural. We propose to extend the BSS model to include the \`{a} trous Haar decomposition. This wavelet-based forecasting method is based on a multiscale resolution decomposition of the signal using the redundant \`{a} trous wavelet transform and allows us to capture short- and long-range dependencies between signals. Equally importantly it allows us to derive the desired dynamical and frequency-specific Granger-causality statistic. The application of these models to intracranial local field potential data recorded during a psychological experimental task shows the complex frequency based cross-talk between amygdala and medial orbito-frontal cortex. Keywords: \`{a} trous Haar wavelets; Multiple trials; Neuroscience data; Nonstationarity; Time-frequency; Variational methods The published version of this article is Cekic, S., Grandjean, D., Renaud, O. (2018). Multiscale Bayesian state-space model for Granger causality analysis of brain signal. Journal of Applied Statistics. https://doi.org/10.1080/02664763.2018.145581

Individually mark–mass release–resight study elucidates effects of patch characteristics and distance on host patch location by an insect herbivore

1. How organisms locate their hosts is of fundamental importance in a variety of basic and applied ecological fields, including population dynamics, invasive species management and biological control. However, tracking movement of small organisms, such as insects, poses significant logistical challenges. 2. Mass-release and individual–mark–recapture techniques were combined in an individually mark–mass release–resight (IMMRR) approach to track the movement of over 2000 adult insects in an economically important plant–herbivore system. Despite its widespread use for the biological control of the invasive thistle Carduus nutans, the host-finding behaviour of the thistle head weevil Rhinocyllus conicus has not previously been studied. Insects were released at different distances from a mosaic of artificially created host patches with different areas and number of plants to assess the ecological determinants of patch finding. 3. The study was able to characterize the within-season dispersal abilities and between-patch movement patterns of R. conicus. Weevils found host plant patches over 900 m away. Large patches, with tall plants, situated close to the nearest release point had the highest first R. conicusresights. Patch area and plant density had no effect on the number of weevils resighted per plant; however, R. conicus individuals were more likely to disperse out of small patches and into large patches. 4. By understanding how R. conicus locates host patches of C. nutans, management activities for the control of this invasive thistle can be better informed. A deeper mechanistic understanding of host location will also improve prediction of coupled plant–herbivore spatial dynamics in general

Reconciling thermal leptogenesis with the gravitino problem in SUSY models with mixed axion/axino dark matter

Successful implementation of thermal leptogenesis requires re-heat temperatures T_R\agt 2\times 10^9 GeV, in apparent conflict with SUSY models with TeV-scale gravitinos, which require much lower T_R in order to avoid Big Bang Nucleosynthesis (BBN) constraints. We show that mixed axion/axino dark matter can reconcile thermal leptogenesis with the gravitino problem in models with m_{\tG}\agt 30 TeV, a rather high Peccei-Quinn breaking scale and an initial mis-alignment angle \theta_i < 1. We calculate axion and axino dark matter production from four sources, and impose BBN constraints on long-lived gravitinos and neutralinos. Moreover, we discuss several SUSY models which naturally have gravitino masses of the order of tens of TeV. We find a reconciliation difficult in Yukawa-unified SUSY and in AMSB with a wino-like lightest neutralino. However, T_R\sim 10^{10}-10^{12} GeV can easily be achieved in effective SUSY and in models based on mixed moduli-anomaly mediation. Consequences of this scenario include: 1. an LHC SUSY discovery should be consistent with SUSY models with a large gravitino mass, 2. an apparent neutralino relic abundance \Omega_{\tz_1}h^2\alt 1, 3. no WIMP direct or indirect detection signals should be found, and 4. the axion mass should be less than \sim 10^{-6} eV, somewhat below the conventional range which is explored by microwave cavity axion detection experiments.Comment: 25 pages including 15 .eps figures; updated version to coincide with published versio