The 2009 Europhysics Conference on High Energy Physics

We present results on a search for squarks and gluinos performed on data from proton-antiproton collisions collected using the CDF and D0 detectors at the Fermilab Tevatron. Events with multiple jets of hadrons and large missing transverse energy in the final state are studied within the framework of minimal supergravity (mSUGRA) and assuming R-parity conservation. At D0, the search for...

In the Minimal Supersymmetric Standard Model (MSSM), the large mixing between the chiral states of the scalar partnerparticles of the standard model fermions might lead to small masses for sbottom and stop quarks. Dedicated searches are carried out in final states with large missing transverse energy and at least two jets, where at least one of the jets is required to be b-tagged...

The production of coloured supersymmetric particles is an important SUSY discovery channel at the LHC. Therefore it is essential to know the theoretical predictions for squark and gluino production cross sections with high accuracy. Higher order QCD corrections are dominated by the emission of soft gluons from initial and final state particles. The effects of soft gluon emission can...

The talk will review the current strategies to search for generic SUSY models with R-parity conservation in the ATLAS and CMS detectors at the LHC. The discovery reach in early data will be presented for the different search channels based on missing transverse momentum from undetected neutralinos and multiple jets. The talk will also describe the search for models of gauge-mediated...

Any discovery of new physics relies on detailed understanding of the Standard Model background. At the LHC, we expect to extract the backgrounds from the data itself, with minimum reliance on Monte Carlo simulations. We describe new developments in ATLAS and CMS on such data-driven techniques, and prospects for their application on first data.

How should we interpret discovery sensitivity plots and exclusion plots? What are the expected limits vs the actual ones? Was the look elsewhere effect taken into account? Why do Bayesian and frequentist approaches sometimes give very different answers? In a short review we will try to answer these and other questions that some of us wanted to ask but wouldn't dare.

Models of supersymmetry predict new heavy, neutral particles (neutralinos), that can decay into photon and the lightest supersymmetric particle, the gravitino. We present recent results on searches for these particles in proton-antiproton collisions at the Tevatron. No evidence of new physics is found and results are translated in limits on models of Gauge Mediated Supersymmetry Breaking....

The extensions of the minimal supersymmetric model (MSSM), driving mainly from the need to solve the \mu problem, involve novel matter species and gauge groups. These extended MSSM models can be searched for at the LHC via the effects of the gauge and Higgs bosons or their fermionic partners. Traditionally, the focus has been on the study of the extra forces induced by the new gauge and Higgs...

Events with three or more isolated leptons in the final state are known to be signatures of new physics phenomena at high energy collider physics facilities. Standard model sources of isolated trilepton final states include gauge boson pair production such as $WZ$ and $W\gamma^*$, and $t\bar{t}$ production. We demonstrate that leptons from heavy flavor decays, such as $b \to lX$ and $c \to...

Recently, Letters of Intent (LoI) for experiments at the International Linear Collider (ILC) have been submitted. Among the three proposals is the International Large Detector (ILD) concept which is at the focus of these studies. From various subjects addressed in the LoI, a wide spectrum of studies of SUSY particle properties is presented here. Most of them are benchmark reactions for the...

We present a search for a low mass Standard Model Higgs boson produced in association with a W boson at the Fermilab Tevatron collider. The search is performed in events containing one lepton (electron, muon or tau), an imbalance in the transverse energy, and one or two b-tagged jets with about 5 fb-1 of data. This channel is one of the most powerful in the search for a low mass Higgs at the...

We present a search for a low mass Standard Model Higgs boson produced in association with a Z boson decaying to charged leptons or invisibly into a pair of neutrinos at the Fermilab Tevatron collider. The final state is characterised by the presence of two b-tagged jets from the Higgs boson decay and two opposite-sign leptons (electron muon, tau) or a large imbalance in the transverse energy...

We present searches for standard model Higgs production in p-pbar collisions at sqrt(s) = 1.96 TeV using the latest amount of data collected by the CDF and D0 detectors at the Fermilab Tevatron. We consider the diboson decay channel H->WW, the dominant decay mode for Higgs boson masses above 140 GeV/c^2. We also require that both W bosons decay leptonically. In order to maximize sensitivity, a...

We present the combination of the searches for the Standard Model Higgs boson at a center-of-mass energy of sqrt{s}=1.96 TeV, using up to 5 fb-1of data collected with the CDF and D0 detectors at the Tevatron collider. The major contributing processes include associated production (WH and ZH) and gluon fusion (gg to H to WW(*)). The significant improvements across the full mass range resulting...

We search for evidence of a light scalar (e.g. a Higgs boson) in the radiative decays of the narrow Upsilon(2S) and Upsilon(3S) resonances: Upsilon(2S,3S) --> gamma A^0, A^0 --> mu+ mu- and Upsilon(3S) --> gamma A^0, A^0 --> tau+ tau-. Such an object appears in extensions of the Standard Model, where a light CP-odd Higgs boson naturally couples strongly to b-quarks. We find no evidence...

We present results for the mixed QCD-electroweak correction to the Higgs boson production cross section in gluon fusion process arising from light quarks, probing the factorization of QCD and electroweak corrections in this process. We show an updated theoretical prediction for the cross section based on this correction, the best current estimates for contributions from top and bottom...

We present recent MC results and search strategies for low mass Higgs and discuss about measurements of Higgs properties at the LHC. We focus on analysis of H->gamgam, VBF H->tautau, H->bbbar/WW produced with ttbar and vector boson.

We present the discovery potential of the ATLAS and CMS detectors at the LHC for a neutral Higgs boson decaying to ZZ(*) -> 4 leptons (electrons or muons) or to WW(*) -> l nu l' nu' (l or l' = e or mu). The analysis relies on a full simulation of the detector response and emphasis is put on explicit strategies for the measurement of experimental and background systematics from data. We...

The Minimal Supersymmetric extension of the Standard Model (MSSM) predicts the existence of a light neutral Higgs Boson. Once found at the LHC, its mass will immediately become a precision observable. The theoretical value of the Higgs mass is subject to large radiative corrections. Due to the large top Yukawa coupling, loops of top quarks and their superpartners provide the dominant...

We present searches for beyond standard Model Higgs production using the latest amount of data collected by the CDF and D0 detectors at the Fermilab Tevatron. Supersymmetric extensions of the standard model can yield enhanced Higgs production of a neutral MSSM Higgs boson, A, depending on the parameter tan(Beta). Separate searches are carried out for an A decaying to tau leptons or b-quarks,...

The discovery prospects of non Standard Model Higgs bosons with the ATLAS detector are presented. Due to the high branching ratio, results on decay channels that include tau leptons are presented both for the search of the neutral and the charged MSSM Higgs bosons. For the neutral Higgs bosons results on the muon pair final state are also reported. Furthermore, decay scenarios that include...