Results are presented from searches for the standard model Higgs boson in proton-proton collisions at root s = 7 and 8 TeV in the Compact Muon Solenoid experiment at the LHC, using data samples corresponding to integrated luminosities of up to 5.1 fb(-1) at 7 TeV and 5.3 fb(-1) at 8 TeV. The search is performed in five decay modes: gamma gamma, ZZ, W+W-, tau(+)tau(-), and b (b) over bar. An excess of events is observed above the expected background, with a local significance of 5.0 standard deviations, at a mass near 125 GeV, signalling the production of a new particle. The expected significance for a standard model Higgs boson of that mass is 5.8 standard deviations. The excess is most significant in the two decay modes with the best mass resolution, gamma gamma and ZZ; a fit to these signals gives a mass of 125.3 +/- 0.4(stat.) +/- 0.5(syst.) GeV. The decay to two photons indicates that the new particle is a boson with spin different from one. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved

We discuss issues in an attempt to put the Standard Model (SM) in fivedimensional anti-de Sitter spacetime compactified on S 1 /Z 2 . The recentlyproposed approach to the gauge hierarchy problem by using this background geometry, with the SM confined on a boundary, is extended to a situation where (some of) the SM particles reside in the five dimensional bulk. In particular, we find a localization of zero modes of bulk fermions near the boundary with a negative tension. Unlike the compactification with the flat metric, these fermion zero modes couple to Kaluza-Klein (KK) excitations of the SM gauge bosons. Interestingly, only low-lying modes of such KK gauge bosons have non-negligible couplings. Current electroweak precision data give a constraint that the first KK mode be heavier than 9 TeV. We also argue that at least the Higgs field should be confined on the brane to utilize the Randall-Sundrum background as a solution to the gauge hierarchy.

No abstract

A search for events with jets and missing transverse energy is performed in a data sample of pp collisions collected at ffiffi ffi s p ¼ 7 TeV by the CMS experiment at the LHC. The analyzed data sample corresponds to an integrated luminosity of 1:14 fb À1 . In this search, a kinematic variable T is used as the main discriminator between events with genuine and misreconstructed missing transverse energy. The standard model (SM) of particle physics is generally considered to be valid only at low energy scales and is expected to be superseded by a more complete theory at higher scales. Supersymmetric (SUSY) extensions to the SM [1-8] introduce a large number of new particles with the same quantum numbers as their SM partners, but differing by half a unit of spin. If R-parity conservation [9] is assumed, supersymmetric particles, such as squarks and gluinos, are produced in pairs and decay to the lightest, stable supersymmetric particle (LSP . This Letter presents a search for SUSY based on a data sample corresponding to an integrated luminosity of 1:14 AE 0:05 fb À1 . The search strategy follows Ref.[23] and is designed to be sensitive to 6 E T signatures in events with two or more energetic jets. The search is not optimized for any particular model of SUSY and is applicable to other new physics scenarios with a 6 E T signature. In this Letter, nevertheless, the results are interpreted in the constrained minimal supersymmetric extension of the standard model (CMSSM) [28][29][30]. The CMSSM is described by the following five parameters: the universal scalar and gaugino mass parameters, m 0 and m 1=2 ; the universal trilinear soft SUSY-breaking parameter, A 0 ; the ratio of the vacuum expectation values of the two Higgs doublets, tan; and the sign of the Higgs mixing parameter, . We consider only parameter sets for which the LSP is the lightest neutralino. The following example parameter set, referred to as LM6, is used to illustrate possible CMSSM yields: m 0 ¼ 85 GeV, m 1=2 ¼ 400 GeV, A 0 ¼ 0, tan ¼ 10, and > 0.A detailed description of the CMS apparatus can be found in Ref. [31]. Its central feature is a superconducting solenoid providing an axial magnetic field of 3.8 T. The bore of the solenoid is instrumented with several particle detection systems. Charged particle trajectories are measured by a silicon pixel and strip tracker system, with full azimuth () coverage and a pseudorapidity () acceptance from À2:5 to þ2:5. Here, À ln½tanð=2Þ and is the polar angle with respect to the counterclockwise beam direction. A lead tungstate crystal electromagnetic calorimeter (ECAL) and a brass or scintillator hadron calorimeter surround the tracking volume and provide coverage in from À3 to þ3. The forward hadron calorimeter extends symmetrically the coverage by a further two units in . Muons are identified in gas ionization detectors embedded in the steel return yoke of the magnet. The CMS detector is nearly hermetic, which allows for momentum-balance measurements in the plane transverse to the beam axis.

An inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of 8 TeV. The data sample corresponds to an integrated luminosity of 11.7 fb−1 collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, αT, is used to discriminate between events with genuine and misreconstructed missing transverse energy. The search is based on an examination of the number of reconstructed jets per event, the scalar sum of transverse energies of these jets, and the number of these jets identified as originating from bottom quarks. No significant excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of simplified models, with a special emphasis on both compressed-spectrum scenarios and direct or gluino-induced production of third-generation squarks. For the case of gluino-mediated squark production, gluino masses up to 950–1125 GeV are excluded depending on the assumed model. For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600 GeV for bottom squarks.