118457696
Search for new physics in the multijet and missing transverse momentum final state in proton-proton collisions at $ \sqrt{s} $ = 8 TeV
A bstractA search for new physics is performed in multijet events with large missing transverse momentum produced in proton-proton collisions at $ \sqrt{s} $ = 8 TeV using a data sample corresponding to an integrated luminosity of 19.5 fb−1 collected with the CMS detector at the LHC. The data sample is divided into three jet multiplicity categories (3-5, 6-7, and ≥8 jets), and studied further in bins of two variables: the scalar sum of jet transverse momenta and the missing transverse momentum. The observed numbers of events in various categories are consistent with backgrounds expected from standard model processes. Exclusion limits are presented for several simplified supersymmetric models of squark or gluino pair production.

119294066
High-$p_T$ triggered dihadron correlations with $v_n$ background subtraction by STAR
STAR measurements of dihadron correlations with high-pt trigger partcles in Au+Au collisions at 200 GeV are presented with subtraction of v2, v3, and v4 backgrounds. The vn azimuthal anisotropies were measured by the two-particle cumulant method with \eta\ gap to reduce nonflow. The dihadron correlations relative to the v2 as well as the v3 harmonic planes are also presented. Implications of the results are discussed.
13043536
Cumulant versus jet-like three-particle correlations
Two-particle jet-like azimuthal correlations have revealed intriguing modifications to the away-side of high p{sub perpendicular} trigger particles in relativistic heavy-ion collisions. Three-particle jet-like azimuthal correlation and three-particle azimuthal cumulant have been analyzed in experiments in attempt to distinguish conical emission of jet-correlated particles from other physics mechanisms. We investigate the difference between three-particle jet-like correlation and three-particle cumulant in azimuth. We show, under the circumstance where the away-side two-particle correlation is relatively flat in azimuth and similar in magnitude to the azimuthal average of the two-particle correlation signal, that the three-particle cumulant cannot distinguish conical emission from other physics mechanisms. The three-particle jet-like correlation, on the other hand, retains its discrimination power.
118143933
Effects of nuclear absorption on the antiLambda/antiproton ratio in relativistic heavy ion collisions
An enhanced antiLambda/antiproton ratio in heavy-ion relative to p+p collisions has been proposed as one of the signatures for the Quark-Gluon Plasma (QGP) formation. A significantly large (antiLambda+antiSigma0+1.1*antiSigma-)/antiproton ratio of 3.5 has been observed in the mid-rapidity and low transverse momentum region in central Au+Au collisions at the nucleon-nucleon center-of-mass energy of 4.9 GeV at the Alternating Gradient Synchrotron (AGS). This is an order of magnitude larger than the values in peripheral Au+Au collisions and p+p collisions at the corresponding energy. By using the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) transport model, we demonstrate that the observed large ratio can be explained by strong absorption of antiprotons (~99.9%) and antiLambdas (~99%) in dense nuclear matter created in central collisions. We find within the model that the initial antiLambda/antiproton ratio, mainly from string fragmentation, does not depend on the collision centrality, and is consistent with that observed in p+p collisions. This suggests that the observed large (antiLambda+antiSigma0+1.1*antiSigma-)/antiproton ratio at the AGS does not necessarily imply the formation of the QGP. We further study the excitation function of the ratio in UrQMD, which may help in the search and study of the QGP.
14237956
Analysis method for jet-like three-particle azimuthal correlations
Jet-like three-particle azimuthal correlations can discriminate various physical scenarios that have been proposed to explain the observed strong modification to two-particle azimuthal correlations. The three-particle correlation analysis is notoriously difficult in heavy-ion collisions due to the large combinatorial backgrounds. We describe the general idea behind the jet-like three-particle azimuthal correlation analysis, with emphasis on the subtraction of the combinatorial backgrounds. We discuss in detail various sources of systematic uncertainties in such an analysis.
36928550
Effects of cluster particle correlations on local parity violation observables
We investigate effects of cluster particle correlations on two- and three-particle azimuth correlator observables sensitive to local strong parity violation. We use two-particle angular correlation measurements as inputs and estimate the magnitudes of the effects with straightforward assumptions. We found that the measurements of the azimuth correlator observables in the STAR experiment can be entirely accounted for by cluster particle correlations together with a reasonable range of cluster anisotropy in nonperipheral collisions. Our result suggests that new physics, such as local strong parity violation, may not be required to explain the correlator data.
123566403
Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using 4.7 fb-1 of √s = 7 TeV proton-proton collision data
A search for squarks and gluinos in final states containing jets, missing transverse momentum and no high-p(T) electrons or muons is presented. The data represent the complete sample recorded in 2011 by the ATLAS experiment in 7 TeV proton-proton collisions at the Large Hadron Collider, with a total integrated luminosity of 4.7 fb(-1). No excess above the Standard Model background expectation is observed. Gluino masses below 860 GeV and squark masses below 1320 GeV are excluded at the 95% confidence level in simplified models containing only squarks of the first two generations, a gluino octet and a massless neutralino, for squark or gluino masses below 2 TeV, respectively. Squarks and gluinos with equal masses below 1410 GeV are excluded. In minimal supergravity/constrained minimal supersymmetric Standard Model models with tan beta = 10, A(0) = 0 and mu > 0, squarks and gluinos of equal mass are excluded for masses below 1360 GeV. Constraints are also placed on the parameter space of supersymmetric models with compressed spectra. These limits considerably extend the region of supersymmetric parameter space excluded by previous measurements with the ATLAS detector.
2929705
Wakefield measurements of SLAC linac structures at the Argonne AATF
Results are presented of measurements of both longitudinal and transverse wakefields performed at the Argonne National Laboratory Advanced Accelerator Test Facility with two SLAC-built X-band disk-loaded waveguides: a conventional 30-cavity long constant-impedance structure and a nonconventional 50-cavity long structure along which the iris and spacer diameters have been varied so as to stagger-tune the HEM/sub 11/ mode frequency by 37%. The results are shown to be in excellent agreement with computations made by KN7C, TRANSVRS, TBCI, and LINACBBU.<<ETX>>
17545140
First observation of the sigma(*+)(c) baryon and a new measurement of the sigma(*+)(c) mass.
Using data recorded with the CLEO II and CLEO II.V detector configurations at the Cornell Electron Storage Rings, we report the first observation and mass measurement of the Sigma(*+)(c) charmed baryon, and an updated measurement of the mass of the Sigma(+)(c) baryon. We find M(Sigma(*+)(c))-M(Lambda(+)(c)) = (231.0+/-1.1+/-2.0) MeV, and M(Sigma(+)(c))-M(Lambda(+)(c)) = (166.4+/-0.2+/-0.3) MeV, where the errors are statistical and systematic, respectively.
124472455
Search for diphoton events with large missing transverse momentum in 7 TeV proton-proton collision data with the ATLAS detector
A search for diphoton events with large missing transverse momentum has been performed using proton-proton collision data at is root s = 7 TeV recorded with the ATLAS detector, corresponding to an integrated luminosity of 4.8 fb(-1). No excess of events was observed above the Standard Model prediction and model-dependent 95% confidence level exclusion limits are set. In the context of a generalised model of gauge-mediated supersymmetry breaking with a bino-like lightest neutralino of mass above 50 GeV, gluinos (squarks) below 1.07 TeV (0.87 TeV) are excluded, while a breaking scale Lambda below 196 TeV is excluded for a minimal model of gauge-mediated supersymmetry breaking. For a specific model with one universal extra dimension, compactification scales 1/R < 1.40 TeV are excluded. These limits provide the most stringent tests of these models to date. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.
30236486
Observation of the Omega(0)(c) Charmed Baryon at CLEO.
The CLEO experiment at the CESR collider has used 13.7 fb(-1) of data to search for the production of the Omega(0)(c) (css ground state) in e(+)e(-) collisions at square root of (s) approximately 10.6 GeV. The modes used to study the Omega(0)(c) are Omega(-)pi(+), Omega(-)pi(+)pi(0), Xi-K-pi(+)pi(+), Xi0K-pi(+), and Omega(-)pi(+)pi(+)pi(-). We observe a signal of 40.4+/-9.0(stat) events at a mass of 2694.6+/-2.6(stat)+/-1.9(syst) MeV/c(2), for all modes combined.