118867968
Production of a Higgs Boson Plus Two Jets in Hadronic Collisions
We consider the production of a Standard Model Higgs boson accompanied by two jets in hadronic collisions. We work in the limit that the top quark is much heavier than the Higgs boson and use an e ective Lagrangian for the interactions of gluons with the Higgs boson. In addition to the previously computed four-gluon process, we compute the the amplitudes involving two quarks, two gluons and the Higgs boson and those involving four quarks and the Higgs boson. We exhibit the form of our results in the small-pH and factorization limits. We present numerical results for p S = 14 TeV and p S = 2 TeV. We nd that the dominant processes are gg ! ggH and qg ! qgH with the former (latter) contributing about 60% (40%) of the cross section at p S = 14 TeV and the two processes each contributing about half the cross section at p S = 2 TeV. All other processes are negligible at both energies. September 1996
125296528
Low-mass Higgs searches at the Tevatron
30114466
Amplitudes for Higgs bosons plus four partons
In this talk we consider amplitudes for processes involving a Higgs boson, either scalar or pseudoscalar, plus four light partons. These amplitudes are relevant to the production of a Higgs boson plus two jets in hadronic collisions. They are also relevant to calculating the transverse momentum spectrum for Higgs bosons at next-to-leading order in the strong coupling. We work in the limit that the top quark is much heavier than the Higgs bosons and use effective Lagrangians for the interactions of gluons with the Higgs bosons. We present the amplitudes involving a Higgs boson and: 1) four gluons, 2) two quarks and two gluons; and 3) four quarks. We show that the pseudoscalar amplitudes are nearly identical to those for the scalar case, the only differences being the overall size and the relative signs between terms.
113469755
Radiation Damage Study of the D0 Silicon Microstrip Tracker
The Run II DØ experiment at the Fermilab Tevatron collider ha s been operating since 2001. At the heart of the DØ tracking system is a silicon microstrip de tector. It is built from four layers of single sided and double sided sensors organized in six bar rels, and two sets of seven disks. An additional, very small radius layer of silicon sensors, c onsisting of eight barrels, was inserted during the spring of 2006. We monitor the silicon sensors for radiation damage. A bulk c arrier-type reversal was observed in the innermost layer of the original detector after 1.5 fb −1 of integrated luminosity. We present the results of aging studies and predictions for lifetime of the detector for the rest of Run II at the Tevatron.
16162456
Production of a Higgs pseudoscalar plus two jets in hadronic collisions
We consider the production of a Higgs pseudoscalar accompanied by two jets in hadronic collisions. We work in the limit that the top quark is much heavier than the Higgs pseudoscalar and use an effective Lagrangian for the interactions of gluons with the pseudoscalar. We compute the amplitudes involving: 1) four gluons and the pseudoscalar, 2) two quarks, two gluons and the pseudoscalar and 3) four quarks and the pseudoscalar. We find that the pseudoscalar amplitudes are nearly identical to those for the scalar case, the only differences being the overall size and the relative signs between terms. We present numerical cross sections for proton-proton collisions with center-of-mass energy 14 TeV.
117749606
Baryon content of massive galaxy clusters at 0.57 < z < 1.33
We study the stellar, brightest cluster galaxy (BCG) and intracluster medium (ICM) masses of 14 South Pole Telescope (SPT) selected galaxy clusters with median redshift z = 0.9 and mass M-500 = 6 x 10(14) M-circle dot. We estimate stellar masses for each cluster and BCG using six photometric bands, the ICM mass using X-ray observations and the virial masses using the SPT Sunyaev-Zel'dovich effect signature. At z = 0.9, the BCG mass M-*(BCG) constitutes 0.12 +/- 0.01 per cent of the halo mass for a 6 x 10(14) M-circle dot cluster, and this fraction falls as M-500(-0.58 +/- 0.07). The cluster stellar mass function has a characteristic mass M-0 = 10(11.0 +/- 0.1) M-circle dot, and the number of galaxies per unit mass in clusters is larger than in the field by a factor of 1.65 +/- 0.20. We combine our SPT sample with previously published samples at low redshift and correct to a common initial mass function and for systematic virial mass differences. We then explore mass and redshift trends in the stellar fraction f(*), the ICM fraction f(ICM), the collapsed baryon fraction f(c) and the baryon fraction f(b). At a pivot mass of 6 x 10(14) M-circle dot and redshift z = 0.9, the characteristic values are f(*) = 1.1 +/- 0.1 per cent, f(ICM) = 9.6 +/- 0.5 per cent, f(c) = 10.7 +/- 1.1 per cent and f(b) = 10.7 +/- 0.6 per cent. These fractions all vary with cluster mass at high significance, with higher mass clusters having lower f(*) and f(c) and higher f(ICM) and f(b). When accounting for a 15 per cent systematic virial mass uncertainty, there is no statistically significant redshift trend at fixed mass. Our results support the scenario where clusters grow through accretion from subclusters (higher f(*), lower f(ICM)) and the field (lower f(*), higher f(ICM)), balancing to keep f(*) and f(ICM) approximately constant since z similar to 0.9.
13992842
Proposed method for searches of gravitational waves from PKS 2155-304 and other blazar flares
We propose to search for gravitational waves from PKS 2155-304 as well as other blazars. PKS 2155-304 emitted a long-duration energetic flare in July 2006 with total isotropic equivalent energy released in TeV gamma rays of approximately 1045 ergs. Possible gravitational wave signals associated with this outburst are expected to be seen at the same time as the electromagnetic signal. During this flare, the two LIGO interferometers at Hanford and the GEO detector were in operation and collecting data. For this search we will use the data from multiple gravitational wave detectors. The method we use for this purpose is a coherent network analysis algorithm which is called RIDGE. To estimate the sensitivity of the search, we perform numerical simulations. For a detection probability of 20%, we estimate that this method is sensitive to total isotropic equivalent energy at the source of about 2.5 × 1055 ergs. For this analysis, an end-to-end pipeline has been developed, which takes into account the motion of the source across the sky.
119295671
The Blanco Cosmology Survey: Data Acquisition, Processing, Calibration, Quality Diagnostics and Data Release
The Blanco Cosmology Survey (BCS) is a 60 night imaging survey of ~80 deg2 of the southern sky located in two fields: (α, δ) = (5 hr, –55°) and (23 hr, –55°). The survey was carried out between 2005 and 2008 in griz bands with the Mosaic2 imager on the Blanco 4 m telescope. The primary aim of the BCS survey is to provide the data required to optically confirm and measure photometric redshifts for Sunyaev-Zel'dovich effect selected galaxy clusters from the South Pole Telescope and the Atacama Cosmology Telescope. We process and calibrate the BCS data, carrying out point-spread function-corrected model-fitting photometry for all detected objects. The median 10σ galaxy (point-source) depths over the survey in griz are approximately 23.3 (23.9), 23.4 (24.0), 23.0 (23.6), and 21.3 (22.1), respectively. The astrometric accuracy relative to the USNO-B survey is ~45 mas. We calibrate our absolute photometry using the stellar locus in grizJ bands, and thus our absolute photometric scale derives from the Two Micron All Sky Survey, which has ~2% accuracy. The scatter of stars about the stellar locus indicates a systematic floor in the relative stellar photometric scatter in griz that is ~1.9%, ~2.2%, ~2.7%, and ~2.7%, respectively. A simple cut in the AstrOmatic star-galaxy classifier spread_model produces a star sample with good spatial uniformity. We use the resulting photometric catalogs to calibrate photometric redshifts for the survey and demonstrate scatter δz/(1 + z) = 0.054 with an outlier fraction η < 5% to z ~ 1. We highlight some selected science results to date and provide a full description of the released data products.
21908658
Study of Upward Showering Muons in Super-Kamiokande
A small subset of neutrino-induced upward going muons in the SuperKamiokande detector consists of high energy muons that undergo radiative energy losses through bremsstrahlung, pair production and photo-nuclear interactions. The mean energy of the parent neutrinos of these showering upward muons is approximately 1 TeV, allowing the selection of a high energy sample of neutrinos. We present the energy spectrum of the parent neutrinos of these upward showering muons and results based on searches for WIMP-induced neutrinos using these upward showering muons are presented.
324538
Constraints on the CMB temperature evolution using multiband measurements of the Sunyaev–Zel'dovich effect with the South Pole Telescope
The adiabatic evolution of the temperature of the cosmic microwave background (CMB) is a key prediction of standard cosmology. We study deviations from the expected adiabatic evolution of the CMB temperature of the form T(z) = T_0(1 + z)^(1 − α) using measurements of the spectrum of the Sunyaev–Zel'dovich effect with the South Pole Telescope (SPT). We present a method for using the ratio of the Sunyaev–Zel'dovich signal measured at 95 and 150 GHz in the SPT data to constrain the temperature of the CMB. We demonstrate that this approach provides unbiased results using mock observations of clusters from a new set of hydrodynamical simulations. We apply this method to a sample of 158 SPT-selected clusters, spanning the redshift range 0.05 < z < 1.35, and measure α=0.017^(+0.030)_(−0.028), consistent with the standard model prediction of α = 0. In combination with other published results, we find α = 0.005 ± 0.012, an improvement of ∼10 per cent over published constraints. This measurement also provides a strong constraint on the effective equation of state in models of decaying dark energy w_(eff) = −0.994 ± 0.010.