The Milky Way Project: A statistical study of massive star formation associated with infrared bubbles
ArXiv 1203.5486 (2012)
Abstract:
The Milky Way Project citizen science initiative recently increased the number of known infrared bubbles in the inner Galactic plane by an order of magnitude compared to previous studies. We present a detailed statistical analysis of this dataset with the Red MSX Source catalog of massive young stellar sources to investigate the association of these bubbles with massive star formation. We particularly address the question of massive triggered star formation near infrared bubbles. We find a strong positional correlation of massive young stellar objects (MYSOs) and H II regions with Milky Way Project bubbles at separations of < 2 bubble radii. As bubble sizes increase, a statistically significant overdensity of massive young sources emerges in the region of the bubble rims, possibly indicating the occurrence of triggered star formation. Based on numbers of bubble-associated RMS sources we find that 67+/-3% of MYSOs and (ultra)compact H II regions appear associated with a bubble. We estimate that approximately 22+/-2% of massive young stars may have formed as a result of feedback from expanding H II regions. Using MYSO-bubble correlations, we serendipitously recovered the location of the recently discovered massive cluster Mercer 81, suggesting the potential of such analyses for discovery of heavily extincted distant clusters.Measurement of the W ±Z production cross section and limits on anomalous triple gauge couplings in proton-proton collisions at s=7 TeV with the ATLAS detector
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 709:4-5 (2012) 341-357
Abstract:
This Letter presents a measurement of W ±Z production in 1.02 fb -1 of pp collision data at s=7 TeV collected by the ATLAS experiment in 2011. Doubly leptonic decay events are selected with electrons, muons and missing transverse momentum in the final state. In total 71 candidates are observed, with a background expectation of 12.1±1.4(stat.)-2.0+4.1(syst.) events. The total cross section for W ±Z production for Z/γ * masses within the range 66 GeV to 116 GeV is determined to be σWZtot=20.5-2.8+3.1(stat.)-1.3+1.4(syst.)-0.8+0.9(lumi.) pb, which is consistent with the Standard Model expectation of 17.30.8+1.3 pb. Limits on anomalous triple gauge boson couplings are extracted. © 2012 CERN.Search for strong gravity signatures in same-sign dimuon final states using the ATLAS detector at the LHC
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics 709:4-5 (2012) 322-340
Abstract:
A search for microscopic black holes has been performed in a same-sign dimuon final state using 1.3 fb -1 of proton-proton collision data collected with the ATLAS detector at a centre of mass energy of 7 TeV at the CERN Large Hadron Collider. The data are found to be consistent with the expectation from the Standard Model and the results are used to derive exclusion contours in the context of a low scale gravity model. © 2012 CERN.Measurement of the inclusive jet cross section in pp̄ collisions at √s=1.96TeV
Physical Review D - Particles, Fields, Gravitation and Cosmology 85:5 (2012)
Abstract:
We present a measurement of the inclusive jet cross section using the Run II cone algorithm and data collected by the D0 experiment in pp̄ collisions at a center-of-mass energy √s=1.96TeV, corresponding to an integrated luminosity of 0.70fb -1. The jet energy calibration and the method used to extract the inclusive jet cross section are described. We discuss the main uncertainties, which are dominated by the jet energy scale uncertainty. The results cover jet transverse momenta from 50GeV to 600GeV with jet rapidities in the range -2.4 to 2.4 and are compared to predictions using recent proton parton distribution functions. Studies of correlations between systematic uncertainties in transverse momentum and rapidity are presented. © 2012 American Physical Society.Assessing luminosity correlations via cluster analysis: Evidence for dual tracks in the radio/X-ray domain of black hole X-ray binaries
(2012)