The K-band Hubble diagram of submillimetre galaxies and hyperluminous galaxies
Monthly Notices of the Royal Astronomical Society 346:4 (2003)
Abstract:
We present the K-baad Hubble diagrams (K-z relations) of submillimetre-selected galaxies and hyperluminous galaxies (HLIRGs). We report the discovery of a remarkably tight K-z relation of HLIRGs, indistinguishable from that of the most luminous radio galaxies. Like radio galaxies, the HLIRG K-z relation at z ∼ 3 is consistent with a passively evolving ∼3L* instantaneous starburst starting from a redshift of z ∼ 10. In contrast, many submillimetre-selected galaxies are ≳2 mag fainter, and the population has a much larger dispersion. We argue that dust obscuration and/or a larger mass range may be responsible for this scatter. The galaxies so far proved to be hyperluminous may have been biased towards higher AGN bolometric contributions than submillimetre-selected galaxies due to the 60-μm selection of some, so the location on the K-z relation may be related to the presence of the most massive active galactic nucleus. Alternatively, a particular host galaxy mass range may be responsible for both extreme star formation and the most massive active nuclei.Measurement of prompt charm meson production cross sections in p p̄ collisions at √s = 1.96 TeV
Physical Review Letters 91:24 (2003)
Abstract:
Differential cross sections dσ/dPT for prompt charm meson production in pp̄ collisions at √s=1.96 TeV were measured. The measured differential cross sections are higher than the theoretical predictions by about 100% at low pT and 50% at high pT. However, they are compatible within uncertainties. The models also underestimate Β meson productions at √s=1.8 TeV by similar factors [2,4,5].An aging study of industrially produced micro-patterned gas detectors
IEEE Nuclear Science Symposium Conference Record 5 (2003) 3723-3725
Abstract:
Micropatterned gas detectors like GEMs and MICROMEGAS are being considered for time projection chambers (TPC) for linear collider experiments. These devices are made mainly of Kapton insulators and thick copper layers. Because in the micropatterned gas detectors a dense plasma of avalanche electrons and ions are created in a small volume, aging due to polymerization is a concern. A shot-term aging study on a single GEM foil produced by 3M using reel-to-reel flex circuit technology is reported.Measurement of the mass difference m(Ds +)-m(D +) at CDF II
Physical Review D 68:7 (2003)