QCD Corrections to Higgs Pair Production in Bottom Quark Fusion

We present a complete next-to-leading order (NLO) calculation for the total cross section of inclusive Higgs pair production via bottom-quark fusion (b{bar b} {yields} hh) at the CERN Large Hadron Collider (LHC) in the Standard Model. The NLO QCD corrections lead to less dependence on the renormalization scale ({mu}{sub R}) and the factorization scale ({mu}{sub F}) than the leading-order (LO) cross section, and they significantly increase the LO cross section. The rate for inclusive Higgs pair production is small in the Standard Model, but can be large in models with enhanced couplings of the b quark to the Higgs bosons

DZero data-intensive computing on the Open Science Grid

High energy physics experiments periodically reprocess data, in order to take advantage of improved understanding of the detector and the data processing code. Between February and May 2007, the DZero experiment has reprocessed a substantial fraction of its dataset. This consists of half a billion events, corresponding to about 100 TB of data, organized in 300,000 files. The activity utilized resources from sites around the world, including a dozen sites participating to the Open Science Grid consortium (OSG). About 1,500 jobs were run every day across the OSG, consuming and producing hundreds of Gigabytes of data. Access to OSG computing and storage resources was coordinated by the SAM-Grid system. This system organized job access to a complex topology of data queues and job scheduling to clusters, using a SAM-Grid to OSG job forwarding infrastructure. For the first time in the lifetime of the experiment, a data intensive production activity was managed on a general purpose grid, such as OSG. This paper describes the implications of using OSG, where all resources are granted following an opportunistic model, the challenges of operating a data intensive activity over such large computing infrastructure, and the lessons learned throughout the project

Physicians Charged with Opioid-Analgesic Prescribing Offenses

Word counts: abstract = 249 , text = 4,329 ABSTRACT Objective. To provide a "big-picture" overview of the characteristics and outcomes of recent criminal and administrative cases in which physicians have been criminally prosecuted or charged by medical boards with offenses related to inappropriate prescribing of opioid analgesics. Design: We identified as many criminal and administrative cases of these types as possible that occurred between 1998 and 2006. Cases were identified using a wide variety of sources, including organizational and government-agency databases, published news accounts, and Websites. Factual characteristics of these cases and their outcomes, and of the physicians involved, then were further researched using additional sources and methods. Setting: Study findings are intended to apply to practicing U.S. patient care physicians as a whole. Patients or other participants: There were no patients or participants in this study. Outcome measures: We analyzed the numbers and types of cases and physicians involved, criminal and administrative charges brought, case outcomes and sanctions, specialties and other characteristics of the physicians involved. Results: The study identified 725 doctors, representing an estimated 0.1% of practicing patient care physicians, who were charged between 1998 and 2006 with criminal and/or administrative offenses related to prescribing opioid analgesics. A plurality of these (39.3%) were General Practice/Family Medicine physicians, compared with 3.5% who were self-identified or board-certified pain specialists. Physicians in this sample were more likely to be male, older, and not board certified (P<0.001). DEA criminal and complaint investigations averaged 658 per year (2003)(2004)(2005)(2006) and "for cause" surrenders of DEA registrations averaged 369.7 (2000-2006). Conclusions: Criminal or administrative charges and sanctions for prescribing opioid analgesics are rare. In addition, there appears to be little objective basis for concern that pain specialists have been "singled out" for prosecution or administrative sanctioning for such offenses

In-Plane Deformation Mechanics for Highly Stretchable Electronics

Scissoring in thick bars suppresses buckling behavior in serpentine traces that have thicknesses greater than their widths, as detailed in a systematic set of analytical and experimental studies. Scissoring in thick copper traces enables elastic stretchability as large as approximate to 350%, corresponding to a sixfold improvement over previously reported values for thin geometries (approximate to 60%).</p

Measurements of top quark pair production cross section in proton anti-proton collisions at s**(1/2) = 1.96 TeV in the tau + jets final state using 1 inv fb of data

This dissertation presents a new measurement of p{bar p} {yields} t{bar t}X production at {radical}s = 1.96 TeV using 974.2 pb{sup -1} of data collected with the D0 detector between 2002 and 2006. We focus on the final state where the W boson from one of the top quarks decays into a {tau} lepton and its associated neutrino, while the other W boson decays into a quark-antiquark pair. We aim to select those events in which the {tau} lepton subsequently decays hadronically, meaning to one or three charged hadrons, zero or more neutral hadrons and a tau neutrino (the charge conjugate processes are implied in all of the above). The observable signature thus consists of a narrow calorimeter shower with associated track(s) characteristic of a hadronic tau decay, four or more jets, of which two are initiated by b quarks accompanying the W's in the top quark decays, and a large net missing momentum in the transverse plane due to the energetic neutrino-antineutrino pair that leave no trace in the detector media. The preliminary result for the measured cross section is: {sigma}(t{bar t}) = 6.9{sub -1.2}{sup +1.2}(stat){sub -0.7}{sup +0.8}(syst) {+-} 0.4 (lumi) pb. This indicates that our finding is consistent with the Standard Model prediction

Recent B physics results from D0

The D0 detector as collected over 3.7 fb{sup -1} of high quality data. With this large data set, D0 is able to perform a number of precision B lifetime and CP asymmetry measurements. Additionally D0 is measuring a number of properties of B hadrons (B{sub s} and B{sub c}) which are currently only accessible at the Tevatron