Information and Communication Technology Assessment Benchmark

This paper reports on an initial effort to assess student learning with respect to effective use of information and communication technology. A business school in a small public university administered the iSkills assessment from the Educational Testing Service (ETS) in 2008. This online web service simulates websites, web searches, databases, and office productivity software to present realistic scenarios. iSkills evaluates seven skill areas (define, access, evaluate, manage, integrate, create, and communicate). Upper division student median performance on the Advanced Level test was generally above the median level of the reference group with strengths in the Define and Integrate proficiencies and weaknesses in the Manage and Create proficiencies. Lower division student median performance on the Advanced Level test was generally below the median with strengths in the Access and the Integrate proficiencies and weaknesses in the Manage, Define, and Communicate proficiencies. Lower division student median performance on the Core Level test was generally below the median with strengths in the Access and Integrate proficiencies and weaknesses in the Evaluate and Communicate proficiencies. While the upper division students performed adequately, there remains room for improvement. The lower division student performance will provide a benchmark to measure the impact of planned curriculum changes

New limits for neutrinoless tau decays

Neutrinoless 3-prong tau lepton decays into a charged lepton and either two charged particles or one neutral meson have been searched for using 4.79fb^(-1) of data collected with the CLEO II detector at Cornell Electron Storage Ring. This analysis represents an update of a previous study and the addition of six decay channels. In all channels the numbers of events found are compatible with background estimates and branching fraction upper limits are set for 28 different decay modes. These limits are either more stringent than those set previously or represent the first attempt to find these decays

Search for right-handed W bosons in top quark decay

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.72.011104.We present a measurement of the fraction f(+) of right-handed W bosons produced in top quark decays, based on a candidate sample of tt-bar events in the lepton+jets decay mode. These data correspond to an integrated luminosity of 230  pb(−1), collected by the D0 detector at the Fermilab Tevatron pp-bar Collider at s√=1.96  TeV. We use a constrained fit to reconstruct the kinematics of the tt-bar and decay products, which allows for the measurement of the leptonic decay angle θ∗ for each event. By comparing the cosθ∗ distribution from the data with those for the expected background and signal for various values of f(+), we find f(+(=0.00±0.13(stat)±0.07(syst). This measurement is consistent with the standard model prediction of f(+)=3.6×10(−4)

Measurement of the angular distribution of electrons from W⃗ eν decays observed in pp-bar collisions at s√=1.8 TeV

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.63.072001.We present the first measurement of the electron angular distribution parameter α(2) in W⃗ eν events produced in proton-antiproton collisions as a function of the W boson transverse momentum. Our analysis is based on data collected using the DØ detector during the 1994–1995 Fermilab Tevatron run. We compare our results with next-to-leading order perturbative QCD, which predicts an angular distribution of (1±α(1c)osθ*+α(2)cos(2)θ*), where θ* is the polar angle of the electron in the Collins-Soper frame. In the presence of QCD corrections, the parameters α(1) and α(2) become functions of pWT, the W boson transverse momentum. This measurement provides a test of next-to-leading order QCD corrections which are a non-negligible contribution to the W boson mass measurement

Search for dilepton signatures from minimal low-energy supergravity in pp-bar collisions at s√=1.8 TeV

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.63.091102.We report on a search for supersymmetry using the DØ detector. The 1994–1996 data sample of s√=1.8 TeV pp-bar collisions was analyzed for events containing two leptons (e or μ), two or more jets, and missing transverse energy. Assuming the minimal supergravity model, with A(0)=0 and μ<0, various thresholds were employed to optimize the search. No events were found beyond expectation from the background. We set a lower limit at the 95% C.L. of 255 GeV/c(2) for equal mass squarks and gluinos for tanβ=2, and present exclusion contours in the (m(0),m(1/2)) plane for tanβ=2–6

Hadronic transitions Υ(2S)→Υ(1S)

This is the publisher's version, also available electronically from http://journals.aps.org/prd/abstract/10.1103/PhysRevD.58.052004.Using a 73.6pb(-1) data sample of Υ(2S) events collected with the CLEO II detector at the Cornell Electron Storage Ring, we have investigated the hadronic transitions between the Υ(2S) and the Υ(1S). The dipion transition Υ(2S)→Υ(1S)π(+)π(-) was studied using two different analysis techniques. Selecting events in which Υ(1S)→e(+)e(-),μ(+)μ(-) (“exclusive” analysis), and using the Υ(1S) leptonic branching fractions world averages from the PDG review, we obtained B(Υ(2S)→Υ(1S)π(+)π(-))=0.189±0.004±0.010, while using a method allowing Υ(1S)→anything (“inclusive” analysis) we obtained B(Υ(2S)→Υ(1S)π(+)π(-))=0.196±0.002±0.010. The appropriate weighted average of the two measurements gives B(Υ(2S)→Υ(1S)π(+)π(-))=0.192±0.002±0.010. Combining the exclusive and inclusive results we derive the Υ(1S) leptonic branching fractions Bee=0.0229±0.0008±0.0011 and Bμμ=0.0249±0.0008±0.0013. We also studied Υ(2S)→Υ(1S)π(0)π(0) and obtained B(Υ(2S)→Υ(1S)π(0)π(0))=0.092±0.006±0.008. Parameters of the ππ system (dipion invariant mass spectra, angular distributions) were analyzed and found to be consistent with current theoretical models. Lastly, we searched for the η and single π(0) transitions and obtained the 90% confidence level upper limits B(Υ(2S)→Υ(1S)η)<0.0028 and B(Υ(2S)→Υ(1S)π(0))<0.0011

Direct limits on the B-s(0) oscillation frequency

We report results of a study of the B-s(0) oscillation frequency using a large sample of B-s(0) semileptonic decays corresponding to approximately 1 fb(-1) of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider in 2002-2006. The amplitude method gives a lower limit on the B-s(0) oscillation frequency at 14.8 ps(-1) at the 95% C.L. At Delta m(s)=19 ps(-1), the amplitude deviates from the hypothesis A=0 (1) by 2.5 (1.6) standard deviations, corresponding to a two-sided C.L. of 1% (10%). A likelihood scan over the oscillation frequency, Delta m(s), gives a most probable value of 19 ps(-1) and a range of 17 <Delta m(s)< 21 ps(-1) at the 90% C.L., assuming Gaussian uncertainties. This is the first direct two-sided bound measured by a single experiment. If Delta m(s) lies above 22 ps(-1), then the probability that it would produce a likelihood minimum similar to the one observed in the interval 16-22 ps(-1) is (5.0 +/- 0.3)%

Search for supersymmetry via associated production of charginos and neutralinos in final states with three leptons

A search for associated production of charginos and neutralinos is performed using data recorded with the D0 detector at a p (p) over bar center-of-mass energy of 1.96 TeV at the Fermilab Tevatron Collider. This analysis considers final states with missing transverse energy and three charged leptons, of which at least two are electrons or muons. No evidence for supersymmetry is found in a data set corresponding to an integrated luminosity of 320 pb(-1). Limits on the product of the production cross section and leptonic branching fraction are set. For the minimal supergravity model, a chargino lower mass limit of 117 GeV at the 95% C.L. is derived in regions of parameter space with enhanced leptonic branching fractions

Search for randall-sundrum gravitons in dilepton and diphoton final states

We report the first direct search for the Kaluza-Klein (KK) modes of Randall-Sundrum gravitons using dielectron, dimuon, and diphoton events observed with the D0 detector operating at the Fermilab Tevatron p (p) over bar Collider at root s = 1: 96 TeV. No evidence for resonant production of gravitons has been found in the data corresponding to an integrated luminosity of approximate to 260 pb(-1). Lower limits on the mass of the first KK mode at the 95% C. L. have been set between 250 and 785 GeV, depending on its coupling to standard model particles

Search for resonant second generation slepton production at the Fermilab Tevatron

We present a search for supersymmetry in the R-parity violating resonant production and decay of smuons and muon sneutrinos in the channels mu ->chi(0)(1)mu, mu ->chi(0)(2,3,4)mu, and nu(mu)->chi(+/-)(1,2)mu. We analyzed 0.38 fb(-1) of integrated luminosity collected between April 2002 and August 2004 with the D0 detector at the Fermilab Tevatron Collider. The observed number of events is in agreement with the standard model expectation, and we calculate 95% C.L. limits on the slepton production cross section times branching fraction to gaugino plus muon, as a function of slepton and gaugino masses. In the framework of minimal supergravity, we set limits on the coupling parameter lambda(')(211), extending significantly previous results obtained in Run I of the Tevatron and at the CERN LEP collider