21 research outputs found

    Probing quark gluon plasma with jets

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    We study multiple scatterings of jets on constituents of quark gluon plasma and introduce energy--energy correlations to quantify their effects. The effects from a longitudinally expanding plasma on medium as well as high energy jets are found to be significant at both RHIC and LHC energies. Because jets escape from the plasma long before the completion of mixed phase, these effects are free from complications of final state hadronic interactions and decays. These suggest that jets can be used to probe the plasma that might be created in future high energy heavy ion collisions.Comment: 15 pages, 6 figures in 5 ps files included, McGill/94-1

    A Measurement of Psi(2S) Resonance Parameters

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    Cross sections for e+e- to hadons, pi+pi- J/Psi, and mu+mu- have been measured in the vicinity of the Psi(2S) resonance using the BESII detector operated at the BEPC. The Psi(2S) total width; partial widths to hadrons, pi+pi- J/Psi, muons; and corresponding branching fractions have been determined to be Gamma(total)= (264+-27) keV; Gamma(hadron)= (258+-26) keV, Gamma(mu)= (2.44+-0.21) keV, and Gamma(pi+pi- J/Psi)= (85+-8.7) keV; and Br(hadron)= (97.79+-0.15)%, Br(pi+pi- J/Psi)= (32+-1.4)%, Br(mu)= (0.93+-0.08)%, respectively.Comment: 8 pages, 6 figure

    On kinematical constraints in boson-boson systems

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    We consider the scattering of two-bosons with negative parity and spin 0 or 1. Starting from helicity partial-wave scattering amplitudes we derive transformations that eliminate all kinematical constraints. Such amplitudes are expected to satisfy partial-wave dispersion relations and therefore provide a suitable basis for data analysis and the construction of effective field theories. Our derivation relies on a decomposition of the various scattering amplitudes into suitable sets of invariant functions. A novel algebra was developed that permits the efficient computation of such functions in terms of computer algebra codes.Comment: 14 pages, 8 table

    Viral clearance, pharmacokinetics and tolerability of ensovibep in patients with mild to moderate COVID-19: a phase 2a, open-label, single-dose escalation study

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    AimTo assess viral clearance, pharmacokinetics, tolerability and symptom evolution following ensovibep administration in symptomatic COVID-19 outpatients.MethodsIn this open-label, first-in-patient study a single dose of either 225 mg (n = 6) or 600 mg (n = 6) of ensovibep was administered intravenously in outpatients with mild-to-moderate COVID-19 symptoms. Pharmacokinetic profiles were determined (90-day period). Pharmacodynamic assessments consisted of viral load (qPCR and cultures) and symptom questionnaires. Immunogenicity against ensovibep and SARS-CoV-2-neutralizing activity were determined. Safety and tolerability were assessed throughout a 13-week follow-up.ResultsBoth doses showed similar pharmacokinetics (first-order) with mean half-lives of 14 (SD 5.0) and 13 days (SD 5.7) for the 225- and 600-mg groups, respectively. Pharmacologically relevant serum concentrations were maintained in all subjects for at least 2 weeks postdose, regardless of possible immunogenicity against ensovibep. Viral load changes from baseline at day 15 were 5.1 (SD 0.86) and 5.3 (SD 2.2) log10 copies/mL for the 225- and 600-mg doses, respectively. COVID-19 symptom scores decreased from 10.0 (SD 4.1) and 11.3 (SD 4.0) to 1.6 (SD 3.1) and 3.3 (SD 2.4) in the first week for the 225- and 600-mg groups, respectively. No anti-SARS-CoV-2 neutralizing activity was present predose and all patients had SARS-CoV-2 antibodies at day 91. Adverse events were of mild-to-moderate severity, transient and self-limiting.ConclusionSingle-dose intravenous administration of 225 or 600 mg of ensovibep appeared safe and well tolerated in patients with mild-to-moderate COVID-19. Ensovibep showed favourable pharmacokinetics in patients and the pharmacodynamic results warrant further research in a larger phase 2/3 randomized-controlled trail.Perioperative Medicine: Efficacy, Safety and Outcome (Anesthesiology/Intensive Care

    Time-integrated luminosity recorded by the BABAR detector at the PEP-II e+e- collider

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    This article is the Preprint version of the final published artcile which can be accessed at the link below.We describe a measurement of the time-integrated luminosity of the data collected by the BABAR experiment at the PEP-II asymmetric-energy e+e- collider at the ϒ(4S), ϒ(3S), and ϒ(2S) resonances and in a continuum region below each resonance. We measure the time-integrated luminosity by counting e+e-→e+e- and (for the ϒ(4S) only) e+e-→μ+μ- candidate events, allowing additional photons in the final state. We use data-corrected simulation to determine the cross-sections and reconstruction efficiencies for these processes, as well as the major backgrounds. Due to the large cross-sections of e+e-→e+e- and e+e-→μ+μ-, the statistical uncertainties of the measurement are substantially smaller than the systematic uncertainties. The dominant systematic uncertainties are due to observed differences between data and simulation, as well as uncertainties on the cross-sections. For data collected on the ϒ(3S) and ϒ(2S) resonances, an additional uncertainty arises due to ϒ→e+e-X background. For data collected off the ϒ resonances, we estimate an additional uncertainty due to time dependent efficiency variations, which can affect the short off-resonance runs. The relative uncertainties on the luminosities of the on-resonance (off-resonance) samples are 0.43% (0.43%) for the ϒ(4S), 0.58% (0.72%) for the ϒ(3S), and 0.68% (0.88%) for the ϒ(2S).This work is supported by the US Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l’Energie Atomique and Institut National de Physique Nucléaire et de Physiquedes Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovación (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie-Curie IEF program (European Union) and the A.P. Sloan Foundation (USA)

    Measurements of the cross sections for e+ehadronse^+e^- \to {\rm hadrons} at 3.650, 3.6648, 3.773 GeV and the branching fraction for ψ(3770)nonDDˉ\psi(3770)\to {\rm non-}D\bar D

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    Using the BES-II detector at the BEPC Collider, we measured the lowest order cross sections and the RR values (R=σe+ehadrons0/σe+eμ+μ0R=\sigma^0_{e^+e^- \to {\rm hadrons}}/\sigma^0_{e^+e^- \to \mu^+\mu^-}) for inclusive hadronic event production at the center-of-mass energies of 3.650 GeV, 3.6648 GeV and 3.773 GeV. The results lead to Rˉuds=2.224±0.019±0.089\bar R_{uds}=2.224\pm 0.019\pm 0.089 which is the average of these measured at 3.650 GeV and 3.6648 GeV, and R=3.793±0.037±0.190R=3.793\pm 0.037 \pm 0.190 at s=3.773\sqrt{s}=3.773 GeV. We determined the lowest order cross section for ψ(3770)\psi(3770) production to be σψ(3770)B=(9.575±0.256±0.813) nb\sigma^{\rm B}_{\psi(3770)} = (9.575\pm 0.256 \pm 0.813)~{\rm nb} at 3.773 GeV, the branching fractions for ψ(3770)\psi(3770) decays to be BF(ψ(3770)D0Dˉ0)=(48.9±1.2±3.8)BF(\psi(3770) \to D^0\bar D^0)=(48.9 \pm 1.2 \pm 3.8)%, BF(ψ(3770)D+D)=(35.0±1.1±3.3)BF(\psi(3770) \to D^+ D^-)=(35.0 \pm 1.1 \pm 3.3)% and BF(ψ(3770)DDˉ)=(83.9±1.6±5.7)BF(\psi(3770) \to D\bar{D})=(83.9 \pm 1.6 \pm 5.7)%, which result in the total non-DDˉD\bar D branching fraction of ψ(3770)\psi(3770) decay to be BF(ψ(3770)nonDDˉ)=(16.1±1.6±5.7)BF(\psi(3770) \to {\rm non}-D\bar D)=(16.1 \pm 1.6 \pm 5.7)%.Comment: 11 pages, 5 figure

    Precison Measurements of the Mass, the Widths of ψ(3770)\psi(3770) Resonance and the Cross Section σ[e+eψ(3770)]\sigma[e^+e^-\to \psi(3770)] at Ecm=3.7724E_{\rm cm}=3.7724 GeV

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    By analyzing the RR values measured at 68 energy points in the energy region between 3.650 and 3.872 GeV reported in our previous paper, we have precisely measured the mass, the total width, the leptonic width and the leptonic decay branching fraction of the ψ(3770)\psi(3770) to be Mψ(3770)=3772.4±0.4±0.3{M}_{\psi(3770)}=3772.4 \pm 0.4 \pm 0.3 MeV, Γψ(3770)tot=28.6±1.2±0.2\Gamma_{\psi(3770)}^{\rm tot} = 28.6 \pm 1.2 \pm 0.2 MeV, Γψ(3770)ee=279±11±13\Gamma_{\psi(3770)}^{ee} = 279 \pm 11 \pm 13 eV and B[ψ(3770)e+e]=(0.98±0.04±0.04)×105B[\psi(3770)\to e^+e^-]=(0.98\pm 0.04\pm 0.04)\times 10^{-5}, respectively, which result in the observed cross section σobs[e+eψ(3770)]=7.25±0.27±0.34\sigma^{\rm obs}[e^+e^-\to \psi(3770)]=7.25\pm 0.27 \pm 0.34 nb at s=3772.4\sqrt{s}=3772.4 MeV. We have also measured Ruds=2.121±0.023±0.084R_{\rm uds}=2.121\pm 0.023 \pm 0.084 for the continuum light hadron production in the region from 3.650 to 3.872 GeV.Comment: 5 pages, 2 figure

    QCD Corrections and Non-standard Three Vector Boson Couplings in W+WW^+W^- Production at Hadron Colliders

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    The process p\,p\hskip-7pt\hbox{^{^{(\!-\!)}}} \rightarrow W^{+} W^{-} + X \rightarrow \ell^+_1 \nu_1 \ell^-_2 \bar \nu_2 + X is calculated to O(αs){\cal O}(\alpha_s) for general CC and PP conserving WWVWWV couplings (V=γ,ZV=\gamma,\, Z). The prospects for probing the WWVWWV couplings in this reaction are explored. The impact of O(αs){\cal O}(\alpha_s) QCD corrections and various background processes on the observability of non-standard WWVWWV couplings in W+WW^+ W^- production at the Tevatron and the Large Hadron Collider (LHC) is discussed in detail. Sensitivity limits for anomalous WWVWWV couplings are derived at next-to-leading order for the Tevatron and LHC center of mass energies, and are compared to the bounds which can be achieved in other processes. Unless a jet veto or a cut on the total transverse momentum of the hadrons in the event is imposed, the O(αs){\cal O}(\alpha_s) QCD corrections and the background from top quark production decrease the sensitivity of p\,p\hskip-7pt\hbox{^{^{(\!-\!)}}} \rightarrow W^{+} W^{-} + X \rightarrow \ell^+_1 \nu_1 \ell^-_2 \bar \nu_2 + X to anomalous WWVWWV couplings by a factor two to five.Comment: REVTEX 3, 62 pages, 21 Figures (not included available upon request), the postscript file of the complete paper is available at ftp://ucdhep.ucdavis.edu/han/ww/ww_paper.p

    De restauratie van 'Marienberg', vijf woningen in het restant van een klooster

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    Beschrijving van de restauratie met historische bijzonderheden
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