193 research outputs found

    Symposium: Pandemics and the Constitution: Federalism and Contagion: Reevaluating the Role of the CDC

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    The United States Government’s response to the coronavirus outbreak raises difficult questions of federalism. This essay argues for greater federal leadership and involvement to mount the most effective response to a pandemic. As history shows, a response led by local governments is vulnerable to collective action problems and political impediments. An improved response structure in a contagious disease event would include more federal leadership and policy dictated by the Centers for Disease Control (CDC), to be then effectuated by state and local governments. This power can be exercised either formally, through federal grants, or informally through the influence of public locally-focused CDC recommendations. Second, this essay argues for greater federal influence over public health measures such as quarantine and isolation for a more uniform national response. As the law now exists, federal authority over everything but international border quarantines is somewhat ambiguous. State and local governments have exercised quarantine authority inconsistently, and may not possess the institutional knowledge to weigh the costs and benefits of confinement actions. Inevitably during a severe pandemic, localities may also push the limits of their authority to quarantine, potentially in opposition to federal government policy, hindering a nationwide pandemic response. Implicit in this recommendation is a call for greater statutory authorization for the CDC. Finally, the potential constitutional questions that arise from the suggested policy alterations are considered. Government officials are always in a challenging position when responding to a pandemic. This challenge is magnified when federal authority over the matter is unclear. The United States system of public health federalism must be rebalanced in some areas, to gain an effective uniform response to an outbreak of disease

    Quadrupole Anisotropy in Dihadron Azimuthal Correlations in Central dd++Au Collisions at sNN\sqrt{s_{_{NN}}}=200 GeV

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    The PHENIX collaboration at the Relativistic Heavy Ion Collider (RHIC) reports measurements of azimuthal dihadron correlations near midrapidity in dd++Au collisions at sNN\sqrt{s_{_{NN}}}=200 GeV. These measurements complement recent analyses by experiments at the Large Hadron Collider (LHC) involving central pp++Pb collisions at sNN\sqrt{s_{_{NN}}}=5.02 TeV, which have indicated strong anisotropic long-range correlations in angular distributions of hadron pairs. The origin of these anisotropies is currently unknown. Various competing explanations include parton saturation and hydrodynamic flow. We observe qualitatively similar, but larger, anisotropies in dd++Au collisions compared to those seen in pp++Pb collisions at the LHC. The larger extracted v2v_2 values in dd++Au collisions at RHIC are consistent with expectations from hydrodynamic calculations owing to the larger expected initial-state eccentricity compared with that from pp++Pb collisions. When both are divided by an estimate of the initial-state eccentricity the scaled anisotropies follow a common trend with multiplicity that may extend to heavy ion data at RHIC and the LHC, where the anisotropies are widely thought to arise from hydrodynamic flow.Comment: 375 authors, 7 pages, 5 figures. Published in Phys. Rev. Lett. v2 has minor changes to text and figures in response to PRL referee suggestions. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    ϕ\phi meson production in dd++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV

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    The PHENIX experiment has measured ϕ\phi meson production in dd++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV using the dimuon and dielectron decay channels. The ϕ\phi meson is measured in the forward (backward) dd-going (Au-going) direction, 1.2<y<2.21.2<y<2.2 (2.2<y<1.2-2.2<y<-1.2) in the transverse-momentum (pTp_T) range from 1--7 GeV/cc, and at midrapidity y<0.35|y|<0.35 in the pTp_T range below 7 GeV/cc. The ϕ\phi meson invariant yields and nuclear-modification factors as a function of pTp_T, rapidity, and centrality are reported. An enhancement of ϕ\phi meson production is observed in the Au-going direction, while suppression is seen in the dd-going direction, and no modification is observed at midrapidity relative to the yield in pp++pp collisions scaled by the number of binary collisions. Similar behavior was previously observed for inclusive charged hadrons and open heavy flavor indicating similar cold-nuclear-matter effects.Comment: 484 authors, 16 pages, 12 figures, 6 tables. v1 is the version accepted for publication in Phys. Rev. C. Data tables for the points plotted in the figures are given in the paper itsel

    Centrality categorization for R_{p(d)+A} in high-energy collisions

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    High-energy proton- and deuteron-nucleus collisions provide an excellent tool for studying a wide array of physics effects, including modifications of parton distribution functions in nuclei, gluon saturation, and color neutralization and hadronization in a nuclear environment, among others. All of these effects are expected to have a significant dependence on the size of the nuclear target and the impact parameter of the collision, also known as the collision centrality. In this article, we detail a method for determining centrality classes in p(d)+A collisions via cuts on the multiplicity at backward rapidity (i.e., the nucleus-going direction) and for determining systematic uncertainties in this procedure. For d+Au collisions at sqrt(s_NN) = 200 GeV we find that the connection to geometry is confirmed by measuring the fraction of events in which a neutron from the deuteron does not interact with the nucleus. As an application, we consider the nuclear modification factors R_{p(d)+A}, for which there is a potential bias in the measured centrality dependent yields due to auto-correlations between the process of interest and the backward rapidity multiplicity. We determine the bias correction factor within this framework. This method is further tested using the HIJING Monte Carlo generator. We find that for d+Au collisions at sqrt(s_NN)=200 GeV, these bias corrections are small and vary by less than 5% (10%) up to p_T = 10 (20) GeV. In contrast, for p+Pb collisions at sqrt(s_NN) = 5.02 TeV we find these bias factors are an order of magnitude larger and strongly p_T dependent, likely due to the larger effect of multi-parton interactions.Comment: 375 authors, 18 pages, 16 figures, 4 tables. Submitted to Phys. Rev. C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    L\'evy-stable two-pion Bose-Einstein correlations in sNN=200\sqrt{s_{_{NN}}}=200 GeV Au++Au collisions

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    We present a detailed measurement of charged two-pion correlation functions in 0%-30% centrality sNN=200\sqrt{s_{_{NN}}}=200 GeV Au++Au collisions by the PHENIX experiment at the Relativistic Heavy Ion Collider. The data are well described by Bose-Einstein correlation functions stemming from L\'evy-stable source distributions. Using a fine transverse momentum binning, we extract the correlation strength parameter λ\lambda, the L\'evy index of stability α\alpha and the L\'evy length scale parameter RR as a function of average transverse mass of the pair mTm_T. We find that the positively and the negatively charged pion pairs yield consistent results, and their correlation functions are represented, within uncertainties, by the same L\'evy-stable source functions. The λ(mT)\lambda(m_T) measurements indicate a decrease of the strength of the correlations at low mTm_T. The L\'evy length scale parameter R(mT)R(m_T) decreases with increasing mTm_T, following a hydrodynamically predicted type of scaling behavior. The values of the L\'evy index of stability α\alpha are found to be significantly lower than the Gaussian case of α=2\alpha=2, but also significantly larger than the conjectured value that may characterize the critical point of a second-order quark-hadron phase transition.Comment: 448 authors, 25 pages, 11 figures, 4 tables, 2010 data. v2 is version accepted for publication in Phys. Rev. C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Cross Section and Transverse Single-Spin Asymmetry of η\eta Mesons in p+pp^{\uparrow}+p Collisions at s=200\sqrt{s}=200 GeV at Forward Rapidity

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    We present a measurement of the cross section and transverse single-spin asymmetry (ANA_N) for η\eta mesons at large pseudorapidity from s=200\sqrt{s}=200~GeV p+pp^{\uparrow}+p collisions. The measured cross section for 0.5<pT<5.00.5<p_T<5.0~GeV/cc and 3.0<η<3.83.0<|\eta|<3.8 is well described by a next-to-leading-order perturbative-quantum-chromodynamics calculation. The asymmetries ANA_N have been measured as a function of Feynman-xx (xFx_F) from 0.2<xF<0.70.2<|x_{F}|<0.7, as well as transverse momentum (pTp_T) from 1.0<pT<4.51.0<p_T<4.5~GeV/cc. The asymmetry averaged over positive xFx_F is AN=0.061±0.014\langle{A_{N}}\rangle=0.061{\pm}0.014. The results are consistent with prior transverse single-spin measurements of forward η\eta and π0\pi^{0} mesons at various energies in overlapping xFx_F ranges. Comparison of different particle species can help to determine the origin of the large observed asymmetries in p+pp^{\uparrow}+p collisions.Comment: 484 authors, 13 pages, 11 figures, 4 tables, 2008 data. v2 is version accepted by Phys. Rev. D. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be)publicly available at http://www.phenix.bnl.gov/papers.htm

    Cross section for bbˉb\bar{b} production via dielectrons in d++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV

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    We report a measurement of e+ee^+e^- pairs from semileptonic heavy-flavor decays in dd++Au collisions at sNN=200\sqrt{s_{_{NN}}}=200 GeV. Exploring the mass and transverse-momentum dependence of the yield, the bottom decay contribution can be isolated from charm, and quantified by comparison to {\sc pythia} and {\sc mc@nlo} simulations. The resulting bbˉb\bar{b}-production cross section is σbbˉdAu=1.37±0.28(stat)±0.46(syst)\sigma^{d{\rm Au}}_{b\bar{b}}=1.37{\pm}0.28({\rm stat}){\pm}0.46({\rm syst})~mb, which is equivalent to a nucleon-nucleon cross section of σbbNN=3.4±0.8(stat)±1.1(syst) μ\sigma^{NN}_{bb}=3.4\pm0.8({\rm stat}){\pm}1.1({\rm syst})\ \mub.Comment: 375 authors, 16 pages, 8 figures, 7 tables, 2008 data. Submitted to Phys. Rev. C Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
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