Direct virtual photon production in Au+Au collisions atsNN=200\ua0GeV

We report the direct virtual photon invariant yields in the transverse momentum ranges 16 GeV/c the production follows TAA scaling. Model calculations with contributions from thermal radiation and initial hard parton scattering are consistent within uncertainties with the direct virtual photon invariant yield

Collision energy dependence of moments of net-kaon multiplicity distributions at RHIC

Fluctuations of conserved quantities such as baryon number, charge, and strangeness are sensitive to the correlation length of the hot and dense matter created in relativistic heavy-ion collisions and can be used to search for the QCD critical point. We report the first measurements of the moments of net-kaon multiplicity distributions in Au+Au collisions at sNN=7.7 , 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV. The collision centrality and energy dependence of the mean ( M ), variance ( \u3c32 ), skewness ( S ), and kurtosis ( \u3ba ) for net-kaon multiplicity distributions as well as the ratio \u3c32/M and the products S\u3c3 and \u3ba\u3c32 are presented. Comparisons are made with Poisson and negative binomial baseline calculations as well as with UrQMD, a transport model (UrQMD) that does not include effects from the QCD critical point. Within current uncertainties, the net-kaon cumulant ratios appear to be monotonic as a function of collision energy

Energy dependence of J/\u3c8 production in Au + Au collisions at s NN =39,62.4 and 200GeV

The inclusive J/\u3c8 transverse momentum spectra and nuclear modification factors are reported at mid-rapidity ( |y|<1.0 ) in Au + Au collisions at sNN = 39, 62.4 and 200 GeV taken by the STAR experiment. A suppression of J/\u3c8 production, with respect to the production in p+p scaled by the number of binary nucleon\u2013nucleon collisions, is observed in central Au + Au collisions at these three energies. No significant energy dependence of nuclear modification factors is found within uncertainties. The measured nuclear modification factors can be described by model calculations that take into account both suppression of direct J/\u3c8 production due to the color screening effect and J/\u3c8 regeneration from recombination of uncorrelated charm\u2013anticharm quark pairs

Beam-Energy Dependence of Directed Flow of \u39b, \u39b , K\ub1, Ks0, and \u3c6 in Au+Au Collisions

Rapidity-odd directed-flow measurements at midrapidity are presented for \u39b, \u39b\uaf, K\ub1, Ks0, and \u3d5 at sNN=7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV in Au+Au collisions recorded by the Solenoidal Tracker detector at the Relativistic Heavy Ion Collider. These measurements greatly expand the scope of data available to constrain models with differing prescriptions for the equation of state of quantum chromodynamics. Results show good sensitivity for testing a picture where flow is assumed to be imposed before hadron formation and the observed particles are assumed to form via coalescence of constituent quarks. The pattern of departure from a coalescence-inspired sum rule can be a valuable new tool for probing the collision dynamics

Elliptic flow of identified hadrons in Pb-Pb collisions at 1asNN = 2.76 TeV

The elliptic flow coefficient (v2) of identified particles in Pb-Pb collisions at 1asNN = 2.76 TeV was measured with the ALICE detector at the Large Hadron Collider (LHC). The results were obtained with the Scalar Product method, a two-particle corre- lation technique, using a pseudo-rapidity gap of | 06\u3b7| > 0.9 between the identified hadron under study and the reference particles. The v2 is reported for \u3c0\ub1, K\ub1, K0S, p+p, \u3c6, \u39b+\u39b, \u39e 12+\u39e+ and \u3a9 12+\u3a9+ in several collision centralities. In the low transverse momentum (pT) region, pT 3 GeV/c

Centrality dependence of high-pT D meson suppression in Pb-Pb collisions at 1asNN = 2.76 TeV

The nuclear modification factor, RAA, of the prompt charmed mesons D0, D+ and D 17+, and their antiparticles, was measured with the ALICE detector in Pb-Pb collisions at a centre-of-mass energy 1asNN = 2.76 TeV in two transverse momentum intervals, 5 < pT < 8GeV/c and 8 < pT < 16GeV/c, and in six collision centrality classes. The RAA shows a maximum suppression of a factor of 5\u20136 in the 10% most central collisions. The suppression and its centrality dependence are compatible within uncertainties with those of charged pions. A comparison with the RAA of non-prompt J/\u3c8 from B meson decays, measured by the CMS Collaboration, hints at a larger suppression of D mesons in the most central collisions

Centrality dependence of inclusive J/\u3c8 production in p-Pb collisions at 1asNN = 5.02 TeV

We present a measurement of inclusive J/\u3c8 production in p-Pb collisions at 1asNN = 5.02TeV as a function of the centrality of the collision, as estimated from the energy deposited in the Zero Degree Calorimeters. The measurement is performed with the ALICE detector down to zero transverse momentum, pT, in the backward ( 124.46 < ycms < 122.96) and forward (2.03 < ycms < 3.53) rapidity intervals in the dimuon decay channel and in the mid-rapidity region ( 121.37 < ycms < 0.43) in the dielectron decay channel. The backward and forward rapidity intervals correspond to the Pb-going and p-going direction, respectively. The pT-differential J/\u3c8 production cross section at backward and forward rapidity is measured for several centrality classes, together with the corresponding average pT and pT2 values. The nuclear modification factor is presented as a function of centrality for the three rapidity intervals, and as a function of pT for several centrality classes at backward and forward rapidity. At mid- and forward rapidity, the J/\u3c8 yield is suppressed up to 40% compared to that in pp interactions scaled by the number of binary collisions. The degree of suppression increases towards central p-Pb collisions at forward rapidity, and with decreasing pT of the J/\u3c8. At backward rapidity, the nuclear modification factor is compatible with unity within the total uncertainties, with an increasing trend from peripheral to central p-Pb collisions

White paper on Next Generation Metrics

We - the writers - of this paper summarise a methodological debate amongst experts from our\ua0Members on \ub4traditional\ub4 and \ub4next generation metrics\ub4 for science, education and innovation in\ua0the light of the developments and expectations towards greater \ub4openness\ub4 to realise long-term\ua0ecological, economic and social sustainability and benefit to citizens and to the world. A broad\ua0range of indicators from various sources were discussed in terms of feasibility in different\ua0contexts, as well as their suitability to serve diverse purposes. Rather than presenting a formal\ua0position on behalf of CESAER, we present our synthesis of this debate. In chapter one, we provide\ua0the definitions, describe the methodology used and set the scope of this paper, thus setting the\ua0scene for the following chapters.In chapter two, we report on our findings on metrics dealing with (open) science. Ever since E.\ua0Garfield’s Journal Impact Factor (JIF) came into use in the mid-70s, and certainly with the h-index\ua0proposed by the physicist J. E. Hirsch in 2005, the rise of quantitative metrics in the assessment\ua0of research has seemed to be unstoppable - up to the use of \ub4views\ub4, \ub4likes\ub4 and \ub4tweets\ub4. While\ua0in times of accountability and competing for visibility and funds, it is only reasonable to focus on\ua0the measurability and comparability of metrics as efficient means to display performance, the\ua0limitations of doing so are obvious. As a result, in the past years, a countermovement criticising\ua0this practice and questioning the validity of the metrics and reliability of the data used has become\ua0stronger. Moreover, there are strong (political) expectations to make science more open.\ua0Metrics for (open) education and training are the topic of chapter three. In many (global) rankings\ua0of higher education institutions, the indicators used reflect the model of traditional, established,\ua0wealthy and largely English-speaking research universities (Hazelkorn, 2015). They are,\ua0therefore, ill-suited to truly give an idea about the quality or the performance of higher education\ua0more broadly, and they are limited in helping universities to set priorities. They do, however, reveal\ua0that there is still a lack of meaningful internationally comparable information on these matters.\ua0By covering (open) innovation in chapter four, we complete the discussion of the mission of our\ua0Members. Open innovation promotes approaches that boost disruptive innovation rather than\ua0incremental, stimulate inventions produced by outsiders and founders in start-ups, and is based\ua0on a view on the world of widely distributed knowledge.We synthesised our findings on the confrontation between \ub4traditional\ub4 and \ub4next generation\ua0metrics\ub4 and present ten each for science, education and innovation for use mainly within our\ua0Members and to monitor the desired progress over time (see annexe I).\ua0While this might be interpreted as sufficient responsiveness to external expectations on our\ua0behalf, we instead advanced further and in chapter five suggest that universities strive towards\ua0\ub4progressive metrics\ub4 and highlight the need to acknowledge knowledge as a common good,\ua0promote a culture of quality, risk-taking and trust and measure the contribution to sustainability.\ua0That is why we conclude this paper with ideas for progressive indicators in annexe II, outlining an\ua0agenda for future work to stay at the forefront of science, education and innovation; to benchmark\ua0against like-minded institutions; and to pursue institutional development paths; and - ultimately -\ua0to optimise our contributions to society and the world

Measurement of D0 Azimuthal Anisotropy at Midrapidity in Au+Au Collisions at sNN =200 GeV

We report the first measurement of the elliptic anisotropy (v2) of the charm meson D0 at midrapidity (|y|<1) in Au+Au collisions at sNN=200\u2009\u2009GeV. The measurement was conducted by the STAR experiment at RHIC utilizing a new high-resolution silicon tracker. The measured D0 v2 in 0%\u201380% centrality Au+Au collisions can be described by a viscous hydrodynamic calculation for a transverse momentum (pT) of less than 4\u2009\u2009GeV/c. The D0 v2 as a function of transverse kinetic energy (mT-m0, where mT=pT2+m02) is consistent with that of light mesons in 10%\u201340% centrality Au+Au collisions. These results suggest that charm quarks have achieved local thermal equilibrium with the medium created in such collisions. Several theoretical models, with the temperature-dependent, dimensionless charm spatial diffusion coefficient (2\u3c0TDs) in the range of 3c2\u201312, are able to simultaneously reproduce our D0 v2 result and our previously published results for the D0 nuclear modification factor

Dijet imbalance measurements in Au+Au and pp collisions at sNN =200 GeV at STAR

We report the first dijet transverse momentum asymmetry measurements from Au+Au and pp collisions at RHIC. The two highest-energy back-to-back jets reconstructed from fragments with transverse momenta above 2\u2009\u2009GeV/c display a significantly higher momentum imbalance in heavy-ion collisions than in the pp reference. When reexamined with correlated soft particles included, we observe that these dijets then exhibit a unique new feature\u2014momentum balance is restored to that observed in pp for a jet resolution parameter of R=0.4, while rebalancing is not attained with a smaller value of R=0.2