Long-range Angular Correlations On The Near And Away Side In P-pb Collisions At √snn=5.02 Tev

7191/Mar294

Measurement of jet suppression in central Pb-Pb collisions at root s(NN)=2.76 TeV

The transverse momentum(p(T)) spectrum and nuclear modification factor (R-AA) of reconstructed jets in 0-10% and 10-30% central Pb-Pb collisions at root s(NN) = 2.76 TeV were measured. Jets were reconstructed using the anti-k(T) jet algorithm with a resolution parameter of R = 0.2 from charged and neutral particles, utilizing the ALICE tracking detectors and Electromagnetic Calorimeter (EMCal). The jet p(T) spectra are reported in the pseudorapidity interval of \eta(jet)\ 5 GeV/c to suppress jets constructed from the combinatorial background in Pb-Pb collisions. The leading charged particle requirement applied to jet spectra both in pp and Pb-Pb collisions had a negligible effect on the R-AA. The nuclear modification factor R-AA was found to be 0.28 +/- 0.04 in 0-10% and 0.35 +/- 0.04 in 10-30% collisions, independent of p(T), jet within the uncertainties of the measurement. The observed suppression is in fair agreement with expectations from two model calculations with different approaches to jet quenching. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.Peer reviewe

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

First measurement of Ωc0 production in pp collisions at s=13 TeV

The inclusive production of the charm–strange baryon 0 c is measured for the first time via its hadronic √ decay into −π+ at midrapidity (|y| &lt;0.5) in proton–proton (pp) collisions at the centre-of-mass energy s =13 TeV with the ALICE detector at the LHC. The transverse momentum (pT) differential cross section multiplied by the branching ratio is presented in the interval 2 &lt; pT &lt; 12 GeV/c. The pT dependence of the 0 c-baryon production relative to the prompt D0-meson and to the prompt 0 c-baryon production is compared to various models that take different hadronisation mechanisms into consideration. In the measured pT interval, the ratio of the pT-integrated cross sections of 0 c and prompt + c baryons multiplied by the −π+ branching ratio is found to be larger by a factor of about 20 with a significance of about 4σ when compared to e+e− collisions

Elliptic flow of charged particles at midrapidity relative to the spectator plane in Pb–Pb and Xe–Xe collisions

Measurements of the elliptic flow coefficient relative to the collision plane defined by the spectator neutrons v2{ SP} in collisions of Pb ions at center-of-mass energy per nucleon–nucleon pair √ 2.76 TeV and Xe ions at √ sNN = sNN =5.44 TeV are reported. The results are presented for charged particles produced at midrapidity as a function of centrality and transverse momentum for the 5–70% and 0.2–6 GeV/c ranges, respectively. The ratio between v2{ SP} and the elliptic flow coefficient relative to the participant plane v2{4}, estimated using four-particle correlations, deviates by up to 20% from unity depending on centrality. This observation differs strongly from the magnitude of the corresponding eccentricity ratios predicted by the TRENTo and the elliptic power models of initial state fluctuations that are tuned to describe the participant plane anisotropies. The differences can be interpreted as a decorrelation of the neutron spectator plane and the reaction plane because of fragmentation of the remnants from the colliding nuclei, which points to an incompleteness of current models describing the initial state fluctuations. A significant transverse momentum dependence of the ratio v2{ SP}/v2{4} is observed in all but the most central collisions, which may help to understand whether momentum anisotropies at low and intermediate transverse momentum have a common origin in initial state f luctuations. The ratios of v2{ SP} and v2{4} to the corresponding initial state eccentricities for Xe–Xe and Pb–Pb collisions at similar initial entropy density show a difference of (7.0 ±0.9)%with an additional variation of +1.8% when including RHIC data in the TRENTo parameter extraction. These observations provide new experimental constraints for viscous effects in the hydrodynamic modeling of the expanding quark–gluon plasma produced in heavy-ion collisions at the LHC

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

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities 1,2 . This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity 3�6 . Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55 of the global rise in mean BMI from 1985 to 2017�and more than 80 in some low- and middle-income regions�was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing�and in some countries reversal�of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories. © 2019, The Author(s)

The microstructure of ferrofluids and their rheological properties

One of the most important features of ferrofluids is the possibility to change their physical properties, especially their viscosity, by means of moderate magnetic fields. This capability makes ferrofluids very useful in the fields of engineering, medicine and fundamental research. Rheological experimental results, as well as theoretical studies, correlate the change of the viscosity of a sheared ferrofluid under the influence of a magnetic field, the so called magnetoviscous effect, to the internal structure formation under certain external conditions. To obtain information about the microstructure of ferrofluids, experiments using the small angle neutron scattering SANS technique have been carried out. Three magnetite based ferrofluids with different particle particle interactions, and thus various magnitudes of the magnetoviscous effect, were investigated. Using a specially designed rheometer, SANS experiments were performed for different shear rates and magnetic field strengths in order to observe the modification of the microstructure in ferrofluids and to associate the SANS information with their macroscopical behaviour. The scattering patterns obtained show a good agreement with the qualitative model that explains the magnetoviscous effec

Microstructure and rheology of ferrofluids

Experimental studies made for different ferrofluid samples under shear flow have shown that increasing the magnetic field strength yields an increase of the fluids viscosity, the so called magnetoviscous effect, while increasing shear rate leads to a decrease of the magnitude of the viscosity shear thinning . The change of the viscosity with magnetic field strength is theoretically explained as an effect of chain like structure formation in ferrofluids whereas its magnitude depends on the particle particle interaction. Both effects, the shear thinning and the magnetoviscous effect, can therefore be related to the microstructure and microstructure dynamics of ferrofluids. Using a specially designed rheometer, ferrofluids having different magnitude of the magnetoviscous effect were investigated by small angle neutron scattering. Correlated to the structure formation in the fluid, the scattered intensity shows a variation with the magnetic field and shear rate only in the case of the fluids with a high magnetoviscous effect. The presented results show that there is a strong connection between the rheological behaviour of ferrofluids and their microstructur