Erratum: Evolution of π

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

Azimuthal-angle dependence of charged-pion-interferometry measurements with respect to second- and third-order event planes in Au+Au collisions at √[S(NN)]=200 GeV.

Charged-pion-interferometry measurements were made with respect to the second- and third-order event plane for Au+Au collisions at sqrt[s_{NN}]=200 GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the second- and third-order event planes. The results for the second-order dependence indicate that the initial eccentricity is reduced during the medium evolution, which is consistent with previous results. In contrast, the results for the third-order dependence indicate that the initial triangular shape is significantly reduced and potentially reversed by the end of the medium evolution, and that the third-order oscillations are largely dominated by the dynamical effects from triangular flow.

Quadrupole anisotropy in dihadron azimuthal correlations in central d+Au collisions at √(s(NN))=200 GeV.

The PHENIX collaboration at the Relativistic Heavy Ion Collider (RHIC) reports measurements of azimuthal dihadron correlations near midrapidity in d+Au collisions at √(s(NN))=200 GeV. These measurements complement recent analyses by experiments at the Large Hadron Collider (LHC) involving central p+Pb collisions at √(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 d+Au collisions at RHIC compared to those seen in p+Pb collisions at the LHC. The larger extracted v2 values in d+Au are consistent with expectations from hydrodynamic calculations owing to the larger expected initial-state eccentricity compared with that from p+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.

Nuclear modification of ψ', χc, and J/ψ production in d+Au collisions at sqrt[s(NN)]=200 GeV.

We present results for three charmonia states (ψ', χc, and J/ψ) in d+Au collisions at |y|<0.35 and sqrt[s(NN)]=200 GeV. We find that the modification of the ψ' yield relative to that of the J/ψ scales approximately with charged particle multiplicity at midrapidity across p+A, d+Au, and A+A results from the Super Proton Synchrotron and the Relativistic Heavy Ion Collider. In large-impact-parameter collisions we observe a similar suppression for the ψ' and J/ψ, while in small-impact-parameter collisions the more weakly bound ψ' is more strongly suppressed. Owing to the short time spent traversing the Au nucleus, the larger ψ' suppression in central events is not explained by an increase of the nuclear absorption owing to meson formation time effects.

Observation of direct-photon collective flow in Au + Au collisions at √s(NN)] = 200 GeV.

The second Fourier component v(2) of the azimuthal anisotropy with respect to the reaction plane is measured for direct photons at midrapidity and transverse momentum (p(T)) of 1-12 GeV/c in Au + Au collisions at √s(NN)] = 200 GeV. Previous measurements of this quantity for hadrons with p(T) < 6 GeV/c indicate that the medium behaves like a nearly perfect fluid, while for p(T) > 6 GeV/c a reduced anisotropy is interpreted in terms of a path-length dependence for parton energy loss. In this measurement with the PHENIX detector at the Relativistic Heavy Ion Collider we find that for p(T) > 4 GeV/c the anisotropy for direct photons is consistent with zero, which is as expected if the dominant source of direct photons is initial hard scattering. However, in the p(T) < 4 GeV/c region dominated by thermal photons, we find a substantial direct-photon v(2) comparable to that of hadrons, whereas model calculations for thermal photons in this kinematic region underpredict the observed v(2).

Evolution of π(0) suppression in Au+Au collisions from √(s(NN))=39 to 200 GeV.

Neutral-pion π(0) spectra were measured at midrapidity (|y|<0.35) in Au+Au collisions at √(s(NN))=39 and 62.4 GeV and compared with earlier measurements at 200 GeV in a transverse-momentum range of 1

Cold-nuclear-matter effects on heavy-quark production in d+Au collisions at sqrt[S(NN)]=200 GeV.

The PHENIX experiment has measured electrons and positrons at midrapidity from the decays of hadrons containing charm and bottom quarks produced in d+Au and p+p collisions at sqrt[S(NN)]=200 GeV in the transverse-momentum range 0.85 ≤ p(T)(e) ≤ 8.5 GeV/c. In central d+Au collisions, the nuclear modification factor R(dA) at 1.5

Heavy cluster knockout reaction (16)O((12)C,2(12)C)(4)He and the nature of the (12)C-(12)C interaction potential.

The heavy cluster knockout reaction (16)O((12)C,2(12)C)(4)He performed for the first time, reveals the true nature of the (12)C-(12)C interaction. The observed cross section is enhanced by almost 2 orders of magnitude over the conventional zero range distorted wave impulse approximation (DWIA) predictions. An attractive (12)C-(12)C optical potential, as obtained in the folding model, does not explain the enhanced cross section in the finite range (FR) DWIA framework. The inclusion of a hard core of fairly long range ∼3.65 fm explains the data. The present investigation of (16)O((12)C,2(12)C)(4)He along with the (12)C-(12)C elastic scattering also proves beyond doubt that the folding model's deep attractive heavy ion potentials are unsuitable to describe the highly overlapping heavy ions. The application of FR-DWIA opens up new avenues to use the heavy core knockout for the detailed investigation of heavy as well as Borromean halo nuclei.

Measurements of higher order flow harmonics in Au+Au collisions at √s(NN)=200 GeV.

Flow coefficients ν(n) for n=2, 3, 4, characterizing the anisotropic collective flow in Au+Au collisions at √s(NN)=200 GeV, are measured relative to event planes Ψ(n), determined at large rapidity. We report ν(n) as a function of transverse momentum and collision centrality, and study the correlations among the event planes of different order n. The ν(n) are well described by hydrodynamic models which employ a Glauber Monte Carlo initial state geometry with fluctuations, providing additional constraining power on the interplay between initial conditions and the effects of viscosity as the system evolves. This new constraint can serve to improve the precision of the extracted shear viscosity to entropy density ratio η/s.

Suppression of back-to-back hadron pairs at forward rapidity in d+Au collisions at √s(NN)=200 GeV.

Back-to-back hadron pair yields in d+Au and p+p collisions at √s(NN)=200 GeV were measured with the PHENIX detector at the Relativistic Heavy Ion Collider. Rapidity separated hadron pairs were detected with the trigger hadron at pseudorapidity |η|<0.35 and the associated hadron at forward rapidity (deuteron direction, 3.0<η<3.8). Pairs were also detected with both hadrons measured at forward rapidity; in this case, the yield of back-to-back hadron pairs in d+Au collisions with small impact parameters is observed to be suppressed by a factor of 10 relative to p+p collisions. The kinematics of these pairs is expected to probe partons in the Au nucleus with a low fraction x of the nucleon momenta, where the gluon densities rise sharply. The observed suppression as a function of nuclear thickness, p(T), and η points to cold nuclear matter effects arising at high parton densities.

Low energy proton beam induces efficient cell killing in A549 lung adenocarcinoma cells.

The aim of the current study was to determine the signaling differences between gamma- and proton beam-irradiations. A549 lung adenocarcinoma cells were irradiated with 2 Gy proton beam or gamma-radiation. Proton beam was found to be more cytotoxic than gamma-radiation. Proton beam-irradiated cells showed phosphorylation of H2AX, ATM, Chk2, and p53. The mechanism of excessive cell killing in proton beam-irradiated cells was found to be upregulation of Bax and downregulation of Bcl-2. The noteworthy finding of this study is the biphasic activation of the sensor proteins, ATM, and DNA-PK and no activation of ATR by proton irradiation.

Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sq.rt(s(NN))=200 GeV.

Differential measurements of the elliptic (v(2)) and hexadecapole (v(4)) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum (p(T)) and collision centrality or number of participant nucleons (N(part)) for Au+Au collisions at sq.rt(s(NN))=200 GeV. The v(2,4) measurements at pseudorapidity |η|≤0.35, obtained with four separate reaction-plane detectors positioned in the range 1.0<|η|<3.9, show good agreement, indicating the absence of significant Δη-dependent nonflow correlations. Sizable values for v(4)(p(T)) are observed with a ratio v(4)(p(T),N(part))/v(2)(2)(p(T),N(part))≈0.8 for 50≲N(part)≲200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For N(part)≳200 this ratio increases up to 1.7 in the most central collisions.

Azimuthal anisotropy of π° production in Au+Au collisions at sqrt((s)NN)=200 GeV: path-length dependence of jet quenching and the role of initial geometry.

We have measured the azimuthal anisotropy of π° production for 1

Studies of blood lead levels in children by proton-induced X-ray emission (PIXE).

Blood lead levels of children admitted to Sion Hospital, Bombay (India), from the adjoining Dharavi slum areas have been determined by proton-induced X-ray emission (PIXE). Blood samples were collected from 36 children with suspected lead poisoning and from 20 control children. The analysis showed that the lead concentration of the patients varied from 0.1 to 6.0 micrograms ml-1. In addition to lead, K, Ca, Fe, Cu, Zn, Se, Br and Rb were also detected simultaneously, of which the concentrations of Fe, Cu, Zn, Se, Rb and Pb were determined. The high blood lead levels of the children from this area may be ascribed to environmental pollution due to heavy vehicular traffic and industrial sources.

Trace element profiles in oesophageal neoplasms determined by proton-induced X-ray emission.

Trace element concentrations were determined in surgically resected, cancerous human oesophageal tissue by proton-induced X-ray emission (PIXE) analysis. Each sample was divided into six zones, E3 and E4 formed the central tumour region, E1 and E2 were proximal to the oesophagus and E5 and E6 distal to the oesophagus. Malignancy was confirmed histopathologically in all cases. Samples were dissolved in NaOH solution and pipetted onto a thin mylar film for analysis by a proton beam from a Van de Graaff accelerator. Titanium, Fe, Cu, Zn, As, Rb, Br and Pb were detected in varying concentrations. Of these, Ti, Fe, Cu, Zn and As showed specific behaviour in the six zones.

Study of trace element correlations with drought tolerance in different sorghum genotypes using energy-dispersive X-ray fluorescence technique.

Drought-tolerant and drought-susceptible genotypes of sorghum (Sorghum bicolor L. Monech) were analyzed by the energy-dispersive X-ray fluorescence (EDXRF) technique to study the correlation of trace elements with drought-tolerance capacities. Samples prepared from mature seeds, young seedlings, and old plants were analyzed using a 109Cd radioisotope source and a Si(Li) semiconductor detector of resolution 170 eV for 5.9-keV MnKalpha X-rays. Elements such as K, Fe, Cu, Zn, Rb and Sr and Y were found to be present in varying concentrations in different samples. The trace element profile studied in the seeds of 11 genotypes and in seedlings (young and old) of 4 sorghum genotypes showed considerable variation. The genotype Arfa Gadamak (AG) showed a distinct presence of a high level of Zn in its young seedling. It was observed that in most of the genotypes (seeds), K and Fe concentrations were more in the tolerant genotype as compared to the susceptible type. The concentration of Fe decreased with maturity in the tolerant group and it increased with maturity in the susceptible group.

Spontaneous rupture of spleen in falciparum malaria.

Spontaneous rupture of spleen is an extremely rare complication of falciparum malaria. We report a 3 1/2-year-old girl with splenic rupture who was managed successfully with splenectomy and antimalarials.

AN EPIDEMIOLOGICAL STUDY OF BLOOD PRESSURE AMONG SCHOOL CHILDREN.

Blood pressure was measured in 1170 school children between 5 and 15 years of age. Mean blood pressure was significantly higher in boys than girls in all age groups and a steady increase in blood pressure with age was seen in both the sexes. Mean blood pressure was significantly higher among children with positive family history of cardiovascular morbidity. Children from higher socio-economic strata and overweight children also showed higher blood pressure. Nine (0.77%) children had persistent hypertension. However, the degree of hypertension was mild and all these children were asymptomatic. Baseline investigations failed to detect any underlying pathology or target organ involvement. This study suggests that childhood could be a reasonably profitable time to look for such factors and to selectively screen children belonging to the high risk group for hypertension.

Synthesis of embedded Au nanostructures by ion irradiation: influence of ion induced viscous flow and sputtering.

The ion-irradiation induced synthesis of embedded Au nanoparticles (NPs) into glass from islands of Au on a glass substrate is studied in the context of recoiling atoms, sputtering and viscous flow. Cross sectional transmission electron microscopy studies revealed the formation of Au NPs embedded in the glass substrates by the 50 keV Si(-) ion irradiation of irregularly shaped Au nanostructures on the glass surfaces at a fluence of 3 × 10(16) ions/cm(2). The depth profiles of Au in the samples were obtained from high-resolution Rutherford backscattering spectrometry studies. The results from TRIDYN simulation reveal the role of various ion-induced processes during the synthesis of the embedded Au NPs, viz. sputtering and recoiling atoms. Simulation and experimental results suggest that the viscous flow is one of the major factors that are responsible for the embedding of Au nanoparticles into the glass substrate.

Measurement of direct photon production in p+p collisions at sqrt[s] = 200 GeV.

Cross sections for midrapidity production of direct photons in p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are reported for transverse momenta of 3 < pT < 16 GeV/c. Next-to-leading order perturbative QCD (pQCD) describes the data well for pT >5 GeV/c, where the uncertainties of the measurement and theory are comparable. We also report on the effect of requiring the photons to be isolated from parton jet energy. The observed fraction of isolated photons is well described by pQCD for pT >7 GeV/c.