Azimuthal angle ({delta}{phi}) correlations are presented for a broad range of transverse momentum (0.4<p{sub T}<10 GeV/c) and centrality (0-92%) selections for charged hadrons from dijets in Au+Au ...collisions at {radical}(s{sub NN})=200 GeV. With increasing p{sub T}, the away-side {delta}{phi} distribution evolves from a broad and relatively flat shape to a concave shape, then to a convex shape. Comparisons with p+p data suggest that the away-side distribution can be divided into a partially suppressed 'head' region centered at {delta}{phi}{approx}{pi}, and an enhanced 'shoulder' region centered at {delta}{phi}{approx}{pi}{+-}1.1. The p{sub T} spectrum for the associated hadrons in the head region softens toward central collisions. The spectral slope for the shoulder region is independent of centrality and trigger p{sub T}. The properties of the near-side distributions are also modified relative to those in p+p collisions, reflected by the broadening of the jet shape in {delta}{phi} and {delta}{eta}, and an enhancement of the per-trigger yield. However, these modifications seem to be limited to p{sub T} < or approx. 4 GeV/c, above which both the hadron pair shape and per-trigger yield become similar to p+p collisions. These observations suggest that both the away- and near-side distributions contain a jet fragmentation component which dominates for p{sub T} > or approx. 5 GeV/c and a medium-induced component which is important for p{sub T} < or approx. 4 GeV/c. We also quantify the role of jets at intermediate and low p{sub T} through the yield of jet-induced pairs in comparison with binary scaled p+p pair yield. The yield of jet-induced pairs is suppressed at high pair proxy energy (sum of the p{sub T} magnitudes of the two hadrons) and is enhanced at low pair proxy energy. The former is consistent with jet quenching; the latter is consistent with the enhancement of soft hadron pairs due to transport of lost energy to lower p{sub T}.
We investigated the relationship between maintenance costs (standard metabolic rates, measured as O2consumption at rest) in tadpoles of the bullfrog,Rana catesbeiana, and exposure to contaminants in ...a coal ash‐polluted habitat (characterized by a variety of trace elements). We compared metabolic rates of tadpoles collected from the polluted site with those from an unpolluted reference pond. Tadpoles collected in the polluted site had 40%–97% higher standard metabolic rates than those collected from the reference pond. We also reciprocally transplanted eggs of the bullfrog between the polluted site and another reference pond and compared standard metabolic rates of tadpoles at 25 and 80 d posthatching. Metabolic rates of tadpoles raised in the polluted site were from 39% to 175% higher than those raised in a reference pond, depending on tadpole age and temperature at which metabolic rates were measured. There were no effects of site of origin of the eggs (polluted or unpolluted) on metabolic rates. Survival to hatching did not differ between sites, although survival to the end of the experiment (80 d posthatching) was lower in the polluted area than in the reference site. Surviving tadpoles were larger in wet body mass in the polluted site than in the reference pond, possibly due to lower survival in the former, but there was no relationship between survival and metabolic rate. It is clear that some feature of the polluted habitat was responsible for causing substantial elevation of standard metabolic rates of tadpoles. We hypothesize that the mixture of trace elements present in sediment and water in the polluted site was responsible for the observed physiological differences.
The azimuthal anisotropy coefficients v_2 and v_4 of pi^0 and eta mesons are measured in Au+Au collisions at sqrt(s_NN)=200 GeV, as a function of transverse momentum p_T (1-14 GeV/c) and centrality. ...The extracted v_2 coefficients are found to be consistent between the two meson species over the measured p_T range. The ratio of v_4/v_2^2 for pi^0 mesons is found to be independent of p_T for 1-9 GeV/c, implying a lack of sensitivity of the ratio to the change of underlying physics with p_T. Furthermore, the ratio of v_4/v_2^2 is systematically larger in central collisions, which may reflect the combined effects of fluctuations in the initial collision geometry and finite viscosity in the evolving medium.
The field of relativistic heavy ion physics has seen significant advancement in the new millennium toward a greater understanding of QCD at high temperatures with the commissioning and operation of ...the Relativistic Heavy Ion Collider. Here we review progress in the field as presented in a set of lectures at the Lake Louise Winter Institute on Fundamental Interactions in February 2004.
The PHENIX experiment has measured the suppression of semi-inclusive single high-transverse-momentum {pi}{sup 0}'s in Au+Au collisions at {radical}(s{sub NN})=200 GeV. The present understanding of ...this suppression is in terms of energy loss of the parent (fragmenting) parton in a dense color-charge medium. We have performed a quantitative comparison between various parton energy-loss models and our experimental data. The statistical point-to-point uncorrelated as well as correlated systematic uncertainties are taken into account in the comparison. We detail this methodology and the resulting constraint on the model parameters, such as the initial color-charge density dN{sup g}/dy, the medium transport coefficient <q-circumflex>, or the initial energy-loss parameter {epsilon}{sub 0}. We find that high-transverse-momentum {pi}{sup 0} suppression in Au+Au collisions has sufficient precision to constrain these model-dependent parameters at the {+-}20-25% (one standard deviation) level. These constraints include only the experimental uncertainties, and further studies are needed to compute the corresponding theoretical uncertainties.
Nonselective and beta 1-selective adrenergic antagonists were tested for their effects on enzymatic adaptation to exercise training in rats as follows: trained + placebo (TC); trained + propranolol ...(TP); trained + atenolol (TA); and corresponding sedentary groups, SC and SP. Trained rats ran 1 h/d at 26.8 m/min, 15% grade, 5 d/wk, 10 wk. Both beta-antagonists were given at doses that decreased exercise heart rates by 25%. Training increased skeletal muscle citrate synthase, cytochrome c oxidase (Cyt-Ox), carnitine palmitoyltransferase (CPT), beta-hydroxyacyl coenzyme A dehydrogenase, mitochondrial malate dehydrogenase (MDH), and alanine aminotransferase (ALT) activities significantly in the TC group, but not in TP. These enzyme activities, except Cyt-Ox and CPT, were also significantly increased in TA. Hepatic phosphoenolpyruvate carboxykinase activity did not alter with training or beta-blockade. Fructose 1,6-bisphosphatase activity was lower in TC than in SC, but unchanged in TP or TA. Hepatic mitochondrial MDH and ALT activities increased with training only in TC. It is concluded that beta 2-adrenergic mechanisms play an essential role in the training-induced enzymatic adaptation in skeletal muscle.
Measurements of transverse-single-spin asymmetries ($A_{N}$) in $p$$+$$p$
collisions at $\sqrt{s}=$62.4 and 200 GeV with the PHENIX detector at RHIC are
presented. At midrapidity, $A_{N}$ is measured ...for neutral pion and eta mesons
reconstructed from diphoton decay, and at forward rapidities, neutral pions are
measured using both diphotons and electromagnetic clusters. The neutral-pion
measurement of $A_{N}$ at midrapidity is consistent with zero with
uncertainties a factor of 20 smaller than previous publications, which will
lead to improved constraints on the gluon Sivers function. At higher
rapidities, where the valence quark distributions are probed, the data exhibit
sizable asymmetries. In comparison with previous measurements in this kinematic
region, the new data extend the kinematic coverage in $\sqrt{s}$ and $p_T$, and
it is found that the asymmetries depend only weakly on $\sqrt{s}$. The origin
of the forward $A_{N}$ is presently not understood quantitatively. The extended
reach to higher $p_T$ probes the transition between transverse momentum
dependent effects at low $p_T$ and multi-parton dynamics at high $p_T$.
Phys. Rev. C. 89, 034915 (2014) We report $e^\pm-\mu^\mp$ pair yield from charm decay measured between
midrapidity electrons ($|\eta|<0.35$ and $p_T>0.5$ GeV/$c$) and forward
rapidity muons ...($1.4<\eta<2.1$ and $p_T>1.0$ GeV/$c$) as a function of
$\Delta\phi$ in both $p$$+$$p$ and in $d$+Au collisions at
$\sqrt{s_{_{NN}}}=200$ GeV. Comparing the $p$$+$$p$ results with several
different models, we find the results are consistent with a total charm cross
section $\sigma_{c\bar{c}} =$ 538 $\pm$ 46 (stat) $\pm$ 197 (data syst) $\pm$
174 (model syst) $\mu$b. These generators also indicate that the back-to-back
peak at $\Delta\phi = \pi$ is dominantly from the leading order contributions
(gluon fusion), while higher order processes (flavor excitation and gluon
splitting) contribute to the yield at all $\Delta\phi$. We observe a
suppression in the pair yield per collision in $d$+Au. We find the pair yield
suppression factor for $2.7<\Delta\phi<3.2$ rad is $J_{dA}$ = 0.433 $\pm$ 0.087
(stat) $\pm$ 0.135 (syst), indicating cold nuclear matter modification of
$c\bar{c}$ pairs.
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