We present measurements of \(E\)-mode polarization and temperature-\(E\)-mode correlation in the cosmic microwave background (CMB) using data from the first season of observations with SPTpol, the ...polarization-sensitive receiver currently installed on the South Pole Telescope (SPT). The observations used in this work cover 100~\sqdeg\ of sky with arcminute resolution at \(150\,\)GHz. We report the \(E\)-mode angular auto-power spectrum (\(EE\)) and the temperature-\(E\)-mode angular cross-power spectrum (\(TE\)) over the multipole range \(500 < \ell \leq5000\). These power spectra improve on previous measurements in the high-\(\ell\) (small-scale) regime. We fit the combination of the SPTpol power spectra, data from \planck\, and previous SPT measurements with a six-parameter \LCDM cosmological model. We find that the best-fit parameters are consistent with previous results. The improvement in high-\(\ell\) sensitivity over previous measurements leads to a significant improvement in the limit on polarized point-source power: after masking sources brighter than 50\,mJy in unpolarized flux at 150\,GHz, we find a 95\% confidence upper limit on unclustered point-source power in the \(EE\) spectrum of \(D_\ell = \ell (\ell+1) C_\ell / 2 \pi < 0.40 \ \mu{\mbox{K}}^2\) at \(\ell=3000\), indicating that future \(EE\) measurements will not be limited by power from unclustered point sources in the multipole range \(\ell < 3600\), and possibly much higher in \(\ell.\)
The PHENIX experiment at the Relativistic Heavy Ion Collider measured π0 and η mesons at midrapidity in U+U collisions at sNN=192 GeV in a wide transverse momentum range. Measurements were performed ...in the π0(η)→γγ decay modes. A strong suppression of π0 and η meson production at high transverse momentum was observed in central U+U collisions relative to binary scaled p+p results. Yields of π0 and η mesons measured in U+U collisions show similar suppression pattern to those measured in Au+Au collisions at sNN=200 GeV for similar numbers of participant nucleons. The η/π0 ratios do not show dependence on centrality or transverse momentum and are consistent with previously measured values in hadron-hadron, hadron-nucleus, nucleus-nucleus, and e+e- collisions.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
1 Cooperative Research Centre for Eye Research and Technology, University of New South Wales, 22–32 King Street, Randwick 2031, NSW, Australia
2 Corresponding author: Dr M. D. P. Willcox.
Received ...November 11, 1998
Accepted December 24, 1998
The cationic tear proteins lactoferrin and lysozyme exhibit co-operative antistaphylococcal properties. The purpose of this study was to determine the mechanism of action of this co-operation on Staphylococcus epidermidis . Following blocking of lipoteichoic acid (LTA) binding sites, the effects on binding of lactoferrin and susceptibility to lactoferrin and lysozyme were determined. The effect of lactoferrin on autolysis and LTA release was also examined. Maximal susceptibility occurred on addition of lactoferrin first followed by lysozyme. Blocking the LTA binding sites both reduced lactoferrin binding and decreased susceptibility. Autolytic activity decreased and LTA release increased in the presence of lactoferrin. These results suggest that binding of lactoferrin to LTA is important in its synergy with lysozyme and interferes with the autolysins present on the LTA. It is proposed that, on binding to the anionic LTA of S. epidermidis , the cationic protein lactoferrin decreases the negative charge, allowing greater accessibility of lysozyme to the underlying peptidoglycan.
We present a measurement of the angular bispectrum of the millimeter-wave sky in observing bands centered at roughly 95, 150, and 220 GHz, on angular scales of \(1^\prime \lesssim \theta \lesssim ...10^\prime\) (multipole number \(1000 \lesssim l \lesssim 10000\)). At these frequencies and angular scales, the main contributions to the bispectrum are expected to be the thermal Sunyaev-Zel'dovich (tSZ) effect and emission from extragalactic sources, predominantly dusty, star-forming galaxies (DSFGs) and active galactic nuclei. We measure the bispectrum in 800 \(\mathrm{deg}^2\) of three-band South Pole Telescope data, and we use a multi-frequency fitting procedure to separate the bispectrum of the tSZ effect from the extragalactic source contribution. We simultaneously detect the bispectrum of the tSZ effect at \(>\)10\(\sigma\), the unclustered component of the extragalactic source bispectrum at \(>\)5\(\sigma\) in each frequency band, and the bispectrum due to the clustering of DSFGs---i.e., the clustered cosmic infrared background (CIB) bispectrum---at \(>\)5\(\sigma\). This is the first reported detection of the clustered CIB bispectrum. We use the measured tSZ bispectrum amplitude, compared to model predictions, to constrain the normalization of the matter power spectrum to be \(\sigma_8 = 0.787 \pm 0.031\) and to predict the amplitude of the tSZ power spectrum at \(l = 3000\). This prediction improves our ability to separate the thermal and kinematic contributions to the total SZ power spectrum. The addition of bispectrum data improves our constraint on the tSZ power spectrum amplitude by a factor of two compared to power spectrum measurements alone and demonstrates a preference for a nonzero kinematic SZ (kSZ) power spectrum, with a derived constraint on the kSZ amplitude at \(l=3000\) of A_kSZ \( = 2.9 \pm 1.6 \ \mu\)K\(^2\), or A_kSZ \( = 2.6 \pm 1.8 \ \mu\)K\(^2\) if the default A_kSZ > 0 prior is removed.
The anisotropy parameter (v(2)), the second harmonic of the azimuthal particle distribution, has been measured with the PHENIX detector in Au+Au collisions at roots(NN)=200 GeV for identified and ...inclusive charged particle production at central rapidities (eta<0.35) with respect to the reaction plane defined at high rapidities (eta=3-4 ). We observe that the v(2) of mesons falls below that of (anti)baryons for p(T)>2 GeV/c, in marked contrast to the predictions of a hydrodynamical model. A quark-coalescence model is also investigated.
Full text
Available for:
CMK, CTK, FMFMET, IJS, NUK, PNG, UM
Phys. Rev. C 107, 024914 (2023) The measurement of direct photons from Au$+$Au collisions at
$\sqrt{s_{_{NN}}}=39$ and 62.4 GeV in the transverse-momentum range $0.4<p_T<3$
Gev/$c$ is presented by ...the PHENIX collaboration at the Relativistic Heavy Ion
Collider. A significant direct-photon yield is observed in both collision
systems. A universal scaling is observed when the direct-photon $p_T$ spectra
for different center-of-mass energies and for different centrality selections
at $\sqrt{s_{_{NN}}}=62.4$ GeV is scaled with $(dN_{\rm ch}/d\eta)^{\alpha}$
for $\alpha=1.21{\pm}0.04$. This scaling also holds true for direct-photon
spectra from Au$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV measured earlier
by PHENIX, as well as the spectra from Pb$+$Pb at $\sqrt{s_{_{NN}}}=2760$ GeV
published by ALICE. The scaling power $\alpha$ seems to be independent of
$p_T$, center of mass energy, and collision centrality. The spectra from
different collision energies have a similar shape up to $p_T$ of 2 GeV/$c$. The
spectra have a local inverse slope $T_{\rm eff}$ increasing with $p_T$ of
$0.174\pm0.018$ GeV/$c$ in the range $0.4<p_T<1.3$ GeV/$c$ and increasing to
$0.289\pm0.024$ GeV/$c$ for $0.9<p_T<2.1$ GeV/$c$. The observed similarity of
low-$p_T$ direct-photon production from $\sqrt{s_{_{NN}}}= 39$ to 2760 GeV
suggests a common source of direct photons for the different collision energies
and event centrality selections, and suggests a comparable space-time evolution
of direct-photon emission.
PDF
