We present estimates of line-of-sight distortion fields derived from the 95 GHz and 150 GHz data taken by BICEP2, BICEP3, and Keck Array up to the 2018 observing season, leading to cosmological ...constraints and a study of instrumental and astrophysical systematics. Cosmological constraints are derived from three of the distortion fields concerning gravitational lensing from large-scale structure, polarization rotation from magnetic fields or an axion-like field, and the screening effect of patchy reionization. We measure an amplitude of the lensing power spectrum \(A_L^{\phi\phi}=0.95 \pm 0.20\). We constrain polarization rotation, expressed as the coupling constant of a Chern-Simons electromagnetic term \(g_{a\gamma} \leq 2.6 \times 10^{-2}/H_I\), where \(H_I\) is the inflationary Hubble parameter, and an amplitude of primordial magnetic fields smoothed over 1 Mpc \(B_{1\text{Mpc}} \leq 6.6 \;\text{nG}\) at 95 GHz. We constrain the root mean square of optical-depth fluctuations in a simple "crinkly surface" model of patchy reionization, finding \(A^\tau<0.19\) (\(2\sigma\)) for the coherence scale of \(L_c=100\). We show that all of the distortion fields of the 95 GHz and 150 GHz polarization maps are consistent with simulations including lensed-\(\Lambda\)CDM, dust, and noise, with no evidence for instrumental systematics. In some cases, the EB and TB quadratic estimators presented here are more sensitive than our previous map-based null tests at identifying and rejecting spurious B-modes that might arise from instrumental effects. Finally, we verify that the standard deprojection filtering in the BICEP/Keck data processing is effective at removing temperature to polarization leakage.
Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct ...photons in p↑ + p collisions at √s = 200 GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a 50-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.
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(Abridged) We present the results of an X-ray analysis of 80 galaxy clusters selected in the 2500 deg^2 South Pole Telescope survey and observed with the Chandra X-ray Observatory. We divide the full ...sample into subsamples of ~20 clusters based on redshift and central density, performing an X-ray fit to all clusters in a subsample simultaneously, assuming self-similarity of the temperature profile. This approach allows us to constrain the shape of the temperature profile over 0<r<1.5R500, which would be impossible on a per-cluster basis, since the observations of individual clusters have, on average, 2000 X-ray counts. The results presented here represent the first constraints on the evolution of the average temperature profile from z=0 to z=1.2. We find that high-z (0.6<z<1.2) clusters are slightly (~40%) cooler both in the inner (r<0.1R500) and outer (r>R500) regions than their low-z (0.3<z<0.6) counterparts. Combining the average temperature profile with measured gas density profiles from our earlier work, we infer the average pressure and entropy profiles for each subsample. Overall, our observed pressure profiles agree well with earlier lower-redshift measurements, suggesting minimal redshift evolution in the pressure profile outside of the core. We find no measurable redshift evolution in the entropy profile at r<0.7R500. We observe a slight flattening of the entropy profile at r>R500 in our high-z subsample. This flattening is consistent with a temperature bias due to the enhanced (~3x) rate at which group-mass (~2 keV) halos, which would go undetected at our survey depth, are accreting onto the cluster at z~1. This work demonstrates a powerful method for inferring spatially-resolved cluster properties in the case where individual cluster signal-to-noise is low, but the number of observed clusters is high.
We present a measurement of the \(B\)-mode polarization power spectrum (the \(BB\) spectrum) from 100 \(\mathrm{deg}^2\) of sky observed with SPTpol, a polarization-sensitive receiver currently ...installed on the South Pole Telescope. The observations used in this work were taken during 2012 and early 2013 and include data in spectral bands centered at 95 and 150 GHz. We report the \(BB\) spectrum in five bins in multipole space, spanning the range \(300 \le \ell \le 2300\), and for three spectral combinations: 95 GHz \(\times\) 95 GHz, 95 GHz \(\times\) 150 GHz, and 150 GHz \(\times\) 150 GHz. We subtract small (\(< 0.5 \sigma\) in units of statistical uncertainty) biases from these spectra and account for the uncertainty in those biases. The resulting power spectra are inconsistent with zero power but consistent with predictions for the \(BB\) spectrum arising from the gravitational lensing of \(E\)-mode polarization. If we assume no other source of \(BB\) power besides lensed \(B\) modes, we determine a preference for lensed \(B\) modes of \(4.9 \sigma\). After marginalizing over tensor power and foregrounds, namely polarized emission from galactic dust and extragalactic sources, this significance is \(4.3 \sigma\). Fitting for a single parameter, \(A_\mathrm{lens}\), that multiplies the predicted lensed \(B\)-mode spectrum, and marginalizing over tensor power and foregrounds, we find \(A_\mathrm{lens} = 1.08 \pm 0.26\), indicating that our measured spectra are consistent with the signal expected from gravitational lensing. The data presented here provide the best measurement to date of the \(B\)-mode power spectrum on these angular scales.
We characterize Galactic dust filaments by correlating BICEP/Keck and Planck data with polarization templates based on neutral hydrogen (H I) observations. Dust polarization is important for both our ...understanding of astrophysical processes in the interstellar medium (ISM) and the search for primordial gravitational waves in the cosmic microwave background (CMB). In the diffuse ISM, H I is strongly correlated with the dust and partly organized into filaments that are aligned with the local magnetic field. We analyze the deep BICEP/Keck data at 95, 150, and 220 GHz, over the low-column-density region of sky where BICEP/Keck has set the best limits on primordial gravitational waves. We separate the H I emission into distinct velocity components and detect dust polarization correlated with the local Galactic H I but not with the H I associated with Magellanic Stream I. We present a robust, multifrequency detection of polarized dust emission correlated with the filamentary H I morphology template down to 95 GHz. For assessing its utility for foreground cleaning, we report that the H I morphology template correlates in B modes at a \(\sim\)10-65\(\%\) level over the multipole range \(20 < \ell < 200\) with the BICEP/Keck maps, which contain contributions from dust, CMB, and noise components. We measure the spectral index of the filamentary dust component spectral energy distribution to be \(\beta = 1.54 \pm 0.13\). We find no evidence for decorrelation in this region between the filaments and the rest of the dust field or from the inclusion of dust associated with the intermediate velocity H I. Finally, we explore the morphological parameter space in the H I-based filamentary model.
We present a catalog of galaxy clusters selected via their Sunyaev-Zel'dovich (SZ) effect signature from 2500 deg\(^2\) of South Pole Telescope (SPT) data. This work represents the complete sample of ...clusters detected at high significance in the 2500-square-degree SPT-SZ survey, which was completed in 2011. A total of 677 (409) cluster candidates are identified above a signal-to-noise threshold of \(\xi\) =4.5 (5.0). Ground- and space-based optical and near-infrared (NIR) imaging confirms overdensities of similarly colored galaxies in the direction of 516 (or 76%) of the \(\xi\)>4.5 candidates and 387 (or 95%) of the \(\xi\)>5 candidates; the measured purity is consistent with expectations from simulations. Of these confirmed clusters, 415 were first identified in SPT data, including 251 new discoveries reported in this work. We estimate photometric redshifts for all candidates with identified optical and/or NIR counterparts; we additionally report redshifts derived from spectroscopic observations for 141 of these systems. The mass threshold of the catalog is roughly independent of redshift above \(z\)~0.25 leading to a sample of massive clusters that extends to high redshift. The median mass of the sample is \(M_{\scriptsize 500c}(\rho_\mathrm{crit})\) ~ 3.5 x 10\(^{14} M_\odot h^{-1}\), the median redshift is \(z_{med}\) =0.55, and the highest-redshift systems are at \(z\)>1.4. The combination of large redshift extent, clean selection, and high typical mass makes this cluster sample of particular interest for cosmological analyses and studies of cluster formation and evolution.
Measurements of the differential production of electrons from open-heavy-flavor hadrons with charm- and bottom-quark content in p+p collisions at s=200 GeV are presented. The measurements proceed ...through displaced-vertex analyses of electron tracks from the semileptonic decay of charm and bottom hadrons using the PHENIX silicon-vertex detector. The relative contribution of electrons from bottom decays to inclusive heavy-flavor-electron production is found to be consistent with fixed-order-plus-next-to-leading-log perturbative-QCD calculations within experimental and theoretical uncertainties. These new measurements in p+p collisions provide a precision baseline for comparable forthcoming measurements in A+A collisions.
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Clusters of galaxies gravitationally lens the cosmic microwave background (CMB) radiation, resulting in a distinct imprint in the CMB on arcminute scales. Measurement of this effect offers a ...promising way to constrain the masses of galaxy clusters, particularly those at high redshift. We use CMB maps from the South Pole Telescope Sunyaev-Zel'dovich (SZ) survey to measure the CMB lensing signal around galaxy clusters identified in optical imaging from first year observations of the Dark Energy Survey. The cluster catalog used in this analysis contains 3697 members with mean redshift of \(\bar{z} = 0.45\). We detect lensing of the CMB by the galaxy clusters at \(8.1\sigma\) significance. Using the measured lensing signal, we constrain the amplitude of the relation between cluster mass and optical richness to roughly \(17\%\) precision, finding good agreement with recent constraints obtained with galaxy lensing. The error budget is dominated by statistical noise but includes significant contributions from systematic biases due to the thermal SZ effect and cluster miscentering.
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