12143325
Constraints on Jupiters from observations of Galactic Bulge microlensing events during 2000.
We present observations of 8 Galactic Bulge microlensing events taken with the 1.0m JKT on La Palma during 2000 June and July. The JKT observing schedule was optimized using a prioritizing algorithm to automatically update the target list. For most of these events we have sampled the lightcurves at times where no information was available from the OGLE alert team. We assume a point-source point-lens (PSPL) model and perform a maximum likelihood fit to both our data and the OGLE data to constrain the event parameters of the fit. We then refit the data assuming a binary lens and proceed to calculate the probability of detecting planets with mass ratio q = 10 3 . We have seen no clear signatures of planetary deviations on any of the 8 events and we quantify constraints on the presence of planetary companions to the lensing stars. For two well observed events, 2000BUL31 and 2000BUL33, our detection probabilities
46522188
The spin-orbit angles of the transiting exoplanets WASP-1b, WASP-24b, WASP-38b and HAT-P-8b from Rossiter–McLaughlin observations
We present observations of the Rossiter-McLaughlin effect for the transiting exoplanet systems WASP-1, WASP-24, WASP-38 and HAT-P-8, and deduce the orientations of the planetary orbits with respect to the host stars’ rotatio n axes. The planets WASP-24b, WASP-38b and HAT-P-8b appear to move in prograde orbits and be well aligned, having sky-projected spin orbit angles consistent with zero: � = 4:7 ± 4:0 � , � =15 +33 � −43� and� = 9:7 +9.0 � −7.7� , respectively. The host stars have Teff < 6250 K and conform with the trend of cooler stars having low obliquities. WASP-38b is a massive planet on a moderately long period, eccentric orbit so may be expected to have a misaligned orbit given the high obliquities measured in similar systems. However, we find no evidence for a large spinorbit angle. By contrast, WASP-1b joins the growing number of misaligned systems and has an almost polar orbit, � = 79:0 +4.5 � −4.3� . It is neither very massive, eccentric nor orbiting a hot host star, and therefore does not share the properties of many other misaligned systems.
15479457
Resonance decay effects on anisotropy parameters
We present the elliptic flow v{sub 2} of pions produced from resonance decays. The transverse momentum p{sub T} spectra of the parent particles are taken from thermal model fits and their v{sub 2} are fit under the assumption that they follow a number-of-constituent-quark (NCQ) scaling law expected from quark-coalescence models. The v{sub 2} of pions from resonance particle decays is found to be similar to the measured pion v{sub 2}. We also propose the measurement of electron v{sub 2} as a means to extract open-charm v{sub 2} and investigate whether a thermalized system of quasi-free quarks and gluons (a quark-gluon plasma) is created in collisions of Au nuclei at RHIC.
117083860
Finite-size effects and the search for the critical endpoint of QCD
Taking into account the finiteness of the system created in heavy ion collisions, we show sizable results for the modifications of the chiral phase diagram at volume scales typically encountered in current experiments and demonstrate the applicability of finite-size scaling as a tool in the experimental search for the critical endpoint. Using data from RHIC and SPS and assuming finite-size scaling, we find that RHIC data from 200 GeV down to 19.6 GeV is only consistent with a critical point at \mu \gtrsim 510 MeV. We also present predictions for the fluctuations at lower energies currently being investigated in the Beam Energy Scan program.
119255314
Azimuthal anisotropy in U+U collisions at STAR
Abstract The azimuthal anisotropy of particle production is commonly used in high-energy nuclear collisions to study the early evolution of the expanding system. The prolate shape of uranium nuclei makes it possible to study how the geometry of the colliding nuclei affects final state anisotropies. It also provides a unique opportunity to understand how entropy is produced in heavy-ion collisions. In this paper, the two- and four-particle cumulant v 2 ( v 2 { 2 } and v 2 { 4 } ) from U+U collisions at s NN = 193 GeV and Au+Au collisions at s NN = 200 GeV for inclusive charged hadrons will be presented. The STAR Zero Degree Calorimeters are used to select very central collisions. Differences were observed between the multiplicity dependence of v 2 { 2 } for most central Au+Au and U+U collisions. The multiplicity dependence of v 2 { 2 } in central collisions was compared to Monte Carlo Glauber model predictions and it was seen that this model cannot explain the present results.
119106969
A coherent understanding of low-energy nuclear recoils in liquid xenon
Liquid xenon detectors such as XENON10 and XENON100 obtain a significant fraction of their sensitivity to light (10 GeV) particle dark matter by looking for nuclear recoils of only a few keV, just above the detector threshold. Yet in this energy regime a correct treatment of the detector threshold and resolution remains unclear. The energy dependence of the scintillation yield of liquid xenon for nuclear recoils also bears heavily on detector sensitivity, yet numerous measurements have not succeeded in obtaining concordant results. In this article we show that the ratio of detected ionization to scintillation can be leveraged to constrain the scintillation yield. We also present a rigorous treatment of liquid xenon detector threshold and energy resolution. Notably, the effective energy resolution differs significantly from a simple Poisson distribution. We conclude with a calculation of dark matter exclusion limits, and show that existing data from liquid xenon detectors strongly constrain recent interpretations of light dark matter.
119279858
The Rise and Fall of the Ridge
Abstract Recent data from heavy ion collisions at RHIC show unexpectedly large near-angle correlations that broaden longitudinally with centrality. The amplitude of this ridge-like correlation rises rapidly with centrality, reaches a maximum, and then falls in the most central collisions. In this talk we explain how this behavior can be easily understood in a picture where final momentum-space correlations are driven by initial coordinate space density fluctuations. We propose ν n 2 / e n , part 2 as a useful way to study these effects and explain what it tells us about the collision dynamics.