Now showing items 185-204 of 1345

• #### Di-electron spectrum at mid-rapidity in p + p collisions at √ s = 200 GeV ﻿

(2012)
We report on the mid-rapidity mass spectrum of di-electrons and cross sections of pseudoscalar and vector mesons via e + e − decays, from √ s = 200 GeV p + p collisions, measured by the large-acceptance experiment STAR at ...
• #### Diagnosing the Time Dependence of Active Region Core Heating from the Emission Measure. II. Nanoflare Trains ﻿

(2013)
The time dependence of heating in solar active regions can be studied by analyzing the slope of the emission measure distribution coolward of the peak. In a previous study we showed that low-frequency heating can account for ...
• #### DIAGNOSING THE TIME-DEPENDENCE OF ACTIVE REGION CORE HEATING FROM THE EMISSION MEASURE. I. LOW-FREQUENCY NANOFLARES ﻿

(2012)
Observational measurements of active region emission measures contain clues to the time dependence of the underlying heating mechanism. A strongly nonlinear scaling of the emission measure with temperature indicates a large ...
• #### Dicke superradiance in solids [Invited] ﻿

(2016)
Recent advances in optical studies of condensed matter systems have led to the emergence of a variety of phenomena that have conventionally been studied in the realm of quantum optics. These studies have not only deepened ...
• #### Dielectron azimuthal anisotropy at mid-rapidity in Au + Au collisions at √sNN=200 GeV ﻿

(2014)
We report on the first measurement of the azimuthal anisotropy (v2) of dielectrons (e+e− pairs) at mid-rapidity from √sNN=200 GeV Au + Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), ...
• #### Dielectron Mass Spectra from Au+Au Collisions at √sNN=200  GeV ﻿

(2014)
We report the STAR measurements of dielectron (e+e−) production at midrapidity (|yee|<1) in Au+Au collisions at √sNN=200  GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30–0.76 ...
• #### Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s=7 eV ﻿

(2015)
Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse ...
• #### Dijet imbalance measurements in $\mathrm{Au}+\mathrm{Au}$ and $pp$ collisions at $\sqrt{{s}_{NN}}=200\text{ }\text{ }\mathrm{GeV}$ at STAR ﻿

(2017)
We report the first dijet transverse momentum asymmetry measurements from Au+Au and pp collisions at RHIC. The two highest-energy back-to-back jets reconstructed from fragments with transverse momenta above 2 GeV/c display ...
• #### Dilepton Production in p+p, Au+Au collisions at sNN=200GeV and U+U collisions at sNN=193GeV ﻿

(2017)
In this contribution we report e+e1 spectra with various invariant mass and pT differentials in Au+Au collisions at sNN=200GeV and U+U collisions at sNN=193GeV. The structure of the t (−t≈pT2) distributions of these mass ...
• #### Dipolar relaxation collisions in magnetically trapped 7Li ﻿

(1999)
We report the measurement of the rate constant for dipolar relaxation from the (F=2, mF=2) hyperfine state of 7Li. The atoms are confined in a permanent magnet trap at a field of 103 G. The measured value of (1.05±0.10)× ...
• #### Direct observation of growth and collapse of a Bose-Einstein condensate with attractive interactions ﻿

(2000)
Quantum theory predicts that Bose-Einstein condensation of a spatially homogeneous gas with attractive interactions is precluded by a conventional phase transition into either a liquid or solid [1]. When confined to a trap, ...
• #### Direct observation of magnon-phonon coupling in yttrium iron garnet ﻿

(2017)
The magnetic insulator yttrium iron garnet (YIG) with a ferrimagnetic transition temperature of ∼ 560 K has been widely used in microwave and spintronic devices. Anomalous features in spin Seeback effect (SSE) voltages ...
• #### Direct observation of spin excitation anisotropy in the paramagnetic orthorhombic state of BaFe2−xNixAs2 ﻿

(2018)
We use transport and inelastic neutron-scattering measurements to investigate single crystals of iron pnictide BaFe2−xNixAs2(x=0,0.03), which exhibit a tetragonal-to-orthorhombic structural transition at Ts and stripe ...
• #### Directed and elliptic flow of charged particles in Cu + Cu collisions at √sNN=22.4 GeV ﻿

(2012)
This paper reports results for directed flow v1 and elliptic flow v2 of charged particles in Cu + Cu collisions at √sNN=22.4 GeV at the Relativistic Heavy Ion Collider. The measurements are for the 0–60% most central ...
• #### Directed Flow of Identified Particles in Au+Au Collisions at √SNN=200  GeV at RHIC ﻿

(2012)
STAR’s measurements of directed flow (v1) around midrapidity for π±, K±, K0S, p, and p¯ in Au+Au collisions at √sNN=200  GeV are presented. A negative v1(y) slope is observed for most of produced particles (π±, K±, K0S, ...
• #### Discovery of a planetary-mass companion within the gap of the transition disk around PDS 70 ﻿

(2018)
Context. Young circumstellar disks are the birthplaces of planets. Their study is of prime interest to understand the physical and chemical conditions under which planet formation takes place. Only very few detections of ...
• #### Discovery of optimal zeolites for challenging separations and chemical transformations using predictive materials modeling ﻿

(2015)
Zeolites play numerous important roles in modern petroleum refineries and have the potential to advance the production of fuels and chemical feedstocks from renewable resources. The performance of a zeolite as separation ...
• #### Discrete Kinetic Models from Funneled Energy Landscape Simulations ﻿

(2012)
A general method for facilitating the interpretation of computer simulations of protein folding with minimally frustrated energy landscapes is detailed and applied to a designed ankyrin repeat protein (4ANK). In the method, ...

(2017)
• #### Dissipative transport of a Bose-Einstein condensate ﻿

(2010)
We investigate the effects of impurities, either correlated disorder or a single Gaussian defect, on the collective dipole motion of a Bose-Einstein condensate of Li7 in an optical trap. We find that this motion is damped ...