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We report on measurements of dielectron (e + e − ) production in Au+Au collisions at a centerof-mass energy of 200 GeV per nucleon-nucleon pair using the STAR detector at RHIC. Systematic measurements of the dielectron yield as a function of transverse momentum (pT) and collision centrality show an enhancement compared to a cocktail simulation of hadronic sources in the low invariant-mass region (Mee < 1 GeV/c 2 ). This enhancement cannot be reproduced by the ρ-meson vacuum spectral function. In minimum-bias collisions, in the invariant-mass range of 0.30 − 0.76 GeV/c 2 , integrated over the full pT acceptance, the enhancement factor is 1.76 ± 0.06 (stat.) ± 0.26 (sys.) ± 0.29 (cocktail). The enhancement factor exhibits weak centrality and pT dependence in STAR's accessible kinematic regions, while the excess yield in this invariantmass region as a function of the number of participating nucleons follows a power-law shape with a power of 1.44 ± 0.10. Models that assume an in-medium broadening of the ρ meson spectral function consistently describe the observed excess in these measurements. Additionally, we report on measurements of ω and φ-meson production through their e + e − decay channel. These measurements show good agreement with Tsallis Blast-Wave model predictions as well as, in the case of the φ-meson, results through its K + K − decay channel. In the intermediate invariant-mass region (1.1< Mee < 3 GeV/c 2 ), we investigate the spectral shapes from different collision centralities. 3Physics implications for possible in-medium modification of charmed hadron production and other physics sources are discussed.

We report a new high-precision measurement of the mid-rapidity inclusive jet longitudinal doublespin asymmetry, ALL, in polarized pp collisions at center-of-mass energy √ s = 200 GeV. The STAR

For the first time a principle-component analysis is used to separate out different orthogonal modes of the two-particle correlation matrix from heavy ion collisions. The analysis uses data from √ s NN = 2.76 TeV PbPb and √ s NN = 5.02 TeV pPb collisions collected by the CMS experiment at the LHC. Two-particle azimuthal correlations have been extensively used to study hydrodynamic flow in heavy ion collisions. Recently it has been shown that the expected factorization of two-particle results into a product of the constituent single-particle anisotropies is broken. The new information provided by these modes may shed light on the breakdown of flow factorization in heavy ion collisions. The first two modes ("leading" and "subleading") of two-particle correlations are presented for elliptical and triangular anisotropies in PbPb and pPb collisions as a function of p T over a wide range of event activity. The leading mode is found to be essentially equivalent to the anisotropy harmonic previously extracted from two-particle correlation methods. The subleading mode represents a new experimental observable and is shown to account for a large fraction of the factorization breaking recently observed at high transverse momentum. The principle-component analysis technique has also been applied to multiplicity fluctuations. These also show a subleading mode. The connection of these new results to previous studies of factorization is discussed.