Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Overview of recent results from the STAR experiment   The Solenoidal Tracker at RHIC (STAR) experiment utilizes its excellent
mid-rapidity tracking and particle identification capabilities to study the
emergent properties of Quantum Chromodynamics (QCD). The STAR heavy-ion program
at vanishingly small baryon density is aimed to address questions about the
quantitative properties of the strongly-interacting Quark Gluon Plasma (QGP)
matter created in high energy collisions ($\eta/s$, $\hat{q}$, chirality,
transport parameters, heavy quark diffusion coefficients ...). At finite baryon
density, the questions concern the phases of nuclear matter (the QCD phase
diagram) and the nature of the phase transition, namely: what is the onset
collision energy for the formation of QGP? What is the nature of phase
transition in heavy-ion collisions? Are there two phase transition regions? If
yes, where is the critical point situated? At Quark Matter 2015, the STAR
collaboration has presented a wealth of new experimental results which address
these questions. In these proceedings I highlight a few of those results.

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The categories of this paper are: astro-ph
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The categories of this paper are: supr-con
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The categories of this paper are: cond-mat
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The categories of this paper are: quant-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: hep-ex
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The categories of this paper are: math
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The categories of this paper are: alg-geom
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The categories of this paper are: solv-int
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The categories of this paper are: math-ph
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The categories of this paper are: nlin
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The categories of this paper are: atom-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: bayes-an
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The categories of this paper are: ao-sci
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The categories of this paper are: econ