Preface: CSQCDIX

Abstract

The 9th international workshop Compact Stars in the QCD phase diagram was held, during August 1-5 2022, in Banff (Alberta, Canada) entitled “Compact Stars in the QCD phase diagram IX (CSQCD IX): From RHIC to Astrophysics, Probing the Quark-Gluon Plasma”. This series of meetings started in 2001 in Copenhagen (Denmark), and then continued in 2009 in Beijing (China), 2012 in Guaruja (Brazil), 2014 in Prerow (Germany), 2016 in l’Aquila (Italy), 2017 in Dubna (Russia), 2018 in New York (NY, USA), and 2020 at ICTS (India; on line).The CSQCD workshops aim to bring together physicists working on strongly interacting dense matter with astrophysicists working on Compact Stars and related astrophysical phenomena such as supernovae, gamma ray bursts and pulsars. A profound theoretical description of these astrophysical phenomena necessarily involves the equation of state and transport properties of QCD matter that are derived from non-perturbative quantum field theories, many-body physics of strongly interacting matter and phenomenological investigations. CSQCD IX focussed on recent explorations of the quark-gluon phase using colliders (e.g. RHIC and LHC) and on the renewed interest in neutron and quark matter in astrophysics, particularly in the gravitational wave era.The science sessions focused on nuclear matter at high baryon density, on probing neutron-star matter in the laboratory, and on explorations of characterization of the critical endpoint in the nuclear matter phase diagram. The phases and the equation of state was discussed (in memory of Stefan Schramm) as well as transport phenomena in compact stars. Recent results constraining the nuclear symmetry energy from experiments, theory and observations and implications for compact stars were also presented. For the first time in the CSQCD series, talks highlighted the importance of gravitational waves as: (i) a tool to probe compact stars and QCD phase transitions; (ii) as probes of reacting interfaces in the core of neutron stars. Also featured were recent data from NICER and implications on neutron stars as well as neutron star mergers as materials science.The present volume of the Journal of Physics: Conference Series represents selected contributions from the participants of the CSQCD IX workshop. Each submitted contribution has been peer reviewed and the Editors are very grateful to the referees for their careful support.The Editors of the CSQCD IX Proceedings:Rachid Ouyed (University of Calgary, Canada)Denis Leahy (University of Calgary, Canada)Nico Koning (University of Calgary, Canada)Tobias Fischer (University of Wroclaw, Poland)Sumiyoshi Kohsuke (National Institute of Technology, Numazu College, Japan)Massimo Mannarelli (National Laboratories of Gran Sasso, Italy)Fridolin Weber (San Diego State University, USA)Calgary, 1st of May 2023