WG2 (NUCLEAR PHYSICS) ACTIVITIES IN 2016

During 2016 there were 4 collocated Working Group 2 Meetings.

The first meeting was allocated within the workshop “Pulsars and their environments”
that took place in the Observatory of Paris in Meudon (France) from May 18th to 20th 2016 which counted with 63 participants. The WG meeting was organized on the afternoon of May 20th and was chaired by the previous WG2 leader Jerôme Margeron. The meeting consisted on a discussion on the topic ” Microscopic needs for compact stars physics” chaired by Niels Andersson, Nikolaos Stergioulas and Stefan Typel followed by 4 presentations made by two of the four Topic Leaders of the WG2 and two participants.
These presentations were:

– Proving nuclear superfluidity with pulsar timing observations (Nicolas Chamel, TL)
– Nuclear symmetry energy and the r-mode instability of neutron stars (Isaac Vidana,TL)
– Extended Skyrme equation of state in asymmetric nuclear matter (Pierre Becker)
– A novel mapping of the non-local Fock terms onto the relativistic Hartree theory (Kristian Petrik)

The second WG2 meeting took place during the conference “Compact stars in the QCD phase diagram V” that was held in the Laboratorio Nazionale del Gran Sasso (L’Acquila, Italy) during the days May 23d-27th 2016 which counted with 55 participants. The WG2 meeting was done on the afternoon of May 26th and was chaired by the Topic Leader Laura Tolos. The meeting consisted on a short introduction of NewCompstar and the WG2 made by Laura Tolos followed by 4 presentations and a round table where there was a lively discussion on the topics of the presentations, mainly centered on phase transitions in neutron stars and their observational features. The 4 presentations were:

– Chiral symmetry and deconfinement: consequences for compact star physics (Matthias Hempel)
– Pulsar differential rotation with superfluid entrainment (Marco Antonelli)
– Cooling and rotational dynamics of compact stars (Armen Sedrakian)
– Simultaneous chiral symmetry restoration an deconfinement: consequences for the QCD phase diagram

Participants of previous editions of this conference were aware of the activities of NewCompstar.

The third WG2 meeting was done during the conference “Critical Point and Onset of Deconfinement 2016″ that was help in Wroclaw (Poland) from May 30th till June 14th 2016 and joint 100 participants. The WG2 meeting, entitled ” QCD phases and observable neutron star properties” was organized during the afternoon of May 31st and was chair by the Topic Leader Gergely Barnafoldi and consisted on 7 presentations followed by an open and free discussion on how QCD-theory and heavy-ion experiments can support dense matter EoS models for compact stars. The presentations were

– Recent progress in the EoS for NewCompstar (Gergely Barnafoldi, TL)
– Quarks in neutron stars (Gordon Baym)
– Cooling of neutron stars with stiff stellar matter (Hovik Grigorian)
– Consequences of simultaneous chiral symmetry restoration and deconfinement for the QCD phase diagram (Thomas Klahn)
– QCD in stars (Toru Kojo)
– Bayesian analysis for new class of hybrid star EoS with M-R observations for neutron stars (Alezandre Ayriyan)

The organizers of the conference highlighted the ignition- and motivate-being of the WG2 session for the rest
of the conference.

The last WG2 meeting was organized within the meeting “Brainstorming on compact star objects, their equation of state” that was help in Basel (Switzerland) from September 29th till October 1st 2016. This meeting counted with 60 participants and its scope was to discuss the status and open problems on stellar objects, their evolution,
explosions and nucleosynthesis in relation with nuclear physics. A special focus was put on the role of the nuclear EoS. The meeting consisted on 15 minutes talks followed by discussions. On the last day there were paralel sessions on

– EoS & compact stars (chaired by Matthias Hempel)
– Other nuclear/neutrino physics aspects affecting explosive events (chaired by Gabriel Martinez-Pinedo& I. Panov)
– Nucleosyntesis and its impact on galactic evolution (chaired by C: Kobayashi & F. Matteuci)

Finally a general discussion and a particular discussion

In addition to these meetings several WG2 members participated in other WG meetings like the meeting “Oscillations and Instabilities in Neutron Stars” a WG1-WG3 meeting that was held in Southampton (UK) in September 13th-14th 2016.

Finally 7 of the Short Term Scientific Missions awarded in 2016 were related with the scientific interests of the WG2.