**Organizers:** Almudena Arcones, Jens Braun, Michael Buballa, Hans-Werner Hammer, Kai Hebeler, Gabriel Martínez-Pinedo, Daniel Mohler, Guy Moore, Robert Roth, Achim Schwenk, Jochen Wambach

**Time:** Tuesdays, 14:00 o'clock

**Place:** S2|11, Room 10

### WS 22/23

26.01.2023 14:00 via Zoom |
Dr. Zhonghao Sun (Oak Ridge National Laboratory)Ab-initio computation of exotic nucleiPrecise and predictive calculations of the atomic nuclei from realistic nuclear force help us to understand how the fundamental interaction leads to the emergence of various exotic phenomena. The advances in computational power, emerging machine learning technology, and the development of many-body methods make it possible to perform uncertainty quantification and sensitivity analyses in the nuclear structure calculations. In this talk, I will report the progress of the ab-initio coupled-cluster method in describing spherical and deformed atomic nuclei. I will also introduce the quantified predictions of the neutron skin thickness of 208Pb and the drip line of oxygen isotopes. |

15.12.2022 15:00 via Zoom |
Dr. Agnieszka Sorensen (INT Seattle)The speed of sound of dense nuclear matter from heavy-ion collisions The equation of state (EOS) of dense nuclear matter has been the center of numerous research efforts over the years. While numerous studies indicate that the EOS is relatively soft around the saturation density of nuclear matter, recent analyses of neutron star data strongly suggest that in the cores of neutron stars, where densities may reach several times that of normal nuclear matter, the EOS becomes very stiff – so stiff, in fact, that the speed of sound squared may substantially exceed the conformal limit of 1/3. This striking behavior inspires the research I will present in this talk. I will discuss a novel way of using higher moments of the baryon number distribution, measured in experiments, to infer the speed of sound in dense nuclear matter created in low-energy heavy-ion collisions. I will then present the framework I developed to enable comprehensive hadronic transport studies of the influence of the dense nuclear matter EOS on experimental observables, and I will discuss implications for the speed of sound of dense nuclear matter based on a recent analysis using this framework. |

24.11.2022 14:00 S2|11 10 |
Prof. Dr. Owe Philipsen (Goethe Universität Frankfurt)Chiral spin symmetry and the QCD phase diagramRecently, an emerging chiral spin symmetry was discovered in the multiplets of lattice QCD hadron correlators for a temperature window above the chiral crossover. This symmetry is larger than the expected chiral symmetry. It can only be approximately and dynamically realised when colour-electric quark-gluon interactions dominate the quantum effective action. This suggests the chiral spin symmetric regime to be of a hadron-like rather than partonic nature. After a brief review of the symmetry, I show independent evidence from meson screening masses and the pion spectral function, which support this picture. Finally, I discuss how this chiral spin symmetric band may continue across the QCD phase diagram, where it may smoothly connect to quarkyonic matter at low temperatures and high densities. |

17.11.2022 14:00 S2|08 171 (Uhrturmhörsaal) |
Dr. Marcel Schmidt (d-fine)How to save the financial system: My journey from Physics to Risk Management @ d-fineFor over 3 years I have worked at d-fine, a leading consultancy for analytically demanding topics from branches like finance, energy industry or manufacturing. Early in my career, I have specialized in market risk management. In our projects, we help banks to secure against price fluctuations, using state-of-the-art methods from mathematics, machine learning, and modern software development. In this talk, I would like to provide an impression on my career path and show how we as physicists contribute to a more secure financial system. |

10.11.2022 14:00 S2|11 10 |
Prof. Dr. Frithjof Karsch (Universität Bielefeld)QCD Phase Diagram and the Equation of State of Strong-Interaction MatterLattice QCD calculations at non-zero temperature and with non-vanishinq chemical potentials provide a powerful framework for the analysis of the phase structure of strongly interacting matter. Such calculations allow the determination of the crossover transition region at QCD with physical quark masses as well as the determination of the true chiral phase transition in the limit of vanishing light quark masses. We present results on the determination of the pseudo-critical and chiral phase transition temperatures as well as a new, high statistics determination of the QCD equation of state. We point out their importance for constraining the location of a possible critical end point in the QCD phase diagram. We furthermore present a new, high statistics determination of the QCD equation of state. |

27.10.2022 14:00 S2|11 10 |
Dr. Renwick James Hudspith (GSI)A complete lattice QCD determination of the hadronic light-bylight scattering contribution to the muon g-2 The g-2 of the muon provides a high-precision test of the Standard Model of particle physics, and a possible window into beyond the Standard Model physics. Currently, there is some tension between the theoretical prediction of this quantity and experiment. As experimental precision continues to improve it is paramount for theoretical computations to do so also, in hope of resolving this tension. One of the most poorly-known contributions to the theory calculation of the muon g-2 comes from hadronic light-bylight scattering. I will present an overview of our measurement of this contribution using lattice QCD techniques, where we have obtained the most precise determination to date. |