Ort / Place
Physik Campus Riedberg, Max-von-Laue-Str. 1, 60438 Frankfurt
Großer Hörsaal, Raum 0.111

Zeit / Time
Mittwochs / Wednesday , 16.00 Uhr c.t.

Prof. Dr. Michael Kramer
Max-Planck-Institut für Radioastronomie, Bonn, Germany
Astrophysics - University of Manchester, UK
University of Bonn, Germany

New Results in Tests of Gravity with Radio Pulsars


Prof. Dr. Luca Amendola
Institut für Theoretische Physik , Heidelberg University

Testing gravity with gravitational waves and cosmology


Prof. Dr. Gianluca Imbriani
Physics Department, University of Naples "Federico II", Napoli, Italy

Direct measurements of cross sections of Astrophysical interest

Prof. Dr. Wolfram Weise
TUM Emeritus of Excellence, Technische Universität München

Phases of Strongly Interacting Matter- from Quarks to Nuclei and Neutron Stars

The strong interaction of quarks and gluons is at the origin of almost all of the mass of the visible universe. The emergence of multifaceted phases and structures, from quarks to hadrons, atomic nuclei and neutron stars, is one of the persistently challenging issues of modern science.

This colloquium reviews our current understanding of the phases of Quantum Chromodynamics (QCD). Empirical information from nuclear collisions at the highest available energies will be briefly surveyed together with results from Lattice QCD thermodynamics. It is pointed out that important constraints on the phase diagram arise from nuclear physics and the treatment of the nuclear many-body problem using effective field theory approaches based on the symmetry breaking pattern of low-energy QCD. The presentation includes a discussion of stringent constraints on the equation-of-state of dense baryonic matter implied by the existence of massive (two-solar-mass) neutron stars. This topic is presently in a special focus through the recent observation of gravitational waves from merging neutron stars.

Prof. Dr. Laura Fabbietti
Technische Universität München

A new generation of hyperon-nucleon and hyperon-hyperon scattering experiments with ALICE

The study of the effective strong interaction among hadron pairs was pursued in the past via scattering experiments. 

For hyperon-nucleon pairs such as L-p, S-p, X-p the nature of the instable hyperon beams makes such measurements very difficult and consequently only scarce experimental data are available. Hyperon-hyperon interactions can not be accessed at all with this technique.

This kind of interactions is particularly interesting because of its connection to the physics of neutron stars. Indeed, these strong interactions drive the equation of state (EoS) of dense neutron-rich matter with strange quark content and such EoS can be tested against the measurements of neutron star masses, radii and newly detected gravitational wave signals. Since one of the hypotheses about the unknown content of neutron stars is that neutrons and hyperons are contained in the core, a detailed knowledge of the interaction becomes mandatory to investigate this hypothesis in a quantitative way.

In this talk we show how p+p and p+Pb collisions measured by ALICE at the LHC can be exploited to study these hyperon-nucleon and hyperon-hyperon interactions with unprecedented precision. Among others, we have observed for the first time the attractive pX- strong interactions.  Implications for neutron stars will be discussed.

Our correlation analysis opens a new era for hadron physics with strangeness substituting scattering experiments. 

This will provide us with precise constraints for the EoS of neutron-rich matter with hyperon content.


Rückblick Physikalisches Kolloquium:
SS 2010, WS 2010/11, SS 2011, WS 2011/12, SS 2012, WS 2012/13, SS 2013, WS 2013/14, SS 2014, WS2014/15, SS2015, WS2015/16, SS2016, WS2016/17, SS 2017, WS 2017/18, SS 2018