Chiral model calculations, assuming a partial restoration of chiral symmetry in a nuclear medium, predict modifications of meson properties within nuclei. This motivated a still ongoing widespread experimental campaign starting in the 1990’s to measure the properties of mesons in photon-, pion-, and proton-induced reactions on nuclei and in relativistic and ultra-relativistic heavy-ion...
In muonic atoms, a single muon replaces all of the atomic electrons, resulting in a 2-body system whose hydrogen-like theory is very well understood. The large muon mass of 200 times the electron mass results in a 200^3 = 10 million fold improved sensitivity of muonic-atom energy levels to nuclear structure. Using laser spectroscopy, we have investigated the charge radii of Z=1 and 2 (H to...
Recent results have brought conclusive and/or intriguing answers to important questions in hot QCD. I will discuss some of those answers and the new questions that they pose, and will point to some of the upcoming new experimental facilities that should provide the next round of discoveries.
The difference in proton-proton and neutron-neutron scattering lengths contributes to understanding the charge-symmetry breaking of nuclear forces, yet the Coulomb-free proton-proton scattering length (app) cannot be measured directly and relies heavily on numerous and distinct theoretical techniques to remove the Coulomb contribution. We determined the Coulomb-free p-p scattering length from...
Neutron stars are the densest stellar objects with densities exceeding those in atomic nuclei. Consequently, the collision of two neutron stars creates very extreme conditions and leads to a variety of different highly energetic and potentially observable phenomena: electromagnetic radiation from radio to gamma wavelengths, neutrinos and gravitational waves. Since the first unambiguous...
