muon; muonic atom; atomic parity violation; nuclear charge radius; HPGe detector; gamma spectroscopy
Antognini Aldo, Rapisarda Elisa (2017), A stretto raggio: dalla spectroscopia muonica al raggio del protone, in Asimmetrie
, 23, 38-41.
Antognini Aldo, Berger Niklas, Cocolios Thomas Elias, Dressler Rugard, Eggenberger Andreas, Eichler Robert, Indelicato Paul, Jungmann Klaus, Kirch Klaus, Knecht Andreas, Papa Angela, Pohl Randolf, Pospelov Maxim, Rapisarda Elisa, Ritjoho Narongrid, Skawran Alexander, Wauters Frederik, Willmann Lorenz, Nuclear Structure with radioactive muonic atoms, in Fission 2017 – Sixth International Workshop on Nuclear Fission and Fission Product Spectroscopy
, ChamrousseEDP Sciences Journal, France.
Muonic atoms as laboratories for fundamental physics provide crucial input to quantum electrodynamics, the weak interaction and the strong interaction. Many studies of muonic atoms have relied on the detection of x-ray from the muonic cascades. For Lyman x-rays the energies range from few keV for the lightest atoms to several MeV for larger nuclear charge Z. Most stable and a few unstable isotopes have been investigated with muonic atom spectroscopy techniques. In particular, muonic atoms have been used to extract the most accurate nuclear charge radii. However, experiments with muonic atoms have been limited by low muon rates, poor beam quality and large muon stop volumes, but also by available detector technology for this environment. While beam intensities and quality have been improved in recent years, still no higher multiplicity spectroscopy of muonic cascades has been performed. Muonic x-rays have never been studied with highly efficient multi-Ge-detector arrays covering large solid angles. This research project will focus on the measurements of the muonic cascades of (i) Ra and of (ii) medium-mass muonic atoms using a large coverage Ge array placed at one of the several muon beam lines at the high power proton accelerator facility HIPA at the Paul Scherrer Institut.Both measurements deal with atomic parity violation (APV) that is a manifestation of the neutral weak interaction between lepton (electron, muon) and the nucleus and its constituents. The data on the muonic cascades will reveal unique information: (i) high precision nuclear-charge radius of Ra and (ii) discrimination of the 2S-->1S transition of high relevance for future parity violation studies in atomic Ra and in muonic atoms.