课程信息

Course Contents
What is the radius of a proton? Are the magic numbers universal or are they valid only close to the ß-stability
region of the nuclear chart? Do we understand Quantum Electrodynamics (QED) in extremely strong electric and
magnetic fields? What are the properties of antihydrogen? Why is there more matter in the universe than antimatter?
These are just a few fundamental questions for which researchers seek answers using laser spectroscopy techniques.
Searching for „Physics beyond the Standard Model“ requires extremely high precision and complements accelerator-based
experiments at ever higher energies. Like a criminalist searches for traces at the site of crime, laser spectroscopic
measurements try to uncover the activity of unknown particles that are not part of the Standard Model. But laser
spectroscopic tools are also indispensable to determine the size and structure of short-lived nuclei and for the
preparation of atoms and ions for other experiments.

The aim of this course is to provide an overview on laser spectroscopic approaches to perform high-precision laser spectroscopy measurements either on systems that might be termed „exotic“ since they do not exist under normal conditions or measurements on more „normal“ systems with the goal to study „exotic“ particles or forces that might cause extraordinary properties of the atom or ion under investigation.

The content is divided into four chapters which partially have some overlap. We will start with spectroscopy on hydrogen-like systems, including hydrogen itself (not very exotic but fundamental), Positronium and similar leptonsystems as well as anti-hydrogen. In chapter 2 we will discuss spectroscopy on highly charged ions, where some spectacular progress was made recently. Here, hydrogen-like ions will be again an interesting topic.
The third chapter will be about laser spectroscopy of short-lived isotopes, mostly in order to study nuclear properties, but we will
also learn how radioactive ions can be prepared for other experiments using lasers. Finally we will discuss laser spectroscopy for tests of the standard model of particle physics or fundamental symmetries like special relativity.

In all cases, we will have a look on the theoretical background of the experiments, the technology being used to prepare the exotic systems and the laser spectroscopic techniques themselves. Experiments are carried out at and in accelerators, storage rings, ion and atom traps. Trapping and cooling techniques are regularly employed to achieve high accuracy.

Content:

1 Laser Spectroscopy of Hydrogenlike Systems
1.1 Introduction
1.2 Laser Spectroscopy of Hydrogen: Proton Radius and Rydberg Constant
1.3 Laser Spectroscopy of Muonic Hydrogen
1.4 Laser Spectroscopy of Positronium
1.5 Laser Spectroscopy of Muonium
1.6 Laser Spectroscopy of Antihydrogen and the CPT Theorem
1.7 Antiprotonic Helium and the electron mass

2 Laser Spectroscopy of Highly Charged Ions (HCI)
2.1 Motivation .
2.2 Some Aspects of HCI-Physics
2.3 Electron Impact Ionization and Charge Exchange
2.4 Transition Wavelength and Photon Energies
2.5 Highly Charged Ions at Storage Rings
2.6 Electron Beam Ion Traps (EBIT)
2.7 Laser Spectroscopy in a Penning Trap
2.8 Laser Spectroscopy of HCI in an RF Paul trap

3 Laser Spectroscopy of Short-Lived Isotopes
3.1 Introduction
3.2 Production of Short-Lived isotopes
3.3 Nuclear Signatures in the Optical Spectrum
3.4 Resonance Ionization Spectroscopy (RIS)
3.5 Collinear Laser Spectroscopy (CLS)
3.6 Atom Trap Laser Spectroscopy on Helium Isotopes

4 Tests of Fundamental Symmetries
4.1 Atomic Parity Violation
4.2 Searches for a permanent eletric dipole moment
4.3 Test of time dilation in Special Relativity

 

Literature
There is no textbook containing all contents of the lecture. A script and the slides are provided with references to review articles.

Laser spectroscopic methods are detailled in the book "Laser Spectroscopy" by Demtröder (Springer)

Preconditions
Knowledge of the content of the bachelor modules on nuclear physics (Physics VI) and atomic physics (Physics IV) are expected.