Zeit, Ort:

09:30 Uhr, Central Seminar Room (library)

Redner:

Tobias Heldt, Excited atoms & molecules in strong fields

Titel:

Strong-field dynamics near an ionization threshold

Zeit, Ort:

16:30 Uhr, Seminar room Lindner 339, Gentner lab, 2nd floor

Redner:

Dr. Peter Millington (Nottingham U.)

Titel:

Non-Hermitian QFTs

Zeit, Ort:

11:15 Uhr, Seminarraum 242, Bothe-Labor

Redner:

Dr. André Gontijo Campos, MPIK

Titel:

A novel method to construct analytical solutions of the Dirac Equation

Zeit, Ort:

14:00 Uhr, Central seminar room, library building

Redner:

Dr. Henrike Fleischhack, Michigan Tech University, USA

Titel:

News from the very-high-energy gamma-ray sky seen by HAWC

The HAWC (High-Altitude Water Cherenkov) Observatory is a wide-field very-high-energy (E>100 GeV) gamma-ray observatory located on Sierra Negra, Mexico. It has been taking data almost continuously for several years, and has detected gamma-ray emission from more than 50 sources, most of which are located within our own Galaxy. Recent improvements in the energy reconstruction have enabled the HAWC collaboration to present a large-scale gamma-ray survey above 100 TeV. In this presentation, I will present recent results from the HAWC experiment, focusing in particular on Galactic astrophysics (Supernova Remnants, extended emission around pulsars, star-forming regions), multi-messenger follow-up searches, and searches for new physics.

Zeit, Ort:

11:15 Uhr, Grosser Hoersaal/Big Lecture Hall (library)

Redner:

Prof. Timothy Chupp, Applied Physics and Biomedical Engineering, University of Michigan

Titel:

Challenging the Standard Model with Magnetic and Electric Dipole Moment Measurements

The current Standard Model of elementary particle interactions is a great success, yet leaves much unaccounted for: the dominance of matter vs antimatter generated in the early universe, neutrino masses and of course dark matter and dark energy. Thus it is clear that a New Standard Model must emerge and that it must be based on experiment. Two complimentary approaches for gaining ground in the laboratory are to look 1) where the Standard Model background is small and 2) to look where the Standard Model prediction is precise. Electric dipole moments are a signal of simultaneous parity (P) and time-reversal (T) symmetry violation implying CP violation (C is charge-conjugation) which is required to have contributions not included in the Standard Model (SM) - that is the SM background is small. We are searching for EDMs of the neutron and in heavy atoms in separate experiments. We are also measuring the magnetic moment anomaly of the muon, which is precisely predicted in the Standard Model and can be measured with similar precision. The current 3.6-sigma tension of experiment and theory for g-2 is considered a hint of new physics and has motivated the new Muon g-2 Experiment at Fermilab. I will describe our progress on these efforts and how we can learn about contributions to the New Standard Model from the results.

Zeit, Ort:

10:00 Uhr, Otto-Hahn-Hörsaal

Zeit, Ort:

10:40 Uhr, Otto-Hahn-Hörsaal

Zeit, Ort:

11:00 Uhr, Zentraler Seminarraum/Central Seminar Room (library)

Redner:

Prof. Dr. Ulrich Teubner, Hochschule Emden-Leer, AG Intensive Laserpulse

Titel:

Physics with ultrashort and intense light pulses

Zeit, Ort:

11:15 Uhr, Central Seminar Room (library)

Redner:

Dr. Samuel Hammer, CRL, Institut für Umweltphysik, Universität Heidelberg

Titel:

How to identify CO2 from fossil fuel combustion in the atmosphere? Another application of radiocarbon.

The natural carbon cycle has been altered by mankind for many centuries, mainly via burning fossil fuels and land use change. About half of the anthropogenic emissions have been taken up by the natural carbon cycle and do thus not contribute to the additional greenhouse gas effect. A key question for future climate is how the carbon cycle will respond to global warming. Studying the natural carbon cycle benefits strongly from the ability to separate atmospheric CO2 originating from the burning of fossil fuels from other CO2 sources. Experimentally this can most directly be achieved by determining the 14C content in atmospheric CO2.The mission of the European Research infrastructure ICOS (Integrated Carbon Observation System) is to conduct long-term high-quality observations in the three major carbon-cycle reservoirs: ocean, terrestrial biosphere and atmosphere. The atmospheric measurement network currently consists of 33 stations from which 16 do monitor 14CO2 in the atmosphere. Radiocarbon observations are conducted by a Central Radiocarbon Laboratory (CRL) to allow for the highest degree of compatibility between the 14C data sets. A second focus of the CRL is to develop new approaches to determine atmospheric ffCO2 (fossil fuel CO2) concentrations. Continuous ffCO2 estimates are extremely valuable when aiming for quantifying fossil fuel emissions from countries, regions or even cities. Here, atmospheric ffCO2 estimates provide a comprehensive and independent check to monitor promised emission reduction efforts. For this, we exploit the potential of different ffCO2 surrogate tracers like CO, NOx or O2/N2. The talk will introduce the above mentioned different aspects of our work and will illustrate them with our latest findings.