Semesterübersicht Wintersemester 2022/2023
Sommersemester 2022  Wintersemester 2022/2023  Sommersemester 2023
Seminar about Experimental Particle and Astroparticle Physics (ETAP)
Institut für Physik 12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum 
Olivera Vujinovic, Institut für Physik  
Searches for Axions at the LHC  
at Zoom  

RIND seminar on Mathematical Physics and String Theory
U. Mainz, LMU Munich, U. Heidelberg, U. Vienna 16 Uhr c.t., Munich 
Albrecht Klemm, Bonn U.  
Recently it has been realized that the parameter dependence of
Feynman integrals in dimensional regularisation can be calculated
explicitly using period and chain integrals of suitably chosen
CalabiYau motives, where the transcendentality weight of
the motive is proportional to the dimension of the Calabi Yau
geometry and the loop order of the Feynman graphs. We exemplify
this for the Banana graphs, the Ice Cone graphs and the Train Track graphs
in two dimensions. In the latter case there is a calculational very useful
relation between the differential realisation of the
Yangian symmetries and the PicardFuchs system of compact
CalabiYau spaces M as well as between the physical correlations
functions and the quantum volume of the manifolds W that are the
mirrors to M.  
at Zoom  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Dr hab. Wojciech Gawlik, JU Krakow, PL  
I will begin with a historical introduction starting from Michael Faraday’s discovery of the magnetooptical phenomena and the basic physics behind it.
Next, I will present the revolution caused by the advent of lasers in magnetooptics studies and the developments which made the nonlinear magnetooptics
one of the most precise measurement techniques. While focusing on hot atomicvapor samples, I will also present some magnetooptic studies with cold,
trapped atoms and colour centers in diamonds and their applications to magnetometry.  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Dr. ChienYeah Seng, Univ. Bonn  
The precision measurement of the toprow CabibboKobayashiMaskawa (CKM) matrix element $V_{ud}$ from beta decays of pion, neutron and nuclei plays an important role in lowenergy precision tests of Standard Model (SM) predictions. The recent observation of an apparent deficit of the toprow CKM unitarity has attracted wide attentions and provided hints for physics beyond the Standard Model (BSM). Higher precision for the $V_{ud}$ extraction is needed to confirm (or reject) such an observation; in this talk the referent will discuss some ongoing efforts from the theory and experimental side to achieve this goal. Slides here...  

SPICESpin+X Seminar
TUK and JGU 15:00 Uhr s.t. 
James McIver, MPSD and Columbia University  
Ultrafast optoelectronic probes of quantum materials  
at Zoom and SPICE YouTube Channel  

Seminar über Quanten, Atom und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05127 
Prof. Dr. hab. Wojciech Gawlik, Jagiellonian University, Poland  
By simultaneous application of a laser and two microwave fields upon a spin system (e.g. NV centers in diamond) one can observe magnetic resonance structures with twocomponent, composite shapes of nested Lorentzians with different widths. One component is regularly powerbroadened, whereas the linewidth of the other one undergoes fieldinduced stabilization and becomes powerindependent. The observed stabilization appears to be a general phenomenon that occurs in open systems. It is caused by the competition between coherent driving and nonconservation of populations and can be interpreted in terms of specific bright and dark combinations of state populations.
Bio: Studied physics at the Jagiellonian University in Kraków (MSc in 1970), 197274 worked in the Physikalisches Inst. der Uni Heidelberg (with G. zu Putlitz), PhD in 1975 (Uni Kraków). Longer research stays: Reading (GB) with G.W. Series, Munich with H. Walther, Paris with S. Haroche, Boulder with A. Gallagher, Berkeley with D. Budker. Head of the Atomic Optics Dept. (199094) and Photonic Dept. (20032017) in Jagiellonian Univ. (Kraków), since 2018 Professor Emeritus at the Institute of Physics Jagiellonian University.  

Seminar about Experimental Particle and Astroparticle Physics (ETAP)
Institut für Physik 12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum 
Liam O'Sullivan, Institut für Physik  
CrossSection Measurements with the T2K Near Detector ND280  
at Zoom  

RIND seminar on Mathematical Physics and String Theory
U. Mainz, LMU Munich, U. Heidelberg, U. Vienna 16 Uhr c.t. 
Lorenz Eberhardt, IAS  
I will revisit string oneloop amplitudes in this talk. After reviewing the basics, I will explain how Witten’s iepsilon prescription gives a manifestly convergent representation of the amplitude. I will then consider the imaginary part of the amplitude and show directly that it satisfies the standard field theory cutting rules. This leads to an exact representation of the imaginary part of the amplitude. I will also discuss physical properties of the imaginary part such as the singularity structure of the amplitude, its Regge and high energy fixedangle behaviour and lowspin dominance. Finally, I will tease how Rademacher’s contour can be used to evaluate the full oneloop open string amplitude exactly in terms of a convergent infinite sum.  
at Zoom  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Dr. Carsten Brandau, GSI Darmstadt  
Towards storage ring studies of highly charged 229Th  

SPICESpin+X Seminar
TUK and JGU 15:00 Uhr s.t. 
Eric Fullerton, UC San Diego  
Stripe domain phases in chiral magnetic systems with perpendicular anisotropy  
at Zoom and SPICE YouTube Channel  

Seminar über Quanten, Atom und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05127 
Dr. Benjamin Stickler, Imperial College London, Dept. of Physics  
Controlling the quantum dynamics of massive and complex objects, such as large molecules and nanoparticles, requires a detailed understanding of the interaction between their many interacting degrees of freedom and control fields. In this talk, I will discuss how light scattering induces nonreciprocal interactions between colevitated objects [1], how the rotational quantum interference of nanoparticles with embedded nitrogenvacancy centres gives rise to novel quantum phenomena [2,3], and how diffraction of chiral molecules can prepare superpositions of molecular configurations [4]. These examples illustrate the potential of macromechanical quantum systems for novel force and torque sensing schemes and for highmass tests of quantum physics.
[1] Rieser, Ciampini, Rudolph, Kiesel, Hornberger, Stickler, Aspelmeyer, and Delić, Tunable lightinduced dipoledipole interaction between optically levitated nanoparticles, Science 377, 987 (2022).
[2] Stickler, Hornberger, and Kim, Quantum rotations of nanoparticles, Nat. Rev. Phys. 3, 589 (2021).
[3] Rusconi, Perdriat, Hétet, RomeroIsart, and Stickler, Phys. Rev. Lett. 129, 093605 (2022).
[4] Stickler, Diekmann, Berger, Wang, Phys. Rev. X 11, 031056 (2021).
Short Bio:
I studied Chemistry and Physics at TU Graz, and received my PhD in Physics form the University of Graz in 2013. I held postdoc positions at the University of DuisburgEssen and at Imperial College London (as a Marie Sklodowska Curie Fellow). I obtained my Habilitation at the University of Duisburg Essen in 2022, where I now work on the theory of macroscopic quantum physics and levitated nanomechanics.. In 2022, I was elected into the NRW Academy of Sciences and Arts as a Young Fellow and I was recently admitted to the prestigious Heisenberg Programme by the DFG.  

Seminar about Experimental Particle and Astroparticle Physics (ETAP)
Institut für Physik 12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum 
Ioana Caracas, Institut für Physik  
Study of High Energy Steeply Upgoing Air Showers with the Fluorescence Detector of the Pierre Auger Observatory  Constraining BSM Scenarios Producing Upgoing τ Leptons  
at Zoom  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Dr. Horst SchmidtBöcking, University of Frankfurt  
In der Nacht vom 7. auf den 8. Februar 1922 gelang es Walther Gerlach und Otto Stern im sogenannten SternGerlachExperiment SGE, zum ersten Male das magnetische Moment eines Atoms, des Silberatoms, zu messen und den Beweis zu erbringen, dass Arnold Sommerfelds und Pieter Debyes Postulat der Richtungsquantelung von atomaren magnetischen Momenten in einem äußeren Magnetfeld der Wahrheit entsprach.
Das Messprinzip des Experimentes als hochauflösendes Impulsspektrometer für einzelne Atome im Vakuum und der historische Weg der Durchführung dieses Experimentes werden dargestellt. Das Ergebnis des SGE zeigte damit auch erstmals, dass auch die inneratomaren Drehimpulse gequantelt sind. Die Bedeutung des SGE für die Entwicklung der Quantenphysik besprochen.  

TheoriePalaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) 
Cem Eröncel, DESY  
Axionlikeparticle (ALP) is a wellmotivated candidate for dark matter, and it has been subject to extensive theoretical and experimental research in recent years. The most popular ALP production mechanism studied in the literature is the misalignment mechanism, where the ALP field initially has negligible kinetic energy and starts oscillating when its mass becomes comparable to the Hubble scale. Recently, a new mechanism called Kinetic Misalignment has been proposed where the ALP field receives large kinetic energy at early times due to the explicit breaking of the PecceiQuinn symmetry. This causes a delay in the onset of oscillations so that the ALP dark matter parameter space can be expanded to lower values of the axion decay constant. At the same time, the ALP fluctuations grow exponentially via parametric resonance in this setup, and most of the energy in the homogeneous mode is converted to ALP particles. This process is known as fragmentation. In this talk, I will discuss the observational consequences of fragmentation for the axion miniclusters and show that a sizable region of the ALP parameter space can be tested by future experiments that probe the smallscale structure.  
at Zoom  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Prof. Dr. Alessandro Roggero, Univ.Trento, Italy  
In extreme astrophysical environments like supernova explosions, the large neutrino density can
lead to collective flavor oscillations driven by neutrinoneutrino interactions. These phenomena
are important to describe flavor transport and have potentially important consequences for both
the explosion mechanism and nucleosynthesis in the ejected material. Even simple models of
neutrinoneutrino interactions require the solution of a challenging manybody problem whose
exact solution requires exponential resources in general. In this talk the referent will describe the physics
of collective flavor oscillations and present the recent efforts to simulate the realtime flavor
dynamics of twoflavor neutrinos using current generation quantum computers based on both
superconducting qubits as well as trapped ions.  

Seminar über Quanten, Atom und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05127 
Dr. Anna Ermakova, MPI Mainz  
Color centers in diamonds offer wonderful sensing possibilities in the case of the detection of magnetic or electric fields or temperature. Color centers in nanodiamonds can be incorporated into the biological systems to investigate them. One of the biggest advantages of quantum sensors based on nanodiamonds is that they operate at room temperature or higher. Therefore, they can be used to study living systems. We investigate how nanodiamonds can be brought into the living system in the most efficient way and what information we can get from them.
Bio: Studied physics in Belarusian State University (MSc in 2011), PhD in physics (magna cum laude) with Fedor Jelezko at Ulm University, Institute for Quantum Optics (20112016). From 2017 to 2021 she held positions as a postdoc at Ulm University, researcher at Silicon Austria Lab GmbH, and a senior scientist at MPIP (Mainz). Since 2022 – Anna is Independent Group Leader at MaxPlanckInstitute for Polymer Research, Mainz, Germany supported by CarlZeiss Foundation, her group works on investigating potential of Nanodiamonds for intracellular magnetometry and thermometry, novel alloptical sensing methods, and cell metabolism processes.  

GRK 2516 Soft Matter Seminar
Uni Mainz 14:30 Uhr s.t., Minkowski Room, 05119, Staudingerweg 7 
Gokul Govind, JGU, Physics  
Sequence controlled polymerization is an inevitable process in natural systems. The amino acid sequence arrangement is the vital part in determining the structure function of proteins. This process of selection and formation of sequence interests scientists to build polymers that are made of selfassembled monomers that interact through Van der Waals interactions such as hydrogen bonds and hydrophobic interactions. In this talk I will be discussing the copolymerization of two monomers that are having hydrophobic and hydrophilic domains whose interplay induces a supramolecular polymerization in water. We discuss the concentration factors that can contribute to the formation of homopolymers and copolymers with different sequences.
References :
Macromol. Rapid Commun. 2021, 2100473
Macromolecules 2019, 52, 7661−7667
J. Am. Chem. Soc. 2020, 142, 16, 7606–7617  
at Zoom  

GRK 2516 Soft Matter Seminar
Uni Mainz 15:00 Uhr s.t., Minkowski Room, 05119, Staudingerweg 7 
Bhuwan Poudel, MPIPolymer Research  
It is crucial to understand how stimuliresponsive polymer surfaces, such as polymer brushes, accommodate nanoparticles and how the presence of nanoparticles alters the structural and dynamical properties of the brushes in order to use the brush/NPs hybrid in optimal applications.
We plan on answering this question by carrying out detailed molecular dynamics simulations. As a first step toward the project's goal, we investigated the properties of brushes and studied how a nanoparticle interacts with them.  
at Zoom  

TheoriePalaver
Institut für Physik 15:00 Uhr s.t., HIM building, room 02.111 
Pere Masjuan, Universitat Autonoma de Barcelona  
The role of Pade approximants as fitting functions  
Note the special time and room. 
Seminar about Experimental Particle and Astroparticle Physics (ETAP)
Institut für Physik 12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum 
Martin Rongen, Institut für Physik  
Insitu estimation of ice crystal properties at the South Pole using LED calibration data from the IceCube Neutrino Observatory  
at Zoom  

RIND seminar on Mathematical Physics and String Theory
U. Mainz, LMU Munich, U. Heidelberg, U. Vienna 16 Uhr c.t. 
Raghu Mahajan, Stanford U.  
We use insights from string field theory to analyze and cure the divergences in the cylinder diagram in minimal string theory, with both boundaries lying on a ZZ brane. Minimal string theory refers to the theory of twodimensional gravity coupled to a minimal model CFT that serves as the matter sector; it includes JT gravity as a limiting case. ZZ branes are akin to Dinstantons, and give rise to features that reflect the underlying discreteness of the dual theory. The exponential of the cylinder diagram represents the oneloop determinant around the instanton saddle. The finite result for this oneloop constant computed using the string field theory procedure agrees precisely with independent calculations in the dual doublescaled matrix integrals performed by several authors many years ago.  
at Zoom  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Dr. Peter Spichtinger, JGU Institute for Atmospheric Physics  
Ice clouds constitute an important component in the Earthatmosphere system. Like all clouds, they influence the hydrological cycle and the energy budget of the system. Thereby, the partial reflection of incident radiation results into a cooling effect (albedo effect), and the absorption and reemission of thermal radiation results into a warming effect (greenhouse effect). However, for ice clouds in the tropopause region the net effect (warming or cooling) is unclear, because both opposite effects are of the same order of magnitude. Thus, the net effect depends on further properties of the multiscale system of ice clouds, such as the size and shape of the crystals, as well as the formation of structures within clouds resulting into heterogeneous media. In particular, the formation of structures in (ice) clouds is relatively poorly known so far and requires further investigation.
In this talk we investigate processes and phenomena on different scales of ice clouds. We start with single crystals and their properties, as well as methods to measure these particles. To represent the ensemble ice cloud, models have to be developed and further investigated. The formulation of reduced order models leads us to ice clouds as nonlinear oscillators. The interaction on different scales and of different processes finally leads to the formation of characteristic structures. These investigations are current research and are carried out in interdisciplinary collaboration.  

TheoriePalaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) 
Mathias Becker, JGU Mainz  
A nonminimal dark sector could explain why WIMP dark matter has evaded
detection so far. Based on the extensively studied example of a simplified
tchannel dark matter model involving a colored mediator, we demonstrate that
the Sommerfeld effect and bound state formation must be considered for an
accurate prediction of the relic density and thus also when inferring the
experimental constraints on the model. We find that parameter space thought to
be excluded by LHC searches and direct detection experiments still remains
viable. Moreover, we point out that the search for bound state resonances at the
LHC offers a unique opportunity to constrain a wide range of dark matter
couplings inaccessible to prompt and longlived particle searches.  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Dr. Graziano Venanzoni, Frascati, Italy  
The latest measurement of the muon g2 announced at Fermilab exhibits a 4.2$\sigma$ discrepancy from the currently accepted Standard Model prediction. The main source of uncertainty on the theoretical value is represented by the leading order hadronic contribution $a_{\mu}^{HLO}$, which is traditionally determined through a datadriven dispersive approach. A recent calculation of $a_{\mu}^{HLO}$ based on lattice QCD is in tension with the dispersive evaluation, and reduces the discrepancy between theory and experiment to 1.5$\sigma$. An independent evaluation of $a_{\mu}^{HLO}$ is therefore required to solve this tension and consolidate the theoretical prediction.
The MUonE experiment proposes a novel approach to determine $a_{\mu}^{HLO}$ by measuring the running of the electromagnetic coupling constant in the spacelike region, via $\mue$ elastic scattering. The measurement will be performed by scattering a 160 GeV muon beam, currently available at CERN's North Area, on the atomic electrons of a lowZ target. A Test Run on a reduced detector is planned to validate this proposal. The status of the experiment in view of the Test Run and the future plans will be presented. Slides here...  

SPICESpin+X Seminar
TUK and JGU 15:00 Uhr s.t. 
Yoav William Windsor, FH Institute of the MPS and TU Berlin  
Towards a "complete" picture of ultrafast dynamics in the 2D ferromagnet FGT  
at Zoom and SPICE YouTube Channel  

Seminar about Experimental Particle and Astroparticle Physics (ETAP)
Institut für Physik 12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum 
Patrycja Potepa, Institut für Physik  
Ttbar production in Pb+Pb collisions  
at Zoom  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Dr. Erwin Frey, University of Munich  
Protein pattern formation is essential for the spatial organization of intracellular processes like cell division, and flagellum positioning. A prominent example of intracellular patterns is the oscillatory poletopole oscillations of Min proteins in E. coli whose function is to ensure precise cell division. Cell polarization, a prerequisite for processes such as stem cell differentiation and cell polarity in yeast, is also mediated by a diffusionreaction process. More generally, these functional modules of cells serve as model systems for selforganization, one of the core principles of life. Under which conditions spatiotemporal patterns emerge, and how these patterns are regulated by biochemical and geometrical factors are major aspects of current research. In this talk I will review recent theoretical and experimental advances in the field of intracellular pattern formation, focusing on general design principles and fundamental physical mechanisms.  

TheoriePalaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) 
Alfredo Guerrera, Padua U. and INFN  
AxionLikeParticles are among the most economical and well motivated extensions of the Standard Model. In this talk ALP
production from hadronic and leptonic meson decays are studied. The hadronization part of these decay amplitudes has been
obtained using BrodskyLepage method or LQCD, at needs. In particular, the general expressions for ALP emission in mesonic
s and tchannel treelevel processes are thoroughly discussed, for pseudoscalar and vector mesons. Accordingly, exact
results as well as some useful approximation for mesontomeson and meson leptonic decay amplitudes are presented.
I will the discuss the phenomenology of various decays and highlight the most robust in terms of experimental searches
and theoretical predictions. Finally, bounds on the (lowenergy effective Lagrangian) ALPfermion couplings are derived,
from present and future flavour experiments. If I have time left I'll also cover some of the new form factors calculations in B mesogenesis.  
at Zoom  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Francesca Carlin, Berlin (Please note: Event will take 2 hours)  
Evaluations and selections determine scientific careers possibly like no other factor. Knowing that they are also susceptible to bias and preconceptions, how can we ensure a fair recruitment process and assure to pick the best candidate? Together, we want to reflect how we hold discussions in selection committees (on all career levels!) and learn what practices prove helpful in guaranteeing more equitable opportunities for all applicants.
Please register through prisma@unimainz.de to receive preparatory material. Slides here...  

Seminar über Quanten, Atom und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05127 
Dr. Lars von der Wense, LMU München  
Optical atomic clocks are today’s most accurate timekeeping devices. They achieve stunning relative accuracies in the range of 1018, corresponding to an error of 1 second in 30 billion years. An even improved accuracy is expected to be achieved by a nuclear optical clock, since the nucleus is significantly less sensitive to external influences than the atomic shell.
Developing a nuclear optical clock requires laser spectroscopy of a nuclear transition, an objective which has so far not been achieved, but which has come into reach due to recent gain of knowledge.
In this talk I will give an overview over the recent progress that has been made toward the development of a nuclear optical clock. I will introduce several experiments that are currently in preparation aiming toward firsttime laser spectroscopy of a nuclear transition. Finally, I will introduce the investigations planned within the framework of the newly funded BMBF project “NuQuant”.  

GRK 2516 Soft Matter Seminar
Uni Mainz 14:30 Uhr s.t., Minkowski Room, 05119, Staudingerweg 7 
Seraphine Wegner, WWU Münster  
Bottomup synthetic biology aims to construct celllike systems starting from molecular building blocks. These synthetic cells give insight into the molecular details and principles that give rise to cell function. Many functions in cells arise directly from the spatial and temporal regulation of cellmatrix and cellcell interactions. In this talk, I will present strategies of how such spatiotemporal control over adhesions of synthetic and natural cells can be achieved with visible light and functions that arise from these. The photoswitchable adhesions allow us recapitulate cell migration, to selfassemble and selfsort cells into multicellular functional architectures with high precision, regulate their interactions with synthetic materials, program cell to cell communication and to study the underlying biology. Synthetic minimal cells, which reduce complexity and yet capture key features of natural cells, allow us to quantify and correlate cell behavior with molecular information. Further, complementary approaches pursued with synthetic minimal cells as well as bacterial and mammalian cells allow translating concepts between different systems and integration into hybrid structures. Overall, our work on one hand provides insight into underlying design principles of life and on the other hand engineer new synthetic cell biology.  
at Zoom  

RIND seminar on Mathematical Physics and String Theory
U. Mainz, LMU Munich, U. Heidelberg, U. Vienna 16 Uhr c.t. 
Enno Keßler, MPIM Bonn  
Jholomorphic curves or pseudoholomorphic curves are maps from Riemann
surfaces to symplectic manifolds satisfying the CauchyRiemann equations.
Jholomorphic curves are of great interest because they allow to construct
invariants of symplectic manifolds and those invariants are deeply related to
topological superstring theory. A crucial step towards Gromov–Witten
invariants is the compactification of the moduli space of Jholomorphic curves
via stable maps which was first proposed by Kontsevich and Manin.
In this talk, I want to report on a supergeometric generalization of J
holomorphic curves and stable maps where the domain is a super Riemann
surface. Super Riemann surfaces have first appeared as generalizations of
Riemann surfaces with anticommutative variables in superstring theory. Super
Jholomorphic curves couple the equations of classical Jholomorphic curves
with a Dirac equation for spinors and are critical points of the
superconformal action. The compactification of the moduli space of super J
holomorphic curves via super stable maps might, in the future, lead to a
supergeometric generalization of GromovWitten invariants.
Based on arXiv:2010.15634 [math.DG] and arXiv:1911.05607 [math.DG], joint with
Artan Sheshmani and ShingTung Yau.  
at Zoom  

aktuell
TheoriePalaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) 
Markus Fröb, U. Leipzig  
Perturbative Quantum Gravity (pQG), the effective quantum field theory of gravitational fluctuations around a given background, is currently the only experimentally accessible theory of quantum gravity. Its treelevel predictions, in the form of temperature fluctuations of the Cosmic Microwave Background, have been experimentally confirmed, and it is possible that loop corrections are accessible to future experiments. However, while the treelevel results are well understood also from a theoretical point of view, the diffeomorphism symmetry of gravity makes the construction of invariant observables very difficult beyond this. Only recently, this issue has been overcome, and a class of causal invariant observables has been constructed. I will discuss this construction and how it can be related to observations, and present some predictions of pQG for graviton loop corrections to the Newtonian gravitational potential and the Hubble rate, the local expansion rate of the universe. Lastly, I show that pQG also predicts that spacetime becomes noncommutative at the Planck scale, but in a different way from previous approaches. The talk is based (in particular) on the recent papers arXiv:1806.11124, 2108.11960, 2109.09753 and 2207.03345.  
at Zoom  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Dr. Katrin AmannWinkel, MPI für Polymerforschung Mainz  
Water is ubiquitous and the most important liquid for life on earth. Although the water molecule is seemingly simple, various macroscopic properties of water are most anomalous, such as the density maximum at 4°C or the divergence of the heat capacity upon cooling. Computersimulations suggest that the anomalous behaviour of ambient and supercooled water could be explained by a two state model of water. An important role in this ongoing debate plays the amorphous forms of water. Since the discovery of two distinct amorphous states of ice with different density (high and low density amorphous ice, HDA and LDA) it has been discussed whether and how this phenomenon of polyamorphism at high pressures is connected to the occurrence of two distinct liquid phases (HDL and LDL). Xray free electron laser allow us to investigate metastable states of supercooled water within nano to microseconds. In my talk I will give an overview on our recent Xray experiments on supercooled water and amorphous ices.  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Prof. Dr. Tetyana Galatyuk, GSI Darmstadt  
What happens when gold nuclei, accelerated to about 90% of the speed of light, strike gold nuclei at rest? For an extremely short time, t~10^23 seconds, states of matter at extreme temperatures (10^12 K) and densities (>280 Mt/cm^3) are produced. The microscopic properties of the stronginteraction matter under extreme conditions of temperature and density is a topic of great current interest. Despite 18 orders of magnitude difference in system size and time, the conditions present in heavyion collisions share great overlap with the conditions of the stronginteraction matter in neutronstar mergers. The possibility to form and explore in the laboratory stronginteraction matter under extreme conditions is truly fascinating.
The Compressed Baryonic Matter (CBM) experiment at FAIR has the potential to discover the most prominent landmarks of the QCD phase diagram expected to exist at high net baryon densities. The measurement of comprehensive set of diagnostic probes offers the possibility to find signatures of exotic phases, and to discover the conjectured first order deconfinement phase transition and its critical endpoint.
In this talk the referent will focus on relevant observables to study criticality, emissivity, vorticity and equationofstate of baryon rich matter. Particular emphasis is put on rare probes which are not accessible by other experiments in this energy range.  

SPICESpin+X Seminar
TUK and JGU 15:00 Uhr s.t., Zoom 
Alice Mizrahi, CNRSThales  
Multilayer spintronic neural networks with radiofrequency connections  
at Zoom and SPICE YouTube Channel  

Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDynSeminar)
JGU 10:00 Uhr s.t., TUK, Building 76, Room 276 (LASE) 
Prof. Victor L’vov, Dept. of Chemical and Biological Physics, Weizmann Institute of Science  
Hydrodynamic turbulence in superfluid Helium: basic ideas, experiments, and physical models  
at Zoom  

Seminar über die Physik der kondensierten Materie (SFB/TRR173 Spin+X und SFB/TR288 Kolloquium, TopDynSeminar)
JGU 16:15 Uhr s.t., 01122 Newton Raum 
Martin Beye, DESY  
Resonant inleastic Xray scattering (RIXS) especially in the soft Xray region has seen a tremendous increase in applicability and scientific insight over the recent years. This was largely enabled by progress in instrumentation and theoretical description. Now the time is ripe to apply RIXS to pressing problems and develop the technique further making full use of the capabilities of novel Xray sources. In my talk, I will address three main themes from my research:
1. Timeresolved RIXS at freeelectron lasers applied to relevant dynamic processes in chemistry (on surfaces, in liquids and in solid catalysts)
2. RIXS with micrometer spatial resolution to resolve domain dynamics in complex materials and on devices inoperando
3. Nonlinear spectroscopies in the soft Xray range to enhance information content and signal levels I will show and discuss experimental results from all research themes and point to future development directions.  

Seminar über Theorie der kondensierten Materie / TRR146 Seminar
K. Binder/ A. Nikoubashman / F. Schmid / G. Settanni / T. Speck / M. Sulpizi / P. Virnau 15:00 Uhr s.t., Remote 
Oliver Beckstein, Arizona State University  
TBA  

Seminar about Experimental Particle and Astroparticle Physics (ETAP)
Institut für Physik 12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum 
Rainer Wanke, Institut für Physik  
tba  
at Zoom  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Dr. Peter Hommelhoff, University of Erlangen  
Optical fields can now be controlled with similar degrees of freedom as microwave fields for many decades already: we can now control not just
the pulse envelope but also the optical carrier field. With few cycle laser pulses, this allows steering of electrons in unprecedented ways. I
will give an overview over recent experiments we performed mainly with the atomically thin material graphene. Here we can drive the intraband
motion of electrons but also interband transitions. For the intense ultrashort fields we employ, these processes become intricately coupled
 a hallmark of strongfield physics. In particular, we could observe subsequent coherent LandauZener transitions, leading to
LandauZenerStückelbergMajorana interferometry, representing fully coherent electron dynamics in a roomtemperature material. In the
second part of the talk, we will shine light on the graphenegold interface and how it will add to the currents we can excite. Because of
the different symmetries involved, we can disentangle virtual and real carrier excitations. With these insights, we have recently demonstrated
a first Boolean logic gate based on two laser pulses carrying the logic information in the carrier envelope phase, which might bring lightwave
or petahertz electronics closer to reality.  

TheoriePalaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) 
Johanna Erdmenger, Würzburg U.  
TBA  
at Zoom  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Prof. Dr. Tim Cohen, CERN, Switzerland  
The referent will describe some recent work on applying Effective Field Theory (EFT) methodology to three different physically interesting systems. First he will explain the philosophy and general methodology of EFT. He will then present three short vignettes. The first has to do with techniques for systematically computing the EFT parameters from a given more fundamental description. The second will show how EFT can be used to understand the behavior of quantum fields in an inflationary background, with applications to light scalar fields and the inflaton itself. And in the third, the referent will show how EFT ideas can be applied to systematically improve a numerical technique for quantum field theory known as Hamiltonian truncation.  

Seminar über Quanten, Atom und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05127 
Dr. Nikita Kavokine, MPI for Polymer Research, Mainz  
Liquids are usually described within classical physics, whereas solids require the tools of quantum mechanics. I will show how in nanoscale systems this distinction no longer holds. At these scales, liquid flows may in fact exhibit quantum effects as they interact with electrons in the solid walls. I will first discuss the quantum friction phenomenon, where charge fluctuations in the liquid interact with electronic excitations in the solid to produce a hydrodynamic friction force. Using manybody quantum theory, we predict that this effect is particularly important for water flowing on carbonbased materials, and we obtain experimental evidence of the underlying mechanism from pumpprobe terahertz spectroscopy. I will then show how the theory can be pushed one step further to describe hydrodynamic Coulomb drag – the generation of electric current by a liquid in the solid along which it flows. This phenomenon involves a subtle interplay of electrostatic and electronphonon interactions, and suggests strategies for designing materials with low hydrodynamic friction.
Bio: Nikita Kavokine obtained a Bachelor in Chemistry and a Master in Theoretical Physics from Ecole Normale Supérieure (ENS) in Paris. He continued at ENS for his PhD, in the group of Prof. Lydéric Bocquet, working on both theory and experiments in nanoscale fluid dynamics. He then obtained a Flatiron Research Fellowship and spent a year in New York, learning advanced numerical methods for condensed matter systems. He is now a postdoctoral fellow at the Max Planck Institute for Polymer Research. His research is at the interface between ‘hard’ and ’soft’ condensed matter, focussing on the quantum behavior of liquids near solid surfaces.  

GRK 2516 Soft Matter Seminar
Uni Mainz 14:30 Uhr s.t., Minkowski Room, 05119, Staudingerweg 7 
Leila Saheb Mohamadi, TU Darmstadt, Physics  
TBA  
at Zoom  

GRK 2516 Soft Matter Seminar
Uni Mainz 15:00 Uhr s.t., Minkowski Room, 05119, Staudingerweg 7 
Janka Bauer, JGU, Physics  
TBA  
at Zoom  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Michael E. Flatté, University of Iowa  
Electric manipulation of magnetization is essential for the integration of magnetic functionalities in integrated circuits. Spinorbit torque (SOT), originating from the coupling of electron spin and orbital motion through spinorbital interaction, can effectively manipulate magnetization. Symmetry breaking plays an important role in spintronics based on SOT. SOT requires inversion asymmetry in order to have a net effect on magnetic materials, which is commonly realized by spatial asymmetry: a thin magnetic layer sandwiched between two dissimilar layers. This kind of structure restricts the SOT by mirror and rotational symmetries to have a particular form: an “antidampinglike” component oriented in the film plane even upon reversal of the magnetization direction. Consequently, magnetization perpendicular to the film plane cannot be deterministically switched with pure electric current. To achieve allelectric switching of perpendicular magnetization, it is necessary to break the mirror and rotational symmetries of the sandwiched structure.  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Dr. Gaia Lanfranchi, Frascati, Italy  
With the establishment and maturation of the experimental programs searching for New Physics with sizeable couplings at the LHC, there is an increasing interest in the broader particle and astroparticle community for exploring the physics of light and feeblyinteracting particles (FIPs) as a paradigm complementary to a New Physics sector at the TeV scale and beyond.
SHADOWS is a new experiment proposed at the CERN North Area to search for a large variety of FIPs produced in the interactions of a proton beam with a dump. It will use the 400 GeV primary proton beam extracted from the CERN SPS currently serving the NA62 experiment. SHADOWS can expand the exploration for a large variety of FIPs well beyond the state of the art in the MeVGeV mass range which is allowed by cosmological and astrophysical observations and become one of the main players in the search for FIPs at accelerators in the next decade.
After an introduction about the current plans for searching for FIPs at CERN within the Physics Beyond Colliders activity the referent will present the status of the SHADOWS project.  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Dr. Sarah Köster, Uni Göttingen  
We have about 200 different types of cell in our body, and each of them has very special mechanical properties. Illustrative examples are contracting muscle cells, migrating immune cells or elastic red blood cells. There intriguing mechanical properties are to a great part determined by the socalled cytoskeleton (the “skeleton of the cell”), a composite biopolymer network composed of three filament systems – intermediate filaments, actin filaments and microtubules – along with crosslinkers and molecular motors. In my talk, I will focus on intermediate filaments, the most flexible and the most extensible ones among the different types of filament, with an intriguing nonlinear behavior. It has been shown previously that the presence of intermediate filaments in a cell has an influence on its mechanics. Here we unravel different contributions to network properties and cell mechanics, such as the assembly kinetics and mechanical properties of the individual filaments, filamentfilament interactions, and network rheology. To explain our experimental results on molecular grounds, we design models that include the strictly hierarchical buildup of the filaments and nonequilibrium transitions between folded and unfolded states. Taken together, the experiments and the modelling indicate that intermediate filaments serve as “safety belts” and shock absorbers” for the cell, thus avoiding damage at strong and fast impact, while maintaining flexibility (e.g., during cell motility).  

Seminar about Experimental Particle and Astroparticle Physics (ETAP)
Institut für Physik 12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum 
Johannes Balz, Institut für Physik  
tba  
at Zoom  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Dr. Nico Döttling, Helmholzt Center for Information Security (CISPA) in Saarbrücken  
Quantum Computing and Cryptography  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Dr. Valentina Santoro, ESS, Lund, Sweden  
The European Spallation Source, ESS, currently under construction in Lund, will be the world’s most powerful facility for research using neutrons. Supported by 3MEuro Research and Innovation Action within the EU Horizon 2020 program, a design study (HighNESS) is now underway to develop a second neutron source below the spallation target. Compared to the first source, located above the spallation target and designed for high cold and thermal brightness, the new source will provide a higher intensity (the total number of neutrons from the moderator), and a shift to longer wavelengths in the spectral regions of Cold (410 ˚A), Very Cold (10100 ˚A), and Ultra Cold (> 500 ˚A) neutrons. The core of the second source will consist of a large liquid deuterium moderator to deliver a high flux of cold neutrons and to serve secondary VCN and UCN sources, for which different options are under study. The features of this new source will boost several areas of condensed matter research and will also provide unique opportunities in fundamental physics with the neutron antineutron oscillations experiment NNBAR. This experiment will search for the baryon number violating process of n → ¯n oscillation with a sensitivity of three orders of magnitude over the previously attained limit obtained at the Institut LaueLangevin ILL. As a part of the HighNESS project work is ongoing to deliver the Conceptual Design Report of the experiment.
Concerning the design of the Ultra Cold Neutron and Very cold neutron source for the ESS, a digital workshop has been held from February 2nd to February 4th, 2022 where experts from various laboratories and Universities have gathered to propose and discuss ideas and challenges for the development of these sources. During the course of the workshop, several possibilities have been identified on where to locate the VCN and UCN sources. The UCN source could be placed in close vicinity or at some distance from the primary cold source. Regarding the VCN source, we have identified two possibilities. In the first option, the VCNs are extracted from the main CN source using advanced reflectors. While in the other case we make use of a dedicated VCN converter, for which a material capable of delivering a high flux of VCNs is needed. From the point of view of neutronic performance, two promising materials, which are under study in the HighNESS project, are solid deuterium at about 5 K and deuterated clathrate hydrates at around 2 K. In summary in the the talk, the referent will discuss the HighNESS project, the status of the NNBAR experiment and all
the possibilities for a dedicated UCN and VCN source at the ESS.  

Seminar about Experimental Particle and Astroparticle Physics (ETAP)
Institut für Physik 12:30 Uhr s.t., Staudingerweg 7, Minkowskiraum 
Cloé GiradCarillo, Institut für Physik  
tba  
at Zoom  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Georg von Freymann, TU Kaiserslautern  
Topological photonics and terahertz quantum sensing  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Dr. Anatael Cabrera, Paris, France  
Light Detection and Imaging within Opacity using the Novel LiquidO Technique  

Seminar über Quanten, Atom und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05127 
Prof. Giuseppe Vallone, University of Padova, Italy  
TBA  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Dr. Markus Klute, KIT  
„I think we have it“ – with these words, the then Director General of CERN, RolfDieter Heuer, commented on July 4th, 2012 the detection of a new elementary particle at the Large Hadron Collider (LHC). The search for the Higgs boson, which had lasted almost 50 years, had reached its goal. With the discovery of the Higgs boson, a new era began at the LHC, the precise measurement of the particle's properties. With the help of these properties, conclusions can be drawn about the fundamental structure of the universe and matter. In this colloquium, I will discuss the latest result and prospects in the quest to decipher the Higgs boson.  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Prof. Dr. Peter von Ballmoos, IRAP, Toulouse, France  
Search for antimatter in the universe  

Seminar über Quanten, Atom und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05127 
Prof. Vahid Sandoghdar, MaxPlanckInstitut für die Physik des Lichts, Erlangen  
TBA  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Dr. Philipp SchmidtWellenburg, PSI Switzerland  
Standard Model tests with ultracold neutrons  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Prof. Dr. Steen Hannestad, Univ. Aarhus, Denmark  
Neutrino physics in the era of precision cosmology  

Seminar über Quanten, Atom und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05127 
Prof. Stephan Schiller, HeinrichHeineUniversität Düsseldorf, Institut für Experimentalphysik  
TBA  

Physikalisches Kolloquium
Institut für Kernphysik 16:15 Uhr s.t., HS KPH 
Prof. Dr. Tom Aumann, TU Darmstadt & GSI Darmstadt  
Reactions with shortlived nuclei are key to understand the properties of neutronrich nuclei and neutronrich nuclear matter. In recent years, quasifree scattering experiments have been developed and established for experiments with radioactive beams at GSI and RIKEN. The inverse kinematics of the reaction opens thereby the possibility for a complete characterisation of the final state, which results in an almost backgroundfree measurement. Recent results with stable and radioactive beams will be discussed including the first measurement of shortrange correlations in inverse kinematics, the observation of alpha clusters at the surface of heavy nuclei, as well as the observation of a correlated fourneutron state. The perspective for a precise determination of the neutronneutron scattering length using the 6He(p,p alpha)2n reaction will be discussed as well.  

TheoriePalaver
Institut für Physik 14:00 Uhr s.t., Lorentz room (Staudingerweg 7, 5th floor) 
Weiguang Jiang, JGU Mainz  
TBA  
at Zoom  

PRISMA+ Colloquium
Institut für Physik 13:00 Uhr s.t., LorentzRaum, 05127, Staudingerweg 7 
Prof. Dr. Julien Lesgourges, Aachen  
Hubble tension and possible theoretical solutions  

Seminar über Quanten, Atom und Neutronenphysik (QUANTUM)
Institut für Physik 14:00 Uhr s.t., IPH Lorentzraum 05127 
Prof. Dr. Immanuel Bloch, MaxPlanckInstitute of Quantum Physics, Garching  
TBA  
