PRISMA Colloquium

Dealing with diversity is structurally anchored in most universities. In public discourse or in work contexts, a distinction is usually only made between the dimensions of diversity specified in the General Equal Treatment Act, such as e.g. age, gender, disabilities. One dimension that is often forgotten, but which is no less relevant for the future of work and our society, is neurodiversity. Neurodiversity means normalizing differences in people's mental states and not dividing them into “mentally ill” and “mentally healthy”. Here, Dr. Simone Burel also reports from her own experience and tells us about different types of neurodiversity (including impostor syndrome, depression, social phobia, anxiety disorder, panic disorder). She will open for us her treasure chest with tips and tricks to realize potential of neurodiverse persons.
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This talk will explore the physics potential of the Future Circular Collider (FCC), a proposed particle accelerator at CERN, capable of reaching energies and luminosities beyond the capabilities of current machines. We will discuss the FCC’s ability to probe the Standard Model with higher precision, its unique potential to explore the Higgs boson and discover new particles, and its role in addressing open questions in particle physics. The talk will illustrate how the FCC could shape our understanding of the universe at its most fundamental level. Link to presentation slides: https://www.dropbox.com/scl/fi/9l1v2wfsphp7glg9p42ku/2024-10-30-fcc.pdf?rlkey=jsxyz2tfi0bu6of99uofa2yc8&e=1&st=0j7yckpi&dl=0
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Calorimeters play a pivotal role in past, present and future experiments in particle physics. Final states of particle physics collision consist to a large fraction of jets. These jets are composed of electrons, photons and charged and neutral hadrons. A central requirement to meet scientific goals at future experiments is to keep the jet energy resolution at a level of 3-4% for jet energies between 45 GeV and around a TeV (or more). There are several proposal to meet this goal, by increasing the granularity of the calorimeters by dedicated precise measurements of hadrons and electromagnetic particles within a jet or by a combination of these features. This seminar will review the requirements to calorimeters in future experiments and the status and outlook on the current R&D to meet these requirements. The seminar will also sketch the potential to apply machine learning for calorimetry and how quantum sensing may dramatically change the design of future calorimeters. Slides: https://docs.google.com/presentation/d/1P0fRA6z8l1XNLxh8bBXHHB0a90VHrjt63EOvA7wNEFg/edit?usp=sharing
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I will start with a brief introduction to the UV-problems of gravity and how string theory proposes to resolve them. As we will see, this implies extra dimensions and hence the possibility of different "compactifications", leading to very many possible 4d theories. The idea that more or less any 4d model can be found in this huge "Landscape" has more recently been challenged by the "Swampland" paradigm, proposing to search for general criteria for what can or can not occur in 4d effective theories having a consistent UV completion in quantum gravity. I will discuss some of the most important such "Swampland Conjectures": The "No-Global Symmetries", "Weak Gravity" and "Distance Conjecture". Finally, I will briefly review the phenomenologically very important but less established "de Sitter Conjecture".
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The talk will give an overview of LHC probes of Axion-Like Particles (ALPs), whose couplings are parameterized via effective interactions of dimension larger than 5. The first part will introduce the main motivations for studying ALPs and it will discuss the main properties of the ALP EFT, while the second will be dedicated to phenomenological aspects. This will contain a general overview of how ALPs can be searched at colliders, as well as brief discussions of theory constraints stemming from perturbative unitarity and of recent new ideas brought forward in the field, such as the use of non-resonant ALP production in constraining ALP couplings to heavy SM states, and the exploration of ALP couplings beyond dimension-5.
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The mass of the W boson, the mediator of the charged weak interaction, can be predicted with a relative precision of about 80 ppm within the Standard Model (SM) of particle physics. The existence of new physics could however affect the W boson mass via quantum loops and shift it with respect to the SM prediction. Thus, a direct measurement of the W mass can be both a sensitive test of consistency of the theory as well as a window to new physics. In this respect, great interest, together with confusion, was raised by the measurement delivered by the CDF Collaboration in 2022 which, besides being the most precise measurement to date, is in disagreement with the SM and also barely consistent with previous measurements. Up until recently, the CMS experiment was the last missing contributor to the W mass effort. The new result by CMS which I will present in this seminar is based on a partial sample of LHC proton-proton collision data collected during the 2016 data-taking period. The W boson mass is extracted using single-muon events via a highly granular maximum likelihood fit of the muon kinematics split by charge and by relying on state-of-the-art tools for the modeling of W boson production and decay. This novel approach enables significant in-situ constraints of experimental and theoretical uncertainties. The CMS result has an uncertainty comparable to the CDF measurement and agrees with the SM. It represents a crucial step in solving the W boson mass puzzle.
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Nearly 70 years since the neutrino was discovered, and 25 years since discovery of neutrino oscillations established its non-zero mass, the absolute neutrino-mass scale remains unknown. Tritium beta decay endpoint measurements currently offer the best upper limit on the neutrino mass. A next-generation experiment with greater sensitivity must overcome one of the major systematics for this kind of measurement: the molecular nature of the beta source. Past and current tritium beta decay experiments use a molecular tritium source in which one of the tritium atoms undergoes decay. A fraction of the decay energy excites the molecule into rotational, vibrational, or electronic excited states; this causes broadening in the molecule's final state distribution (FSD), and has a smearing effect on the beta decay spectrum. In order to achieve a reduced systematic uncertainty due to this FSD smearing, next-generation experiments must switch to an atomic tritium source. I will present an overview of the necessary steps to develop such an atomic tritium source, through the lens of the Project 8 experiment. This multi-institution development program includes dissociation and accommodation cooling down to 10K; further cooling to 10mK via magnetic evaporative cooling; and atom trapping using magnet arrays. In addition to this overview, I will focus on the multitude of tritium-compatible diagnostic tools being developed at JGU Mainz to measure atom flux, atom beam shape, and temperature.
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For decades, we have been looking for Dark Matter in the form of WIMPs, but many other possibilities exist. Light DM, intended as having a mass between 1 MeV and about 1 GeV, is one of these possibilities, which is interesting both theoretically and phenomenologically. Testing it via Indirect Detection is more challenging than WIMPs, but X-ray measurements provide a very powerful handle. They currently impose stringent constraints, and allow in perspective to explore further this relatively new region of the parameter space.
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A decade has passed since the groundbreaking detection of gravitational waves, significantly advancing our understanding of the cosmos. While most current research focuses on detecting gravitational waves at frequencies below a few kHz, there is a growing interest in exploring higher-frequency signals, particularly those of cosmological origin. In the first part of my talk, I will explore the background for these signals within the Standard Model, with a focus on the primary source on Earth: the Sun's high-temperature plasma. I will draw a notable connection to solar axions. In the second part, the discussion will turn to experimental approaches for detecting high-frequency gravitational waves, with particular attention to the potential of axion haloscopes as well polarimetry techniques.