axions++ 2023

Session

HEP - Phenomenology

28 sept. 2023, 09:00

Auditorium Vivargent (LAPTh)

48. EFT aspects of axions and other light particles

Maria Ramos (UAM/IFT), Maria Ramos

28/09/2023 09:00

17. Constraining ALP couplings using SMEFT-interference

Anne Mareike Galda (Johannes Gutenberg University Mainz)

28/09/2023 09:30

Axions and axion-like particles (ALPs) are pseudo Nambu-Goldstone bosons interacting with the SM fields via classically shift-invariant operators starting at dimension-5. Loop diagrams where the ALP is present as a virtual particle are generally UV-divergent and require renormalization. Consequently, dimension-6 SMEFT operators are generated as counterterms at the scale of global symmetry...

37. Axion effective action

Dr Pham Ngoc Hoa Vuong (DESY)

28/09/2023 10:00

We present the construction of Effective Field Theories (EFTs) in which a chiral fermion, charged under both gauge and global symmetries, is integrated out via Path Integral formalism. These symmetries can be spontaneously broken, and the global ones might also be anomalous. This setting is typically served to study the structure of low-energy axion EFTs, where the anomalous global symmetry...

18. Axion-photon coupling from lattice QCD

José Javier Hernández Hernández (University of Bielefeld)

28/09/2023 10:50

We present preliminary results for the QCD contribution to the axion-photon coupling obtained via lattice simulations. For sufficiently small background electromagnetic fields, the topological charge exhibits a linear response to the scalar product between E and B, whose slope can be interpreted as the axion-photon coupling. The reasons for this interpretation are explained. In order to...

32. Shift-Invariant Orders of an Axionlike Particle

Jonathan Kley (DESY)

28/09/2023 11:10

Usually, effective field theories (EFTs) for axion-like particles (ALPs) are built assuming a shift symmetry for the ALP due to the global U(1) Peccei-Quinn (PQ) symmetry that is at the heart of the axion mechanism. However, it is generally believed that global symmetries, in particular axion shift symmetries, can only be approximate. Therefore, it is important to include shift-breaking...

29. How to Measure the Spin of Dark Matter in $e^+ e^- \to \gamma + X$

Sofie Nordahl Erner (Durham University)

28/09/2023 11:30

Dark Matter has eluded us for decades and continues to do so. Currently lepton colliders provide exclusion limits on individual dark matter models, but many models may have either identical or indistinguishable signals. Hence there is a need for new methods or observables to determine the nature of the dark matter, especially if more than one candidate is present. Using $e^+ e^-$ processes...

24. King Fits: Global bounds on light new physics from isotope shifts

Fiona Kirk (PTB Braunschweig), Fiona Kirk

28/09/2023 11:50

Isotope shift frequencies figure among the most precisely measured physical quantities but are highly challenging to predict from first principles. In recent years King plots emerged as powerful data-driven tools that eliminate the theoretical uncertainties on the Standard Model nuclear parameters and can place bounds on new light mediators between neutrons and electrons.
We develop a...