GenHET Meeting in Beyond the Standard Model

Session

Lightning talks - 1

25 Feb 2026, 11:10

4/3-006 - TH Conference Room (CERN)

57. Black hole hair transplant with ultra light dark matter

Dhruv Pathak (King's College London)

25/02/2026, 11:10

You can create a black hole bomb using a Kerr black hole by putting mirrors around it. This can happen because of a phenomenon called superradiance using which an incident wave can get reflected back with larger energy. The mirror then reflects it back and you can keep on extracting energy until the limit is reached. For a massive field, the mass itself acts as a natural barrier. Ultra light...

55. Supernovae as Laboratories for sub-GeV Millicharged Particles

Mariachiara Ingicco (Università degli Studi di Padova, INFN Padova)

25/02/2026, 11:20

We study the transport of self-interacting millicharged particles (MCPs) coupled to a massless dark photon in core-collapse supernovae (SNe), focusing on masses above the MeV scale. In this regime, strong self-couplings drive the formation of a relativistic fluid rather than a free-streaming gas. We extend the hydrodynamic framework developed for light MCPs to heavier masses, revisiting...

54. How robust is the QCD axion? A systematic study in a non-minimal model

Fuensanta Viches Bravo (Universidad de Granada)

25/02/2026, 11:30

The axion is one of the most compelling candidates for physics beyond the Standard Model, as it simultaneously provides a solution to the strong CP problem and a viable dark matter candidate. In post-inflationary scenarios, the minimal QCD axion model leads to strong constraints on the axion mass from the dark matter relic abundance. Specific quantization relations hold for the axion-gauge...

41. The Strong-CP Problem and its Gauge Axion Solution as Evidence for Fundamental Strings

Lucy Elisabeth Komisel (Max Planck Institute for Physics & LMU Munich)

25/02/2026, 11:40

The topological susceptibility of the QCD vacuum provides an understanding of θ-vacua as vacua of a Chern-Simons gauge theory. In this way, it gives an immediate proof of the physicality of the boundary θ-term. This makes the essence of the strong-CP puzzle very transparent and offers a solution in form of the gauge axion, which has exact quality. This axion represents an intrinsic part of the...

38. Running Couplings in High-Temperature Effective Field Theory

Mr Andrii Dashko (University of Granada)

25/02/2026, 11:50

In this work, we study the renormalization-group evolution of parameters in the three-dimensional effective field theory (3D EFT) that describes the thermally driven electroweak phase transition of the Higgs field. We focus on the first-order case, triggered by beyond the Standard Model physics.
We compute the two-loop running of the 3D EFT couplings, including the effect of the leading...

44. Hot News on the phase structure of the SMEFT

Maria Cristina Fiore (University of Granada)

25/02/2026, 12:00

We study the high-temperature behavior of the electroweak sector of the Standard Model Effective Field Theory (SMEFT), including dimension-six operators, by performing dimensional reduction up to $\mathcal{O}(g^4)$ in the gauge couplings. Our derivation accounts for one-loop corrections to kinetic terms and scalar quartic couplings, as well as two-loop contributions to thermal mass parameters....

42. How large can lepton mixing be?

Chiara Giuliano (Universidad de Granada)

25/02/2026, 12:10

We show that, contrary to common expectations, the observed charged leptons can have a substantial mixing with new heavier fermions, at the level of 20$\%$.
This can happen, in the language of effective theories, when the effect of mixing with heavier fermions vanishes at tree level in operators of mass-dimension 6 (or it is suppressed by the small charged lepton masses), a cancellation that...