Publications

Order by: publication date number of citations

• MEG final results and progress towards MEG II

  Toshiyuki Iwamoto on behalf of the MEG II collaboration

  SciPost Phys. Proc. 1, 040 (2019) · published 21 February 2019 | Toggle abstract · pdf

  The MEG experiment, which is to search for lepton flavor violating muon decay, had been successfully finished in 2013. The final sensitivity of the experiment was 5.3 × 10−13, and since the experiment did not find any signal, the upper limit of the branching ratio of the μ+ → e+γ was set to be 4.2 × 10−13 at 90% CL. The MEG II experiment will improve the sensitivity by an order of magnitude with three years data taking, and the target sensitivity is 6×10−14. In 2018 after the detector integration, the muon beam data taking will be planned with limited number of readout channels. In 2019, the engineering run and the physics run will be started.

• Momentum transfer dependence of heavy quarkonium electroproduction

  Michal Krelina, Jan Nemchik

  SciPost Phys. Proc. 8, 114 (2022) · published 13 July 2022 | Toggle abstract · pdf

  We investigate the momentum transfer dependence of differential cross sections $d\sigma/dt$ in diffractive electroproduction of heavy quarkonia on proton targets. Model predictions for $d\sigma/dt$ within the light-front QCD dipole formalism are based on a realistic model for a proper correlation between the impact parameter $\vec b$ of a collision and color dipole orientation $\vec r$. We demonstrate a significance of $\vec b-\vec r$ correlation by comparing with a standard simplification $\vec{b}\parallel\vec{r}$, frequently used in the literature.

• Jordan meets Freudenthal. A black hole exceptional story

  Alessio Marrani

  SciPost Phys. Proc. 14, 009 (2023) · published 23 November 2023 | Toggle abstract · pdf

  Within the extremal black hole attractors arising in ungauged $\mathcal{N}≥ 2$-extended Maxwell Einstein supergravity theories in $3+1$ space-time dimensions, we provide an overview of the stratification of the electric-magnetic charge representation space into "large" orbits and related "moduli spaces", under the action of the (continuous limit of the) non-compact $U$-duality Lie group. While each "large" orbit of the $U$-duality supports a class of attractors, the corresponding " moduli space" is the proper subspace of the scalar manifold spanned by those scalar fields on which the Attractor Mechanism is inactive. We present the case study concerning $\mathcal{N}=2$ supergravity theories with symmetric vector multiplets' scalar manifold, which in all cases (with the exception of the minimally coupled models) have the electric-magnetic charge representation of $U$-duality fitting into a reduced Freudenthal triple system over a cubic (simple or semi-simple) Jordan algebra.

• Approaching the first any light particle search II science run

  Aaron D. Spector for the ALPS Collaboration

  SciPost Phys. Proc. 12, 039 (2023) · published 4 July 2023 | Toggle abstract · pdf

  The Any Light Particle Search II (ALPS II) is a light-shining-through-a-wall (LSW) experiment based at DESY in Hamburg, Germany, that will search for axions and axion-like particles down to the coupling of the axion to two photons of $g_{a\gamma\gamma}$ >2$\times10^{-11}$ GeV$^{-1}$ for masses below 0.1 meV. ALPS II will use two strings of superconducting dipole magnets that are over one hundred meters in length, as well as optical cavities before and after the wall to boost the effective signal rate of the regenerated photons by more than 12 orders of magnitude when compared to previous generations of LSW experiments. Data taking with a simplified optical system is expected to begin in early 2023.

• Area law and OPE blocks in conformal field theory

  Jiang Long

  SciPost Phys. Proc. 4, 013 (2021) · published 13 August 2021 | Toggle abstract · pdf

  This is an introduction to the relationship between area law and OPE blocks in conformal field theory.

• Dynamical mean field theory for models of confluent tissues and beyond

  Persia Jana Kamali, Pierfrancesco Urbani

  SciPost Phys. 15, 219 (2023) · published 30 November 2023 | Toggle abstract · pdf

  We consider a recently proposed model to understand the rigidity transition in confluent tissues and we derive the dynamical mean field theory (DMFT) equations that describes several types of dynamics of the model in the thermodynamic limit: gradient descent, thermal Langevin noise and active drive. In particular we focus on gradient descent dynamics and we integrate numerically the corresponding DMFT equations. In this case we show that gradient descent is blind to the zero temperature replica symmetry breaking (RSB) transition point. This means that, even if the Gibbs measure in the zero temperature limit displays RSB, this algorithm is able to find its way to a zero energy configuration. We include a discussion on possible extensions of the DMFT derivation to study problems rooted in high-dimensional regression and optimization via the square loss function.

• Axion-like particle as cold dark matter via the misalignment mechanism with PQ symmetry unbroken during inflation

  Pawel Kozow, Marek Olechowski

  SciPost Phys. Proc. 12, 038 (2023) · published 4 July 2023 | Toggle abstract · pdf

  The QCD axion and axion-like particles (ALPs) are well motivated candidates for Cold Dark Matter (CDM). Such models may be divided into two classes depending on whether the associated Peccei-Quinn (PQ) symmetry is broken or not during inflation. The latter case is usually considered to be quite simple with relic density depending only on the corresponding decay constant and with no constraints from the known bounds on isocurvature perturbations. We will show that the situation is much more complicated. We will discuss conditions which should be fulfilled by ALP models with U(1) unbroken during inflation to be phenomenologically interesting.

• Probing ALPs at the LUXE experiment

  Federico Meloni on behalf of the LUXE collaboration

  SciPost Phys. Proc. 12, 037 (2023) · published 4 July 2023 | Toggle abstract · pdf

  The proposed LUXE experiment (LASER Und XFEL Experiment) at DESY, Hamburg, aims to probe QED in its non-perturbative regime. In order to do this, LUXE will study the interactions between 16.5 GeV electrons from the European XFEL and high-intensity laser pulses. This experiment also provides a unique opportunity to probe physics beyond the Standard Model: exploiting the large photon flux generated at LUXE, it is possible to design a dedicated detector to probe axion-like-particles up to a mass of 350 MeV and with photon coupling of $3 \cdot 10^{-6}$ GeV$^{-1}$. This reach is comparable to the projected sensitivity of experiments like FASER2 at the HL-LHC and NA62 operating in dump mode.