arXiv subjects

Andrii Zaporozhchenko

Publications and source records attributed to Andrii Zaporozhchenko.

3 recordsLinked to original sources

arXiv2026

Effects of Curvature-Scalar Coupling on Vacuum Energy in Flat (3+1)-Dimensional Space-Time

We investigated how a magnetic topological defect affects the vacuum polarization of a charged massive scalar field in a flat $(3+1)$-dimensional space-time. The defect was modeled as an impenetrable to matter field finite-thickness tube with magnetic flux inside. We implemented the most general form of the Robin boundary condition on the surface of the magnetic tube, which enables a fully general analysis of the problem. We have found that in flat spacetime, the total vacuum energy generated by a magnetic topological defect depends on the curvature $ξ$, except for special cases corresponding to the Dirichlet and Neumann boundary conditions. By contrast, when Robin's general boundary conditions are imposed, the induced vacuum energy acquires an explicit dependence on the curvature coupling $ξ$, which is significant even in flat space-time. A detailed study of the dependence of the effect on the boundary condition parameter has been carried out. The obtained results highlight the nontrivial role played by boundary conditions in vacuum polarization phenomena.

hep-th↗

arXiv2026

Advancing the phenomenology of GeV-scale axion-like particles

Searches for axion-like particles (ALPs) with masses in the GeV range are a central objective of present and future Intensity Frontier experiments. Interpreting these searches demands a reliable description of ALP production in hadronic collisions and decay. The prescription currently adopted by the community (i) depends on parameters of unphysical chiral rotation used to match gluonic ALP interactions with the interactions in terms of hadronic bound states, (ii) misdescribes the mass scaling of the ALP flux, and neglects mixing with heavy pseudoscalar resonances. We introduce a framework that treats GeV-scale ALP interactions in a chiral-rotation-invariant manner, includes their mixing with heavier excitations $π(1300)$, $η(1295)$, and $η(1440)$, and properly describes their production channels. When applying our description to proton beam experiments, we find that existing bounds and projected sensitivities shift by up to an order of magnitude relative to earlier estimates. We further delineate the dominant theoretical uncertainties, which originate from the still-incomplete experimental knowledge of the spectrum of pseudoscalar excitations.

hep-ph↗

arXiv2024

Phenomenology of axion-like particles with universal fermion couplings -- revisited

Axion-like particles (ALPs) emerge in many extensions of the Standard Model as pseudo-Goldstone bosons of a spontaneously broken global symmetry. Understanding their phenomenology in high-energy collisions is crucial for optimizing experimental searches and understanding the exploration potential of future experiments. In this paper, we revise the phenomenology of ALPs with universal couplings to fermions. In particular, we analyze the hierarchy and uncertainty of the various ALP production channels depending on the proton collision energy and the placement of the experiment, and provide improved calculations of the hadronic decay modes.

hep-ph↗