Publications

Order by: publication date number of citations

• Determination of $α_{S}$ beyond $NNLO$ using the event shape averages

  Adam Kardos, Gábor Somogyi, Andrii Verbytskyi

  SciPost Phys. Proc. 10, 014 (2022) · published 10 August 2022 | Toggle abstract · pdf

  In this proceedings we discuss a prescription to extract the QCD strong coupling constant at $N^{3}LO$ precision in perturbative QCD using a combination of ${\cal{O}}(\alpha_{S}^{3})$ calculations in pQCD and estimations of the ${\cal{O}}(\alpha_{S}^{4})$ corrections from the data. The method is applied to a set of event shape averages measured in experiments at the LEP, PETRA, PEP and TRISTAN colliders. In our analysis we account for hadronization effects with models from modern Monte Carlo event generators and analytic hadronization models. We conclude that the precision of the $\alpha_{S}$ extraction cannot be improved significantly only with pQCD predictions of higher orders, and further progress in these studies requires a significant advances in the studies and modeling of hadronization process.

• Algebraic law of local correlations in a driven Rydberg atomic system

  Xin Wang, XiaoFeng Wu, Bo Yang, Bo Zhang, Bo Xiong

  SciPost Phys. 19, 152 (2025) · published 11 December 2025 | Toggle abstract · pdf

  Understanding the mechanism behind the buildup of inner correlations is crucial for studying nonequilibrium dynamics in complex, strongly interacting many-body systems. Here we investigate both analytically and numerically the buildup of antiferromagnetic (AF) correlations in a dynamically tuned Ising model with various geometries, realized in a Rydberg atomic system. Through second-order Magnus expansion (ME), we demonstrate quantitative agreement with numerical simulations for diverse configurations including $2 × n$ lattice and cyclic lattice with a star. We find that the AF correlation magnitude at fixed Manhattan distance obeys a universal superposition principle: It corresponds to the algebraic sum of contributions from all shortest paths. This superposition law remains robust against variations in path equivalence, lattice geometries, and quench protocols, establishing a new paradigm for correlation propagation in quantum simulators.

• Tunable quantum transport in flux-driven designer rings: Role of hopping dimerization, electron filling, and phase architecture

  Souvik Roy, Ranjini Bhattacharya

  SciPost Phys. Core 8, 090 (2025) · published 8 December 2025 | Toggle abstract · pdf

  We explore quantum transport in a one-dimensional Su-Schrieffer-Heeger (SSH) ring threaded by an Aharonov-Bohm flux, incorporating a quasiperiodic site potential based on a generalized cosine modulation with both primary and secondary components. Focusing on spinful, non-interacting electrons, we analyze persistent current behavior across a broad range of filling factors, Aubry-André-Harper (AAH) phase shifts, and hopping dimerizations. Our results uncover a rich interplay of localization-delocalization transitions, driven by the secondary modulation strength, leading to highly tunable and non-monotonic transport signatures. Persistent current is markedly enhanced near the symmetric hopping regime, where quantum interference dominates. In spin-imbalanced configurations, we identify regimes exhibiting pure spin current without net charge flow, suggesting potential for dissipationless spintronic functionalities. To the best of our knowledge, this is the first systematic study to examine quantum transport in such a flux-threaded SSH ring with dual-component quasiperiodic modulations, unifying re-entrant localization, spin-current generation, current stabilization, and phase-selective control. The inverse and normalized participation ratios, together with the state-resolved current, reveal the interplay between eigenstate localization and transport, providing insight into the microscopic mechanisms underlying current suppression and enhancement. For completeness, we also present the system-size dependence of the current. These findings position the quasiperiodic SSH ring as a versatile platform for realizing controllable quantum interference and spin-resolved transport in low-dimensional systems.

• Search for anomalous quartic gauge couplings in the process $\mu^+\mu^-\to \bar{\nu}\nu\gamma\gamma$ with a nested local outlier factor

  Ke-Xin Chen, Yu-Chen Guo, Ji-Chong Yang

  SciPost Phys. Core 8, 091 (2025) · published 11 December 2025 | Toggle abstract · pdf

  In recent years, with the increasing luminosities of colliders, handling the growing amount of data has become a major challenge for future new physics (NP) phenomenological research. To improve efficiency, machine learning algorithms have been introduced into the field of high-energy physics. As a machine learning algorithm, the local outlier factor (LOF), and the nested LOF (NLOF) are potential tools for NP phenomenological studies. In this work, the possibility of searching for the signals of anomalous quartic gauge couplings (aQGCs) at muon colliders using the NLOF is investigated. Taking the process $\mu^+\mu^-\to \nu\bar{\nu}\gamma\gamma$ as an example, the signals of dimension-8 aQGCs are studied, expected coefficient constraints are presented. The event selection strategy uses unsupervised anomaly scores, with supervised optimization for EFT sensitivity. The NLOF algorithm is shown to outperform the k-means based anomaly detection methods, and a traditional counterpart.

• Light meson decays at BESIII

  Xiao Lin Kang

  SciPost Phys. Proc. 10, 007 (2022) · published 10 August 2022 | Toggle abstract · pdf

  The world’s largest sample of J/psi events accumulated at the BESIII detector offers a unique opportunity to investigate eta and eta' physics via two body J/psi radiative or hadronic decays. In recent years the BESIII experiment has made significant progresses in eta/eta' decays. A selection of recent highlights in light meson spectroscopy at BESIII are reviewed in this report, including the observation of eta'->pi+pi-mu+mu-, the study of eta'->pi+pi-e+e-, and search for CP-violation in this decay, search for the rare decays of eta'->4pi0 and eta'->gamma gamma eta, as well as the precision measurement of the branching fraction of eta' decays.

• Fluctuations and Selection Bias in 5 and 13 TeV p-p Collisions: Where are the jets?

  Thomas A. Trainor

  SciPost Phys. Proc. 10, 003 (2022) · published 10 August 2022 | Toggle abstract · pdf

  The ALICE collaboration recently reported high-statistics $\bf p_t$ spectra from 5 TeV and 13 TeV p-p collisions with intent to determine the role of jets in high-multiplicity collisions. In the present study a two-component (soft + hard) model (TCM) of hadron production in p-p collisions is applied to ALICE $\bf p_t$ spectra. As in previous TCM studies of A-B collision systems jet and nonjet contributions to $\bf p_t$ spectra are accurately separated over the entire $\bf p_t$ acceptance. The statistical significance of data-model differences is established leading to insights concerning selection bias and spectrum model validity.

• A family of vertex algebras from Argyres-Douglas theory

  Heeyeon Kim, Jaewon Song

  SciPost Phys. 19, 144 (2025) · published 2 December 2025 | Toggle abstract · pdf

  We find that multiple vertex algebras can arise from a single 4d $\mathcal{N}=2$ superconformal field theory (SCFT). The connection is given by the BPS monodromy operator $M$, which is a wall-crossing invariant quantity that captures the BPS spectrum on the Coulomb branch. For a class of low-rank Argyres-Douglas theories, we find that the trace of the multiple powers of the monodromy operator Tr$M^N$ yield modular functions that can be identified with the vacuum characters of certain vertex algebra for each $N$. In particular, we realize unitary VOAs of the Deligne-Cvitanović exceptional series type $(A_2)_1$, $(G_2)_1$, $(D_4)_1$, $(F_4)_1$, $(E_6)_1$ from Argyres-Douglas theories. We also find the modular invariant characters of the 'intermediate vertex algebras' $(E_{7\frac{1}{2}})_1$ and $(X_1)_1$. Our analysis allows us to construct 3d $\mathcal{N}=2$ gauge theories that flow to $\mathcal{N}=4$ SCFTs in the IR, whose specialized half-index can be identified with these modular invariant characters.

• Hopf exceptional points

  Tsuneya Yoshida, Emil J. Bergholtz, Tomáš Bzdušek

  SciPost Phys. 20, 001 (2026) · published 7 January 2026 | Toggle abstract · pdf

  Exceptional points at which eigenvalues and eigenvectors of non-Hermitian matrices coalesce are ubiquitous in the description of a wide range of platforms from photonic or mechanical metamaterials to open quantum systems. Here, we introduce a class of Hopf exceptional points (HEPs) that are protected by the Hopf invariants (including the higher-dimensional generalizations) and which exhibit phenomenology sharply distinct from conventional exceptional points. Saliently, owing to their $\mathbb{Z}_2$ topological invariant related to the Witten anomaly, three-fold HEPs and symmetry-protected five-fold HEPs act as their own \enquote{antiparticles}. Furthermore, based on higher homotopy groups of spheres, we predict the existence of multifold HEPs and symmetry-protected HEPs with non-Hermitian topology captured by a range of finite groups (such as $\mathbb{Z}_3$, $\mathbb{Z}_{12}$, or $\mathbb{Z}_{24}$) beyond the periodic table of Bernard-LeClair symmetry classes.

• Colouring the Higgs boson

  Andy Buckley, Giuseppe Callea, Andrew J. Larkowski, Simone Marzani

  SciPost Phys. Proc. 10, 001 (2022) · published 10 August 2022 | Toggle abstract · pdf

  The jet colour ring is a novel colour tagger observable designed to separate the decay of a colour-singlet into two jets from a two-jet background in a different colour configuration. Simulation studies in the case of the production of a boosted Higgs boson decaying in two b-quarks and an associate electroweak boson, showed notable discriminator powers when comparing the jet colour ring performances with other observables. These results are opening a wide scenario for further studies.

• Entangled universes

  Divij Gupta, Matthew Headrick, Martin Sasieta

  SciPost Phys. 19, 143 (2025) · published 1 December 2025 | Toggle abstract · pdf

  We propose a generalization of the RT and HRT holographic entanglement entropy formulas to spacetimes with asymptotically Minkowski as well as asymptotically AdS regions. We postulate that such spacetimes represent entangled states in a tensor product of Hilbert spaces, each corresponding to one asymptotic region. We show that our conjectured formula has the same general properties and passes the same general tests as the standard HRT formula. We provide further evidence for it by showing that in many cases the Minkowski asymptotic regions can be replaced by AdS ones using a domain wall. We illustrate the use of our formula by calculating entanglement entropies between asymptotic regions in Brill-Lindquist spacetimes, finding phase transitions similar to those known to occur in AdS. We construct networks of universes by gluing together Brill-Lindquist spaces along minimal surfaces. Finally, we discuss a variety of possible extensions and generalizations, including to universes with asymptotically de Sitter regions; in the latter case, we identify an ambiguity in the homology condition, leading to two different versions of the HRT formula which we call "orthodox" and "heterodox", with different physical interpretations.