Publications

Order by: publication date number of citations

• Production mechanisms of open heavy flavor mesons in high-multiplicity events

  Marat Siddikov, Ivan Schmidt

  SciPost Phys. Proc. 8, 096 (2022) · published 13 July 2022 | Toggle abstract · pdf

  In this proceeding we discuss different mechanisms of open-heavy flavor meson production which contribute to inclusive and single diffractive cross-sections. For the case of inclusive production we demonstrate that the three-Pomeron fusion is significant for the $D$-meson production in the kinematics of small transverse momenta $p_{T}$, as well as in large-multiplicity events. Its inclusion allows to improve significantly the description of experimental data. We also analyzed the diffractive production and found that due to gap survival factors it constitutes 0.5\textendash 2 per cent of the inclusive production. The expected dependence on event multiplicity in this channel is significantly milder than for inclusive case.

• Air showers and hadronic interactions with CORSIKA 8

  Maximilian Reininghaus

  SciPost Phys. Proc. 15, 019 (2024) · published 3 April 2024 | Toggle abstract · pdf

  The CORSIKA 8 project is a collaborative effort aiming to develop a versatile C++ framework for the simulation of extensive air showers, intended to eventually succeed the long-standing FORTRAN version. I present an overview of its current capabilities, focusing on aspects concerning the hadronic and muonic shower components. In particular, I demonstrate the "cascade lineage" feature and its application to quantify the importance of certain phase-space regions in hadronic interactions for muon production. Additionally, I show first results using Pythia 8.3, which as of late is usable as interaction model in cosmic-ray applications and is currently being integrated into CORSIKA 8.

• Pion electronic decay and lepton universality

  D. Počanić

  SciPost Phys. Proc. 5, 025 (2021) · published 6 September 2021 | Toggle abstract · pdf

  In common with a number of simple processes involving elementary particles, charged pion decays are profoundly shaped by applicable Standard Model (SM) symmetries and properties. Given the highly precise SM theoretical description, pion decays are used as selective probes of SM parameters, and of possible SM extensions. The PEN experiment at PSI is studying the π + → e + ν e (γ), or π_ e2(γ) decay. The primary goal is to reach the relative precision of 5 × 10 ^{−4} in Re/μ^π, the branching ratio for π_ e2(γ) decay. We review the PEN research program, its present status, and prospects.

• ATLAS Results with Beauty Mesons

  Ann-Kathrin Perrevoort

  SciPost Phys. Proc. 8, 099 (2022) · published 13 July 2022 | Toggle abstract · pdf

  A broad range of measurements involving $B$ mesons are performed with the ATLAS experiment at the Large Hadron Collider, of which a selection is discussed in this note. This includes a measurement of the relative $B_c^\pm$ to $B^\pm$ production cross section in $pp$ collisions at a centre-of-mass energy $\sqrt{s}$ of 8 TeV, as well as the latest results on the branching ratios of the rare decays $B^0_s\to\mu^+\mu^-$ and $B^0\to\mu^+\mu^-$ using $pp$ collisions recorded at $\sqrt{s}=$ 7, 8 and 13 TeV. Furthermore, accurate measurements of mixing and CP violation in $B_s^0 \to J/\psi\, \phi$ decays are performed. The latest results on the CP violating phase $\phi_s$ and other parameters describing the decay obtained at $\sqrt{s}=$ 7, 8 and 13 TeV are reported.

• Longitudinal double-spin asymmetries of inclusive jet and dijet production at STAR

  Maria Zurek

  SciPost Phys. Proc. 8, 086 (2022) · published 12 July 2022 | Toggle abstract · pdf

  At the STAR experiment, the gluon helicity distribution $\Delta g(x, Q^2)$ can be accessed through the double-spin asymmetries $A_{LL}$ of inclusive jet and dijet production in collisions of longitudinally polarized protons. These proceedings report on recently published results of $A_{LL}$ for inclusive jets and dijets at $\sqrt{s} = 200$~GeV and $\sqrt{s} = 510$ GeV in mid-pseudorapidity ($|\eta| < 1$) and preliminary results for dijets in intermediate pseudrapidity ($-0.8 < \eta < 1.8$). The mid-pseudorapidity jet and dijet measurements are sensitive to $\Delta g(x, Q^2)$ for gluon momentum fractions $x$ from $\simeq 0.5$ down to $\simeq 0.015$; the sensitivity region for dijets in intermediate pseudorapidity at 510 GeV extends to even lower $x$. The measurements are in good agreement with previous STAR results and recent theoretical evaluations of prior world data.

• A pitfall in applying non-anticommuting $γ_5$ in $q\overline{q} \rightarrow ZH$ amplitudes

  Taushif Ahmed

  SciPost Phys. Proc. 7, 008 (2022) · published 20 June 2022 | Toggle abstract · pdf

  In computing the two-loop QCD corrections to a class of Feynman diagrams for the process $q\overline{q} \rightarrow ZH$ in Higgs effective field theory, we discover a striking phenomenon. We find the need for an additional local composite operator in the renormalised Lagrangian while employing a non-anticommuting $\gamma_5$ in dimensional regularisation. The computation using anticommuting $\gamma_5$, however, does not require any such amendment.

• Critical dynamics and cyclic memory retrieval in non-reciprocal Hopfield networks

  Shuyue Xue, Mohammad Maghrebi, George I. Mias, Carlo Piermarocchi

  SciPost Phys. 19, 100 (2025) · published 16 October 2025 | Toggle abstract · pdf

  We study Hopfield networks with non-reciprocal coupling inducing switches between memory patterns. Dynamical phase transitions occur between phases of no memory retrieval, retrieval of multiple point-attractors, and limit-cycles. The limit cycle phase is bounded by a Hopf bifurcation line and a fold bifurcation line. Autocorrelation scales as $\tilde{C}(\tau/N^\zeta)$, with $\zeta = 1/2$ on the Hopf line and $\zeta = 1/3$ on the fold line. Perturbations of strength $F$ on the Hopf line exhibit response times scaling as $|F|^{-2/3}$, while they induce switches in a controlled way within times scaling as $|F|^{-1/2}$ in the fold line. A Master Equation approach numerically verifies the critical behavior predicted analytically. We discuss how these networks could model biological processes near a critical threshold of cyclic instability evolving through multi-step transitions.

• Sequential adiabatic generation of chiral topological states

  Xie Chen, Michael Hermele, David T. Stephen

  SciPost Phys. 19, 107 (2025) · published 23 October 2025 | Toggle abstract · pdf

  In previous work, it was shown that non-trivial gapped states can be generated from a product state using a sequential quantum circuit. Explicit circuit constructions were given for a variety of gapped states at exactly solvable fixed points. In this paper, we show that a similar generation procedure can be established for chiral topological states as well, despite the fact that they lack a zero-correlation-length exactly solvable form. Instead of sequentially applying local unitary gates, we sequentially evolve the Hamiltonian by changing local terms in one subregion and then the next. The Hamiltonian remains gapped throughout the process, giving rise to an adiabatic evolution mapping the ground state from a product state to a chiral topological state. We demonstrate such a sequential adiabatic generation process for free fermion chiral states like the Chern Insulator and the $p+ip$ superconductor. Moreover, we show that coupling a quantum state to a discrete gauge group can be achieved through a sequential quantum circuit, thereby generating interacting chiral topological states from the free fermion ones.

• All order merging of high energy and soft collinear resummation

  Jeppe R. Andersen, Hitham Hassan, Sebastian Jaskiewicz

  SciPost Phys. Proc. 15, 022 (2024) · published 3 April 2024 | Toggle abstract · pdf

  We present a method of merging the exclusive LO-matched high energy resummation of High Energy Jets (HEJ) with the parton shower of PYTHIA which preserves the accuracy of the LO cross sections and the logarithmic accuracy of both resummation schemes across all of phase space. Predictions produced with this merging prescription are presented with comparisons to data from experimental studies and suggestions are made for further observables and experimental cuts which highlight the importance of both high energy and soft-collinear effects.

• Helix string fragmentation and charged particle correlations with ATLAS

  Šárka Todorova-Nová

  SciPost Phys. Proc. 15, 023 (2024) · published 3 April 2024 | Toggle abstract · pdf

  Correlations between charged particles provide important insight into the hadronization process. The analysis of the momentum difference between charged hadrons in pp, p-lead, and lead-lead collisions at LHC is performed by the ATLAS Collaboration in order to study the dynamics of hadron formation. The spectra of correlated hadron chains are explored and compared to the predictions based on the quantized fragmentation of a three dimensional QCD helix string. This provides an alternative view of the two-particle correlation phenomenon typically attributed to the Bose-Einstein interference.