Publications

Order by: publication date number of citations

• SU(3) hybrid static potentials at small quark-antiquark separations from fine lattices

  Carolin Schlosser, Marc Wagner

  SciPost Phys. Proc. 6, 009 (2022) · published 31 May 2022 | Toggle abstract · pdf

  We summarize our recent lattice gauge theory computation of the $\Pi_u$ and $\Sigma_u^-$ hybrid static potentials at small quark-antiquark separations. We provide parameterizations of the resulting lattice data points, which can be used for investigating masses and properties of heavy hybrid mesons in the Born-Oppenheimer approximation.

• Quantum Monte Carlo simulation of the 3D Ising transition on the fuzzy sphere

  Johannes Stephan Hofmann, Florian Goth, Wei Zhu, Yin-Chen He, Emilie Huffman

  SciPost Phys. Core 7, 028 (2024) · published 9 May 2024 | Toggle abstract · pdf

  We present a numerical quantum Monte Carlo (QMC) method for simulating the 3D phase transition on the recently proposed fuzzy sphere [Phys. Rev. X 13, 021009 (2023)]. By introducing an additional SU(2) layer degree of freedom, we reformulate the model into a form suitable for sign-problem-free QMC simulation. From the finite-size-scaling, we show that this QMC-friendly model undergoes a quantum phase transition belonging to the 3D Ising universality class, and at the critical point we compute the scaling dimensions from the state-operator correspondence, which largely agrees with the prediction from the conformal field theory. These results pave the way to construct sign-problem-free models for QMC simulations on the fuzzy sphere, which could advance the future study on more sophisticated criticalities.

• Strengthening the atom-field coupling through the deep-strong regime via pseudo-Hermitian Hamiltonians

  M. A. de Ponte, F. Oliveira Neto, P. M. Soares, M. H. Y. Moussa

  SciPost Phys. 15, 091 (2023) · published 13 September 2023 | Toggle abstract · pdf

  We present a strategy for strengthening the atom-field interaction through a pseudo-Hermitian Jaynes-Cummings Hamiltonian. Apart from the engineering of an effective non-Hermitian Hamiltonian, our strategy also relies on the accomplishment of short-time measurements on canonically conjugate variables. The resulting fast Rabi oscillations may be used for many quantum optics purposes and specially to shorten the processing time of quantum information.

• Electronic structure of CeAuAl$_3$ using density functional theory

  André Deyerling, Marc A. Wilde, Christian Pfleiderer

  SciPost Phys. Proc. 11, 008 (2023) · published 5 June 2023 | Toggle abstract · pdf

  We studied the magnetic properties and electronic structure of $CeAuAl_3$ using density functional theory. This compound shows a large Sommerfeld coefficient, a Kondo temperature, ${T_K=4\,K}$ and antiferromagnetic order below ${T_N=1.1\,K}$. We calculated the magnetic groundstate of ${CeAuAl_3}$ and the magnetic anisotropy energies. Treating the 4f-electrons as localized with DFT+U we obtain a good match with the magnetic properties observed experimentally. We also report salient features of the electronic structure of ${CeAuAl_3}$, including features of the Fermi surface and associated quantum oscillatory spectra, when the 4f-electrons are treated either as localized or itinerant.

• Intermittency analysis of charged particles generated in Xe-Xe~collisions at $\sqrt{s_{\rm{NN}}}$ = 5.44 TeV using the AMPT model

  Zarina Banoo, Ramni Gupta

  SciPost Phys. Proc. 15, 010 (2024) · published 2 April 2024 | Toggle abstract · pdf

  The multiplicity fluctuations are sensitive to QCD phase transition and to the presence of critical point in QCD phase diagram. At critical point a system undergoing phase transition is characterized by large fluctuations in the observables which is an important tool to understand the dynamics of particle production in heavy-ion interactions and phase changes. Multiplicity fluctuations of produced particles is an important observable to characterize the evolving system. Using scaling exponent obtained from the normalized factorial moments of the number of charged hadrons in the two dimensional ($\eta,\phi$) phase space, one can learn about the dynamics of system created in these collisions. Events generated using Xe-Xe collisions at $\sqrt{s_{\rm{NN}}} = 5.44 $ TeV with string-melting (SM) version of the AMPT model are analyzed and the scaling exponent $(\nu)$ for various $p_T$ intervals is determined. It is observed that the calculated value of $\nu$ is larger than the universal value 1.304, as is obtained from Ginzburg-Landau theory for second order phase transition. Here we will also present the results of the dependence of the scaling exponent on the transverse momentum bin width.

• Implications of exclusive J/$\psi$ photoproduction in a tamed collinear factorisation approach to NLO

  Chris A. Flett, Alan D. Martin, Misha G. Ryskin, Thomas Teubner

  SciPost Phys. Proc. 15, 005 (2024) · published 2 April 2024 | Toggle abstract · pdf

  We discuss exclusive J/$\psi$ photoproduction, initially in conventional collinear factorisation at NLO and then subsequently in a refined approach with a programme of low x resummation and implementation of a crucial low $Q_0$ subtraction included. We compare and contrast predictions in both frameworks and remark about the possibility to constrain and ultimately determine the low x and low scale gluon PDF, emphasising the significance of this for future global PDF analyses.

• Brick wall quantum circuits with global fermionic symmetry

  Pietro Richelli, Kareljan Schoutens, Alberto Zorzato

  SciPost Phys. 17, 087 (2024) · published 23 September 2024 | Toggle abstract · pdf

  We study brick wall quantum circuits enjoying a global fermionic symmetry. The constituent 2-qubit gate, and its fermionic symmetry, derive from a 2-particle scattering matrix in integrable, supersymmetric quantum field theory in 1+1 dimensions. Our 2-qubit gate, as a function of three free parameters, is of so-called free fermionic or matchgate form, allowing us to derive the spectral structure of both the brick wall unitary $U_F$ and its, non-trivial, Hamiltonian limit $H_{\gamma}$ in closed form. We find that the fermionic symmetry pins $H_{\gamma}$ to a surface of critical points, whereas breaking that symmetry leads to non-trivial topological phases. We briefly explore quench dynamics for this class of circuits.

• Thermodynamics of adiabatic quantum pumping in quantum dots

  Daniele Nello, Alessandro Silva

  SciPost Phys. Core 7, 067 (2024) · published 4 October 2024 | Toggle abstract · pdf

  We consider adiabatic quantum pumping through a resonant level model, a single-level quantum dot connected to two fermionic leads. Using the tools of adiabatic expansion, we develop a self-contained thermodynamic description of this model accounting for the variation of the energy level of the dot and the tunnelling rates with the thermal baths. This enables us to study various examples of pumping cycles computing the relevant thermodynamic quantities, such as the entropy produced and the dissipated power. These quantities are compared with the transport properties of the system, i.e. the pumped charge and the charge noise. Among other results, we find that the entropy production rate vanishes in the charge quantization limit while the dissipated power is quantized in the same limit.

• Mixed QCD-electroweak corrections to $Z$ and $W$ boson production and their impact on the $W$ mass measurements at the LHC

  Arnd Behring

  SciPost Phys. Proc. 7, 003 (2022) · published 20 June 2022 | Toggle abstract · pdf

  We report on recently computed mixed QCD-electroweak corrections to on-shell $W$ and $Z$ boson production. We use these differential predictions to estimate their impact on the $W$ boson mass determination at the LHC.

• Experimental input from $e^+e^-$ for $a_{\mu}$ light-by-light

  Yuping Guo on behalf of BESIII Collaboration

  SciPost Phys. Proc. 1, 054 (2019) · published 9 May 2019 | Toggle abstract · pdf

  The anomalous magnetic momentum of the muon, $a_{\mu}$, has been measured and calculated with a precision up to $~0.5$ ppm, but there is a 3 to 4 standard deviations between these two values. The uncertainty in the calculation is dominated by the hadronic part, including the hadronic vacuum polarization and the hadronic light-by-light. The meson transition form factors and the helicity amplitudes can be used as input or constraint to the calculation of the hadronic light-by-light contribution. Latest experimental studies of the transition form factors of $\pi^0$, $\eta$, and $\eta^{*}$ and the cross-section of $\gamma\gamma^*\to\pi^+\pi-$from $e^+e^-$ collider are presented.