Publications

Order by: publication date number of citations

• Hard color-singlet exchange in dijet events in proton-proton collisions at $\sqrt{s} = 13$ TeV

  Cristian Baldenegro Barrera

  SciPost Phys. Proc. 8, 015 (2022) · published 11 July 2022 | Toggle abstract · pdf

  We present a measurement of events with two jets separated by a pseudorapidity gap (jet-gap-jet). The signature is expected from hard color-singlet exchange. The jets are reconstructed with the CMS detector. The highest $p_\text{T}$ jets have $p_\text{T}^\text{jet1,2} > 40$ GeV, with $1.4 < |\eta^\text{jet1,2}| < 4.7$ and $\eta^\text{jet1} \eta^\text{jet2} < 0$. We measure the fraction of color-singlet exchange dijet events, $f_\text{CSE}$, and compare it to previous measurements and to predictions. We also study jet-gap-jet events where the colliding protons remain intact and are detected with the Roman pots of TOTEM. A larger fraction $f_\text{CSE}$ is found in the latter subsample.

• Temporal fluctuations of correlators in integrable and chaotic quantum systems

  Talía L. M. Lezama, Yevgeny Bar Lev, Lea F. Santos

  SciPost Phys. 15, 244 (2023) · published 18 December 2023 | Toggle abstract · pdf

  We provide bounds on temporal fluctuations around the infinite-time average of out-of-time-ordered and time-ordered correlators of many-body quantum systems without energy gap degeneracies. For physical initial states, our bounds predict the exponential decay of the temporal fluctuations as a function of the system size. We numerically verify this prediction for chaotic and interacting integrable spin-1/2 chains, which satisfy the assumption of our bounds. On the other hand, we show analytically and numerically that for the XX model, which is a noninteracting system with gap degeneracies, the temporal fluctuations decay polynomially with system size for operators that are local in the fermion representation and decrease exponentially in the system size for non-local operators. Our results demonstrate that the decay of the long-time temporal fluctuations of correlators cannot be used as a reliable metric of chaos or lack thereof.

• A quantum register using collective excitations in a Bose-Einstein condensate

  Elisha Haber, Zekai Chen, Nicholas P. Bigelow

  SciPost Phys. 15, 188 (2023) · published 8 November 2023 | Toggle abstract · pdf

  A qubit made up of an ensemble of atoms is attractive due to its resistance to atom losses. In this work, we consider an experimentally feasible protocol to coherently load a spin-dependent optical lattice from a spatially overlapping Bose-Einstein condensate. Identifying each lattice site as a qubit, with an empty or filled site as the qubit basis, we discuss how high-fidelity single-qubit operations, two-qubit gates between arbitrary pairs of qubits, and nondestructive measurements could be performed. In this setup, the effect of atom losses has been mitigated, the atoms never need to be removed from the ground state manifold, and separate storage and computational bases for the qubits are not required, all of which can be significant sources of decoherence in many other types of atomic qubits.

• 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.

• Calculation of asymptotic normalization coefficients in the complex-ranged Gaussian basis

  Dinmukhamed A. Sailaubek, Olga A. Rubtsova

  SciPost Phys. Proc. 3, 043 (2020) · published 27 February 2020 | Toggle abstract · pdf

  A new technique towards finding asymptotic normalization coefficients in the complex-ranged Gaussian basis is presented. It is shown that a diagonalisation procedure for the total Hamiltonian matrix in the given basis results in approximation for a radial part of the bound state wave function from the origin up to the far asymptotic distances, which allows to extract ANCs rather accurately. The method is illustrated by calculations of single-particle ANCs for nuclei bound states in cases of non-local nucleon-nucleus interactions, in particular, phenomenological global potentials with the Perey-Buck's non-locality.

• Reconstructing the potential configuration in a high-mobility semiconductor heterostructure with scanning gate microscopy

  Gaëtan J. Percebois, Antonio Lacerda-Santos, Boris Brun, Benoit Hackens, Xavier Waintal, Dietmar Weinmann

  SciPost Phys. 15, 242 (2023) · published 15 December 2023 | Toggle abstract · pdf

  The weak disorder potential seen by the electrons of a two-dimensional electron gas in high-mobility semiconductor heterostructures leads to fluctuations in the physical properties and can be an issue for nanodevices. In this paper, we show that a scanning gate microscopy (SGM) image contains information about the disorder potential, and that a machine learning approach based on SGM data can be used to determine the disorder. We reconstruct the electric potential of a sample from its experimental SGM data and validate the result through an estimate of its accuracy.

• Multiple Andreev reflections in diffusive SINIS and SIFIS junctions

  Artem V. Polkin, Pavel A. Ioselevich

  SciPost Phys. 15, 100 (2023) · published 18 September 2023 | Toggle abstract · pdf

  We study Multiple Andreev Reflections in long diffusive superconductor(S)-normal metal(N)-superconductor junctions with low-transparency interfaces. Assuming strong thermalization in the weak link, we calculate the current-voltage dependence $I(V)$. At intermediate temperatures, $\varepsilon_\mathrm{Th}\ll T\ll\Delta$, the current is dominated by noncoherent multiple Andreev reflections and is obtained analytically. The results are generalized to a ferromagnetic junction. We find that the exchange field produces a non-trivial splitting of the subharmonic gap structure. This effect relies on thermalization and vanishes in SFS junctions with no energy relaxation in the weak link.

• Study of light nuclei by polarization observables in electron scattering

  Simon Širca

  SciPost Phys. Proc. 3, 048 (2020) · published 27 February 2020 | Toggle abstract · pdf

  Electron-induced proton, neutron and deuteron knock-out remains the most versatile probe of the electro-magnetic properties and spin structure of light nuclei. The advent of highly polarized beams and targets and improvements in recoil polarization methods, as well as analysis and simulation techniques, have enabled us to study the static and dynamical properties of few-body systems with unprecedented precision. Recent experiments at Jefferson Lab and MAMI are presented and put into perspective of state-of-the art Faddeev calculations, with focus on the $^\mathbf{3}\mathbf{He}$ nucleus.

• Precision measurements of jet and photon production at the ATLAS experiment

  Giuseppe Callea

  SciPost Phys. Proc. 15, 016 (2024) · published 3 April 2024 | Toggle abstract · pdf

  The production of jets and prompt isolated photons at hadron colliders provides stringent tests of perturbative QCD. We present the latest measurements of photon+jets and diphoton production using proton-proton collision data collected by the ATLAS experiment at the LHC. The measurements are compared to state-of-the-art NLO and NNLO predictions.

• Measurements and searches of Higgs boson production involving fermion couplings with the ATLAS detector

  Shigeki Hirose

  SciPost Phys. Proc. 8, 006 (2022) · published 11 July 2022 | Toggle abstract · pdf

  In the standard model, fermions acquire the mass via the Yukawa interaction. This mechanism can be tested by measuring couplings of the fermions with the Higgs boson. At the ATLAS experiment, the Higgs-fermion coupling measurements became possible thanks to the abundant dataset: the integrated luminosity of 139~fb$^{-1}$ at the centre-of-mass energy of 13~TeV as well as 25~fb$^{-1}$ at 7--8~TeV. This paper presents recent results from measurements of the Higgs boson productions in decays to a fermion pair in the final state with the ATLAS detector.