Publications

Order by: publication date number of citations

• In-plane Fermi surface mapping of ZrSiS and HfSiS by de Haas-van Alphen oscillations

  Bruno Gudac, Mihovil Bosnar, Filip Orbanić, Trpimir Ivšić, Ivan Kokanović, Mario Novak

  SciPost Phys. Proc. 11, 019 (2023) · published 6 June 2023 | Toggle abstract · pdf

  We have conducted a comprehensive experimental investigation of the in-plane de Haas van Alphen quantum oscillations in ZrSiS and HfSiS and compared the results to the ab-initio calculations. We found a moderately good agreement for a set of frequencies located between 100 T and 200 T. These could be associated with extremal orbitals of the electron pockets located around the $k_z=\pm\pi/2c$ planes at the edge of the 1st Brillouin zone. In contrast, the experimentally detected low-frequency set of oscillations found around 20 T could not be reproduced by the calculations. Further refinement of the ab-initio calculation has to be conducted to fully capture all the observed features of the Fermi surface in ZrSiS and HfSiS.

  1 citation

• Single-Logarithmic Corrections to Small-$x$ Helicity Evolution

  Yossathorn Tawabutr

  SciPost Phys. Proc. 8, 103 (2022) · published 13 July 2022 | Toggle abstract · pdf

  The small-$x$ quark helicity evolution equations at double-logarithmic order, with the kernel $\sim\alpha_s\ln^2(1/x)$, have been derived previously. In this work, we derive the single-logarithmic corrections to the equations, to order $\alpha_s\ln(1/x)$ of the evolution kernel. The new equations include the effects of the running coupling and the unpolarized small-$x$ evolution, both of which are parametrically significant at single-logarithmic order. The large-$N_c$ and large-$N_c\& N_f$ approximations to the equation are computed. (Here, $N_c$ and $N_f$ are the numbers of quark colors and flavors, respectively.) Their solutions will provide more precise estimates of the quark helicity distribution at small $x$, contributing to the resolution of the proton spin puzzle.

  1 citation

• Masses of vector and pseudovector hybrid mesons in a chiral symmetric model

  Walaa I. Eshraim

  SciPost Phys. Proc. 6, 014 (2022) · published 31 May 2022 | Toggle abstract · pdf

  We enlarge the chiral model, the so-called extended Linear Sigma Model (eLSM), by including the low-lying hybrid nonet with exotic quantum numbers $J^{PC}=1^{-+}$ and the nonet of their chiral partners with $J^{PC}=1^{+-}$ to a global $U(3)_r \times U(3)_l$ chiral symmetry. We use the assignment of the $\pi_1^{hyb}= \pi_1(1600)$ as input to determine the unknown parameters. Then, we compute the lightest vector and pseudovector hybrid masses that could guide ongoing and upcoming experiments in searching for hybrids.

  1 citation

• Search for low mass WIMP dark matter with DarkSide-50

  Masato Kimura on behalf of DarkSide-50 Collaboration

  SciPost Phys. Proc. 12, 022 (2023) · published 3 July 2023 | Toggle abstract · pdf

  DarkSide-50 is a direct dark matter detection experiment at Laboratori Nazionali del Gran Sasso that uses argon as the target material. Exploiting the ionization signal from a dual-phase time projection chamber filled with low-radioactivity argon, it has set the most stringent exclusion limit on WIMPs with a mass of few $\mathrm{GeV}/c^2$. A new analysis has recently been carried out with a larger exposure, profiting from an improved understanding of the detector response and background model. An improvement of about a factor 10 in sensitivity is expected for a WIMP mass of 2 GeV/c$^2$.

  1 citation

• Time reversal-odd effects in QCD and beyond

  Dylan Manna, Andrea Signori, Christine Aidala

  SciPost Phys. Proc. 8, 169 (2022) · published 14 July 2022 | Toggle abstract · pdf

  In this paper we will describe a parallel between phenomenological and symmetry-based descriptions of the process dependence of the time-reversal-odd phenomena in QCD, such as the Sivers effect, with the goal of defining the essential elements that lead to such process dependence in QCD. This will then serve as a starting point to explore possible generalizations in a different gauge theory.

  1 citation

• Excitation transfer in disordered spin chains with long-range exchange interactions

  Nikolaos E. Palaiodimopoulos, Maximilian Kiefer-Emmanouilidis, Gershon Kurizki, David Petrosyan

  SciPost Phys. Core 6, 017 (2023) · published 22 March 2023 | Toggle abstract · pdf

  We examine spin excitation or polarization transfer via spin chains with long-range exchange interactions in the presence of diagonal and off-diagonal disorder. To this end, we determine the mean localization length of the single-excitation eigenstates of the chain for various strengths of the disorder. We then identify the energy eigenstates of the system with large localization length and sufficient support at the chain boundaries that are suitable to transfer an excitation between the sender and receiver spins connected to the opposite ends of the chain. We quantify the performance of two transfer schemes involving weak static couplings of the sender and receiver spins to the chain, and time-dependent couplings realizing stimulated adiabatic passage of the excitation via the intermediate eigenstates of the chain which exhibits improved performance.

  1 citation

• Connected and Disconnected Sea Partons from CT18 Parametrization of PDFs

  Tie-Jiun Hou, Jian Liang, Keh-Fei Liu, Mengshi Yan, C.-P. Yuan

  SciPost Phys. Proc. 8, 067 (2022) · published 12 July 2022 | Toggle abstract · pdf

  The separation of the connected and disconnected sea partons, which were uncovered in the Euclidean path-integral formulation of the hadronic tensor, is accommodated with the CT18 parametrization of the global analysis of the parton distribution functions (PDFs). This is achieved with the help of the distinct small $x$ behaviors of these two sea parton components and the constraint from the lattice calculation of the ratio of the strange momentum fraction to that of the ${\bar u}$ or ${\bar d}$ in the disconnected insertion. This allows lattice calculations of separate flavors in both the connected and disconnected insertions to be directly compared with the global analysis results term by term.

  1 citation

• New machine learning techniques for simulation-based inference: InferoStatic nets, kernel score estimation, and kernel likelihood ratio estimation

  Kyoungchul Kong, Konstantin T. Matchev, Stephen Mrenna, Prasanth Shyamsundar

  SciPost Phys. Codebases 14 (2023) · published 7 July 2023 | Toggle abstract · pdf

  We propose an intuitive, machine-learning approach to multiparameter inference, dubbed the InferoStatic Networks (ISN) method, to model the score and likelihood ratio estimators in cases when the probability density can be sampled but not computed directly. The ISN uses a backend neural network that models a scalar function called the inferostatic potential $\varphi$. In addition, we introduce new strategies, respectively called Kernel Score Estimation (KSE) and Kernel Likelihood Ratio Estimation (KLRE), to learn the score and the likelihood ratio functions from simulated data. We illustrate the new techniques with some toy examples and compare to existing approaches in the literature. We mention en passant some new loss functions that optimally incorporate latent information from simulations into the training procedure.

  1 citation

• Can we make sense out of "Tensor Field Theory"?

  Vincent Rivasseau, Fabien Vignes-Tourneret

  SciPost Phys. Core 4, 029 (2021) · published 11 November 2021 | Toggle abstract · pdf

  We continue the constructive program about tensor field theory through the next natural model, namely the rank five tensor theory with quartic melonic interactions and propagator inverse of the Laplacian on $U(1)^5$. We make a first step towards its construction by establishing its power counting, identifying the divergent graphs and performing a careful study of (a slight modification of) its RG flow. Thus we give strong evidence that this just renormalizable tensor field theory is non perturbatively asymptotically free.

  1 citation

• Impact of LHC dijet production in pp and pPb collisions on the nNNPDF2.0 nuclear PDFs

  Rabah Abdul Khalek

  SciPost Phys. Proc. 8, 135 (2022) · published 14 July 2022 | Toggle abstract · pdf

  We quantify the impact of LHC dijet production measurements on the nNNPDF2.0 nuclear PDFs in twofold. First, from a proton baseline based on NNPDF3.1 and augmented by pp dijet production measurements from ATLAS and CMS at 7 and 8 TeV. Second, from a new nNNPDF2.0 global analysis including the ratio of pPb to pp dijet spectra from CMS at 5 TeV. We show that as opposed to the CMS at 5 TeV absolute pp and pPb dijet spectra, the pPb/pp ratio is well described in a nPDFs fit and provides strong constraints on the gluon of lead.

  1 citation