Publications

Order by: publication date number of citations

• PineAPPL: NLO EW corrections for PDF processes

  Christopher Schwan

  SciPost Phys. Proc. 8, 079 (2022) · published 12 July 2022 | Toggle abstract · pdf

  Modern parton distribution function (PDF) determinations either neglect higher-order corrections in the electroweak (EW) coupling or implement them approximately for a subset of PDF processes. We present a new tool, PineAPPL, which supports perturbative correction in arbitrary powers of the EW and strong coupling constant, and stores theoretical predictions independently of the used PDFs in so-called interpolation grids. These are the foundation of any PDF determination, and will allow us to perform a PDF fit taking into account EW corrections for all processes consistently. Apart from PDF determinations PineAPPL can also be used in precision phenomenology to study the impact of different choices of PDF sets, without rerunning the time-consuming computation. As an application of this tool we show Drell-Yan (DY) lepton-pair production were larger effects of NLO EW corrections can be seen that will potentially influence the PDF fit and comment about which observables are particularly suited and NLO EW PDF fit and which are not.

  1 citation

• Structure Functions and Parton Densities: a Session Summary

  Benjamin Nachman, Katarzyna Wichmann, Pia Zurita

  SciPost Phys. Proc. 8, 004 (2022) · published 11 July 2022 | Toggle abstract · pdf

  Studies of fragmentation and parton density functions are a core component of researchin high energy particle and nuclear physics. These quantities are inherently interestingas a probe of the quantum nature of the strong force and are also essential ingredients toadditional studies in high energy scattering experiments. These proceedings provide anoverview of the state of the art in this area, as presented at the Deep-Inelastic ScatteringConference in the Spring of 2021.

  1 citation

• Multidimensional, high precision beam spin asymmetry measurements of semi-inclusive pion production off the proton with CLAS12

  S. Diehl

  SciPost Phys. Proc. 8, 149 (2022) · published 14 July 2022 | Toggle abstract · pdf

  High precision measurements of the polarized electron beam-spin asymmetry in SIDIS from the proton have been performed using a 10.6 GeV incident electron beam and the CLAS12 spectrometer at Jefferson Lab. The proceeding reports a multidimensional study of the structure function ratio $F^{sin\phi}_{LU}/F_{UU}$ extracted from single pion ($\pi^{+}$, $\pi^{-}$, $\pi^{0}$) SIDIS data over a large kinematic range in $z$, $x_{B}$, $P_{T}$ and virtualities $Q^{2}$ ranging from 1~GeV$^2$ up to 7~GeV$^2$. $F^{sin\phi}_{LU}$ is a twist-3 quantity that can reveal novel properties of quark-gluon correlations within the nucleon.

  1 citation

• Differential measurements of jet sub-structure observables and their correlation in p+p collisions at √s = 200 GeV in STAR

  Monika Robotková

  SciPost Phys. Proc. 8, 071 (2022) · published 12 July 2022 | Toggle abstract · pdf

  This analysis extends recent measurements of the jet sub-structure observables based on the SoftDrop algorithm in p+p collisions at √s = 200 GeV in the STAR experiment. We present fully unfolded multi-differential measurements of jet sub-structure observables at the first split and their correlations for jets of different transverse momenta and radii. We compare our measurements to various Monte Carlo models.

  1 citation

• Production of three isolated photons in the high-energy factorization approach

  Vladimir Saleev

  SciPost Phys. Proc. 8, 167 (2022) · published 14 July 2022 | Toggle abstract · pdf

  We study large-$p_T$ three-photon production at the LHC at the center-of-mass energy $\sqrt{s}=8$ TeV. We use the LO approximation of the parton Reggeization approach consistently merged with the real NLO corrections. For numerical calculations use the parton-level generator KaTie and modified KMR-type unintegrated parton distribution functions. We find good agreement between our predictions and data with the same accuracy as in the NNLO calculations based on the collinear parton model of QCD. At higher energies ($\sqrt{s}=13$ and 27 TeV) parton Reggeization approach predicts larger cross sections, up to $\sim 10$ \% and $\sim 20$ \%, respectively.

  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

• Top-quark mass determination in the optimised threshold scan

  Kacper Nowak, Aleksander Filip Zarnecki

  SciPost Phys. Proc. 8, 173 (2022) · published 14 July 2022 | Toggle abstract · pdf

  One of the important goals at the future e$^+$e$^−$ colliders is to measure the top-quark mass and width in a scan of the pair production threshold. Presented in this work is the most general approach to the top-quark mass determination from the threshold scan at CLIC, with all relevant model parameters and selected systematic uncertainties included in the fit procedure. In the baseline scan scenario the top-quark mass can be extracted with precision of the order of 30 to 40 MeV, already for 100 fb$^{−1}$ of data collected at the threshold. We present the optimisation procedure based on the genetic algorithm with which the statistical uncertainty of the mass measurement can be reduced by about 20%.

  1 citation

• Accessing quark GPDs in diffractive events at an electron-ion collider

  W. Cosyn, B. Pire, L. Szymanowski

  SciPost Phys. Proc. 8, 159 (2022) · published 14 July 2022 | Toggle abstract · pdf

  We discuss two collider processes which combine a diffractively produced $\rho$ meson separated by a large rapidity gap from a hard exclusive scattering of a Pomeron on a nucleon, giving rise to a lepton pair or to a second meson. These two processes probe the nucleon quark content described by generalized parton distributions in a very specific way.

  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

• Transverse Single-Spin Asymmetries of Midrapidity Direct Photons and Neutral Mesons at PHENIX

  Nicole Lewis

  SciPost Phys. Proc. 8, 009 (2022) · published 11 July 2022 | Toggle abstract · pdf

  Results are presented for the transverse single-spin asymmetries of direct photons, neutral pions, and eta mesons for $|\eta|<0.35$ from $p^\uparrow + p$ collisions with $\sqrt{s} = 200$ GeV at PHENIX. As hadrons, $\pi^0$ and $\eta$ mesons are sensitive to both initial- and final-state effects and at midrapidity probe the dynamics of gluons along with a mix of quark flavors. Because direct photon production does not include hadronization, the direct photon TSSA is only sensitive to initial-state effects and at midrapidity provides a clean probe of the gluon dynamics in transversely polarized protons. All three of these results will help constrain the collinear twist-3 trigluon correlation function as well as the gluon Sivers function, improving our knowledge of spin-dependent gluon dynamics in QCD.