PaperPanorama

Nuclear Theory·nucl-th

Friday·April 29, 2022

4 papers1 primary·3 cross-listed

  1. 02

    Compatibility of Neutrino DIS Data and Its Impact on Nuclear Parton Distribution Functions

    K.F.Muzakka🇩🇪 · P.Duwentäster🇩🇪 · T.J.Hobbs🇺🇸 · T.Ježo🇩🇪 · M.Klasen🇩🇪 · K.Kovařík🇩🇪 · A.Kusina🇵🇱 · J.G.Morfín🇺🇸 · F.I.Olness🇺🇸 · R.Ruiz🇵🇱 · I.Schienbein🇫🇷 · J.Y.Yu🇺🇸

    In global analyses of nuclear parton distribution functions (nPDFs), neutrino deep-inelastic scattering (DIS) data have been argued to exhibit tensions with the data from charged-lepton DIS. Using the nCTEQ framework, we investigate these possible tensions both internally and with the data sets used in our recent nPDF analysis nCTEQ15WZSIH. We take into account nuclear effects in the calculation of the deuteron structure function using the CJ15 analysis. The resulting nPDF fit, nCTEQ15WZSIHdeut, serves as the basis for our comparison with inclusive neutrino DIS and charm dimuon production data. Using hypothesis testing, we confirm evidence of tensions with these data and study the impact of the proton PDF baseline as well as the treatment of data correlation and normalization uncertainties. We identify the experimental data and kinematic regions that generate the tensions and present several possible approaches how a consistent global analysis with neutrino data can be performed. We show that the tension can be relieved using a kinematic cut at low () and also investigate a possibility of managing the tensions by using uncorrelated systematic errors. Finally, we present a different approach identifying a subset of neutrino data which leads to a consistent global analysis without any additional cuts. Understanding these tensions between the neutrino and charged-lepton DIS data is important not only for a better flavor separation in global analyses of nuclear and proton PDFs, but also for neutrino physics and for searches for physics beyond the Standard Model.

    hep-phhep-exnucl-thPRD(2022)·41 citations
  2. 03

    Mathematical formulae for neutron self-shielding properties of media in an isotropic neutron field

    Ateia W. Mahmoud🇪🇬 · Elsayed K. Elmaghraby🇪🇬 · E. Salama🇪🇬 · A. Elghazaly🇪🇬 · S. A. El-fiki🇪🇬

    The complexity of the neutron transport phenomenon throws its shadows on every physical system wherever neutron is produced or used. In the current study, an ab initio derivation of the neutron self-shielding factor to solve the problem of the decrease of the neutron flux as it penetrates into a material placed in an isotropic neutron field. We have employed the theory of steady-state neutron transport, starting from Stuart's formula. Simple formulae were derived based on the integral cross-section parameters that could be adopted by the user according to various variables, such as the neutron flux distribution and geometry of the simulation at hand. The concluded formulae of the self-shielding factors comprise an inverted sigmoid function normalized with a weight representing the ratio between the macroscopic total and scattering cross-sections of the medium. The general convex volume geometries are reduced to a set of chord lengths, while the neutron interactions probabilities within the volume are parameterized to the epithermal and thermal neutron energies. The arguments of the inverted-sigmoid function were derived from a simplified version of neutron transport formulation. Accordingly, the obtained general formulae were successful in giving the values of the experimental neutron self-shielding factor for different elements and different geometries.

    physics.comp-phhep-phnucl-thPhys.Scripta(2024)·1 citation
  3. 04

    First concurrent extraction of the leading-order scalar and spin proton polarizabilities

    E. Mornacchi (1)🇩🇪 · S. Rodini (2)🇩🇪 · B. Pasquini (3 and 4)🇮🇹 · P. Pedroni (4) ((1) Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, Mainz, Germany, (2) Institut für Theoretische Physik, Universität Regensburg, Regensburg, Germany, (3) Dipartimento di Fisica, Università degli Studi di Pavia, Pavia, Italy, (4) INFN Sezione di Pavia, Pavia, Italy)🇮🇹

    We performed the first simultaneous extraction of the six leading-order proton polarizabilities. We reached this milestone thanks to both new high-quality experimental data and an innovative bootstrap-base fitting method. These new results provide a self-consistent and fundamental benchmark for all future theoretical and experimental polarizability estimates.

    hep-phnucl-exnucl-thPRL(2022)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE