Nuclear Theory·nucl-th

Monday·February 20, 2023

6 papers—2 primary·4 cross-listed

03
[Submitted on 16 Feb 2023] (cross-list from hep-ph)
Neutrino Structure Functions from GeV to EeV Energies
Alessandro Candido🇮🇹 · Alfonso Garcia🇺🇸 · Giacomo Magni🇳🇱 · Tanjona Rabemananjara🇳🇱 · Juan Rojo🇳🇱 · Roy Stegeman🇬🇧
The interpretation of present and future neutrino experiments requires accurate theoretical predictions for neutrino-nucleus scattering rates. Neutrino structure functions can be reliably evaluated in the deep-inelastic scattering regime within the perturbative QCD (pQCD) framework. At low momentum transfers ( $Q^{2} \leq few$ GeV $^{2}$ ), inelastic structure functions are however affected by large uncertainties which distort event rate predictions for neutrino energies $E_{ν}$ up to the TeV scale. Here we present a determination of neutrino inelastic structure functions valid for the complete range of energies relevant for phenomenology, from the GeV region entering oscillation analyses to the multi-EeV region accessible at neutrino telescopes. Our NNSF $ν$ approach combines a machine-learning parametrisation of experimental data with pQCD calculations based on state-of-the-art analyses of proton and nuclear parton distributions (PDFs). We compare our determination to other calculations, in particular to the popular Bodek-Yang model. We provide updated predictions for inclusive cross sections for a range of energies and target nuclei, including those relevant for LHC far-forward neutrino experiments such as FASER $ν$ , SND@LHC, and the Forward Physics Facility. The NNSF $ν$ determination is made available as fast interpolation LHAPDF grids, and can be accessed both through an independent driver code and directly interfaced to neutrino event generators such as GENIE.
Comments:
62 pages, 34 figures. The NNSF $ν$ structure function grids and code can be obtained from https://nnpdf.github.io/nnusf/. A few more typos corrected and new references added
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2302.08527 [pdf]
JHEP(2023)·58 citations
04
[Submitted on 16 Feb 2023] (cross-list from hep-th)
A Fully Solvable Model of Fermionic Interaction in $3 + 1 d$
Seth Grable🇺🇸 · Max Weiner🇺🇸
Recently, Romatschke found that the poles in $O (N)$ scalar theories do not affect observables such as temperature and pressure. Romatschke went on to show this result holds for marginal, relevant, and irrelevant operators in $3 + 1 d$ $(O (N)$ scalar theories. We continue in this direction by studying large- $N$ fermi-interactions in $3 + 1 d$ . To do so, we produce a model of marginally coupled fermi-interactions which is fully renormalizable at large- $N$ . This theory contains poles in the running coupling, however we argue these poles do not affect any physical observables. Further, our theory contains first order phase transition which separates a stable, meta-stable, and unstable phase.
Subjects:
High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2302.08603 [pdf]
JHEP(2023)·12 citations
05
[Submitted on 17 Feb 2023] (cross-list from hep-ph)
Two body final states production in electron-positron annihilation and their contributions to $(g - 2)_{μ}$
Shi-Jia Wang🇨🇳 · Zhen Fang🇨🇳 · Ling-Yun Dai🇨🇳
In this paper, we study the processes of $e^{+} e^{-}$ annihilation into two body final states, either two pseudoscalar mesons or one meson with a photon. The hadronic vacuum polarization form factors are calculated within the framework of resonance chiral theory in the energy region of $E ≲ 2$ GeV, with final state interactions taken into account. A joint analysis on the processes of $e^{+} e^{-} \to π^{+} π^{-}$ , $K^{+} K^{-}$ , $K_{L}^{0} K_{S}^{0}$ , $π^{0} γ$ , and $η γ$ has been performed, and the latest experimental data are included. Based on the vacuum polarization form factors of these processes, we estimate their contributions to the lowest order of anomalous magnetic moment of the muon, $(g - 2)_{μ}$ . Combined with other contributions from hadronic vacuum polarization and other interactions from the standard model, the discrepancy between theoretical prediction and experimental measurement is $Δ a_{μ} = (24.1 \pm 5.4) \times 1 0^{- 10}$ , i.e., 4.5 $σ$ .
Comments:
45 pages, 6 figures, to be the same as the published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2302.08859 [pdf]
JHEP(2023)·20 citations
06
[Submitted on 17 Feb 2023] (cross-list from physics.comp-ph)
Multi-body wave function of ground and low-lying excited states using unornamented deep neural networks
Tomoya Naito · Hisashi Naito · Koji Hashimoto
We propose a method to calculate wave functions and energies not only of the ground state but also of low-lying excited states using a deep neural network and the unsupervised machine learning technique. For systems composed of identical particles, a simple method to perform symmetrization for bosonic systems and antisymmetrization for fermionic systems is also proposed.
Comments:
23 pages, 18 figures, 8 tables; Typo of Eq. (25) corrected
Subjects:
Computational Physics (physics.comp-ph); cond-mat.other (cond-mat.other); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2302.08965 [pdf]
PRResearch(2023)·8 citations

Affiliations

first authorsco-authorsvia INSPIRE

Neutrino Structure Functions from GeV to EeV Energies

A Fully Solvable Model of Fermionic Interaction in 3+1d

Two body final states production in electron-positron annihilation and their contributions to (g−2)μ​

Multi-body wave function of ground and low-lying excited states using unornamented deep neural networks

Affiliations

A Fully Solvable Model of Fermionic Interaction in $3 + 1 d$

Two body final states production in electron-positron annihilation and their contributions to $(g - 2)_{μ}$