Nuclear Theory·nucl-th

Thursday·August 20, 2020

7 papers—2 primary·5 cross-listed

03
[Submitted on 18 Aug 2020] (cross-list from hep-ph)
The role of the chiral anomaly in polarized deeply inelastic scattering I: Finding the triangle graph inside the box diagram in Bjorken and Regge asymptotics
Andrey Tarasov🇺🇸 · Raju Venugopalan🇺🇸
We revisit the role of the chiral "triangle" anomaly in deeply inelastic scattering (DIS) of electrons off polarized protons employing a powerful worldline formalism. We demonstrate how the triangle anomaly appears at high energies in the DIS box diagram for the polarized proton structure function $g_{1} (x_{B}, Q^{2})$ in both the Bjorken limit of large $Q^{2}$ and in the Regge limit of small $x_{B}$ . We show that the operator product expansion is not required to extract the anomaly in either asymptotics though it is sufficient in the Bjorken limit. Likewise, the infrared pole in the anomaly arises in both limits. The leading contribution to $g_{1}$ , in both Bjorken and Regge asymptotics, is therefore given by the expectation value of the topological charge density, generalizing a result previously argued by Jaffe and Manohar to hold for the first moment of $g_{1}$ . In follow-up work, we will show how our results motivate the derivation of a helicity-dependent effective action incorporating the physics of the anomaly at small $x_{B}$ and shall discuss the QCD evolution of $g_{1} (x_{B}, Q^{2})$ in this framework.
Comments:
28 pages, 4 figures; v2: Final version, to appear in PRD
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2008.08104 [pdf]
PRD(2020)·51 citations
04
[Submitted on 18 Aug 2020] (cross-list from hep-ph)
Beyond the MSW effect: Neutrinos in a dense medium
Antonio Capolupo🇮🇹 · Salvatore Marco Giampaolo🇭🇷 · Aniello Quaranta🇮🇹
We present a theory of neutrino oscillations in a dense medium which goes beyond the effective matter potential used in the description of the MSW effect. We show how the purity of the neutrino state is degraded by neutrino interactions with the environment and how neutrino--matter interactions can be a source of decoherence. We present new oscillation formulae for neutrinos interacting with leptons and carry out a numerical analysis which exhibits deviations from the MSW formulae for propagation through the Earth of ultra-high energy neutrinos. In particular, we show that at high density and/or high neutrino energy, the vanishing transition probabilities derived for MSW effect, are non zero when the scattering is taken into account.
Comments:
15 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2008.08119 [pdf]
PLB(2021)·26 citations
05
[Submitted on 19 Aug 2020] (cross-list from nucl-ex)
Strange Hadron Spectroscopy with Secondary KL Beam in Hall D
KLF Collaboration: Moskov Amaryan (ODU)🇺🇸 · Mikhail Bashkanov (UoY) · Sean Dobbs (FSU)🇺🇸 · James Ritman (Ruhr-U.)🇫🇷 · Justin Stevens (W&M)🇨🇦 · Igor Strakovsky (GWU)🇺🇸 · Shankar Adhikari (ODU)🇺🇸 · Arshak Asaturyan (YerPhi)🇺🇸 · Alexander Austregesilo (JLab)🇺🇸 · Marouen Baalouch (C.E.A.)🇺🇸 · Vitaly Baturin (ODU)🇺🇸 · Vladimir Berdnikov (CUA) and 140 other authors
We propose to create a secondary beam of neutral kaons in Hall D at Jefferson Lab to be used with the GlueX experimental setup for strange hadron spectroscopy. The superior CEBAF electron beam will enable a flux on the order of $1 \times 1 0^{4} K_{L} / sec$ , which exceeds the flux of that previously attained at SLAC by three orders of magnitude. The use of a deuteron target will provide first measurements ever with neutral kaons on neutrons. The experiment will measure both differential cross sections and self-analyzed polarizations of the produced $Λ$ , $Σ$ , $Ξ$ , and $Ω$ hyperons using the GlueX detector at the Jefferson Lab Hall D. The measurements will span CM $cos θ$ from $- 0.95$ to 0.95 in the range W = 1490 MeV to 2500 MeV. The new data will significantly constrain the partial wave analyses and reduce model-dependent uncertainties in the extraction of the properties and pole positions of the strange hyperon resonances, and establish the orbitally excited multiplets in the spectra of the $Ξ$ and $Ω$ hyperons. Comparison with the corresponding multiplets in the spectra of the charm and bottom hyperons will provide insight into he accuracy of QCD-based calculations over a large range of masses. The proposed facility will have a defining impact in the strange meson sector through measurements of the final state $K π$ system up to 2 GeV invariant mass. This will allow the determination of pole positions and widths of all relevant $K^{*} (K π)$ $S$ -, $P$ -, $D$ -, $F$ -, and $G$ -wave resonances, settle the question of the existence or nonexistence of scalar meson $κ / K_{0}^{*} (700)$ and improve the constrains on their pole parameters. Subsequently improving our knowledge of the low-lying scalar nonet in general.
Comments:
Final version of the KLF Proposal [C12-19-001] approved by JLab PAC48. The intermediate version of the proposal was posted in arXiv:1707.05284 [hep-ex]. 103 pages, 52 figures, 8 tables, 324 references. Several typos were fixed
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2008.08215 [pdf]
72 citations
06
[Submitted on 19 Aug 2020] (cross-list from hep-ph)
Hard-core deconfinement and soft-surface delocalization from nuclear to quark matter
Kenji Fukushima🇯🇵 · Toru Kojo🇨🇳 · Wolfram Weise🇩🇪
We propose a conceptual distinction between hard and soft realizations of deconfinement from nuclear to quark matter. In the high density region of Hard Deconfinement the repulsive hard cores of baryons overlap each other and bulk thermodynamics is dominated by the core properties that can be experimentally accessed in high-energy scattering experiments. We find that the equation of state estimated from a single baryon core is fairly consistent with those empirically known from neutron star phenomenology. We next discuss a novel concept of Soft Deconfinement, characterized by quantum percolation of quark wave-functions, at densities lower than the threshold for Hard Deconfinement. We make a brief review of quantum percolation in the context of nuclear and quark matter and illustrate a possible scenario of quark deconfinement at high baryon densities.
Comments:
14 pages, 12 figures; v2 published in PRD
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2008.08436 [pdf]
PRD(2020)·90 citations
07
[Submitted on 13 Jul 2020] (cross-list from hep-ex)
On Multifractal Spectra and Renyi Dimensions in 14.5A GeV/c $^{28}$ Si-nucleus Collisions
N. Ahmad🇮🇳 · A. Kamal🇸🇦 · M. M. Khan🇮🇳 · Hushnud🇮🇳 · A. Tufail🇮🇳
A systematic analysis of the data on 14.5A GeV/c $^{28}$ Si-nucleus collisions is carried out to investigate the behaviours of Renyi dimensions, Dq and Multifractal Spectral Function, $f (α_{q})$ . The Renyi dimensions, $D_{q}$ , are observed to decrease with increasing order of the moments, $q$ . However, the Multifractal Spectra are concave downwards with their maxima occurring around $α_{q} = 1.21 \pm 0.01$ . A continuous curve representing Multifractal Spectral Function, $f (α_{q})$ , characterizes manifestation of fluctuations in the rapidity space.
Comments:
Published
Subjects:
High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2008.08488 [pdf]
J.Mod.Phys.(2014)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE

The role of the chiral anomaly in polarized deeply inelastic scattering I: Finding the triangle graph inside the box diagram in Bjorken and Regge asymptotics

Beyond the MSW effect: Neutrinos in a dense medium

Strange Hadron Spectroscopy with Secondary KL Beam in Hall D

Hard-core deconfinement and soft-surface delocalization from nuclear to quark matter

On Multifractal Spectra and Renyi Dimensions in 14.5A GeV/c 28Si-nucleus Collisions

Affiliations

On Multifractal Spectra and Renyi Dimensions in 14.5A GeV/c $^{28}$ Si-nucleus Collisions