Nuclear Theory·nucl-th

Thursday·January 30, 2020

10 papers—5 primary·5 cross-listed

06
[Submitted on 18 Dec 2019] (cross-list from physics.hist-ph)
Tony Skyrme and the Origins of Skyrmions
Ian J. R. Aitchison (SLAC National Accelerator Laboratory and Oxford University)🇺🇸
I first discuss the main motivations for Tony Skyrme's highly original program (1958-62) of making fermionic nucleons out of bosonic pion fields, as described in his Cosener's House talk in 1984. These include a dislike of point-like elementary particles, which he blamed for infinite renormalization, and a preference for extended objects distinguished by what we would now call topological quantum numbers. In this he was strongly influenced by William Thomson (Lord Kelvin), who was so impressed by Helmholtz's proof of the conservation of circulation ("Wirbelbewegung") in fluid vortices that he developed an entire theory of atoms as knotted vortices in the ether fluid. Skyrme liked mechanical models, as did Kelvin, and he grew up fascinated by the ingenuity of Kelvin's machine for predicting tides, an example of which stood in his grandfather's house. This seems to have been connected to his strong preference for bosonic fields, which have a classical limit, over fermionic fields which do not. I then sketch the progress of Skyrme's ideas in the series of six papers in the years 1958-62, which passed largely unnoticed at the time. I emphasize his remarkable intuition that the kink solution of the classical Sine-Gordon equation would be a fermion when quantized, and the novelty of his identification of the Skyrmion winding number with baryon number in the three-dimensional case. I end by briefly describing how Skyrme's work was dramatically related to QCD in 1983-4.
Comments:
Invited talk at "The First British-German Wilhelm and Else Heraeus Seminar" on Skyrmions in Magnetic Materials, Bad Honnef, Dec. 1-5, 2019
Subjects:
History and Philosophy of Physics (physics.hist-ph); cond-mat.other (cond-mat.other); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2001.09944 [pdf]
3 citations
07
[Submitted on 28 Jan 2020] (cross-list from hep-ph)
Low energy doubly-virtual Compton scattering from di-lepton electroproduction on a nucleon
Vladyslav Pauk🇩🇪 · Carl E. Carlson🇺🇸 · Marc Vanderhaeghen🇩🇪
We propose a new way to experimentally determine the subleading low-energy structure constant of doubly-virtual Compton scattering on a proton. Such empirical determination will reduce the theoretical model error in estimates of the hadronic correction to the muonic hydrogen Lamb shift. We demonstrate that the di-lepton forward-backward asymmetry in the $e^{-} p \to e^{-} p e^{-} e^{+}$ process, which can be accessed at electron scattering facilities, yields a large sensitivity to this so far unknown low-energy constant.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2001.10626 [pdf]
PRC(2020)·8 citations
08
[Submitted on 29 Jan 2020] (cross-list from astro-ph.HE)
The impact of isomers on a kilonova associated with neutron star mergers
Shin-ichiro Fujimoto · Masa-aki Hashimoto
We investigate the significance of isomers on a kilonova associated with neutron star mergers (NSMs) for the first time. We calculate the evolution of abundances and energy generation rates ( $ϵ ˙_{nuc}$ ) of ejecta from NSMs, taking into account $β^{-}$ decay through isomers. We find that for ejecta with electron fraction ( $Y_{e}$ ) of $0.2 - 0.3$ , $ϵ ˙_{nuc}$ is appreciably changed from those without isomers, due to the large change in timing of $β^{-}$ decay through the isomeric states of $^{123, 125, 127} Sn$ and $^{128} Sb$ . In particular, the effects of the isomers on $ϵ ˙_{nuc}$ are prominent for ejecta of $Y_{e} \sim 0.25$ , which could emit a fraction of an early, blue component of a kilonova observed in GW170817. When the excitation from a ground state to its isomeric state is important, the isomers of $^{129} Sb$ and $^{129, 131} Te$ also cause additional and appreciable change in $ϵ ˙_{nuc}$ . Furthermore, we demonstrate that larger amounts of lanthanide-free ejecta result in a better fit of an observed light curve of the kilonova in GW170817 if the isomers are taken into account.
Comments:
6 pages, 4 figures. Accepted for publication in MNRAS
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2001.10668 [pdf]
MNRAS(2020)·24 citations
09
[Submitted on 29 Jan 2020] (cross-list from hep-ph)
Review of proton and nuclear shape fluctuations at high energy
Heikki Mäntysaari🇫🇮
Determining the inner structure of protons and nuclei in terms of their fundamental constituents has been one of the main tasks of high energy nuclear and particle physics experiments. This quest started as a mapping of the (average) parton densities as a function of longitudinal momentum fraction and resolution scale. Recently, the field has progressed to more differential imaging, where one important development is the description of the event-by-event quantum fluctuations in the wave function of the colliding hadron. In this Review, recent developments on the extraction of proton and nuclear transverse geometry with event-by-event fluctuations from collider experiments at high energy is presented. The importance of this fundamentally interesting physics in other collider experiments like in studies of the properties of the Quark Gluon Plasma is also illustrated.
Comments:
19 pages, 13 figures. Invited review published in Reports on Progress in Physics. v2: matches published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2001.10705 [pdf]
Rept.Prog.Phys.(2020)·103 citations
10
[Submitted on 29 Jan 2020] (cross-list from hep-ph)
Confronting Experimental Data with Heavy-Ion Models: Rivet for Heavy Ions
Christian Bierlich🇩🇰 · Andy Buckley🇬🇧 · Christian Holm Christensen🇩🇰 · Peter Harald Lindenov Christiansen🇸🇪 · Cody B. Duncan🇩🇪 · Jan Fiete Grosse-Oetringhaus🇨🇭 · Przemyslaw Karczmarczyk🇵🇱 · Patrick Kirchgaeßer🇩🇪 · Jochen Klein🇮🇹 · Leif Lönnblad🇸🇪 · Roberto Preghenella🇮🇹 · Christine O. Rasmussen🇸🇪 · Maria Stefaniak🇫🇷 · Vytautas Vislavicus🇩🇰
The Rivet library is an important toolkit in particle physics, and serves as a repository for analysis data and code. It allows for comparisons between data and theoretical calculations of the final state of collision events. This paper outlines several recent additions and improvements to the framework to include support for analysis of heavy ion collision simulated data. The paper also presents examples of these recent developments and their applicability in implementing concrete physics analyses.
Comments:
31 pages, 12 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2001.10737 [pdf]
EPJC(2020)·25 citations

Affiliations

first authorsco-authorsvia INSPIRE

Tony Skyrme and the Origins of Skyrmions

Low energy doubly-virtual Compton scattering from di-lepton electroproduction on a nucleon

The impact of isomers on a kilonova associated with neutron star mergers

Review of proton and nuclear shape fluctuations at high energy

Confronting Experimental Data with Heavy-Ion Models: Rivet for Heavy Ions

Affiliations