Nuclear Theory·nucl-th

Monday·February 17, 2020

10 papers—6 primary·4 cross-listed

07
A New Heavy Flavor Program for the Future Electron-Ion Collider
Xuan Li🇺🇸 · Ivan Vitev🇺🇸 · Melynda Brooks🇺🇸 · Lukasz Cincio🇺🇸 · J. Matthew Durham🇺🇸 · Michael Graesser🇺🇸 · Ming X. Liu🇺🇸 · Astrid Morreale🇺🇸 · Duff Neill🇺🇸 · Cesar da Silva🇺🇸 · Walter E. Sondheim🇺🇸 · Boram Yoon🇺🇸
The proposed high-energy and high-luminosity Electron-Ion Collider (EIC) will provide one of the cleanest environments to precisely determine the nuclear parton distribution functions (nPDFs) in a wide $x$ - $Q^{2}$ range. Heavy flavor production at the EIC provides access to nPDFs in the poorly constrained high Bjorken- $x$ region, allows us to study the quark and gluon fragmentation processes, and constrains parton energy loss in cold nuclear matter. Scientists at the Los Alamos National Laboratory are developing a new physics program to study heavy flavor production, flavor tagged jets, and heavy flavor hadron-jet correlations in the nucleon/nucleus going direction at the future EIC. The proposed measurements will provide a unique way to explore the flavor dependent fragmentation functions and energy loss in a heavy nucleus. They will constrain the initial-state effects that are critical for the interpretation of previous and ongoing heavy ion measurements at the Relativistic Heavy Ion Collider and the Large Hadron Collider. We show an initial conceptual design of the proposed Forward Silicon Tracking (FST) detector at the EIC, which is essential to carry out the heavy flavor measurements. We further present initial feasibility studies/simulations of heavy flavor hadron reconstruction using the proposed FST.
↳ nucl-exhep-exhep-phnucl-thEPJ Web Conf.(2020)·23 citations
08
Transport properties in magnetized compact stars
Toshitaka Tatsumi🇯🇵 · Hiroaki Abuki🇯🇵
Transport properties of dense QCD matter is discussed. Using the Kubo formula for conductivity, we discuss some topological aspects of quark matter during chiral transition. The close relation to Weyl semimetal is pointed out and anomalous Hall effect is demonstrated to be possible there. In particular, it is shown that the spectral asymmetry of the quasi-particles plays an important role for the Hall conductivity in the magnetic field.
↳ hep-phnucl-thSymmetry(2020)·1 citation
09
The Hoyle Family: The search for alpha-condensate states in light nuclei
R. Smith · J. Bishop · J. Hirst · Tz. Kokalova · C. Wheldon
Our present understanding of the structure of the Hoyle state in $^{12}$ C and other near-threshold states in $α$ -conjugate nuclei is reviewed in the framework of the $α$ -condensate model. The $^{12}$ C Hoyle state, in particular, is a candidate for $α$ -condensation, due to its large radius and $α$ -cluster structure. The predicted features of nuclear $α$ -particle condensates are reviewed along with a discussion of their experimental indicators, with a focus on precision break-up measurements. Two experiments are discussed in detail, firstly concerning the break-up of $^{12}$ C and then the decays of heavier nuclei. With more theoretical input, and increasingly complex detector setups, precision break-up measurements can, in principle, provide insight into the structures of states in $α$ -conjugate nuclei. However, the commonly-held belief that the decay of a condensate state will result in $N$ $α$ -particles is challenged. We further conclude that unambiguously characterising excited states built on $α$ -condensates is difficult, despite improvements in detector technology.
↳ nucl-exnucl-thFew Body Syst.(2020)·8 citations
10
Xenon Isotopes Identify Large-scale Nucleosynthetic Heterogeneities across the Solar System
Guillaume Avice🇫🇷 · Manuel Moreira🇫🇷 · Jamie D Gilmour🇬🇧
Nucleosynthetic isotopic anomalies in meteorites and planetary objects contribute to our understanding of the formation of the solar system. Isotope systematics of chondrites demonstrate the existence of a physical separation between isotopic reservoirs in the solar system. The isotopic composition of atmospheric xenon (Xe) indicates that its progenitor, U-Xe, is depleted in 134Xe and 136Xe isotopes relative to Solar or Chondritic end-members. This deficit supports the view that nucleosynthetic heterogeneities persisted during the Solar System formation. Measurements of xenon emitted from comet 67P/Churyumov-Gerasimenko (67P) identified a similar, but more extreme, deficit of cometary gas in these isotopes relative to Solar gas. Here we show that the data from 67P demonstrate that two distinct sources contributed xenon isotopes associated with the r-process to the solar system. The h-process contributed at least 29% (2sigmas) of solar system 136Xe. Mixtures of these r-process components and the s-process that match the heavy isotope signature of cometary Xe lead to depletions of the precursor of atmospheric Xe in p-only isotopes. Only the addition of pure p-process Xe to the isotopic mixture brings 124Xe/132Xe and 126Xe/132Xe ratios back to solar-like values. No pure p-process Xe has been detected in solar system material, and variation in p-process Xe isotopes is always correlated with variation in r-process Xe isotopes. In the solar system, p-process incorporation from the interstellar medium happened before incorporation of r-process nuclides or material in the outer edge of the solar system carries a different mixture of presolar sources as have been preserved in parent bodies.
↳ astro-ph.EPnucl-thApJ(2020)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE

A New Heavy Flavor Program for the Future Electron-Ion Collider

Transport properties in magnetized compact stars

The Hoyle Family: The search for alpha-condensate states in light nuclei

Xenon Isotopes Identify Large-scale Nucleosynthetic Heterogeneities across the Solar System

Affiliations