Nuclear Symmetry Energy from QCD sum rules

Abstract

We calculate the nucleon self-energies in isospin-asymmetric nuclear matter using QCD sum rules. Taking the difference of these for the neutron and proton enables us to express the potential part of the nuclear symmetry energy in terms of local operators. We find that the scalar (vector) self-energy part gives a negative (positive) contribution to the nuclear symmetry energy which is consistent with the results from relativistic mean-field theories. Moreover, we find that an important contribution to the negative contribution of the scalar self-energy comes from the twist-4 matrix elements, whose leading density dependence can be extracted from deep inelastic scattering experiments. This suggests that the twist-4 contribution partly mimics the exchange of the $\delta$ meson and that it constitutes an essential part in the origin of the nuclear symmetry energy from QCD. Our result also extends an early success of QCD sum rule method in understanding the symmetric nuclear matter in terms of QCD variables to the asymmetric nuclear matter case.

Revised as the published version with 9 figures (18 graphs), 20 pages. Typographical errors and errors in computational codes are corrected. Missed OPE term is included

References in corpus (4)

• Nuclear matter symmetry energy and the symmetry energy coefficient in the mass formula
• Four-Quark Condensates in Nucleon QCD Sum Rules
• An improved single particle potential for transport model simulations of nuclear reactions induced by rare isotope beams
• The role of the in-medium four-quark condensates revised

Cited by in corpus (12)

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• New determination of $\mathcal{S}\mathcal{T}⟨N|\overline{q}{D}_{\mu }{D}_{\nu }q|N⟩$ based on recent experimental constraints
• Charmed Baryon ${\Lambda }_c$ in Nuclear Matter
• Nucleon axial-vector coupling constant in magnetar environments
• Negative-parity nucleon excited state in nuclear matter
• Relativistic self-energy decomposition of nuclear symmetry energy and equation of state of neutron matter within QCD sum rules
• QCD sum rules for the neutron, $\Sigma$, and $\Lambda$ in neutron matter
• Symmetry energy in cold dense matter
• QCD sum rules for the $\Delta$ isobar in neutron matter
• Neutron matter within QCD sum rules
• Finite-energy sum rules at finite chemical potential and zero temperature