### 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 δ 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.

Original language | English |
---|---|

Article number | 015204 |

Journal | Physical Review C - Nuclear Physics |

Volume | 87 |

Issue number | 1 |

DOIs | |

Publication status | Published - 2013 Jan 22 |

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### All Science Journal Classification (ASJC) codes

- Nuclear and High Energy Physics

### Cite this

*Physical Review C - Nuclear Physics*,

*87*(1), [015204]. https://doi.org/10.1103/PhysRevC.87.015204

}

*Physical Review C - Nuclear Physics*, vol. 87, no. 1, 015204. https://doi.org/10.1103/PhysRevC.87.015204

**Nuclear symmetry energy from QCD sum rules.** / Jeong, Kie Sang; Lee, Su Houng.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Nuclear symmetry energy from QCD sum rules

AU - Jeong, Kie Sang

AU - Lee, Su Houng

PY - 2013/1/22

Y1 - 2013/1/22

N2 - 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 δ 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.

AB - 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 δ 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.

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U2 - 10.1103/PhysRevC.87.015204

DO - 10.1103/PhysRevC.87.015204

M3 - Article

VL - 87

JO - Physical Review C - Nuclear Physics

JF - Physical Review C - Nuclear Physics

SN - 0556-2813

IS - 1

M1 - 015204

ER -