Density-dependent effective baryon-baryon interaction from chiral three-baryon forces

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• 作者：Stefan Petschauer^a ; ^{stefan.petschauer@ph.tum.de} ; Johann Haidenbauer^b ; Norbert Kaiser^a ; Ulf-G. Meiß ; ner^b ; ^c ; ^d ; Wolfram Weise^a
• 关键词：Chiral effective field theory ; Three-baryon forces ; Hyperons ; Nuclear matter
• 刊名：Nuclear Physics A
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：957
• 期：Complete
• 页码：347-378
• 全文大小：741 K
• 卷排序：957

文摘

A density-dependent effective potential for the baryon–baryon interaction in the presence of the (hyper)nuclear medium is constructed, based on the leading (irreducible) three-baryon forces derived within SU(3) chiral effective field theory. We evaluate the contributions from three classes: contact terms, one-pion exchange and two-pion exchange. In the strangeness-zero sector we recover the known result for the in-medium nucleon–nucleon interaction. Explicit expressions for the ΛN in-medium potential in (asymmetric) nuclear matter are presented. Our results are suitable for implementation into calculations of (hyper)nuclear matter. In order to estimate the low-energy constants of the leading three-baryon forces we introduce the decuplet baryons as explicit degrees of freedom and construct the relevant terms in the minimal non-relativistic Lagrangian. With these, the constants are estimated through decuplet saturation. Utilizing this approximation we provide numerical results for the effect of the three-body force in symmetric nuclear matter and pure neutron matter on the ΛN interaction. A moderate repulsion that increases with density is found in comparison to the free ΛN interaction.