Constraining the strangeness content of the nucleon by measuring the ϕ meson mass shift in nuclear matter
Constraining the strangeness content of the nucleon by measuring the ϕ meson mass shift in nuclear matter
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通过测量核物质中的介子质量位移来限制核子的奇异含量
DOI：
10.1103/physrevd.90.094002
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发表时间：
2014
影响因子：
5
通讯作者：
Keisuke Ohtani
中科院分区：
文献类型：
--
作者：
Philipp Gubler;Keisuke Ohtani
利用QCD求和规则方法和最大熵方法，研究了有限密度下介子的行为。证明了核物质中可能发生的质量位移与核子的奇异性含量密切相关，而奇异性含量与奇异项${\ensuremath{\sigma}}_{sN}={m}_{s}⟨N|\overline{s}s|N⟩$.成正比我们的结果进一步表明，在核物质密度处，介子可以得到正的或负的质量漂移，这取决于它的取值。我们发现，这些结果仅弱地依赖于对峰值宽度的潜在修改，以及对有限密度下四夸克凝聚体行为的假设。为了检验我们结果的稳定性，我们考虑了算符乘积展开的几个高阶修正，包括${\ensureath{\α}}_{S}$修正，奇异夸克质量中的更高阶项，以及以前工作中没有考虑到的更高扭度项。
The behavior of the $\ensuremath{\phi}$ meson at finite density is studied, making use of a QCD sum rule approach in combination with the maximum entropy method. It is demonstrated that a possible mass shift of the $\ensuremath{\phi}$ in nuclear matter is strongly correlated to the strangeness content of the nucleon, which is proportional to the strange sigma term, ${\ensuremath{\sigma}}_{sN}={m}_{s}⟨N|\overline{s}s|N⟩$. Our results furthermore show that, depending on the value of ${\ensuremath{\sigma}}_{sN}$, the $\ensuremath{\phi}$ meson could receive both a positive or negative mass shift at nuclear matter density. We find that these results depend only weakly on potential modifications of the width of the $\ensuremath{\phi}$ peak and on assumptions made on the behavior of four-quark condensates at finite density. To check the stability of our findings, we take into account several higher order corrections to the operator product expansion, including ${\ensuremath{\alpha}}_{s}$-corrections, terms of higher order in the strange quark mass, and terms of higher twist that have not been considered in earlier works.