核子σ项在$m_\pi=222~\rm MeV$下的变分分析：来自格点QCD的研究
Nucleon-sigma terms at $m_π=222 ~\rm MeV$ with a variational analysis from lattice QCD
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中文总结 AI 辅助
本文通过格点QCD变分分析，在$m_\pi=222~\rm MeV$下研究核子σ项，利用$N$和$N\sigma$算符基抑制激发态污染，并考察对$N\pi\pi$态的去除效果。
中文摘要 AI 辅助
核子σ项对于核子质量的分解以及涉及标量相互作用的标准模型之外的新物理搜寻具有重要意义。格点QCD与唯象学确定结果之间持续存在的张力可能源于格点QCD分析中未受控的激发态污染。在先前$m_\pi=429~\rm MeV$的工作中，我们表明这种污染由$N\sigma$态主导，并且可以通过使用$N$和$N\sigma$算符的变分分析得到强烈抑制。在本次报告中，我们展示了在$m_\pi=222~\rm MeV$下的初步结果，其中σ变得不稳定并衰变为$\pi\pi$。我们研究了相同的小型变分基能否通过$N\sigma$算符与这些态的重叠来消除预期的$N\pi\pi$污染。
英文摘要
Nucleon sigma terms are important for the decomposition of the nucleon mass and for searches for new physics beyond the Standard Model involving scalar interactions. A persistent tension between lattice QCD and phenomenological determinations may be due to uncontrolled excited-state contamination in lattice QCD analyses. In previous work at $m_π=429~\rm MeV$, we showed that this contamination is dominated by $Nσ$ states and can be strongly suppressed with a variational analysis using $N$ and $Nσ$ operators. In this talk, we present preliminary results at $m_π=222~\rm MeV$, where the $σ$ becomes unstable and decays into $ππ$. We investigate whether the same small variational basis can remove the expected $Nππ$ contamination through the overlap of the $Nσ$ operator with these states.
