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arXiv 0709.0077nucl-thastro-phhep-ph
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核束缚对强子质量变化的依赖性

Dependence of nuclear binding on hadronic mass variation

V. V. Flambaum, R. B. Wiringa

摘要:

我们研究如何结合轻($A\leq 8$)核取决于可能的变化的强子质量,包括介子,核子和核子共振质量。随着时间的推移,强子质量可能会发生微小的变化,目前的结果可以帮助评估大爆炸核合成的后果。更大的变化可能与目前试图从格点量子色动力学计算中推断核子-核子相互作用性质有关。结果被呈现为相对于不同质量的能量的导数,因此它们可以与强子质量依赖于底层的电流夸克质量$m_q$的不同预测相结合。作为一个例子,我们采用一组特定的关系从研究强子质量和sigma条款的基础上戴森Schwinger方程和庞加莱协变Faddeev方程的限制夸克和双夸克。我们发现,随着夸克质量的增加,核的结合力会适度迅速地减少,当π介子质量增加$\sim$ 60%(对应于$X_q=m_q/Λ_{QCD}$增加2.5)时,氘核就会变得不受束缚。在另一个方向上,如果π介子质量减少$\sim$ 15%(对应于$X_q$减少$\sim$ 30%),双中子就会被束缚。如果我们把大爆炸核合成计算和测量之间的不一致解释为$X_q$变化的结果,我们就得到一个估计值$δX_q/X_q=K \cdot (0.013 \pm 0.002)$,其中$K \sim 1$($K$的预期精度大约是2的一个因子)。结果以$^7$ Li数据为主。

英文摘要:

We examine how the binding of light ($A\leq 8$) nuclei depends on possible variations of hadronic masses, including meson, nucleon, and nucleon-resonance masses. Small variations in hadronic masses may have occurred over time; the present results can help evaluate the consequences for big bang nucleosynthesis. Larger variations may be relevant to current attempts to extrapolate properties of nucleon-nucleon interactions from lattice QCD calculations. Results are presented as derivatives of the energy with respect to the different masses so they can be combined with different predictions of the hadronic mass-dependence on the underlying current-quark mass $m_q$. As an example, we employ a particular set of relations obtained from a study of hadron masses and sigma terms based on Dyson-Schwinger equations and a Poincaré-covariant Faddeev equation for confined quarks and diquarks. We find that nuclear binding decreases moderately rapidly as the quark mass increases, with the deuteron becoming unbound when the pion mass is increased by $\sim$60% (corresponding to an increase in $X_q=m_q/Λ_{QCD}$ of 2.5). In the other direction, the dineutron becomes bound if the pion mass is decreased by $\sim$15% (corresponding to a reduction of $X_q$ by $\sim$30%). If we interpret the disagreement between big bang nucleosynthesis calculations and measurements to be the result of variation in $X_q$, we obtain an estimate $δX_q/X_q=K \cdot (0.013 \pm 0.002)$ where $K \sim 1$ (the expected accuracy in $K$ is about a factor of 2). The result is dominated by $^7$Li data.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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