Report
QCD $\theta$-vacua from the chiral limit to the quenched limit
| العنوان: | QCD $\theta$-vacua from the chiral limit to the quenched limit |
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| المؤلفون: | Mameda, Kazuya |
| المصدر: | Nucl. Phys. B 889, 712 (2014) |
| سنة النشر: | 2014 |
| المجموعة: | High Energy Physics - Phenomenology |
| مصطلحات موضوعية: | High Energy Physics - Phenomenology |
| الوصف: | We investigate the dependence of the QCD vacuum structure on the $\theta$-angle and quark mass, using the Di-Vecchia--Veneziano model. Although the Di-Vecchia--Veneziano model is a chiral effective model, it contains the topological properties of the pure Yang--Mills theory. It is shown that within this model, the ground state energies for all $\theta$ are continuous functions of quark mass from the chiral limit to the quenched limit, even including the first order phase transition at $\theta = \pi$. Based on this effective model, we discuss (i) how the ground state depends on quark mass, and (ii) why the phase transition at $\theta = \pi$ is present both in the chiral and quenched limit. In order to analyze the relation between quark mass and the $\theta$-vacua, we calculate the chiral condensate as a function of quark mass. Also, considering the presence of the innate metastable states included in the QCD $\theta$-vacuum, we also give a unified understanding of the phase transitions at $\theta = \pi$ in the chiral and quenched limit. Comment: 18 pages, 8 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1016/j.nuclphysb.2014.11.002 |
| URL الوصول: | http://arxiv.org/abs/1408.1189 |
| رقم الانضمام: | edsarx.1408.1189 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1016/j.nuclphysb.2014.11.002 |
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