تقرير
Lowest-lying ${\frac{1}{2}}^-$ and ${\frac{3}{2}}^-$ $\Lambda_{Q}$ resonances: from the strange to the bottom sectors
| العنوان: | Lowest-lying ${\frac{1}{2}}^-$ and ${\frac{3}{2}}^-$ $\Lambda_{Q}$ resonances: from the strange to the bottom sectors |
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| المؤلفون: | Nieves, J., Feijoo, A., Albaladejo, M., Du, Meng-Lin |
| سنة النشر: | 2024 |
| المجموعة: | High Energy Physics - Phenomenology |
| مصطلحات موضوعية: | High Energy Physics - Phenomenology |
| الوصف: | We present a detailed study of the lowest-lying ${\frac{1}{2}}^-$ and ${\frac{3}{2}}^-$ $\Lambda_{Q}$ resonances both in the heavy quark (bottom and charm) and the strange sectors. We have paid special attention to the interplay between the constituent quark-model and chiral baryon-meson degrees of freedom, which are coupled using a unitarized scheme consistent with leading-order heavy quark symmetries. We show that the $\Lambda_b(5912)$ [$J^P=1/2^-$], $\Lambda_b(5920)$ [$J^P=3/2^-$] and the $\Lambda_c(2625)$ [$J^P=3/2^-$], and the $\Lambda(1520)$ [$J^P=3/2^-$] admitting larger breaking corrections, are heavy-quark spin-flavor siblings. They can be seen as dressed quark-model states with $\Sigma_{Q}^{(*)}\pi$ molecular components of the order of 30\%. The ${J^P=\frac{1}{2}}^-$ $\Lambda_c(2595)$ has, however, a higher molecular probability of at least $50$\%, and even values greater than 70\% can be easily accommodated. This is because it is located almost on top of the threshold of the $\Sigma_c\pi$ pair, which largely influences its properties. Although the light degrees of freedom in this resonance would be coupled to spin-parity $1^-$ as in the $\Lambda_b(5912)$, $\Lambda_b(5920)$ and $\Lambda_c(2625)$, the $\Lambda_c(2595)$ should not be considered as a heavy-quark spin-flavor partner of the former ones. We also show that the $\Lambda(1405)$ chiral two-pole pattern does not have analogs in the $\frac{1}{2}^-$ charmed and bottomed sectors, because the $ND^{(*)}$ and $N\overline{B}{}^{(*)} $ channels do not play for heavy quarks the decisive role that the $N \overline{K}$ does in the strange sector, and the notable influence of the bare quark-model states for the charm and bottom resonances. Finally, we predict the existence of two $\Lambda_b(6070)$ and two $\Lambda_c(2765)$ heavy-quark spin and flavor sibling odd parity states. Comment: 41 pages, 13 figures, and 7 tables |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2402.12726 |
| رقم الأكسشن: | edsarx.2402.12726 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |