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| Main Authors: | , , , |
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| Format: | Preprint |
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2024
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| Subjects: | |
| Online Access: | https://arxiv.org/abs/2402.12726 |
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| _version_ | 1866910336564592640 |
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| author | Nieves, J. Feijoo, A. Albaladejo, M. Du, Meng-Lin |
| author_facet | Nieves, J. Feijoo, A. Albaladejo, M. Du, Meng-Lin |
| contents | We present a detailed study of the lowest-lying ${\frac{1}{2}}^-$ and ${\frac{3}{2}}^-$ $Λ_{Q}$ 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 $Λ_b(5912)$ [$J^P=1/2^-$], $Λ_b(5920)$ [$J^P=3/2^-$] and the $Λ_c(2625)$ [$J^P=3/2^-$], and the $Λ(1520)$ [$J^P=3/2^-$] admitting larger breaking corrections, are heavy-quark spin-flavor siblings. They can be seen as dressed quark-model states with $Σ_{Q}^{(*)}π$ molecular components of the order of 30\%. The ${J^P=\frac{1}{2}}^-$ $Λ_c(2595)$ 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 $Σ_cπ$ 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 $Λ_b(5912)$, $Λ_b(5920)$ and $Λ_c(2625)$, the $Λ_c(2595)$ should not be considered as a heavy-quark spin-flavor partner of the former ones. We also show that the $Λ(1405)$ 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 $Λ_b(6070)$ and two $Λ_c(2765)$ heavy-quark spin and flavor sibling odd parity states. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2402_12726 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Lowest-lying ${\frac{1}{2}}^-$ and ${\frac{3}{2}}^-$ $Λ_{Q}$ resonances: from the strange to the bottom sectors Nieves, J. Feijoo, A. Albaladejo, M. Du, Meng-Lin High Energy Physics - Phenomenology We present a detailed study of the lowest-lying ${\frac{1}{2}}^-$ and ${\frac{3}{2}}^-$ $Λ_{Q}$ 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 $Λ_b(5912)$ [$J^P=1/2^-$], $Λ_b(5920)$ [$J^P=3/2^-$] and the $Λ_c(2625)$ [$J^P=3/2^-$], and the $Λ(1520)$ [$J^P=3/2^-$] admitting larger breaking corrections, are heavy-quark spin-flavor siblings. They can be seen as dressed quark-model states with $Σ_{Q}^{(*)}π$ molecular components of the order of 30\%. The ${J^P=\frac{1}{2}}^-$ $Λ_c(2595)$ 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 $Σ_cπ$ 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 $Λ_b(5912)$, $Λ_b(5920)$ and $Λ_c(2625)$, the $Λ_c(2595)$ should not be considered as a heavy-quark spin-flavor partner of the former ones. We also show that the $Λ(1405)$ 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 $Λ_b(6070)$ and two $Λ_c(2765)$ heavy-quark spin and flavor sibling odd parity states. |
| title | Lowest-lying ${\frac{1}{2}}^-$ and ${\frac{3}{2}}^-$ $Λ_{Q}$ resonances: from the strange to the bottom sectors |
| topic | High Energy Physics - Phenomenology |
| url | https://arxiv.org/abs/2402.12726 |