Many decays of light baryons consisting of light $u,d,s$ quarks have been measured, and these measurements will help us to understand the decay properties of light baryons. In this work, we study two-body nonleptonic weak decays of light baryon octet $(T_8)$ and baryon decuplet $(T_{10})$ by the topological diagram approach (TDA) under the SU(3) flavor symmetry for the first time. We find that (1) the TDA and the SU(3) irreducible representation approach (IRA) match consistently in $T_{10}\to T^{(')}_{8,10}P_8$ ($P_8$ is the light pseudoscalar meson octet); (2) almost all relevant not-yet-measured $\mathcal{B}(T_{10}\to T_8 P_8)$ may be predicted by using three experimental data of $\mathcal{B}(Ω^-\to Ξ^0π^-,Ξ^-π^0,Λ^0K^-)$, and the upper limits of $\mathcal{B}(T_{10}\to T{'}_{10}π^-)$ may be obtained from the experimental upper limit of $\mathcal{B}(Ω^-\to Ξ^{*0}π^-)$ by both the TDA and the IRA together, nevertheless, all new predicted branching ratios are too small to br reached in current experiments; (3) $T_8\to T'_8 P_8$ decays are quite complex in terms of the TDA, and we find that W-exchange diagrams give large and even dominant contributions by using relevant experimental data and the isospin relations.
We systematically study two-body nonleptonic decays of light lambda hyperon $Λ\to p π^- (nπ^0)$ with account for both short- and long-distance effects. The short-distance effects are induced by five topologies of external and internal weak $W^\pm$ exchange, while long-distance effects are saturated by an inclusion of the so-called pole diagrams with intermediate $\frac{1}{2}^+$ and $\frac{1}{2}^-$ baryon resonances. The contributions from $\frac12^+$ resonances are calculated straightforwardly by account for nucleon and $Σ$ baryons whereas the contributions from $\frac{1}{2}^-$ resonances are …
The semileptonic decays and two-body nonleptonic decays of light baryon octet ($T_8$) and decuplet ($T_{10}$) consisting of light $u,d,s$ quarks are studied with the SU(3) flavor symmetry in this work. We obtain the amplitude relations between different decay modes by the SU(3) irreducible representation approach, and then predict relevant branching ratios by present experimental data within $1 σ$ error. We find that the predictions for all branching ratios except $\mathcal{B}(Ξ\rightarrow Λ^0π)$ and $\mathcal{B}(Ξ^*\rightarrow Ξπ)$ are in good agreement with present experimental data, that im…
We present a concise overview on $CP$ violation in hyperon decays, including past, present, and future efforts to search for it. We highlight in particular the most recent results of the BESIII experiment using a quantum-entangled pair of hyperon and antihyperon produced by a charmonium resonance formed in $e^+e^-$ annihilation. The subsequent nonleptonic decays of these hyperon pairs allow for the simultaneous determination of various parameters pertaining to $CP$ violation in the decays. We compare the reported data with the corresponding current predictions for $CP$ asymmetries within the s…
We shed new light on the standard current algebra approach to the nonleptonic two-body decays of single and double heavy charm baryons. By making use of the completeness relation for the flavor wave functions of the ground state baryon {\bf 20'} representation we are able to rewrite the results of the current algebra approach in terms of the seven topological tensor invariants describing the decays. The representation of the current algebra results in terms of topological tensor invariants depends only on the initial and final state of the process. The summation over intermediate states inhere…
$Λ$ hyperons in core-collapse supernovae: Equilibration and neutrino opacities
Instituto de Astrofísica de Canarias（加那利天体物理研究所）；Universidad de La Laguna, Departamento de Astrofísica（拉古纳大学天体物理学系）；LAPTh, CNRS, USMB（拉尼永理论物理实验室，法国国家科学研究中心，萨瓦大学）；CERN, Theoretical Physics Department（欧洲核子研究组织，理论物理部）；Institute of Theoretical Physics, Wrocław University of Science and Technology（弗罗茨瓦夫科技大学理论物理研究所）；Research Center for Computational Physics and Data Processing, Institute of Physics, Silesian University in Opava（俄帕瓦西里西亚大学物理研究所计算物理与数据处理研究中心）
Tsung-Dao Lee Institute and School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院）；School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院）；Institute of Quantum Matter, South China Normal University（华南师范大学量子物质研究所）；School of Physics and Astronomy, Monash University（蒙纳士大学物理与天文学院）
Studying baryon number transport dynamics via hyperon-kaon correlations in $p + \mathrm{Au}$ collisions at $\sqrt{s_{_{\rm NN}}}=20$, $39$ and $62$ GeV
Key Laboratory of Nuclear Physics and Ion-beam Application (MOE), Fudan University（核物理与离子束应用教育部重点实验室，复旦大学）
In this work we extend our formalism to study meson-baryon interactions by including $s$- and $u$-channel diagrams for pseudoscalar-baryon systems. We study the coupled systems with strangeness $-1$ and focus on studying the isospin-1 resonance(s), especially in the energy region around 1400 MeV. By constraining the model parameters to fit the cross section data available on several processes involving relevant channels, we find resonances in the isoscalar as well as the isovector sector in the energy region around 1400 MeV.
A depth of $D_Λ\approx -28$ MeV for the $Λ$-nucleus potential was confirmed in 1988 by studying $Λ$ binding energies deduced from $(π^+,K^+)$ spectra measured across the periodic table. Modern two-body hyperon-nucleon interaction models require additional interaction terms, most likely $ΛNN$ three-body terms, to reproduce $D_Λ$. In this work we apply a suitably constructed $Λ$-nucleus density dependent optical potential to binding energy calculations of observed $1s_Λ$ and $1p_Λ$ states in the mass range $12\leq A\leq 208$. The resulting $ΛNN$ contribution to $D_Λ$, about 14 MeV repulsion at s…
