We review the predictions of quark models for multiquark configurations that are bound or resonant states,and compare different methods for estimating the properties of resonances.
We revisit the hyperon weak radiative decays in the framework of the non-relativistic constituent quark model. This study confirms the nonlocal feature of the hyperon weak radiative transition operators, which are dom...We revisit the hyperon weak radiative decays in the framework of the non-relativistic constituent quark model. This study confirms the nonlocal feature of the hyperon weak radiative transition operators, which are dominated by the pole terms, and an overall self-consistent description of the available experimental data for the Cabibbofavored hyperon weak radiative decays is presented. It provides a natural mechanism for evading the Hara theorem,where sizeable parity-violating contributions can come from the intermediate orbital excitations. Cancellations between pole terms also explain the significant SU(3) flavor symmetry breaking manifested by the experimental data. We also discuss several interesting selection rules arising from either the electromagnetic or the weak interaction vertices. These features suggest nontrivial relations among various hyperon decays.展开更多
Since several decades, a particular attention has been devoted to hadrons with anomalous properties [1–5]. On the experimental side, the search has been very difficult and disappointing. For instance, in the early 60...Since several decades, a particular attention has been devoted to hadrons with anomalous properties [1–5]. On the experimental side, the search has been very difficult and disappointing. For instance, in the early 60’s, there has been some claims for baryon resonances with strangeness S=+1, the so-called Z baryons, while the established baryons have either S=0 or S < 0. But the Z spectrum was based on somewhat hazardous analyses of K+-nucleon scattering data without spin observables, and it faded away. It reappeared under the name of θ pentaquark, but it was never firmly established.展开更多
We discuss model-independent constraints on spin observables in exclusive and inclusive reactions, with special attention to the case of photoproduction.
文摘We review the predictions of quark models for multiquark configurations that are bound or resonant states,and compare different methods for estimating the properties of resonances.
基金Supported by the National Natural Science Foundation of China(11425525,11521505)DFG and NSFC funds to the Sino-German CRC 110“Symmetries and the Emergence of Structure in QCD”(NSFC)(11261130311)+3 种基金Strategic Priority Research Program of Chinese Academy of Sciences(XDB34030302)National Key Basic Research Program of China(2015CB856700)supported by the research startup funding at SCNU,Guangdong Provincial funding with(2019QN01X172)Science and Technology Program of Guangzhou(2019050001)。
文摘We revisit the hyperon weak radiative decays in the framework of the non-relativistic constituent quark model. This study confirms the nonlocal feature of the hyperon weak radiative transition operators, which are dominated by the pole terms, and an overall self-consistent description of the available experimental data for the Cabibbofavored hyperon weak radiative decays is presented. It provides a natural mechanism for evading the Hara theorem,where sizeable parity-violating contributions can come from the intermediate orbital excitations. Cancellations between pole terms also explain the significant SU(3) flavor symmetry breaking manifested by the experimental data. We also discuss several interesting selection rules arising from either the electromagnetic or the weak interaction vertices. These features suggest nontrivial relations among various hyperon decays.
文摘Since several decades, a particular attention has been devoted to hadrons with anomalous properties [1–5]. On the experimental side, the search has been very difficult and disappointing. For instance, in the early 60’s, there has been some claims for baryon resonances with strangeness S=+1, the so-called Z baryons, while the established baryons have either S=0 or S < 0. But the Z spectrum was based on somewhat hazardous analyses of K+-nucleon scattering data without spin observables, and it faded away. It reappeared under the name of θ pentaquark, but it was never firmly established.
文摘We discuss model-independent constraints on spin observables in exclusive and inclusive reactions, with special attention to the case of photoproduction.
