Search for Duble Lambda Hypernuclei

1.我们在美国布鲁克海文国家实验室的AGS加速器上进行了双Λ超核，特别是^4<_<ΛΛ>H>的实验。然而，由于预算问题，所有使用质子在固定靶上的实验都被推迟。在研制过程中，我们研制了一种新型阴极读出室。此外，一些理论小组也在尝试计算^4&lt;_&lt;ΛΛ&gt;H&gt;质量，这对提取λ-λ相互作用非常重要，并等待实验结果。2.我们在KEK的PS加速器上首次利用（π^-，K^+）反应在^ B靶上产生了丰中子超核<10>。这项研究对于理解超核中的Λ-π耦合以及中子星等致密核物质中的超子混合都是非常重要的。我们已经成功地观测到了^<10>&lt;_ΛLi&gt;的束缚态，这将导致更多奇异超核的产生，如^6&lt;_ΛH&gt;。我们还获得了通过双电荷交换反应准自由产生Λ、Λ ^-和Λ的数据，这将有助于提取Λ ^-核中间体。

1.We have prepared the experiment to identify double-Λ hypernuclei, in particular ^4<_<ΛΛ>H>, at AGS accelerator of Brookhaven National Laboratory in US. However all the experiments by using protons on fixed target have been postponed due to budgetary problem. During the preparation period we have developed a new type of cathode readout chamber. In addition several theoretical groups have been trying to calculate the ^4<_<ΛΛ>H> mass, which is very important to extract lambda-lambda interaction, and await the experimental result.2.We have carried out the experiment to produce a neutron-rich hypercleus for the first time at PS accelerator of KEK by using (π^-,K^+) reaction on ^<10>B target. This study is quite important in order to understand the Λ-Σ coupling in hypernuclei as well as hyperon mixing in dense nuclear matter like neutron stars. We have successfully observed bound states of ^<10><_ΛLi>, which will lead to the production of more exotic hypernuclei such as ^6<_ΛH>. We also took data on the quasi-free production of Λ, Σ^-as well as Λ via double charge-exchange reaction, which will help to extract the Σ^--nucleus interction.