Study of Spin Structure of the Proton and Nectron with Hadror Coincidence Method

哈德罗符合法研究质子和中子的自旋结构

基本信息

批准号：
09304030
负责人：
SHIBATA Toshi-aki
金额：
$ 13.7万
依托单位：
TOKYO INSTITUTE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

In this project we have done 1) the experimental data analysis and 2) detector development at Tokyo Institute of Technology. The thema oa the project was the study of the quark-gluon structure of the spin of proton and neutron. The spin of the nucleon is 1/2. It was found by EMC in 1988 that only a small part of the nucleon spin is carried by quarks. We are participating in HERMES experiment at DESY in Hamburg in Germany. At HERMES the high energy polarized electron beam is scattered off the polarized nucleon target. The experimental data are sent from HERMES to our university. This experiment is a deep inelastic scattering. We mea sured not only the scattered electron but also produced hadrons (mesons, nucleons, lambda etc.) in coincidence. For that purpose we developped a Ring Imag ing CHerenkov counter (RICH) and installed into HERMES.Pions, kaons, protons and anti-protons at 2-20Gev/c are identified with the RICH.Polarized u, d, and s quark distributions in the nucleon are determined.Furthremore, transversity of the quark spin was studied for the first time. This is a study of the distribution of the quark whose spin is perpendicular to the nucleon spin. At HERMES the angle between the electron scattering plane and the pion production direction was measured by reversing the target nucleon spin direction. We succeeded to observe a non-zero asymmetry. 'Transversity' of the quark spin is a new field and will attract many physicists in the near future to study it further.

在这个项目中，我们完成了1）实验数据分析和2）东京理工学院的检测器开发。该项目是对质子和中子旋转的夸克 - 糖结构的研究。细胞核的自旋为1/2。 EMC在1988年发现，只有一小部分核子旋转是由夸克携带的。我们正在德国汉堡的Desy参加爱马仕实验。在爱马仕（Hermes），高能量极化电子束散落在极化核子目标上。实验数据是从爱马仕发送到我们大学的。该实验是深层的非弹性散射。我们不仅介绍了散射的电子，还介绍了同时发生的黑龙（介子，核子，lambda等）。为这个目的，我们开发了一个戒指的成像Cherenkov柜台（富），并安装到爱马仕（Hermes）中。在2-20gev/c处识别p，kaons，kaons，proton和proton和抗蛋白酶，并用富有富的U，D和S Quark分布在原子核中确定。FULTHREMORE.FULTHREMTHEMORE.FULTHREMTHEMORE，FULTHREMTHEMORE，FULTHREMTHEMORE，FULTHRESTINE，FULTHRESTINE，FLESTRESSITY of QUARK SPITS for Quark Spin进行了第一次研究。这是对夸克的分布的研究，其自旋垂直于核子自旋。在爱马仕（Hermes），通过逆转目标核子自旋方向来测量电子散射平面和Pion产生方向之间的角度。我们成功地观察了非零的不对称性。夸克旋转的“横向性”是一个新领域，将在不久的将来吸引许多物理学家进一步研究。