Search for Exotic Mesons with High Precision Gamma-ray Detector (GAMS)

寻找非qq奇异介子（胶球、杂化等）的实验以及新的手征对称粒子（sigma等）使用450 GeV的超级质子同步加速器在欧洲核子研究中心和70 GeV的质子同步加速器在IHEP（俄罗斯）在KEK在12 GeV的质子同步加速器的实验进行，并在每个研究所得到的数据进行了分析。在欧洲核子研究中心（CERN），中心产生反应pp→p_sX^0p_f（X^0=π^+ π^-，π^0π^0，η η等）被成功地应用于探测器和前端电子学研究。在IHEP和KEK上主要研究了电荷交换反应π^-p→ X^0nX ^-p（X^0= η π^0等，X^-=η π^-等），并在相关通道（η η，η η'等）中证实了我们GAMS小组于1983年首次发现的一个初级标量胶球候选者f_0（1500）/G1590）。通过对CERN和IHEP数据的新分析，KEK发现的η π^-通道中的非qq 1^<-+>态被另外两个小组（BNL的MPS和IHEP的VES）证实。 关于我们 WA 102小组利用具有带电粒子和γ探测能力及粒子鉴别能力的OMEGA谱仪研究了π的衰变通道，并与日本大学理论小组合作研究了π的手征伙伴σ介子（Goldstone玻色子）。在许多产生反应（pp中心碰撞、J/φ衰变、D衰变等）的π^0π^0通道中，在500 MeV质量区附近都能看到这种介子。针对散射过程中20多年来一直未能解决的难题，利用多个研究组的新思想和日本大学研究组的新方法，研制了一种采用新材料钨酸铅（PWO）的新型电磁量能器速端示波器样机，并进行了成功的实验。介绍了一种用于高速（小于1 μ sec）ADC的新型全定制IC芯片。和高线性分辨率（10 bits以上）的研制成功，具有世界最高水平。这些工作是根据KEK和IHEP之间的合作协议进行的。该协议一直持续到2005年10月。少

Experiments of search for non-qq exotic mesons (glueballs, hybrids etc.) and new chiral symmetry particles (sigma etc.) were performed using 450GeV Super Proton Synchrotron at CERN and 70GeV Proton Synchrotron at IHEP (Russia) in relation with experiments at 12GeV Proton Synchrotron at KEK, and the obtained data were analyzed at each institute. R＆D works of detectors and front end electronics were also done in the framework of the GAMS collaboration.At CERN, central production reactions pp→p_sX^0p_f (X^0=π^+ π^-, π^0π^0, η η etc.) were studied and at IHEP and KEK, charge exchange reactions π^-p→X^0n X^-p (X^0= η π^0 etc.X^-=η π^- etc) are mainly persued.A primary scalar glueball candidate f_0(1500)/G1590) which was found firstly by our GAMS group in 1983, was confirmed in relevant channels (η η, η η' etc.) by the new analyses of CERN and IHEP dataA non-qq 1^<-+> state in the η π^- channel found at KEK was confirmed by other two group (MPS at BNL and VES at IHEP).Many resonances in many … More decay channels were studied by our WA102 group using the OMEGA spectrometer with detection capability of charged particles and gammas and particle identification.The sigma meson, a chiral partner of π as a Goldstone boson, was studied with collaboration with the theoretical group of Nihon University. This meson was seen around the 500 MeV mass region in π^0π^0 channel of many production reactions (pp central collision, J/φ decay, D decay etc.). The difficult problems in the scattering process, which had not been solved for 20 years, was studied and solved on new ideas of several groups and the new method of Nihon-Univ.group.A prototype of a new electromagnetic calorimeter hodoscope using new material, lead tungstate (PWO) was built and successfully tested. A new full-custom IC chips for ADC with high speed (less than 1 μ sec.) and high linearity resolution (more than 10bits) was developed successfully with the best level in the world.These works were performed on the basis on agreement on collaboration between KEK and IHEP.The agreement is continued till October of 2005. Less