OBSERVATION OF HIGH-ENERGY NEUTRINO REACTIONS AND EXISTENCE OF 2 KINDS OF NEUTRINOS
OBSERVATION OF HIGH-ENERGY NEUTRINO REACTIONS AND EXISTENCE OF 2 KINDS OF NEUTRINOS
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DOI：
10.1103/physrevlett.9.36
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发表时间：
1962-01-01
影响因子：
8.6
通讯作者：
SCHWARTZ, M
中科院分区：
文献类型：
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作者：
DANBY, G;LEDERMAN, LM;SCHWARTZ, M
图2 (c)显示了具有K '的事件的“缺失质量”谱，这是唯一可见的碰撞产物。相空间KN区域的事件必须校正K、K、n和K a、~ K z末态的污染。这在1时很容易做到。89 BeV/c，因为所有这些反应都已经在之前的实验中研究过了。结果显示，有（17+ 8）K,'K,'n个事件和（15+ 7）K K'p个事件，比较有利。Y与1介子交换模型要求的相同数量。假设单介子交换模型是有效的，人们可以对KK系统的角动量施加相当严格的限制。由于wv系统的G宇称是偶的，我们有“G=(-1)=+ 1”，其中I是KK系统的角动量，I是同位素自旋。图2 (a)中的数据显示了vm KK -2 mb在I= 0、I= 0 K对和0时的低能截面。对于I= 1,1，为6mb。= 1k对。当能量超过KK系统的阈值100 MeV或更高时，两个截面都降至低值。本实验中观察到的8例K+ K生成[反应(3)j]未包括在上述分析中。这些事件的特征是带电K+衰变，这对K动量谱很敏感。由于难以将这些事件与Z+衰变区分开来，可能会产生额外的偏差。在我们的
Figure 2 (c) shows the" missing mass" spectrum for events which have a K,'as the only visible collision product. The events in the KN region of phase space must be corrected for contamination from K,'K,'n, &'K'A',~'K'Z final states. This was easily done at 1. 89 BeV/c since all these reactions have been studied in a previous experi-ment at that momentum. The result shows there were (17+ 8) K,'K,'n events and (15+ 7) K K'p events, which compares favorabl. y with the equal number called for by the one-pion-exchange model. Provided the one-pion-exchange model is valid, one may place rather strict limits on the angular momentum of the KK system. Since the G parity of the wv system is even, we have" G=(-1)=+ 1, where I is the angular momentum of the KK system and I is the isotopic spin. The data in Fig. 2 (a) then suggest the low-energy cross section for vm KK is-2 mb for I= 0, I= 0 K pairs and-0. 6 mb for I= 1, 1.= 1 K pairs. Both cross sections drop to low values for energies of 100 MeV or more above threshold for the KK sys-tem.Eight examples of K+ K production [reaction (3) j observed in this experiment were not included in the foregoing analysis. The signature of these events is a charged K+ decay, which is sensitive to the K momentum spectrum. Additional bias may result from the difficulty in distinguishing some of these events from Z+ decays. In our