共查询到20条相似文献，搜索用时 656 毫秒
1.
杨平 《中国科教创新导刊》2000,(8):16
美国费米国家实验室７月２１日宣布 ,该实验室中来自美国、日本、希腊和韩国的科学家经过３年的合作研究 ,首次发现了表明τ中微子存在的直接证据。至此 ,粒子物理学标准模型中的１２种基本粒子已全部被直接探测到。按照粒子物理学标准模型 ,物质由１２种基本粒子构成 ,它们包括６种夸克 (下夸克、上夸克、奇异夸克、粲夸克、底夸克和顶夸克 )和６种轻子 (电子、电子中微子、μ 子、μ中微子、τ子和τ中微子 )。此前 ,科学家通过实验陆续探测到了除τ子中微子外的其他１１种基本粒子 ,但却一直没有发现τ子中微子存在的直接证据。科学家的… 相似文献
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卢武开 《南宁师范高等专科学校学报》1997,(2)
中微子这种看不见,摸不着的粒子,自从1930年泡利首先提出的概念以来,全世界的实验高能粒子物理学领域的科学家们都在苦苦地追寻它.例如荣获1995诺贝尔物理学奖的美国物理学家弗雷德里克·莱因斯,自1953年起,为了检测到中微子,他和他的同事们进行了三十多年的各种高难度的实验,以探测与中微子有关的效应.最终检测了中微子.为什么中微子有那么大的魅力吸引着科学家们呢.下面就中微子的魅力谈谈个人的看法. 相似文献
3.
1995年10月11日,瑞典皇家科学院宣布,美国加州大学的弗里德里克·莱因斯(F.Reines)因在50年代中期领导一实验小组,捕获到由泡利(W.Pauli)假设并认为“可能永远也探测不到”的粒子——中微子.而与美国斯坦福大学的马丁.佩尔(M.L.Perl)(因发现τ轻子)一起获得了1995年度的诺贝尔物理奖.中微子的发现,起源于人们对β衰变的研究.1930年12月4日,泡利为解决β衰变中的连续谱问题,假设在β衰变中,除了放射电子以外,还伴随着放射一种还不为人知的中性粒子(后由费米(E.Fermi)命名为中微子).随后,费米根据这一假设,建立了著名的β衰变理论.在β衰变中引入中微子,不仅可以解决能量守恒问题,也使动量和角动量得以保持守恒.一种粒子的引入,解决了三大守恒定律的困境,谁不为之动心呢?然而,如何切实地捕捉到中微子呢?却长久地困惑着人们! 相似文献
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《中国科教创新导刊》2005,(3):18
按照粒子物理学标准模型,物质是由12种基本粒子构成的,包括6种夸克和6种轻子。其中轻子包括电子、电子中微子、μ子、μ子中微子、τ子和τ子中微子,当一些轻子发生衰变后会变成别的基本粒子———夸克和中微子。到上个世纪末,科学家们通过各种实验,陆续找到了其中11种基本粒子,但却一直没有发现τ子中微子存在的直接证据。由于τ轻子在放射性物质中发生衰变时不带电,运动中几乎不留下痕迹,又几乎不与周围物质相互作用,所以很难探测到它们。1994年,费米实验室的物理学家布雷南·伦德博格与加州大学的另一位研究人员提出了“τ子中微子直接探… 相似文献
6.
陈颖建 《中国科教创新导刊》1998,(10)
１９９８年６月初,在有２４个国家的３５０余名中微子专家参加的国际会议上,日本东京大学宇宙线研究所的物理学家尾田隆章宣布,超级神冈探测器探测到了μ中微子的振荡现象,这说明中微子具有质量。这一发现在科学界引起了广泛的关注,美国哈佛大学物理学教授,１９７９... 相似文献
7.
孙凯慧 《中学生数理化(高中版)》2004,(12):58-59
2004年江苏高考物理试卷第7题:雷蒙德·戴维思因研究来自太阳的电子中微子(ve)而获得了2002年度的诺贝尔物理学奖.他探测中微子所用的探测器的主体是一个贮满615 t四氯乙烯(C2Cl4)溶液的巨桶. 相似文献
8.
通过类比由爱因斯坦热辐射理论导出黑体辐射公式的方法,文章研究低能中微子辐射理论及辐射特性,进而讨论了低能中微子辐射理论的应用。结论表明,低能中微子在现实生活中非常普遍,最近在建的中微子探测器有能力探测到低能中微子的发射信号。我们预测未来几十年将是中微子研究及应用的黄金时代。 相似文献
9.
中微子是一种非常小的基本粒子,广泛存在于宇宙中,共有电子中微子、μ中微子和τ中微子三种形态,其中只有前两者能被观测到.它可以自由穿过地球,不与任何物质发生作用,因而难以捕捉和探测,被称为宇宙间的"隐身人". 相似文献
10.
《实验室研究与探索》编辑部 《实验室研究与探索》2012,31(12):23-24
今年3月8日大亚湾中微子实验国际合作组发言人、中科院高能物理研究所所长王贻芳在北京宣布,大亚湾中微子实验发现了一种新的中微子振荡(图1),并测量到其振荡几率(图2)。该发现被认为是对物质世界基本规律的一项新的认识, 相似文献
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Suman Beri 《Resonance》2016,21(10):911-924
The 2015 Nobel Prize in Physics was awarded to two physicists-Takaaki Kajita and Arthur B McDonald, whose teams discovered that neutrinos, which come in three flavours, change from one flavour to another. This discovery is a major milestone in particle physics as it gives a clear evidence of physics beyond the Standard Model. Neutrino oscillation is a quantummechanical phenomenon whereby a neutrino created with a specific lepton flavour (electron, muon, or tau) can later be measured to have a different flavour. Historical development of the field in chronological order of experiments is briefly described in this article. 相似文献
13.
Revathi Ananthakrishnan 《Resonance》1999,4(4):12-19
The standard solar model with the standard electroweak theory does not explain the solar neutrino problem. However, a slight modification to this theory, in which there is a mass difference in the neutrinos and mixing between them, does seem to explain the experimental observations. However to test conclusively the theory and oscillation effect, a detector which can detect separately the charged current interactions of the electron neutrinos and neutral current interaction of both the neutrinos with matter and also give accurate measurements of the two interactions is to be built. The next generation of solar neutrino experiments aims to test the above theory. One experiment, which proposes to detect neutrinos through both neutral and charged current interactions, is the Water Cherenkov Detector of the Sudbury Neutrino Observatory (SNO) at Ontario, Canada. Another Water Cherenkov Detector,the massive Super Kamiokande detector, has just become operational and the analysis of the data being collected from the detector are being reported in many conferences. The scientists at Kamiokande have very recently reported at the Neutrino ’98 Conference the exciting result that the neutrino does have a mass. They are now clear that they have reached a level of understanding in Neutrino Astrophysics, where neutrino oscillation solutions can be discussed. 相似文献
14.
张建新 《忻州师范学院学报》2002,18(5):48-50
生物大分子DNA、RNA和氨基酸、蛋白质中普遍存在的由共价键主要是π键构成的苯环状构象,有效地将宇宙背景中低能正、反中微子汇聚,运用上述双光子引力波产生机制,将中微子能转化为光和热,揭示了正物质世界生物大分子左旋结构与反物质世界生物大分子右旋结构稳定性的起源。 相似文献
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基于已知的 Ｄｅ Ｂｒｏｇｌｉｅ模型和 Ｒｏｓｓ模型结合的太阳中微子新模型,可以获得两个中微子合成一个光子及其能量公式。由此能解释太阳中微子的下列三个观察结果;仅检测到理论预测值的三分之一;太阳活动和中微子流间存在反相关关系并与观察到的光子释放率一致。 相似文献
16.
In this part we describe the chain of nuclear reactions that fuse protons into helium nuclei in the centres of stars. Neutrinos
play an important role in the proton-proton chain and detection of these neutrinos is important for a direct insight into
the processes taking place at the centre of the sun. Experiments for the detection of solar neutrinos and the emerging result
from them, known as the Solar Neutrino Puzzle, are described. The puzzle refused to go away even with very carefully designed
experiments. Its solution came from physics, by reviving the idea of neutrino oscillations, speculated many decades ago. Recent
experiments have confirmed these ideas and have enriched our knowledge of these fundamental particles. 相似文献
17.
A historical case study concerning the serious doubts that arose in early 1930s about the validity of the law of energy conservation in nuclear disintegrations, and the hypothesis of neutrino, will be closely analyzed with the goal of promoting understanding of the nature of science. This work is based upon primary archival and printed sources, with a particular focus on the proceedings of the first International Conference of Nuclear Physics which was held in Rome on October 1931. 相似文献
18.
In the concluding part of the article on Neutrinos and our Sun we discuss the detection of atmospheric neutrinos, their fluxes
and zenith angle distributions. Here too one finds discrepancies with theoretical predictions. We discuss how the idea of
neutrino oscillations helps resolve both the solar neutrino puzzle (discussed in Part 2) and the discrepancy observed in atmospheric
neutrino fluxes. This is followed by a discussion of neutrino masses and the recent confirmation of the neutrino oscillations
in the KamLAND experiment. 相似文献
19.
叶子飘 《重庆大学学报(英文版)》2005,4(3):183-184
1 Introduction a In this paper, we calculated the capture rates of pep solar neutrino in the chlorine and gallium solar neutrino experiments according to the standard solar model (SSM)[1-3] in which there are five separate neutrino sources within proton-proton chain involving the following nuclear reactions. 2 p + e ?+ p → H + νe (1) 2 p + p → H + e ++ νe (2) 2 Approximation calculation The rate of the pep reaction, p + e ?+ p → 2 H + νe, can be expressed in terms of the rate of reacti… 相似文献
20.
G Rajasekaran 《Resonance》2005,10(10):49-66
We give an elementary review of recent discoveries in neutrino physics, culminating in the solution of the solar neutrino
problem and the discovery of neutrino mass. Atmospheric neutrinos, reactor neutrinos and other important developments are
also briefly described.
G Rajasekaran is a theoretical physicist at the Institute of Mathematical Sciences, Chennai. His field of research is quantum
field theory and high energy physics. Currently he is working in the area of neutrino physics. 相似文献