继续探索失踪的中微子

继续探索失踪的中微子长期以来使我们困惑不解的太阳中微子“失踪”之谜仍未揭开。从新近太阳中微子实验获得的最新研究结果使物理学家依然无法肯定，是我们对太阳内部的认识有误，还是我们对中微子认识本身就有错误。自从戴维斯在美国南达科他州霍姆斯特克金矿全氯乙烯容...     

太阳中微子失踪之谜

太阳中微子失踪之谜弄清太阳自身演化及其能量产生规律对人类生存具有至关重要的意义，而太阳中微子的数量是一个重要信息。科学家在地球上探测到的中微子数目还不到理论预言的一半。那么，其余的太阳中微子到何处去了呢？几十年来，天体物理学家一直被这个问题所困扰。我...     

中微子介绍

2012年3月8日,以中国为主导的大亚湾中微子实验国际合作组对外宣布,发现新的中微子振荡(θ13),并测量到其振荡几率sin22θ13为0.092.这一重要成果是对物质世界基本规律的一项新的认识,或有助于破解"反物质之谜".鉴于这一结果将对中微子物理未来的发展起决定性作用,大量中外媒体对此事件进行了报道和评论.中微子是近年来物理研究的一个热点.近20多年来,世界上有6     

科学家证实太阳中微子有质量

由东京大学宇宙线研究所等组成的一个联合研究组最近证实，来自太阳的中微子有质量．这一成果有可能推翻迄今认为中微子质量是“0”的微粒子物理学理论．     

“幽灵粒子”:超越粒子物理标准模型

<正>1930年,奥地利物理学家泡利预言,宇宙中可能存在一种"永远找不到"的粒子。它呈电中性,且质量很小,运动速度接近光速,泡利将它命名为"中微子"。从预言开始,中微子就蒙着一层神秘的面纱,科学家将这种几乎不与其他物质发生相互作用的粒子戏称为"幽灵粒子"。中微子的"任性"和"高冷"引起不少科学家的极大兴趣,他们将其视为物质世界的"bug",或许通过它能够探寻尚未揭开的自然之谜。     

与2002年诺贝尔物理学奖相关的综合题

瑞典皇家科学院 2 0 0 2年 1 0月 8日宣布 ,将 2 0 0 2年诺贝尔物理学奖授予美国科学家戴维斯、贾科尼和日本科学家小柴昌俊 ,以表彰他们在天体物理学领域的贡献 .该奖表彰了两项成果 ,一项是在探测宇宙中微子方面取得的成就 ,另一项是发现了宇宙Ｘ射线源 ,这两方面的成就导致了中微子天文学、Ｘ射线天文学的诞生 .结合以上材料回答下列问题 :1 .太阳是一个巨大的中微子源 ,太阳内部进行着剧烈的轻核聚变 ,每4个氢核结合成 1个氦核 ,放出两个正电子和两个中微子 (ν) ,写出上述核反应方程式 .2 .读下表 :太阳中微子的能谱和流量源反应简称 …     

中微子与泡利

在众多的亚原子粒子家族中,中微子是最令人捉摸不定的基本态粒子。它们虽然只参与弱相互作用,但它们似乎具有许多独特的性质,它们与粒子物理和天体物理的基本理论有着广泛的和至关重要的联系。泡利是第一个预言中微子存在的理论物理学家,他有着和中微子一样的迷,既琢磨不透,又魅力无穷。     

中微子是粒子世界中的一个神秘成员——评湖南教育出版社出版的《中微子之谜》

孙汉城教授编写的《中微子之谜》是一本非常好的小册子。 这是《科学家谈物理》丛书中的一本。这套丛书主要约请在各个领域中颇有研究经验的科学家,用深入浅出的笔墨撰写,是介绍物理学各个方面的基础知识     

揭开中微子的神秘面纱

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.     

一道很容易出现问题的小题

原理：物理学家们普遍相信太阳发光是由于其内部不断发生从氢核到氦核的聚变反应．根据这一理论，在太阳内部每四个氢核（ep质子）转化成一个氦核（^4 2He）和2个正电子（^0 1e）及两个神秘的中微子（Ve），在基本粒子物理学的标准模型中中微子是没有质量的．     

Hans Bethe, the sun and the neutrinos

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.     

Neutrinos and our Sun — Part 3

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.     

中微子在致密等离子体中的传播

1　Introduction　Howasupernovaexplodesisstillanunsolvedprob lemrelatingcriticallytothetransportofneutrinoswithinthestar.TheneutrinoheatingmechanismhasbeenaresearchfocusfortypeⅡsupernovaexplosionsinceitwaspresentedbyWilsonin 1982 [1,2 ] .Accord ingtotheircalculationtheoutgoingshockdoesnothaveenoughenergytoejecttheouterlayersofthesu pernova .Theshockwavestallsafterpropagating 10 0～ 30 0kmfromthecore .Immenselyhighenergyflux esofneutrinos (Lνe≈Lνe≈ 4× 10 52 ergs/s ,withνμ,νμ,νT,and…     

Neutrinos and our sun — Part 2

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.     

De Broglie-Ross模型和太阳中微子问题

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。     

低能中微子的产生机制及应用

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。     

Solar neutrinos

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.     

冷核聚变新途径的探讨

作者通过讨论β衰变以及中微子性质、弱相互作用过程中遵循的诸守恒定律,从理论上说明可以利用中徽子和反中徽子促使质子和中子互相转化,从而实现提高冷核聚变反应速率     

Effect of solar electron temperature on pep solar neutrino flux in the chlorine solar neutrino experiment and the gallium solar neutrino experiment

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…     

Neutrinos and our Sun — Part 1

The elusive neutrinos have periodically yielded their secrets to man and at each such juncture major advances have been achieved in our understanding of the sub-atomic phenomena. These particles also carry invaluable information about the centre of the Sun where energy is generated through nuclear fusion. In Part I of this article, history of the discovery of neutrinos is traced, their properties and types are described. Also, the Standard Model which forms the basis of the structure of matter and of which massless neutrinos are an integral part, is described. The role of neutrinos in solar energy generation and the great ‘solar neutrino puzzle’ and its solution will be described later in the series.