量子色动力学（QCD）研究什么？
What does quantum chromodynamics (QCD) study?
QCD 是描述强相互作用的量子场论，用“色荷”和胶子说明夸克如何被绑成质子和中子。它还有“渐近自由”：能量越高，强作用力反而越弱。
QCD is the quantum field theory of the strong force; with color charge and gluons it explains how quarks bind into protons and neutrons. It also shows asymptotic freedom: at higher energy the strong force gets weaker.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#量子色动力学 #强相互作用 #渐近自由
世界的基本粒子有哪些？为什么质子和中子不算基本粒子？
What are the fundamental particles of nature, and why aren't protons and neutrons among them?
标准模型把基本粒子分成费米子和玻色子两大类。费米子构成物质，包括6种夸克（上、下、粲、奇、顶、底）和6种轻子（电子、μ子、τ子以及对应的三种中微子）；玻色子传递相互作用，如光子、胶子、W/Z玻色子和希格斯玻色子。质子和中子由夸克组成，所以不是基本粒子；电子没有已知的内部结构，才是真正的基本粒子。
The Standard Model divides elementary particles into fermions and bosons. Fermions make up matter: six quarks (up, down, charm, strange, top, bottom) and six leptons (electron, muon, tau, plus three neutrinos); bosons carry the forces — the photon, gluons, W and Z bosons, and the Higgs. Protons and neutrons are built from quarks, so they are composite; the electron has no known substructure and is genuinely elementary.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
费曼,《费曼物理学讲义》第一至三卷,Addison-Wesley,1963-1965
Richard P. Feynman et al., The Feynman Lectures on Physics, Addison-Wesley, 1963-1965
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-7382-0298-3 (2006 Pearson 版，原始版为1963-65 Addis
#标准模型 #夸克 #轻子
弱相互作用中宇称为什么不守恒？
Why is parity not conserved in the weak interaction?
1956 年李政道与杨振宁指出弱相互作用可能破坏左右对称，吴健雄次年用钴-60 的极化β衰变实验证实宇称确实不守恒。这是首次发现自然界基本相互作用偏爱手性。
In 1956 Lee and Yang proposed that the weak interaction might violate left-right symmetry, and Wu confirmed it the next year with polarized cobalt-60 beta decay. It was the first time a fundamental interaction was found to favor chirality.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
李政道与杨振宁 1956 年论文；吴健雄 1957 年实验
Lee & Yang (1956); Wu experiment (1957)
#宇称不守恒 #弱相互作用 #β衰变
为什么从来没有人观察到单独存在的夸克？
Why has no one ever observed a free, isolated quark?
夸克之间的强相互作用力会随距离增大而增强，就像被一根橡皮筋拉着：你想把两个夸克拉开，就必须注入巨大能量，而这些能量会长出一对新的夸克—反夸克，形成新的粒子。因此夸克只能成团地禁闭在质子、中子等强子内部，永远无法被单独观察到，这就是色禁闭。
The strong force between quarks grows stronger with distance, like being tied by a rubber band: pulling two quarks apart demands enormous energy, and that energy materializes as a new quark-antiquark pair, forming new particles. So quarks are permanently confined inside hadrons such as protons and neutrons and can never be seen alone — color confinement.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#色禁闭 #夸克 #强相互作用
中微子为什么能轻松穿过整个地球？
Why can a neutrino pass straight through the whole Earth?
中微子只参与弱相互作用和引力，几乎不与物质碰撞，截面极小。每秒有万亿计的中微子穿过你身体而毫无感觉，大多来自太阳核聚变。
Neutrinos feel only the weak force and gravity, so they almost never hit matter—their cross-section is tiny. Trillions pass through you each second, mostly from the Sun's fusion, unnoticed.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#中微子 #弱相互作用 #太阳
希格斯玻色子是怎么给基本粒子「赋予质量」的？
How does the Higgs boson 'give mass' to elementary particles?
根据电弱统一理论，真空里充满希格斯场；有质量的粒子（如 W/Z 玻色子、夸克、轻子）与这个场耦合，运动时就受到「拖拽」而表现为惯性质量，耦合越强质量越大，而无质量的光子不与它耦合。希格斯玻色子是这个场的量子激发。2012年 ATLAS 与 CMS 在 LHC 上发现它， Englert 与 Higgs 获2013年诺贝尔奖。
In electroweak theory the vacuum is filled with the Higgs field; massive particles (W/Z bosons, quarks, leptons) couple to it and feel 'drag' that shows up as inertial mass—stronger coupling means more mass—while the massless photon does not couple. The Higgs boson is the field's quantum excitation. ATLAS and CMS discovered it at the LHC in 2012; Englert and Higgs won the 2013 Nobel Prize.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#希格斯机制 #对称性破缺 #电弱统一
四种基本力里的弱相互作用到底干什么用？
What does the weak interaction, one of the four fundamental forces, actually do?
弱相互作用作用距离极短，专门负责改变夸克的味道，比如中子衰变成质子、电子和反中微子（β衰变）就靠它。太阳聚变的第一步——两个质子融合成氘——也必须通过弱相互作用，这一步慢得惊人，正因为如此，太阳才像文火慢炖一样稳定燃烧了几十亿年，而不是瞬间炸光。
The weak interaction acts only over tiny distances and changes the flavor of quarks: a neutron decaying into a proton, electron, and antineutrino (beta decay) is its work. The first step of solar fusion, two protons fusing into deuterium, also needs the weak force, and it is so excruciatingly slow that the Sun burns steadily for billions of years instead of exploding all at once.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 2 条独立证据
来源 · Source
《费曼物理学讲义》第一卷（弱相互作用）
The Feynman Lectures on Physics, Vol. 1 (the weak interaction)
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-7382-0298-3 (2006 Pearson 版，原始版为1963-65 Addis
#弱相互作用 #β衰变 #太阳聚变
CP破坏在粒子物理与宇宙学中为何重要，它在标准模型中如何出现？
Why is CP violation important in particle physics and cosmology, and how does it appear in the Standard Model?
CP破坏使物质与反物质演化不对称，是解释宇宙中物质占优所需的条件之一。标准模型中它源于夸克混合矩阵（CKM矩阵）的不可约复相位，在 K 与 B 介子系统中已被实验观测到。
CP violation makes matter and antimatter evolve asymmetrically and is one of the conditions needed to explain the matter dominance of the universe. In the Standard Model it arises from the irreducible complex phase of the quark mixing (CKM) matrix, observed in K and B meson systems.
难度 专业 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Christenson, Cronin, Fitch & Turlay, Phys. Rev. Lett. 13, 138 (1964)（K⁰_L→2π的CP破坏）
J. H. Christenson, J. W. Cronin, V. L. Fitch & R. Turlay, Phys. Rev. Lett. 13, 138 (1964) (CP violation in K_L→2π)
#CP破坏 #CKM矩阵 #物质反物质不对称 #宇称
自然界有哪四种基本相互作用，强弱各如何？
What are the four fundamental forces, and how do their strengths compare?
强相互作用、弱相互作用、电磁力和引力。强相互作用束缚原子核、最强；电磁力管原子与光；弱相互作用管放射性衰变；引力最弱却作用最远，决定天体运动。
They are the strong and weak nuclear forces, electromagnetism, and gravity. The strong force binds nuclei and is strongest; electromagnetism runs atoms and light; the weak force drives radioactive decay; gravity is weakest but reaches farthest, ruling the cosmos.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
Weinberg，《量子场论》（第一卷）
Weinberg, 'The Quantum Theory of Fields' (Vol. I)
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL3398955W：The Quantum Theory of F
#基本力 #强相互作用 #引力
中微子振荡现象说明了中微子的哪一条基本性质，并如何推翻「中微子无质量」的旧假设？
What fundamental property does neutrino oscillation reveal, and how does it overturn the old assumption of massless neutrinos?
中微子振荡指一种味本征态（如电子中微子）在传播中转化为另一种味的概率性现象，只能在质量本征态与味本征态不同且中微子具有非零质量差时才发生。该现象证明至少两种中微子有质量，从而修正了标准模型中无质量中微子的设定。
Neutrino oscillation is the probabilistic conversion of one flavor eigenstate (e.g., electron neutrino) into another during propagation, which occurs only when flavor and mass eigenstates differ and neutrinos have non-zero mass-squared differences. It proves at least two neutrino species are massive, revising the massless-neutrino assumption in the Standard Model.
难度 专业 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Fukuda et al.（Super-Kamiokande）, Phys. Rev. Lett. 81, 1562 (1998)（大气中微子振荡证据）
Super-Kamiokande Collaboration, Phys. Rev. Lett. 81, 1562 (1998) (evidence for atmospheric neutrino oscillation)
#中微子振荡 #味本征态 #质量本征态 #味混合
希格斯玻色子为什么那么重要？它和质量有什么关系？
Why is the Higgs boson so important, and what does it have to do with mass?
希格斯玻色子是2012年在CERN的大型强子对撞机上发现的。根据希格斯机制，宇宙中充满希格斯场，不同基本粒子与它相互作用的强弱不同，因而获得不同的质量；光子不参与这种作用，所以静质量为零。希格斯玻色子正是希格斯场的量子激发，它自身也有质量。没有它，电子和夸克都会以光速飞行，原子和恒星都无法形成。
The Higgs boson was discovered at CERN's Large Hadron Collider in 2012. In the Higgs mechanism, a field permeates all space, and particles acquire different masses by interacting with it more or less strongly; the photon doesn't interact and stays massless. The Higgs boson is the quantum excitation of that field and has mass itself. Without it, electrons and quarks would fly at light speed and atoms and stars could never form.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#希格斯玻色子 #希格斯场 #质量起源
强相互作用的“渐近自由”是什么意思？
What does 'asymptotic freedom' of the strong interaction mean?
量子色动力学（QCD）预言，夸克之间距离越近、能量越高，强耦合常数越小，于是表现得几乎自由；距离拉开时耦合反而变强，导致色禁闭。Gross、Politzer 与 Wilczek 于 1973 年算出这一性质并获 2004 年诺奖。
Quantum chromodynamics predicts that the strong coupling grows weak at very short distance and high energy, so quarks act nearly free—asymptotic freedom—while it strengthens at larger distance, causing color confinement. Gross, Politzer and Wilczek computed this in 1973 (Nobel 2004).
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
Gross、Politzer、Wilczek 1973 年论文；《物理评论快报》
Gross, Politzer & Wilczek (1973); Physical Review Letters
#渐近自由 #量子色动力学 #色禁闭
中微子有质量吗？
Do neutrinos have mass?
标准模型最初假设中微子无质量，但 Super-Kamiokande 等实验在 1998 年观测到中微子振荡——即不同味之间互相转变，而振荡只有在粒子有质量时才可能。2015 年诺贝尔物理学奖授予了这一发现者。
The original Standard Model assumed massless neutrinos, but Super-Kamiokande and others observed neutrino oscillations in 1998—flavors converting into one another, possible only if they have mass. The 2015 Nobel Prize honored this discovery.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：著录含书名，但缺版次 / 出版社 / 年份中的一部分，需编辑补全后才能做独立比对。
Super-Kamiokande 实验（梶田隆章、麦克唐纳，2015 诺奖）；《物理评论快报》
Super-Kamiokande (Kajita & McDonald, Nobel 2015); Physical Review Letters
#中微子 #中微子振荡 #味转变
希格斯机制如何在不破坏整体规范不变性的前提下，赋予 W、Z 玻色子质量？
How does the Higgs mechanism give mass to the W and Z bosons without breaking overall gauge invariance?
希格斯场在电弱对称破缺中取得非零真空期望值，其与规范场的耦合项转化为规范玻色子的质量项，而拉格朗日量整体仍规范不变。W± 与 Z 玻色子由此获得质量，光子保持无质量，这一机制于2012年由CMS与ATLAS实验发现希格斯玻色子证实。
The Higgs field acquires a non-zero vacuum expectation value in electroweak symmetry breaking, and its coupling to gauge fields becomes a mass term for the gauge bosons while the full Lagrangian remains gauge invariant. The W± and Z bosons gain mass while the photon stays massless; the mechanism was confirmed by the 2012 CMS and ATLAS discovery of the Higgs boson.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-04 · 2 条独立证据
来源 · Source
Higgs, Phys. Rev. Lett. 13, 508 (1964)；Englert & Brout, Phys. Rev. Lett. 13, 321 (1964)；ATLAS Collaboration, Phys. Lett. B 716, 1 (2012)；CMS Collaboration, Phys. Lett. B 716, 30 (2012)
P. W. Higgs, Phys. Rev. Lett. 13, 508 (1964); Englert & Brout, Phys. Rev. Lett. 13, 321 (1964); ATLAS Collab., Phys. Lett. B 716, 1 (2012); CMS Collab., Phys. Lett. B 716, 30 (2012)
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1103/physrevlett.13.508（复合著录按段核验：本标识只担保第 · 核验依据 2 Crossref DOI 10.1103/physrevlett.13.321（复合著录按段核验：本标识只担保第
#希格斯机制 #电弱对称破缺 #规范玻色子 #真空期望值
量子色动力学中的「色禁闭」为何使我们无法观测到自由夸克？
Why does color confinement in quantum chromodynamics prevent us from observing free quarks?
QCD中耦合常数随距离增大（红外奴役），拉开夸克需注入的能量会在真空中产生新的夸克-反夸克对，故能量用于产生介子而非分离单个夸克。因此色荷被禁闭在强子内部，只能观测到无色的强子。
In QCD the coupling grows with distance (infrared slavery); pulling quarks apart injects energy that creates new quark-antiquark pairs from the vacuum, so the energy goes into making mesons rather than isolating a quark. Color charge is therefore confined inside colorless hadrons and only hadrons are observable.
难度 专业 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Wilson,《Confinement of quarks》,Physical Review D,1974 (DOI: 10.1103/physrevd.10.2445)
K. G. Wilson, 'Confinement of quarks', Physical Review D, 1974, DOI: 10.1103/physrevd.10.2445
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1103/physrevd.10.2445
#量子色动力学 #色禁闭 #红外奴役 #强子
强聚焦同步加速器里，单个四极磁铁在一个平面聚束、在另一平面散焦，为什么交替排列反而能让束流在两个横向都被束缚住？
A single quadrupole focuses one transverse plane while defocusing the other—why does alternating their gradients nevertheless confine the beam in both planes of a strong-focusing synchrotron?
沿束线逐个翻转四极磁铁极性后，每个粒子在任一平面都经历聚焦—散焦交替序列。Courant-Snyder传输矩阵分析表明，只要每单元相位推进选取合适，单元映射矩阵迹的绝对值小于2，轨道保持有界，束流包络稳定。这一1952年提出的方案把同步加速器所需孔径从米量级压缩到厘米量级，是现代环形机器的基石。
With quadrupole polarities flipped cell by cell along the ring, every particle experiences an alternating focus-defocus sequence in either plane. Courant-Snyder transfer-matrix analysis shows that for suitable phase advance the one-cell map has |Tr M| < 2, keeping orbits bounded and the beam envelope stable. Proposed in 1952, the scheme shrank required synchrotron apertures from meters to centimeters and underpins every modern ring.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Courant、Livingston 与 Snyder,《The Strong-Focusing Synchroton—A New High Energy Accelerator》,Physical Review,1952 (DOI: 10.1103/physrev.88.1190)
Courant, Livingston & Snyder, 'The Strong-Focusing Synchroton—A New High Energy Accelerator', Physical Review, 1952, DOI: 10.1103/physrev.88.1190
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1103/physrev.88.1190
#四极磁铁 #束流光学
质子在环里跑了几十万圈,加速器怎么保证它们不散架也不撞墙?
Protons lap the ring hundreds of thousands of times — how does the machine keep them focused and off the walls?
靠射频腔与磁铁格点组成的精密节拍。加速:直线段里的射频腔以400兆赫振荡,相位被精确锁定,质子每次经过都赶上加速半波,反复累积能量;电场同时把能量略有差异的粒子压缩成紧密束团。约束与聚焦:偶极磁铁负责转弯,真正防散架的是四极磁铁——它在水平方向聚焦、垂直方向散焦,交替排列后净效果如同透镜组,任何偏离都被周期性拉回。整套晶格设计须保证横向偏差沿环振荡而不放大,这由加速器光学中的希尔方程及其稳定性条件决定。
A precise rhythm of RF cavities and magnetic lattice elements does it. Acceleration: radiofrequency cavities oscillating at 400 MHz keep their phase locked so each proton pass arrives on the accelerating half-wave, bundling particles of slightly different energy into tight bunches. Confinement: dipoles bend, but quadrupoles are the guardians — focusing horizontally while defocusing vertically, arranged alternately so the net effect acts like a lens channel pulling deviations back periodically. The whole lattice must make errors damp rather than grow, governed by the Hill equations of accelerator optics.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-10-04 · 2 条独立证据
来源 · Source
Wiedemann,《Particle Accelerator Physics》第3版,Springer,2007
H. Wiedemann, Particle Accelerator Physics, 3rd ed., Springer, 2007
独立核验依据 · Independent verification: 核验依据 1 ISBN 9783319183176 (2007) · 核验依据 2 ISBN 9789810237097 (2004)
#射频加速 #四极磁铁 #束流聚焦
粒子物理标准模型由哪几类基本粒子构成，它们通过哪几种基本相互作用联系？
What classes of elementary particles make up the Standard Model, and through which fundamental interactions are they connected?
标准模型包含三代夸克与轻子共12种费米子、传递相互作用的规范玻色子（光子、W/Z、胶子）以及赋予质量的希格斯玻色子。它们通过强、弱、电磁三种相互作用联系，引力尚未纳入标准模型框架。
The Standard Model comprises 12 fermions in three generations of quarks and leptons, the gauge bosons (photon, W/Z, gluons) that mediate interactions, and the mass-giving Higgs boson. They interact via the strong, weak, and electromagnetic forces; gravity is not yet included.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-05 · 4 条独立证据
来源 · Source
粒子数据组（Particle Data Group），《粒子物理学评论》，Progress of Theoretical and Experimental Physics (2022)
Particle Data Group, 'Review of Particle Physics', Progress of Theoretical and Experimental Physics (2022)
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL44253297W：Review of particle phy · 核验依据 3 ARCHIVE 标识 Review_of_Particle_Physics：Review of Particle
#标准模型 #夸克 #轻子 #规范玻色子
粒子物理的「标准模型」把基本粒子分成了哪几类？
How does the particle-physics 'Standard Model' classify the fundamental particles?
标准模型把物质的基本组分分为夸克（上、下、奇、粲、底、顶）和轻子（电子、μ子、τ子及其对应中微子），它们通过传播子传递的三种相互作用相互联系：光子管电磁力、W/Z 玻色子管弱力、胶子管强力，再加上赋予质量的希格斯玻色子。引力尚未纳入其中。粒子数据组（PDG）每年发布权威的粒子清单与参数。
The Standard Model divides matter's building blocks into quarks (up, down, strange, charm, bottom, top) and leptons (electron, muon, tau and their neutrinos), interacting via three forces carried by bosons: photons for electromagnetism, W/Z for the weak force, gluons for the strong force, plus the mass-giving Higgs boson. Gravity is not yet included. The Particle Data Group publishes the authoritative annual particle listing.
难度 进阶 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-11-03
来源 · Source
粒子数据组（PDG）《粒子物理学评论》标准模型总结表
Particle Data Group (PDG), 'Review of Particle Physics', Standard Model summary tables
独立核验依据 · Independent verification: 核验依据 1 OPENLIBRARY 标识 /works/OL44253297W：Review of particle phy
#标准模型 #夸克 #基本相互作用
β衰变过程中弱相互作用如何改变夸克味，并伴随哪些粒子产生？
In beta decay, how does the weak interaction change quark flavor, and which particles are emitted?
β⁻衰变中，中子内的下夸克经弱相互作用转为上夸克，同时放出电子与电子反中微子，由 W⁻ 玻色子作为媒介。这本质上是味改变的过程，并违反宇称守恒，是弱力的典型表现。
In beta-minus decay a down quark inside a neutron turns into an up quark via the weak interaction, emitting an electron and an electron antineutrino mediated by a W⁻ boson. This flavor-changing process violates parity conservation and is a hallmark of the weak force.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Fermi, Z. Phys. 88, 161 (1934)（β衰变理论）；Wu, C.S. et al.,《Experimental Test of Parity Conservation in Beta Decay》, Physical Review, 1957 (DOI: 10.1103/physrev.105.1413)
E. Fermi, Z. Phys. 88, 161 (1934) (theory of beta decay); Wu et al., 'Experimental Test of Parity Conservation in Beta Decay', Physical Review, 1957, DOI: 10.1103/physrev.105.1413
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1103/physrev.105.1413
#β衰变 #弱相互作用 #味改变 #W玻色子
大型强子对撞机（LHC）通过何种方式寻找新粒子，其探测希格斯玻色子的依据是什么？
How does the Large Hadron Collider search for new particles, and on what basis did it detect the Higgs boson?
LHC将质子加速至近光速并使其对撞，产生极高能标下的末态粒子，由 ATLAS 与 CMS 等探测器重建产物。希格斯玻色子寿命极短，通过其衰变到双光子、ZZ* 等可观测末态的超出本底信号被间接确认。
The LHC accelerates protons to near light speed and collides them, producing final-state particles at very high energies that detectors such as ATLAS and CMS reconstruct. The short-lived Higgs boson was identified indirectly through excess signals in observable decay channels like two photons and ZZ*.
难度 进阶 · 适合 大众
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
ATLAS Collaboration, Phys. Lett. B 716, 1 (2012)；CMS Collaboration, Phys. Lett. B 716, 30 (2012)（125 GeV玻色子发现）
ATLAS Collab., Phys. Lett. B 716, 1 (2012); CMS Collab., Phys. Lett. B 716, 30 (2012) (discovery of a 125 GeV boson)
#大型强子对撞机 #对撞机物理 #ATLAS #CMS #希格斯
顶夸克为何特殊，它的质量为何与希格斯场真空期望值处于同一量级？
Why is the top quark special, and why is its mass of the same order as the Higgs vacuum expectation value?
顶夸克是标准模型中最重的费米子（约173 GeV），其汤川耦合接近1，衰变前几乎不与强子化。它与希格斯场极强的耦合被视为研究电弱对称破缺与潜在新物理的敏感探针。
The top quark is the heaviest Standard Model fermion (about 173 GeV), with a Yukawa coupling near unity, and it decays before hadronizing. Its exceptionally strong coupling to the Higgs field makes it a sensitive probe of electroweak symmetry breaking and possible new physics.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
CDF & D0 Collaborations, Phys. Rev. Lett. 74, 2626 (1995)（顶夸克发现）
CDF and D0 Collaborations, Phys. Rev. Lett. 74, 2626 (1995) (top quark discovery)
#顶夸克 #汤川耦合 #费米子质量 #电弱对称破缺
中微子为什么被称为幽灵粒子？它真的存在吗？
Why are neutrinos called ghost particles, and are they real?
中微子极轻、不带电，几乎不与任何物质相互作用，每秒有上万亿个中微子穿过你的身体而你毫无感觉，所以叫幽灵粒子。但它们的的确确存在：太阳和核反应堆都在大量产生中微子，深地探测器用巨型容器捕捉到极其稀少的中微子事件。发现中微子振荡的实验还获得了2015年诺贝尔物理学奖。
Neutrinos are ultralight and chargeless, barely interacting with anything; trillions pass through your body every second unnoticed, hence the ghost-particle nickname. They are absolutely real: the Sun and nuclear reactors produce floods of them, and huge underground detectors catch the rare interactions. Experiments revealing neutrino oscillations won the 2015 Nobel Prize in Physics.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#中微子 #振荡 #探测器
粒子对撞机怎么“看见”比原子还小的世界？
How does a particle collider see a world smaller than atoms?
它把粒子加速到极高能量对撞，根据德布罗意波长，能量越高能分辨的尺度越小。碰撞碎屑被探测器记录，再反推出了哪些粒子。
It accelerates particles to huge energies and smashes them together; by de Broglie's wavelength, higher energy resolves smaller scales. Detectors record the debris and reconstruct which particles appeared.
难度 进阶 · 适合 小学高段(9-12)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#对撞机 #高能 #探测器
科学家为什么把粒子加速到接近光速再对撞？能撞出什么？
Why do scientists smash particles together at nearly the speed of light, and what can come out?
因为E=mc²，对撞能量可以转化为新粒子的质量：能量越高，越可能撞出更重的新粒子，再现宇宙大爆炸后一瞬间的极端状态。CERN的大型强子对撞机让质子束以接近光速对撞，周围的巨型探测器记录碰撞碎片，物理学家从中寻找新粒子、检验理论。希格斯玻色子就是这样被发现的。
Thanks to E=mc², collision energy can turn into the mass of new particles: the higher the energy, the heavier the particles you might create, recreating conditions from the first instants after the Big Bang. CERN's Large Hadron Collider smashes proton beams at nearly light speed while giant detectors record the debris, letting physicists hunt for new particles and test theories. That is how the Higgs boson was found.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#大型强子对撞机 #对撞 #新粒子
质子和中子是由什么组成的？
What are protons and neutrons made of?
它们是由三个夸克组成的强子：质子是 uud、中子是 udd。夸克被胶子用强作用力绑在一起，且永不单独出现（色禁闭）。
They are hadrons of three quarks each: the proton is uud, the neutron udd. Gluons bind quarks by the strong force, and quarks never appear alone (color confinement).
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#夸克 #强子 #质子
同步加速器为什么不采用一次到位的直流高压，而要让粒子束一圈圈地穿过梯度仅数兆伏的射频腔来积累能量？
Why does a synchrotron accumulate energy by passing the beam through radio-frequency cavities of only a few megavolts every turn, rather than applying one large DC voltage?
直流间隙上的电压受绝缘击穿限制，能量增益存在硬上限；射频腔把电场束缚在谐振结构内，能在很小的间隙上维持高梯度并被反复复用。粒子每圈获得固定的能量增量，射频相位还会自动对偏离同步的粒子施加纵向聚焦，使束团保持紧凑。弯转磁铁同步提升磁场以锁定轨道半径，二者配合即可把最终能量推到任何单一直流方案都无法企及的水平。
A DC gap is capped by insulation and electrical breakdown, whereas resonant cavities confine the accelerating field within a structure that sustains high gradients and is reused turn after turn. Each revolution deposits a fixed energy increment, and the RF phase provides automatic longitudinal focusing that keeps off-momentum particles bunched around the synchronous particle. Bending magnets ramp up in step to hold the orbit radius fixed, together pushing the final energy far beyond any single-voltage scheme.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-10-04
来源 · Source
S. Y. Lee 所著《Accelerator Physics》第4版，World Scientific
S. Y. Lee, Accelerator Physics, 4th ed., World Scientific
独立核验依据 · Independent verification: 核验依据 1 ISBN 9789810237097 (2004)
#射频加速 #纵向动力学
大型强子对撞机的隧道为什么要挖27公里长?小一圈不行吗?
Why did the Large Hadron Collider need a 27 km tunnel — wouldn't something smaller do?
两个硬约束决定周长。其一,要提高对撞能量,要么增强磁场要么加大半径:同样的超导磁体强度下,弯曲半径越大,可达束流能量与周长成正比,27公里的隧道让8.33特斯拉磁体把每束质子推到7万亿电子伏。其二,带电粒子近光速绕圈时会沿切向辐射电磁波损失能量(同步辐射),转得越急损耗越大,轻子机器尤其吃亏;质子质量大得多,同样情形下这类损耗低许多个量级,但加大半径仍能明显省下这部分功率。隧道直接沿用LEP旧隧,也是经济账的一部分。
Two hard constraints set the circumference. Energy: at fixed magnet strength, attainable beam energy scales with bending radius — the 27 km ring lets 8.33 tesla superconducting magnets push each proton beam to seven trillion electronvolts. Losses: charged particles circling near light speed radiate electromagnetic waves along their tangent (synchrotron radiation), and tighter turns waste more; electrons suffer most, while protons, being thousands of times heavier, lose orders of magnitude less — though a larger radius still trims this loss. Reusing the LEP tunnel also made the economics work.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-11-04
来源 · Source
Evans 与 Bryant,《LHC Machine》,Journal of Instrumentation,2008 (DOI: 10.1088/1748-0221/3/08/s08001)
Evans & Bryant, 'LHC Machine', Journal of Instrumentation, 2008, DOI: 10.1088/1748-0221/3/08/s08001
独立核验依据 · Independent verification: 核验依据 1 Crossref DOI 10.1088/1748-0221/3/08/s08001
#对撞机 #同步辐射 #超导磁体
「反物质」是什么，遇到普通物质会发生什么？
What is antimatter, and what happens when it meets ordinary matter?
每种粒子都有对应的反粒子：电荷等量子数相反、质量相同，比如正电子是电子的反粒子。当粒子与反粒子相遇时，两者一起湮灭，质量按 E=mc² 全部转化为能量（通常是高能光子）。安德森1932年在宇宙线中发现正电子，是反物质存在的首个证据；今天大型强子对撞机也能制造反质子等。
Every particle has an antiparticle with opposite charge and same mass—e.g., the positron is the electron's antiparticle. When a particle meets its antiparticle they annihilate, converting their mass entirely to energy (usually high-energy photons) per E=mc². Anderson discovered the positron in cosmic rays in 1932, the first evidence of antimatter; the LHC now makes antiprotons too.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
曾谨言,《量子力学 卷I》,科学出版社,2013
Zeng Jinyan, Quantum Mechanics Vol.I, Science Press, 2013
独立核验依据 · Independent verification: 核验依据 2 DOUBAN ISBN 标识 9787030387226（按标识回读: 量子力学 卷1）
#反物质 #湮灭 #正电子