A unified theory of electromagnetic and weak interactions proposed separately by Steven Weinberg in 1967 and Abdus Salam in 1968. It is a quantum field theory of renormalizable (non-Abelian) gauge fields that describes the two interactions in a unified manner by introducing two types of charged vector mesons W + and W - and two types of neutral vector mesons as gauge bosons. Neutral mesons mix in a certain ratio to become the massless photon that mediates the electromagnetic interaction with the very heavy meson Z, and Z mesons are considered to mediate the weak interaction together with the charged mesons W + and W - . The three gauge bosons other than the photon acquire mass through the Higgs mechanism. The mass of the W meson was predicted to be 3.8×10 4 /sinθ W MeV (megaelectronvolts), and the mass of the Z meson was predicted to be 7.6×10 4 /sin2θ W MeV. Here, θ W is a quantity that represents the mixing ratio of neutral mesons and is called the Weinberg angle. Analysis of high-energy neutrino experiments gives sin 2 θ W = 0.2315 ± 0.0005. In 1983, W + , W - and Z 0 were discovered at CERN (European Organization for Nuclear Research) with masses exactly as predicted by the theory. Source: Encyclopaedia Britannica Concise Encyclopedia About Encyclopaedia Britannica Concise Encyclopedia Information |
1967年にスティーブン・ワインバーグが,1968年にアブドゥス・サラムが個別に提案した電磁相互作用と弱い相互作用の統一理論。2種類の荷電ベクトル中間子 W+,W-と 2種類の中性ベクトル中間子をゲージボソンとして導入することにより,二つの相互作用を統一的に記述するくりこみ可能な(非可換)ゲージ場の場の量子論。中性中間子は一定の割合で混合して非常に重い中間子 Zと電磁相互作用を媒介するゼロ質量の光子となり,Z中間子は荷電中間子 W+,W-とともに弱い相互作用を媒介するとみなされる。光子以外の 3種のゲージボソンはヒッグス機構により質量を獲得する。W中間子の質量は 3.8×104/sinθWMeV(メガ電子ボルト),Z中間子の質量は 7.6×104/sin2θWMeVと予言された。ただし,θWは中性中間子の混合比を表す量で,ワインバーグ角と呼ばれる。高エネルギーのニュートリノ実験の分析によれば sin2θW=0.2315±0.0005である。1983年ヨーロッパ原子核研究機関 CERNで W+,W-および Z0が理論の予言どおりの質量で発見された。
出典 ブリタニカ国際大百科事典 小項目事典ブリタニカ国際大百科事典 小項目事典について 情報 |
>>: Wainshi (English: Poetry in harmony)
An institution that conducts testing and research...
An Arabic word meaning "things permitted by ...
(1) One of the Seven Warring States of China. Divi...
At the end of the Edo period, this opinion argued ...
Money exchange includes the exchange of various t...
Belief in a god who is a prince (child). It also ...
A general term for gymnastics, equipment gymnasti...
…China’s highest state council in the early Qing ...
A relatively rare perennial plant of the Brassicac...
[What kind of disease is it?] A saddle nose is whe...
...The Omori clan of the Northern House of the Fu...
…However, the nature of pain varies depending on ...
A Russian (Soviet) poet. The son of a blacksmith i...
In December 656, he defeated the combined forces ...
…He used Burt Lancaster, Jack Palance, Eddie Albe...