The Elementary Nature of Fundamental Particles

“gauge” invariance

QED, Quantum Electro-Dynamics

“the Standard Model” of particle interactions (SM)

<p>the gravitational force</p> Signup and view all the answers

<p>the theory of general relativity</p> Signup and view all the answers

<p>string theory</p> Signup and view all the answers

<p>The three classes of fundamental interactions at the microscopic level are strong, electromagnetic, and weak interactions.</p> Signup and view all the answers

<p>Electromagnetic forces bind the electrons to nuclei in atoms.</p> Signup and view all the answers

<p>Light is a particular vibration of electric and magnetic fields, also known as an electromagnetic wave.</p> Signup and view all the answers

<p>Strong interactions bind protons and neutrons together in nuclei.</p> Signup and view all the answers

<p>Protons and neutrons are composed of three quarks held together by strong interactions.</p> Signup and view all the answers

<p>The weak interactions are responsible for beta radioactivity, nuclear reactions in stars, and the decay of certain particles.</p> Signup and view all the answers

<p>quarks and leptons</p> Signup and view all the answers

<p>+2/3 and -1/3 respectively</p> Signup and view all the answers

<p>-1 and 0 respectively</p> Signup and view all the answers

<p>3</p> Signup and view all the answers

<p>asymptotic freedom and confinement</p> Signup and view all the answers

<p>$\alpha_s = \frac{e_s^2}{4\pi}$</p> Signup and view all the answers

<p>The basis for the relation between high energy physics and cosmology is the ever increasing relation between high energy physics and cosmology.</p> Signup and view all the answers

<p>The SM is based on the symmetry group SU(3) ⊗ SU(2) ⊗ U(1).</p> Signup and view all the answers

<p>The color group of the theory of strong interactions is SU(3).</p> Signup and view all the answers

<p>The generator of the QED gauge group U(1) is the electric charge Q, given by Q = T3 + Y/2.</p> Signup and view all the answers

<p>The photon γ is massless.</p> Signup and view all the answers

<p>The breaking of the symmetry in the electroweak theory is called spontaneous symmetry breaking.</p> Signup and view all the answers

<p>The Standard Model (SM) provides a well-defined and consistent theoretical framework.</p> Signup and view all the answers

<p>The strength is determined by the Fermi coupling constant $G_F$.</p> Signup and view all the answers

<p>The effective interaction for muon decay is given by $L_{\text{eff}} = \left(\frac{G_F},{\sqrt{2}}\right) \bar{\nu}<em>\mu \gamma</em>\alpha(1 - \gamma^5)\mu \bar{e} \gamma^\alpha (1 - \gamma^5)\nu_e$.</p> Signup and view all the answers

<p>The value of $G_F$ is $1.16639(1) \times 10^{-5} , \text{GeV}^{-2}$.</p> Signup and view all the answers

<p>The weak interactions derive their name from their intensity.</p> Signup and view all the answers

<p>The old low-energy description of weak interactions was the (V - A) ⊗ (V - A) four-fermion interaction.</p> Signup and view all the answers