Fundamental Particles and the Standard Model

A set of vocabulary flashcards reviewing fundamental particles, quarks, leptons, hadrons, gauge bosons, and their respective physical quantities based on the lecture material.

Hadron

A particle that feels the strong force; baryons and mesons are classified as hadrons because they are composed of quarks. They also feel the weak force.

Lepton

A fundamental particle that does not feel the strong force, divided into charged and uncharged leptons. They do, however, feel the weak force.

Unified atomic mass unit

A unit of mass defined as approximately $1.661 \times 10^{-27}\,\text{kg}$.

Fermi radius ($R_0$)

The proportionality constant representing the characteristic nuclear radius parameter, with a value of $1.2 \times 10^{-15}\,\text{m}$.

Nuclear radius formula ($R$)

The relationship $R = R_0 A^{1/3}$, where $R$ is the radius of the nucleus, $R_0$ is the Fermi radius, and $A$ is the mass or nucleon number.

Up quark ($u$)

A first-generation quark possessing an electric charge of $+\frac{2}{3}e$ and a rest mass of approximately $2.2\,\text{MeV}/c^2$.

Down quark ($d$)

A first-generation quark with an electric charge of $-\frac{1}{3}e$, a baryon number of $+\frac{1}{3}$, and a rest mass of approximately $4.7\,\text{MeV}/c^2$.

Charm quark ($c$)

A second-generation quark with an electric charge of $+\frac{2}{3}e$ and a rest mass of approximately $1.28\,\text{GeV}/c^2$.

Strange quark ($s$)

A second-generation quark with an electric charge of $-\frac{1}{3}e$ and a rest mass of approximately $96\,\text{MeV}/c^2$.

Top quark ($t$)

A third-generation quark with an electric charge of $+\frac{2}{3}e$ and a rest mass of approximately $173\,\text{GeV}/c^2$.

Bottom quark ($b$)

A third-generation quark (also called beauty) with an electric charge of $-\frac{1}{3}e$ and a rest mass of approximately $4.18\,\text{GeV}/c^2$.

Electron ($e^-$)

A first-generation lepton with an electric charge of $-1e$, a lepton number of $+1$, a baryon number of $0$, and a rest mass of approximately $0.511\,\text{MeV}/c^2$.

Positron ($e^+$)

The antiparticle of the electron, carrying an electric charge of $+1e$, a lepton number of $-1$, and a baryon number of $0$.

Electron neutrino ($\nu_e$)

A first-generation neutral lepton with a charge of $0$, a lepton number of $+1$, a baryon number of $0$, and an extremely small rest mass approximately equal to $0$.

Muon ($\mu^-$)

A second-generation lepton with an electric charge of $-1e$, a lepton number of $+1$, a baryon number of $0$, and a rest mass of approximately $106\,\text{MeV}/c^2$.

Muon neutrino ($\nu_\mu$)

A second-generation neutral lepton with an electric charge of $0$, a lepton number of $+1$, and a very small rest mass approximately equal to $0$.

Tau ($\tau^-$)

A third-generation lepton with an electric charge of $-1e$, a lepton number of $+1$, a baryon number of $0$, and a rest mass of approximately $1.78\,\text{GeV}/c^2$.

Tau neutrino ($\nu_\tau$)

A third-generation neutral lepton with an electric charge of $0$, a lepton number of $+1$, and a very small rest mass approximately equal to $0$.

Gluon ($g$)

A gauge boson mediator of the strong force with an electric charge of $0$, a rest mass of $0$, and a spin of $1$.

Photon ($\gamma$)

A gauge boson mediator of the electromagnetic force with an electric charge of $0$, a rest mass of $0$, and a spin of $1$.

Z boson ($Z$)

A neutral gauge boson of the weak force with an electric charge of $0$, a spin of $1$, and a rest mass of $91.2\,\text{GeV}/c^2$.

W boson ($W$)

A charged gauge boson of the weak force with an electric charge of $\pm 1$, a spin of $1$, and a rest mass of $80.4\,\text{GeV}/c^2$.

Higgs boson ($H$)

A fundamental scalar boson with an electric charge of $0$, a spin of $0$, and a rest mass of approximately $126\,\text{GeV}/c^2$.

Proton ($p$)

A hadron (baryon) having an electric charge of $+1$, a lepton number of $0$, and a baryon number of $+1$.

Antiproton ($\bar{p}$)

The antiparticle of the proton, having an electric charge of $-1$, a lepton number of $0$, and a baryon number of $-1$.

Neutron ($n$)

A neutral hadron (baryon) with an electric charge of $0$, a lepton number of $0$, and a baryon number of $+1$.

Pion ($\pi^0$)

A neutral meson with an electric charge of $0$, a lepton number of $0$, and a baryon number of $0$.

Pi-plus ($\pi^+$)

A charged meson with an electric charge of $+1$, a lepton number of $0$, and a baryon number of $0$, whose antiparticle is the pi-minus ($\pi^-$).

Xi-minus ($\Xi^-$)

A particle with an electric charge of $-1$, a lepton number of $0$, and a baryon number of $+1$, whose antiparticle is the Xi-plus ($\Xi^+$).