Particles Flashcards
What is an antiparticle?
A particle with the same mass but opposite charge and quantum numbers as its corresponding particle.
What is the charge of a proton?
+1 e (elementary charge)
What is the charge of an electron?
-1 e (elementary charge)
What is the charge of a neutron?
0 (neutral)
What is a hadron?
A particle made of quarks, experiencing the strong nuclear force.
What are the two types of hadrons?
Baryons and mesons.
What is a baryon?
A hadron made of three quarks (e.g., proton, neutron).
What is a meson?
A hadron made of a quark and an antiquark (e.g., pion, kaon).
What is a lepton?
A fundamental particle that does not experience the strong nuclear force (e.g., electron, neutrino).
Name the six types of quarks.
Up, Down, Strange, Charm, Top, Bottom.
What are the charges of up, down, and strange quarks?
Up: +2/3 e, Down: -1/3 e, Strange: -1/3 e.
What is the quark structure of a proton?
uud (up-up-down).
What is the quark structure of a neutron?
udd (up-down-down).
What force binds quarks together?
The strong nuclear force, mediated by gluons.
What is the weak nuclear force responsible for?
Beta decay and changing quark types.
What is beta-minus decay?
A neutron turns into a proton, emitting an electron and an antineutrino.
What is beta-plus decay?
A proton turns into a neutron, emitting a positron and a neutrino.
What is a neutrino?
A nearly massless, neutral lepton that interacts weakly.
What are the three types of neutrinos?
Electron neutrino, Muon neutrino, Tau neutrino.
What is pair production?
A photon creates a particle-antiparticle pair, conserving energy and momentum.
What is annihilation?
A particle and its antiparticle collide, converting their mass into energy.
What is a Feynman diagram?
A graphical representation of particle interactions.
What is the exchange particle of the electromagnetic force?
The photon (γ).
What is the exchange particle of the strong force?
The gluon (g).
What are the exchange particles of the weak force?
The W+ , W- , and Z0 bosons.
What conservation laws must be obeyed in particle interactions?
Charge, Baryon number, Lepton number, and sometimes Strangeness.
What is the baryon number of a proton and neutron?
Both have a baryon number of +1.
What is the baryon number of an electron?
0, since electrons are not baryons.
What is the strangeness quantum number?
A property of strange quarks, conserved in strong interactions but not weak ones.
What is a kaon?
A meson containing a strange quark or antiquark.
What does the Higgs boson do?
It gives particles mass via the Higgs field.
What is the Standard Model?
The theory describing fundamental particles and their interactions (excluding gravity).
What happens in electron capture?
A proton captures an inner electron, turning into a neutron and emitting a neutrino.
What are cosmic rays?
High-energy particles from space, mostly protons and atomic nuclei.
What experiment discovered the electron?
J.J. Thomson’s cathode ray tube experiment.
What experiment confirmed the nucleus?
Rutherford’s gold foil experiment.
What is an alpha particle?
A helium-4 nucleus (2 protons, 2 neutrons).
What is a beta particle?
A high-energy electron (beta-minus) or positron (beta-plus).
What is a gamma ray?
A high-energy photon emitted from an atomic nucleus.
