Topic 1 - Particles Flashcards
Alpha Radiation
Particles that each consist of two protons and two neutrons.
Annihilation
When a particle and its antiparticle meet, they destroy each other and become radiation.
Antibaryon
A hadron consisting of three antiquarks.
Antimatter
Antiparticles that each have the same rest mass and, if charged, have equal and opposite charge to the corresponding particle.
Antimuon
Antiparticle of the muon.
Antineutrino
The antiparticle of the neutrino.
Antiparticle
There is an antiparticle for every type of particle. A particle and its corresponding antiparticle have equal rest mass and, if charged, equal and opposite charge.
Antiquark
Antiparticle of a quark.
Atomic Number (Z)
The number of protons in the Nucleus of an Atom.
Baryon
A hadron consisting of three quarks.
Beta Radiation
Beta- particles are fast moving electrons emitted by unstable neutron-rich nuclei; Beta+ particles are fast moving positrons emitted by unstable proton-rich nuclei.
Conservation rules
Conservation of energy, momentum, charge, baryon number and lepton number applies to all particle interaction. Conservation of strangeness applies to strong interactions only.
Electromagnetic interaction
Interaction between two charged objects.
Electron Capture
Process in which an inner-shell electron of an atom is captured by the nucleus.
Energy
The capacity to do work.
Gamma radiation
High-energy photons emitted by unstable nuclei or produced in particle annihilations.
Hadron
Particles and antiparticles that can interact through the strong interaction.
Isotopes
Atoms of an element with different numbers of neutrons and the same number of protons.
Kaon (or K meson)
A meson that consists of a strange quark or antiquark and another quark or antiquark.
Lepton
Electrons, positrons, muons and antimuons, neutrinos and their antiparticles are classified as leptons because they cannot interact through the strong interaction. They interact through the weak interaction and, in the case of electrons and positrons, through the electromagnetic interaction.
Lepton Number
A lepton number is assigned to every lepton (+1) and antilepton (-1), on the basis that the total lepton number for each branch of the lepton family is always conserved.
Meson
A hadron consisting of a quark and an antiquark.
Muon
A lepton that is negatively charged and has a greater rest mass than the electron.
Neutrino
Uncharged lepton with a very low rest mass compared with the electron.
Neutrino types (or ‘branches’)
There are three types of neutrinos, the electron neutrino, the muon neutrino, and the tau neutrino. This Specification only requires knowledge of the electron neutrino and the muon neutrino branches (and their antiparticles) of the lepton family.
Nucleon
A neutron or proton in the nucleus.
Nucleon number A
The number of neutrons and protons in a nucleus; also referred to as the mass number.
Nuclide
A type of nucleus with a particular number of protons and neutrons.
Pair production
When gamma photon changes into a particle and an antiparticle.
Pion
A meson that consists of an up or down quark and an up or down antiquark.
Positron
Antiparticle of the electron.
Quark
Protons and neutrons and other hadrons consist of quarks. There are six types of quarks, they are: up, down, strange, charm, top and bottom. The specification requires only that students know the up, down and strange quarks.
Quark model (or standard model)
A quark can join with an antiquark to form a meson or with two other quarks to form a baryon. An antiquark can join with two other antiquarks to form an antibaryon.
Rest energy
Energy due to rest mass, equal to m0c^2 where c is the speed of light in a vacuum and m0 is the rest mass.
Specific charge
Charge/mass value of a charged particle.
Strangeness number
A strangeness number is assigned to every particle and antiparticle on the basis that strangeness is always conserved in the strong interaction, but not in the weak interaction or a decay involving a strange quark or antiquark.
Strong interaction
Interaction between two hadrons.
Strong nuclear force
Attractive force between nucleons that holds the nucleons in the nucleus.
Virtual photon
Carrier of the electromagnetic force; a photon exchanged between two charged particles when they interact.
W boson
Carrier of the weak nuclear force; w bosons have a non-zero rest mass and may be positive or negative.
Weak interaction
Interaction between two leptons
Weak nuclear force
Force responsible for beta decay.
