Lecture #2: Origin of Particles & Fields Flashcards
what is quanta?
discreet energy packets emmitted by electromagnetic waves
How can electromagnetic waves be emmited?
ONLY in quantized forms known as quanta
What is light’s dual nature?
consists of photons (discrete bundles of energy) and behaves like electromagnetic waves
What does an atom consist of?
nucleus and electrons moving around nucleus
What particles do the nucleus of atoms contain?
protons and neutrons
what do you call protons and neutrons collectively?
Baryons
every particle has an associated wave proportional to what?
it’s mass! (de broglie wave)
What is a Field?
a physical quantity that has a value at each point in space and time filled with energy and momentum.
true or false: field can be considered as collection of particles
true
Is the energy in a field quantized?
yes.. and the quantization can manifest itself as a particle
How do particles in a field interact?
- emiting a virtual particle that’s absorbed by the other particle
what is a virtual particle?
particle w/ extremely short lifetime
How do 2 electrons interact through electromagnetic force?
by exchanging a virtual photon and making the other photon responsible for the electromagnetic forces
what do you call a force carrying particles that mediate interactions ?
Bosons
what do you call particles that form the matter around us?
leptons and quarks
What are the 3 groups particles in nature can be divided into?
quarks, leptons, and force carrying particle (bosons)
what are the most fundamental particles?
quarks and leptons
how do quarks and leptons interact w/ each other?
by exchanging bosons
What 2 forms are matter in?
hadrons and leptons
Do hadrons or leptons consist of quarks?
hadrons
Depending on the spin of particles, where are they divided into?
fermions or bosons
_____ is the bulk of the matter in the universe
fermions
what particles keep quarks together?
gluons
What colors are quarks assigned?
red, blue, and green
true or false: quarks are bound together by strong interaction?
true
What 2 types do leptons consist of?
electrons and neutrinos
How many forces in nature and what are they?
4; gravity, electromagnetism, weak and strong
What is Gravity force?
- holds planets and stars together
- effective at large distances
What is electromagnetism force ?
- stronger than gravity
- depends on particles electric charge
What are strong and weak force ?
- operate over short distances of atomic size
- strong: binds atom nucleus together
- weak: responsible for nuclear reactions (fission and fusion)
how many quarks do protons and neutrons have each?
3
what type of protons do free neutrons decay to?
protons emitting an electron and a neutrino
what force mediated by gluon particles keeps neutrons and protons in the nucleus and quarks in neutrons and protons?
strong
what force meditated by W and Z particles is responsible for decay of particles ?
weak
what force is mediated by photons?
electromagnetic
what force is likely mediated by gravitons?
gravity
what is higgs field?
- fills all of space
- gives particles properties they have
mass of particles are result of what?
the interaction of those particles with w/ the higgs field via higgs boson
where does the higgs field exist?
everywhere
quarks ____interacts w/ higgs field gaining relatively large mass.
strongly
electrons ___interact w/ higgs field and are extremely light
slightly
photons___interact w/ higgs field and have no mass.
do not
what does higgs field exert when a particle moves through it?
resistance
where does inertial mass originate?
particles resist against acceleration from higgs field…entity that resists acceleration is the inertial mass of the particle.
What would happen to particles if higgs field did not exist?
all particles would be massless
what is lowest energy level called?
vaccum
what is spontaneous symmetry breaking?
process of the Higgs field assuming a non-zero value throughout space
what was the early universe?
first seconds of the universe where everything was radiation or energy
When energy is converted into matter, what else is formed ?
antimatter
For a proton-antiproton pair to form, the temperature must be what?
more than 1013 K
what do matter and antimatter release when they annihilate on contact?
energy
There must have been an asymmetry in the amount of matter and antimatter formed in order for there to be what?
to be predominance of ordinary matter today.
radiation creates what 2 things?
particles and antiparticles
when antiparticles and particles anihlate, what do they create?
radiation
what is charge-parity violation?
Charge (C) and Parity (P) are
two fundamental properties of
particles.
What is the charge in charge parity violation?
Charge is the same
as the electric charge
what does the parity in charge parity violation indicate?
Parity indicates the symmetry
of spatial coordinates.
If charge parity violation is NOT conserved, then what?
a particle and anti-particle have different properties
