Fundamental Particles in Physics: Leptons, Quarks, and Standard Model, Slides of Physics

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Standard

Model

Subatomic

World

Protons,

neutrons,

and

electrons

make

up

atoms.

Photons

are

particles

that

convey

electromagnetic

energy.

Force

carrier

These

make

up

most

of

the

material

universe.

Leptons

Leptons

are

fundamental

particles.

Interact weakly

no nuclear interaction

Able to exist in isolation

Electrons

are

stable.

Muons and taus are unstable.

Neutrinos

are

stable

and

very

low

mass.

Partner with charged leptons

Charged

leptons:

electron, e 

:^

MeV/c 2

m p

muon,



:^

GeV/c 2

m p

tau,



GeV/c 2

m p

Baryons

Baryons

have

atomic

mass

comparable

to

protons

and

neutrons.

Conserved quantity

First

artificial

ones

were

given

a

property

of

strangeness.

Quantum number

Later

ones

were

given

new

properties.

Charm, beauty, truth n p  



  

  

Quarks

Quarks

are

fundamental

building

blocks,

but

are

not

detected

directly.

Binding force too great

Stable quarks bind to others

Quarks

exist

in

hadrons

Baryons are three quarks

Mesons are a quark ‐anti quark pair.

Some

baryons

proton, p: uud

neutron, n: udd - lambda,

0

:^

uds

lambda ‐b,

b 0

udb

Some

mesons

pi ‐minus,



:^

ud

k

plus,

K

:^

us

J/psi,

:^

cc

Standard

Model

The

fundamental

particles

can

be

placed

into

a

compact

table.

Standard Model

Separate matter from force carriers

The

leptons

and

quarks

fall

into

three

related

generations.

Normal mater in first generation next