Transcript My 1st introduction to fresh students

Evolution of the Universe
Too hot for quarks to bind!!!
Standard Model (N/P) Physics
QuarkGluon
Plasma??
Too hot for nuclei to bind
Nuclear/Particle (N/P) Physics
Hadron
Gas
Nucleosynthesis builds nuclei up to He
Nuclear Force…Nuclear Physics
Universe too hot for electrons to bind
E/M
Plasma
E-M…Atomic (Plasma) Physics
Solid
Liquid
Gravity…Newtonian/General Relativity
Gas
Today’s Cold Universe
Evolution of the Universe
Reheating Matter
•
Collisions of “Large”
nuclei convert beam
energy to temperatures
above 200 MeV or
1,500,000,000,000 K
– ~100,000 times higher
temperature than the
center of our sun.
•
Stars convert gravitational
energy to temperature.
They “replay” and finish
nucleosynthesis
~15,000,000 K in the center
of our sun.
“Large” as compared
to mean-free path of
produced particles.
An Old (and fundamental!) Question:
What is the structure of matter in the Universe?
Wood
Huge scale
Iron
Universe
Gravitational
Current building block
scale ~ 10-10 m
Electromagnetic
Leptons:
electron,
muon,
etc
scale ~ 10-15 m Strong
1
3
1
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3
1
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3
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2
3
2
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3
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2
3
Particles
Leptons
hadrons
Force carriers
meson
baryon
Gluons
Glue the quark
together
pion
u
d
Quarks are Confined inside Particles
Electromagnetic Interaction
• Force (r) ~ 1/r2
• Two charges can be broken apart
and set free
Strong Interaction (QCD)
•Strong interaction is mediated by gluons
•Both gluons and quarks has “color”
charge.
• V(r) = -k1/r + k2r, k2  1 GeV / fm,
constant force.
As two quarks are pulling away, energy increase. Color
string fragment into new pairs of quark. Single quarks
are confined inside particles. When energy is high
enough, it forms a jet.
How to Liberate Quarks and Gluons
Increase Temperature and/or Pressure
1,500,000,000,000 K
Water molecule is
~100,000 times
liberated with high
higher temperature
T and P
than the center of
our sun.
Librated Quarks and Gluons
Bayon
(pressure)
pressure
One Way to Increase Temperature or Pressure
Small “Bang”
Heavy alien object
hits the heavy earth
Tremendous kinetic
energy converted into
tremendous heat and
pressure.
One (Nuclear Physicist’) Way to Increase
Temperature or Pressure
Mini “Bang”
Heavy (Au) Nuclei hits
the heavy (Au) Nuclei
Tremendous kinetic
energy converted into
tremendous heat
Relativistic Heavy Ion Collider
RHIC
Relativistic Heavy Ion Collider
STAR
PHENIX Experiment
PHENIX
PHENIX Experiment
STAR Experiment
STAR
STAR Experiment
STAR Experiment
References to Study the New Matter
How an experiment take data
Au + Au Experiment (200GeV)
Final Data
Energy loss: parton loss lots of
energy (dE/dx = ???GeV/fm)
through bremsstrahlung when pass
through the new state of matter
(final state effect)
d + Au Control Experiment (200GeV)
Preliminary Data
Cronin enhancement: parton pT
smearing from random kick before
collisions (i.e. initial state effect)
Ways to Reveal the
QGP properties--Jet correlation
Rcone
Calculate angle between two
jet particles
Adler et al., PRL90:082302 (2003), STAR
trigger
away-side
near-side
Energy dissipated when parton pass through opaque medium.
How?
1 < pT (assoc) < 2.5 GeV/c
An analogy
http://www-news.uchicago.edu/releases/07/071106.liquids.shtml
Decreasing the number of glass
beads in the cross section of the
jet changes the behavior of the
granular stream after hitting the
target from liquid-like pattern to
one that looks like fireworks.
This latter pattern is more
characteristic of how individual
particles would behave after
hitting a wall.
A Large Ion Collider Experiment at the LHC: 30
times higher collision energy
ALICE @ PT2
ALICE
TOF TRD
HMPID
ITS
PMD
Muon Arm
PHOS
TPC
Size: 16 x 26 meters
Weight: 10,000 tons