Intro to Particle and Nuclear Physics and the Long Island Gold Rush

Intro to Particle and Nuclear

Physics and the Long Island Gold

Rush

Steven ManlyUniv. of Rochester

REU seminarJune 1, 2006

steven.manly@rochester.edu

Inquiring minds want to know ...Inquiring minds want to know ...

Yo! What holds it together?Yo! What holds it together?

Fermi National Accelerator Fermi National Accelerator Laboratory (near Chicago)Laboratory (near Chicago)

CDFCDF MinosMinos

Stanford Linear Stanford Linear Accelerator CenterAccelerator Center

Event display from the SLD Event display from the SLD experiment at SLACexperiment at SLAC

What forces exist in nature?

What is a force?

How do forces change with energy or temperature?

How has the universe evolved?

How do they interact?

Force Source Range StrengthGravitation mass infinite 10-39

Electromagnetism Electriccharge

infinite 10-2

Strong nuclear Colorcharge

10-15 m 1

Weak nuclear Weakcharge

10-18 m 10-5

quarks leptonsGauge bosons

u c t

d s b

e

e

W, Z, g, Gg

Hadrons

Baryons qqq qq mesons

p = uud

n = udd

K = us or us

= ud or ud

Strong interaction

nuclei

e

atomsElectromagnetic

interaction

Mini-Ph.D. – Quantum Mechanics 101 Mini-Ph.D. – Quantum Mechanics 101

Lesson 1:Lesson 1:

Size actually does matter.Size actually does matter.

Determine the postion and velocity of a car … no problem

Determine the postion and velocity of a small particle … no problem

Problem!

Heisenberg uncertainty

principle

Cannot have perfect

knowledge of both the position

and velocity

Heisenberg

Dear Steve,

Party

relatively hard!

-Al

The fundamental nature of forces: virtual particlesThe fundamental nature of forces: virtual particles

Et h Heisenberg E = mc2 Einstein

e-

ee++ee--

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ee++ee--qqqq

ee++ee--

qqqq ee++ee--

qqqqee++ee--

qqqq

ee++ee--qqqq

ee++ee--

qqqq

ee++ee--

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ee++ee--

qqqq

ee++ee--

qqqq

ee++ee--

qqqq qqqq

qqqq

ee++ee--

qqqq

ee++ee--

qqqq

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ee++ee--

Much ado about NOTHING:Much ado about NOTHING:

Nothing is somethingNothing is something

Nothing has energy Nothing has energy

Nothing interacts with somethingNothing interacts with something

-R. Kolb

qqqq

qqqq

qqq

qqq

qqq

qqq

A contribution to mass at the quantum levelA contribution to mass at the quantum level

Strongly interacting particles interact with the vacuum

condensate … which can make them much heavier than the constituent quark masses.

-MSSL astrophysics group

BANG!

TIME

Very hot, dense primordial soup of fundamental particles

At 0.000001 second after bang, protons and neutrons form

At 3 minutes, light nuclei form

At ~300,000 years, t = 3000 degrees, atoms form and light streams freely

t=~13 billion years, Brittney Spears gets married … again

Modern accelerators study processes at energies that existed VERY early in the universe

Another form of time travel !

What were forces like at those temperatures?

What types of particles existed?

Strong color fieldEnergy grows with separation !!!E=mc2 !“white” proton

quark

quark-antiquark paircreated from vacuum

“white” proton(confined quarks)

“white” 0

(confined quarks)

Quantum Chromodynamics Quantum Chromodynamics QCDQCD

distance

energy density, temperature

rela

tive

stre

ngth

asymptotic freedomSimilar to QED … Similar to QED … except the gauge field except the gauge field

carries the chargecarries the charge

Thanks to Mike Lisa (OSU) for parts of this animation

e+e- collisions

Heavy ion collisions

Relativistic heavy ions at Brookhaven National Laboratory

RHIC BRAHMSPHOBOSPHENIX

STAR

AGS

TANDEMS

Relativistic Heavy Ion Collider (RHIC)

1 km

v = 0.99995c = 186,000 miles/sec

Thanks to M. Lisa for parts of this slide

STAR ~500 Collaborators

One collision seen by STAR TPC

The PHOBOS Detector

137000 Silicon Pad Channels

1m

Spectrometer

Octagon

Vertex

Ring CountersPaddle Trigger Counter

Cerenkov Counter

Time of Flight

Collision region is football shaped

Elliptic flow12

63

9

12 3 6 9 12

Num

ber o

f par

ticle

s

(reaction plane)

Flow quantifiedFlow quantified

dN/d(R ) = N0 (1 + 2V1cos (R) + 2V2cos (2(R) + ... )

b (reaction plane)

Elliptic Flow at 130 GeV

Phys. Rev. Lett. 89 222301 (2002)

(PHOBOS : Normalized Paddle Signal)

Hydrodynamic limit

STAR: PRL86 (2001) 402 PHOBOS preliminary

Thanks to M. Kaneta

Flow vs Pt and Hydro describes low pt

vs. particle mass, fails at high pt and high-

T. Hirano

(consider velocity and early, self-quenching asymmetry)

Places to learn more:Particle and nuclear physics links

http://pdg.lbl.gov

http://particleadventure.org

http://www.slac.stanford.edu/gen/edu/aboutslac.html

http://www.bnl.gov/bnlweb/sciindex.html

http://www.bnl.gov/rhic/

http://public.web.cern.ch/public/

http://www.fnal.gov/

http://www.er.doe.gov/production/henp/np/index.html

http://www.science.doe.gov/hep/index.shtm