physics lecture3 slides

Large Hadron Collider

Dark Energy2011 Nobel Prize

The Hydrogen Atom

The Hydrogen Atom

Quantum Mechanics

The Hydrogen Atom

Nuclear weapons

The Hydrogen Atom

LargeHadronCollider

Smashing protons togetherat enormously high energies

Learn about forces of nature

Learn about the universe

Learn about fundamental particles

Unifying the Forces of Nature

4 Forces

Gravity

17th Century

Electromagnetism

19th Century

Weak Force

20th Century

Plutonium

Nagasaki

Strong Force

Helium20th century

Why do protons and neutrons stick together?

Strong Force

Quantum Chromodynamics

=

Quarks inside the proton and neutron

. . . held together by gluons

Unifying the Forces of Nature

Find 1 theory that describes everything

Theory of Everything

electroweak

FORCES OF NATURE:

strong

electromagnetic

gravity

weak

Theory ofEverything

StandardModel

“Periodic Table” of Particle Physics

QUARKS

LEPTONS

UP

DOWN

CHARM

STRANGE

TOP

BOTTOM

Electron neutrino

ELECTRON

Muon neutrino

MUON

Tau neutrino

TAU


QUARKS

LEPTONS

UP

DOWN

CHARM

STRANGE

TOP

BOTTOM

Electron neutrino

ELECTRON

Muon neutrino

MUON

Tau neutrino

TAU

never found free in nature;always bound


QUARKS

LEPTONS

UP

DOWN

CHARM

STRANGE

TOP

BOTTOM

Electron neutrino

ELECTRON

Muon neutrino

MUON

Tau neutrino

TAU

never found free in nature;always bound

Can run free


QUARKS

LEPTONS

UP

DOWN

CHARM

STRANGE

TOP

BOTTOM

Electron neutrino

ELECTRON

Muon neutrino

MUON

Tau neutrino

TAU

Quarks

In principle, quarks are all found inside the proton

They have fractional charge !!!

UP + 2/3 charge

DOWN - 1/3 charge

Quarks



UP + 2/3 charge

DOWN - 1/3 charge

down

up up

PROTON

2/3 + 2/3 – 1/3 = +1

Quarks



UP + 2/3 charge

DOWN - 1/3 charge

down

down up

NEUTRON

2/3 – 1/3 – 1/3 = 0


QUARKS

LEPTONS

UP

DOWN

CHARM

STRANGE

TOP

BOTTOM

Electron neutrino

ELECTRON

Muon neutrino

MUON

Tau neutrino

TAU

Neutrino

Almost no mass

No charge

Passes through matter with almost no interaction

Neutrino

Almost no mass

No charge

Passes through matter with almost no interaction

My PhD was in neutrino physics

My PhD thesis advisor: Jack Steinberger

He was a Columbia professor

He won the Nobel Prize for finding that there were different types of neutrinos!

(Lederman, Steinberger, Schwartz: 1988 Nobel Prize)

All “Columbia” Nobel


QUARKS

LEPTONS

UP

DOWN

CHARM

STRANGE

TOP

BOTTOM

Electron neutrino

ELECTRON

Muon neutrino

MUON

Tau neutrino

TAU


QUARKS

LEPTONS

UP

DOWN

CHARM

STRANGE

TOP

BOTTOM

Electron neutrino

ELECTRON

Muon neutrino

MUON

Tau neutrino

TAU

Columbia Nobel Prize


QUARKS

LEPTONS

UP

DOWN

CHARM

STRANGE

TOP

BOTTOM

Electron neutrino

ELECTRON

Muon neutrino

MUON

Tau neutrino

TAU

“Baby Bear” “Mama Bear” “Papa Bear”


QUARKS

LEPTONS

UP

DOWN

CHARM

STRANGE

TOP

BOTTOM

Electron neutrino

ELECTRON

Muon neutrino

MUON

Tau neutrino

TAU

“Baby Bear” “Mama Bear” “Papa Bear”

~170x’s proton mass

We have no idea why there arethree columns in the ParticlePhysics “periodic table”

Understanding the origin of mass is a major challenge for the field of particle physics

“Periodic Table of Force Carriers”

Electricity and Magnetism Photon

Weak W-boson, Z-boson

Strong Gluon

Gravity is not accounted for by our Standard Model

“Periodic Table of Force Carriers”

Photons γ No mass

W-boson, Z-boson W, Z Very Massive

Gluons g No mass

Anti-Matter

Every charged particle has an anti-particlepartner with opposite sign.

electrons (-1) positrons (+1)

quarks anti-quarks

up (+2/3) anti-up (-2/3)

down (-1/3) anti-down (+1/3)

sharedNobelwith mythesisadvisor

Higgs Particle

Particle that gives MASS to other particles

One missing particle in the Standard Model

Mass is expected to be about 120x’s proton mass

HOW DO WE STUDY THESE FORCES?

BUILD HIGH ENERGY MACHINES CALLED:

“ACCELERATORS”

Large Hadron Collider

LHC

LHC

7 Trillion eV

proton proton

7 Trillion eV

(1 TeV = 1 Trillion eV)

1 million eV = 106 eV = 1 MeV

1 billion eV = 109 eV = 1 GeV

1 trillion eV = 1012 eV = 1 TeV

Last Lecture

Proton rest energy E= mc2 ~ 1 GeV

How fast is proton traveling?E=γmc2 = 7 TeV

For the proton:

!

" =Emc 2

=7TeV1 GeV

= 7,000

!

" =1

1 # v2

c2Solve for proton velocity:

v = 0.999999990 c

Remember: c = 3 x 108 m/s

How deep inside the proton willone see with the LHC?

!

" =hcE

!

" =hcE

=4 #10$15 eV $ sec( ) 3 #108m /s( )

7 #1012 eV%10$19meters

proton diameter is ~10-15 meters Looking deepinside the proton

In the LHC tunnel

The ATLAS Detector

ATLAS Detector without ‘insides’

Learn how to be a ParticlePhysicist in 15 minutes

ATLAS DETECTOR PHILOSOPHY. . .

Beam’s eye view


particle


“electron-like” energy

all tracks

“proton-like” energy

muon tracks

“electron-like”energy

all tracks

“proton-like”energy

muon tracksonly chargedparticles givetracks

electron

photon

“proton-like”

neutrino

neutrino

detect bysearchingfor missingenergy in an event

2 jet event

3 jet event

Light quarks and gluons

Light quarks and gluons

Jets

Electron

electron

Photon

photon

neutrinos

neutrino

MissingEnergy

5 heavyobjects

Five Heavy Objects

Top quark

Bottom quark

W-boson

τ lepton

All decay and weknow the masses

Z-boson

Top quark

b-quark

W-boson

τ

All decay and we know the masses

Z-boson

W + b-quark

muon + neutrino

electron + neutrino

electron + positron

μ+ + μ-

c + electron + neutrino

3 charged tracks (jet-like)

SEARCHES. . .

new particles

or

new forces

MAJOR SEARCHES

(1) Supersymmetry

Major candidate for unification & Dark Matter

(2) Higgs Particle

Gives mass to matter in our universe

(3) ExoticsThe unexpected. . .

Supersymmetry

Look for high energy events with large missing energy

These events look as though they violate “Energy Conservation”:

Could explain Dark Matter in our Universe !!!

E=Mc2

proton proton

spray of high energy particles

Empty on the other side!

appears to violates energy conservation

Supersymmetry

proton proton

spray of high energy particles

Dark MatterE=mc2

Higgs decay to two photons

photon

photon

protonproton

Higgs decay to two photons

photon

photon

protonproton

60 GeV energy

60 GeV energy

Results on Higgs to two photon search (TODAY)

Simulation of amount of data that we have today

Blown up bya factor of 5compared toStandard Model

BLACK HOLES

Can the LHC create a Black Hole thatthen swallows earth?

Video Time . . .

Real answer to Black Hole question:

extremely high energy cosmic rays (1000’s x TeV)

Lots of “earth-eating” black holes should have been produced

Black Hole event simulation

Multijet event

Top quark event

Top quark event

W and b-quarkdecay

STATUS OF SUPERSYMMETRYSEARCH

Some theoretical prediction

(1) No discovery

(2) ATLAS has ruled out all masses less than the right edge of the bar

1000 GeV100 GeV

Supersymmetry

BLACK HOLES

STATUS OF HIGGSSEARCH

2010

Higgs Mass limits

2010

Nothing from LHC

Higgs Mass limits

2011

Higgs Mass limits, if no Higgs is found

2012 ?

Question time. . .

Beam ON

2012

Expect to collect ~5 x’s as much datacompared to 2011

Still 7 TeV Collisions

14 TeV Plans

2013 LHC Shutdown

Fix magnet safety system

(2008 explosion)

2014 Start up?

2015 Run with 14 TeV collisions

Run for many years >> 2020

Big Questions in Particle Physics

(1) Can all the forces between particles be understood in a unified framework?

(2) What do the properties of particles reveal about the nature and origin of matter and the properties of space and time?

(3) What are dark matter and dark energy, and how hasquantum mechanics influenced the structure of the universe?

(2006 National Research Council)

What about neutrinos and the speed of light?

Neutrinos faster than speed of light?

CERN Gran Sasso

730 kilometers

60 nanoseconds earlier than that expected from light (6 x 10-8 seconds)

(or think of it as neutrinos travel 18 meters further over the 730 km)

speed = distance/time

Neutrinos faster than speed of light?

Neutrinos would have arrived here 4 years earlier than the visible light,if they traveled as fast as the CERN experiment finds

Supernova1987A

168,000light yearsaway

Bet on Einstein

FINAL COMMENTS. . .

physics lecture3 slides

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