June 27, 2015Lynn Cominsky1 Introduction to Particle Physics Professor Lynn Cominsky.

April 18, 2023 Lynn Cominsky 1

Introduction to Particle Physics

Professor Lynn Cominsky


Big Bang Timeline

We are here

Planck Era


Epo’s Chronicles: Planck Time


Big Bang Revisited

Extrapolating back in time, we conclude that the Universe must have begun as a singularity – a place where the laws of physics and even space and time break down

However, our theories of space and time break down before the singularity at a time known as the Planck time

The Planck scale refers to the limits of mass, length, temperature and time that are what can be measured using the Uncertainty principle


Planck scale activity

The goal of this activity is to calculate the Planck mass, length, time and energy.

Remember

Uncertainty Principle x p ≥ h/2

Uncertainty Principle E t ≥ h/2


Unified Forces

The 4 forces are all unified (and therefore symmetric) at the Planck scale energy

Planck scale

The phase transition which splits off the strong nuclear force is what triggers inflation


The Vacuum Era Planck era

10-43 s after the Big Bang Temperature (kT) ~1019 GeV Beginning of time – time and space are no longer

separate entities Emergence of spacetime

Inflationary era < 10-10 s, kT ~ 100 GeV Vacuum energy dominates, driving Universe to

enormous size Fluctuations may be formed that eventually turn

into large scale structure


Epo’s Chronicles: Inflation


Radiation Era

Creation of Light>10-36 s after Big Bang - kT ~ 100 GeVVacuum energy turns into light, and equal

amounts of matter vs. anti-matterGravitational attraction beginsBackground radiation energy originatesDark matter may be formed


Radiation Era Creation of Baryonic Matter (Baryogenesis)

>10-36 s after Big Bang Temperature (kT) ~ 100 GeV A small excess of quarks and electrons is formed

(compared to anti-quarks and anti-electrons)

Electroweak (Unification) Era 10-10 s after the Big Bang, kT ~ 100 GeV Forces and matter become distinguishable forms of

energy with different behavior Masses of particles are defined May include baryogenesis


Radiation Era Strong Era

10-4 s after the Big Bang - kT~ 0.2 Gev Quark soup turns into neutrons and protons Dark matter may be formed

Electroweak Decoupling 1 s after the Big Bang - kT ~ 1 MeV Neutrons and protons no longer interchange

(leaving 7 p for each n) Cosmic neutrino background is formed Electrons and positrons annihilate, adding energy

to the cosmic background radiation, and an excess of electrons


Radiation Era Creation of light element nuclei

100 s after the Big Bang – kT ~ 0.1 MeV Nucleosynthesis begins as neutrons and protons

are cool enough to stick together to form Helium, some Deuterium, and a little bit of Lithium

Precise elemental abundances are established

Radiation Decoupling 1 month after the Big Bang – kT ~ 500 eV Interactions between matter and radiation are

fewer and farther between Blackbody background spectrum is determined


Big Bang Timeline

We are here

Radiation Era


Atomic Particles

Atoms are made of protons, neutrons and electrons

99.999999999999% of the atom is empty space Electrons have locations

described by probability functions

Nuclei have protons and neutrons

nucleus

mp = 1836 me


Leptons An electron is the most common example of a lepton

– particles which appear pointlike Neutrinos are also leptons There are 3 generations of leptons, each has a

massive particle and an associated neutrino Each lepton also has an anti-lepton (for example the

electron and positron) Heavier leptons decay into lighter leptons plus

neutrinos (but lepton number must be conserved in these decays)

Lepton number: =+1 for leptons, -1 for anti-leptons, and 0 for non-leptons


Types of Leptons

Lepton Charge

Mass (GeV/c2)

Electron neutrino

0 0

Electron -1 0.000511

Muon neutrino

0 0

Muon -1 0.106

Tau neutrino

0 0

Tau -1 175


Quarks

Experiments have shown that protons and neutrons are made of smaller particles

We call them “quarks”, a phrase coined by Murray Gellman after James Joyce’s “three quarks for Muster Mark”

Every quark has an anti-quark

Modern picture of atom


Atomic sizes

Atoms are about 10-10 m Nuclei are about 10-14 m Protons are about 10-15 m The size of electrons and

quarks has not been measured, but they are at least 1000 times smaller than a proton


Types of Quarks

Flavor Charge Mass (GeV/c2)

Up 2/3 0.003

Down -1/3 0.006

Charm 2/3 1.3

Strange -1/3 0.1

Top 2/3 175

Bottom -1/3 4.3

Quarks come in three generations

All normal matter is made of the lightest 2 quarks


Quarks

Physics Chanteuse

Up, down, charm, strange, top and bottomThe world is made up of quarks and leptons…

Quark Sing-A-long


Combining Quarks

Particles made of quarks are called hadrons

3 quarks can combine to make a baryon (examples are protons and neutrons)

A quark and an anti-quark can combine to make a meson (examples are muons, pions and kaons)

proton

meson

Fractional quark electromagnetic charges add to integers in all hadrons

Baryon numbers

Baryon numbers are only approximately conserved in particle interactions

The baryon number is defined on the basis of quarks and anti-quarks:NB = 1/3 (Q – Q)

What is the baryon number of a proton?What is the baryon number of a pi

meson?



Rules of the game activity

Analyze the observed particle events to see what the combination rules are


Color charges

Each quark has a color charge and each anti-quark has an anti-color charge

Particles made of quarks are color neutral, either R+B+G or color + anti-color

Quarks are continually changing their colors – they are not one color


Gluon exchange Quarks exchange gluons

within a nucleon

movie


Atomic Forces

Electrons are bound to nucleus by Coulomb (electromagnetic) force

Protons in nucleus are held together by residual strong nuclear force

Neutrons can beta-decay into protons by weak nuclear force, emitting an electron and an anti-neutrino

F = k q1 q2

r2

n = p + e +


Fundamental Forces

Gravity and the electromagnetic forces both have infinite range but gravity is 1036 times weaker at a given distance

The strong and weak forces are both short range forces (<10-14 m)

The weak force is 10-8 times weaker than the strong force within a nucleus


Force Carriers

Each force has a particle which carries the force

Photons carry the electromagnetic force between charged particles. Photons are not affected by the EM force.

Gluons carry the strong force between color charged quarks but they are affected by the strong force.


Force Carriers

Separating two quarks creates more quarks as energy from the color-force field increases until it is enough to form 2 new quarks

Weak force is carried by W and Z particles; heavier quarks and leptons decay into lighter ones by changing flavor


Force Summary

End of Part 1 Next you will hear from Helen Quinn,

Professor at SLAC Prof. Quinn got her PhD at Stanford, but is

originally from Australia She also worked at DESY (German

accelerator) and at Harvard The Peccei-Quinn theory has been proposed

to explain why strong interactions maintain CP symmetry when weak ones do not (more about CP symmetry later.)

April 18, 2023 Lynn Cominsky

Tuesday AM

Discussion – what were the hardest concepts for you to understand yesterday?



Particle DecaysNuclear decay – nucleus splits into

smaller constituents

Particle decay – fundamental particles “decay” (transform) into other (totally different) fundamental particlesHow does this happen?What are the rules?

238U

234Th

c

s

W

u

d

Any difference in masses is carried away as kinetic energy by new particles


Weak Particle Decays

Fundamental particle decays into another, less massive, fundamental particle plus a force-carrier particle This is always a W-boson for fundamental

particles In this example, the charm quark decays into a W

plus strange quark. The force-carrier particle then decays into

other fundamental particles (in this example, W decays into up and down quarks)

However, the mass of the W boson is 80.4 GeV/c2 – this is much more than a quark!


Virtual particles So how does a charm quark decay into

something that is heavier than itself? The answer lies in the Uncertainty principle

The W-boson only lives for a very short time (~3 x 10-25 s)

Its heavy mass limits the range of the weak force (It is equal to EM at 10-18 m.)

Since it lives for such a short time, it is known as a “virtual particle”

Initial energy and final energy (including kinetic energy of final particles) are still equal.

Flavors can change, charges can change.


Electromagnetic Decays

Example: 0 meson is made of a quark-anti-quark pair, which can annihilate, creating two photons

Photons are the force-carriers for the EM force.Photons are massless, hence the range of

the EM force is infinite

Neither colors or charge change.


Strong decays

The c particle is a charm-anticharm meson. It can undergo a strong decay into two gluons (which emerge as hadrons).

Gluons are strong-force carrier particles, and they mediate decays involving color changes.

Charge does not change, but color changes.


Annihilations

Two anti-particles annihilate, create force-carrier particles, which then decay into an entirely new pair of particles (or maybe two photons)


Unifying Forces

Weak and electromagnetic forces have been unified into the “electroweak” force They have equal strength at 10-18 m Weak force is so much weaker at larger distances

because the W and Z particles are massive and the photon is massless

Attempts to unify the strong force with the electroweak force are called “Grand Unified Theories”

There is no accepted GUT at present


Gravity

Gravity may be carried by the graviton – it has not yet been detected

Gravity is not relevant on the sub-atomic scale because it is so weak

Scientists are trying to find a “Theory of Eveything” which can connect General Relativity (the current theory of gravity) to the other 3 forces

There is no accepted Theory of Everything (TOE) at present


Spin

Spin is a purely quantum mechanical property which can be measured and which must be conserved in particle interactions

Particles with half-integer spin are “fermions” Particles with integer spin are “bosons”

* Graviton has spin 2


Quantum numbers

Electric charge (fractional for quarks, integer for everything else)

Spin (half-integer or integer) Color charge (overall neutral in particles) Flavor (type of quark) Lepton family number (electron, muon or tau) Fermions obey the Pauli exclusion principle –

no 2 fermions in the same atom can have identical quantum numbers

Bosons do not obey the Pauli principle


Standard Model

6 quarks (and 6 anti-quarks) 6 leptons (and 6 anti-leptons) 4 forces Force carriers (, W+, W-, Zo, 8 gluons, graviton)


Some questions

Do free quarks exist? Did they ever? Why do we observe matter and almost no antimatter if

we believe there is a symmetry between the two in the universe?

Why can't the Standard Model predict a particle's mass? Are quarks and leptons actually fundamental, or made

up of even more fundamental particles? Why are there exactly three generations of quarks and

leptons? How does gravity fit into all of this?


Particle Accelerators

The Standard Model of particle physics has been tested by many experiments performed in particle accelerators

Accelerators come in two types – hadron and lepton Heavier particles can be made by colliding lighter

particles that have added kinetic energy (because E=mc2)

Detectors are used to record the shower of new particles that results from the collision of the particle/anti-particle beams

Cloud Chamber Demo

We have a diffusion cloud chamber that will show us some particle tracks


High Voltage

Types of particles

Alpha particles = Helium nucleiBeta particles = either electrons or

positronsGamma “particles” = photonsCosmic rays = mostly protons, but also

nuclei of other elements.Which will we see in our Cloud

Chamber?


How it works

and particles ionize molecules of the alcohol in the cloud chamber

Vapor condenses on the ionized nuclei in the chamber

The drops of condensation appear to make tracks when lit up

X- and gamma-rays make energetic electrons, or e+/e- pairs

Can you predict which types of tracks are made by the various types of particles?



Bubble chamber Same principle as cloud

chamber, but uses super-heated gas rather than super-cooled liquid

Anti-proton enters at bottom – turns into 8 pions, one of which decays into a muon and a neutrino


How to make particle beams Electrons: Heating a metal causes electrons

to be ejected. A television, like a cathode ray tube, uses this mechanism.

Protons: They can easily be obtained by ionizing hydrogen.

Antiparticles: To get antiparticles, first have energetic particles hit a target. Then pairs of particles and antiparticles will be created via virtual photons or gluons. Magnetic fields can be used to separate them.

Particles are accelerated by changes in EM fields that push them along.


Types of accelerators Different types of collisions:

Fixed target: Shoot a particle at a fixed target. Colliding beams: Two beams of particles are

made to cross each other. (Creates more energy since two beams of particles are accelerated.)

Accelerators are shaped in one of two ways: Linacs: Linear accelerators, in which the particle

starts at one end and comes out the other. (Example: SLAC, which uses leptons.)

Synchrotrons: Accelerators built in a circle, in which the particle goes around and around and around (steered by magnetic fields). (Example: Fermilab and CERN, which use hadrons.)


FermiLab

Tevatron collides protons and anti-

protons at 2 TeV

Colliding Detector at Fermilab (CDF) D0


FermiLab The top quark was discovered at Fermilab – and 20 years

later, Fermilab observed single top quarks (not in pairs) Main goal is search for Higgs boson, new physics (CDF) Other experiments are looking for:

matter/anti-matter asymmetry in decays of Kaons and other mesons

Neutrino oscillations – from neutrinos made at Fermilab, traveling to Soudan mine (Minnesota, 450 miles away) and other long-baseline neutrino experiments

Many scientists collaborating on CMS at LHC (CERN) Dark matter searches (CDMS) Ongoing work on future experiments, such as a muon collider,

more neutrino detectors


A tour of the CDF detector

Virtual reality movie made at Fermilab by Joe Boudreau

movie


FermiLab

Only 1 out of 1010 collisions produces a top quark

Computer analyzes detector pattern to find mesons, a positron and evidence for a neutrino

Physicists deduce that this pattern also requires a W and b quark which come from a top quark decay


Find Mass of Top Quark

Analyze the events that are seen in the D0 detector

For each jet or particle, find the x- and y- components of the momentum (using a protractor). The amplitude of the momentum for each is given on the plot

What is the missing momentum? (x- and y- components)

What is the amplitude?


Figures for activity


Now find the top quark mass

Since all the momenta were expressed in units of GeV/c, you can add them all up

This collision made a top and anti-top pair – so the total of all the momentum amplitudes is the momentum of 2 tops

How did your answer compare to the measured value of 173 GeV/c ?

After the break….



Field Theories

1865 – James Maxwell unifies electricity and magnetism in the first field theory

Fields were proposed to explain how forces are carried between particles

Einstein’s theory of General Relativity is another example of a field theory

electromagnetic wave


Particles and Fields

Fields carry energy through spacetime Fields are present everywhere, including the

vacuum (which is the lowest energy state of all the fields)

Fields can act like both waves and particles Wave-like fields are called forces Particle-like fields are called matter or

photons Matter interacts with other matter through

forces


Quantum Electrodynamics

Quantum mechanics describes the laws of motion of sub-atomic particles

Interactions between sub-atomic particles are described by quantum field theories

QED is the quantum field theory which describes electromagnetic interactions at the sub-atomic level

Predictions from QED calculations are accurate to one part in a trillion


Quantum Electrodynamics

The 1965 Nobel prize for QED was awarded to Richard Feynman, Julian Schwinger and Sin-Itiro Tomonaga

Feynman diagrams are used to show the relation between particles and force carriers for all four forces

Feynman diagram for a

electromagnetic interaction


Electro-weak Unification

1979 Nobel Prize awarded to Steven Weinberg, Abdus Salam, and Sheldon Glashow for the development of a unified field theory of electroweak interactions

They predicted the W and Z bosons (which were discovered in 1983, Nobel in 1984 to Carlo Rubbia and Simon van der Meer)

Feynman diagram of a weak interaction


Electro-weak Unification

Q: If the electromagnetic and weak interactions are really two sides of the same coin, then why are the W and Z particles so massive (80 GeV) while the photon is massless?

A: In the early Universe, when the characteristic energy kT > 80 GeV, the electromagnetic and weak forces were united. As the Universe cooled out of the electroweak era, spontaneous symmetry breaking occurred which split out the W and Z


Symmetry Breaking

Here is an example: it is unclear which glass goes with which place setting until the first one is chosen


Spontaneous Symmetry Breaking

Balance a pencil on its tip – it has an equal chance to fall over in each direction. But when it falls over, it chooses a specific direction, and breaks the initial symmetry

Hydrogen and oxygen are symmetric molecules, yet when they combine to make water, the molecule has a characteristic angle of 105 degrees between the Hydrogen atoms.


Symmetries

Physical laws display mathematical symmetry Rotate a square through space by 90o - it will

look exactly the same Rotate a circle by any angle – it will also appear

the same Because a circle has more choices of rotation

angle, it is said to have a larger symmetry Physical laws can be invariant with respect

to changes in location, time or other types of transformations (rotation, velocity, etc.)


Symmetries

Patterns in the properties of particles can be described by mathematical symmetries which act on internal spaces – properties of the particles themselves, rather than its spacetime environment

Protons and neutrons are regarded as two different directions in an abstract internal space – although their charges are different, they have identical strong interactions (“nucleons”)

This is another example of a broken symmetry which is thought to be unified at higher energies


Transformation Laws

Laws of physics are the same at any location in space – this means that the universe is invariant under a “spatial” transformation

What if you reflect points in space through a mirror – “parity” transformation? (P) – No!

What if you turn every particle into its anti-particle – “charge conjugation” (C)? No!

But invariance is regained (almost) if you combine C and P – CP violation occurs at about 0.2% level (First proved with Kaons.)


CP Violation

CP means “charge-parity”, aka time-reversal symmetry – the symmetry that results from interchanging a particle with its anti-particle and sending it through a 3D mirror

CP violations were first observed in decays of K-mesons vs. anti-K-mesons – the decays happened at different rates (1980 Nobel, James Cronin and Val Fitch)

Studies of flavor changing interactions with K and B mesons should tell us more about CP physics


CP Violation Kaons oscillate between

two types– short-lived (green) which decay into 2 pions and long-lived (red), which decay into 3 pions

Both indirect and direct CP violation have now been observed

The weak force is responsible for these violations


CP Violation song

Written by Logan Whitehurst (formerly of the Jr. Science club, then in the Velvet Teen, now deceased) for my Cosmology class many years ago

http://www.juniorscienceclub.com/loganarchive/earthisbig/21%20sid_sheinberg_sings__cp_vi.mp3

Sid Sheinberg sings! CP Violation Song


Particle Accelerators-SLAC

2 mile long accelerator which can make up to 50 GeV electrons and positrons

Discovered the charm quark (also discovered at Brookhaven) and tau lepton; ran an accelerator producing huge numbers of B mesons.

Now doing photon science – Linac Coherent Light Source

LCLS is using x-ray laser beams to probe inside of atoms, removing one electron at a time


SLAC B-factory

Goal is to understand the imbalance between matter and anti-matter in the Universe

1 out of every billion matter particles must have survived annihilation

Decay rates of Bs and anti-Bs should be different

Explanation goes beyond the standard model


BaBar Experiment SLAC accelerator was used (until 2008) as an asymmetric

B-meson factory, making B-mesons and anti-B-mesons out of 9 GeV electrons and 3.1 GeV positrons. CP violation is observed in some of these decays.

Half of the 2008 Nobel Prize in Physics was awarded to Makoto Kobayashi and Toshihide Maskawa for their theory which simultaneously explained the source of matter/antimatter asymmetries in particle interactions and predicted the existence of the third generation of fundamental particles. The BABAR experiment at the SLAC National Accelerator Laboratory in the U.S., together with the Belle experiment at KEK in Japan, recently provided experimental confirmation of the theory, some thirty years after it was published, through precision measurements of matter/antimatter asymmetries. The other half of the Nobel prize went to Yoichiro Nambu for his theory of spontaneous symmetry breaking.


Quantum Chromodynamics

QCD is the quantum field theory which describes the interactions between quarks and gluons

It is difficult to use QCD to make predictions because the gluons carry a color charge and interact with each other

QCD is a non-linear theory which can only be calculated approximately - 10% accuracy for mass of proton – calculations take months of supercomputer time


Quantum Chromodynamics

1969 Nobel to Murray Gell-Mann for quark classification scheme

Internal symmetry in the pattern of quarks predicted the - particle and its mass

ddd ddu duu uuu

dds dus uus

dss uss

sss

= charge

grea

ter m

ass


Gauge Theories

Gauge theories are quantum field theories that have local symmetries physical laws remain the same when particle properties are exchanged at different locations in spacetime

Local internal symmetries actually require force carrier particles whose interactions create the forces

QED is an Abelian gauge theory Electro-weak Unification is a non-Abelian

gauge theory (1999 Nobel to t’Hooft and Veltman)


Abelian Transformations

Put a pen on the table.

Rotate it by 90o then by

180o

Now start over but this time

rotate it by 180o then by 90o

2D rotations are the same in either order


Non-Abelian Transformation

Put a pen on the table. Rotate it by 90o so the tip points to the floor then by 180o so the tip points up

Now start over but this time rotate it first by 180o then by 90o – you get a very different result!

3D rotations are not the same in either order


Beyond the Standard Model

Standard model describes every particle and interaction that has ever been observed in a laboratory

It has 18 arbitrary constants that are put in “by hand” – where do these come from?

The masses of the W and Z particles are not easily predictable from the Standard Model

The Standard Model also does not predict the pattern of masses and the generational structure – is a new symmetry needed?


18 Free Parameters

Fundamental electroweak mass scale (1)Strengths of the 3 forces (3)Masses of e-, and (3)Masses of u, c and t quarks (3)Masses of d, s and b quarks (3)Strength of flavor changing weak force (1)Magnitude of CP symmetry breaking (3)Higgs boson mass (1)


Grand Unification of Forces

Strengths of three forces depend on the energy at which the observations are made

Supersymmetric theories can unify the forces at higher energies than we can observe

strong

weak

electromagnetic 1016 GeV


Supersymmetry

Supersymmetry is a larger symmetry that treats the 3 forces as broken pieces of a larger whole, and can predict all the properties and interactions of the particles

Predicts a combination of coupling constants that agrees with what is measured in the electroweak unification regime

Predicts supersymmetric particle partners for each existing particle (the lightest “sparticle” is also known as a WIMP)


Supersymmetry

Sparticles have not yet been seen, but require experiments which can get to energies near 1 TeV (LHC? Fermi?)

GUTs allow the conversion of quarks to leptons through the exchange of a very massive particle

Since protons are made of quarks, this interaction would cause protons to decay

Non-supersymmetric GUTs predict short lifetimes for protons, and have been ruled out


Proton Decay

Supersymmetric predicted proton decay rate is a few per year per 50,000 metric tons (SuperK volume)

SuperKamiokande finds a proton lifetime > 1033 years (no events are seen in over three years study of a huge volume of protons) – can eventually reach 1034 years Super K detector


Neutrino Oscillations

A pion decays in the upper atmosphere to a muon and a muon neutrino

Neutrinos oscillate flavors between muon and tau


Neutrino Oscillations

High energy neutrinos that travel a short distance do not change their flavor

Low energy neutrinos that travel a long distance have a 50% chance of changing flavors

(m2c4) = 0.005 eV2


Neutrino Oscillations K2K (KEK to SuperK) was an experiment testing neutrino

oscillation results Neutrinos produced at KEK were measured at near detector

and then shot 250 km across Japan to SuperK detectors Final results from runs during 1999-2004: 158+/- 9 expected,

112 detected oscillations! Seeing oscillations means that neutrinos are not massless, as

assumed in the Standard Model


Epo’s Chronicles: Higgs Boson


Origin of Mass

Electroweak unification predicts the existence of yet another particle, the Higgs boson

The Higgs boson is a neutral particle with zero spin which is the force carrier for the Higgs field

The Higgs boson breaks the electro-weak symmetry which gives the W and Z much heavier masses than the photon

Interactions with the Higgs field are theorized to give mass to all the other particles


Higgs Boson Standard model physics predicts the mass of

the Higgs to be less than 150 GeV/c2. However if there is physics beyond the

standard model, then the Higgs mass could be as high as 1.4 TeV/c2

The data gathered at CERN (before LHC) set lower limit of 114.4 GeV/c2

As of January 2010, combined data from two experiments at Fermilab ruled out masses between 162 - 166 GeV/c2

LHC runs began again on March 30, 2010….


CERN

European Center for Particle Physics

Near Geneva, on France-Swiss border

CERN now has the Large Hadron Collider (LHC)

LHC is now the world’s highest energy accelerator – now colliding two beams of protons at 3.4 TeV, with a design limit of 7 TeV. (Also uses lead nuclei at up to 574 GeV.)


CERN

LHC detectors (designed to study 14 TeV energy scale, same as 10-12 s after Big Bang) ATLAS (looking for the Higgs boson et al.) CMS (Higgs, electro-weak symmetry breaking) ALICE (quark-gluon plasma studies) LHCb (matter/anti-matter asymmetry using B mesons)


How to find a Higgs

Two quarks each emit a W or Z boson which combine to make a neutral Higgs.


LHC rap

http://www.youtube.com/watch?v=j50ZssEojtM

Now approaching 6 million views…


Theory of Everything

Mathematical unification of gravity with the other 3 forces (which are governed by quantum mechanics)

Einstein was the first to try (and fail) to develop a ToE – unifying general relativity with quantum mechanics

Supersymmetry + quantum gravity and string theory are two attempts to develop a ToE


Anthropic Principle

Anthropic principle - physical forces and constants are precisely balanced to allow life

Is this balance an accident or part of a grand design by a grand designer?

If the laws of physics completely explain the creation of the Universe, then what role would there be for a Creator? (Hawking)

If there really is a ToE, then the beauty and order of the physical laws indicate that a Creator must have originated the laws (Davies)

Summary

Particle physics does a good job explaining observed particles and forces

Newest experiments are finding “physics beyond the standard model”

The search for the Higgs is the most important experiment going on today

Or maybe the search for supersymmetric particles which could be dark matter…..



Web Resources

The Particle Adventure http://particleadventure.org/

Georgia State University Hyperphysics http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html National Research Council study of Elementary Particle Physics http://www.nap.edu/readingroom/books/particle/#contents

Boston University HEP site http://hep.bu.edu

Nobel Prizes http://www.nobel.se

Brookhaven National Laboratory (RHIC) http://www.rhic.bnl.gov


extras


Relativistic Heavy Ion Collider

Brookhaven National Laboratory

Collides gold ions to form quark-gluon plasma to simulate Big Bang conditions

QGP has never been made on Earth but should exist inside neutron stars


RHIC Quark-Gluon Plasma

RHIC collision

simulations



Brookhaven National Laboratory

Collides gold ions to form quark-gluon plasma to simulate Big Bang conditions

QGP has never been made on Earth but should exist inside neutron stars


RHIC Quark-Gluon Plasma

June 27, 2015Lynn Cominsky1 Introduction to Particle Physics Professor Lynn Cominsky.

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Transcript of June 27, 2015Lynn Cominsky1 Introduction to Particle Physics Professor Lynn Cominsky.