Do you know what’snext door?

Do you know what’snext door?

Did you know that next door to you isthe world’s most powerful particle

accelerator?

Do you know what’snext door?

Did you know that next door to you isthe world’s most powerful particle

accelerator?

Did you know that next door to youtwo of the building blocks of theentire universe were discovered?

Introductory Comments: Elementary ParticlesIntroductory Comments: Elementary Particles

The world we live in is exceedingly complicated. A scientist, trying to understand how the world works, notes the almost infinite variety of things: air, water, earth, rock, hard metals, mist, clouds and so on.

The earliest scientists proposed a strategy for understanding everything. In 480 B.C. the Greek philosopher Democritus proposed that all things were made of "atoms." These "atoms" were too small to see but in their ceaseless motions they could collide and accumulate. Democritus' ideas were, of course, primitive but essentially correct.

Today, we know that all matter is made of atoms, and that atoms are complex structures made of smaller and more elementary objects. To understand the most fundamental particles and the forces that cause them to cluster and interact to build up the things we can see and touch is, then, the "first science." All other sciences - materials science, chemistry, biology - ultimately must rest on the basic laws of nature that govern the behavior of the elementary particles.

I. Introduction to Fermilab

BowerSchool

Bower School

Wlison Hall (a.k.a. “High Rise”)

Robert Wilson:Founder of Fermilab

Leon Lederman:

• 2nd director of Fermilab•received Nobel Prize in physics•heck-of-a nice guy, not to mention•heck-of-a smart guy

John PeoplesFermilab’s 3rd Director

Mike Witheral

Present Fermlab Director

So what is this good for?

1. Each bit of progress was preceded by the knowledge of how it worked

2. The tools required to make such measurements have led to technical offshoots which we use everyday. Examples are: i. x-ray machinesii. Microwave ovensiii. televisions

II. The Standard Model

Of what is everything inthe universe made?

The Building Blocks of a Dew DropThe Building Blocks of a Dew Drop

A dew drop is made up of many molecules of water (1021 or a billion trillion). Each molecule is made of an oxygen atom and

two hydrogen atoms (H2O). At the start of the 20th century, atoms were the smallest

known building blocks of matter.

Each atom consists of a nucleus surrounded by electrons. Electrons are

leptons that are bound to the nucleus by photons, which are bosons. The nucleus of

a hydrogen atom is just a single proton. Protons consist of three quarks. In the

proton, gluons hold the quarks together just as photons hold the electron to the

nucleus in the atom

We know that we can categorize atoms

Nucleus: protons and neutrons

Electrons

AtomsAtomsAll things in nature are made up of atoms. Atoms are made up

of a central nucleus and electrons which orbit around the nucleus.The nucleus is made up of protons and neutrons, and is only

1/10,000, or 10-5, the size of the atom. That’s like putting a pea onthe 50 yard line of a football field; the pea is the nucleus and the

field is the size of the atom.

Remember that the atom is made up of other stuff!

Protons and NeutronsProtons and NeutronsProtons and neutrons are made up

of quarks. Two upquarks and a down quark make a

proton. (Two down quarksand an up quark make a neutron.)

Within the proton, thequarks and gluons areconstantly moving andmaking new particles.

In the end, many particles makeUp protons and neutrons.

Quarks, Leptons, and BosonsQuarks, Leptons, and Bosons

Physicists currently believe there are three types of basic building blocks of matter: quarks, leptons, and bosons.

Quarks and leptons make up everyday matter, which is held together by

bosons. Each boson is associated with a force. The photon, or light particle, is the unit of the electromagnetic force

which holds the electron to the nucleus in the atom. The gluon, holds quarks together in the nucleus of the atom.

The way these particles combine dictates the structure of matter.

For every quark and lepton, physicists have discovered a corresponding antiparticle.

These particles are referred to as antimatter. Antimatter was

first observed in decays of radioactive nuclei.

Antiprotons are composed of two anti-up quarks and one

anti-down quark. Anti-hydrogen (an antiproton and a

positron) was created at the European laboratory, CERN,

and at Fermilab in 1996.

AntimatterAntimatter

The Particle ZooThe Particle Zoo

All of these quarks can combine together tomake particles which we can see in our detectors.

We know of two ways that quarks can combine:

III. Introduction to Particle Accelerators

To see different sized objects we need different tools:

A Basic AcceleratorA Basic Accelerator

The Fermilab accelerator has two basic parts: the magnets and the RF cavities. The magnets keep charged particles moving in a circular path. The RF cavities pump energy into the particles each time they pass through the cavities. Particles complete many laps around the

accelerator ring and receive a small boost in energy with every lap.

Most accelerators have stages of acceleration.

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IV. Detecting Particles

How we see:

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V. Inferring physics from the detectors

Matter and EnergyMatter and Energy

Everyone has heard of Einstein’s famous formula:E = m c 2

Here, E is “energy”, m is “mass”, and c is the constant for

the speed of light. What this equation tells us is that we

can change energy into matter, and matter into energy.

Examples:• Burning a match• Photosynthesis• A demolition derby

In a particle accelerator, like the Tevatron, we can createnew matter in collisions of protons and anti-protons

Here’s how we do “physics”:Here’s how we do “physics”:

–We know what quarks exist to make up particles (baryons and mesons) that we can see in our detector.–We know that we can use a particle accelerator to make heavy particles through the mass-energy relationship E=mc2.–We know that heavy particles can decay into lighter particles.–We know the properties of many of these lighter particles.–If we can measure (detect) the lighter particles, we can “infer” that they came from the heavier particles, and thus from heavier quarks.

Example: my doctoral thesis experimentExample: my doctoral thesis experiment

To study the “b quark” , we detected “B-mesons”

Example: my doctoral thesis experimentExample: my doctoral thesis experiment

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VI. Other things at Fermilab

Astrophysics

Fermilab also has a place where people

with certain types of cancer can be

treated.