The Frontiers of Matter (in 1932)

The periodic chart orders thechemical elements accordingto their properties.It provides clues to the un-derlying atomic structure.The ‘fundamental particles’of the periodic chart are theatoms/elements themselves.

What are the atoms/elements made of?

Protons and neutronsWhat are the protons and neutrons made of?

Quarks and gluons

Jerry Gilfoyle Hunting for Quarks 1 / 36

The Frontiers of Matter (in 1932)

The periodic chart orders thechemical elements accordingto their properties.It provides clues to the un-derlying atomic structure.The ‘fundamental particles’of the periodic chart are theatoms/elements themselves.

What are the atoms/elements made of? Protons and neutrons

What are the protons and neutrons made of?

Quarks and gluons

Jerry Gilfoyle Hunting for Quarks 1 / 36

The Frontiers of Matter (in 1932)

The periodic chart orders thechemical elements accordingto their properties.It provides clues to the un-derlying atomic structure.The ‘fundamental particles’of the periodic chart are theatoms/elements themselves.

What are the atoms/elements made of? Protons and neutronsWhat are the protons and neutrons made of?

Quarks and gluons

Jerry Gilfoyle Hunting for Quarks 1 / 36

The Frontiers of Matter (in 1932)

The periodic chart orders thechemical elements accordingto their properties.It provides clues to the un-derlying atomic structure.The ‘fundamental particles’of the periodic chart are theatoms/elements themselves.

What are the atoms/elements made of? Protons and neutronsWhat are the protons and neutrons made of? Quarks and gluons

Jerry Gilfoyle Hunting for Quarks 1 / 36

The Frontiers of Matter (now)

The Universe is made ofquarks and leptons andthe force carriers.

The atomic nucleus is madeof protons and neutrons boundby the strong force.

The quarks are confined insidethe protons and neutrons.Protons and neutrons are NOT confined.

Jerry Gilfoyle Hunting for Quarks 2 / 36

Setting the Quarks Free

Despite quark confinement there is a way to get them out of the proton orneutron. Hit a quark hard enough with something small like an electronand if it is immersed in nuclear matter, the tug of the nearby protons andneutrons cancels some of the forces on the struck quark. We’ll model thisstruck quark as a particle moving through the nucleus bound to it originalpartners by a string that exerts a constant force. Does the quark make itout of the nucleus?

RPb

Lead nucleus

Incoming electron

Target quark confined to a proton

bv

Quark string

Scattered electron

Struck quark

vo = 3× 108 m/s|a| = 4× 1030 m/s2

b = 3.0× 10−15 mRPb = 7.1× 10−15 m

Jerry Gilfoyle Hunting for Quarks 3 / 36

One-Dimensional Motion

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 4 / 36

One-Dimensional Motion

A

B

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 5 / 36

One-Dimensional Motion

Δt

A

B

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 6 / 36

One-Dimensional Motion

Δx

Δt

A

B

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 7 / 36

One-Dimensional Motion

Δx

Δt

A

B

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 8 / 36

One-Dimensional Motion

A

B

Δt

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 9 / 36

One-Dimensional Motion

A B

Δt

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 10 / 36

One-Dimensional Motion

A

B

Δt

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 11 / 36

One-Dimensional Motion

A

B

Δt

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 12 / 36

One-Dimensional Motion

A

B

Δt

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 13 / 36

One-Dimensional Motion

Tangent line

A

B

Δt

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 14 / 36

One-Dimensional Motion

A

B

A BA

B

A

B

A

B

Tangent line

time (t)

positio

n(x)

Jerry Gilfoyle Hunting for Quarks 15 / 36

One-Dimensional Motion

An elevator in the world’s tallestbuilding, the Burj Dubai in Dubai,United Arab Emirates, is mov-ing and its vertical position is de-scribed by the following equation

x(t) = A+ Bt + Ct2

where A = 5.0 m, B = 2.1 m/s,and C = −4.9 m/s2. What is theinstantaneous velocity at any timet? What is the average velocitybetween two times t0 = 0.0 s andt1 = 1.0 s?

Jerry Gilfoyle Hunting for Quarks 16 / 36

Position and Velocity

Jerry Gilfoyle Hunting for Quarks 17 / 36

Captain Kirk’s Bad Day

The starship Enterprise has lostpower and is plunging straight intothe heart of a black hole. Its velocityas a function of time is described by

v(t) = F + Gt

where F = 2.0 × 107 m/s and G =9.0× 1010 m/s2.

What is the instantaneous accelera-tion?

Do the velocity and acceleration ver-sus time plots make sense?

Jerry Gilfoyle Hunting for Quarks 18 / 36

Catching Up

At the instant a traffic light turns green, a ‘car’ starts with a constantacceleration a = 2.2 m/s2. At the same instant a truck is 5.0 m behindthe car and traveling with a constant speed vt = 9.5 m/s. How far doesthe car travel before overtaking the truck? What do the position versustime plots look like for the car and the truck?

Car

Truck

time (t)

Positio

n(x)

Jerry Gilfoyle Hunting for Quarks 19 / 36

Catching Up

At the instant a traffic light turns green, a ‘car’ starts with a constantacceleration a = 2.2 m/s2. At the same instant a truck is 5.0 m behindthe car and traveling with a constant speed vt = 9.5 m/s. How far doesthe car travel before overtaking the truck? What do the position versustime plots look like for the car and the truck?

Car

Truck

time (t)

Positio

n(x)

Jerry Gilfoyle Hunting for Quarks 19 / 36

EEEEKKK!!

Two trains, one traveling at 20 m/s and the other at 40 m/s, are headedtoward one another along a straight, level track. When they are 950 mapart, each engineer sees the other’s train and instantly applies the brakes.The slow-moving train stops. The brakes decelerate each train at a rate of1.0 m/s2. Is there a collision? If so, how long after the brakes are applied?

Jerry Gilfoyle Hunting for Quarks 20 / 36

EEEEKKK!!

Two trains, one traveling at 20 m/s and the other at 40 m/s, are headedtoward one another along a straight, level track. When they are 950 mapart, each engineer sees the other’s train and instantly applies the brakes.The slow-moving train stops. The brakes decelerate each train at a rate of1.0 m/s2. Is there a collision? If so, how long after the brakes are applied?

Jerry Gilfoyle Hunting for Quarks 20 / 36

Don’t Do This At Home

A window washer named Chris Sag-ger is reported to have fallen (as-sume starting from rest) 67 metersfrom a building where he was work-ing, landed on a car, and lived. Sup-pose the roof of the car was com-pressed 1.45 m. Ignoring air resis-tance what is his speed just beforehitting the car? Treating his accel-eration as constant, how long did ittake him to come to a stop after hemade contact with the box? Whatwas his acceleration?

Jerry Gilfoyle Hunting for Quarks 21 / 36

Measurement and Uncertainty

True value

Same number of

measurements with

different standard

deviations Same average

x

Nu

mb

er

of

Me

asu

rem

en

ts

Average and Standard Deviation

Jerry Gilfoyle Hunting for Quarks 22 / 36

Precision versus Accuracy

Not precise. Precise, but not accurate. Precise and accurate.

True value

x

Nu

mb

er

of

Me

asu

rem

en

ts

Average and Standard Deviation

True value

x

Nu

mb

er

of

Me

asu

rem

en

ts

Average and Standard Deviation

True value

x

Nu

mb

er

of

Me

asu

rem

en

ts

Average and Standard Deviation

Jerry Gilfoyle Hunting for Quarks 23 / 36

Understanding some Statistics

x

Nu

mb

er

of

Me

asu

rem

en

ts

Average and Standard Deviation

Jerry Gilfoyle Hunting for Quarks 24 / 36

Understanding some Statistics

True value

σ σ

x

Nu

mb

er

of

Me

asu

rem

en

ts

Average and Standard Deviation

Jerry Gilfoyle Hunting for Quarks 25 / 36

Understanding some Statistics

True value

σ σ68% of area

x

Nu

mb

er

of

Me

asu

rem

en

ts

Average and Standard Deviation

Jerry Gilfoyle Hunting for Quarks 26 / 36

Does the quark escape?An electron strikes the quark bound inside a proton that is a constituent ofa lead nucleus in the configuration shown in the figure. The quark is nearthe surface of the nucleus. The collision gives the quark an initial velocity~vo and an acceleration ~a as it moves through the nuclear medium. Seebelow for numbers. Does the quark make it out of the nucleus?

vo = 3× 108 m/s|a| = 4× 1030 m/s2

b = 3.0× 10−15 mRPb = 7.1× 10−15 m

RPb

Lead nucleus

b

Struck quark

v0

x

y

Jerry Gilfoyle Hunting for Quarks 27 / 36

Does the quark escape?An electron strikes the quark bound inside a proton that is a constituent ofa lead nucleus in the configuration shown in the figure. The quark is nearthe surface of the nucleus. The collision gives the quark an initial velocity~vo and an acceleration ~a as it moves through the nuclear medium. Seebelow for numbers. Does the quark make it out of the nucleus?

vo = 3× 108 m/s|a| = 4× 1030 m/s2

b = 3.0× 10−15 mRPb = 7.1× 10−15 m

RPb

Lead nucleus

b

Struck quark

v0

x

y

Jerry Gilfoyle Hunting for Quarks 27 / 36

Turning Around 1

Jerry Gilfoyle Hunting for Quarks 28 / 36

Position and Velocity

Jerry Gilfoyle Hunting for Quarks 29 / 36

Changing Motion

Jerry Gilfoyle Hunting for Quarks 30 / 36

Changing Motion

Jerry Gilfoyle Hunting for Quarks 31 / 36

Changing Motion

Jerry Gilfoyle Hunting for Quarks 32 / 36

Turning Around 1

Jerry Gilfoyle Hunting for Quarks 33 / 36

Turning Around 2

Jerry Gilfoyle Hunting for Quarks 34 / 36

Turning Around 3

Jerry Gilfoyle Hunting for Quarks 35 / 36

Personal Information

Name:

How many semesters of physics?

How many semesters of calculus?

Preferred personal pronouns?

Jerry Gilfoyle Hunting for Quarks 36 / 36