Deck 41: Elementary Particles and Cosmology

Question 1

Protons and neutrons are not elementary particles. Consequently they are made from particles we call

A) quarks.
B) muons.
C) tachyons.
D) baryons.

Answer 1

quarks.

Question 2

One of the largest particle accelerators in the world is located in the United States, near Chicago, and is called

A) CERN.
B) Brookhaven.
C) SLAC.
D) Fermilab.

Answer 2

Fermilab.

Question 3

The Tevatron at Fermilab can yield protons with a maximum energy of

A) 1 MeV.
B) 1 GeV.
C) 10 GeV.
D) 1 TeV.

Answer 3

1 TeV.

Question 4

A bubble chamber allows physicists to

A) measure low temperatures.
B) measure the Sun's luminosity.
C) track charged particles.
D) detect gravitational waves.

Question 5

The leptons are the

A) proton and neutron.
B) electron, muon, tau, and their associated neutrinos.
C) pion and kaon.
D) six quarks.

Question 6

The heaviest lepton is the

A) proton.
B) electron.
C) neutron.
D) tau.

Question 7

Neutrinos are unique in that they have no charge and almost no

A) mass.
B) spin.
C) photons.
D) antiparticles.

Question 8

The electrical charge of the electron, muon, and tau is

A) $- 1.6 \times 10 ^ { - 19 } \mathrm { C }$
B) $3.2 \times 10 ^ { - 19 } \mathrm { C }$
C) $1.6 \times 10 ^ { - 19 } \mathrm { C } \text {. }$
D) $- 3.2 \times 10 ^ { - 19 } \mathrm { C }$

Question 9

Examples of baryons include

A) protons and neutrons.
B) electrons and muons.
C) neutrinos.
D) taus.

Question 10

Baryons are made from how many quarks?

A) One
B) Four
C) Three
D) Two

Question 11

Mesons are made from how many quarks?

A) One
B) Four
C) Three
D) Two

Question 12

Examples of mesons include

A) electrons and neutrinos.
B) neutrons and protons.
C) protons and electrons.
D) kaons and pions.

Question 13

Baryons always have

A) a +1 charge.
B) no spin.
C) no charge.
D) a half-spin.

Question 14

Particles with half-integer spin are called

A) bosons.
B) fermions.
C) mesons.
D) quarks.

Question 15

Particles with integer values for spin are called

A) bosons.
B) fermions.
C) mesons.
D) quarks.

Question 16

A Feynman diagram is

A) a tool for physicists.
B) a model of the interactions.
C) a graphical representation of the particle exchange process.
D) all of the above.

Question 17

The ? $W ^ { + } , W \text {, and } Z ^ { \circ }$ particles are similar to the photon; but the one difference is that they

A) have mass.
B) have color.
C) have no charge.
D) have no mass.

Question 18

A photon can produce an electron and antielectron pair through the process of

A) quantum tunneling.
B) pair creation.
C) parity violation.
D) CPT invariance.

Question 19

That electricity and magnetism are the same is an example of

A) pair creation.
B) Bhabba scattering.
C) gravitational collapse.
D) a unified field theory.

Question 20

One of the architects in unifying the electromagnetic force with the weak force was

A) Hubble.
B) Weinberg.
C) Gamow.
D) Schwinger.

Question 21

Who was responsible for providing the whimsical name quarks?

A) Gell-Mann
B) Feynman
C) Wheeler
D) Bohr

Question 22

The unique feature of quarks is that

A) they contain fractional charge.
B) they have no mass.
C) they have no charge.
D) they act just like photons.

Question 23

This theory is an attempt to explain the variety of all the known particles:

A) String theory
B) Band theory
C) Turbulence theory
D) Inflation theory

Question 24

The inverse of the Hubble constant provides

A) the age of the Sun.
B) the size of the Sun.
C) the age of the universe.
D) the size of the Milky Way.

Question 25

All of the following properties of a muon and an electron have identical values except

A) charge.
B) mass.
C) spin.
D) Hold it! There are no exceptions.

Question 26

All of the following properties of an antiparticle and its corresponding particle have identical values except

A) charge.
B) mass.
C) spin.
D) Hold it! There are no exceptions.

Question 27

The neutron-proton pair have a magnitude of mass that is

A) the smallest among known baryons.
B) the largest among known baryons.
C) Neither of the first two responses is valid.
D) Hold it! If the property of spin were substituted for mass in the question, one of the first two responses would be valid.

Question 28

Of the following three categories of particles, the only group that contains particles with zero mass is the

A) baryons.
B) mesons.
C) leptons.
D) More than one of the previous responses are valid.

Question 29

Of the following three categories of particles, the only group that contains particles with integral values of spin is the

A) baryons.
B) mesons.
C) leptons.
D) More than one of the previous responses are valid.

Question 30

Of the following three categories of particles, the only group that contains particles with the exclusive value of 1/2 for spin is the

A) baryons.
B) mesons.
C) leptons.
D) None of the previous responses is valid.

Question 31

All of the following conservation laws are absolute except the conservation of

A) angular momentum.
B) baryon number.
C) strangeness.
D) Hold it! There are no exceptions.

Question 32

All of the following conservation laws are absolute except the conservation of

A) energy.
B) charge.
C) momentum.
D) Hold it! There are no exceptions.

Question 33

All of the following conservation laws are approximate except the conservation of

A) isospin.
B) parity.
C) lepton number.
D) Hold it! There are no exceptions.

Question 34

Calling a conservation law approximate means that the relevant quantity is

A) conserved, with a high probability under identical conditions.
B) conserved, within a small percentage under each instance.
C) conserved, under a well-defined set of circumstances.
D) conserved, within the restrictions of the Heisenberg uncertainty relations.

Question 35

An electron-ositron pair can annihilate with the emission of two $\gamma$ -rays. A single (isolated) $\gamma$ -ray cannot disappear with the creation of an electron-positron pair because

A) momentum could not be conserved.
B) energy could not be conserved.
C) angular momentum could not be conserved.
D) Hold it! The premise is wrong: a single (isolated) $\gamma$ -ray can disappear under the circumstances described.

Question 36

The range R of a force field is related to the mass M of the mediating particle (field quantum) by the expression

A) R $\infty$ M.
B) R $\infty$ $\frac { 1 } { M }$
C) R is independent of M.
D) Hold it! A field is smooth and continuous, not quantized.

Question 37

The force field with the smallest range is that associated with

A) electromagnetism.
B) gravity.
C) the strong interaction.
D) the weak interaction.

Question 38

The range of two of the four force fields is infinite, and the range of the other two fields is finite. Therefore, the masses associated with the fields are, respectively,

A) zero, finite.
B) finite, zero.
C) infinite, finite.
D) finite, infinite.

Question 39

A rough rule in elementary particle physics is that, in order of increasing rate of reaction, the relevant forces are

A) weak, strong, electromagnetic.
B) strong, electromagnetic, weak.
C) electromagnetic, weak, strong.
D) Hold it! None of the previous responses is valid.

Question 40

The only group of particles (of the three groups listed in the responses) that is not directly responsive to the strong interaction is

A) baryons.
B) leptons.
C) mesons.
D) Hold it! No such generalization as proposed in the stem of this question is valid.

Question 41

The neutron participates in all of the following interactions except

A) strong.
B) electromagnetic.
C) weak.
D) Hold it! There are no exceptions.

Question 42

Consider two identical particles (with mass ? 0) undergoing a collision with one at rest. As the speed of the other particle increases, the fraction of its energy available for the creation of new particles

A) increases.
B) remains unchanged.
C) decreases.
D) Insufficient information is given for a response that is valid in general.

Question 43

All of the following characteristics are valid for the (hypothetical) color force except

A) it is independent of distance between the relevant force-experiencing particles.
B) it is mediated by gluons.
C) it is the generalized basis for the strong force.
D) Hold it! There are no exceptions.

Question 44

All of the following considerations provide evidence for the proton being a composite particle except

A) high-energy electrons are deflected from the proton as if the proton contains "lumps."
B) high-energy particles have succeeded in fragmenting the proton into its elementary building blocks.
C) the predictive successes of the quark model.
D) Hold it! There are no exceptions.

Question 45

For a bubble chamber to record the passage of a particle, all of the following are requirements except

A) the particle must be charged.
B) the liquid in the chamber must be superheated.
C) the photographs must be taken before the bubbles disperse.
D) Hold it! There are no exceptions.

Question 46

Electrons and photons are related in each of the following ways except

A) accelerating electrons produce photons.
B) virtual photons produce forces between electrons.
C) both particles obey the Pauli Exclusion Principle.
D) Hold it! There are no exceptions.

Question 47

Scientists have been successful in unifying each of the following pairs of concepts except

A) electricity and magnetism.
B) space and time.
C) electromagnetic and weak forces.
D) Hold it! There are no exceptions.

Question 48

The correct listing of the following three categories of particles, in order of increasing number of particles in the groups, is

A) baryons, leptons, mesons.
B) mesons, baryons, leptons.
C) leptons, mesons, baryons.
D) baryons, mesons, leptons.