Question 1

Not counting antiparticles, how many different leptons are there?

Accepted Answer

A)   2
B)   4
C)   6
D)   8
E)   10 C

Question 2

Which of the following particles interact via the strong interaction?

Accepted Answer

A)   gravitons
B)   quarks
C)   leptons
D)   neutrinos
E)   photons B

Question 3

In addition to charge and baryon number, another conserved quantity in particle interactions is lepton number. The six leptons have lepton number +1, and their antiparticles have lepton number −1. The lepton numbers for each generation (electron, muon, tau) are separately conserved. For example, an electron has electron-lepton number +1, while the electron antineutrino has electron-lepton number −1. What is the missing particle X in the following reaction? μ−+ p → n + X

Accepted Answer

A)   e−
B)   π0
C)   ve
D)   vμ
E)   γ D

Question 4

The weak interaction is mediated by

Accepted Answer

A)   gluon.
B)   photon.
C)   mesons.
D)   W+, W−, Z0.
E)   leptons.

Question 5

One way to estimate the range of an interaction is by using the Heisenberg uncertainty principle. Assume that the uncertainty in the energy of an exchange particle is given by its rest energy and that the particle travels at nearly the speed of light. Under those assumptions, what is the approximate range of the weak interaction mediated by the Z0 particle, which has a mass of 91.2 GeV/c2?

Accepted Answer

A)   10−15 m
B)   10−18 m
C)   10−21 m
D)   10−24 m
E)   10−27 m

Question 6

Which of the following is not an abbreviation for a quark flavor?

Accepted Answer

A)   u
B)   s
C)   b
D)   t
E)   r

Question 7

Which of the conservation laws listed below would definitely be violated in the following reaction? π+ + p → p + π−?

Accepted Answer

A)   baryon number
B)   energy
C)   momentum
D)   charge

Question 8

An electron and a positron, each having kinetic energy 1.843 GeV, collide head-on and annihilate, producing a proton and antiproton pair (M = 938.3 MeV/c2). What is the kinetic energy of the antiproton produced in this way?

Accepted Answer

A)   0.938 GeV.
B)   0.905 GeV.
C)   1.586 GeV.
D)   1.843 GeV.

Question 9

Which of the fundamental interactions governs the following decay? π+ → e+ + ve?

Accepted Answer

A)   strong nuclear
B)   electromagnetic
C)   gravitational
D)   weak nuclear

Question 10

Arrange the strong (S), electromagnetic (EM), weak (W), and gravitational (G) forces from weakest to strongest.

Accepted Answer

A)   W, G, EM, S
B)   W, G, S, EM
C)   G, W, S, EM
D)   G, W, EM, S
E)   W, S, G, EM

Question 11

Which of the fundamental interactions governs the following decay? πo → y + y

Accepted Answer

A)   weak nuclear
B)   electromagnetic
C)   gravitational
D)   strong nuclear

Question 12

Gluons can absorb and emit

Accepted Answer

A)   electrons.
B)   protons.
C)   photons.
D)   baryons.
E)   gluons.

Question 13

Baryons are composed of

Accepted Answer

A)   any odd number of quarks.
B)   three quarks of matching color.
C)   three quarks of three different colors.
D)   a colorless quark-antiquark pair.

Question 14

Who is credited with first speculating that matter is composed of tiny unseen units?

Accepted Answer

A)   Democritus
B)   Aristarchus
C)   Aristotle
D)   Newton
E)   Einstein

Question 15

The electron antineutrino is which of the following types of particle?

Accepted Answer

A)   meson
B)   baryon
C)   hadron
D)   lepton
E)   quark

Question 16

A bound quark-antiquark pair is called a

Accepted Answer

A)   proton.
B)   neutron.
C)   meson.
D)   baryon.
E)   lepton.

Question 17

The exchange particle that mediates the strong interaction is the

Accepted Answer

A)   gluon.
B)   photon.
C)   graviton.
D)   neutrino.

Question 18

In brane-world theory, there are extra

Accepted Answer

A)   strings.
B)   gluons.
C)   monopoles.
D)   dimensions.
E)   leptons.

Question 19

In an accelerator, two protons collide head-on and the following reaction takes place: p + p → p + p + π0. What is the minimum kinetic energy of each initial proton for this reaction to occur? The mass of the proton is 938 MeV/c2 and the mass of the neutral pion is 135 MeV/c2.

Accepted Answer

A)   938 MeV
B)   187 MeV
C)   135 MeV
D)   67.5 MeV
E)   0 MeV

Question 20

Isolated quarks were first observed in

Accepted Answer

A)   1938.
B)   1955.
C)   1976.
D)   2012, with the discovery of the Higgs boson.
E)   Isolated quarks have not been observed.

Exam 30: Particle Physics

Not counting antiparticles, how many different leptons are there?

Which of the following particles interact via the strong interaction?

The weak interaction is mediated by

Which of the following is not an abbreviation for a quark flavor?

Which of the conservation laws listed below would definitely be violated in the following reaction? π⁺ + p → p + π⁻?

An electron and a positron, each having kinetic energy 1.843 GeV, collide head-on and annihilate, producing a proton and antiproton pair (M = 938.3 MeV/c²) . What is the kinetic energy of the antiproton produced in this way?

Which of the fundamental interactions governs the following decay? π⁺ → e⁺ + v_e?

Arrange the strong (S) , electromagnetic (EM) , weak (W) , and gravitational (G) forces from weakest to strongest.

Which of the fundamental interactions governs the following decay? π^o → y + y

Gluons can absorb and emit

Baryons are composed of

Who is credited with first speculating that matter is composed of tiny unseen units?

The electron antineutrino is which of the following types of particle?

A bound quark-antiquark pair is called a

The exchange particle that mediates the strong interaction is the

In brane-world theory, there are extra

In an accelerator, two protons collide head-on and the following reaction takes place: p + p → p + p + π⁰. What is the minimum kinetic energy of each initial proton for this reaction to occur? The mass of the proton is 938 MeV/c² and the mass of the neutral pion is 135 MeV/c².

Isolated quarks were first observed in

Exam 30: Particle Physics

Not counting antiparticles, how many different leptons are there?

Which of the following particles interact via the strong interaction?

The weak interaction is mediated by

Which of the following is not an abbreviation for a quark flavor?

Which of the conservation laws listed below would definitely be violated in the following reaction? π+ + p → p + π−?

An electron and a positron, each having kinetic energy 1.843 GeV, collide head-on and annihilate, producing a proton and antiproton pair (M = 938.3 MeV/c2) . What is the kinetic energy of the antiproton produced in this way?

Which of the fundamental interactions governs the following decay? π+ → e+ + ve?

Arrange the strong (S) , electromagnetic (EM) , weak (W) , and gravitational (G) forces from weakest to strongest.

Which of the fundamental interactions governs the following decay? πo → y + y

Gluons can absorb and emit

Baryons are composed of

Who is credited with first speculating that matter is composed of tiny unseen units?

The electron antineutrino is which of the following types of particle?

A bound quark-antiquark pair is called a

The exchange particle that mediates the strong interaction is the

In brane-world theory, there are extra

In an accelerator, two protons collide head-on and the following reaction takes place: p + p → p + p + π0. What is the minimum kinetic energy of each initial proton for this reaction to occur? The mass of the proton is 938 MeV/c2 and the mass of the neutral pion is 135 MeV/c2.

Isolated quarks were first observed in

Which of the conservation laws listed below would definitely be violated in the following reaction? π⁺ + p → p + π⁻?

An electron and a positron, each having kinetic energy 1.843 GeV, collide head-on and annihilate, producing a proton and antiproton pair (M = 938.3 MeV/c²) . What is the kinetic energy of the antiproton produced in this way?

Which of the fundamental interactions governs the following decay? π⁺ → e⁺ + v_e?

Which of the fundamental interactions governs the following decay? π^o → y + y

In an accelerator, two protons collide head-on and the following reaction takes place: p + p → p + p + π⁰. What is the minimum kinetic energy of each initial proton for this reaction to occur? The mass of the proton is 938 MeV/c² and the mass of the neutral pion is 135 MeV/c².