Question 1

The attractive force between protons and neutrons in the nucleus is brought about by the exchange of a virtual pi-meson (m  π\piπ  = 140 MeV/c2) .Estimate the longest time a virtual   π\piπ 0 can exist, in accordance with the uncertainty principle .(1 eV = 1.6 * 10-19 J.)

Accepted Answer

A)  2.4 * 10-24 s
B)  6.9 * 10-27 s
C)  3.3 * 10-18 s
D)  2.4 * 10-21 s
E)  1.6 * 10-19 s F) D) and E)
G) B) and E)

Question 2

The particle  Δ\DeltaΔ ++ has an electric charge twice that of the proton and baryon number +1.Strangeness, charm, bottomness and topness are all 0.Its quark composition must be:

Accepted Answer

A)  uuu.
B)  uud.
C)  udd.
D)    udd‾u \overline{d d}udd 
E)    ddd‾\overline{d d d}dddF) A) and C)
G) A) and B)

Question 3

The minimum energy needed to produce a positron is:

Accepted Answer

A)  3 MeV
B)  2 MeV
C)  1 MeV
D)  4 MeV
E)  0.51 MeVF) A) and E)
G) A) and D)

Question 4

Particles composed of quarks are:

Accepted Answer

A)  photons.
B)  leptons.
C)  neutrinos.
D)  W and Z bosons.
E)  baryons and mesons.F) B) and D)
G) A) and E)

Question 5

Name at least one conservation law that prevents each of the following reactions:
a) $\pi$- + p $\rightarrow$ $\Sigma$+ +  $\pi$$\degree$
b)p$\rightarrow$  $\pi$+ +  $\pi$+ +  $\pi$-

Accepted Answer

a) charge,...

Question 6

A  Σ\SigmaΣ + particle, composed of uus quarks, has the same ____ as a proton.

Accepted Answer

A)  baryon number and charm.
B)  baryon number and electric charge.
C)  baryon number and strangeness.
D)  baryon number, electric charge, and charm.
E)  electric charge and strangeness. F) B) and C)
G) B) and E)

Question 7

According to the Hubble law, where H = 17 km/s/106 light-years, what is the velocity of recession of a quasar at a distance of 2 billion light-years from Earth?

Accepted Answer

A)  0.75 c
B)  0.33 c
C)  0.55 c
D)  0.11 c
E)  0.93 cF) B) and D)
G) B) and C)

Question 8

A proton and an antiproton each with total energy of 400 GeV collide head-on.What is the total energy (particles + energy)  released?

Accepted Answer

A)  zero
B)  400 Gev
C)  800 GeV
D)  1600 GeV
E)  2400 GeVF) C) and D)
G) All of the above

Question 9

A K0 particle at rest decays into a $\pi$+ and a  $\pi$-.What will be the speed of each of the pions? The mass of the K0 is 497.7 MeV/c2 and the mass of each $\pi$ is 139.6 MeV/c2.

Accepted Answer

The answer of A K0 particle at rest decays into...

Question 10

The decay is not possible because:

Accepted Answer

A)  Le is not conserved.
B)  L μ\muμ  is not conserved.
C)  quark number is not conserved.
D)  all of the above are not conserved.
E)  only Le and L μ\muμ are not conserved. F) A) and B)
G) B) and D)

Question 11

A model for how repulsive forces between two particles can be mediated by a third particle would be:

Accepted Answer

A)  a person on a skateboard pushing against a wall.
B)  two people in two canoes throwing a ball back and forth.
C)  two people in two canoes each pulling on one end of a rope.
D)  two people in two skateboards giving each other a shove.
E)  two people in two skateboards each pulling on one end of a rope.F) D) and E)
G) A) and E)

Question 12

If a K0 meson at rest decays in 0.89 *10-10 s, how far will a K0 meson moving at 0.96 c travel through a bubble chamber?

Accepted Answer

A)  17 cm
B)  1.1 cm
C)  53 cm
D)  42 mm
E)  9.2 cmF) A) and B)
G) C) and E) E

Question 13

Calculate the range of the force that might be produced by the virtual exchange of a proton.(mp = 1.67 *10-27 kg, h = 6.626 * 10-34 J . s)

Accepted Answer

The answer of Calculate the range of the force that...

Question 14

Which of the following reactions cannot occur?

Accepted Answer

A)   n→p+e−+vˉe \mathrm{n} \rightarrow \mathrm{p}+\mathrm{e}^{-}+\bar{v}_{e} n→p+e−+vˉe​ 
B)   p+n→p+p+p‾ \mathrm{p}+\mathrm{n} \rightarrow \mathrm{p}+\mathrm{p}+\overline{\mathrm{p}} p+n→p+p+p​ 
C)   μ−→e−+vˉe+vμ\mu^{-} \rightarrow \mathrm{e}^{-}+\bar{v}_{e}+v_{\mu}μ−→e−+vˉe​+vμ​  
D)   πˉ→μˉ+vμ\bar{\pi} \rightarrow \bar{\mu}+v_{\mu}πˉ→μˉ​+vμ​ 
E)   π+→μ++vˉμ\pi^{+} \rightarrow \mu^{+}+\bar{v}_{\mu}π+→μ++vˉμ​F) C) and D)
G) None of the above B

Question 15

The acceleration (or deceleration)  of the expansion of the universe is determined by:

Accepted Answer

A)  the standard matter, baryons and leptons.
B)  the dark matter in the universe.
C)  the dark energy in the universe.
D)  all of the above.
E)  only (b)  and (c)  above.F) A) and B)
G) D) and E)

Question 16

All particles can be classified into:

Accepted Answer

A)  leptons and quarks.
B)  hadrons and leptons.
C)  baryons and leptons.
D)  mesons and baryons.E) C) and D)
F) All of the above

Question 17

The following reaction can occur by the strong interaction:   π\piπ 0 + n  →\rightarrow→   K+ +  Σ\SigmaΣ -.If the quark composition of the n is (udd) , the  π\piπ°\degree°  is () , and the composition of the K+ is () , find the quark composition of the  Σ\SigmaΣ -.

Accepted Answer

A)  sss
B)  uds
C)  dds
D)    ddsˉd d \bar{s}ddsˉ 
E)    u‾ s\overline{\mathrm{u}} \mathrm{~s}u sF) A) and C)
G) B) and C)

Question 18

In this course we have seen that baryons have inertial and gravitational mass, intrinsic angular momentum, and other internal properties that have been given names like baryon number, strangeness, charm, etc.The Standard Model's explanation for these properties of baryons is that:

Accepted Answer

A)  the baryons are states of something more elementary that can exist in multiple quantum states.
B)  the leptons are states of something more elementary that can exist in multiple quantum states.
C)  photons are states of something more elementary that can exist in multiple quantum states.
D)  according to the Heisenberg Uncertainty Principle quantum numbers are indeterminate.
E)  quarks are states of something more elementary that can exist in multiple quantum states.F) B) and C)
G) D) and E) A

Question 19

The law of conservation of baryon number is that:

Accepted Answer

A)  the total number of baryons and leptons is conserved.
B)  the total number of baryons is conserved.
C)  the (number of baryons)  - (number of antibaryons)  is conserved.
D)  the total number of quarks is conserved.
E)  the (number of baryons)  + (number of antibaryons)  is conserved.F) A) and B)
G) A) and C)

Question 20

The strong nuclear interaction has a range of approximately 0.70 * 10-15 m.It is thought that an elementary particle is exchanged between the protons and neutrons, leading to an attractive force.Utilise the uncertainty principle to estimate the mass of the elementary particle if it moves at nearly the speed of light.  ΔEΔt=h/2\Delta E \Delta t=h / 2ΔEΔt=h/2

Accepted Answer

A)  140 MeV/c2, a pion
B)  511 keV/c2, an electron
C)  96 GeV/c2, a Z boson
D)  500 MeV/c2, a K meson
E)  106 MeV/c2, a muon F) A) and E)
G) C) and E)

Exam 22: Particle Physics

Correct Answer
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The particle $\Delta$ ++ has an electric charge twice that of the proton and baryon number +1.Strangeness, charm, bottomness and topness are all 0.Its quark composition must be:

Correct Answer
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The minimum energy needed to produce a positron is:

Correct Answer
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Particles composed of quarks are:

Correct Answer
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Name at least one conservation law that prevents each of the following reactions: a) $\pi$ - + p $\rightarrow$ $\Sigma$ + + $\pi$ $\degree$ b)p $\rightarrow$ $\pi$ + + $\pi$ + + $\pi$ -

Correct Answer
verified
a) charge,...
View Answer

A $\Sigma$ + particle, composed of uus quarks, has the same ____ as a proton.

Correct Answer
verified

According to the Hubble law, where H = 17 km/s/106 light-years, what is the velocity of recession of a quasar at a distance of 2 billion light-years from Earth?

Correct Answer
verified

A proton and an antiproton each with total energy of 400 GeV collide head-on.What is the total energy (particles + energy) released?

Correct Answer
verified

A K0 particle at rest decays into a $\pi$ + and a $\pi$ -.What will be the speed of each of the pions? The mass of the K0 is 497.7 MeV/c2 and the mass of each $\pi$ is 139.6 MeV/c2.

Correct Answer
verified

The decay is not possible because: $The decay is not possible because: A) Le is not conserved. B) L \mu is not conserved. C) quark number is not conserved. D) all of the above are not conserved. E) only Le and L \mu are not conserved.$

Correct Answer
verified

A model for how repulsive forces between two particles can be mediated by a third particle would be:

Correct Answer
verified

If a K0 meson at rest decays in 0.89 *10-10 s, how far will a K0 meson moving at 0.96 c travel through a bubble chamber?

Correct Answer
verified
E

Calculate the range of the force that might be produced by the virtual exchange of a proton.(mp = 1.67 10-27 kg, h = 6.626 10-34 J . s)

Correct Answer
verified

Which of the following reactions cannot occur?

Correct Answer
verified
B

The acceleration (or deceleration) of the expansion of the universe is determined by:

Correct Answer
verified

All particles can be classified into:

Correct Answer
verified

Correct Answer
verified

In this course we have seen that baryons have inertial and gravitational mass, intrinsic angular momentum, and other internal properties that have been given names like baryon number, strangeness, charm, etc.The Standard Model's explanation for these properties of baryons is that:

Correct Answer
verified
A

The law of conservation of baryon number is that:

Correct Answer
verified

Correct Answer
verified

Exam 22: Particle Physics

The attractive force between protons and neutrons in the nucleus is brought about by the exchange of a virtual pi-meson (m π\piπ = 140 MeV/c2) .Estimate the longest time a virtual π\piπ 0 can exist, in accordance with the uncertainty principle .(1 eV = 1.6 * 10-19 J.)

Correct AnswerverifiedShow Answer

The particle Δ\DeltaΔ ++ has an electric charge twice that of the proton and baryon number +1.Strangeness, charm, bottomness and topness are all 0.Its quark composition must be:

Correct AnswerverifiedShow Answer

The minimum energy needed to produce a positron is:

Correct AnswerverifiedShow Answer

Particles composed of quarks are:

Correct AnswerverifiedShow Answer

Name at least one conservation law that prevents each of the following reactions: a) π\piπ - + p →\rightarrow→ Σ\SigmaΣ + + π\piπ°\degree° b)p →\rightarrow→ π\piπ + + π\piπ + + π\piπ -

Correct Answerverifieda) charge,...View AnswerShow Answer

A Σ\SigmaΣ + particle, composed of uus quarks, has the same ____ as a proton.

Correct AnswerverifiedShow Answer

According to the Hubble law, where H = 17 km/s/106 light-years, what is the velocity of recession of a quasar at a distance of 2 billion light-years from Earth?

Correct AnswerverifiedShow Answer

A proton and an antiproton each with total energy of 400 GeV collide head-on.What is the total energy (particles + energy) released?

Correct AnswerverifiedShow Answer

A K0 particle at rest decays into a π\piπ + and a π\piπ -.What will be the speed of each of the pions? The mass of the K0 is 497.7 MeV/c2 and the mass of each π\piπ is 139.6 MeV/c2.

Correct AnswerverifiedShow Answer

The decay is not possible because:

Correct AnswerverifiedShow Answer

A model for how repulsive forces between two particles can be mediated by a third particle would be:

Correct AnswerverifiedShow Answer

If a K0 meson at rest decays in 0.89 *10-10 s, how far will a K0 meson moving at 0.96 c travel through a bubble chamber?

Correct AnswerverifiedE

Calculate the range of the force that might be produced by the virtual exchange of a proton.(mp = 1.67 *10-27 kg, h = 6.626 * 10-34 J . s)

Correct AnswerverifiedShow Answer

Which of the following reactions cannot occur?

Correct AnswerverifiedB

The acceleration (or deceleration) of the expansion of the universe is determined by:

Correct AnswerverifiedShow Answer

All particles can be classified into:

Correct AnswerverifiedShow Answer

The following reaction can occur by the strong interaction: π\piπ 0 + n →\rightarrow→ K+ + Σ\SigmaΣ -.If the quark composition of the n is (udd) , the π\piπ°\degree° is () , and the composition of the K+ is () , find the quark composition of the Σ\SigmaΣ -.

Correct AnswerverifiedShow Answer

In this course we have seen that baryons have inertial and gravitational mass, intrinsic angular momentum, and other internal properties that have been given names like baryon number, strangeness, charm, etc.The Standard Model's explanation for these properties of baryons is that:

Correct AnswerverifiedA

The law of conservation of baryon number is that:

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct Answer
verified

The particle $\Delta$ ++ has an electric charge twice that of the proton and baryon number +1.Strangeness, charm, bottomness and topness are all 0.Its quark composition must be:

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Name at least one conservation law that prevents each of the following reactions: a) $\pi$ - + p $\rightarrow$ $\Sigma$ + + $\pi$ $\degree$ b)p $\rightarrow$ $\pi$ + + $\pi$ + + $\pi$ -

Correct Answer
verified
a) charge,...
View Answer

A $\Sigma$ + particle, composed of uus quarks, has the same ____ as a proton.

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

A K0 particle at rest decays into a $\pi$ + and a $\pi$ -.What will be the speed of each of the pions? The mass of the K0 is 497.7 MeV/c2 and the mass of each $\pi$ is 139.6 MeV/c2.

Correct Answer
verified

The decay is not possible because: $The decay is not possible because: A) Le is not conserved. B) L \mu is not conserved. C) quark number is not conserved. D) all of the above are not conserved. E) only Le and L \mu are not conserved.$

Correct Answer
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Correct Answer
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Correct Answer
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E

Calculate the range of the force that might be produced by the virtual exchange of a proton.(mp = 1.67 10-27 kg, h = 6.626 10-34 J . s)

Correct Answer
verified

Correct Answer
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B

Correct Answer
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Correct Answer
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Correct Answer
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A

Correct Answer
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Correct Answer
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