A particle game.Figure 44-13 is a sketch of the tracks made by particles in a fictionalcloud chamber experiment (with a uniform magnetic field directed perpendicular to the page), and Table 44-6 gives fictionalquantum numbers associated with the particles making the tracks. Particle A entered the chamber at the lower left, leaving track and decaying into three particles. Then the particle creating track 1 decayed into three other particles, and the particle creating track 6 decayed into two other particles, one of which was electrically uncharged—the path of that uncharged particle is represented by the dashed straight line because, being electrically neutral, it would not actually leave a track in a cloud chamber. The particle that created track is known to have a seriousness quantum number of zero.

By conserving the fictional quantum numbers at each decay point and by noting the directions of curvature of the tracks, identify which particle goes with track (a) 1, (b) 2, (c) 3, (d) 4, (e) 5, (f) 6, (g) 7, (h) 8, and (i) 9. One of the listed particles is not formed; the others appear only once each.

Particle

Charge

Whimsy

Seriousness

Cuteness

A

1

1

-2

-2

B

0

4

3

0

C

1

2

-3

-1

D

-1

-1

0

1

E

-1

0

-4

-2

F

1

0

0

0

G

-1

-1

1

-1

H

3

3

1

0

I

0

6

4

6

J

1

-6

-4

-6

Short Answer

Expert verified

(a) The particle corresponding to track 1isA.

(b) The particle corresponding to track 2isJ.

(c) The particle corresponding to track 3isI.

(d) The particle corresponding to track 4isF.

(e) The particle corresponding to track 5isG.

(f) The particle corresponding to track 6isC.

(g) The particle corresponding to track 7isH.

(h) The particle corresponding to track 8isD.

(i) The particle corresponding to track 9isE.

Step by step solution

01

Given data 

Fictional quantum numbers of particles A to J are provided in the given table.

Track 1 corresponds to particle A.

Uncharged particles are dashed lines.

Particle corresponding to track 8 has zero seriousness.

02

Deviation of charged particles in the cloud chamber 

Positive and negatively charged particle deviate in opposite directions in the cloud chamber.

03

Determining the particles corresponding to all the tracks 

It is given that particle A produced track 1. Particle A is positively charged. Thus all tracks deviating left correspond to positively charged particles and all tracks deviating right correspond to negatively charged particles.

There are two particles with zero seriousness in the table, D and F. Track 8 deviates to the right and thus corresponds to a negatively charged particle. Hence

8D

Track 6 corresponds to a positively charged particle that decays to track 7 (positively charged), particle that is negatively charged and track 9 (negatively charged). From the table, this is only possible if the particle causing track has charge and particle corresponding to track 7 has +1 charge. Thus

7H

Track 3 corresponds to an uncharged particle. So it can be either B or I. Tracks 2 and 4 correspond to positively charged particles. If track 3 corresponds to B, cuteness quantum number of B is zero. Hence cuteness quantum numbers of particles producing tracks 2 and 4 should be the same. But none of the remaining positively charged particles have the same cuteness quantum numbers. Thus

3I

Particle I has cuteness 6. The only combination to conserve cuteness in that decay channel is to have cuteness of particle producing track 2 as -6(J) and that of track 4 as 0(F)

Thus

2J4F

The only positively charged particle left in the table is C and track 6 corresponds to a positively charged particle. Thus67

6C

In the decay channel 67+8+9, that is CH+D+9, cuteness of C, H and D are -1,0 and 1 respectively. Thus the cuteness of particle creating track 9 should be 101=2and should be negatively charged. The only negatively charged particle with -2 cuteness is E. Thus9E

Track 5 corresponds to a negatively charged particle and the only negatively charged particle left is G. Thus5G

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Most popular questions from this chapter

Cosmological red shift. The expansion of the universe is often represented with a drawing like Fig. 44-15a. In that figure, we are located at the symbol labeled MW (for the Milky Way galaxy), at the origin of an axis that extends radially away from us in any direction. Other, very distant galaxies are also represented. Superimposed on their symbols are their velocity vectors as inferred from the red shift of the light reaching us from the galaxies. In accord with Hubble’s law, the speed of each galaxy is proportional to its distance from us. Such drawings can be misleading because they imply

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Δλλ=c-

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