Chapter 33

Chapter 33

Problems & Exercises

1.

3 × 10 − 39 s 3 × 10 − 39 s

3.

1 . 99 × 10 − 16 m ( 0 . 2 fm ) 1 . 99 × 10 − 16 m ( 0 . 2 fm )

4.

(a) 10−1110−11 to 1, weak to EM

(b) 1 to 1

6.

(a) 2.09×10−5s2.09×10−5s

(b) 4.77×104Hz4.77×104Hz

8.

78.0 cm

10.

1 . 40 × 10 6 1 . 40 × 10 6

12.

100 GeV

13.

67.5 MeV

15.

(a) 1×10141×1014

(b) 2×10172×1017

17.

(a) 1671 MeV 1671 MeV

(b) Q = 1, Q′ = 1 + 0 + 0 = 1. L τ = − 1; L′τ = − 1; Lμ = 0; L′μ = − 1 + 1 = 0 Q = 1, Q′ = 1 + 0 + 0 = 1. L τ = − 1; L′τ = − 1; Lμ = 0; L′μ = − 1 + 1 = 0

(c) τ − → μ − + v μ + v ¯ τ ⇒ μ −   antiparticle of  μ + ;  v μ   of  v ¯ μ ;  v ¯ τ   of  v τ τ − → μ − + v μ + v ¯ τ ⇒ μ −   antiparticle of  μ + ;  v μ   of  v ¯ μ ;  v ¯ τ   of  v τ

19.

(a) 3.9 eV

(b) 2.9×10−82.9×10−8

21.

(a) The uuduud composition is the same as for a proton.

(b) 3.3×10−24s3.3×10−24s

(c) Strong (short lifetime)

23.

a) Δ++(uuu);B=13+13+13=1Δ++(uuu);B=13+13+13=1

b)

Quark-flow diagram illustrating the formation of a Delta++ (Δ++) baryon from a pion (π+) and a proton (p). The interaction involves a gluon exchange, transforming a d̄ and d quark into a u quark.
25.

(a) +1+1

(b) B=1=1+0,  Z==0+(−1)B=1=1+0,  Z==0+(−1), all lepton numbers are 0 before and after

(c) (sss)→(uds)+u-s(sss)→(uds)+u-s

27.

(a) (uu-+dd¯)→(uu-+dd¯)+(uu-+dd¯)(uu-+dd¯)→(uu-+dd¯)+(uu-+dd¯)

(b) 277.9 MeV

(c) 547.9 MeV

29.

No. Charge=−1Charge=−1 is conserved. Lei=0≠Lef=2Lei=0≠Lef=2 is not conserved. Lμ=1Lμ=1 is conserved.

31.

(a)Yes. Z=−1=0+(−1)Z=−1=0+(−1), B=1=1+0B=1=1+0, all lepton family numbers are 0 before and after, spontaneous since mass greater before reaction.

(b) dds→udd+u-ddds→udd+u-d

33.

(a) 216

(b) There are more baryons observed because we have the 6 antiquarks and various mixtures of quarks (as for the π-meson) as well.

35.

Ω + ( s - s - s - ) B = − 1 3 − 1 3 − 1 3 = − 1, L e , μ , τ = 0 + 0 + 0 = 0, Q = 1 3 + 1 3 + 1 3 = 1, S = 1 + 1 + 1 = 3 . Ω + ( s - s - s - ) B = − 1 3 − 1 3 − 1 3 = − 1, L e , μ , τ = 0 + 0 + 0 = 0, Q = 1 3 + 1 3 + 1 3 = 1, S = 1 + 1 + 1 = 3 .

37.

(a)803 MeV

(b) 938.8 MeV

(c) The annihilation energy of an extra electron is included in the total energy.

39.

c d ¯ c d ¯

41.

a)The antiproton

b) p-→π0+e−p-→π0+e−

43.

(a) 5×10105×1010

(b) 5×104particles/m25×104particles/m2

45.

2.5 × 10 − 17 m 2.5 × 10 − 17 m

47.

(a) 33.9 MeV

(b) Muon antineutrino 29.8 MeV, muon 4.1 MeV (kinetic energy)

49.

(a) 7.2×105kg7.2×105kg

(b) 7.2×102m37.2×102m3

(c) 100 months100 months

53.

(a) 2(1.67× 10 −27  kg)=3.34× 10 −27  kg 2(1.67× 10 −27  kg)=3.34× 10 −27  kg

(b) 3.34× 10 −27 (3.00× 10 8 ) 2  joules=3.01× 10 −10  joules 3.34× 10 −27 (3.00× 10 8 ) 2  joules=3.01× 10 −10  joules

(c) 3.01× 10 −10  joules 3.01× 10 −10  joules

(d) The proton has a positive charge, and the antiproton has a negative charge.

Test Prep for AP® Courses

1.

(d)

3.

(d)

5.

(b)

7.

(a)

9.

(c), though this comes from Einstein's special relativity

11.

(a)

13.

(d)

15.

(b)

17.

(b)