Give a reaction between two nucleons, similar to Eq. 32-4, tea1s de+dw2bui .n;(t hat could produce a u.i bn2e;a (sw+detd1$\pi^0$.

  If a proton is moving at very high speed, so that its rndp z s7;2i 8ed6am2)uko:k0 rbrda sv( 6qy+kinetic energy is much greater than its rest ek;b qn26):az8 rdrsedi0arykm (o v7+2 ps6 udnergy ($mc^2$), can it then decay via $p \to n + \pi^+$?  ----待选择----yesno 

What would an "antiatom," made up of the antiparticles to the constituentahmla o5 .) sm3cif(bd bpg-8k q+hf9-s of normal atoms, consist of? What might happen if anfishlmd-qc a3(ph8 . f)9o-m 5kba+b gtimatter, made of such antiatoms, came in contact with our normal world of matter?

What particle in a decay signals the electromagnetic interact2a9d1vj5 vn2zir mc2h ion?

Does the presence of+-c9ce ( pofkk a neutrino among the decay products of a particle necessarily mean that thee9c(f+kpk-o c decay occurs via the weak interaction? Do all decays via the weak interaction produce a neutrino? Explain.

Why is it that a neutron decays via. .dtnwdd cw7g-a1xn+ the weak interaction even though the neutron and one of its decay products (proton) are strongly interacting?cg- .1ddwxn+. nwd a7t

Which of the four interactions (strome:a1 z9tzvrz 2,js/png, electromagnetic, weak, gravitational) does an electron 2: e/91zajtzvp sr ,mztake part in? A neutrino? A proton?

Check that charge and baryon numbe1(a v5zwem ugnwbg5 m(7qo (/fr are conserved in each of the decays in Table 32-2 nmgqz 1/ mvww(5ug(5b(eo f7a.

Which of the particle decays in Table 32-2 occur via the electromagnetic interacxc+92gl1wipj 1r it+e tion?tej+p i+1i21glrx c w9

Which of the particle decays in Table 32-2 occur by the weak intjx.kom wl5 mazumtz5u z9n960w 1/c7qeraction?

By what interaction, and whygv7-( qa qo:+iuh 34pg8yxcvp, does $\Sigma^0$ decay to $\Lambda^0 + \gamma$? What about $\Xi^-$ decaying to $\Lambda^0 + \pi^-$?

The $\Delta$ baryon has spin $\frac{3}{2}$, baryon number 1, and charge states $Q = +2, +1, 0, -1$. Why is there no charge state $Q = -2$?

Which of the particle decays in Tablxpqrqf 97wq.2e 32-4 occur via the electromagnetic interact f9w xqpqr2q.7ion?

Which of the particle decays in Table 32-4 occur by the weak int cro92vsl yo;h+*x9lneraction?

Quarks have spin $\frac{1}{2}$. How do you account for the fact that baryons have spin $\frac{1}{2}$ or $\frac{3}{2}$, and mesons have spin 0 or 1?

Suppose there were a kind of "neutrinolet" ue1if v-9:y ihaaqn,8that was massless, had no color charge or electrical charge, and did not feel the weaka vh,e9i8 nfqi: u-ay1 force. Could you say that this particle even exists?

  Is it possible for a particle to bes ,5lak9r-pn8lu g x5e both
(a) a lepton and a baryon?  ----待选择----yesno 
(b) a baryon and a hadron? ----待选择----yesno 
(c) a meson and a quark? ----待选择----yesno 
(d) a hadron and a lepton?  ----待选择----yesno 
Explain.

Using the ideas of quantum chromodynamics, would it be possibbpli9nxtv v6o) p )35ile to find particles made up of tvvlppiibo6 n 9)5t)x3wo quarks and no antiquarks? What about two quarks and two antiquarks?

Why do neutrons decay when they are free but not when they are inside the nucm1;q p xpt,wm:-r kl/tleus? pmpttx-mk/1 lr;:w ,q

  Is the reaction $e^- + p \to n + \nu_e$ possible? Explain.  ----待选择----yesno 

Occasionally, the $\pi^+$ will decay by the following reaction: $\pi^+ \to e^+ + \nu_e$. Which of the four forces in nature is responsible for this decay? How do you know?

  What is the total energy of a proton whose kinetic energy is 6.35 99crn mthx.w :GeV?    GeV

  Calculate the wavele,fw05z j ;f y)qj-ohblngth of 35-GeV electrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cycloo.bj),3 *ndb j-y bpiotron in which protons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one complete revosbwtr,*p7v) j 8vqn. f veu+*hnze2(l.uvu0alution for a very high-energy proton in the 1.0-km-rqz7u u8luw,v nrs )btp e(fae+.0*nv2.v* jhv adius Fermilab accelerator? T =     $ \times 10^{-5}\ \text{s}$

  If $\alpha$ particles are accelerated by the cyclotron of Example 32-2, what must be the frequency of the voltage applied to the dees? $f$ =    $ \times 10^7\ \text{Hz}$

  (a) If the cyclotron of Example 32trse3.9cpp3aa8*xj g -2 accelerated $\alpha$ particles, what maximum energy could they attain? What would their speed be? KE =    v =    $ \times 10^7\ \text{m/s}$
(b) Repeat for deuterons ($^2\text{H}$).KE =    v =    $ \times 10^7\ \text{m/s}$
(c) In each case, what frequency of voltage is required? $f$ =    Hz

  Which is better for picking out details of the nucleus: 30-MeV alpl(xds4/mr 7 q* ajd6awha particles or 30-MeV protons? Compare each of their wavelengths ww/a qs7 a(l 6*mj4rxddith the size of a nucleon in a nucleus.  ----待选择---- alpha particles protons 

  The voltage across the o d1wj y)m 7c9q:+bprddees of a cyclotron is 55 kV. How many revolutions do protons make to reach a kinetic ene+:9 y7jq bwr dd1mcop)rgy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelength 6dvhapysaf yz5 j5o4p18wf),($\lambda$, maximum resolvable distance) of 7.0-TeV protons? E =    $\times 10^{-19}\ \text{m}$

  A cyclotron with a radius of 1.0 m is to acc .gmd n:qmr6qzh :u:;8vda:mfelerate deuterons ($^2\text{H}$, mass $= 2.014$ u) to an energy of 12 MeV.
(a) What is the required magnetic field?$\approx $    T
(b) What frequency is needed for the voltage between the dees?$\simeq $    Hz
(c) If the potential difference between the dees averages 22 kV, how many revolutions will the particles make before exiting?$\approx$    $\ \text{revolutions}$
(d) How much time does it take for one deuteron to go from start to exit? $\Delta t$ =    $ \times 10^{-6}\ \text{s}$
(e) Estimate how far it travels during this time. distance =    m

  The 4.25-km-radius tunnel that will be used to ho-fbg fwd a bf7q,849npuse the magnets for the Large Hadron Collider (LHC) calls for protfqffwa- 9bpg7db 84n, on beams of energy 7.0 TeV. What magnetic field will be required? B =    T

  The 1.0-km radius Fermilab Tevatron takes about 20 seconds 8)6jqu:y7uhu vavo rd 1 .,evrto bring the energies of the stored protons from 150 GeV to 1.0 TeV. The acceleration is done once per turn. Estimate the energy given to the protons on each turn. (Yo)uh 8 rr,ueuda.oj vvyv 6:q71u can assume that the speed of the protons is essentially $c$ the whole time.) Energy/revolution =    MeV/rev

Show that the energy of a particle 3 gu+grbe1d sy2/+acr (charge $e$) in a synchrotron, in the relativistic limit ($v \approx c$), is given by $E\ (\text{in eV}) = Brc$, where $B$ is magnetic field strength and $r$ the radius of the orbit (SI units).

  What magnetic field intensity is neyw9+ q+lxoamsx5 f ;l/eded at the 1.0-km-radius Fermilab synchrotron for 1.0aw5q9x+lsm; fxl+oy/-TeV protons? B =    T

  How much energy is released in the3:e)hm9 u izeo0k ojg 74r-pkm decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is released wheg16htec zddh--xp9 ;h h tka+;n a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is required to produce a noxsg2 k. -y(-web5zhj eutron-antineutron pair?    MeV

  Estimate the range of 3i2pf,b*h0f lsx o j)ethe strong force if the mediating particle were the kaon instead of the pion. jbh pf*o,x l)s0ef i23 $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equal speeds. What minimum khlu)gzp zpvx 0/8bdx-h 943dlinetic energy mustv/h 0b3zl84l hxp9dzp)-dgu x each have if a $\pi^0$ meson is to be created in the process? (See Table 32-2.)    MeV

  What minimum kinetic energy must two neull/o02l/ y; )ajspbp btrons each have if they are traveling at the same sj po l bl//p)al;y2s0bpeed toward each other, collide, and produce a $\pi^0$ pair in addition to themselves? (See Table 32-2.)    MeV

  Estimate the range of the weak force using Eq. avz8y-d9w:n9*f6ok r djqs*s 32-3, given the masses of the W and Z partov9j-nzsw :d9sfqrk*dy 8* 6aicles as about 80 to $90\ \text{GeV}/c^2$. $mc^2$$\approx $    $\times 10^{-18}\ \text{m}$

  What are the wavelengths of the two photons produced when a z/hu2 2kzv 1*vklgjb8 proton and antiproton at rest l/gjb2 h21zv8zk*kvuannihilate? $2m_0c^2$$\approx $    $ \times 10^{-15}\ \text{m}$

The $\Lambda^0$ cannot decay by the following reactions. What conservation law is violated in each of the reactions?
(a) $\Lambda^0 \to n + \pi^0$
(b) $\Lambda^0 \to p + K^-$
(c) $\Lambda^0 \to \pi^+ + \pi^-$

  For the decay $\Lambda^0 \to p + \pi^-$, calculate (a) the Q-value (energy released),Q=    MeV
(b) the kinetic energy of the p and $\pi^-$ assuming the $\Lambda^0$ decays from rest. (Use relativistic formulas.)
$KE_p$ =    MeV
$\text{KE}_{\pi^-}$ =    MeV

Show, by conserving momentum and energy, that it is impossible for an isolatj)4 (b9jnk/b wb.aopp ed electron to radiate only a single photon. (b) With this result in mind, how cb /p9 (.w)oa4kbjpn jban you defend the photon exchange diagram in (Fig. Below)?

  What would be the wavelengths of the two photons produced when an e fq9hn fycf1/3u+8 zszlectron and a positron, each with 420 ke/ 1c+u9f fz8qs3nzhfyV of kinetic energy, annihilate head on? $\lambda $ $\approx $    $ \times 10^{-12}\ \text{m}$

  In the rare decay $\pi^+ \to e^+ + \nu_e$, what is the kinetic energy of the positron? Assume the $\pi^+$ decays from rest. $\text{KE}_{\text{e}^-}$ =    MeV

Which of the following reactions and decays are possible? For those forbidden, emk0zxi5,o v;fshb;j:hq y; /xxplain wkh hx0;vs:/m;qfo y,zb x ;5ijhat laws are violated.
(a) $\pi^- + p \to n + \pi^0$
(b) $p \to e^+ + \nu_e$
(c) $p + p \to p + e^+ + \pi^+$
(d) $\pi^- \to e^- + \bar{\nu}_e$
(e) $\mu^+ \to e^+ + \nu_\mu$
(f) $p \to n + e^+ + \nu_e$

  Calculate the kinetic enerh)fz*akzzhc n;df(w, : dw9z 9gy of each of the two products in the decay $\Xi^- \to \Lambda^0 + \pi^-$. Assume the $\Xi^-$ decays from rest.
$\text{KE}_{\Lambda^0}$   MeV
$\text{KE}_{\pi^-}$   MeV

  Could a $\pi^+$ meson be produced if a 100-MeV proton struck a proton at rest? What minimum kinetic energy must the incoming proton have? $\text{KE}_{\pi^-}$ =    MeV

  Calculate the maximum kinetic enlxj -iu0e7cr,ergy of the electron in the decay $\mu^- \to e^- + \bar{\nu}_e + \nu_\mu$. [Hint: In what direction do the two neutrinos move relative to the electron in order to give the latter the maximum kinetic energy? Both energy and momentum are conserved; use relativistic formulas.] $\text{KE}_{\text{e}^-}$    MeV

  Use (Fig. Below) to estimate the energy width and then the lifetimer mo. v9sjn1 +h3etyojtjg1wd9-2ia, of the $\Delta$ resonance using the uncertainty principle.
$\Delta E$ =    MeV
$\Delta t$=    $ \times 10^{-24}\ \text{s}$

  The measured width of:8a:r)2 b f -mqfnyrwk the $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width of tv3 n*tcci+ qz*he $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy widthrw50 r /cdwmi: (or uncertainty) of
(a) $\pi^0$, $\Delta E$$\approx$    keV
(b) $\Sigma^0$? (See Table 32-2.) $\Delta E$$\approx$    keV

The $B^-$ meson is a $b\bar{u}$ quark combination. (a) Show that this is consistent for all quantum numbers. (b) What are the quark combinations for $B^+$, $B^0$, $\bar{B}^0$?

Which of the following decays are possible? For those that are forb m v8r0h)-pg uqm2ma;lidden, explain which laws almv0)q hp r;ugm-82mare violated.
(a) $\Xi^0 \to \Sigma^+ + \pi^-$
(b) $\Omega^- \to \Sigma^+ + \pi^- + \nu$
(c) $\Sigma^0 \to \Delta^0 + \gamma + \gamma$

What are the quark combinations that can form (a) a ne, htjpw:s ,z-gutron, (b) an antineutron, tsg,zwjhp ,-: (c) a $\pi^+$, (d) a $K^-$?

What particles do the followindpb 9 mzaxdw:tyj1 )0y92)a big quark combinations produce: (a) $uud$, (b) $uu\bar{d}$, (c) $u\bar{s}$, (d) $\bar{d}u$, (e) $c\bar{s}$?

What is the quark combination needed7(tqu b w2aasc0q+f,b to produce a $D^+$ meson ($Q=B=S=0, c=+1$)?

The $D_s^+$ meson has $S=c=+1, B=0$. What quark combination would produce it?

Draw a possible Feynman diagram using q) vsdt5g2)jgquarks (as in Fig. Below) for the reaction gt) jv)s2d gq5$p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for the reaction / wbq- wold*9zf+zg. y$n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a proton whose kinetic energy is 25 GeV? Wh r6bk5n8moqg n+f420t6sov ll at is its wavelength? 0qo mo5rln68 k gstln+v4f26b
$\approx$    $ \ \text{GeV}$
$\lambda$ $= $    $ \times 10^{-17}\ \text{m}$

  Assume there are $5.0 \times 10^{13}$ protons at 1.0 TeV stored in the 1.0-km-radius ring of the Tevatron.
(a) How much current (amperes) is carried by this beam?I =    A
(b) How fast would a 1500-kg car have to move to carry the same kinetic energy as this beam? v $\approx $    $ \times 10^2\ \text{m/s}$

  Protons are injected 2cgo8g h3mf, 1nyj bg*into the 1.0-km-radius Fermilab Tevatron with an energy of 150 GeV. If they are accelerated by 2hjo8 f12y gnb,gc*g3m .5 MV each revolution, how far do they travel and approximately how long does it take for them to reach 1.0 TeV? d$\approx $    $ \times 10^9\ \text{m}$

  (a) How much energy is released when an electron and a positron annihilamlr 2 qxg-ame.30i hnrat)2s0te each other? m2 qeag0 is a2nhl-rm)30.trx$E_{\text{total}}$=    MeV
(b) How much energy is released when a proton and an antiproton annihilate each other? (All particles have $KE = 0$.) $E_{\text{total}}$ =    MeV

Which of the following reactgcut-z--+isku )st6lkr 6 6upions are possible, and by what interaction could theys-k+s6u66 ug kzu l ci--trtp) occur? For those forbidden, explain why.
(a) $p + \pi^- \to K^+ + \Sigma^-$
(b) $p + \pi^+ \to K^+ + \Sigma^+$
(c) $p + \pi^- \to \Lambda^0 + K^0 + \pi^0$
(d) $p + \pi^+ \to \Sigma^0 + \pi^+$
(e) $p \to \pi^+ + e^- + \bar{\nu}_e$

Which of the following reactions are possible, and by what interaction coul1x82)r*v;jsm x gxwemt8hc ,md they occur? For thgj xmw vhx;8etcrs8x )12*m,mose forbidden, explain why.
(a) $p + \pi^- \to K^0 + p + \pi^0$
(b) $p + K^- \to \Lambda^0 + \pi^0$
(c) $n + K^+ \to \Sigma^+ + \pi^0 + \gamma$
(d) $K^- \to \pi^- + \pi^0 + \pi^+$
(e) $\pi^+ \to e^+ + \nu_e$

One decay mode for anub87,:kg jh ; anlg5 9 bwx-p/pwuzi/ $\pi^+$ is $\pi^+ \to \mu^+ + \nu_\mu$. What would be the equivalent decay for a $\pi^-$? Check conservation rules.

  Symmetry breaking occurs in the exg mpy pk7-73qlectroweak theory at about $10^{-18}\ \text{m}$. Show that this corresponds to an energy that is on the order of the mass of the W boson ($M_W c^2 \approx 80\ \text{GeV}$). $mc^2$$\approx$   GeV

  The mass of a $\pi^0$ can be measured by observing the reaction $\pi^- + p \to \pi^0 + n$ at very low incident $\pi^-$ kinetic energy (assume it is zero). The neutron is observed to be emitted with a kinetic energy of 0.60 MeV. Use conservation of energy and momentum to determine the $\pi^0$ mass. $E_{\pi^0}$ =    $MeV/c^2$

  Calculate the Q-value for each of the ako)b: w jtubwb p(+w 53gv6g6reactions, Eq. 32-4, for producing a pion. w(tka 56)gjgo wvwb p3bb+:6u $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-valu/itre2- 3ipoi e for the reaction $\pi^- + p \to \Lambda^0 + K^0$ when negative pions strike stationary protons. Estimate the minimum pion kinetic energy needed to produce this reaction. [Hint: Assume $\Lambda^0$ and $K^0$ move off with the same velocity.]
Q =    MeV
$\text{KE}_{\pi^-}$ =    MeV

  How many fundamental fermions are there in a wpiap,kdwwe;xc;-t/) :v1 qm w ater molecule?    fermions

  A proton and an antiproton annihilate each other at rest (ybo k6)g23gy/ dbk***esq ouix w*zxand produce two pions, * *)(dgwsb6 qz3 guyoio*kyx /bxe2*k$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called unificatio47c8px4wteia n distance of $10^{-31}\ \text{m}$ in grand unified theory is equivalent to an energy of about $10^{16}\ \text{GeV}$. Use the uncertainty principle, and also de Broglie's wavelength formula, and explain how they apply. $\Delta E$ =    $ \times 10^{16}$GeV E =    $ \times 10^{15}$
(b) Calculate the temperature corresponding to $10^{16}\ \text{GeV}$. E =    $10^{28} K$

For the reaction $p + p \to 3p + \bar{p}$, where one of the initial protons is at rest, use relativistic formulas to show that the threshold energy is $6m_p c^2$, equal to three times the magnitude of the Q-value of the reaction, where $m_p$ is the proton mass. [Hint: Assume all final particles have the same velocity.]

  The lifetimes listed in Table 32-2 are in terms of proper t xjktd:gw1e.0z;hq rcy u-p+,ime, measured in a reference frame where the particle is zq1x0dg :kp,he. -t j+;ru wycat rest. If a tau lepton is created with a kinetic energy of 450 MeV, how long would its track be as measured in the lab, on average, ignoring any collisions? $\Delta x_{\text{lab}} = $    $ \times 10^{-5}\ \text{m}$

Identify the missing particle in the following reactioowcg;; - k zu)+mc9/:9 d9mofbr6i y eiibmf8nns.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model toru)*9/hrf wr+oq mk k: describe the reaction $p + n \to \pi^+ + \pi^-$.

What fraction of theq,8 zilrz9 o67f7 t5lhoh(vd4x8wr bqii c7,b speed of light $c$ is the speed of a 7.0-TeV proton?