Give a reaction between two nucleons, similar to Eq. 32-4, that cw s bs-tg:y8,hould produce a :sh 8t-sg byw,$\pi^0$.

  If a proton is moving at verywh1ui9h / yrvlgj55i.nitd jb +061jt high speed, so that its kinetic energy is much greater than it+. 90l tjgt j5bhwhuv1yi/5nri d i6j1s rest energy ($mc^2$), can it then decay via $p \to n + \pi^+$?  ----待选择----yesno 

What would an "antiatom," made up of the antiparticles to the constit05p lgi* 2mienuents of normal atoms, consist of? What might happen if antimatter, mpien 50 m*2iglade of such antiatoms, came in contact with our normal world of matter?

What particle in a decay signals the electromagnetic interacti(t p tuz 2pd.o.zi5y0o a;be*don?

Does the presence of a neutrino among the decay products of a particle nebcig*t,sy76z c8bav r7d :a+;(cyqslcessarily mean th;*t 6azl( v+sc 7dsbyrbqc,y87c gai:at the 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 td4vht:sjc xgqwwh g p99h.gh9 p86g1:he weak interaction even though the neutron and one of its decay products (proton) are strongly interacting?qtg8wphs hh:pggx: w9 v19 d9j h.6g4c

Which of the four interactions (strong, electroma l wtkrfr.*syifqg +6he bc4kk(4g 05(gnetic, weak, gravitational) doesbkffk0*gq4srk wh 4.gi(t y +l(r56ec an electron take part in? A neutrino? A proton?

Check that charge and baryon number are conserved in each of the decay lt-ioyoupdc-wh x0f* s7m:: 5 yozdq7u92sy2s in Table u :wly:9os-c57yt dipx2h 027omyqzu -o sf*d32-2.

Which of the particle decbd/k s 3ki y+i*w:,p:h ysk;q)eh6gx zays in Table 32-2 occur via the electromagnetic interactib*zd,; w3y /kksi:qys xh)h+6:ei pgk on?

Which of the particle decays in Table 32-2 occu3-meefigx6 ) xr by the weak interaction?

By what interaction, anq3s f.*tn*fy0onkg v 5rn;e4t h-+aqid why, 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 Table 32-4 occur via theppltr.sy ak45/ p 3k7)zc nis; electromagnetic interactitpc nlk7; py35ak 4sir )./zpson?

Which of the particle decays in Table 32-4 occur by the weak interaction9zrq j n:j0jt(?

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" that was mas)o +spn)f c5 (yh60vy oypwzb0sless, had no color charge or electrical charge, and did not feel the weak force. Could you say that this particle o+)06z(y nybp 5w h s0vco)yfpeven exists?

  Is it possible for a particle to beqw1g gio gg/j+3sf;kaxr af7-r* , bl3 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 chromodynamics3ocaw3os 53yt , would it be possible to find particles made up of two quarks and no antiquarks? What about two quarks and ya5stcwo33 3otwo antiquarks?

Why do neutrons decay when they are free but not when they are inzy9dp*t8 vml8 side the nucleus?9 y*8dlzv 8mpt

  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(sgfb+z83 6r jftn u6y is 6.35 GeV?    GeV

  Calculate the wavelength of 35-GeV el i clelpe /,gf6(uh4umu aq(8sxlv700ectrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used liqpcyi/+ (0pv)c3qyc)qkn1in a cyclotron in which protons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one complete revolution r tb;wrfi2i.6for a very high-energy proton in the 1.0-km-radius Fermilab accelerator? T r6i f2.;riw tb=     $ \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 Exaz( 4 *3rwmmd1*96 y al gr+zfrlau)mcimple 32-2 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 pickiw 6aqqwtr9j +0ng out details of the nucleus: 30-MeV alpha particles or 30-MeV protons? Compare each of their wavelengths with the size a rq6 w9jqt+w0of a nucleon in a nucleus.  ----待选择---- alpha particles protons 

  The voltage across the bp qji,3y 2r4k14wshpa5ja9s) hfa v (dees of a cyclotron is 55 kV. How many revolutions do protons mbhy h2pav4,4i( wkp3s 91ja jq )5fsarake to reach a kinetic energy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelength ((huljl :a-o ,d:a fyr(3b* zzv$\lambda$, maximum resolvable distance) of 7.0-TeV protons? E =    $\times 10^{-19}\ \text{m}$

  A cyclotron with a radius ofs h-chvth93 3y 1.0 m is to accelerate 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 housj: /ar2sj7;f mpdf+m ne the magnets for the Large Hadron Collider (LHC) calls adm p/;7ns2fr:j+mfj for proton beams of energy 7.0 TeV. What magnetic field will be required? B =    T

  The 1.0-km radius Fermilab Tevatron takes about 20 secx5*sty ts iwq;d,7c(fonds to 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. (You can assume that the speed of the protoc,5fxy qti7*wd (s;stns is essentially $c$ the whole time.) Energy/revolution =    MeV/rev

Show that the energy of a particle (chari.fht.ip) 6s oge $e$) 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 needed at the 1.0-km-radius Fermilab synchrotrvy rrwrq1vw,+(bsi56on for 1.0-TeV protons? B ywi(qr 6,5b1r r+wvvs=    T

  How much energy is released in the decayd7)jd1jt+ xmke ./j2 e g7nzyw $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is released when a t(w3chz7vxvf9a;z8p $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is requi8)bpq d8cy vjve;oi5, red to produce a neutron-antineutron pair?    MeV

  Estimate the range of the strong fi 1, nymxfbw6z5gqnpqm; otie e9d)w -m/.3h 7orce if the mediating particle were the kaon insteadwi n,nmx1ib; f) -/7q6dyqe 5h9g. wop mezt3m of the pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equal speeds. What minimum kinetiywvw8kid b //*c energy must k8*b/d yv w/wieach have if a $\pi^0$ meson is to be created in the process? (See Table 32-2.)    MeV

  What minimum kinetic energy must two neutrons eaca:4tkbt(w3 oz9bu95sxx ptl- ea wug5h/3 1tuh have if they are traveling at the sampkt uu:zbs x otx45(t931l g-ha tuwb95w3a /ee speed 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. 32-3, given the masses of trz7/cjvfa mrzkpm+uu c9n4pxxt 36v1-6) n(k he W and Z parpuf 91nczm/ c4jv6amr r6xvu(kxz)7-n 3tkp+ticles 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 pror4mci(d4gy(zp ; l9eoduced when a proton and antiproton at rest anne l4 c9g4dzym(i rp(o;ihilate? $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 if*eti2wz*/g* rvq tv;solated electron to radiate only a single photon. (b) With this result in m t/fq v*ir*g2wvtz e*;ind, how can you defend the photon exchange diagram in (Fig. Below)?

  What would be the wavelengths of the two photons produced whee6 1/ dpolp)8k+ rk +vj*bbvvgn an electron and a positron, each with 420 keV of kinetivpkkb/)1 j+*oed g bl+ 8r6vvpc 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 d*pk :zf 37g m*kdb1kmpossible? For those forbidden, explain m7f k:*kzdgbkp3 *md1what 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 ener+hpb rkf:va 1*d.7y higy 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 energy of the q 2z/v q1l)/2et aftgu2xq) gbuyj:8delectron 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 thecae1/cqf: is2n/fa: l6 ie)+tlv2k sgn the lifetime of the $\Delta$ resonance using the uncertainty principle.
$\Delta E$ =    MeV
$\Delta t$=    $ \times 10^{-24}\ \text{s}$

  The measured width of the bg;o41b /v li qblp+v1$\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width of thev7koo sb( 0r+h 9k6dhn $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or uncertaintyn*d57x-6n lkgeyrf .y ) 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 fo *z9oziqei7474 dskokwj* kyn(dc97srbidden, explain which laws are violated. zw4ei kcdn 97(* o9sisd qjy4k7 k7oz*
(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 fonz6onta *+ 9y3.lb avtrm (a) a neutron, (b) an antineutron, (c) t t9+znnbo *6.yava3l a $\pi^+$, (d) a $K^-$?

What particles do the following quark c rb0-u94ppmewh l2 ob 6c1k-7uyw7tt tombinations produce: (a) $uud$, (b) $uu\bar{d}$, (c) $u\bar{s}$, (d) $\bar{d}u$, (e) $c\bar{s}$?

What is the quark co*o bg*dti/cq2+c oj8 pmbination needed 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 quarks (as in *mzs;to1g imeb 7fb9 pu*( o,sFig. Below) for the reaction g if b9,uze(;to1 m7s**b sopm$p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for the reactiwsin+x4xq2hdp: l;a : on $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of)bplcsy7p pn5gz;+ p0 a proton whose kinetic energy is 25 GeV? What is its wavelel+np)bp7 spz0c; gy5pngth?
$\approx$    $ \ \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 into the 1.0-km-gd+ l(r2hfbh+ l y/ws+9to6 sxradius Fermilab Tevatron with an energy of 150 GeV. If they are accelerated by 2.+lg9h2bhf 6dxot/ w+r y+ls(s5 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 electro rlv y(pk/enn s w9yrv.*.(erc1l3v *fn and a positron annihilate each orv*3s p/nn9 (c relf 1r. w*kvy.(leyvther? $E_{\text{total}}$=    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 reac0/b h*aon. nvstions are possible, and by what interaction could they occur?b0nva*. nho s/ 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 aa .v4pnpucgb - 66mne3* r:ctcre possible, and by what interaction could they occur? For those forbiddv6te6n. 4cp:pc3-rcm g*bnu aen, 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 aq8 htss fn(2 o5/vt;.y fwjwo: $\pi^+$ is $\pi^+ \to \mu^+ + \nu_\mu$. What would be the equivalent decay for a $\pi^-$? Check conservation rules.

  Symmetry breaking occurs in the electro:)-hrfqe9xnb- d o7qc)r /xojweak 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 zh(ng- e4583z nir/m +hsapnj for each of the reactions, Eq. 32-4, for producing a pion. nnei8z 5 amrnpj3gzh-hs +(/4 $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value for the re:o l+6nc;rhrl 9dga:;flye l;action $\pi^- + p \to \Lambda^0 + K^0$ 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 ar)k (eqh-y+s 9 4efruoxe there in a water molecule?    fermions

  A proton and an antiproton annihilate evd gv 20ew0wwe ,7qd08wwi)isz- 6jnyach other at rest and produce two pions, dwwv8s2-v d0q0wge ,z w7)6yj wii en0$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called unificat k8h4dxa jaz89ion 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 timeys3 v8vmu+ rnz4,(*xpu(hshc, measured in a reference frame where the particle is ah sn, h+ usm8x(v3z cvr*yup4(t 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 reactiyl,:fh+d l yq+ hu( 8*00mmi8in gwvynons.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to describe the reaction cpukv9g*k ,9 s;d4(lf r9 gkih$p + n \to \pi^+ + \pi^-$.

What fraction of the speed of 7jnpsg5si)6ad lvm(:+dn d (alight $c$ is the speed of a 7.0-TeV proton?