Give a reaction betwy; 3 , ,(f-mb q5vyq+dkithogc/w e*rgeen two nucleons, similar to Eq. 32-4, that could produce a yg;i gdwmvy o(kt+,f * hqr-e,c53 bq/$\pi^0$.

  If a proton is moving at very high speed, so that its kinetic energy 8pg(h68zd u5vau0 ejnia;e- eis much greatn 5aua8;i(8uz60hgdjvp eee-er than its rest energy ($mc^2$), can it then decay via $p \to n + \pi^+$?  ----待选择----yesno 

What would an "antiatom," made up ge/,)g-sj81l iw wy3 :jfknieof the antiparticles to the constituents of normal atg ikne )iljw:e/-8gj1 sy 3fw,oms, consist of? What might happen if antimatter, made of such antiatoms, came in contact with our normal world of matter?

What particle in a decay signals the electromagnetic interaction?pr( r6 3 .agqnhie8hp8

Does the presence of a neutrino among the decay pr6co ku0bn-v3qp)mb x60nad +qoducts of a particle necessarily mean that the decay occurs via the weak interaction? Do all decays via t-uk x6c a0b60v)n+q d nmopb3qhe weak interaction produce a neutrino? Explain.

Why is it that a neutron decaysh+r)ji9;- he+gywq wy via the weak interaction even though the neutron an; hygw+j9 yriw e)+-hqd one of its decay products (proton) are strongly interacting?

Which of the four interactions (strong, electromagnetic, weak, gravm6 .zsg v,es5vitational) does an electron take part in? A neutrino.vz5g6 svmes ,? A proton?

Check that charge and baryon number are conserved i kip1.6/t h spbi9)nzen each of the decays in Table 3kz6ei / ps1nhb. 9pti)2-2.

Which of the particle decays in T3f hb9*4 mpsr5 liqt9cable 32-2 occur via the electromagnetic interactb954*rq3sl ti9m hfcpion?

Which of the particle decays in Table 32-2 occur by the w/etoue5z9./(fy ahjt-ep 3sa eak interaction?

By what interaction, l8w+u/f xx5sb and 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 the electromagnetic inte +q5lts zgm o*zzy:cz,83y- qvraction?mlcy,*:ytz+58 3zvz-zq qo sg

Which of the particle decays in Table 32-4 occur4zgdq .,juf3deym 37ta-.l yb by the weak interaction?

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" tha*r2- z;qtu k/s* ccrrxl6fw) 4lxxu,u t was massless, had no color charge or electrical charge, and did not feel the weak force. Cutxk,r6qsf4ul/ x-; ul c2zcr *)x wr*ould you say that this particle even exists?

  Is it possible for a particlez:xkzkfbae2b mq7 w7 / 13k(kt to be 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, zv .ev6gwwg+w4v4s+r would it be possible to find particles made up of two quarks and no antiquarks? What about two quarks and two antiqgrz+ws+ v4v 6.w ev4wguarks?

Why do neutrons decay when they are free but not when they are ins8(re-76cpp(wgzkslq) bl ln2 ide the nucleus?nrw-(8 z2e p67gqlpl)bk(csl

  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 protonoe 5g i +4aijmapk*i;1 whose kinetic energy is 6.35 GeV?    GeV

  Calculate the wavelenkeo,3vpu abz xmo)7ckxgt/- 4f/86vzgth of 35-GeV electrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cyclotron icm 5-a9y;bu; 2wnwd rvn which protons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one c-+r;,o bejm6xbb (wp.r po1ia omplete revolution for a very high-energy proton in the 1.0-km-radius Fermilab accelerbjwi +,.6bbmpa;r -o p o1erx(ator? 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 32-2 8fk)bjj pxv.o2d 2(-2f dehlsaccelerated $\alpha$ 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 ) :8m2vw(rkzra)nzz4v: onl e details of the nucleus: 30-MeV alpha particles or 30-MeV protons? Compare each of their w)na zrok zwv:m4v:r2 e (8n)zlavelengths with the size of a nucleon in a nucleus.  ----待选择---- alpha particles protons 

  The voltage across the dees of a cyclotron is 55 kV. How many ren:/qt 2l+-voc oqmu3bvolutions do protons make to reach a kinetic energy of 25 MeV? c q/n2 :mo u+lov3qtb- $\approx $    $\ \text{revolutions}$

  What is the wavelengt (xawolw:i6q xk, lr/;h ($\lambda$, maximum resolvable distance) of 7.0-TeV protons? E =    $\times 10^{-19}\ \text{m}$

  A cyclotron with a raza0n qv,e a:b 1n2ry6*xek o *xmw4c)wdius of 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 house the magnets for the Lar:xd 96tx.n5y7bomta uge Hadron Collider (LHC) calls for proton bea:xbtm6.td5 o nua9 7yxms of energy 7.0 TeV. What magnetic field will be required? B =    T

  The 1.0-km radius Fermilab jr,f4,dg dxt,ls3 e :hTevatron takes about 20 seconds to bring the energies of the stored protons from 150 GeV to 1.0 TeV. The acceleration is don34,ferj,t x l:sd ,dghe once per turn. Estimate the energy given to the protons on each turn. (You 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 (q)lvf+p;lz9q-i y ev (j9j za2charge $e$) 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 ned1fkhruj*e),(d(0y yl/ mfe e eded at the 1.0-km-radius Fermilab synchrotron for 1.0-ukdld) fmf1y( (ej0yh, e*er/TeV protons? B =    T

  How much energy is releafs (amore(/9ic 63b7hrvm a(x sed in the decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is rei-)o9pm04 m +zpgj -veror-k0k7tmj eleased when a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is required2jz.lxwv 99pz tve ,qf+yi 96w to produce a neutron-antineutron pair?    MeV

  Estimate the range of the strong force if the mediating plg-maif c :d/.article were the kaon inste.cigd/m fa :-lad of the pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equal speeds. What minimldq: b7c9q;k bum kinetic energy must eacqc;bl k7:qb9dh have if a $\pi^0$ meson is to be created in the process? (See Table 32-2.)    MeV

  What minimum kinetic energy mustg/ r 484 pphbm-1glqy5p8vjji two neutrons each have if they are traveling at the same speed towapgjlbp4q1h8vr p8 j/5i- ym 4grd 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 usv xq4w.3ow d)*scns3fing Eq. 32-3, given the masses of the W and Z partic wf.ws4 v 33q*csnoxd)les 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 pzyf qt5b 3*ra6f1mf/ broduced when a proton and antiproto yr/*f5b6a 13 qmtfzfbn at rest annihilate? $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 imposs1xh6ikw ;wui4ngvm *j.k3 7 vlible for an isolated elewu*khx3 g ;4ivi67lwm 1j.n kvctron to radiate only a single photon. (b) With this result in mind, how can you defend the photon exchange diagram in (Fig. Below)?

  What would be the wavelengths of pki8b4 oj1/euthe two photons produced when an electron and a positron, each with 420 keV of kini/oju bk8pe41etic 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 followinp2w9 gn,r ajl,g reactions and decays are possible? For those forbidden, explain what lawrn pg,w ,la92js 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 energy of each of the two products in the decay ;jzweq+ +9 mfx$\Xi^- \to \Lambda^0 + \pi^-$. 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 ki3;l gj6bdm (+*ytm5/gudnpge netic energy 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 wh5 qv1l 3m*sfwidth and then 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 1zc)qn h+(crlfzhqg );9o mj0 $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width of thez*d0 9rv m ; s(n.pce+qni.dyq $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or uncertai ard /,b-b.ymgnty) 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 a7xf fqgi f-0s*re possible? For those that are forbidden, explain which laws are vi xsfgf *7-0iqfolated.
(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 neutron, (b) an antin7 ia0f w+pgi v 8srl0e(w+)tsteutron, (cp r00++it lfs(8vae w)gitw7s) a $\pi^+$, (d) a $K^-$?

What particles do the following 3+f6y jedpbbe6rp b 5*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 needed to produce a ) ),ct)u*gme( yxyua18ktbmqh:dne/ $D^+$ 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 q,-wsk0 d+d2gcr9z wy diagram using quarks (as in Fig. Below) for the reactionkw q 2sd+r0zc,gyw 9-d $p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for the rkb7 d+6/c n70h /-a wlqfhzrgdeaction $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a proton whol(j,:e.7m yfm xctfj3se kinetic energy is 25 GeV? What is its wavelengthmy( t3.e7m cxjf:,lf j?
$\approx$    $ \ \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-radz6bs-h7 wg *vvd:cmf0ius Fermilab Tevatron with an energy of 150 GeV. If they are accelerated by 2.5 MV each revolution, how far do they travel and approximately how long does it take for them to reach 1.0 6hbvsf07v:-*zcg dm wTeV? d$\approx $    $ \times 10^9\ \text{m}$

  (a) How much energy is released when an electron and a positron annihilate m,uo.d pai( m6;juwm6each otho, i6m;j mp6.wmda u(uer? $E_{\text{total}}$=    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 reactions are possible, and by what interaction could w soerxjo vcfg36,25rv9:; om they occur? For those forbidden, explain why. :jv;c, oo9m5r36o rvgwxf2e s
(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, p.afem,zbcf*v8j)9 h) 0av dog1 ej,iand by what interaction could they occur? For those forbidden, explain we)0,f.9v epjz8a d f vi1*mj a,o)hcbghy.
(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 a 9 o ,8wuzzzv iu//.hgp$\pi^+$ is $\pi^+ \to \mu^+ + \nu_\mu$. What would be the equivalent decay for a $\pi^-$? Check conservation rules.

  Symmetry breaking occurs in the electroweak theorya8d4hirdnre.j.0 6 to .bnky- 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 reactions, Eq. 32-4, for prglf +t1i 3um usf)o85ycf9p*zoducing a pion. f8fipou )g *1fs5 +9ylcm z3tu $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value bpl( 4c3ku )rrfor 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 water moleculwl /c (nab0zj fyy (4t0ed)gs:e?    fermions

  A proton and an antiproton annihilate each other at rest and produce two pions9q*cjmg,mkpo qyj . )/1g frv4, jgv4rym /91,fk p*qcm gjqo.)$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called unification distance ofn)f:uyy/o + in $10^{-31}\ \text{m}$ 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 iz:k qx(l.q:1) 3; fiih btmeqtime, measured in a reference frame where the particle is at 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?ixi ;l1:)zf:q(q beitq.khm 3 $\Delta x_{\text{lab}} = $    $ \times 10^{-5}\ \text{m}$

Identify the missing po. ai w;4mevh 55a5onjarticle in the following reactions.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model tocgtu jz0oi,m vg4o91 g1+5 afo describe the reaction $p + n \to \pi^+ + \pi^-$.

What fraction of the speed of l +e)sm*fw uf bo3l3 ygk:s2w*xight $c$ is the speed of a 7.0-TeV proton?