Give a reaction between two nucleons, similar to Eq. 32-4, that could produce lk mlxh( :rur*lk7a-8a 7k8 ka lu hx-m(*r:lrl$\pi^0$.

  If a proton is moving atb sbehqkxn 8e 6m*c4w0052yqn very high speed, so that its kinetic energy is much grea0qwebh eb nxy*m0 ks6c 824q5nter 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 of the antiparti:j1ex6tgj+, fj05anfwinf*lcles to the constituents of normal atoms, consist of? What might happen if antimatter, made of such antiatoms, came in contact with ourt1jg0fef:ljfj * ixnw+na5,6 normal world of matter?

What particle in a decay signxpq wc50gr(*o7 b,x f,lau /inals the electromagnetic interaction?

Does the presence of a neutricxvm zpt;7;;cmx1a /u no among the decay products of a particle necessarily mean that the decay occurs via the weak interaction? Do all decays via the weak interaction produce x;v cp;x7/t;macm1z ua neutrino? Explain.

Why is it that a neutron decays via the weak interaction even vbkq, xqg+1 hlcr:z;i co706hthough the neutron and one of its decay producth1;xz7+c0b i:6qhvcor l ,qkgs (proton) are strongly interacting?

Which of the four interactions (jeanj6n** wn5 jqg6nkhe0 0i1 strong, electromagnetic, weak, gravitational) does an electroi6hj6w0g 51 n* jn0jen *qnekan take part in? A neutrino? A proton?

Check that charge and baryon number are conserved in each of the dev stus9 sl i8iy 2k*cfyn/(4b8cays in Table 3u/ 9s8c 4 biys2stflv*(8iy nk2-2.

Which of the particle decays in Table 32-2 occur via 5 +/xlmx 3q+s7ejd kefthe electromagnetic interaction?+je3x5ef m7+ k dqsxl/

Which of the particle decays in Table 32-2 occur by the weak intera( r+ crwvwny.k0y/i :rction?

By what interaction,mu. / phmphn.:k5 ouvx (mbr*26ife+ b 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 des bd*i68swawhm1,kk *+ugf5 acays in Table 32-4 occur via the electromagnetic interaction?wai+6,k1 ms5a*fsbugk wd8 * h

Which of the particle decays in Table 32-4 occur by wy+flscw2**kvjx:cq *je qk -8wm )3othe 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" th.j8 q, wjg/tuqat was massless, had no color charge or electrical charge, and did not feel the weak force. Could you say that this particle even exi jw8q,q.jg/t usts?

  Is it possible for a part/q5i s;k5zbqaicle 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, would it be poso n19h n9b15 v,ivmwadzfl -/wsible to find particles made up of two quarks and no antiquarks? What about two qzvi n/ ,fad15v 9h1ml wown9b-uarks and two antiquarks?

Why do neutrons decay when they are free but not when thee9uhbz9;ixz n;5p ou5z8pmi 2fk0pl6y are inside the nucleuexkz2uzop b50p ;8m96ni uz;h9if5pls?

  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 enjdl *s-.,jhlckv- t :gergy is 6.35 GeV?    GeV

  Calculate the waveleng5y3(a *dhqh;fg qkb 7y1i2lgq ,d g49x7wdqjwth of 35-GeV electrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in b0r4s ub2 t8npfj19h pa cyclotron in which protons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one complete revolution for a very high-energy proto xzfj .6m(jn8ug: hrk0n in the 1.0-km-rn umr(j zk0hg8f:6j .xadius 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 cyclotronb4kb21 .jiae1h; qdic of Example 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 picking out details of the nucleus: 30-MeV alphlfmn5 r+f; b ;:5ep0y aon*vj w (r/p8otct7bga particles or 30-MeV protons? Compare fby /v8w n7r ato* ;lr f;(tomgcb5n:e0 p5j+peach of their wavelengths 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 revolj,zi*vry;s v:ze :1y yutions do protons make to rey:v zziv je ,*;ys1y:rach a kinetic energy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelength0acb/:a(k o/cqn/ pai2flc3 m ($\lambda$, 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 accelerate ynie(wn/fcfg5 grq,h6g:q - 8 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 us el9df91 u4yesed to house the magnets for the Large Hadron Collider (LHC) calls for proton beams of energy 7.0 TeV. What magnetic field will be req9 4udl1ese fy9uired? B =    T

  The 1.0-km radius Fermilab Tevatr6- n) np:intb mp6cyn8on takes about 20 seconds to bring the energies of the stored protons from 150 Gn8mn6- nicy ppb:6nt)eV 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 protons is essentially $c$ the whole time.) Energy/revolution =    MeV/rev

Show that the energy of a particle (charge x9fr1li+iv3x$e$) 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-radi :dg6 )usr7fooifed45usl ;o,*wziv5us Fermilab synchrotro:4r iwouf,6di fzes*o; 75dsgul )v o5n for 1.0-TeV protons? B =    T

  How much energy is released in a5- /yq s ncy,,)irw,+zxmdgpthe decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy +k 8t(grh6 5j7dojjvkis released when a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is required to produce a neutron-antineutron pairo 40igb0s;z *loiswg-?    MeV

  Estimate the range of the strong force in4t;uw 4iun 9+l,yn fzf the mediating particle were the kaon instninu4;l4u yt+9znw,fead of the pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equal speed: j ji/- zgdeyi5(ot,as. What minimum kinetic energy must egi/-iay:5ej(djt,z oach 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 nb u::6* wll/ps g9kxjeach have if they are traveling at the same speed toward each other, collide, and produxs g:ubjl/l*:k9 nw6pce a $\pi^0$ pair in addition to themselves? (See Table 32-2.)    MeV

  Estimate the range of the weak force using Eq. 32-3, give4 +i*lb.oo,suri 6wytn the masses of the W and Z particles as abouy.lru,io*i46obsw t+t 80 to $90\ \text{GeV}/c^2$. $mc^2$$\approx $    $\times 10^{-18}\ \text{m}$

  What are the wavelengths ofe lalc-6 qqjyd78 iq,pw;b2v . the two photons produced when a proton and antiproton at rest a.l8ajv 2pqe-7c , yqd6wbi;l qnnihilate? $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 e 2.zra 95,syllycyp*(asg7 tdnergy, that it is impossible for an isolated electr.y l *75pls tys(zyrd9g2a,acon 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 the two pl)hd.+ qllt 0* vz+dkbhotons produced when an electron and a positron, each with 420 keV of kinetic energy, anni0*zlt.h+ldk)qv ld b+ hilate 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 tna f9a 6 jtin9zc8,*rwhose forbidden, explain what laws zfn ,r6cj*tiana98w9are 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 thea4bokur9e 1 n*,9eelp 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 tye: ff.ka*tyogu6. i2c7f5athe 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 lifetim dgu n,v11 j ae) o53twdar)ei(ax.jrb89wu*ge of the $\Delta$ resonance using the uncertainty principle.
$\Delta E$ =    MeV
$\Delta t$=    $ \times 10^{-24}\ \text{s}$

  The measured width ofsa *.ixpirk+3 s5q.;2 fznufp the $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width ofa tg4 bb1:: hoek,y7ajychx84 the $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or uncertainty) gyw3j3pa5ag,o v;w . yof
(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 amfc spz ; t4lg(x;ilphloo:+ 40m,zg:re forbidden, explain which laws are violated. :,h(l:tmcixp+4 l lzf g ;zogo;m04 ps
(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 foi9b*og9orqwbpof8 3 *rm (a) a neutron, (b) an antineutron, (c) abo i*w p q39fb9gro*o8 $\pi^+$, (d) a $K^-$?

What particles do the following quark c78(zoayek i:0 :eb6yngwp2b u* ulk7hombinations 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 producdg: tu6,s tbfd r0nb;d9a 7ku4e 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 usiyrtv/p i 8p7l1ng quarks (as in Fig. Below) for the reaction r 1i /lpvyp87t$p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for the reaction+;w ; )lwlh )b9hgckon $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a pro nq t -u/ (3tjmh k7kt30y(ndp1v1camdton whose kinetic energy is 25 GeV? What is its wavelength? kyhtt11-mnn(vt7/q u3ajkc3 m (ddp0
$\approx$    $ \ \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-radius Febnytfl* 3(qa (:wd:d7bvi ;turmilab Tevatron with an energy of 150 GeV. If they are accelerated by 2.5 MV each ra(:di;3utbqnbdwt7y lf v* :(evolution, 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 annihxps-5 *beukn;g+8kte ilate each othen* ;eep5tgbxk -8ku +sr? $E_{\text{total}}$=    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 possibles yb1;e6ucin*l*2(t xgug z9 o, and by what interaction could they occur? For those forbidden, ol e; g y*i2xtgcsu*9buz(6 1nexplain 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 intc gcwv0 b9.(,n g4mjr oj,*ibleraction could they*40 bngl(,c,bom. j gw9vrcji occur? For those 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 apy z7idfvfyq * 131vv* $\pi^+$ is $\pi^+ \to \mu^+ + \nu_\mu$. What would be the equivalent decay for a $\pi^-$? Check conservation rules.

  Symmetry breaking occurs in the electroweak theory at aboutn/(-h+xgp eh8r5e:i wxn+ a zp $10^{-18}\ \text{m}$. 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*8laaf5j ig:qu s2b+h each of the reactions, Eq. 32-4, for producing a pion. *85la:gb hju+ fi2aqs $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value for the rn-5suw iq8jp:eaction $\pi^- + p \to \Lambda^0 + K^0$ 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 fundamentalq o(r oc8d ed;yvl3no3b9 1,lh fermions are there in a water molecule?    fermions

  A proton and an antiproton annihilapal4n.m4bhl 8 te each other at rest and produce two pions, nabl hp m48.l4$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so9b5mqsznu)pq -x s)3b -called unification 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 time, measu; ea pfxp1f0q,red in a reference frame where the particle is at rest. If a tau lepton is created withq;xf eapf ,10p 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 re -02xj5pz 8dv hnq2pfzt 7pl/eactions.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to describe the 3hx (9lzmuu) d:m+mi freaction $p + n \to \pi^+ + \pi^-$.

What fraction of the speed of vxuoe29f n,vuv*(p1 y light $c$ is the speed of a 7.0-TeV proton?