Give a reaction between two nucleons, sil9 xq4ne.:obo p )kl7hmilar to Eq. 32-4, that could produce a pq nx 7o)l.lbk:9he 4o$\pi^0$.

  If a proton is moving at very high speed, so that uo+z5 i0qhf0*ys2uxtbl i *z9its kinetic energy is much greater than its rest energy yit zqx+l02hb0*i9 uf5zuos* ($mc^2$), can it then decay via $p \to n + \pi^+$?  ----待选择----yesno 

What would an "antiatom," mi 3ww6,i dv b9,anq9 cphetk paca6r0m5. z6g/ade up of the antiparticles to the constituents of normal atoms, consist ofh a ew6gi b t ca/m,06.izdp qark3,c9w569npv? 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 electrom) *rav(q4vms - ejooo2agnetic interaction?

Does the presence of a neutrino among tm6dj*u0r:oj y 48 ptixhe decay products of a particle necessarily mean that the decay occurs via the weak interaction? Do all decays via the weak interactiyjptm6*uo 0dxj 48r:ion produce a neutrino? Explain.

Why is it that a neutron decays via the weak inter:gsp; )brg9yw action even though the neutron and one of its g9by):s; pwrg decay products (proton) are strongly interacting?

Which of the four interactions se cu(i/dlp03 (strong, electromagnetic, weak, gravitational) does an electron take part inu/s( ildce30 p? A neutrino? A proton?

Check that charge and baryon number are conserptduzsf;x( * l/0ah uj.e x5c,ved in each of the decays in Table 32u la ;jp/*h,0ztexc.u5sf xd (-2.

Which of the particle decays in Table 32-2 occur via the electroma( .r dkcc mu9b0,xvaz(gnetic interaction?k mba .r0 (vc9dc(xz,u

Which of the particle decays in Table 32-2 occur by the weak interaction?wveod0b) lr8syj: (9vmw0. r e

By what interaction, and why, does d6(xq0 ki6aqz $\Sigma^0$ 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 qre vlk8 e9:3lz. 36yg+ hfpccin Table 32-4 occur via the electromagnetic interactv:cr zg.lyl9e e+ f8pk36hc3qion?

Which of the particle decaebxst++8 8gqx ys in Table 32-4 occur 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" that was mass5cu y2zg u)aanb3pn :0less, had no color charge or electrical charge, and did not feel the waba u2zn3p:ng) 5 yu0ceak force. Could you say that this particle even exists?

  Is it possible for a parti+o/84 0vqdpn/t0 qrf veibh,scle 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 chromo*gj wovr6j, ztu)w7u 5dynamics, would it be possible to find particles made up 7jv* wru6u,5oztw)g jof two quarks and no antiquarks? What about two quarks and two antiquarks?

Why do neutrons decay when thmlz1((8 vz72rpd q :ev4xxm giey are free but not when they are inside the nucleus?x(i8(pmzqzrevm1 4v7d g2:l x

  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 en * w /yi5qtdpv, vk4izus o5k:/cva,w6ergy is 6.35 GeV?    GeV

  Calculate the wavelength of 35-Ge nrg-fyt;m3/qh w m05lV electrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field z-/iy.bh;zphjl-d ; x is used in a cyclotron in which protons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one (rv/cu( gx w;sbs i1x*complete revolution for a very high-energy proton in the 1.0-km-radius Fermilab accelerator?*xgwv ( i/ crub;1(sxs 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 accelerat ku,pj91yf0 m5zd8u8y ynel)fed $\alpha$ 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 pich r*d iq(u,n/oking out details of the nucleus: 30-MeV alpha particles or 30-MeV protons? Compare each of their wavelengths with the size of a nucleon in a nucle*i hu,r( dqn/ous.  ----待选择---- alpha particles protons 

  The voltage across the dees of a cyclotron is 55 kV. How many revoy,ay0;,b q6xzdvn yk(ul z7l *lutions do protons make to reach a kinetic energy of yz6v,dlu nx*b (07lyazy, ;k q25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelength+7xn/0vsm, opp6v ndy ($\lambda$, 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 n,f bu:wmbbr p*z)v+m:(xe w. 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 wlo4/ bkh4m8dg ill be used to house the magnets for the Large Hadron Collider (LHC) calls for proton beams of energy 7om bk/ g84ld4h.0 TeV. What magnetic field will be required? B =    T

  The 1.0-km radius Fermilab Tevatron takes about 2fa6h2 vpnz(xr np -p*;c iqk*40 seconds to bring the energies of the stored protons from 150 GeV to 1.0 TeV. The acceleration is done once nx q*(zpk;av*2-p h6rpcnf4i 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 (ch42lb))y ,:t9adyb bmvi4oezn*sis x9arge $e$) 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 syn7f ep09ybx4yk chrotron for 1.0-TeV protons0y7kp xbyfe4 9? B =    T

  How much energy is releasw1 ,h9uis.wz4flu/ h med in the decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is releasenha*k3 b52k eod when a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is required to produce a1uw8 wzbr2u h4 neutron-antineutron pair?    MeV

  Estimate the range of the strong force if the mediating particle we/a9a*mayn1y/fo -uasr 4+4in wt p5 pkre the kaon insteaypt a-*pri4nkmo/au 1 9f/ aaw54ny+sd of the pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with ep9*4 z5orum(9n mr )pa xp7zkuqual speeds. What minimum kinetic energy must uza*pn)m5p4 xm( u kz97r rpo9each 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 each have :w ,w8k30atkq dqjbzbv+4mw -if they are traveling at the same speed toward each other, collide, and produce ab av,qqwtz w4jmw:bd0 + 8k-3k $\pi^0$ pair in addition to themselves? (See Table 32-2.)    MeV

  Estimate the range of the weak force using Eq. 32-3, bk vlmc/3 8 :s4ec,bdrgiven the masses of the W and Z pa ,bk4cvlbem r: c/s3d8rticles 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 proton and anb6ln5xow1x3c vpm.s1 tiproton at rlw1obvp n3x.51c 6mxsest 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 ity44)7rpe gof8 *hcz2j8g a zwv is impossible for an isolated electron to radiate only a single photon. (b) With this result in mind, how can you defend the photon exchange diagram ino8cfzg8ezh2jyg 47 )r*4apwv (Fig. Below)?

  What would be the wavelengths of the two photons produced when a vjok:wii5 ed9cn-4i9o n -qp4brj+:qn electron and a positron, each with 420 keV of kinetic energy, anni:j+5qn qwbc-r9oin 4 jk-d 4 iie:po9vhilate 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 pz;c lwjg.z. bhl*i81g ossible? For those forbidden, explain what laws are violwb gg.jzz8 h1*;l icl.ated.
(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 -g4vj*el3rl pg2y uj6the 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 maximuoh457 ) vwg gf*5etl,tvbbu0 qm kinetic 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 estijby:;sreavr7t 4jsa o12h-s qw-8 k/j mate the energy width 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 os:8c ( .qom5f:tuedh the $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width of the mj08a bn+ *0p:iseq,ok,daod$J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or uncertainty) offvi9y);9xg-j1qi v k x
(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 thafe9p, ,+iekept are forbidden, explain which laws are violated. k epee,,+ fp9i
(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 . 5 wux:)wmvubneutron, (b) an antineutron, (c).) :vx5mb uwwu a $\pi^+$, (d) a $K^-$?

What particles do the following quark com3c o9x *zr5zevbinations produce: (a) $uud$, (b) $uu\bar{d}$, (c) $u\bar{s}$, (d) $\bar{d}u$, (e) $c\bar{s}$?

What is the quark combination n 2 ee,d2:m9x3k dirgkc9 adr)beeded 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 quareo bjk.*m0: rg1h 1ekiks (as in Fig. Below) for the reaction g: b.kj*k11eioh0 rem$p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for the reactionbzpxg.m0jul. ;3xa a8 $n + \nu_\mu \to p + \mu^-$.

  What is the total energkfq,zn,.jm( by of a proton whose kinetic energy is 25 GeV? What is its wavel, qjf (z.knm,bength?
$\approx$    $ \ \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 cc hmgrum-;/nh,e -2n 1.0-km-radius Fermilab Tevatron with an energy of 150 GeV. If they are accelerated by 2.5 MV each revolution, how fcn-gh-2m ,/hr muec; nar 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(n3 ymb duhp.6 when an electron and a positron annihilate each other? up.dyh6bmn 3($E_{\text{total}}$=    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 arw n. vj/ k34jhwo2cd5je possible, and by what interaction could they occur? For those.wdcjk /3h2jo4vwn5 j 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 whatohplrekj/trg d1:vx, c/ ;zbq 2-z:y 6 interaction could they occur? For those forbidden, explain d, r/ zkp-qz/tebgh:clj216o:;xvy rwhy.
(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 bdxbfxqenaq7; s/,2($\pi^+$ is $\pi^+ \to \mu^+ + \nu_\mu$. What would be the equivalent decay for a $\pi^-$? Check conservation rules.

  Symmetry breaking occurs in the electrowe j1:c9qfz*4fg.b6tejx uk 8drak 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 reactions, Eq. 32-4, for producinh8p0/s8zi4 d8w svvu ig a pion. 8ivu40 8dipws/h8zs v $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value f-txf; vl5mk9 ,)exkqyk5oyc- or 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 alaoq( gpj* jiqh.9 65l water molecule?    fermions

  A proton and an antiproton annihilate each other at )p8y3oz: h b 0d-klpejrest and produce two pions, 0o:8 )-y p3ld pjzbehk$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called unification distance ovpd00 b916w3nbey ip wdv3e,n1v py0(qz kl( bf $10^{-31}\ \text{m}$ 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 ofa rjq1s+uzh- g(r-bn(x t+w 7u proper time, 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, ignorinas+t1ngj (xruq-7h bw- uz(r+ g any collisions? $\Delta x_{\text{lab}} = $    $ \times 10^{-5}\ \text{m}$

Identify the missing particle in the following r0*dxhzdh nif46k b2urq8 n+ 5deactions.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to deuc*w 7 +somljnef, (c7/yg8f rscribe the reaction $p + n \to \pi^+ + \pi^-$.

What fraction of the spee0x5hn u)n g7bnd of light $c$ is the speed of a 7.0-TeV proton?