Give a reaction between two nun4psi -4w9yj;waqwuaj tg f65* o9v i*cleons, similar to Eq. 32-4, that could produce a nqyj6vi4 u5pjow9s-a9awg *i;4wf * t$\pi^0$.

  If a proton is moving at very high sp7orca.b6mj 5 meed, so that its kinetic energy is much greater than it7j5 .oc ram6mbs rest energy ($mc^2$), can it then decay via $p \to n + \pi^+$?  ----待选择----yesno 

What would an "antiatom," made unwq6k*9k qrhu c 0q-h0p of the antiparticles to the constituents of norm0r*qu kn-qh w c90qh6kal atoms, 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 electromagnetikwrk mzfj w;w */y5r)d3f3j 8tc interaction?

Does the presence of a neutb1p+e gj) 7xobykak30rino among the decay products of a particle necessarily mean that the decay occurs via the weak inte0kg)yxb7ke1+ j b3oparaction? Do all decays via the weak interaction produce a neutrino? Explain.

Why is it that a neutron decays via the weak interaction even though thu+ha*urmlv 9.3i 8 wczja,2iae neutron and one of i iazwma3i2 8h*c,ulr9u +.jav ts decay products (proton) are strongly interacting?

Which of the four interactions (strong, electromagne zo0+5ng ghqlpg:dq *6tic, weak, gravitational) does an electron take part ig*g :hg+0pq olzdq56n n? A neutrino? A proton?

Check that charge and baryone8jd( sw14 bkq3v 1 l4qgjh,lj number are conserved in each of the decays in Table qjwk,es( 4jv8j 1d3hgll14 bq 32-2.

Which of the particle decays in Table 32-2 occur via the electromagnetic interacl2x,d/rzxx8 ltion?8x/l ,xl2xzd r

Which of the particle decays in Table 3j9q 4ptw88zj -j8 t+jacacakk(hd 9;w2-2 occur by the weak interaction?

By what interaction, and why, doe vhjg :neb-l6: 0qd*sos $\Sigma^0$ 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 Tabw4se/ vuf27 fcoipp +ew;h1s) le 32-4 occur via the electromagnetic interacp) s;we ou4w hf 7ce2sf1+vpi/tion?

Which of the particle de rp7 pl+4tg1bqcays 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 massless, had no color chahiqr(ip8)2 q xrge or electrical charge, and did not feel the weak force. Could you say thaqpqirx) 2( ih8t this particle even exists?

  Is it possible for a particl,e w85:nw9br )a6j2i5eto-dq pk gdnm e 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 p / zjtk:st40b envqb8in5.( ,ab5 qagvossible to find particles made up of two quarks and no antiquarks? What about two q v k,st:bginejbzq0 a(.8/a5vbn 5q4tuarks and two antiquarks?

Why do neutrons decay wh2,z e1gs;(dz gt5cfz xen they are free but not when they are inside the nucleusf2zd z(e5 s1txg ;,zgc?

  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 6.3pm.);.o) xay,swyqn f 5 GeV?    GeV

  Calculate the wavelength of 35-GeV elect)rff /n-1 )y 4anjfbqzrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cyclotron in which pros (sj 15ejwv;orbce5/f0 : mkdtons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one complete revolution for a very high-energy proko:if/z/hx)7f6 gp h pton in the 1.0-km-radius Fermilab accefkp) g/ofi7 p:zx6/hh lerator? 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-; o (t-xdzuxu 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 alpha particles oo( 05hqhks: webms0: br 30-MeV protons? Compare each of their wavelengths with the size of a nucleon in a nucl0wo0 bh emh5 s:(sbq:keus.  ----待选择---- alpha particles protons 

  The voltage across the dees of a cyclotron is 55 kV. How many vufr2 /x43nowrevolutions do protons make to reau/ vwxr3 4fo2nch a kinetic energy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelengt(c vaafr5ng, 5wab- 0eh ($\lambda$, maximum resolvable distance) of 7.0-TeV protons? E =    $\times 10^{-19}\ \text{m}$

  A cyclotron with a radius of 1.0 l,9rwa n,,1z vbkq5 nix)ml2cm 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 tk uer*ned3 -26xkqb87g n.ywwe x; t)magnets for the Large Hadron Cxq ruebndwe t*3 ;7k t y-)wkx.n2ge68ollider (LHC) calls for proton beams of energy 7.0 TeV. What magnetic field will be required? B =    T

  The 1.0-km radius Fermilab Tevatron takes aboutu: ;i4ijof-fy 20 seconds 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 c-fii juofy;4 :an assume that the speed of the protons is essentially $c$ the whole time.) Energy/revolution =    MeV/rev

Show that the energy of a particl6*( unz:b jtzae (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 needed at the 1.0-km-radius Fermilab synceew/93c6e eqt,zqt* phrotron for 1.0-TeVte /qzw,ec6e *eqp3t 9 protons? B =    T

  How much energy is releasedpfe v t38yb gvvb5s/k kr0g fai)6/56z in the decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is r-2h ef -c:aj - ak.r0p4xxwremeleased when a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is required to produce8*1rrmnq psz( a neutron-antineutron pair?    MeV

  Estimate the range of the strong force if the mediating paovka0ld(/k jb kpz)d h- hs 5h/7,zc,brticle were the kaon instead of thezl zd akjksp5bo-,ckhdh b v/,0( )h7/ pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equal speeds. What mi 9sdl0/cp ;6fh p zlnq5f4w;zonimum kinetic en 6w pfz/d qh;4 ops5l9;zcf0lnergy must 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 neuthd* qtrr 3p)wnhxb)o7.(kh)irons each have if they are traveling at the same speed toward each other, collide, and produch 3(bkw .pnrtxr)7q* dhoi))he 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 theyf3 ypj52ay -+q1t)qhknt;wx masses of the W and Z particles as abouttqhxy1;p na) 3tf2 5y-j+yq wk 80 to $90\ \text{GeV}/c^2$. $mc^2$$\approx $    $\times 10^{-18}\ \text{m}$

  What are the wavelengths of the two photons produceuu7 tzagpo4l6l+ /5 mru :+hzwd when a proton and antiproton at rest gulhmrpl/u z745o :zu+at+6 w 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 impossible for an isol*k y9rgk (wvv9y65ez 1doeo4yated electron to radiate only a single photone4y96yz1 evk9w yo(*o 5 rvkdg. (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 photons produced when an electryr ifb( q5x)gf(mdps ,kk 1-a3on and a positron, each with 420 keV of kinetic energy, ann3gm1,)k k(-xiqp af5dsb (fry ihilate 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 ,. izw5du7eg a0vcx x7are possible? For those forbidden, explain what laws are v azcix5uw 7dev7 ,xg.0iolated.
(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 oag j:,s 5 :*rklppm2dff 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 k2hbh-xh2 aiji0 k*vq5inetic 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 width r8hpk x7jdk ;**r/5sej znjr +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 *3 ammv:aav ul/z a3dvqy6k84 $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width ofjzl7uu7d1i p01k0(i e pn2nvd the $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or uncertaintryf) a9q:uxt ,1)cuegy) 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 followingnjn-nn0cem wq 9us78 y )wjz4. 0x,eih decays are possible? For those that are forbidden, explainywqnnn w.c m- ez eih890x4)0n7u,js j which laws are 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 neutron,zrz knh-y;f*y9gre b 8(()ojh (b) an antineutron, (c9 jehk 8ogzzh*()bny; fyrr (-) a $\pi^+$, (d) a $K^-$?

What particles do the fh+bn-kdd.u ) gollowing 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 neeo(v. hzsc ;p k*sm weykzqs6.ww-19o( ded 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 Fig. Below) ftgg hlc8uk 2zd- 3*vxy /c,i4uor the reactiongv,/c-8*3l x ziydgkhu4 c2ut $p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for tbyp+ 7wak9xqep . qr. z4dis;+he reaction $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a proton whose kinetic e.kp*e;,f7hwbip k)r jnergy is 25 GeV? What is its wave r,eb pi)ph; kj*wk.f7length?
$\approx$    $ \ \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 Fermili;jy ho 67tq.uum: -alab Tevatron with an energy of 150 GeV. If they are accelerated by hqy6uumo.:ij;tl7 a- 2.5 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 releaseb 5*kekwfeya/ 6 3wm.cd when an electron and a positron annihilate each oth/ckabe53f ekw6 . *mywer? $E_{\text{total}}$=    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 interactihks;:q 9 6ljejon could they occur? For those forbidden, exlhj:j6 eksq ;9plain 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 interaci5ocgh k.wv4 oke 9.f0tion could they occur? For those forbidden, explain ki0.gc4eo.9kw vf5 oh 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 a pq*2gglj p5 o;e.t r2ay-3vdq$\pi^+$ is $\pi^+ \to \mu^+ + \nu_\mu$. What would be the equivalent decay for a $\pi^-$? Check conservation rules.

  Symmetry breaking occurs inmehxu 05er: ;ez9:sgl fs +:ky the electroweak 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 vq k9jxpajy q7zg-606 the reactions, Eq. 32-4, for producing a pion. vkg6 09j-ayq xjpzq7 6 $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value for the .scb dpvctf.wqkz,-2) 6 j1 upez4 c,hreaction $\pi^- + p \to \Lambda^0 + K^0$ 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 th7xcxvqo9 0/ k/ tqt6usere in a water molecule?    fermions

  A proton and an antiproton annihilate each otzb:+2q8l p5 mcsx6lrwqzdpbg9y64d6pu , y v*her at rest and produce two pions, ,4g6*zqz bm 6l 5:v+26dypqwp9l8pcdu y brxs$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called unification duzt-u) )wt p fwt-67fvistance 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, meag k6 tj+n*bi2jsured in a refer6n2*gkj+j ibt ence 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? $\Delta x_{\text{lab}} = $    $ \times 10^{-5}\ \text{m}$

Identify the missing particle in the fouxcl8gu xwy776/e/e71: h gjxfa v-z gllowing reactions.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to describe thiwnpkazy o1.s)c1e 75 e reaction $p + n \to \pi^+ + \pi^-$.

What fraction of the speed 5d5iwzm*lh d8tdrxwe 5()db) *;wvnaof light $c$ is the speed of a 7.0-TeV proton?