Give a reaction between two nucleons, similar to Eq. 32-9ojco k elegi(( )eh:*4, that could produce a g*:9ol ek jh(eo)ic(e$\pi^0$.

  If a proton is moving at vj-/ 4:vypjk us8 6fwvoery high speed, so that its kinetic energy is much grea-v8f/wujpj kv6s 4:yo ter 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 antphnja+ e4552o zrfc:oiparticles to the constituents of normal atoms, consist of? What might happen if antimajp+c r h4zn255 ea:footter, made of such antiatoms, came in contact with our normal world of matter?

What particle in a decay signals ):dxmx (q3xa,1c ox hjthe electromagnetic interaction?

Does the presence of a neutrino among the decay products o/l5r*mx 5ihmi ;tev:2oud w7tf a particle necessarily mean that the decay occurs via the weak interac; 5*/l2xmu 5whidv7ri:mt et otion? Do all decays via the weak interaction produce a neutrino? Explain.

Why is it that a neutron decays via f,vp ztn2.uu1 the weak interaction even though the neutron and one tuv,fnz1 .2puof its decay products (proton) are strongly interacting?

Which of the four interactions (strong,pz8tkb 8v /b-n electromagnetic, weak, gravitational) does an electron take part in? A neutrino? A protbv-8pkzbn t 8/on?

Check that charge and :bo*j/ jsqfwuh/ jr,7 baryon number are conserved in each of the decays in Table 32j,/bwo:u*/ s fh7rqjj -2.

Which of the particle decays in Table 32-2 occur via the electromagneot/ j2robr. br6hfx32 g n7np)tic interactip6. /x 2 rj)nrho2bgotfn3br7on?

Which of the particle decays in Table 32-2 occur by the weak i zt)0x ccdldp e,-v5d8nteraction?

By what interaction, and w hj*mfi z:ta 5tn,i)37kxesx:hy, 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 d*dqvww+xf vi7+ /uof5ecays in Table 32-4 occur via the electromagnetic interactiovwv+xf7udw fi/*5 q+on?

Which of the particle decays in Table 32-4 occur by the weak intbf( w5 orbxyjv:8 .,jneraction?

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 colldhz ;y9j. q1oor charge or electrical charge, and d .;9yhd1 lzjoqid not feel the weak force. Could you say that this particle even exists?

  Is it possible for a particle to be qr 7 kswqy(d,mcvq*e-(w jr0dt-k2s7both
(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 possible/qnyoi0tz*t9oae jdw6+ x 7- 6v4gyga to find particles made up of two quarks and no antiquarks? What about two quarks and two 64ajxg9y t0nge6z-*oi w7y+oad/ qvt antiquarks?

Why do neutrons decay when they are free but not when they are inside th z ul40*esfu9pe nucleus? u9zu4*ls0p fe

  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 6gcbh -qo 4* 50vf:mnqk)af fxis 6.35 GeV?    GeV

  Calculate the wavelength of vcm)vp8sjrl/+ z)by 2e .y5mq 35-GeV electrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cyclotron in which pr-w4wg(4z 7wo1q p hm hfne7kp2otons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one comcupba4b bnqg1 5- ke18plete revolution for a very high-energy proton in the 1.0-km-radius Ferm85b4u1 bn abp-ek1qc gilab 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 cyclotron of E ibh6xa/ba3 2dxample 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 ku .6 yyt:uz;p-)y6uhbu wu) oor 30-MeV protons? Compare each of their wavelengths with thpyb wy6u :)uuty okz)6;.-huu e size of a nucleon in a nucleus.  ----待选择---- alpha particles protons 

  The voltage across the d:rt .wv+u:pdz ees of a cyclotron is 55 kV. How many revolutions do protons make to reach a kinetic energy o:tz r:wvd+. upf 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelengt4 j1ro3lgp*;h p,mzqo0h9f2 q zrox +th ($\lambda$, 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 acce gyz-,vtb7l(j o xh8/qlerate 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 tunn/g zow36kjd o/ier)q0el that will be used to house the magnets for the Large Ha d 0gook e6/wji)r3z/qdron Collider (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 4tbil( +-ocyvtakes about 20 seconds to bring the energies of the stored protons from 150 GeV to 1.0 TeV. The acceleration isv+i 4l yb-t(co 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 (chur -je/;rxk 4marge $e$) 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 synchrovyxvu-k;-xc:qh-w atv 68;5enjp;q s tron fj;tv v6 c;q: v-w85-e-yksaxq;xnpu h or 1.0-TeV protons? B =    T

  How much energy is released inf(lma*xaq*wdt g ;47 x the decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is released when c/h( 9.wxcov3sf75zw/kh pdv a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is reu e6 fy0o8lo0cquired to produce a neutron-antineutron pair?    MeV

  Estimate the range of the strong force if the mediating partl6bf sfq bun ir-*wb7b:; )n;qicle were the kaon instead of the qr b6nb;: u- wn*fbifb7;sl)q pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equ-bsknwce/8w ewengh6 7 gb8 56al speeds. What minimum kinetic energy must each have ifwb ng8ew5 e-hs7/ b6w 6cekng8 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 if they are tra2f((w5doo,9 sj yp /xlfp ak98(xdihr veling at the same speed toward each other, collide, and/xdp(pois52,jao yx 9lh(9wf( fdr8 k produce a $\pi^0$ pair in addition to themselves? (See Table 32-2.)    MeV

  Estimate the range of the weak force usovx *xn0ms 8g0ing Eq. 32-3, given the masses of the W and Z particles as aboutgo 0x0xsvmn *8 80 to $90\ \text{GeV}/c^2$. $mc^2$$\approx $    $\times 10^{-18}\ \text{m}$

  What are the wavelengths of the two photo hfjzu/iv8(,hm 3zdh3ns produced when a proton and antiproton at rest annz ui8hhfdj( m,vz h/33ihilate? $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 6*asskpyw- u 1is 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 in (Fig. Beluys*sa-w 1p k6ow)?

  What would be the wavelengths of the twgh p pv9o5: s4c .19f.geu0zxgy5xkmpo photons produced when an electron and a p .mkgux zs5vp pc.4h0g519yxf:p9 goeositron, each with 420 keV of kinetic 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 rea:2r 3ixsdw l;fctions and decays are possible? For those forbidden, explawx;3d:2 fril sin what 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 energy of each of the two products in - xsoe y59 ex+szbult2;8b+ycthe 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)tfjl3sf7m7o7 3 osec 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(wo:vu2(5n on8gtnhzh d 80ix 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 thexc:xua+8 t9 ma $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width of thz obkk4m (w:m+e $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or uncertainty)(v lbble/ /-vg8c jufet 3hmva6+kjo0pyh6 ,, 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? Forj (ufdmu(+8w j those that are forbidden, explain which laws are vi u+jmdj(fuw(8olated.
(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 thatn7c;q djwwnv6f)f .j5 can form (a) a neutron, (b) an antineutron, (cvnfjj dn;6)q.75ww c f) a $\pi^+$, (d) a $K^-$?

What particles do the following quark combinations pksx-. urb+q sqm6dk :,roduce: (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 prodju /ltheyrewn2 ba64.pd,5i3 uce 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 (ae-e ufvbf(xi0yws0 - )s in Fig. Below) for the reaction v0 e)esxi0b u-f(wyf- $p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for the reacgpy w8 j2+i3exigjh *mmd3) +ztion $n + \nu_\mu \to p + \mu^-$.

  What is the total enez9( p g ng1y1 ryrr( p9b3u7ixhv3xl*xrgy of a proton whose kinetic energy is 25 GeV? What is its (rr9xppy3nhz(* by 91gui7 lxg13vrx wavelength?
$\approx$    $ \ \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-radcw5)rf xwa9 8 5ffhst3ius Fermilab Tevatron with an energy of 150 GeV. If they are accelerated by 2.5 MV each revolutiofws3 rawh)t95 xc8ff5 n, 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 4 yf8sy ,au:hvq-p;mdis released when an electron and a positron annihilate each othy:afm8 -su;, yqdvp4 her? $E_{\text{total}}$=    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 w t6uj;dcq/an:l uj1mq0+m ,yshat interaction could they occur? For those forb+jmua, d qy tuq 6;1c:sj0nml/idden, 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 what interamv/i0j )jco9 yction could they occur? For thyv io 90m)/cjjose 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 a o: cjl31 ;bxdm$\pi^+$ is $\pi^+ \to \mu^+ + \nu_\mu$. What would be the equivalent decay for a $\pi^-$? Check conservation rules.

  Symmetry breaking occurs 1ub edc mf;;u2wc1q fp+n5/ha ouy2( jin 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 the react g/eudc+u/ef 1ions, Eq. 32-4, for producing a pion. ef1 /c+gdueu/ $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value for tj.np4;kmu nq 1he 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 zycsyf b*f2086)y 8wfpw *fdpf ;cq 0dthere in a water molecule?    fermions

  A proton and an antiproton annihilatq(sd 0 i shpz(y g/a .cy4;xqx.a+w6xq*q -jpze each other at rest and produce two pions, sw(y-d 6p qx0;q/+ j gz.zxxh. iy*p4qsac (aq$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called unifi6yoiasj8fol8 4-fe c5q ;z/hication 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, measurend*wixvx4 q 4x +hq/f0d in a reference frame wherxvw 0i+qdhf4/xx4* qne 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 foynr m3o,fixt +v 2d7bi);ym0 ollowing reactions.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to describe the reactiok;3oded .v/x xn $p + n \to \pi^+ + \pi^-$.

What fraction of the speed of lgyr 08 2l-ab py0d iwrxyp:e4tv2-/m fight $c$ is the speed of a 7.0-TeV proton?