Give a reaction between two jnc *y5ydlh2fu2zs:p (:sy y5nucleons, similar to Eq. 32-4, that could produce a d:: l5 yy(z y5h2 upsfnycj2*s$\pi^0$.

  If a proton is moving at qj 0 ts8llx+nq15btm. very high speed, so that its kinetic energy is much greater than its rellj5nb t +t80 xmsqq.1st energy ($mc^2$), can it then decay via $p \to n + \pi^+$?  ----待选择----yesno 

What would an "antiatom," made up of the antiparticles to the consti u+zhl 9 jc5b/wwsy.(vtuents of norm.(5l sw+j y/b9chu zwval 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 electromagnetic interac;/n :t7v bscyztion?

Does the presence of a neutrino amony.p+dwg uwl 9xcoq9)/ g the decay products of a particle necessarily me .cdowy gw9x+/l) qup9an that the decay occurs via the weak interaction? Do all decays via the weak interaction produce a neutrino? Explain.

Why is it that a neutron decays via ry4hq4/. 9sitcj6kvm the weak interaction even though the neutron and one of its decay products (py tqm9ic.4kv6j/h4 srroton) are strongly interacting?

Which of the four interactions (strong, electromagnetjqd)n)l: j nl0ic, weak, gravitational) does an electron tak0j)nl nqjl:d) e part in? A neutrino? A proton?

Check that charge anc 11r4-fh 4bvnfhobo) *t*hbg d baryon number are conserved in each of the decays in Table 32-2fhoh *)*ncvbg r1th4o-1 f4 bb.

Which of the particle decays in Table 32-2 occur via the electromagnetic inek tk )zpq4sy+v k823jteractiope2v4 )s3ky t8k +zqjkn?

Which of the particle decays in Table 3r*bgfb,,8/9c xa 3l4 sljmedw2-2 occur by the weak interaction?

By what interaction, and why, 1 k;b x3g8ma 9lklbd:.gjyi b: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 q ,icd/*)ks+jq,vjv h z2lap ;Table 32-4 occur via the electromagnetic interacpc2* z,iadl vhjq , +k;s)vjq/tion?

Which of the particle decays in Table 32-4 occur by the weak inter:;gos4 pyc6 jfaction?

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 lg4fz.xgk z54 kind of "neutrinolet" that was massless, had no color charge or electrical charge, x4lgzk 5zg.f4 and did not feel the weak force. Could you say that this particle even exists?

  Is it possible for a particle to be(i 3jo,,kmt. 0fh3obyfz otlbhz0)b; 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 possiblqui2xs684 e teqinq .:e to find particles made up of two quarks and no antiq.eqit usxi2 4n:q8eq 6uarks? What about two quarks and two antiquarks?

Why do neutrons decay hc9 fl0+wnzwicc;4;hj5q (+ijejl r2 when they are free but not when they are inside the nucleusccj (hqj0jc; i wlhzfi4 +nw+l592;re?

  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 i8f( bzshnfrj62bpy) ;4 ud i/5oms 3xos 6.35 GeV?    GeV

  Calculate the wavelength of 35-GeV electrolbu18,vw6myo n gs w,5ns. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cyclotron in which protons m wg9;.6zch 5nst .l0g4c euptdake $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one complete revolution for a very high-energywn ,, 2ok 5r 6dx7og8bj/cuwca proton in the 1.0-km-radius Fermilab acckx 26ugb,/ ajo8d7w5rcncwo , elerator? 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 accelerate2lao4bk0. f cr.mi5kmd $\alpha$ 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 de pai*z bfv;3 jb1fs/w7tails of the nucleus: 30-MeV alpha particles or 30-MeV protons? Compare each of their wavelengths with the size of a nucleon in pv* 1i fb3a s/w7bfj;za nucleus.  ----待选择---- alpha particles protons 

  The voltage across the dees of a cyclotron is 55 kV. How many rinz ; t-mpe voz 6wktu-ur**69evolutions do protons make to reac;9v6m-uz -z*iu 6knpo ttr*ewh a kinetic energy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelengtcu iememn,3;8 h ($\lambda$, maximum resolvable distance) of 7.0-TeV protons? E =    $\times 10^{-19}\ \text{m}$

  A cyclotron with a rbga kng83z m+qgoc :8+adius 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 gwa 6rz+rrxqg*;1 n(whouse the magnets for the Large Hadron Collg+ w(* w1nq6garxrz;rider (LHC) calls for proton beams of energy 7.0 TeV. What magnetic field will be required? B =    T

  The 1.0-km radius Fermilab To- 0y(w go sgrp)-dcg:evatron takes about 20 seconds to bring the energies of the stored protons from 150 GeV to 1.0 TeV. The ac :-pr gcoyw -0dg)(ogsceleration 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 fgmz/ 0js1x/ u$e$) 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 intensitiw i,)8u 3mgwuj4gyn19 ;t16s(sbb 1w nquhbty is needed at the 1.0-km-radius Fermilab synchrotron for 1.0-TeV puw , t;b thwqb1g9bjs1u8s3 w6( guinmn1yi)4rotons? B =    T

  How much energy is released in hyb i+qhsw +9oq *f:o.odt)o2the decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is releal- ld2z 80arx3szq+ taus u-2tsed when a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is required to prodt.z/sl s hr.7fuce a neutron-antineutron pair?    MeV

  Estimate the range of the strong force if the me hih)(sbf 78-,gsjk9q7 cf jmrdiating particle were the kaon instead h97 qfs-jcmsgki,7j r)h fb(8of the pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward ea; 5 answv0pv5ach other with equal speeds. What minimum kinetic energy must each ;p50nv va 5awshave if a $\pi^0$ meson is to be created in the process? (See Table 32-2.)    MeV

  What minimum kinetic energy must two neutrons eaeh b z1s:u;a3q 5k.yyqch have if they are traveling at the same speed toward each other, collidqb:y y1q.z 5aue;3h kse, and produce a $\pi^0$ pair in addition to themselves? (See Table 32-2.)    MeV

  Estimate the range of the weak force using Eq. 32-3, givzinq)cvvdiim:oo0 ./ c3/8lh en the masses of the W and Z p 3v.i8:m vnlcqcdi//) h0 iozoarticles 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 and9q s,n,t r4 tlh)b 5vou,7vbwx antiproton at s,,o7qwvx, tt hv5ubl9r 4)bnrest 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 (9l p ar2e 4ar7t vt;ety.9bx/pq0gvtand energy, that it is impossible for an isolated electron to radiate only a single photon. (b) With this resu rl.0tva;ee94ab2 t 9pt /x(ryqgtv 7plt in mind, how can you defend the photon exchange diagram in (Fig. Below)?

  What would be the wavelengths of the two photok-a91odw3 s kqx0k3 vfmyp8i* ns produced when an electron and a pax 8ywosm9*k3ifq1v-3d kk p 0ositron, 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 reactions and decays are poss) 5y,x-pfd wz0sry)wp ible? For those forbidden, explain what laws are viol-wd5) w)zf,ryxsyp 0pated.
(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 dxou-6p9 .qj sut4 mj1decay $\Xi^- \to \Lambda^0 + \pi^-$. 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 en+z;)j (xpzx m: nklgr9p p8+,cd*rzkkergy 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 widti8,ppn vb:z1 ohv9o24w0 4jiwja nzb*h 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 ofxb95x;(gr;q sx pp1si the $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width o: z4uw2)wk di4jh(gfd f the $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or ips 1am jqfr /8nq+2+kuncertainty) 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? Forolop7h sjz c59nh(:t/y,bmh 5 those that are forbidden, explain which laws are vhcoo s,5:7tzhb/(m h5p9 lynjiolated.
(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 neug/b :gbv+em:i tron, (b) an antineutron, (c) be+g :/ivgmb:a $\pi^+$, (d) a $K^-$?

What particles do the following quark combinations produce: (a) -*a 2ullpk+jm$uud$, (b) $uu\bar{d}$, (c) $u\bar{s}$, (d) $\bar{d}u$, (e) $c\bar{s}$?

What is the quark combination neqlcxr)n8 mi)-3l6kvlp* is4ueded 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. Belowsnv96lq+byar; 2 ji, 5ojrvy*) for the reactionjq n,b2a5i s 9jl;yvyrv6+* or $p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for the react8:2) 6gulug0gr qaq avion $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a proton wf7t9/p4:xs2 a sqf13cxau v rjhose kinetic energy is 25 GeV? What is its wa qx9s:j /a34fvutascx1 fr72pvelength?
$\approx$    $ \ \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 fxxd/6(to. rkb6 qj)k into the 1.0-km-radius Fermilab Tevatron with an energy of 150 GeV. If they are accelerated by 2.5 MV each revoluxrqk/odb.6 j ()tfk 6xtion, 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 ws(ryw h c-9b p+a9y6bpositron annihilate each othe9( rbysyap-w6b 9+ wchr? $E_{\text{total}}$=    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, am8bld :/ ru;v+xe(tsl nd by what interaction could they occur? For tho;u e/+lxm( sd8 tblv:rse 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 possi cnhnvjl /i-i/e3c :z5ble, and by what interaction could they occur? /vniiczl-e :jc3n h/ 5For 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 al+ fxw+yqs)tviqpq* rt+oa6 et.s8,/ $\pi^+$ 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 aboutu9 l4gtvfn* l, $10^{-18}\ \text{m}$. 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 t0cul t4mc2x9dg( 3hvdhe reactions, Eq. 32-4, for producing a pion.0thdx um( 2d3g4cc9vl $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value for the)nl3 fioz+te. 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 molecule? sd u:xo zhfd/2+je94s    fermions

  A proton and an antiproton annihilate each other at runk u;qtq i/8q8:ek 9rest and produce two pions, qe/qt kkinqru8u 8;9 :$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called unification distanffh*0fk,yu/i7m/37x dighu +r xmob2 ce 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, measured in a ll)gp8y*e 3fb reference frame where the pafply*3g b 8le)rticle 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 fosnqkunw 0g*x45d, +v g77eqv. vly)frllowing reactions.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to des mf*xtwuiw)wu: d1v5)dx58qo,q a0uwcribe the reaction $p + n \to \pi^+ + \pi^-$.

What fraction of the speed of xhz3( kf;hr /ia6lsy- light $c$ is the speed of a 7.0-TeV proton?