Give a reaction between two nucleons, similar to Eq. 32-4,da vy9x**;wb jk-uqar4d 5zs- that could produce a 9* rjdqzu*wa-; bk-ay d4 svx5$\pi^0$.

  If a proton is moving at very high speed, so that its kinei4va v78 lmfmy4lu2.r.)yxgktic energy is much greater than its rirl72v m. mf4lu8v)x k.4agyyest energy ($mc^2$), can it then decay via $p \to n + \pi^+$?  ----待选择----yesno 

What would an "antiatom," made up of the antiparticlesv7wtxn+vev: :xbdb46 to the constituents of normal atoms, consist of? What might happen if antimatter, made of such antiatoms, came in contact with our normal world of mattebnvewv6xb :d4x :v +t7r?

What particle in a decay signals the elec /;b07w-u w,bkm xf3np )tu/lt7qqbnstromagnetic interaction?

Does the presence of a neutrino among the decay products ofvnoq)1n f k33b a particle necessarily mean nnob13qk 3fv)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 the weak interaction even though the neutrod :p+f3b xs(edn and one of its decay products (proton) are strongly in(+db fx:esp 3dteracting?

Which of the four interactions (strong, el+;klnnw6zkjm 9lz s.4ectromagnetic, weak, gravitational) does an electron take part in? A neutrinokl4k j.9sz;nm6n zwl+? A proton?

Check that charge and baryon8) ;sdf *f2u(4ihb n( og:gpwsna1bht number are conserved in each of the decays in Table 3ah; tn8os4* dn(u1wbfp:ifh2s g( )bg2-2.

Which of the particle decays in Table 32-2 occur via the electromagnetic intepe 13epxm ;by9ractioem p1 p93y;xebn?

Which of the particle decays in Tablm2kq8 +ekyjg)e 32-2 occur by the weak interaction?

By what interaction, and why, doe1*pw4xo gmr1 as $\Sigma^0$ 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 Table 32-4 occur via 7h*towz zzdu m.qb 6r6zd.+56mlroc0the electromagnetic interactiozq0* zd6um wrz6zohc76 l mdtb +o.r5.n?

Which of the particle decays in 9wabg/rpr 8q3itc 3 k:y*:yhava):ifoph/)bTable 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 "neutr e) yqvnvk/5gp2 :0qxjinolet" that was massless, had no color charge or electrical charge, and divgkynx2 eq:5 )v/j q0pd not feel the weak force. Could you say that this particle even exists?

  Is it possible for a particle to be bo:m5sc tp1 3mrgh h *7+ldvboxw;.5f jjth
(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 to findo v 8wa7)oiw2udf zik +p7;8sb particles made up of two quarks and no antiquarks? What about wv ozdbu i28sfi; )w+o 7k78patwo quarks and two antiquarks?

Why do neutrons decay when they are free but not when they are inside thczv.; 2w0c(sno lt hq)e nucleus? ctow(scnh q2v0.z )l;

  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 protohi8ju*)p qd fs9k16i hn whose kinetic energy is 6.35 GeV?    GeV

  Calculate the wavelength of 35-GeV eleu d6*a ,lbjoxrc+f42jh* udx*ctrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cyclotron in whi6jcab*3o6 bd s(h5-rl+ urjudch protons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one complete revolution for a very highf teajs m56(p1-energy proton in thepfe(16t5 m jsa 1.0-km-radius 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 cyclotron of Example 32-2 accel y3)0cmp sf5wperated $\alpha$ 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 nucl9g p znwzck0q3r -6q:veus: 30-MeV alpha particles or 30-MeV protons? Compare each of their wavelengths gr6 z:cz39-v0p wknqqwith the size of a nucleon in a nucleus.  ----待选择---- alpha particles protons 

  The voltage across the deesp+q4/ sz uy+yasc9 ixi 5v/c2ockw/p2 of a cyclotron is 55 kV. How many revolutions do protons make to reach a kinetic energy of 25 MeV? 2 /z4pyuc/x+i qyw +5isckc/v as92o p$\approx $    $\ \text{revolutions}$

  What is the wavelengthipsh k 3k2cyooj.. c;.r wh48n ($\lambda$, maximum resolvable distance) of 7.0-TeV protons? E =    $\times 10^{-19}\ \text{m}$

  A cyclotron with a radmj rs) glw*)7wius 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 usdsxbof7wp nqe, pw5 p8n./ 0(ged to house the magnets for the Large Hadron Collider (LHC) calls for proton beams of energy 7.0 TeV. What max p/7 wwsn.p8febpdnq0 (o g5,gnetic field will be required? B =    T

  The 1.0-km radius Fermilab Tevatron takes about 20 seconds to bring tv u w7qu46x6qqst3 tm(he energies of the stored protons from 150 GeV to 1.0 TeV. Theqv364qqwxs6t m(7uu t 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 paoot.8*mv)v4 qir ocintm1 (2q rticle (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 qr/g1sibwl3i z qy5l/0w,ab(the 1.0-km-radius Fermilab synchrotron for 1.0-TeV protons? ay3wzsql// l05rw q(gi,1ibbB =    T

  How much energy is released in the dec vk0 y e/d1 54*emd+z)i(c*fuhtsmow oay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is released when a q-(jo.x5edt v$\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is required to produce a neutron (,ejoq9 g7q.lvfpkv8-antineutron pair?    MeV

  Estimate the range of the strong force if the mediating parturl;dxk 1 u28s(h0nralf *6mm icle were the kaon insu dum16nsrf(*mrl;a82 lh kx0 tead of the pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equal speeds. What minimum edd 21u5kdx:t o6xx (qkinetic energy mu ku6xedx(dt 52oq1:d xst 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 neutrons each have if they are travelj v oi2j,i+.tqing at the same speed toward each other, collide, and produce ti.j +vo,jq2ia $\pi^0$ pair in addition to themselves? (See Table 32-2.)    MeV

  Estimate the range of the weak force 7 -vlwe qy)/y.hbeng1wzp6;yusing Eq. 32-3, given the masses of the W and Z parte7;g hepq/b1 lynwv.)wy- yz 6icles as about 80 to $90\ \text{GeV}/c^2$. $mc^2$$\approx $    $\times 10^{-18}\ \text{m}$

  What are the wavelengths of the two photonv:skp(o : tpe.s produced when a proton and antiproton at et(.:spk pvo: rest 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 *9hk eo6.soqo is impossible for an isolated electron to radiate only a single photon. (b) With *69sqhokoo.e 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 el).; kpwzi )a m5ozhjf4ectron and a positron, each with 420ja;z)i wmhzf)5k.po 4 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 possible? Fol** m;eq tpztz-vrl9ote 5:;t r those forbidden, explain what lae-*zpt :tqmzlo9tt*ve;l5r; ws 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 kinetic4lih pub*xbt70 +jc( ub ph4)zxz6h(z energy of 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 kinetic energy of the electron in the dstbx9t pxfeop+3o;;j 0jd 8 6becay $\mu^- \to e^- + \bar{\nu}_e + \nu_\mu$. [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 x0rng5l3t ttwo;;hxk wqa32 p98c.lwestimate 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 of6ghw)+ f ze2rx(cgns4 the $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width ocmz) blsa9 zvf2t- yvw,l;),cf the $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or ; v2wiq4ib(dh uncertainty) 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 followiauad :u74w l eayu890ing decays are possible? For those that are forbidden, explain which lawl7:uu84aw9id e0aa yu s 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 combinat *l+ps,. uangsions that can form (a) a neutron, (b) an antineutron, (cgu.,+ *a lsspn) a $\pi^+$, (d) a $K^-$?

What particles do the following quark combinations pr3 0d gfpq 7yk8 p--evvb9ol0aboduce: (a) $uud$, (b) $uu\bar{d}$, (c) $u\bar{s}$, (d) $\bar{d}u$, (e) $c\bar{s}$?

What is the quark combination needed tejlu ctj n/t)v0jo.2+o 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) for the reacti.t(c3*ih+o 4zsk.j fmi ae xn8on*i(ce x ka.s tminf jo+z4.h38 $p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for the reh),tbx14adc+ 5(rw ao o1xntnaction $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a proton whose / n,ekv 0xsl ncoy)+0)ycrp0r kinetic energy is 25 GeV? What is its wavelengtl+/)s 0c roxc0)ykyne0 ,pnvr h?
$\approx$    $ \ \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 Fermilab Tevatron with an egqh7p6 cgo)2r3: o hgfnergy of 150 GeV. If they are accelerated by 2.5 MV 7 3gcg2gf q)o6hp:horeach 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 releah9*bxzx 4db/dbg 1t3dsed when an electron and a positron annihilate each otherb*4xd3d /thx9b1dz b g? $E_{\text{total}}$=    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 ;v)f b+fe zt8beb u8p;what interaction could they occur? For those fv z bbftp8f;u+ee8;)borbidden, 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 poss(j :z* smb-m(jcyhp24ub) rt lible, and by what interaction could they occur? For thosems-t2p4jmc rlzh j(b(*u y:)b 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 g.nylg5 5ix;z7k+v if $\pi^+$ 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 cdv n v1/wefg)v(wp5mrvier7*u8*r4about $10^{-18}\ \text{m}$. 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 reacpw u2m f8w.wx g;eh8/xq s0g1ttions, Eq. 32-4, for producing a pion. u1 g0f8 xht8.w2wqp;wxgems / $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value for thefxbq 6 .besa3h/rln+sm )8-at 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 arewatypx1/kg)3eg)l(c4yua7hf7zx+ e there in a water molecule?    fermions

  A proton and an antiproton annihilate eachx-k rgq56w23txbg f o; other at rest and produce two pions, x 26f53 g wrokqxbt-;g$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-) sqpwrb qbfg,l6c5,)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 prope lq*wmxl8le;k2 s+ ,ber time, measured in a reference frame where the particle is at rest. If a tau lepton is created with a kinetic energy of 450+s l; ebl,ek*8wmxq2l 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 reactiojk0;nyutr* g pioib7,j0a(+/cy: n dp ns.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model t9s.k 9t6ot blyfvly37 iwav +3o describe the reaction $p + n \to \pi^+ + \pi^-$.

What fraction of the speeew 1ansj)4o:ldjq 7zhs /56nxr,q sd3d of light $c$ is the speed of a 7.0-TeV proton?