Give a reaction between two nucleons, similar to Eq. 32-4 p2 g p6i9agn71lxyh+y, that could produce a + 2 ppl6gi nha17xygy9$\pi^0$.

  If a proton is moving at very high speed, so tha.wejv6- wrkb 8g gj8jng08cm9t its kinetic energy is much greater than its rest ener0mwvnj.6c8rg-8 89ewkj jbg ggy ($mc^2$), can it then decay via $p \to n + \pi^+$?  ----待选择----yesno 

What would an "antiatom," made up of the antiparticles to the constitc 5 y+uwnwa.o*uents of normal atoms, consist of? What might happen if antimatter, made of such antiatoms, came in contact with o.*n5aowu +ycw ur normal world of matter?

What particle in a de/v1q23uovx q2ayn) c vcay signals the electromagnetic interaction?

Does the presence of a neutrino among the decay products of a particle necessa.r fpc ae9)u(vrily mean that the decay occurs via the weak interaction? Do all decays via the weak interaction produce a neutrino? Ex (a.)u frpve9cplain.

Why is it that a neutron decays via the weak inqh jn wg.7 8fqxfiy-5z y)oa5 o/8cht(teraction even though the neutron and one of its de/y8h5nx 7g8)q(tf-ijz h c.w5q ofoaycay products (proton) are strongly interacting?

Which of the four interactions (strong, electromagneti3kzuz7i(uvdxlizr p bi l gd1;o76e 3-b g:*i7c, weak, gravitational) does an electron take part in? A neutrino? 7elz;du ii 3*bpio73vzxg1-: i7(lbd u 6rgk zA proton?

Check that charge and baryon number are conserved inenq2y im q9nuj4+0 y+q-qiu-m each of the decays in Table 32-2y+m4euq0qq-yu2 qni mj+ni9 - .

Which of the particle decays in Table 32-2 occur via the electromagnetic inmkm: kn5d( xc7loff2/ :sf 5wsteractio 5f:k/kw2 o5fxd7mm:n s fsl(cn?

Which of the particle decays in Table 32-2 occur by the wsco6ngk4f t028s 9vhj eak interaction?

By what interaction, 2h:v4j7t io1n n2 jzifand why, 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 Table yg.ery0yon s97/ j58 8vpl3 5twpkhub32-4 occur via the electromagnetic interactioklo p98e 7/gvpry u3yt55s. hwyn8 b0jn?

Which of the particle decays in Table 32-4 occur by the weak inter3j l8, 5u, czinxie)qkx1 ,velaction?

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.9v tht71 boay was massless, had no color charge or electrical charbo7h aty1.9tv ge, and did not feel the weak force. Could you say that this particle even exists?

  Is it possible for a particle to be both 9 u5 *41hz-6z(wpn:slmkkppp)ig nz s
(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 chromos5pj)vjwvq4y3q 4 5pr dynamics, would it be possible to find particles made up of two q pr4 4vs qyj35vwp)q5juarks and no antiquarks? What about two quarks and two antiquarks?

Why do neutrons decay when they are free but not when they are inside the ni+h:o uqnd5u.ns px74 ucleui sdn: p4 .nuu5hx+qo7s?

  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 wvebvu lptz6 e59372 tp,dfc2jhose kinetic energy is 6.35 GeV?    GeV

  Calculate the wavelength of 35-GeVst*eu hq1*r j) electrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cyclotron in which p qhh)z/ u : 5br;sgtl3/wm-nferotons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one complete revolution for a very high-energy proton in thnl+msc8gyxh 69 g+il.e 1.0-km-ln 8.y 9m+g+lh6ci sgxradius 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 Exampmq s1v nqn+g6jt5 +1v:,f* milq d6ijnle 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 parti8avtj 521 r,ahn0 dblccles or 30-MeV protons? Compare lbt5 2rvda1cjn08, aheach of their wavelengths with the size of a nucleon in a nucleus.  ----待选择---- alpha particles protons 

  The voltage across the dees of a cyclotron is 55 kV. How ma l1bdvd ouwd-.:t:c/bny revolutions do protons make to :-u bwvocl1 d:db/d t.reach a kinetic energy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelength (8u-2 ue81q gvq.x zfof )jyes8$\lambda$, 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 acctvkkgkn+ccxs)(y ug +e2 +c1kmgk +48 elerate 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 magnee6azdhd 2* n79ne0d ;qlr .bnnts for the Large Hadron Collider (LHC) calls for proton beams of energy 7.0 TeV. What magnetic field will be required7 dda*bnzerenq ;206 .n dln9h? B =    T

  The 1.0-km radius Fermilab T *gp qxu2s6:jbevatron takes about 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 can assume that the speed of the protons is esse:q *sjxup b26gntially $c$ the whole time.) Energy/revolution =    MeV/rev

Show that the energy of a particl2pmse47nz /nv e (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-rad8ikjit h;j19sius Fermilab synchrotron fht1i sjj;8 9kior 1.0-TeV protons? B =    T

  How much energy is rele)*,sf2rnh v acased in the decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is relhs*v)-r zupkc;lx ( :heased when a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is requiwwp5jk.nsai6u24w gsd)y8 n 6red to produce a neutron-antineutron pair?    MeV

  Estimate the range of the strong force if the mediating partht mk-wjf2:b,icle were the kaon instead of the pijmf wkb-h, 2:ton. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equal spe fnh3qlr4g0 (xeds. What minimum kinetic energy must each have i q4xh30(nrlf gf a $\pi^0$ meson is to be created in the process? (See Table 32-2.)    MeV

  What minimum kinetic energy mbo+ n--rv,:miku 7my must two neutrons each have if they are traveling at the same speed towar :vmy r-k7uni-om+ mb,d each other, collide, and produce a $\pi^0$ pair in addition to themselves? (See Table 32-2.)    MeV

  Estimate the range of the weak forctdr97 ai7;k vyct2z5ee using Eq. 32-3, given the masses of the W and Z pt; z52yi7t dervak7 9carticles as about 80 to $90\ \text{GeV}/c^2$. $mc^2$$\approx $    $\times 10^{-18}\ \text{m}$

  What are the wavelengths ep2.b/vtek/z y/m /em +sy aj2of the two photons produced when a proton and antiproton.//aevj2yeke 2 sybt/+m/z mp at 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 is imp7 hgsili(* m*/ tfjc,xossible for an isolated electron to radiate only a singlef*,sgh/it c7j* l( ixm photon. (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 produceb cg tz8p5e4f ihrk s9net624/xu n.b1d when an electron and a positron, each with 420 keV of kinetic energy, annisibe f2/p th41 cuxk5r849ne b t6gn.zhilate 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 pos6vnsp y4lg *1;ep fv*rsible? For those forbidden, explain what laws are violated. ppvgyrl1 e6* *f;vsn4
(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 producvmvj f ove*;1;ts 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*.f n 1 pmdm*uaw;(uyrn ,+kwg 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 estimate the e + hz8e cajp rti66ygg2ubz,:9t6sig8nergy 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 t: r. )tbau6d(va r/bx jnb1r7vhe $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width ofdu 5l,i72ci xi the $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or uncertp1/x: cuf3ygz)bgoqb yuu*tp;u- p 5 ;ainty) 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 followi)v*ve;ov3wh)-ys)x0v8 l w xu k+u 3oe9mouting decays are possible? For those that are forbidden, explain which lauwswt+h3o3o vvixyeu8*l o vm) ux;e9 ))0v- kws 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) d-r9v /hup s61d3je ega neutron, (b) an antineutron,p eh- e1g96rjduvd 3/s (c) a $\pi^+$, (d) a $K^-$?

What particles do the following k .loz(pf v54bquark 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 needed toh-zrf/btumn: (0e 8 ue 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.r:;ad * n,d5itlm h53bjtw a1y:jcog1 Below) for the reactiong*mchw1a:, 5yt3jjo1d: ib5;rtal n d $p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for the k ed.)vg5ntrwl 7h-)l reaction $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a proton whose kinetic energy is 25 mxd:je4w ai66o7nh ix0e(km0 GeV? What is its wavelength? a0m 0hi6( oekm 6xn e7i:x4djw
$\approx$    $ \ \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 Tb)s kh7g zq/w)evatron with an energy of 150 GeV. If they are ac7shb wkz/g) q)celerated by 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 released when an elect7l-d.9cuxc jvron and a positron annihilate each other vcjux9l7.dc -? $E_{\text{total}}$=    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 interaction couvp9-t s* dk0jold they occur? For those forbidden, expld-*tjko0p 9sv ain 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 interaction could6s1 )qosbfc w0ovsq25 hb4i 99vgo-vo they occur? For those forbiddoo)v9gi54b s1 wqbqso6 vo2-hfv 9 s0cen, 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 a7z f,8scpntp - $\pi^+$ is $\pi^+ \to \mu^+ + \nu_\mu$. What would be the equivalent decay for a $\pi^-$? Check conservation rules.

  Symmetry breaking occursqsr oxpcn8-,z pd/y5) in 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 reactions, Eq. 32-4, for producing a pion.b3k 5vuz+xp; oa;:uxhbu uo ;x5ap+;3z:kv xh $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value fo1 y4:l3w, 8eq,brv wm0zfg whts cu8y)r 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 a water myyq 2yc)-gu,s olecule?    fermions

  A proton and an antiproton annihilate each other atk ancbm-cbh w -0 ybfj;yw:,+hh35 za/ rest and produce two pions, bm 3-b0ch aky5naf:jhc;bh+yww z/ ,-$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-cahqefd70xv w tt /45se3lled 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 listedhfqak/m+r su2u,5az nio9 -t( in Table 32-2 are in terms of proper time, measured in a reference frame where the particle is at rest. If a tau lepton is created with a kinetic h9a, o+s-m(uraqktnfu52 /iz 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 following reactions. l unltb5i q;0ij/t4 k8
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to c wsq2+rl scj3nox,66eq* g1idescribe the reaction $p + n \to \pi^+ + \pi^-$.

What fraction of the s nlrc;:f0z0u.uq.sanql*fmek m tcw;-6 6 p1lpeed of light $c$ is the speed of a 7.0-TeV proton?