Give a reaction between two nucleons, sir;-h i4,2cxtlw 0lm nbmilar to Eq. 32-4, that could produce a n,cb- m0lw ;lirh4x t2$\pi^0$.

  If a proton is moving a88 2dv;yubp cot very high speed, so that its kinetic energy is much greater than its 8o cp v;u28dybrest 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 zo q (9gyaid32on)tj/to the constituents of normal atoms, consist of? What might happen if antimatter, made of such antiata dnzt9yo2g)/j3qoi(oms, came in contact with our normal world of matter?

What particle in a decay sizr/ s k7d45utfgnals the electromagnetic interaction?

Does the presence of a neutrino among the decay products of a particle 7f09f: gosq2vtwxt;d necessarily mean that the decay occurs via thgt;qx vf:fs02 d 9to7we weak interaction? Do all decays via the weak interaction produce a neutrino? Explain.

Why is it that a neutron decays via the weak internss 4w*.c+na yiv x)2aaction even though the neutron and one of its decay products (proton) are strongly int24aw)ysx+ vcnn. isa*eracting?

Which of the four interactions (strong, e1r).yw zn zo8qlectromagnetic, weak, gravitational) does an electron take part in? A neut.on1y w) zr8zqrino? A proton?

Check that charge and baryon number are conserved in each of the decays in Tau(6j hj9 b5atuble 32-2 5h9a 6u(tujjb.

Which of the particle decays in Table 32-2 occur via the vn()nlg/ j7zo6p lg7uelectromagnetic interacnnojg7l /lv7u) z( pg6tion?

Which of the particle decays in Table 32-2 occur by the weakpd7*+wdxue- 6fw f( t(ool1pb interaction?

By what interaction, and jw :(n)zu) erowhy, 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 particl5 sppg srpffi q+4- h.qlb83,*h3nb sle decays in Table 32-4 occur via the electromagnetic interacp3l-pbq,+fsb3sl i5*. f8pnq 4hg rs htion?

Which of the particle decays in Table 32-4 9tes0ilkgi06ip q8 tihf4 s 4jz+0c i8occur 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 ki n;w1t yv-rub8nd of "neutrinolet" that was massless, had no color charge or electrical cvu; -81wy bntrharge, and did not feel the weak force. Could you say that this particle even exists?

  Is it possible for a particle ,f; sm1x*fm:ny q3zha 0uy y0.jbk0c lto 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 powa ola0/*omnu0b *re1;p0 re qssible to find particles made up of two quarks and*pe/ua* 010;oonaq0rreb wl m no antiquarks? What about two quarks and two antiquarks?

Why do neutrons decay w) uqgi6 ojq2. d2,cwthhen they are free but not when they are inside the nucleus idjht6cu)g2 . qwo,2q?

  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 wh p86c(97um0hp hnizyz4w2xycose kinetic energy is 6.35 GeV?    GeV

  Calculate the wavelen7ro.m*cka bh. x*eh oh7qb:;sgth of 35-GeV electrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cyclotronsvq7vcj* .4 :d czrr (ukra)x+ in which protons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one complete revolution for a very high-energy zkqo1)5z2u i kproton in the 1.0-km-radius Fermilab accelerator? T = 1koz2qi5 z)u k    $ \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 adc4 r5qkn rrpb.0en*6y3v 1 jtccelerated $\alpha$ 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: 3gu -dhe)*, e/,qvdewu0-MeV alpha particles or 30-MeV wdhu *ee)dueq,v- g/, protons? Compare each 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-xkwep; 8u3 (o6u rbqqny revolutions do protons make to reach a kinbq o3kp-uxuw 86;eq( retic energy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelength* p l5rytp;y.r ($\lambda$, 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 accelerate deubvqci+xn ;e q l0.t;g:terons ($^2\text{H}$, 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 magnets for the Lawh/ipd z/sa 16rge Hadron Ca /1hpiz6d w/sollider (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 about 20 seconds+ gy42 phyvy)xq 4nge,3ly bs. to bring the energies of the stored protons from 150 GeV to 1.0 TeV. The acceleration is done once per turn. Esgyn )lbs, 3q4g. +4xpye2yyvhtimate 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 p3 s*tby u.3hnof a particle (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 Ferg,/h) yi gmo,tmilab synchrotron for 1.0-TeV protons? B = y,, )ho/ ggitm   T

  How much energy is rwh15 vd6ryv q:,b kwe9eleased in the decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is released when a 8n+.i4rai/-ep8(zgjrr tml h $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is required to produce a neutron-ant6dsj/oz -xrt l.7xkijx34yz0ineutron pair?    MeV

  Estimate the range of the strong force if the mediating par6jfca;v./bskaa2aq /ticle were the kaon instead of the pioajakcv f6s .;baa q2//n. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equal speeds. What mink n*,k:g h9fus xi nw)d01c/rql )6 ofzv5ax(eimum kinetic energy must each have gk n5wv1xcs9 fqok,d0e)n/zhfr6 l: (*)xai uif a $\pi^0$ meson is to be created in the process? (See Table 32-2.)    MeV

  What minimum kinetic energy mus;z:w-ql;b xb kt two neutrons each have if they are traveling at the same speed toward each othe;zl:;kq bb- wxr, collide, and produce a $\pi^0$ pair in addition to themselves? (See Table 32-2.)    MeV

  Estimate the range of the weak for6s2-0n ac r2z3dybsamce using Eq. 32-3, given the masses of the W and Z parabm 2ss-y ardcn6z3 20ticles as about 80 to $90\ \text{GeV}/c^2$. $mc^2$$\approx $    $\times 10^{-18}\ \text{m}$

  What are the wavelengths of the two photoo-dh-)-aqp -x6 5l5oyzwj cpw ns produced when a proton and antiproton at rest annihila-w-- h-dw5 ao65oz)cjpxyqlp te? $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 momen6v3 2,nu,npo mccyna/nc( u (ntum and energy, that it is impossible for an isolated electron to radiate onp/nvnunccuyc no( nm 3,,6a2(ly a single photon. (b) With this result in mind, how can you defend the photon exchange diagram in (Fig. Below)?

  What would be the wa1mow+ pdme2 gis: lw43no2b(jvelengths of the two photons produced when an electron and a pombod+:21jg 3molnw( siew p2 4sitron, 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 possible? For those forbiddenmh0;v5 qrg-i o brfx*;bqk93v , explain what laws are vgxb0 v3ovkhqirq mf; 5 ;*-br9iolated.
(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 eaca1;d ,9c cfv7p(k xmioh 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 electron64ux3gaa qblmxi1 z1- 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 esh vzwfj 6,fs2nt50t9a3q) vsov6dkp+timate 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 of thev; + inro; kmmm1fdyc,)i -*5)tnobtu $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width of o..shu :kmz 7m80 fbhethe $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or uncertainty)4vp,m oa +vx l4vy4ymm2+srof m(45 bn 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 ti1d, / vjy .qe.ac2kgw+lr0ppossible? For those that are forbidden, explain which laws are veacl0k/ q w, rg.21t.diyj p+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, (b) an anti.z.mwl er1k-c5 qut2m neutron, (c) a .wku 5q cmezr-2lm.1t$\pi^+$, (d) a $K^-$?

What particles do the followingmml v8v:s-fw( 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 com ch;x9a io2j(iq5 kn+ (;lksdxbination needed 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.ct: +,oxz4q. nvb3wax Below) for the reaction c3bx+, oxwq v4:a.tnz$p + \pi^- \to n + \pi^0$.

Draw a Feynman diagrad jiq2/iup ,n)zq/f6 sg1 da4o(cr 8zrm for the reaction $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a proton whose kinetic/e boo7gv:r 2r energy is 25 GeV? What is its waer2ob g7r /v:ovelength?
$\approx$    $ \ \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 ,fs5r6( etr* unuwq*, tz)r73 rijmxp1.0-km-radius Fermilab Tevatron with an energy of 150 GeV. If they are accelerated by 2.5 MV each revolution, how far do they travel and approximately how long does it take for them to reajz,56r3s(*t,*wmn eu tx 7frr )uripq ch 1.0 TeV? d$\approx $    $ \times 10^9\ \text{m}$

  (a) How much energy is released when an electron and a positron annihi5g : 4eejfkv,mlate each othg:f,ee5k m4jver? $E_{\text{total}}$=    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,5q *r8yr vo:fap*r yr.n5-o rb 6x zyp*m1si5s and by what interaction could they51 *:a*xvr i8 ro6o* -qy5mys z.snbrfypp5rr occur? For those 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 possible, and by what inter6h uttg l29d4az7gsfgj*0 synx081 rvaction could they occur? For those forbidden, expl 68sdg*xgl9h jg yzr4f2a v 7st0unt10ain 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 r; :rx;ac 98annm sih3$\pi^+$ 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 atet*8. yjnv5y+8y tk ze 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*qo4 hnhqq c7-b* )xjm producing a pion. n)*hq7qjox- mq*cb h4 $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value forif :ea+btf0/t 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 molecule? 95 og;bb)4.pymy cv)4tcwhz a   fermions

  A proton and an antiproton annihilate each other at rest and produce bgn:vuplurva./w1, u h17w z( opq60ctwo pions, 067r lv1ob,:g nw.h1up(v/uaqcwzup$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called unification disty fz9-1 numch0ance 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 p1 wywp42c jo0troper time, measured in a reference 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 aver1 wjotp0w2c4 yage, ignoring any collisions? $\Delta x_{\text{lab}} = $    $ \times 10^{-5}\ \text{m}$

Identify the missing partc0+g3shl o*lwu6aj 2ricle in the following reactions.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to desc (nvnxoo ay;4-,s ku c54-6rdm uk3nfmribe the reaction $p + n \to \pi^+ + \pi^-$.

What fraction of the speed of l1hd4 zdyw9,w aight $c$ is the speed of a 7.0-TeV proton?