Give a reaction between two nucleons, similar to Eq. 32-4,vhxxl*;:.p a e that could produce a hv ;x.:eap*xl$\pi^0$.

  If a proton is moving at very 77je1tfx9 v q:d26ni jj0(8fj pujejl high speed, so that its kinetic energy is much greater than its lnpx2efq(:vtijjj7u69e1 d8 j7f0jjrest energy ($mc^2$), can it then decay via $p \to n + \pi^+$?  ----待选择----yesno 

What would an "antiatom," made upq+-fi v.c a*rd of the antiparticles 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 matter?qf-dc ai.v+ *r

What particle in a decay signaz8/x9hg* 9i;tgi )9j2im q ytqwk l6ijls the electromagnetic interaction?

Does the presence of a neutrino among the decay products of a particle necess5rgcmvqt i0h:+n1-csarily mean that the decay occurs via the weak interaction? Do all decays via thq -gisnh0c+rv:c5tm1 e weak interaction produce a neutrino? Explain.

Why is it that a neutron decays via the weak i+d4.ji c5scg0b bua00 wzjn-fnteraction even though the neutron and one of its decay products (proton) are strongly interacting?0b0ccd. 0b fsn jz+w i4ja-g5u

Which of the four interactions (strong, electromagn*7 hk:b9:-oe8 ji8.jkl.0rnwzdn pzf r,vfqletic, weak, gravitational) does a,k o:rhlfjrl.vk .0w 9j8*fdei: nnqz8-bzp7n electron take part in? A neutrino? A proton?

Check that charge and ba/99xp. j uhgcdd fh,/r:(v3* vobsn8c zcm u;wryon number are conserved in each of the decays in Table v/vc3s ug8xd;phu:,b9/(9nd cw .fc* omz jhr32-2.

Which of the particle decays in Table 32-2 occur via the electr i10 ;spmhoz(uomagnetic interacip(0s1z m; uohtion?

Which of the particle decays in Table 32-2 occur by the weak int70:xag *n3fitncu)fd y((k xj eraction?

By what interaction, and why, doe;7f,jt l b :nhm7ll.nfs $\Sigma^0$ 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 the electroivj vy ,p84og.,n xr z+.+*khjosa qg6magnetic interactn 4vjzyo.k,g,xg.o* h+ji6pv q+r8 saion?

Which of the particle decays in Table 32-4 occur by the f w; cvgsswr.x *tpa 1kk;8to2xr6.7x 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 "neutrinolet" that was massless, had no c a;zm7i )mz1ntolor charge or electrical charge, and did not feel the weak force. Could you say that this particle inzt1a )m7 mz;even exists?

  Is it possible for a pau t6vh5s7 t:srb0 8 rsqe/8brxrticle to 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 qwm7s1 ( vcuupr+t.m1c uantum chromodynamics, would it be possible to find particles made up of two quarks and no anti uru71+.mm cv p(tswc1quarks? What about two quarks and two antiquarks?

Why do neutrons decay when they are free but not when they are inside the at.p8*3ptwl5y 1 yf kxew:dd6nucleus?w3 wx epk pfdl8 a:.y1td*y65t

  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 is 6.354.u cmk9tz1fl 11vdb g GeV?    GeV

  Calculate the wavelength of 35-GeV electr qjyw w(r8cks* u.2v/mons. E =    $\times 10^{-17}\ \text{m}$

  What strength of mag7 ty.j8q,klyj netic field is used in a cyclotron 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 proton*g5m) a4bl a)tu ensncb(;7 nts.kl)g in the 1.0-km-radius Fermilab accelerator? tk4 .asang;)gclmuebb())l 7 stnn5* 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 Examplzlmq7/ o;ik0v9y l1oqe 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 nuv;0tff* t 1bjucleus: 30-MeV alpha particles or 30-MeV protons? Compare each of their wavelengths with the size ofvt 1ffub t*j0; a nucleon in a nucleus.  ----待选择---- alpha particles protons 

  The voltage across the dees +as 4um4xha/ m vg23 9hqe3(mh8 bgcofof a cyclotron is 55 kV. How many revolutions do protons make he2sm8aqf(m 43 uhv4m3ch9ogg/ +abxto reach a kinetic energy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelength (ye1 bcuvgdpx( );myxae4 -w- ;$\lambda$, 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 deuteronx inbe1,0x(f j9dho3ys ($^2\text{H}$, 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 Lack -x4* nwo/nerge Hadron Collider (LHC) calls for proton beams of energy 7.0 TeV. What magnetic field will be req4x k*n-/wnoc euired? B =    T

  The 1.0-km radius Fermilab Tevatron takes about 20 seconds s1 qe-tpfo 9n:1n ghu3to 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 hn-11e:9 f3topnqugsthat the speed of the protons is essentially $c$ the whole time.) Energy/revolution =    MeV/rev

Show that the energy of a particle (chao3mnbk o rg6occoda 2p6 )*))grge $e$) 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 nk.g yojumksim t)8w1c,e3ck8* m* x1reeded at the 1.0-km-radius Fermilab synchrotron for 1.0-kcm s3i rkmkec*11j *8o)8wxy.t , gumTeV protons? B =    T

  How much energy is relwb3rbg rw ;odo 0k4f51yf:u4leased in the decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is rel14kz nm:jdhfpr-cj,zcf +6k :eased when a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is required to produce a neutr/z 9l tqvcaw. y9(jylmk j3*7k5 tnpvyks 9e88on-antineutron pair?    MeV

  Estimate the range of the strong force if the mediatiualq)tr ,70kmg )y25 1 ofapjsng particle were the kaon instead of theoq1f7ag2t0sj,la5)y )u mp kr pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equal 6v 9xx b8q7poganph12speeds. What minimum kinetic energy must91xv8xp2 7nqbag6hp o each have if a $\pi^0$ meson is to be created in the process? (See Table 32-2.)    MeV

  What minimum kinetic energy * (8 h lyhplhez(1yrokfoq.:a:on v(.must two neutrons each have if they are traveling at the same speed toward eav.fn( y:q r 1:* hl8((yekzplohhooa.ch other, collide, 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, given the macg9)ll lc)fs,ik s3u( ld 8u4ysses of the W and Z particful sul93dkcll4y ) ,() 8cgsiles 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 and an o42tw/lq4- zb(z y deqx(xjn/tiproton at y(oe24wqbzx4t /lz dq- ( jxn/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 impossible for an 1.gfd;i19 qs+cpjmfje k54 h5t bxz7jisolated electron to r. jc+5 ti971zp;b4j df5jk ex h1sqgfmadiate only a single 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 produced whvgrmx19-web4r: jr6 oen an electron and a positron, each with 420 keV of x:rg1mwrvje -6 r9ob4kinetic 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 forbidden,aw:* fpg-r5;is7l: jpm ) exot explain whatt:*ixm;f5r:g 7eoa p- swpjl) 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 each6v,5bx 8cujw ph .h*kl 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 :iy )m2-b5 n*uleqkj :i:mvpn 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 andev;/- bovei : 9qt+nwytmsdm pj031+q then the lifetime of the $\Delta$ resonance using the uncertainty principle.
$\Delta E$ =    MeV
$\Delta t$=    $ \times 10^{-24}\ \text{s}$

  The measured width o*1tf/rsr,q 5;s 5do yujef j8mf the $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width of the *j ms;qzu;8)+qg(l ue fbk 7df$J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or ; l,znzw+ru) ouncertainty) 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? For those that ab;3wq6g. qa xf(7wv yure forbidden, explain wh6g;qu73a bv (fw.qw xyich laws 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 forml9y3zj o) onkzl1khgf;mgj8( yw8 k7th5; p. t (a) a neutron, (b) an antineutron, (c) 7j.y895gh ;k)wpn t;f(8gzt zho1 myo3ljkkla $\pi^+$, (d) a $K^-$?

What particles do the following quark combinatii8vybu7 +/u eyons produce: (a) $uud$, (b) $uu\bar{d}$, (c) $u\bar{s}$, (d) $\bar{d}u$, (e) $c\bar{s}$?

What is the quark combinam0x x z,d8dow0tion 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. Below) fo-,o 3jqhjko,3oid: ck3 wt 7mxr the reactionj3o-3q t mj7odk,,:iw ohcx k3 $p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram fj5h i5iwy/ r;bor the reaction $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a proton whose kinetic energy is 25 GeV? What isn 6rl,4l2r/qnyi;fwgu+2pl v its waveleni/rulvyf,2qgl2wpn + l; 4r6ngth?
$\approx$    $ \ \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 rki/ua.qau*w7t:t g f 5ho *c5into the 1.0-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 reach 1.0 h./: ugc55*faut 7qktrw iao* TeV? d$\approx $    $ \times 10^9\ \text{m}$

  (a) How much energy is released when an electron and a positron annihilatmqpj79l *w5 kti /4rzge each ot tk/ r7lmpgiq*w4zj95her? $E_{\text{total}}$=    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 coumu2df: g,,ml0 pqgplhz ) 2/inld they occur? For those forbidde), ggipmhupqm:dl, zl /02f2n n, 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 reactionep+jmh /4srodv) +;p.1wc ad3e qve5gs are possible, and by what interaction could they occur? For those fosow3g4v a hed)mp/ v +ce +;d5.qejrp1rbidden, 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 akossg7ves-c9d x7s 2,vb 5hm 5 $\pi^+$ is $\pi^+ \to \mu^+ + \nu_\mu$. What would be the equivalent decay for a $\pi^-$? Check conservation rules.

  Symmetry breaking occurs in thmaz:6:paj i (ku4 dx.xe 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 producin xsrtn/id tgu,*s0k. s;ogx:8g a pion. dti ,: . sx*kg8 gonxt0susr;/ $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value fo5+ *pdg+ btlbjsrpw 69r 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 a/ lyi 9,yygp/xrhp7:j re there in a water molecule?    fermions

  A proton and an antiproton anni6g7fyr pigz6 xgwsr( 91. e042zlyutqhilate each other at rest and produce two pions, iy xp 2z19 (q66f7 ggrusez0trlgw4y.$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called unificaan 6a1 q(qorn285jgggtion 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 Tabim0sjfi),5xp8moawtr1 z5. 4jf 7hr sle 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 energy of 450 MeV, how long would its track be as measured in the lab, on averaii.5j ) 017jtmr f8romas whz,x 4sf5pge, ignoring any collisions? $\Delta x_{\text{lab}} = $    $ \times 10^{-5}\ \text{m}$

Identify the missing particle in the f,sdclus r,gm la8u8;u 9q c217u4 qcqrollowing reactions.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to describe the reacf5sy3dqbm(x.x8)j bmtion $p + n \to \pi^+ + \pi^-$.

What fraction of the s z.) acq:drpqfex 097aet ,rp1peed of light $c$ is the speed of a 7.0-TeV proton?