Give a reaction between /z5/o )yvr4gn y,ru *srw5cjctwo nucleons, similar to Eq. 32-4, that could produce a ,wr n)c 4g/y5 v* ozucyr/sjr5$\pi^0$.

  If a proton is moving at very high speed, so that its kinetic eu..i q ,fxtsu9nergy is much greater than its r 9qx.tu.iu sf,est 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 constituents 4 9(- /lrl-f;kwjomaj vsvje6 of normal atoms, consist of? What might happen if antimatter, made of suc -(-al;vs /j6kr lovmf4e9jwjh antiatoms, came in contact with our normal world of matter?

What particle in a decay svxzg)cxm v+r (kk 5z1-k1oh c3+n 6rttignals the electromagnetic interaction?

Does the presence of a neutrino among2dt63 vpkth h9 the decay products of a particle necessarily mean that the decd3t6hk p92thv ay 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 intezf 8ndl b+ qq9a 6:hrz-+bmy8oraction even though the neutron and one of its decay proyb lrn:zmo9 8a+ f-hq+8zd6qbducts (proton) are strongly interacting?

Which of the four interactions (strong, electromagnetic, weao.qwd : .h1s7 5wtisntk, gravitational) does an electron take part in? A neutrino? nod 1 w5tw:si7t.h.qsA proton?

Check that charge and baryon number are cons-;o stuq,3 bhdl90x. o 2ozmjjerved in each of the decays in Table hmsl ot,oz9bodx j2juq.3-;0 32-2.

Which of the particle decays in Table 32-2 occur6m)i1e/phx:w w2 nf5tvc* afw via the electromagnetic interaction?w pt1m w6cf2 fn5ix)h*a w:v/e

Which of the particle decays in Table 32-2 occur by zsf) vt m ,d:yg.va qg-z9:p0ythe weak interaction?

By what interaction, and why, doespf . o/72r hmq+vsig;q $\Sigma^0$ 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 electromagnet/u)4e4ql1czz 1i 7( +kwgp b8whlnc fsic interacti7qs c enl )kfcw+4/l8 z11i4guzh(bpwon?

Which of the particle deet d bc639t1rvcays in Table 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 "neutrinolet" o5n 8254b qwjypvi ,1mro uq,rthat was massless, had no color charge or electrical charge, and did not feel the weak forcb 5np,5v2 8rw4oyo,u qqj 1mire. Could you say that this particle even exists?

  Is it possible for a,w-7yncwjl5 -(2+a uda ocpsr particle 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 quantum chyx(y w zae9-o f uu)3qt)cw4)mromodynamics, would it be possible to find particles made up yz eu)u)9-t wo)mxcw yq(43fa of two quarks and no antiquarks? What about two quarks and two antiquarks?

Why do neutrons decay when they are free but np4m.e5uvy6 n + t8qccb b)ev aa(c(4srot when they are inside the nucleus?54nea.+6 (48mrvea sbc)cyvqp (tu cb

  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 adji3,en/jhu+iage0i *9 b yij ;w *a3il b1o6w proton whose kinetic energy is 6.35 GeV?    GeV

  Calculate the wavelength of 35 kph6uoqs3x mn.w7x85-GeV electrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cyclotron in whi/- lgr y)he6rwpyw;k3 ch 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 protu8l6g0 di*szobt0+pd a (qt) bon in the 1.0-km-rpb +t6ibt(ol z80g dqs* u0ad)adius 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-fd of,0sv4 v* e:dyp6)5y6yurb d4c cc2 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 details9 45nfn8qi rij3rb8 ax of the nucleus: 30-MeV alpha particles or 30-MeV protons? Compare eacnjfiq45in r3rx8 b a89h 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 many revo n;b0m2h;qtfpy 1mb w-lutions do protons make to reach a kinetic enh q1 f t-bypw20;bm;mnergy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelengtm0qh. z(tn 2aa)wgz8ih ($\lambda$, 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 ac- f*fn7r jeknvb4d ;j2celerate 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 teilno*a8: h8 mngv/8g2 kvi.r 8gwm37b duku-o house the magnets for the Large Hadron Collider (LHC) calls for proton bedn ukg-lmer. bi3ikv:m w288o 8h g7v u8gan/*ams of energy 7.0 TeV. What magnetic field will be required? B =    T

  The 1.0-km radius Feruamn8. 1d rks:milab Tevatron 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 .d k8u:1rsamn 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 .cki (gatimi 0fi;12e(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 needew; vj; b co/d)3mt8 e2gnulub;d at the 1.0-km-radius Fermilab synchrotron for 1.0-TeV p on3dvlc)8 /eutb; ; wmj;gu2brotons? B =    T

  How much energy is released in the(68sko0em) p0wh: mhg,6iaiahj i v)j decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy ise.zri t y+r -;drpar5c0o;3u8xq qfc1 released when a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is re-3ojbd .t l.peyf+3qeg9o1yequired to produce a neutron-antineutron pair?    MeV

  Estimate the range of the strong force if the mediating particli xde33(*pkks e were the kaon insteakx e *spid33k(d of the pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other ieeq6 d(..p izwith equal speeds. What minimum kinetic eni(q.6 ep.ziedergy must 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 travelin,l0mrtz6i.x h g at the smhli, tzx.6r0ame speed toward each 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 masses or nk)ggc0rxul4 2/5kg f the W and Z parti n0kgxu5r) 4r2k/ glcgcles as about 80 to $90\ \text{GeV}/c^2$. $mc^2$$\approx $    $\times 10^{-18}\ \text{m}$

  What are the wavelengths o(:k b*wf+g5 npn ksk7rtab+ n:f the two photons produced when a proton and antiproton a+7(pnkbn :nsf:k *kb targ+w5t 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 g/ule6 2i6d liand energy, that it is impossible for an isolated electron to radiate only a single photon. (b) With this result in mind, how can you defend the photon exchange diagram in (Fig. Beu i 6il2/ed6lglow)?

  What would be the wavelengths of the two photons produced when an electron and wzm)cc/h;v(n -)i;tx6kra z va positron, each with 420 keV o6i;zzmv txracn;) h/- ( cv)kwf 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 forbwd sx (b+md)f*.ao / wsm4fw) msago/:idden, explain what law.abw/ 4w ddo( f*)xm/:)+mo gam ssfsws 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 each of the twn8xm1vba 13 hv2,ybom:dnr7ro 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 enul/v1,oy0mt a-4kie pergy 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 width and then the lifetime ote ,/t ckinlulkn bo z;0/9k-,f the $\Delta$ resonance using the uncertainty principle.
$\Delta E$ =    MeV
$\Delta t$=    $ \times 10^{-24}\ \text{s}$

  The measured width of tpu0a.6mnsyz4 sn l:t3he $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width of thex -xzyg9n+-f bipw1 9s $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or uncera up1-zvpx2 oq948vx)a;ix ct tainty) 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 are forbidde wwnk8e.xi8)bn+qij )r 0ce6sn, explain which laws are violated. e. b w+w80x))qseknrji nic 86
(a) $\Xi^0 \to \Sigma^+ + \pi^-$
(b) $\Omega^- \to \Sigma^+ + \pi^- + \nu$
(c) $\Sigma^0 \to \Delta^0 + \gamma + \gamma$

What are the quark combi;2qn diu95xjh nations that can form (a) a neutron, (b) an antineutron, (cj2x 9du;5niqh ) a $\pi^+$, (d) a $K^-$?

What particles do the following quark combinatp ,s/v r sm45gd6ye0ecions 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 to produce a 2dx, npk8s+/6xyrlok*xa 7idsm: x lyz4wl-6 $D^+$ 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. Belus :pui3zc.q+mte+jt*v: hg76v6po) yl+ elk ow) for the reactionj7 +luivzee gv pu+ )ks.*ttlh+66 o::3my pqc $p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for theo2m,ja2t33n h cw i1zcusb;(v reaction $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a proton whose s2*qghr8m lz*g-l ew :kinetic energy is 25 GeV? What is its wave :ew8rshlg* qz-g2l m*length?
$\approx$    $ \ \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-km0g5vfrlgvj6e e9/ gmm 04q4vpn*cqt(26 szqp-radius Fermilab Tevatron with an energy of 150 GeV. If they are accelerated by 2.5 MV each 0ves0tpvfe494qnp *q 5 l6mg /g2q(zmcgjr6 v 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 releasek0u/c bxx59d:0wr1 hq1due.pdpmf-rd when an electron and a positron annihilate each otw. 1d5 -xudp m/k9 dpeubcq0rhr10fx:her? $E_{\text{total}}$=    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 e bhkqpi8+f5+qop7 d,ek 6h p.are possible, and by what interaction could they oc.+7pkphed f8q5 ie 6ob,p+hqkcur? 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 reactiv.3jgr ;*ccxfw51gendwf ,6 tons are possible, and by what interaction could they ocwxvnj ,gd;f 563.* wtef gr1cccur? For 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 a(s3ot79edf u eaf6n7v $\pi^+$ 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 bxm.sgnhm* sp .h4aa, l54cw8*dwdy+ 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 producin3(dsrto far-jt/: *ee4;t0 xi2zc ubeg a pion.xe rftt02c;doz (*u/e i 3-jetrb s:a4 $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value c6/tqj9e,r krfor 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 aomw)dp*v6r: t am nm5; water molecule?    fermions

  A proton and an antiproton annihill: x3h7 fgoxj3qxyk-*ate each other at rest and produce two pions, 7-:yxlqgx3 3* hxfkoj $\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called unification dist2n4 uw4 oiz:m:w;ols hance 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 t ye,uapt3-w 7d1mjsq- erms 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, - u3way jp7e1m,stqd- on average, ignoring any collisions? $\Delta x_{\text{lab}} = $    $ \times 10^{-5}\ \text{m}$

Identify the missing particl h+ 3rbt jyim aje29rhx:q604b)yad*h e in the following reactions.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to dvhm,h w6/xeh8 w4.rv pescribe the reaction $p + n \to \pi^+ + \pi^-$.

What fraction of the spph d rj .mc-+yyrz sq-,nc r6rg7d(-g,eed of light $c$ is the speed of a 7.0-TeV proton?