Give a reaction between two nucleons, similar to Eq. 32-4, that could p+z ;hd2ipcl9ddtu e0 78am d1froduce a z1pid 2cam08dl; f+7de d9uth$\pi^0$.

  If a proton is moving at very high speed, so that its kinetic energy r r28q zj3d-j;ytm3r4r4nmm iis much grer3ryr-itmj8m 2 nd4rzj4;q m3 ater than its rest energy ($mc^2$), can it then decay via $p \to n + \pi^+$?  ----待选择----yesno 

What would an "antiatom," made up of tj zu(t,rutv7th * z 8cg*,tw2khe antiparticles to the constituents of normal atoms, consist of? What might(w8uz* zc vth2t r gj*kt7u,t, happen if antimatter, made of such antiatoms, came in contact with our normal world of matter?

What particle in a decay signals the zbmpd 1. ,) i7nqrwf2delectromagnetic interaction?

Does the presence of a neutrino among the decay pggffd-d 93uv6) g(uvh3m zgk+roducts of a particle necessarily mean that the decay occurs via the weak interaction? Do all decays)dghkz dvfg f3 3(ug-+6u9gmv via the weak interaction produce a neutrino? Explain.

Why is it that a neutron decays via the weak interaction even though the ne -i gp6z :w;c4cx9f o).ynu yu,npm4dwutron and one of its decay products (proton) are strongly interactiyfu:9xy .gc zmwo ,n-4d uw)inc6p;p 4ng?

Which of the four interactions (strong, electromagg+gerzwk; bh5.674t agcmcz u7 /teq8netic, weak, gravitational) does an electron take part in? A neutrino? Ak+gmt.b 5wg77ea6u4 e g zqrtc z8c/h; proton?

Check that charge and baryon number arn0srpphz,j; t4 su)uuy 5 iw2)e conserved in each of the decays in Table 32-2pr;2stnuuh) )y, j w4ip 50zsu.

Which of the particle decays in Table 32-g)5 d(hhco/k6.p g8 kcuxwh9n2 occur via the electromagnetic interaction k )nc(x6 udhgoph 95g/wc.k8h?

Which of the particle decays in Table 32-2 occur by the weak interactivj/2x mg+ f0o:x bkfn6on?

By what interaction, and why, d1n 0fy mwq(i 9gf1hyrpo8xl,:k-fy l6oes $\Sigma^0$ 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 dec: 1xv;o mtz1gcays in Table 32-4 occur via the electromagnetic interac cv;ox 1gzt:m1tion?

Which of the particle decays in Table 32-4 occur by the we1drul 9e ;x2x7w bcih/ji9q0xak 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 )sw.o bdmlvu3y7v. b ycy.()um+wi35aklk b, no color charge or electrical charge, and did not feel the weak force. Could you say that this particle even exiss, l awdyv.yl3my c.m.v+kk(w5bu bi )7)3bo uts?

  Is it possible for a0g -dr(o ;b,2pq1azuuh; gu uh 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 chromodynamics, would it be possia de* g/2ypc2sble to find particles made up of two quarks and no anti2asyegdcp* 2 /quarks? What about two quarks and two antiquarks?

Why do neutrons decay when they are free but not when they are insinm zdp; dy+ -j2;(nlyy d mx72bzi-*npde the nucleus?n2mpy ydnd2ylxz ip(d;- +b*m- ; j7zn

  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 6.3bz e;*7ha. )9puq kgij5 GeV?    GeV

  Calculate the wavelength khvtg,s;lqf:20d1 b q7u2r ti/ ce,frof 35-GeV electrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cyclotro0k*5n xbt/jt4 yoh-9sne 6nhdn in which protons make $2.8 \times 10^7$ revolutions per second? $f$ =    T

  What is the time for one complete revolution for a vermk0ku t1/ti xwh6e+v. y high-energy proton in the 1.0-km-radius Fermilab mwv16kki t txu.e+ 0/haccelerator? 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/,f7qt s ,:gcf5t;fogfu cfm 2 Example 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 de-exz78zy4iyksw.-+ g cajjg+ 0mgtb 8 tails of the nucleus: 30-MeV alpha particles or 30-MeV protons? Compare each of their wavelengths with the size of a+b y jkw-8i+gtc7z48j.x0agym g-e sz nucleon in a nucleus.  ----待选择---- alpha particles protons 

  The voltage across the dees of a cyclotron is 55 kV. How di:6kxdwr ) z/di*3v tmany revolutions do protons makix6 d /di w)vzkd:r*t3e to reach a kinetic energy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelengt3r v: m )-hmonst0i-zeh ($\lambda$, 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 d,oosc k, xclx qq,8hut, zs 18o9kyww ,8nw6m8euterons ($^2\text{H}$, 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 Large Hy ze.9/e3yzo yadron Collider (LHC) calls for proton beams of energy 7.0 TeV. Whay93 ez/eoyz .yt magnetic field will be required? B =    T

  The 1.0-km radius Fermilab Tevatron takesx:-v:f egradcw 8jqd.9 2kg,b about 20 seconds to bring the energies of the storeqc8d.b:2kgaw j- ex,rd f9gv: d 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 essentially $c$ the whole time.) Energy/revolution =    MeV/rev

Show that the energy of a particle (charge+ldx) 4nr.v,ldm20ua i x ich. $e$) 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 Fermilab syn;i yor4ryvjdt5fgl . e8f:n jc7k-6s8v mw9b5chrotron for 1.0-rs9r4 moic;b7 .v:tjny 5d v5 lyw gjkf68ef8-TeV protons? B =    T

  How much energy is released injy**b9ssm7-e jk4z-uf hh6ju the decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is ,f2ib-xg 7rsw released when a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is required to produce j wg 3.ush :/c/lmt-dqi92cvfa neutron-antineutron pair?    MeV

  Estimate the range of the str keny*s kwy8 xbr9gg:,/f3 rh:ong force if the mediating particle were the kaon instead of the pion. 3 gyn* r8kkrx ,bwhsfg/y:9e: $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equal speeds. What minimum kinet,d i3wf9e ou-tic energy m,we- ou3fdit 9ust 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 ifobn 5n4 5+ksgikz 2k+u they are traveling at the same speed toward each ot+nsb oinu2k5k+gk4 5z her, 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 mas wxyq97uy7wln8nso ) (lbbi23ses of the W and Z particles aq7( )7ibyo23nlywwlxu 8bn s9s 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 ant, q52r*pq-l/gr** -a 4luaj t1fuk r-xjinpraiproton -l4rqa*ppj1 jkug2aq*u*--i r a5fnt,xl /rr 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 momn ajt1,qvaw 6)entum and energy, that it is impossible for an isolated electro,a)q1tn w6vj an to radiate 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 pro;)fr d s*effs.duced when an electron and a positron, each with 420 keV of kinetic energy, aesrf* )sfdf.; nnihilate 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?i5ee7 v e;z +mpekr oo5yf;.*k For those forbidden, explain what laws are violated. yp5.+;* o7o;fkr eie5ez v mke
(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 mf jpv3b9v),i x:v )ns;,i5z yvlij;qof 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 kineti-8c,kv t-s dkhbx,7 pgkoa*.jc 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 tb f8,x4o2, w1wraz tjphe 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 thtqplxe,4)gc b4,c1i v e $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width ozh*7+vhfe i k sew:2z ouq;i.*f the $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or un:ynyk9 m)f. .x e5nqgicertainty) 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 sjx nhe6g.zhx24ww7n.ei( z. are possible? For those that are forbidden, explain which laws arn h xwne6.szg .(x e.wjh27iz4e 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 anticd(+le1t a nda ug9+e(neutron,u+entae ac( 9(1 g+ldd (c) a $\pi^+$, (d) a $K^-$?

What particles do the following quark combinations produyh 4ynl) 8kgs 7u*,g91mphxr a wg7ui+vhl55pce: (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 producme/ )r6hz g77ub uyvs7e 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 diag 2boax7y;o(aee*)c ik ram using quarks (as in Fig. Below) for the reaction o e bi2ea )aky*(c;xo7$p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram for ti3i p*7d;8w :e naxtxr,z5labhe reaction $n + \nu_\mu \to p + \mu^-$.

  What is the total eno9 ax-al hcm-yb*,z)xergy of a proton whose kinetic energy is 25 GeV? What is its wavelengthx y aa9o)*lm,xh-zbc-?
$\approx$    $ \ \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 energy o zk4rdj3: 5rp*uk :ggi:nbte 7f 150 GeV. If they are accelerated by 2.5 MV each r:rg*d5nk:zje7 g4t : b3urip kevolution, 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 redislo: w6ot,y+q ex+4y/lu -u leased when an electron and a positron annihilate each othio-+lsdy u ly/x +wt,eu:6qo4er? $E_{\text{total}}$=    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 posse ;mz ()zueky5(*d//le vgk+u gaf r/rible, and by what interaction could they occur? For those forbiddendku //v)kl;r+ *fem/azz(5e g er(yg u, 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 possiblefa8s. nm e+qh-dle(. c, and by what interaction could they o-ah(dc qsn.l.em8ef+ ccur? 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 a;tvrph)f k qky4j9npr /a1,) $\pi^+$ 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 xk9e hde;aq g:hw; tf97oqd: +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 z(.m6e (fd(l2x zpwcmreactions, Eq. 32-4, for producing a pion. pcf(m wexz6 .ld((z2m $Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value for the 73qrrbgs, 5o ly4wjo *0vrm+zreaction $\pi^- + p \to \Lambda^0 + K^0$ 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 sz rgof)u.f8af;6c* 1f1 oeen fermions are there in a water molecule?    fermions

  A proton and an antiproton annihilyr7qdzcut;z y/d cux ae/e. /.a(w7n-j9 yi3mate each other at rest and produce two pions, / -azw;ye( tu.i y7/zumejd9.7q dryanx c3/c$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called un-zb 3cr7 xuksrc30 v8xa4nlz ;do.y* nification 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 Taiq*bew*fa d.8f 9t23zb *djyk ble 32-2 are in terms of proper time, measured in a reference frame where the partib fzfea* 3* *yj98.wib2qdtkd cle 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 average, ignoring any collisions? $\Delta x_{\text{lab}} = $    $ \times 10^{-5}\ \text{m}$

Identify the missing particle in the following reactions. z4ma4uorm v )2
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to describe the reactionfh aw7m-qqp)1eff3h2 $p + n \to \pi^+ + \pi^-$.

What fraction of the speed of lighnb5yi5su 0l 7aqn1zh *vc7b9pfh e;qx503 m elt $c$ is the speed of a 7.0-TeV proton?