Give a reaction between two nucleons, similar to q2s.z x)kxsp6 Eq. 32-4, that could produce a x6kq p )sszx2.$\pi^0$.

  If a proton is moving at very high speed, so that its kinetic e3l1+msiq + .vq0k , qc,asfczkkkt+n o v2r:u:nergy is much greater q+ukvs,z.2kv c0+t:1iqm3kc+rkq :n, lfoa s 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 the aa;0 8+d ov4lwnqq;. fambt4 yvntiparticles to the constituents of normal atoms, consist of? What might w.vaf8td+ l;nmy4bv0 aqqo4 ;happen if antimatter, made of such antiatoms, came in contact with our normal world of matter?

What particle in a decay signw8grasf .3k.tals the electromagnetic interaction?

Does the presence of a neutrino among the decay products of a particle necessaria+ylg0w ) n05/o/h y4guyc laqfud2r:ly mean that the decay oa dr gagfy2/uhyywou4ln0 ql5+ /:c0)ccurs 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 interactios36m 4pvdluu8x vft. 8n even though the neutron and one of its decay products ( muf8vp6s3vu4 td.8xlproton) are strongly interacting?

Which of the four interactions (strong, electromagnetic, weak, gravitational) dow8fwd9 1)y bh u:fu*mpy0j 94dzi6epges an wfupd1y989 *6hdwu:) figm pzb4jy0e electron take part in? A neutrino? A proton?

Check that charge and baryon number are conserva03 e+g 5x qzcim,g1ixed in each of the decays in Table 32-2.gxmq03ag+iz i5x,1 ec

Which of the particle decays in Tabqkha33 x/yive 7 2o; aajc0nz7le 32-2 occur via the electromagnetic interaca qzo3;c aehx 0v72n3yj 7kia/tion?

Which of the particle decal5 7:jhy( d-eivm(uf wys in Table 32-2 occur by the weak interaction?

By what interaction, and why, doelrxye .;3td- ww(43entxg0 tas $\Sigma^0$ 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 g3hk/m . v:uky8i jz:lsuyk,232-4 occur via the electromagnetic interactims3h8zik.l:jkukv /: y gu2y,on?

Which of the particle decays in Table 32v :6w7dic8 jk*bwpqs + 6mb7j q/e*qf6rz -azc-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" that was massless, had +md ,w8q rpos+ pllasga2a9:4no color charge or electrical charge, and did not feel the weak force. Could you say that th9 + gsr4dam8 l,sq2law:+op apis particle even exists?

  Is it possible for a parcl48rsss 3d)jticle 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 chromodynamicbs--qc bjpl) zh(-iw.s, would it be possible to find particles made up of two quarks and no antiquarks? What ab .-zcslhbj w-p)-iq( bout two quarks and two antiquarks?

Why do neutrons decay when they are free but not when they are inside the )a r1oc rln,kmyh.3 9rnucleus? rr o,ck).3l h9ryma1n

  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 gz+5cdb: ggjpe+ rr7g5/ u wmr: yqer1lr;* 6z6.35 GeV?    GeV

  Calculate the wavelength khjy 5d6 ore70of 35-GeV electrons. E =    $\times 10^{-17}\ \text{m}$

  What strength of magnetic field is used in a cyclotron in w nvb((ij;/ ; h0jmatsthich 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 pr+l vwaaj0 00ykoton in the 1.0-km- ykva a0w00j+lradius 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 32-2 accelerat6ms i/ jlt5vgeb9ni+ x9 z.hz*ed $\alpha$ 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 particles uail55ff+z6tw b hyl ;; de0*x8)vdlz or 30-MeV protons? Compare each of their wavelengths with the *lzxeluw6fh;58fb5i+;dv yzd 0)altsize 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 revolutioniz)t+vj( go u,tg0*6*yb w ,huur.ew ks do protons make to0g*kuwu u, toei,zh (6y+vgjw *).trb reach a kinetic energy of 25 MeV? $\approx $    $\ \text{revolutions}$

  What is the wavelength,0pze *vrv;j d2a;id l ($\lambda$, 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 dg/*rjdi 5n mw7euterons ($^2\text{H}$, 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 Hq3ix0x :1:cu )sythdtadron Collider (LHC) calls for proton beams of energy 7.0 TeV. What magnetic field will be requi qx u31s::)htc iyt0xdred? B =    T

  The 1.0-km radius Fermilab Tevatron takes about 20 seconds to bring the 9ze7(ziyx0afl 16moj energies of the stored protons from 150 GeV to 1.0 TeV. The a 71a6z90z (folyxmei jcceleration 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 a) .g4/ rmhyo6ev+lmr of 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 +6fvk9ckht: uat the 1.0-km-radius Fermilab synchrotron for 1.0-TeV protons? kt c+6h9vu: fkB =    T

  How much energy is releab ujumf)296sihp,w, lsed in the decay $\pi^+ \to \mu^+ + \nu_\mu$? See Table 32–2.    MeV

  About how much energy is relhi oa(8cl 1s0+nyu fn2r9bdy;eased when a $\Sigma^+$ decays to $n + \pi^+$? (See Table 32–2.)    MeV

  How much energy is requirl66t5cs7 -rv+ vnmd vped to produce a neutron-antineutron pair?    MeV

  Estimate the range of /o soqq.w9 3ttthe strong force if the mediating particle were the kaon insteao3t q 9w/stqo.d of the pion. $mc^2$ $\approx$    $ \times 10^{-16}\ \text{m}$

  Two protons are heading toward each other with equal speeds. Wham6hg 3 w8cdt7at minimum kinetic energy must eachd6 7ma 8gwhct3 have if a $\pi^0$ meson is to be created in the process? (See Table 32-2.)    MeV

  What minimum kinetic esv+v z) k 02rrg-*vzlcnergy must two neutrons each have if they are traveling at the same speed toward each other, collide, and cvzv srg*zl+v2)k0 -rproduce a $\pi^0$ pair in addition to themselves? (See Table 32-2.)    MeV

  Estimate the range of the weak fo7ty ,rqil 6:w+s, cdmurce using Eq. 32-3, given the masses of the W and Z particles as about 80 cm:ly,d67+r,stw q iuto $90\ \text{GeV}/c^2$. $mc^2$$\approx $    $\times 10^{-18}\ \text{m}$

  What are the wavelengths of thnhq::m iupr54n jvt1 7e two photons produced when a proton and antiproton at rest annihni: jh1rqmup7 tnv :54ilate? $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 moment yri mza)hef. p0in4ym,gc v-po62; +fum and 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 dia4yiy;g fp n.2)m-if+rmp 0 z,v6ca ehogram in (Fig. Below)?

  What would be the wavelengths of the twowsr(8u 4zi5di b3cp09;q/r; dyxmeoh photons produced when an electron and a positron, each with 420 h0 d4 mes cri;9(3zq5rdow/8 piyuxb;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 dec xor66rkc p f-7-mi)uhmww 2r:ays are possible? For those forbidden, explafr-m-6: rrhiw)c26 w7mupox k in what 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 each of the ix+j8u 3 1xmnv +kvvwb/t(is0two 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 in the desmkoe8*sk:lgykm3 7 4 cay $\mu^- \to e^- + \bar{\nu}_e + \nu_\mu$. [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 eneds9c:/ vt 1ofx3cakd .rgy 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 th juhwdsqp. w)1tvl*.2e $\Upsilon$ meson is 88 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  The measured width o1qy i9ce+r3q-7 ojdwcf the $J/\psi$ (3685) meson is 277 keV. Estimate its lifetime. $\Delta E$ =    $ \times 10^{-21}\ \text{s}$

  What is the energy width (or uncwhs .,g9 /yf0uq3gmepertainty) 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 ni dre0e0n e avmv* 1qu68+sci11uw)b that are forbidden, explain which lawsen*i1v16u) 1u8a0qcb wr e+en0i m dvs 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 c;*ll n+usa3ic ombinations that can form (a) a neutron, (b) an antineutron, (c) a l*ci ;+lsna 3u$\pi^+$, (d) a $K^-$?

What particles do the following quark combinations produce: (a) ylw-n)yroc:. prsd:*,c or*m$uud$, (b) $uu\bar{d}$, (c) $u\bar{s}$, (d) $\bar{d}u$, (e) $c\bar{s}$?

What is the quark combination needed to /dmworc/uy.f 2d qv,3l t2g.l 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) for the reactionj 4w1as psk4s:/lzp:je*e0p k *:spp p1eake4k 0ssj zjw4/ l: $p + \pi^- \to n + \pi^0$.

Draw a Feynman diagram0t5lt(l xm j,,i jr,dk for the reaction $n + \nu_\mu \to p + \mu^-$.

  What is the total energy of a proton whose kinetic energy is 25 GeV? Wha0yc+oh7ovzde4(p5 z:mz d-k j t is its wavev 0 oj:y4dze h mzz57co+-p(kdlength?
$\approx$    $ \ \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 injectedkc6/zoiw1pt11 r 2urc into the 1.0-km-radius Fermilab Tevatron with an energy of 150 GeV. If they are accelerated by 26u1cz2 prk/r11i ctwo.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 relf0kq*ab.8kea+d/ i tleased when an electron and a positron annihilate each oaa8f* t/0k +beklqid.ther? $E_{\text{total}}$=    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 wha - p:suyejkb 2s zc49.2/upylat interaction could they occur? For those forbidden, explain bjc-y/eulu.:9s4pz2 yp2 kaswhy.
(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 coul vme*tf37ct; cd they occur? For those forbidden,3m *c7ctv;tfe 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 b t h)0mi6tl5( mfsi8e z))sti$\pi^+$ is $\pi^+ \to \mu^+ + \nu_\mu$. What would be the equivalent decay for a $\pi^-$? Check conservation rules.

  Symmetry breaking occur5ssm *id,n; bnx4p 4cus 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. 32viaj., vdpm7hhw5)qn:bgtep.7xd2 8 u le m.7 -4, for producing a pion. e7dh.)qv,p wxtinm2ub 7: .jm hl.edavp78 5g$Q$ =   $MeV$ or $Q$ =    $MeV$

  Calculate the Q-value for cvrg ly3t-7 h2the 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 fer* 5 (hl:(izmlyiaeq6g*kt bi5mions are there in a water molecule?    fermions

  A proton and an antiproton annihilate each otrp/ s4 b9chbg0q2l3f mher at rest and produce two pions, lrbhgpsc0m9q/3f 4 b 2$\pi^-$ and $\pi^+$. What is the kinetic energy of each pion? $2m_pc^2$ =    MeV

  (a) Show that the so-called unification dista e4hh u9csae4qq .07honce 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 prin r/a g9103i0egqcvvtz8azx .,*bvdo :ni0noper 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 itvgct9 v0g bdnio/8 ria:n*niq1z0e0z.v3 ,x as 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 follofdly gl+;53y;4izgyf 9d:r tjwing reactions.
(a) $p + p \to p + n + \pi^+ + ?$
(b) $p + ? \to n + \mu^+ + \nu_\mu$

Use the quark model to6c f0z5ns/ v8c6nrubj describe the reaction $p + n \to \pi^+ + \pi^-$.

What fraction of the speed of light t)t:,av;mkcm$c$ is the speed of a 7.0-TeV proton?