three quarks for muster mark! sure he hasn't got much of a bark and sure any he has it's...
TRANSCRIPT
Three quarks for Muster Mark!
Sure he hasn't got much of a bark And sure any he has it's all beside the mark. But O, Wreneagle Almighty, wouldn't un be a sky of a lark To see that old buzzard whooping about for uns shirt in the dark And he hunting round for uns speckled trousers around by Palmerstown Park? Hohohoho, moulty Mark!
es
ed
eu
31:
31:
32:
66
isospind
u
n
p
symmetrySU
s
d
u
)3(
quantum numbers of quarks
)( ud)( du
)( us)( ds
)( su )( sd
)( uu
)( dd)( ss
14
o
16
oK K
Ko
K
MeV892
MeV892
MeV783 MeV1020
MeV775
gGell-Mann - Okubo mass formula
s
s
s
...)( brgbgr uuuuuu
quark modelquark model
triangle diagram - good agreement with experiment
steinberger0
factor 9 too small in decay rate
0
Elektromagnetic pion decay:
color quantum number =>factor 3 in amplitude, factor 9 in rate - very good agreement betweentheory and experiment.
0 q
Electron – positron- annihilation
3/2)3/1()3/1()3/2( 222 R
quark model:
b-flavored hadronscharmed hadrons
R
quarks with color:
23/23
))3/1()3/1()3/2((3 222
R
35
deep inelastic scatteringdeep inelastic scattering
electron
proton
variables:
Q2 = 4 E E’ sin2/2
x = Q2 /2Mp(E’– E)
E
E’
photon
38
scaling behaviour of cross section
2)(),(
2
222
2
qFxFqW
probability that a quark carries probability that a quark carries fractionfraction of parent protonof parent proton’’s s momentum ismomentum is qq(() ) ((0< 0< < 1< 1), then), then
...)(9
1)(
9
4)(2 xdxxuxxF
45
current commutators near the light cone are
abstracted from the
free quark model
explains scaling behaviour of cross sections
SU(3) x SU(2)
u,d,s spin
SU(6)
)
222(
)(
duuuuduud
uduududuu
uudududuu
p
J
2
1
3
2)0444(
18
1
2
1 pp u
6
1)2/63)2/1(4(
18
1
2
1 pp d
3/2)2/1(
6/1)2/1(
nn
nn
d
u
qq q
qq m
eeqp
2
1)()()(
qdu
q m
e
m
ep
22
1
3
1
2
1
3
2)(
Np 79.2)(
MeVmq ...336
qq m
e
m
en
23
2
3
2
3
1)
6
1(
3
2)(
50.12/3)(/)( np
ss m
e
m
e
2)3/1()2/1()3/1()(
s
du
m
mp ,)3/1()(/)(
u, d, s,: light quarks
Electron=positron annihilation: production of the J/psi resonance
/J
ccJ /
sd
cu
4 quarks
D(+): 1870 MeV
D(0): 1865 MeV
D(s): 1968 MeV
Weak decays: c s,d
cs
cu
cd
charmed baryons MeVudcc 2286
MeVddc
MeVudc
MeVuuc
c
c
c
2454
2453
2454
0
MeVssc
MeVdsc
MeVusc
c
c
c
2695
2471
2468
0
b-quark:
1977 FNAL
bbY 3
1)( bQ
FNAL
Weak decays: c s,d
MeVsbB
MeVdbB
MeVubB
s 5366
5280
5279
0
B-mesons
b-flavored baryons MeVudbb 5620
MeVssb
MeVqqb
MeVqqc
duq
b
b
b
6070
5790
5620
/:
6 quarks?
b
t
s
c
d
u
b
t
s
c
d
u