Three quarks for Muster Mark! Sure he hasn't got much of a bark And sure any he has it's...

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

qq

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