Locality,Lorentz inv.gauge inv. spinor vector A interaction reprensatationperturbation S-matrix...

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Transcript of Locality,Lorentz inv.gauge inv. spinor vector A interaction reprensatationperturbation S-matrix...

locality, Lorentz inv.

4/FF

gauge inv.spinor

i iiii mAgi )(totL 2/)( 2

A

vector A

2/ AA

i iii mi )(0L i iii Ag IL

0

4I!

1

n

nxdiT

nS L

interaction reprensatation

nfffT 21

)( jiji ffTff

)(

2221121 knljijill fffffffN

perturbationI0tot LLL

S-matrixprovability2

inout SP

Wick's theorem

0))()((0 yxT imk

ei

kd yxik

22

)(

4

4

)2(

0))()((0 yxT

)(

224

4 )(

)2(yxike

imkmk

ikd

0))()((0 yAxAT

ik

e

ikd yxik

2

)(

4

4 )(

)2(

0

4I!

1

n

nxdiT

nS L

2

inout SP i iii Ag IL

i iii Ag IL

0

4I!

1

n

nxdiT

nS LS-matrixprovability

2

inout SP

provability P?eqeq k

pk'

p'

0

4I!

1

n

nxdiT

nS L

2

inout SP

electron quark scattering

pk'p'k S

0)(q p†rb)(e k†sb

0

4

!

1

n

n

I xdiTn

L0 )'('q prb )'('e ksb

i iii Ag IL

provability amplitude (p'≠p,k'≠k)

Let us consider electron quark scattering.

We want to know the provability.

For this purpose, we calculate the provability amplitude.

provability amplitude

eqeq k

pk'

p'

electron quark scattering

pk'p'k S

provability P?

0

4I!

1

n

nxdiT

nS L

2

inout SP i iii Ag IL

†qb†

eb xdi I4L 2 4

2

1 xdiT IL=

0)(q p†rb)(e k†sb0 )'('q prb )'('e ksb

0

4

!

1

n

n

I xdiTn

Lbq

†be† 〉

0

1

p'≠p,k'≠k

)(2)2( 3

3ipxs

isipxss

ii evdeubE

dpp

p

p †

)*(2)2( 3

3ipxrripxrr eaea

Epd

A†

ppp

〈 bq'be' be†bq

† 〉rap 0

0

pk'p'k Sbq'

be'

=abbreviations 〈 bq'be' be†bq

† 〉†rap 0

0'qb 'eb

'' eq bb iT 2

1 2 4xd ††

qebb i iii Ag 2

4 xd ††qebbqqqeee

AgAg xdAigxdAig 4qqq

4eee

e g i ee A xd 4

q g i qq A xd 4

∴∴

provability amplitude

eqeq k

pk'

p'

electron quark scattering

pk'p'k S

provability P? 'qb 'eb †qb†

eb xdi I4L 2 4

2

1 xdiT IL1

expand square

0

4I!

1

n

nxdiT

nS L

2

inout SP i iii Ag IL

0)(q p†rb)(e k†sb0 )'('q prb )'('e ksb

0

4

!

1

n

n

I xdiTn

L

'' eq bb iT 2

1 2 4xd ††

qebb 2 4 xd ††

qebbqqqeee

AgAg xdAigxdAig 4

qqq4

eee

Tbb2

1'' eq ††

qebb2

q(x ') A (x ')

xd 4 '4xd Tbb '' eq )( eee Ag )'''( qqq

Ag ††qebbi i

xdAig 4eee

xdAig 4qqq

xdAig 4eee

xdAig 4q

qq

2 22

00

''

'' be†bq

† 〉

〈 b'qb'e

' '' ' 4qqq xdAig

xdAig 4eee

abbreviations

pk'p'k S

p'≠p ∴ k'≠k ∴

=

eqeq k

pk'

p'

electron quark scatteringprovability P?

0)(q p†rb)(e k†sb0 )'('q prb )'('e ksb

0

4

!

1

n

n

I xdiTn

L

'' eq bb iT 2

1 ††qebb i iii Ag

2 4 xd ††

qebbqqqeee

AgAg

Tbb2

1'' eq 2

xd 4 '4xd Tbb '' eq )( eee Ag )'''( qqq

Ag ††qebbi i

††qebb

xdAigxdAig 4qqq

4eee

xdAig 4eee

' '' ' 4qqq xdAig

nfffT 21

)( jiji ffTff

)(

2221121 knljijill fffffffN

Wick's theorem

pk'p'k S )(

2)2( 3

3ipxssipxss evdeub

Ed

ppp

p †

srrs Ebb )(2)2(},{ 3 qppqp †

srrs Edd )(2)2(},{ 3 qppqp †

b ipxseu

d ipxsev

†b ipxseu

†d ipxsev

pk'p'k S

'AA )'( AAT

iqe

iqd xxiq

2

)'(

4

4

)2(

) (A 'A 'eb e eg e †eb 'qb 'q ) ( qg 'q †

qb xid 4 '4xid

provability amplitude

provability amplitude

eqeq k

pk'

p'

electron quark scatteringprovability P?

0)(q p†rb)(e k†sb0 )'('q prb )'('e ksb

0

4

!

1

n

n

I xdiTn

L

'' eq bb iT 2

1 ††qebb i iii Ag

2 4 xd ††

qebbqqqeee

AgAg

Tbb2

1'' eq 2

xd 4 '4xd Tbb '' eq )( eee Ag )'''( qqq

Ag ††qebbi i

††qebb

xdAigxdAig 4qqq

4eee

xdAig 4eee

' '' ' 4qqq xdAig

pk'p'k S

) (A 'A xid 4 '4xid 'eb e eg e †eb 'qb 'q ) ( qg 'q †

qb

pk'p'k S )(

2)2( 3

3ipxssipxss evdeub

Ed

ppp

p †

srrs Ebb )(2)2(},{ 3 qppqp †

srrs Edd )(2)2(},{ 3 qppqp †

b ipxseu

d ipxsev

†b ipxseu

†d ipxsev

'44 xidxid

iqe

iqd xxiq

2

)'(

4

4

)2(xikeu '

e ' )( e g ikxeu e

''q ' xipeu )( q g '

qipxeu

'AA )'( AAT

iqe

iqd xxiq

2

)'(

4

4

)2(

pk'p'k S

pk'p'k S '44 xidxid

iqe

iqd xxiq

2

)'(

4

4

)2(xikeu '

e ' )( e g ikxeu e

''q ' xipeu )( q g '

qipxeu

provability amplitude

'44 xidxid

iqe

iqd xxiq

2

)'(

4

4

)2(xikeu '

e ' )( e g ikxeu e

''q ' xipeu )( q g '

qipxeu

xikeu 'e ' )( e g ikxeu

e''

q ' xipeu )( q g 'q

ipxeu

'44 xidxid

iqe

iqd xxiq

2

)'(

4

4

)2(pk'p'k S

4

4

)2( iqd

iq

2'eu )( e g eu 'qu )( q g qu

inout)4(4

inoutinout )''()2( TpkpkiS

i

2) ('eu )( e g eu 'qu )( q g qu

T : T-matrixpk'p'k T

()2( )4(4i kk ' )' pp

1

kk '

xid 4 iqxe xike ' ikxe ''xipe 'ipxe '4xid 'iqxe xkkqi )'( ')'( xppqi

4

4

)2( iqd

) ()2( )4(4i

iq

2'eu )( e g eu 'qu )( q g qu

kkq '

)(2 XdqeiqX 2 ) ()2(

)4(4i 2 ppq 'k' k

k' k

qq q

q

kk'q

pk'p'k T

eg

qg

eu'eu

qu'qu

ikk

2)'(

Feynman rules

kk '

i

2) ('eu )( e g eu 'qu )( q g qu

kk '

inout)4(4

inoutinout )''()2( TpkpkiS

T : T-matrixpk'p'k T

i

2) ('eu )( e g eu 'qu )( q g qu

iq

2

内線 

photon

q p

fermion

imp 1

vertex

ig

外線 incomingoutgoing粒子

反粒子

u u

v v

4

4

2 )( ipd

1loop fermion loop T matrix 1

internal line

external line

particle

ant-particle

''

' )'( rp

sp vgu s

krk ugv )('

g'g

sku

'spu

rkv '

''

rpv

ikk

2)'(

'' ffff

ffff

†')(

1)(''

sk

sk ug

imqkgu

ff

†')(

'

1)(''

sk

sk ug

imqkgu

iqg

imqkg

iqd

24

4

)(1

)()2(

loop diagram

imkg

imqkg

ikd

1)(

1)(Tr

)2( 4

4

impqkg

iqiqd

1

)()2( 24

4

loop diagram

)(1

)(

gimqk

g

ikk

2)'(sk

sk ugu )('' r

prp ugu )'(''

g

'g

sku'

'sku

rpu

''

rpu

ikk

2)'(

Feynman rules  '' ffff

T

ikk

2)'(sk

sk ugu )('' r

prp ugu )'('' T

ikk

2)'(sk

sk ugu )('' r

prp ugu )'('' T

ikk

2)'(sk

sk ugu )('' r

prp ugu )'('' T

])'(/[))((' 2''

'' kkuuuugg r

prp

sk

sk

00 †

*'' )( s

ksk uu

*0

'' )( s

ksk uu †

''0

sk

sk uu

††

''0

sk

sk uu †

''

sk

sk uu

*''

'' )( s

ksk

sk

sk uuuu '

'''

sk

sk

sk

sk uuuu

0''

'' †s

ksk uu

0†s

ksk uu

)*( ''

''

rp

rp

rp

rp uuuu '

'''

rp

rp

rp

rp uuuu

*T ])'(/[*)(*)(' 2''

'' kkuuuugg r

prp

sk

sk

*''

'' )( s

ksk

sk

sk uuuu '

'''

sk

sk

sk

sk uuuu

)*( ''

''

rp

rp

rp

rp uuuu '

'''

rp

rp

rp

rp uuuu

'

''

''ss

sk

sk

sk

sk uuuu

'

*''

'' )(

ss

sk

sk

sk

sk uuuu

'

''

''ss

sk

sk

sk

sk uuuu

Trs'

''

'' s

sk

sk

sk

sk uuuu

'

''

''Tr

ss

sk

sk

sk

sk uuuu

mpuus

ss mpvv

s

ss

'Tr mkmk

41Tr 0Tr

4Tr 0Tr

Tr

(4

'Tr 2 mkk

)

])'(''[4 kkkkkk

24m*)(

'

''

''rr

rp

rp

rp

rp uuuu

])'(''[4 pppppp

2'4m

'

*''

'' )(

ss

sk

sk

sk

sk uuuu

])'(''[4 kkkkkk

24m*)(

'

''

''rr

rp

rp

rp

rp uuuu

])'(''[4 pppppp

2'4m

'

*''

'' )(

ss

sk

sk

sk

sk uuuu

])'(''[4 2 mkkkkkk

]')'(''[4 2 mpppppp

*)('

''

''rr

rp

rp

rp

rp uuuu '

*''

'' )(

ss

sk

sk

sk

sk uuuu

])'(''[4 2 mkkkkkk

]')'(''[4 2 mpppppp )'()')('()')('())(''[(16 2 ppmppkkkppkkppk

)'()')('())(''()')('( 2 ppmppkkkppkkppk )'(4)')('(4)')('()')('( 2 ppmkkppkkppkkpp

]'4)'('4)'(')'(' 22222 mmkkmkkmkkm )')('(2))(''(2[16 kppkkppk

]'4)'('2)'(2 2222 mmkkmppm

*)('

''

''rr

rp

rp

rp

rp uuuu '

*''

'' )(

ss

sk

sk

sk

sk uuuu

)')('(2))(''(2[16 kppkkppk ]'4)'('2)'(2 2222 mmkkmppm

*)('

''

''rr

rp

rp

rp

rp uuuu '

*''

'' )(

ss

sk

sk

sk

sk uuuu

)')('(2))(''(2[16 kppkkppk

]'4)'('2)'(2 2222 mmkkmppm

)')('(2))(''(2[16 kppkkppk

]'4)'('2)'(2 2222 mmkkmppm

2/)'(2/)'[(16 222222 mmumms ]'4)2(')'2( 222222 mmmtmmtm

2222222 )'()')((2/)[(16 mmmmusus ]'8)'( 2222 mmmmt

]'8)'(2/)[(16 2222222 mmmmus

)'12'22(8 224422 mmmmus

2

'' Trrss 2

22442222 '12'22'8

tmmmmus

gg

*)('

''

''rr

rp

rp

rp

rp uuuu '

*''

'' )(

ss

sk

sk

sk

sk uuuu

scattering cross section target cross section

A area

N2 # of targetsN1 # of projectiles

Ns # of scatterings

ANNN/

/

1

2s

P 2s / NNP

AN /1

scattering provability

flux

reaction a1+a2→ a3+a4

VEdE

EN

23

2

32222

22

)0()2(2

x

pp

22iii mE pmomentumipmassim energy

volume of space:V

ANNN /21s

2

21434

34

3

33

33

s 2)2(2)2(pppp

ppS

Ed

Ed

N

TEAN ||2/ 1211 vv

VTEE

SE

dE

d

||22

2)2(2)2(

1221

2

21434

34

3

33

33

vv

pppppp

total time:T

VTEE

SE

dE

d

||22

2)2(2)2(

1221

2

21434

34

3

33

33

vv

pppppp

VTEE

SE

dE

d

||22

2)2(2)2(

1221

2

21434

34

3

33

33

vv

pppppp

VTEE

SE

dE

d

||22

2)2(2)2(

1221

2

21434

34

3

33

33

vv

pppppp

2143 pppp S 21432144

43 })()2(1{ pppp Tppppi

2

21431221

432144

43

43

33

33

||22

)()2(

2)2(2)2(pppp

vvpp

TEE

ppppE

dE

d

)(22)2(||22

)2(4321

2

214343

63

3

1221

4

EEEETEE

dEE

pppp

pvv

243

221 )()( pppps

242

231 )()( ppppt

232

241 )()( ppppu

24

23

22

21 uts

),0,0,(1 LL pEp )0,0,0,(2 Mp

)cos,0,sin,( 3333 ppEp )cos,0,sin,( 4444 ppEp

),0,0,( 11 pEp ),0,0,( 22 pEp

)cos',0,sin',( 33 ppEp

)cos',0,sin',( 44 ppEp

invariant variables 不変変数

center-of-mass frame 重心系laboratory frame 実験室系

time1a

2a

3a4a

s

t

s-channel

t-channels-channelt-channelu-channel

reaction 反応4321 aaaa

4231 aaaa 2341 aaaa

sEE 21 sEE

22

21

21

ss

E2

22

21

1

s

sE

2

21

22

2

ss

E2

24

23

3

s

sE

2

23

24

4

sss

p4

))()()(( 221

2212

sss

p4

))()()(('

243

2432

'4

))(()2(cos

24

23

22

21

22

spptss ii

'2cos

ppdt

d

1

22

21lab

1 2

s

E

21

221

2212ab

4

))()()(()(

ss

pl

center-of-mass frame

laboratory frame

)(22)2(||22

)2(4321

2

214343

63

3

1221

4

EEEETEE

dEE

ppppp

vv

)(22

''

)2(4

14321

2

214343

2

2EEEET

EEddpp

ps

pppp

)()'/)((22

)('

)2(4

14321

2

2143432143

43212

2EEEET

dpEEEEdEEdEEEEdp

ps

pppp

2

21434343

2

2 ))/'/'(22

'

)2(4

1pppp T

EpEpEEdp

ps

2

2143

2

2 '4

cos2'

)2(4

1pppp T

psdp

ps

2

2143cos32

'pppp Td

spp

2

2143264

1pppp Tdt

sp

2

434

34

3

33

33

2)2(2)2(ppp

ppS

Ed

Ed

EV2

T

2

434

34

3

33

33

2)2(2)2(2

1ppp

ppS

Ed

Ed

EVT

)()()(

)(43

42

434

34

3

33

334

22222

2pppT

Ed

Ed

E

ppppp

)()(

)(43

2

4343

63

34

2222

2EEET

EEd

E

pppp

decay width =decay provability/total time

= # of decays/ # of particles /total time

# of decays

# of particles

total time

2

434

34

3

33

33

2)2(2)2(2

1ppp

ppS

Ed

Ed

EVT

)()()(

)(43

42

434

34

3

33

334

22222

2pppT

Ed

Ed

E

ppppp

)()(

)(43

2

4343

63

34

2222

2EEET

EEd

E

pppp

)(22)2(2

)2(43

2

4343

63

34

EEMTEE

dM

ppp

p )(22)2(2

)2(43

2

4343

63

34

EEMTEE

dM

ppp

p

)(22)2(2

)2(43

2

4343

63

34

EEMTEE

dM

ppp

p

)(''

)( 43

2

4343

2

2 2222

1EEMT

EEddpp

M

ppp

)()'/)((

)(')( 43

2

434343

432

2 2222

1EEMT

dpEEMdEEdEEMdp

M

ppp

2

434343

2

2 2222

1ppp T

EpEpEEdp

M

))/'/'('

)(

2

43

2

2 4

2

22

1ppp T

Mpdp

M '

cos')(

2

432cos

16

'ppp Td

Mp

2

4328ppp T

Mp

'

center-of-mass frame

'' ffff k

pk'

p'

fermion fermion scattering

ikk

2)'(sk

sk ugu )('' r

prp ugu )'(''

g

'g

sku'

'sku

rpu

''

rpu

ikk

2)'(

T

2

'' Trrss 2

22442222 '12'22'8

tmmmmus

gg

2

'' Trrss 2

22442222 '12'22'8

tmmmmus

gg

2

'' Trrss 2

22442222 '12'22'8

tmmmmus

gg

2

'' Trrss 2

22442222 '12'22'8

tmmmmus

gg

tsmmu 22 '22

)cos1(2 2 kts

mmsmms4

))'()()'(( 222 k

''

2

2 4

1

64

1rrss

Tdtsk

''

2

4

1cos

32

1rrss

Tds

''

2

2 4

1

64

1rrss

Tsdt

dk

''

2

4

1

32

1

cos rrssT

sdd

cos2 2ddt k

散乱断面積scattering cross section

微分断面積differential scattering cross section

2

264

1Tdt

sp

2cos

32

'Td

spp

2

264

1T

spdtd

2

32

'

cosT

spp

dd

differential scattering cross section 微分散乱断面積

scattering cross section 散乱断面積

''

2

212

1

64

1rrss

Tnn

dtsp

''

2

21

1cos

32

1rrss

Tnn

ds

2

12 ii

jn

ni :# of sipn states of particle ai

unpolarized scattering cross section 非偏極散乱断面積

2143 pppp TT

ji :spin quantum #(massive particle)

(massless particle)