# Presentation: 039420

## THE STRANGENESS MAGNETIC MOMENT AND THE ss- COMPONENT OF THE PROTON

- 		SAMPLE, HAPPEX, A4, G0 (2005):
- 				s > 0

## γ, Z0

- γ, Z0

## E. J. Beise et al, 

- E. J. Beise et al,
- Prog. Part. Phys. 54, 289 (2005)

- PV ASYMMETRY

## D. Armstrong & K.Carter, CERN Courier 45, 8 (2005)

## BUT μs = GMs(0)  SHOULD BE NEGATIVE !

- ASYMMETRIC LONG RANGE FLUCTUATION
- 			   ... PSEUDOSCALAR MESON LOOP

- P↑

- +e

- -e/3 (strange quark)

- K+

- Λ, Σ0,↓

- < K+ ******0** |T| p> ~ <|**** . q| >

- POSITIVE MAGNETIC MOMENT CONTRIBUTION ?

- NO ... MULTIPLY BY – 3    (< s- |γμ| s>)

- NEGATIVE GMs !

## D.Beck and

- R.D.McKeown,
- Ann Rev Nucl
- Part Sci
- 51, 189 (2001)

## IF POSITIVE GMs

- VECTOR MESON LOOPS:

- K*

- K*

- 0

- Charge coupling:  0 spin non flip,
- 	POSITIVE !

- Current coupling: **** : spin-flip
- 	NEGATIVE

- K*

- K

- ,0

- POSITIVE !

- P. Geiger & N. Isgur
- PRD 55, 299 (1997)

- K,K* loops in the ”chiral” quark model
- μs	= - 0.046 nm
- 			L. Hannelius & DOR, PRC 62, 045204 (2000)
- QCD Lattice calculation with chiral extrapolation
- μs	= - 0.046 ± 0.019 nm
- 			D.B.Leinweber & al, PRL 94, 212001 (2005)
- 			” tremendous challenge for future experiments”

##         D. Leinweber et al, PRL 94, 212001 (2005)

-         D. Leinweber et al, PRL 94, 212001 (2005)

## S- in P-state

- S- in P-state

- S- in S-state

## SPIN DEPENDENT HYPERFINE INTERACTIONLOWERS ANTISYMMETRIC SPIN STATES

- <S=0 | ******1.********2** |S=0> = -3
- <S=1 | ******1.********2** |S=1> =+1
- COLOR MAGNETIC HF INTERACTION:
- 		V= (2 / 9 m2) s ******1**** . ********2**  (r)
- FLAVOR-SPIN INTERACTION
- 		V = C ij  ******F****i.********F****j  ********i**** . ********j**  ,      C ~ 30 MeV
- NUCLEON:	<N|  ******i.********j**|N> = -2
- 			<|  ******i.********j**** ********i.**** ********j**|N> = +10

## ω ~ 160 MeV

- ω ~ 160 MeV

## ~ 200 MeV

- ~ 360 MeV

## The 

- The

- is in the S-state,
- Not KΛ like!

- B.S.Zou & DOR, PRL 95, 072001 (2005)

## General expressionsŝ in P-state

- [31]FS [F]F [22]S:	 μs = - (1/3) (mp/ms) Psŝ
- [31]FS [F]F [31]S:	 μs = - (7/6 – 1/2σ) (mp/ms) Psŝ
- [31]FS [31]F [4]S:	 μs = +  7/6 (mp/ms) Psŝ
- σ average spin z-component for S=1 uuds state
- 			(σ < 1)

## General expressionsŝ in S-state

- [FS]FS[F]F[22]S : μs =  - (1/3 + 2/3 l) (mp/ms) Psŝ
- [FS]FS[F]F[31]S : μs = + (mp/ms) Psŝ ,       J=0
- [FS]FS[F]F[31]S : μs =  - (1/3)(1 + l + σ ) (mp/ms) Psŝ ,
- 						        J=1
- [FS]FS[F]F[4]S :   μs =  - (5/6 – 1/3 l) (mp/ms) Psŝ
- 			l average mz in L=1 state
- 			( l < 1⁄2 )

## POSITIVE

- ~ 200 MeV

- ~ 360 MeV

- Positive
- exception

- NEGATIVE

- J=0
- negative

## Θ+   quark cluster models

- Jaffe-Wilczek: two scalar diquarks [ud], [us] in relative P-state & ŝ in S-state:
- 		μs = 1/3 (mp /ms) (1 + 2 ms/(mud+mus)) Psŝ > 0
- Shuryak-Zahed: scalar + tensor diquark (*l*=1) & ŝ
- 		μs = 1⁄2 (mp /ms) (1 +  ms/3mus) Psŝ > 0
- Karliner-Lipkin: scalar [ud] + [udŝ] triquark in L=1 state:
- 		μs = -1/3 (mp /ms)  Psŝ      <  0

## Summary

- The strangeness magnetic moment is most likely positive SAMPLE, A4, HAPPEX, G0
- The 4 experiments indicate that the sŝ component in the proton has the uuds in the P state and the ŝ in the ground state