Title: ParityViolation and Strange Quarks: Theoretical Perspectives
1Parity-Violation and Strange Quarks Theoretical
Perspectives
M.J. Ramsey-Musolf
Hall A Collaboration Meeting December 05
2Outline
- Historical Context
- Strange quarks what have we learned?
- Other aspects of parity-violation and QCD
radiative corr, N to D , gg
3PV Past, Present, Future
4PV Past, Present, Future
5PV Past, Present, Future
6Quarks, Gluons, the Light Elements
Lattice QCD
7Strange Quarks in the NucleonWhat have we
learned?
Jaffe 89 Hammer, Meissner, Drechsel 95
- Dispersion Relations
- Narrow Resonances
- High Q2 ansatz
8Strange Quarks in the NucleonWhat have we
learned?
HAPPEX SAMPLE MAINZ G0
K. Aniol et al, nucl-ex/0506011
9Strange Quarks in the Nucleon What have we
learned?
- Strange quarks dont appear in the conventional
Quark Model picture of the nucleon
- Perturbation theory is limited
?QCD / ms 1 No HQET
mK / ?c 1/2 ?PT ?
J?s J?B - 2 J?EM, I0
10What ?PT can (cannot) say
Ito R-M Hemmert, Meissner, Kubis Hammer, Zhu,
Puglia, R-M
The SU(3) chiral expansion for mB
11What ?PT can (cannot) say
Ito R-M Hemmert, Meissner, Kubis Hammer, Zhu,
Puglia, R-M
The SU(3) chiral expansion for mB
O (p3) non-analytic in mq unique to
loops leading SU(3)
12What ?PT can (cannot) say
Ito R-M Hemmert, Meissner, Kubis Hammer, Zhu,
Puglia, R-M
The SU(3) chiral expansion for mB
O (p4) non-analytic in mq (logs)
13What ?PT can (cannot) say
Ito R-M Hemmert, Meissner, Kubis Hammer, Zhu,
Puglia, R-M
The SU(3) chiral expansion for mB
O (p4)
SU(3) Sym breaking
Two-deriv operators
1/mN terms
14What ?PT can (cannot) say
Ito R-M Hemmert, Meissner, Kubis Hammer, Zhu,
Puglia, R-M
The SU(3) chiral expansion for mB
- converges as (mK / Lc )n
- good description of SU(3) SB
15What ?PT can (cannot) say
Ito R-M Hemmert, Meissner, Kubis Hammer, Zhu,
Puglia, R-M
O (p4) octet only
Implications for ms
O (p2) singlet
O (p3,p4) loop only
O (p2,p4) octet
O (p4) singlet
- Near cancellation of O (p2,p4) octet loop
terms - Expt b0 0.6 b8 terms slightly gt 0
- Models different assumptions for b0 0.6 b8
terms
16Q2 -dependenceof GsM
17What ?PT can (cannot) say
18What ?PT can (cannot) say
19What ?PT can (cannot) say
Ito R-M Hemmert, Meissner, Kubis Hammer, Zhu,
Puglia, R-M
O (p3) non-analytic in mq (loops) mq
-independent cts
The SU(3) chiral expansion for rs
20What ?PT can (cannot) say
Ito R-M Hemmert, Meissner, Kubis Hammer, Zhu,
Puglia, R-M
The SU(3) chiral expansion for rs
21Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
22Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Kaon cloud
Not sufficient to explain GsE,M
23Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Kaon cloud models
Not reliable guide to sign or magnitude of GsE,M
24Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Chiral models
Implicit assumptions about b0 , c0 , b0r ,
25Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Disconnected Insertions
Still a challenge
26Dispersion theory
Jaffe Hammer,
Drechsel, R-M
27Dispersion theory
Jaffe Hammer,
Drechsel, R-M
28Dispersion theory
Jaffe Hammer,
Drechsel, R-M
29Dispersion theory
Hammer R-M
30Dispersion theory
Hammer R-M
31Dispersion theory
Hammer R-M
- Kaon cloud not dominant
- Not sufficient data to include other states
32Lattice Computations
See also Leinweber et al
Dong, Liu, Williams (1998)
Lewis, Wilcox, Woloshyn (2003)
- Quenched QCD
- Wilson fermions
- 2000 gauge configurations
- 60-noise estimate/config
- Quenched QCD
- Wilson fermions
- 100 gauge configurations
- 300-noise estimate/config
33Lattice Computations
Leinweber et al
34Lattice Computations
Leinweber et al
35Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Disconnected Insertions
Still a challenge
36Combining ?PT, dispersion theory, lattice QCD
SAMPLE
37Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Chiral models
Implicit assumptions about b0 , c0 , b0r ,
38Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Jido Weise
No
Implicit assumptions about b0 , c0 , b0r ,
39Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Jido Weise
Implicit assumptions about b0 , c0 , b0r ,
40Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Zou Riska (QM)
Give wrong sign ???
Implicit assumptions about b0 , c0 , b0r ,
41Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Zou Riska (QM)
Give right sign ???
Implicit assumptions about b0 , c0 , b0r ,
42Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Zou Riska (QM)
t-channel resonances?
Implicit assumptions about b0 , c0 , b0r ,
43Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Chiral Quark Soliton
Implicit kaon cloud b3-7
resonances ?
Implicit assumptions about b0 , c0 , b0r ,
44Strange Quarks in the Nucleon What have we
learned?
Its all in the low energy constants
Chiral Quark Soliton
Implicit kaon cloud b3-7
resonances ?
Implicit assumptions about b0 , c0 , b0r ,
45Strange Quarks in the Nucleon What have we
learned?
New puzzles higher Q2-dependence
46Radiative Corrections the Hadronic Weak
Interaction
- GAe
- N !D
- PV p photo- and electro-production (threshold)
- Vector analyzing power (gg)
47at Q20.1 (GeV/c)2
- s-quarks contribute less than 5 (1s) to the
protons magnetic form factor. - protons axial structure is complicated!
R. Hasty et al., Science 290, 2117 (2000).
48Axial Radiative Corrections
49Anapole Effects
Hadronic PV
Cant account for a large reduction in GeA
50Nuclear PV Effects
PV NN interaction
Carlson, Paris, Schiavilla Liu,
Prezeau, Ramsey-Musolf
51SAMPLE Results
R. Hasty et al., Science 290, 2117 (2000).
at Q20.1 (GeV/c)2
- s-quarks contribute less than 5 (1s) to the
protons magnetic moment.
200 MeV update 2003 Improved EM radiative
corr. Improved acceptance model Correction for p
background
125 MeV no p background similar sensitivity to
GAe(T1)
E. Beise, U Maryland
52Transition Axial Form Factor
Off Diagonal Goldberger-Treiman Relation
53Measuring GAND(Q2)
54Weak interactions of s-quarks are puzzling
Hyperon weak decays
55Weak interactions of s-quarks are puzzling
56Weak interactions of s-quarks are puzzling
Resonance saturation
Holstein Borasoy
S11 Roper
57Weak interactions of s-quarks are puzzling
Resonance saturation
Holstein Borasoy
S11 Roper
58Weak interactions of s-quarks are puzzling
59We have a DS0 probe
Use PV to filter out EM transition
Zhu, Maekawa, Holstein, MR-M
60We have a DS0 probe
Naïve dimensional analysis (NDA)
Resonance saturation
61Measuring dD
62N!D Transition
63Radiative Corrections the Hadronic Weak
Interaction
- GAe
- N !D
- PV p photo- and electro-production (threshold)
- Vector analyzing power (gg)
64Vector Analyzing Power
- T-odd, P-even correlation
- Doubly virtual compton scattering (VVCS) new
probe of nucleon structure - Implications for radiative corrections in
other processes GEp/GMp, b-decay - SAMPLE, Mainz, JLab experiments
65Vector Analyzing Power
Vg VVCS Re Mg(MggboxMggcross) Rosenbluth Im
MgMggbox VAP
VW,Z Electroweak VVCS Re MV(MVgboxMVgcross) b-
decay, RA, Im MVMVgbox b-decay
T-violation
66Vector Analyzing Power
67Vector Analyzing Power
68Conclusions
- Measurements of neutral weak form factors have
challenged QCD theory - PV program has stimulated a variety of other
developments at the interface of QCD and weak
interactions - Powerful new probes of SM beyond Qwe,p , DIS
- Kaon cloud is resonant, but not dominant
- Loop calculations are unreliable guide
- Symmetry limited by presence of unknown
constants - Models remain interesting, but ad hoc (implicit
LECs) - Lattice challenged to obtain disconn insertions
- Axial radiative corrections consistent with
experiment - Axial N to D new QCD testing ground GAND , dD
- Electroweak box graphs new insights from gg ?