PVDIS: 12 GeV at JLabPVDIS: 12 GeV at JLab
For the SOLID Collaboration
June 23, 2009 PVDIS at 12 GeV 1
OUTLINEOUTLINE• PVDISPVDIS• Physics Potential
El t k li– Electroweak couplings– CSV– Higher Twist
• Apparatus• Conclusions
June 23, 2009 PVDIS at 12 GeV 2
First Electron Parity ExperimentFirst Electron Parity Experiment
It was realized independently in the mid 70s at SLAC:It was realized independently in the mid 70s at SLACAPV in Deep Inelastic Scattering off liquid Deuterium: Q2 ~ 1 (GeV)2
10−4 ⋅ Q2APV ~ (GeV2)
This experiment convinced the world that the Z-boson violated parity
June 23, 2009 PVDIS at 12 GeV 3
PV Asymmetries: Any Target
(gAegV
T +β gVegA
T)
•The couplings g depend on electroweak physics as well as on the weak vector and axial-vector hadronic currentweak vector and axial vector hadronic current •Both new physics at high energy scales as well as interesting features of hadronic structure come into play•A program with many targets and a broad kinematic range can
June 23, 2009 PVDIS at 12 GeV 4
g y g guntangle the physics
Electron-Quark PhenomenologyAA
V
V
V A
Moller PV is insensitive to the Cij
C1u and C1d will be determined to high precision by Qweak, APV Cs
C2u and C2d are small and poorly known: one combination can be accessed in PV DIS
New physics such as compositeness, leptoquarks:
Deviations to C and C might be fractionally large
June 23, 2009 PVDIS at 12 GeV 5
Deviations to C2u and C2d might be fractionally large
Deep Inelastic Scatteringe-
X
e-
Z* γ*APV =
GFQ2
2παa(x) + Y (y) b(x)[ ]
a(x) and b(x) contain quark
distribution functions fi(x)
iii fff ±≡±
a(x) =C1i Qi fi
+(x)i
∑Qi
2 fi+(x)
i∑
N X
y ≡1− ′ E / E b(x) =C2i Qi fi
− (x)i
∑Qi
2 fi+ (x)
i∑
x ≡ xBjorken
iii fff
For an isoscalar target like 2H, structure functions largely cancel in the ratio at high x
i i
a(x) =3
10(2C1u − C1d ) 1+
2s+
+ d+
⎛⎝⎜
⎞⎠⎟
6.0at high x
b(x) =3
10(2C2u − C2d )
uv + dv
u+ + d+
⎛⎝⎜
⎞⎠⎟
+L
At high x, APV becomes independent of x, W, with well-defined SM prediction for Q2 and y
( )10
( 1u 1d )u+ + d+⎝⎜ ⎠⎟
0
10 u + d⎝ ⎠1
C2q inaccessible in elastic scattering
June 23, 2009 PVDIS at 12 GeV 6
DIS at high x (Approved)
2C2u − C2d 0 14 0 5% fractional precision on the2u 2d
2C1u − C1d
~ 0.14
δ 2C2u − C2d( )2C − C( ) ~ 5%
δ APV( )A
~ 0.5%
0.5% fractional precision on the asymmetry is needed!
2C2u − C2d( )APV
Feasible (in narrow kinematics) with existing JLab spectrometers.Feasible (in narrow kinematics) with existing JLab spectrometers.
Hall C HMS / SHMS spectrometers
JLab 11 GeV proposal: Conditional approvalPaschke, Reimer, Zheng et al.
• Experimental systematic errors challenging
• Averaged over large Q2, W, and x range
June 23, 2009 PVDIS at 12 GeV 7
PVDIS with SOLID• Solenoid (from BaBar, CDF or CLEOII ) contains low energy backgrounds (Moller, pions, etc)trajectories measured after baffles • Fast tracking, particle ID, calorimetry, •and pipeline electronics• Precision polarimetry (0.4%)
• High Luminosity on LH2 & LD2
• Better than 1% errors for small bins• x range 0 25 0 75• x-range 0.25-0.75• W2 > 4 GeV2
• Q2 range a factor of 2 for each
June 23, 2009 PVDIS at 12 GeV 8
• Moderate running times
Statistical Errors (%) vs KinematicsF SOLID S t tFor SOLID Spectrometer
Error bar σA/A (%)shown at center of binsin Q2, x
4 months at 11 GeV
2 months at 6.6 GeV
June 23, 2009 PVDIS at 12 GeV 9PAC34
Why do we need so many data i ?points?
• Possible new physicsPossible new physics– New interactions
Charge symmetry violation (CSV)– Charge symmetry violation (CSV)– Higher twist effects
Like neutron beta decay experiments:y pmany diverse physics topics
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Sensitivity: C1 and C2 Plots
World’s data6 GeV
World s data
PVDIS
Qweak PVDISPrecision Data
Cs
June 23, 2009 PVDIS at 12 GeV 11
Search for CSV in PV DIS•u-d mass difference•electromagnetic effects
up (x) = dn (x)?d p (x) = un (x)?
δu(x) = up (x) − dn (x)δd(x) = d p (x) − un (x)
•Direct observation of parton-level CSV would be very exciting!•Important implications for high energy collider pdfs•Could explain significant portion of the NuTeV anomalyp g f p f y
For APV in electron-2H DIS: dudu
AAPV
+−
=δδδ 28.0
PV duAPV +
Sensitivity will be further enhanced if u+d falls off more rapidly than δu-δd as x → 1
June 23, 2009 PVDIS at 12 GeV 12
CSV Theory and Data
90% conf limitBroad minimum
(90% C.L.)
fully explains NuTeV
Analytic calculation
MRST PDF global with fit of CSV
doubles NuTeV deviationy
similar to global fit
Martin, Roberts, Stirling, Thorne [Eur Phys J C35, 325 (04)]:
June 23, 2009 PVDIS at 12 GeV 13
Sensitivity with PVDISSensitivity with PVDIS
RCSV =δ APV x( )A ( )
= 0.28δu x( )− δd x( )
( ) d( )June 23, 2009 PVDIS at 12 GeV 14
CSV APV x( ) u x( )+ d x( )
Higher TwistSubject of recent workshop at Madison,
Wisconsin
≠
• APV sensitive to diquarks: ratio of weak to electromagnetic charge depends on amount of coherence (elastic He vs PVDIS)• Do diquarks have twice the x of single quarks?• If Spin 0 diquarks dominate, likely only 1/Q4 effects
June 23, 2009 PVDIS at 12 GeV 15
Need Full PhenomenologyNeed Full Phenomenologyγγσ2 )1(22 FxyMFd
⎥⎤
⎢⎡ LRRFF σγγ →+ )1(γγσ
21 )2
1(22 FE
xyMyy
xyFdxdyd
EM
−−+∝⎥⎦
⎤⎢⎣
⎡
22 VMGd ⎤⎡
T
LRRFFσ
γγ =→+= )1(21
}])2
1(22{[22 21
2ZZ
AZ
FE
xyMyy
xyFgGdxdyd γγ
γ πασ
−−+−∝⎥⎦
⎤⎢⎣
⎡
2 AGd ⎤⎡ Th 5
])2([22 3
2Z
VZ
FyxgGdxdyd γ
γ πασ
−−∝⎥⎦
⎤⎢⎣
⎡
V
There are 5relevant structure
functions
EM
AZ
VZPV
BAσ
σσ γγ += EM
VZxa
σσγ=)(
EM
AZxbyf
σσ γ=)()(
BIG Small; use ν data
June 23, 2009 PVDIS at 12 GeV 16
EM BIG Small; use ν data(Higher twist workshopat Madison, Wisconsin)
Best HT Data
F d i t th ti
Best HT Data
F2 dominates the cross section
Higher twist is clearlyHigher twist is clearlyseen at the PVDIS kinematics. What
can we add?can we add?
Analysis ofBlumlein and
BotcherJune 23, 2009 PVDIS at 12 GeV 17
Botcher
MRST Fits
F2(x,Q2)=F2(x)(1+D(x)/Q2) Q2=(W2-M2)/(1/x-1) Q2min=Q2(W=2)
x D(x) D(x) Q2min D/Q2
min(%) D/Q2min(%)
LO NNNLO LO NNNLO
2( ) 2( )( ( ) )
0.1-0.2 -.007 0.001 0.5 -14 20.2-0.3 -.11 0.003 1.0 -11 0.00.3-0.4 -.06 -0.001 1.7 -3.5 -0.50.4-0.5 .22 0.11 2.6 8 40.5-0.6 .85 0.39 3.8 22 100.6-0.7 2.6 1.4 5.8 45 24
MRST, PLB582,222 (04)
0.7-0.8 7.3 4.4 9.4 78 47
APV=APV(1+C(x)/Q2)
June 23, 2009 PVDIS at 12 GeV 18
F2D(x): All x on Same ScaleF2D(x): All x on Same Scale
Order of DGLAPinfluences size
of HTof HT
Higher twistf ll l lfalls slowly
compared to PDF’sat large x.
June 23, 2009 PVDIS at 12 GeV 19
D(x) versus xD(x) versus x
If C(x)~D(x), there is largesensirtivity al large x.
June 23, 2009 PVDIS at 12 GeV 20
Why HT in PVDIS is SpecialWhy HT in PVDIS is Special∫ ⋅+ 4|)0()()0()(| xdeDjxJJxjDl xiqνμνμ
μν
Bjorken, PRD 18, 3239 (78)
xdeDVxVDlVV xiq 4|)0()(|∫ ⋅= νμ
∫∫
⋅∝
4|)0()(|
|)()()()(|
deDjxjDl
jjA
xiqνμμν
μν
( ) ( )dduuSdduuV γγγγ +=⇔−=
Wolfenstein,NPB146, 477 (78)
xdeDVxVDlVV q|)0()(|∫= μμν
( ) ( )dduuSdduuV μμμμμμ γγγγ +=⇔=
SSVV
SSCCVVCCA
dudu
1
)(31)( 1111 ++−
= Zero in QPMIsospin decomposition SSVV31+
xdeddxuxuDlSVSVSSVV xiq 4)0()0()()(|))(( ⋅∫∝+−=− νμμν γγ
Zero in QPMIsospin decompositionbefore using PDF’s
Higher-Twist valancequark-quark correlations
HT in F2 may be dominated by quark-gluon correlations
Vector-hadronic piece only
June 23, 2009 PVDIS at 12 GeV 21
p y
Use ν data for small b(x) term.
Quark-Quark vs Quark-GluonQuark Quark vs Quark GluonWhat is a true
Parton Modelor
leading twistQuark-gluondiagram
quark-gluonoperator?
Di-quarksQuark-gluon operators
correspond to transverse momentum
QCD equationsof motion
June 23, 2009 PVDIS at 12 GeV 22
transverse momentum
Test QuestionsTest Questions1. Which diagram is HT?2 Is the HT diagram qq or qg?2. Is the HT diagram qq or qg?
DGLAP Evolution
June 23, 2009 PVDIS at 12 GeV 23
Diagrams (a)-(c) cancel in APV
Coherent Program of PVDIS S dStudy
Strategy: requires precise kinematics and broad range
⎥⎦
⎤⎢⎣
⎡+
−+= 2
23)1(11 x
QxAA CSVHT ββFit data to:
C(x)=β /(1 x)3
• Measure AD in NARROW bins of x, Q2 with 0.5% precision• Cover broad Q2 range for x in [0.3,0.6] to constrain HT
C(x)=βHT/(1-x)3
Cover broad Q range for x in [0.3,0.6] to constrain HT• Search for CSV with x dependence of AD at high x• Use x>0.4, high Q2, and to measure a combination of the Ciq’s
x y Q2
New Physics no yes noCSV yes no no
June 23, 2009 PVDIS at 12 GeV 24Higher Twist yes no yes
Other TargetsOther Targets• Hydrogen: d/uHydrogen: d/u• EMC effect
N Z l i• N≠Z nuclei
June 23, 2009 PVDIS at 12 GeV 25
PVDIS on the Proton: d/u at High x
)(910)( xdxu +)(25.0)()(91.0)()(
xdxuxdxuxaP
++
≈
Deuteron analysis has largenuclear corrections (Yellow)
APV for the proton has no such corrections 3-month runsuch corrections
(complementary to BONUS)
June 23, 2009 PVDIS at 12 GeV 26
The challenge is to get statistical and systematic errors ~ 2%
CSV in Heavy Nuclei: EMC EffectCSV in Heavy Nuclei EMC Effect
Additional possible
application of
Isovector-vector meanfield (Cloet
5%
application of SoLID
field. (Cloet, Bentz,
and Thomas)
June 23, 2009 PVDIS at 12 GeV 27
SoLID SpectrometerSoLID SpectrometerGas Cerenkov
Shashlyk
June 23, 2009 PVDIS at 12 GeV 28Baffles
GEM’s
P. Bosted, J. P. Chen, E. Chudakov, A. Deur,
O. Hansen, C. W. de Jager,
L. El Fassi, R. Gilman, R. Ransome, E. Schulte
Rutgers
P. MarkowitzFlorida International
X Jiang
K. Grimm, K. Johnston, N. Simicevic, S. WellsLouisiana Tech
CollaborationO. Hansen, C. W. de Jager,
D. Gaskell, J. Gomez, D. Higinbotham, J. LeRose,
R. Michaels, S. Nanda, A. Saha, V. Sulkosky,
B. Wojtsekhowski
RutgersW. Chen, H. Gao, X. Qian,
Y. Qiang, Q. YeDuke University
K. A. Aniol C lif i St t
X. JiangLos Alamos
W. KorschUniversity of
Kentucky
Louisiana TechO. Glamazdin, R.
PomatsalyukNSC Kharkov
Institute for Physics and TechnologyJefferson Lab
P. A. Souder, R. Holmes Syracuse University
K. Kumar, D. McNulty, L. Mercado, R. Miskimen
California StateG. M. Urciuoli
INFN, Sezione di Roma
A. Lukhanin, Z. E. Meziani,
J. Erler Universidad Autonoma
de MexicoM. J. Ramsey-Musolf
University of
and TechnologyZ. G. Xiao
Tsinghua UniversityB.-Q. Ma, Y. J. Mao
Beijing UniversityX M Li J L S Zh
,U. Massachusetts
H. Baghdasaryan, G. D. Cates,D. Crabb, M. Dalton, D. Day,
N. Kalantarians, N. Liyanage, V. V. Nelyubin, B. Norum,
B. SawatzkyTemple University
P. M. King, J. RocheOhio University
E. Beise
University of Wisconsin
C. KeppelHampton UniversityH. Lu, X. Yan, Y. Ye, P. ZhuUniversity of Science
X. M. Li, J. Luan, S. ZhouChina Institute of
Atomic EnergyB. T. Hu, Y. W. Zhang,
Y. Zhangy , ,K. Paschke, S. Riordan,
O. A. Rondon, M. Shabestari,J. Singh, A. Tobias, K. Wang,
X. ZhengUniversity of Virginia
E. BeiseUniversity of
MarylandW. Bertozzi, S. Gilad,
W. Deconinck, S. Kowalski, B. Moffit
University of Science and Technology of
ChinaN. Morgan, M. PittVirginia Tech
J C P
Lanzhou UniversityC. M. Camacho, E. Fuchey,
C. Hyde, F. ItardLPC Clermont,
Université Blaise y gJ. Arrington, K. Hafidi,
P. E. Reimer, P. SolvignonArgonne
D. Armstrong, T. Averett, J. M. Finn
B. Moffit MIT
Benmokhtar, G. Franklin, B. Quinn
Carnegie MellonG Ron
J.-C. PengUniversity of Illinois
H. P. Cheng, R. C. Liu, H. J. Lu, Y. Shi
Huangshan University
PascalA. Deshpande
SUNY Stony BrookA. T. Katramatou,
G. G. Petratos
June 23, 2009 PVDIS at 12 GeV 29
William and Mary P. Decowski
Smith College
G. RonTel Aviv University
T. HolmstromLongwood University
g yS. Choi, Ho. Kang, Hy. Kang
B. Lee, Y. OhSeoul National
University J. Dunne, D. Dutta
G. G. PetratosKent State University
J. W. MartinUniversity of
Winnipeg
STATUS and PLANSSTATUS and PLANS• Jan 2009: Conditional approvalJan. 2009: Conditional approval• Jan. 2010: Seek full approval
F ll 20 0 Di ’ i• Fall 2010: Director’s review• Spring 2011: Seek CD0
June 23, 2009 PVDIS at 12 GeV 30
Kinematics at large xKinematics at large x
June 23, 2009 PVDIS at 12 GeV 31
BafflesBaffles
Rates in detectors reducedby more than 10
June 23, 2009 PVDIS at 12 GeV 32
Physics Resolution (%) vs D R l i d A lDetector Resolution and Angle
p θ
Q x2
June 23, 2009 PVDIS at 12 GeV 33
ConclusionsConclusions• PVDIS addresses many physics topicsPVDIS addresses many physics topics
– Electroweak couplingsCSV at the quark level– CSV at the quark level
– Di-quarksd/ f th t– d/u for the proton
– Nuclear-induced CSVSO d li h• SOLID spectrometer can deliver the physics
June 23, 2009 PVDIS at 12 GeV 34
Figure of Merit vs Scattering A lAngle
June 23, 2009 PVDIS at 12 GeV 35
Lots of Pions at Low EnergiesLots of Pions at Low Energies
Need gas Cerenkovplus shower counterplus shower counter
with preradiator
June 23, 2009 PVDIS at 12 GeV 36
Pion Rejection: Shashlik DetectorPion Rejection Shashlik Detector
Total Pion Signal Epreshower/Etotal
June 23, 2009 PVDIS at 12 GeV 37
g Epreshower/Etotal