High Luminosity Spectrometer for PVDIS in JLab Hall A - PowerPoint PPT Presentation

Title: High Luminosity Spectrometer for PVDIS in JLab Hall A


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High Luminosity Spectrometer for PVDIS in JLab
Hall A

• Rutgers town meeting

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PVDIS and Hadronic Structure
For PVDIS
2H and Charge Symmetry
See quark-quark Correlation In higher twist
Measure d/u For 1H
Higher Twist
No nuclear Correction
Need multiple sub- APV measurements at
numerous x-Q2 bins
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High acceptance/ high luminosity Spectrometer for
Hall A at JLab
Price10M
x y Q2 p d
Higher twist Yes No Yes X
CSV Yes? No No X
d/u Yes No No X
SM Test No Yes No X
Projected fractional APV errors in
Kinematic coverage
60 days ea. 8.8 and 11 GeV
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Backups
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Observables in Asymmetries for PV e- DIS
e-
e-
?
Z
X
N
fi(x) are quark distribution functions
For an isoscalar target like 2H, structure
functions largely cancel in the ratio
(2C2u-C2d)/(2C1u-C1d)0.136
Especially for xgt0.5 or so
APV becomes independent of x, Q2, W, and depends
only on y
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Untangle Many Topics in Hadronic and Electroweak
Physics
x y Q2 p d
Higher twist Yes No Yes X
CSV Yes? No No X
d/u Yes No No X
SM Test No Yes No X
Higher Twist
Need many points with lt0.5 precision
See quark-quark correlation
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Charge Symmetry Violation in PV DIS
For APV in e--2H DIS (dAPV0 without CSV)

• u-d mass difference
• electromagnetic effects

• Direct observation of parton-level CSV would be
  very exciting!
• Important implications for high energy collider
  pdfs
• Could explain significant portion of the NuTeV
  anomaly

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High acceptance/ high luminosity Spectrometer
forHall A at JLab
CDF or BaBar Solenoid?
Price10M
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PV for e--Nucleon Has Four Couplings
C1s are large and precisely measured (key to
measuring hadronic structure)
C2s are small but poorly measured (almost
virgin territory for Standard Model test)
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Kinematic acceptance
Large angles required for large x
Wgt2
Good resolution needed to maintain integrity of
the bins
?gt35o
Tlt20o