2005 HAPPEX Run Summary2005 HAPPEX Run Summary

Kent PaschkeKent Paschke

HAPPEX Collaboration MeetingHAPPEX Collaboration Meeting

December 3, 2005December 3, 2005

December 3, 2005December 3, 2005Kent Paschke HAPPEX Collaboration Kent Paschke HAPPEX Collaboration

MeetingMeeting

Run SummaryRun Summary

Helium Scheduled: 48 days

Actual: 55 days

July 9 – Aug 7Aug 7 – Aug 31

July 28 – Sept 1Sept 9 – Sept 27

Late start due to • installation• sweeper/septum and spectrometer commissioning• beamline commissioning

Hydrogen

Scheduled: 39 days

Actual: 36 days

Oct 15 – Nov 23

Oct 16 – Nov 21

Last day for PREx tests

~18 day “parasitic” extension was very important

December 3, 2005December 3, 2005Kent Paschke HAPPEX Collaboration Kent Paschke HAPPEX Collaboration

MeetingMeeting

Run SummaryRun Summary

Helium Scheduled:~800 hoursDelivered: ~1000 hours

Actual: Good pairs: ~34M ~630 hours

Hydrogen

Scheduled:~450 hoursDelivered: ~580 hours

Actual : Good pairs: ~24M ~440 hours

(+ background studies, calibration, etc)

(+ background studies, calibration, etc)Total Charge: 86.7 C

P2Q*L ~ 59% (not counting 2004)

Total Charge: 79.7 C P2Q*L ~ 35% (not counting 2004)

December 3, 2005December 3, 2005Kent Paschke HAPPEX Collaboration Kent Paschke HAPPEX Collaboration

MeetingMeeting

Online Raw AsymmetryOnline Raw Asymmetry

Helium

Hydrogen

<A> <A> (ppm)(ppm)

RMS RMS (ppm)(ppm)

Regress Regress CorrectionCorrection

LeftLeft 4.38 ± 0.264.38 ± 0.26 14951495 0.43 ppm0.43 ppm

RightRight 3.45 ± 0.253.45 ± 0.25 14661466 -0.18 ppm-0.18 ppm

AvgAvg 3.91 ± 0.183.91 ± 0.18 10471047 0.12 ppm0.12 ppm

<A> <A> (ppm)(ppm)

RMS RMS (ppm)(ppm)

Regress Regress CorrectionCorrection

LeftLeft -1.32 ± 0.15-1.32 ± 0.15 757757 0 ppb0 ppb

RightRight -1.46 ± 0.16-1.46 ± 0.16 762762 5 ppb5 ppb

AvgAvg -1.39 ± 0.11-1.39 ± 0.11 537537 3 ppb3 ppb

December 3, 2005December 3, 2005Kent Paschke HAPPEX Collaboration Kent Paschke HAPPEX Collaboration

MeetingMeeting

Background StudiesBackground Studies

Helium

Hydrogen

• Al Background • ~1.8%• Integrating + Counting measurement

• Inelastic spectra• Dipole scan for rescattering probability• Total: ~ 4 shifts?

• Likely results: <2% He QE, ~1.8% Al, <0.6% rescatter

• Al Background • ~0.7%• Integrating + Counting measurement

• Inelastic spectra• Dipole scan for rescattering probability• Total: ~ 3 shifts?

• Likely results: ~0.7% Al, <0.2% rescatter

December 3, 2005December 3, 2005Kent Paschke HAPPEX Collaboration Kent Paschke HAPPEX Collaboration

MeetingMeeting

Transverse AsymmetryTransverse Asymmetry

• PV < 2%, Aperp ~ 6.5 ppm• AL – AR is small

Hydrogen

Helium• PV ~ 3%, AT ~ 13 ppm -> suggests 0.8 ppm difference• AL – AR is large (0.9 ppm)• Sign is correct!

December 3, 2005December 3, 2005Kent Paschke HAPPEX Collaboration Kent Paschke HAPPEX Collaboration

MeetingMeeting

Correlated NoiseCorrelated Noise

Hydrogen

Helium

AL–AR RMS = 1066 ppm

“True” width ~ 533 ppmAverage width ~ 537 ppmCorrelated noise ~ 65 ppmDouble Difference suggests BCM noise ~ 56 ppm

AL–AR RMS = 1912 ppm

“True” width ~ 956 ppmAverage width ~ 1047 ppmCorrelated noise ~ 430 ppm

Double Difference suggests BCM noise <70 ppm

Likely culprit: Density Fluctuations

December 3, 2005December 3, 2005Kent Paschke HAPPEX Collaboration Kent Paschke HAPPEX Collaboration

MeetingMeeting

Polarimetry ResultsPolarimetry Results

Hydrogen

Helium

December 3, 2005December 3, 2005Kent Paschke HAPPEX Collaboration Kent Paschke HAPPEX Collaboration

MeetingMeeting

Physics AsymmetryPhysics Asymmetry

Hydrogen

HeliumAPV: ~ 0.21 ppm (3.5%)GE

s: ~ 0.014

2004:

APV: ~ 0.84 ppm (11.2%)GE

s: ~ 0.042

APV: ~ 0.12 ppm (8%)GE

s+0.084GMs: ~ 0.012

2004:

APV: ~ 0.24 ppm (17%)

GEs+0.080GM

s: ~ 0.025

NOTE: Statistical error only!

Systematic error will likely increase Helium error bar by ~40%, and Hydrogen by about 25%