Annual Review III Jeff Secrest November 21, 2003

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Annual Review IIIJeff SecrestNovember 21, 2003

• Outline
• Overview
• What is G0
• My work (injector, inelastic dilution factors,
  asymmetry analysis)
• The future

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Overview

• Summary past years (2001, 2002)
• Completed courses
• Required and elective
• Teaching obligation fulfilled
• Shift work
• E97-103 (Hall A)
• GEn-Day (Hall C)
• At Jlab helped assemble and test the NAFPD
• At Jlab worked in the injector

• This year (2003)
• The 1st eng run ended in January
• Analyzed and compiled results from the injector
  DAQ
• April APS Monitoring HC beam parameters in the
  CEBAF injector for the G0 experiment
• G0 Technote
• Built injector DAQ for the Test Cave
• Contributed to ana inel dil factors
• Submitted LANL preprint HUGS document on Weak
  interactions in Atoms and Nuclei
• Presented poster on G0 for DOE review
• Asymmetry analysis
• Contributions to 2nd eng prod run
• Find the DNL for a Grey-Noise run
• Extract inel dil fac from ROOT/DB
• Find cuts for from ROOT/DB

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My Thesis Experiment G0

• G0 is a PV elastic P scattering experiment to
  extract the strange nucleon form factors GSE
  and GSM
• Counting experiment
• 8 octants of 16 pairs of scintillator each
• Forward measurement Custom built electronics for
  the fact accumulation of data
• Discrimination of p and inel protons
• Backward measurement CEDs and Cerenkov detector
• Discrimination of inel protons and p
• Asymmetry Ameas -3.0 -40.0 ppm
• Error ?A 2.5 10-7
• N1013 to obtain a stat precision of ?A/A 5
• Luminosity L 2.1 1039 cm-2 s-1
• Beam Current I 40 µA
• Large acceptance 0.4-0.9 sr
• Electron Polarization Pe 77

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Parity Violating P Scattering

• Utilizing
• Flavor decomposition
• Charge symmetry

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Expected Results
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My Work Injector

• Motivated by ?A 10-7
• Strong constraints on beam parameters
• Requires control of beam properties at the origin
  (The CEBAF injector)

Need G0 injector DAQ to monitor the beam
parameters in the most critical part of the
machine
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Injector The Polarized Source
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Injector Controlling Helicity Correlated
Position Differences

• Require HC position differences lt 20 nm
• During the January run
• ?X , ?Y 50 nm
• Controlled via
• PZT mirror (position feed back) (Unstable! )
• Adiabatic damping (Not enough!)
• Subsequent work
• To understand the PZT Test Cave studies
• To understand adiabatic damping Accelerator has
  been trying to understand the injector
  betterclose interactions with G0

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Injector Controlling Charge Asymmetry

• Require HC charge asymmetry 1 ppm
• During the January Run
• ?Q 2 ppm
• Controlled via
• IA modulates the laser in a HC manner
• Induced position differences
• Aperture scraping
• Subsequent work
• TC IA realignment

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Injector Overview

• Analyzed and compiled results from this past
  years Engineering run
• Preliminary Beam Properties and Diagnostics
  Report for the G0 Fall 2002 Engineering Run
• G0 Technote
• April APS meeting
• Set up TC so that further studies could be made
  during this year
• IA alignment (for minimizing position
  differences)
• PZT stability

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My Work Inelastic Dilution Factors

• Inelastic Dilution Factor R

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Inelastic Dilution Factors NA DNL

• With exception of the 1st bin (by design) all the
  NA ToF bins should be 1 ns widedeviations from
  this is the DNL
• With uncorrected DNL, the NA inelastic dilution
  factors could not be extracted
• DNL corrected by utilizing
• Variable bin widths
• Normalization of the bins

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Inelastic Dilution Factors Extraction

• Used a 3 Gaussian fit (pion, inelastic proton,
  elastic proton)
• Could not extract inelastic dilution factors for
  all NA runs due to the DNL
• Had to assume the inelastic dilution factors were
  constant over the January engineering run

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Inelastic Dilution Factors Results

• Final errors

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Inelastic Dilution Factors Overview

• G0 technote
• Gave 2 talks at collaboration meetings on this
  topic
• For the 2nd Engineering and production run
• Electronics have been modified to minimize DNL
• DNL measurements will be made often
• Programs for 2nd Engineering run
• To find the NA DNL
• To find the inelastic dilution factors

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My Work Asymmetry Analysis

• Used a larger data set than what was used over
  the summer
• Ingredients for obtaining Ael
• Measured asymmetry Ameas
• Dilution factor R
• Background asymmetry Ainel

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Asymmetry Analysis from Ameas to APhys

• Raw measured asymmetry
• Correct for false asymmetries from HC beam
  properties
• Correct for background and its asymmetry
• Correct for beam polarization and radiative
  corrections

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Asymmetry Analysis Araw Under ?/2 Plate Reversal

• Over 50 hours of data
• 700 hours during the production run
• ?/2 Plate reversal used to check for systematic
  errors

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Asymmetry Analysis Results from January 2003

• No yield slope correction
• No radiative corrections
• Dead time correction
• Background correction
• Beam polarization correction

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My Thesis Progress

• Physics Motivation
• need to work on this
• Formalism
• Weak Interactions in atoms and nuclei The
  Standard Model and beyond
• Apparatus
• G0 Technote ,Tests of the G0 North American
  Focal Plane Detector
• G0 Technote Overview and How-to for the Injector
  DAQ
• Analysis
• G0 Technote on inelastic dilution factors
• Results
• Comparison of results with the Standard Model

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The Future

• Suggestions for other aspects of my thesis
• Timeline
• November G0 Engineering run finish analysis
• January G0 Engineering run Start work on
  Standard Model
• Febuary/March
• March Start work on thesis
• September Defend