• Table of contents
• Kaon LT Meetings
  • February 22, 2018
  • March 29, 2018
  • April 26, 2018
  • May 10, 2018
  • May 17, 2018
  • May 31, 2018
  • June 28, 2018
  • July 11, 2018

Kaon LT Meetings¶

February 22, 2018¶

Links to talks-> Andres

• Discussion of Andres' slides on elastic W calculation in hcana - initial issue with negative W values seems to be due to outdated information in standard.kinematics file. Additional investigation ongoing.
• Brief description of Samip's work - working on coincidence timing decoding with JLab staff and re-optimization of kinematics
• Discussion of Richard's slides on run plan kinematics and preparations -
  • everyone agrees that in general want to have as many L/T cross section separations as possible in a robust run plan balancing statistics vs. systematics
  • before actual run may want to do a 3D optimization in all kinematic variables to get the best possible delta(epsilon) for the L/T separations
  • for each setting will need 1-2 shifts for calibrations - need to negotiate with other experiments in run group
  • kinematics plots W-Q2 show that still need to do some optimization
  • run sheets: include raster size, update coincidence count labeling, and carbon target labeling
• Discussion of next meeting. Garth at JLab 8-16 March - might have meeting during that time.

• Action Items:
  • Post slides/notes from this meeting and procedure to set up hcana in Redmine (Tanja)
  • Update run sheet and kinematic optimization for W/Q2 (Garth)
  • Circulate elastic calculations for kinematic settings (Samip)
  • Continue investigation of elastic data and run plan kinematics (Andres/Richard)
  • Test software installation instructions (Pete)
  • Draft email to JLab management about need for small angle beam pipe - need to have HMS minimum angle of less than 13 degrees for kaon L/T separations (Tanja)

March 29, 2018¶

Links to talks-> Richard, Samip

• Details of adding points to fall run plan - will be ready sooner, likely in week of 4/1 (Garth, Samip, Tanja)
• Luminosity scans (Ryan, Andres, Richard, Pete)
• Macros, SIDIS analysis (Hem, Anashe)
• Elastic data (TBD)

April 26, 2018¶

Links to talks-> Richard, Ryan, Samip

• Discussion luminosity scan analysis (earlier scan) - Richard
  • Shown is a scaler-based analysis using scalers from report file and from ROOT tree - the values are different, why that is has to be checked
  • Notes on efficiencies in report file:
    • DT (EDTM) is not electronic deadtime. Instead use for now 50ns* trigger rate for HMS and 100ns* trigger rate for SHMS
    • Cherenkov efficiency seems low (check if that is due to PID, thresholds, pi/e, etc)
    • Tracking efficiency needs to be checked
    • 3/4 trigger efficiency seems ok
• Discussion luminosity scan analysis (later scan) - Ryan
  • Fewer carbon runs than earlier scan
  • Shown is a tracking-based analysis using data from the ROOT trees
  • First results for carbon, LH2, and LD2, but efficiencies need to be checked
• SIDIS analysis - Hem
  • Shown is a data/MC comparison for different kinematic settings. Agreement in shape is very good. Normalization has yet to be applied.
  • Discussion about agreement in z and apparent offset - relation of this offset with spectrometer offset
• Analysis of exclusive events in SIDIS - Samip
  • Shown is a look at the first kaon events in exclusive limit of SIDIS data
  • Ongoing work on implementing coincidence time into tree
• Discussion of run plan, and in particular possible low Q2/low energy
  • Assume that kaon low Q2=0.4 already included - have kinematics with specified beam energies, if needed
  • For pion form factor and LT, have two possible settings that can use the prescribed beam energies: Q2=1.45 and 0.35 GeV2 - prioritize towards the higher Q2 as not as sensitive to offsets
  • Garth will put this together in a draft email

May 10, 2018¶

Links to talks-> Hem, Richard, Ryan, Samip

• Luminosity Scans January 2018 (Richard)
  • Tracking-based analysis for Runs 1415-1423, .. for now focus on HMS, typical HMS S1X rates are <
  • Cuts applied: PID for electrons (Cer, Cal), acceptance (delta)
  • Efficiency calculation was investigated in detail and applied using scalers from trees
  • Results for carbon (normalized to 30uA) show large variation - need to understand
  • Next steps:
    • Double check calculation of computer lifetime, look for differences in TRIG and PRETRIG scalers
    • Check stability of pre-scale (Ryan saw changes within runs)
    • Check if detector calibrations for runs are implemented correctly
    • Analyze with Ryan's cuts

• Luminosity Scans April 2018 (Ryan)
  • Confirms Richard's earlier finding that scaler-based analysis is not reliable and that it's best to analyze event-by-event
  • Tracking-based analysis for runs 2073-2095
  • Cuts applied: PID for electrons (TOF, Cal, Chi2), acceptance (delta and angles), BCM4a
  • Included most recent detector calibrations in replay of these runs
  • Efficiencies from report file mainly, may need to update tracking efficiency implementation
  • Found that calculations of computer deadtime requires different set of scalers for runs from January to those from April 2018
  • Results show carbon yields consistent with unity within error (0.5% error bars), and boiling for hydrogen and deuterium
  • Next steps:
    • Check tracking efficiency

• Global comments on Luminosity Scans (so far)
  • April 2018 scans show hydrogen and deuterium target boiling on level of 3-4%, Carbon is consistent with no boiling, as expected - based on description, new targets are expected to have less boiling than those used previously, e.g. in FPI2. Double check this.
  • Efficiencies in report files need to be updated, e.g. CPU deadtime (Richard)
  • Check if BCM4a is the one closest to the target - get a map of the hall (Richard, Ryan)
  • Uncertainties on current
  • Detector calibrations
  • HMS vs. SHMS

• eK+ coincidence time from SIDIS Spring 2018 run (Samip)
  • Worked with Mark Jones on coincidence time calculation - now available in hcana (see Samip's 10 May 2018 email for more details)
  • runs used in this analysis: 3423 with Q2=3.1 GeV2 and W=2.78 GeV
  • Coincidence time spectrum shows peak separations >2 ns corresponding to different accelerator frequency
  • Missing mass spectra: Kaon peak clearly visible, also see pions even after cuts
  • Found that pions appear localized in phase space - seems to be due to end point in kinematic phase space
  • Next steps:
    • Look for a run with kaon momentum closer to 3 GeV/c (aerogel threshold is ~3 GeV/c for kaons for n=1.015)

• Yield normalized ratios from SIDIS (Hem)
  • Yield ratios of data to MC match well in shape, but normalization seems not quite right
  • Next steps:
    • Check if efficiencies, currents, run time etc. are taken into account correctly

May 17, 2018¶

Links to talks-> Richard, Ryan, Samip

• Luminosity scans (Richard, Ryan)
  • Carbon scan from April seems consistent with no boiling, LH2 and LD2 show deviation from unity, should check effect of EDTM events on efficiencies
  • Carbon scans from January (low rates) have large deviations from unity, in particular behavior at higher currents (>40uA), e.g. cpu dead time, that is not yet understood
  • discussion about pre-scale factors

• Discussion about Richard's script extracting and printing information from report files and trees including histograms
  • Add option for looking at yields with cuts on cointime, target window, and missing mass
  • Add option to look at real peak vs. background level

• H(e,e'p) kinematics investigation for fall run (Samip)
  • Optimal range is between electron angles of 17-20 degrees, time required ranges from ~1 hour at 17 degrees to ~3 hour at 20 degrees, other angles may be of interest for disentangling charge and current dependent effects

• Action Items
  • Luminosity scans at low rates from January (Richard)
  • Luminosity scans from April with corrected efficiencies, e.d. DT (Ryan)
  • H(e,e'p) and H(e,e') kinematics for upcoming Kaon LT run (Samip)
  • Kaon LT detailed run plan (Garth, Pete, Tanja)
  • Preparations, e.g. report files, diagnostic histograms and real time monitoring, shift worker instructions, optimization of trees (all)

May 31, 2018¶

Links to talks-> Samip

June 28, 2018¶

Links to talks-> Richard

• Ryan
  • resolving differences between his analysis and Richard's

• Richard
  • Discussed with Mark Jones and is cross checking his January luminosity scan analysis against Mark's. Realized that BCM calibrations (gains, offsets etc) are different - currently working on fixing that, presents current results - low curent point is ~10% below unity, discussion that this seems to indicate that BCM offsets are the issue as low current points would be most sensitive, is planning to also double-check the BCM calibration procedure - had discussion with Dave Mack at JLab
  • Presents a script developed for luminosity scans that determines yields for a run number input on command line. Discussion this could be good to adapt for kaon counting during experiment.

July 11, 2018¶

Link to talks->