Kaon LT Meetings » History » Revision 4
Revision 3 (Richard Trotta, 07/16/2018 12:34 PM) → Revision 4/947 (Richard Trotta, 07/16/2018 12:36 PM)
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h1. *Kaon LT Meetings*
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h2. February 22, 2018
*Links to talks->* "Andres":https://redmine.jlab.org/documents/19
* 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of Andres' slides on elastic W calculation in hcana - initial issue with negative W values seems to be due to outdated information in standard.kinematics file.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)
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h2. March 29, 2018
*Links to talks->* "Richard, ":https://redmine.jlab.org/documents/16 "Samip":https://redmine.jlab.org/documents/27
* 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)
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h2. April 26, 2018
*Links to talks->* "Richard,":https://redmine.jlab.org/documents/18 "Ryan, ":https://redmine.jlab.org/documents/20 "Samip":https://redmine.jlab.org/documents/25
* 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
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h2. May 10, 2018
*Links to talks->* "Hem":https://redmine.jlab.org/documents/24, "Richard":https://redmine.jlab.org/documents/23, "Ryan, ":https://redmine.jlab.org/documents/20 "Samip":https://redmine.jlab.org/documents/26
* 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
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h2. May 17, 2018
*Links to talks->* "Richard":https://redmine.jlab.org/documents/29, "Ryan":https://hallcweb.jlab.org/DocDB/0009/000968/001/Presentation.pdf, "Samip":https://redmine.jlab.org/documents/30
* 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)
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h2. May 31, 2018
*Links to talks->* "Samip":https://redmine.jlab.org/documents/30
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h2. June 28, 2018
*Links to talks->* "Richard":https://redmine.jlab.org/documents/34
* 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.
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h2. July 11, 2018
*Ongoing Tasks->* #381 #382 #383 #384
*Action items:*
* Update run plan, e.g. add prescales (Garth)
* Check on details of: magnet cycling procedure, minimum angles, MCC fringe field steering, beam energy measurements, optics checks (Tanja)
* Identify additional run coordinators (Tanja)
* Encourage collaborators to take shifts, e.g. FIU (Pete)
* Draft email about shifts etc. to collaboration (Tanja)
* Develop diagnostic scripts and kaonLT specific (Richard, Ryan)
* Continue documentation development, e.g. checklist, shift taker instructions, HowTo or link to generic Hall C HowTo, task list, web page (Richard, Garth)
*Discussions:*
* SHMS Aerogel Cherenkov: tray has been changed to SP-11 on 10 July, nominal time for change is 8 hours, one tray can stay in the hall to minimize overhead
* HGC: waiting for re-installation
* Trigger checkout: main items to keep in mind: fADC thresholds, timing HMS/SHMS - leading arm, possible rate limitations
* Shifts
* Diagnostics scripts and documentation
* Personnel schedules
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