Kaon_LT Experiment

{{>toc}}

h1. *Kaon LT Meetings*

----

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of Andres' slides on elastic W calculation in hcana - initial issue with negative W values seems to be due to outdated information in standard.kinematics file.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) 

----

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)

----

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

----

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

----

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)

----

h2. May 31, 2018

*Links to talks->* "Samip":https://redmine.jlab.org/documents/30

----

h2. June 28, 2018

*Links to talks->* "Richard":https://redmine.jlab.org/documents/34

*Action Items:*

* Develop and post shift schedule. Send out request. Find out who is KAONLT liaison (Tanja)

* Contact potential run coordinators. (Tanja)

* Aerogel tray exchange for start of experiment and coordination of future exchanges (Vladimir)

* Update runplan and prepare documents needed for shift crew, e.g. run sheets (Garth)

* Set up a web page to collect and link from Redmine - How-To documents, initial calibrations, etc. (Garth, Richard)

* Adapt luminosity scan script to calculate kaon yields by run number for use during experiment by shift crew - has to be simple to use. (Richard)

* Develop trigger/detector checkout plan (Tanja, initial draft)

** Are all experts available at run start, experts needed: coincidence timing , Harp Scans, BCM calibrations, ...

* Find out from JLab what the anticipated settings are for limit switches for both spectrometers and for separation angle in between them. Also find out what magnet cycling procedure should be used for L/T quality separation data (Tanja)

* Find out if all aerogel trays needed for experiment can be stored inside Hall C to avoid having to open truck ramp (Vladimir)

*Analysis Updates:*

* 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.

----

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

----

h2. August 3, 2018

*Ongoing Tasks->* #381 #382 #383

*Links to talks->*

----

h2. August 8, 2018

*Ongoing Tasks->* #381 #382 #383 #404 #405 #406

----

h2. August 21, 2018

*Ongoing Tasks->* #381 #382 #383 #404 #405 #406

----

h2. February 4, 2019

*Links to talks->* "Richard":https://redmine.jlab.org/documents/43

----