Connor Graham's Analysis

This page summarises key points and events from my PhD analysis. My thesis topic is an analysis of 2017 data from the NA62 experiment at CERN, to make a measurement of the branching fraction K⁺→π⁺νν to 10% Standard Model sensitivity.

Timeline

Non-analysis work this week:

• Obtained new grid certificate and am in the process of converting it from .p12 to .pem for Dirac and updating my associated readme file [done]
  • VO Northgrid membership has expired, need to sort this out [should be ok actually, it's the old membership]
• Swapped my dosimeter as requested (for annual calibration and checks)
• Fixed the dates on the meeting slides

NA62 meetings

Analysis meetings:

18-19/10/17, 07-08/02/18, 25-26/04/18, 18-19/07/18, 24-25/10/18.

Collaboration meetings:

11-15/12/17, 5-9/03/18, 4-8/06/18, beginning of September in Pisa, 10-14/12/18.

Glasgow meetings:

Meeting slides are available in the shared directory under meeting_slides/

Upcoming: 10/11/17

Past: 20/10/17

Shifts

Night = 00:00 - 08:00, Day = 08:00 - 16:00, Afternoon = 16:00 - 00:00

2016:

Day 27/10 (shadow)

2017:

Practical training 04/07/17

Day 08/07 (shadow) | Night 10/07 | Afternoon 11/07 | Night 15/07 | Night 16/07 | Night 17/07 | Day 18/07

Afternoon 20/07 | Day 22/07 | Day 24/07 | Day 28/08 | Day 31/08 | Afternoon 10/08 | Day 21/08

Events and travel

PhD and Glasgow University related events:

Long Term Attachment at CERN: 27/06/17 - 12/18 (return date approximate)

Lancaster University for STFC HEP Summer School 03-15/09/17 | Helping with the particle physics masterclass for pre-university students 13/06/17 | CERN trip for analysis meeting etc. 22-26/05/17 | Residentail at Edinburgh University for SUPAHOW 25-27/04/17 | Helping on PhD interview day 15/02/17 | Edinburgh University for detectors lab 30/11/16 | CERN for account setup and visiting the main building 24-28/10/16

Seminars and other external events:

16/10/17 facebook live broadcast of the ISOLDE 50th birthday celebration

Talks and posters

11/09/17 poster presentation on NA62 at Lancaster University, 05/04/17 creative talk for the postgraduate leadership programme, 02/03/17 LHCb pentaquark talk for SUPADCL

Analysis

Currently working on:

Generating a K_μ2 normalisation sample to compare the ππ⁰ and μ⁺ν normalised branching ratio values, to determine if anything has been missed in the systematics.

• Step 1: Start generating a sample of K_μ2 data with PNN like cuts from one burst (current file) and organise some output histograms [in progress]
  • Write a new tree to group useful output [done along with a new function in the code]
  • Still to get started on PNN like cuts
• Step 2: Test on 100 bursts with HTCondor (Stoyan will send me the instructions readme and associated codes when required)
  • Refine cuts and output histograms etc...
• Step 3: Run on 1k bursts (average run) with HTCondor to try and get some good results
  • e.g. the number of kaon decays for K_μ2
• Important: The acceptance of each decay has to be studied carefully as not all elements cancel, so everything has to be considered for how it could affect the acceptance with respect to the other decay (PNN or K_μ2)

• Altering the Geant4 setup to change the hadronic interaction probability in GTK3 to 1
• Generating on the order of 100M events
• Comparing with data
• Aim: to make an estimation of this background for the PNN errors

Finished:

Generating a Pnn sample from the Kaon code given to me by Giuseppe.

• Build fails due to class conflict in the public directory files
  • Solution: fixed manually by Giuseppe in the codes, largely by replacing the conflicting "Particle" class with "MyParticle"
• Further run fails due to a special trigger issue not dependent on the build flag
  • Solution: a special trigger element of the code needs changing when swapping between MC and data files
• Now working on afs and should be able to set up on any other system (copy placed in: userDir2)

A test analyser, to understand how to generate an analyser from scratch and plot variables in the data files, using the framework as a basis.

• This analyser is now setup such that it builds and begins to run with the current setup, designed to record the number of spectrometer candidates, but it fails at runtime due to an issue with a special trigger which is not specifically used in the code.
  • Solution: frameworks are not yet completely backwards compatible, I need to use the --old-specialtrigger flag after "build" to get this to work

Thesis document

I've collected all the relevant guideline documents and found a LATEX template for a generic "science and engineering" thesis. I've made a draft copy, added some basic information, style (both in the code and pdf) and some preliminary chapter titles. I'll mostly work on this in the background at this stage, such as a little while on shifts or during long periods of travel.

Instructions:

NA62 framework and user directory: (may expand this into a complete section with the instructions written out to be easier to read)

Instruction file in the shared directory under: /readme/analysisbuild.txt

I'm currently using "NA62AnalysisBuilder.py build --old-specialtrigger --build-user-only -j 60 config" to build my config file

• --old-specialtrigger (explained above) is for backward compatibility with datasets that were filtered using an older revision
• --build-user-only speeds up the build if the framework is built and up-to-date (wouldn't advise this unless this analyser has been built at least once completely)
• -j 60 uses more cores to run the build, also speeding it up

Code

Current version of my K_μ2 normalisation sample code on 02/11/17 (runs with data and r1720 of the Git framework): /codes/kmu2norm/KaonEventAnalysis.cc (.hh also in this directory, as required to build)