End of term post-mortem

presentation -

ATLAS and me

Michael Nash

UCL RAL joint studentship

HEP computing - general Linux computing

bash and scripting

aliases

ssh

plus1 and lxplus

Compiling

gmake and makefiles

gcc

CVS and CMT

HEP computing - ATLAS Played with Athena, AthenaROOtT

ran through the tutorials successfully

haven't used in analysis yet, only 'played'

With supervisor's help (Bill Murray, RAL) checked

out and ran the tthhbb analysis on sample data.

Problems using the code

error in the code file I need(ed) to examine

compiler differences between UCL and RAL

unfortunate delay; had hoped for meaningful graphs

for today's talk

But why look at tthhbb code specifically?...

PhD topic, or ”why tthhbb?” Generally agreed with

supervisors that topic will be

ttH fully hadronic decays

modes

ttH Higgs leptonic and semileptonic modes under a lot of study

Why study fully hadronic?

higher rate

being neglected

Why hasn't it been studied?

higher backgrounds

hadronic mess/jets

ttH semileptonic mode

Most likely topology will be●2 b jets from the t → Wb

process●another 2 b jets from H

decay●each W can either decay

hadronically, producing a

jet, or leptonically

”why tthhbb?” cont'd tthhbb code designed to

work with leptonic and semileptonic decays of ttH events

plots prove I've done

work

disembowel code

use it to select ttH events

modify leptonic selection

part to select non-

leptonic event

After that, the real work

will begin...

(Naive) expectations of my PhD To use higher event rate of fully hadronic mode, one

must

increase purity and efficiency of cuts

investigate how jet algorithms work and how to apply

them

hopefully aid the creation of a new trigger and

increase in data

Not well investigated topic + hard work = a PhD?

This is assuming that I pass my exams, the lectures for

which have (to my annoyance) eatne this entire term.

Physics interlude? Possible side project to investigate the

workings and calibration of ATLAS

KL regenerated to superposition of K

L and K

S when

interact with matter i.e. at the tracker layers

reconstruct kaon vertices to examine both ATLAS

radiation depth simulation and other tasks.

Since kaons copious, potential new avenue for

radiation length studies

Supposed to have been started this term, but

code harder to understand than anticipated

no reply from B physics people who already have

kaon and pion vertex reconstruction (why

reinvent a perfectly good wheel?)

Other things learnt How to survive acronym overdose

I'm doing a PhD in HEP at UCL and RAL

Working on ATLAS at the LHC at CERN

Whilst worrying about funding from STFC,

successor to PPARC and the CCLRC

Having gotten my Grid Certificate from the UK CA, the

NGS, I've not yet affiliated myself with the ATLAS VO

Learning the meanings by a combination of colleagues,

Google and osmosis.

So far, that's one of the harder parts

I think that will be overtaken soon!