PH4100 Major Project (for projects before 2010)

WW / total 60k 20k Mar 11 2009 fastsim_WW_r8156_ntp.root 20k Mar 11 2009 fastsim_WW_r8158_ntp.root 20k Mar 11 2009 fastsim_WW_r8160_ntp.root

ZW / total 40 k 20k Mar 11 2009 fastsim_ZW_r8254_ntp.root 20k Mar 11 2009 fastsim_ZW_r8256_ntp.root

ZZ / total 40 k 20k Mar 11 2009 fastsim_ZZ_r8354_ntp.root 20k Mar 11 2009 fastsim_ZZ_r8356_ntp.root

In preparation (11/3/09).

Important Note: the PYTHIA cross-section for tt is LO only, and there are significant higher order corrections; to account for these, use a cross-section of 830 pb instead.

Higgs production cross-sections and branching ratios for the ATLAS Higgs working group, ATL-COM-PHYS-2007-024

Analysing the data

ROOT

The actual data analysis code will be written by the student, in C++. I will provide you with template code to read in an ntuple, book some histograms, apply some event selection cuts, fill in the histograms and print them to file. (Files run_analysis.C, analysis.C and analysis.h)

Introduction

The student is advised to read about the LHC, its physics programme, and past and ongoing searches for the Higgs boson. Select some papers from this list of overview papers.

The fractions of signal and background events that will contribute to a particular final state (eg, tt-->bqq blv) should be calculated using this table of Branching Ratios (BR) (from PYTHIA 6.323). It contains useful data on the BRs of Higgs, W and Z bosons, tau leptons, and more.

ATLFAST ntuples

More information: the ATLFAST simulation program; content of the ntuples.

PH4100 Major Project

Information regarding 4th year projects based on ATLFAST ntuples. See my Log Book 11, page 10, for useful notes fo rthe project kick-off meetings.

ATLFAST 11.0.5 ntuples

Information on the simulated samples can be found in my Log Book 11, page 23. All of the samples below include simulation of the underlying event. PYTHIA 6.323 was used to generate the events. The cross-sections quoted below are those provided by PYTHIA (except where explicitly stated otherwise). (See page 36 of Log Book 11 for more details.) The fast simulation ntuples include Run No and Event No information.

Background samples

The following background samples can be found in linappserv1:/scratch0/ptd/ATLAS/EVTutorial/ReGenWithUE/

1 ls -al *ntp* | grep fastsim | grep _tt_ / total 80k events / PYTHIA sigma = 494.5 pb (but use 800 pb ? instead)
20k Jan  6  2007 fastsim_tt_r8050_ntp.root
20k Jan  7  2007 fastsim_tt_r8052_ntp.root
20k Jan  7  2007 fastsim_tt_r8054_ntp.root
20k Jan  7  2007 fastsim_tt_r8056_ntp.root
 1 ls -al *ntp* | grep fastsim | grep _WW_ / total 70k events / PYTHIA sigma = 70.9 pb 
30k Jan  6  2007 fastsim_WW_r8150_ntp.root
20k Jan  7  2007 fastsim_WW_r8152_ntp.root
20k Jan  7  2007 fastsim_WW_r8154_ntp.root
 1 ls -al *ntp* | grep fastsim | grep _ZW_ / total 50k events / PYTHIA sigma = 27.0 pb
30k Jan  7  2007 fastsim_ZW_r8250_ntp.root
20k Jan  8  2007 fastsim_ZW_r8252_ntp.root
 1 ls -al *ntp* | grep fastsim | grep _ZZ_ / total 50k events / PYTHIA sigma = 11.2 pb
30k Jan  5  2007 fastsim_ZZ_r8350_ntp.root
20k Jan  8  2007 fastsim_ZZ_r8352_ntp.root

Signal samples

The following signal sample (generted in 2007) can be found in linappserv1:/scratch0/ptd/ATLAS/EVTutorial/ReGenWithUE/

fastsim_GFhWW_m120_r2050_ntp.root / total 20k events / PYTHIA sigma = 2.53 pb

The following signal samples, generated in Oct 2008, are available in linappserv1:/scratch2/ptd/ATLAS/MCsamples/2008/ATLFAST

The following table gives details of all the signal samples