[Rivet] Analysis on "tth" and "tH" LHC

[Andy Buckley]

On 09/10/15 18:45, Mukesh Kumar wrote:
> Dear Rivet analyses Team,
>
> I am new to Rivet and try to learn this analysis package with several examples and codes available.
> I was wondering if you people have done some analyses on associated top pair and single-top with
> Higgs in different decay modes of top and Higgs at LHC with 7/8 TeV !!
> Since I was looking at the source code list but didn’t find anywhere.

Hi Mukesh,

There are top analyses written in Rivet, notably the ATLAS_2015_I1345452 
pseudo-top cross-sections analysis.

There are also ATLAS_2013_I1243871 and ATLAS_2014_I1304688 which measure 
jet properties in top events.

Decaying tops is pretty much the most complicated common system in 
collider physics, and there is no unambiguous best way to define tops 
from final-state objects -- hence we don't have a built-in push-button 
TopFinder object. The choice of best reconstruction depends on what the 
analysis is looking at: which decay channels, which variables?

The first of the analyses I listed above is explicitly a measurement of 
reconstructed combinations of leptons, MET, and (b-tagged) jets which is 
considered as an operation definition of a "top", without unfolding to 
parton level. The others do not (I think) explicitly reconstruct the 
top(s) at all, but are based on background-subtracted events corrected 
to parton-level top selection, and assume that only top events will be 
run through the analysis. This is also fine, provided the data covers 
the unfolding uncertainties well.

For your analysis... you can do whatever you like. If you let us know 
what you have in mind, we can give advice.

Best wishes,
Andy

-- 
Dr Andy Buckley, Lecturer / Royal Society University Research Fellow
Particle Physics Expt Group, University of Glasgow