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Higgs & Top at LHeC
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CERN
CERN
Description
CERN - Tokyo - Liverpool - Johannesburg - Beijing - Hamburg
1. Satoshi Kawaguchi presented the update on H to invisible search.
A bug was found in the analysis presented on 18/July and the
2-sigma bound on branching ratio is now 7.25% (was 7.47%).
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Chen: what was the bug? - It was in dPhi calculation in cut 4.
Uta: :LHeC cards was based on CMS, which uses eflowPhotons,
but ATLAS cards uses photons container. This is the reason
ATLAS cards works with Delphes 3.1.2.
---
2. Uta showed an update of the Hbb coupling measurements using displaced vertices and TMVA analysis techniques, complementing the Hcc part shown in the 9.5.16 meeting.
An increase by factor 4 in the Hbb signal in comparison with her Chavannes 2015 results (using R=0.9 jets) could be achieved using anti-kt R=0.5 jets (around 11-15 k Hbb candidates). The Hbb analysis delivers a stable 1% Hbb coupling measurements for 1000 fb-1, i.e. 10 years running of an LHeC using a 60 GeV polarised electron beam. The results are shown to be robust w.r.t. jet selection and ATLAS run 1 and run 2 vertex resolutions.
It was also shown that anti-kt R=0.9 jets are clearly disfavoured for both Hbb and Hcc coupling measurements.
Next steps should be a publication of the results.
The Delphes card file including the correct photon containers is also attached to her presentation.
3. Hao Sun:
Anomalous FCNC Top-Higgs Couplings at the LHeC.
Hao presents (slide 6) the parametrised assumed resolutions for
Elecrons/Photons, Muons, Jets and unclustered energy.
with parameter values (e.g. for the stochastic term
for the photon energy resolution) consistent with
the ATLAS detector, however he says that the values are outdated.
Hao has obtained a new set of limit results (p.14)
He plans to post tonight an updated note on Arxiv
The plan for the future is to continue
the studies using also the DELPHES detector simulation.
4. Orhan Cakir:
FCNC single top production at a gamma p LHeC, similar as what
was presented in the LHeC CDR, p.205.
Orhan presents new studies where the following things are new:
- using the standard 60 GeV electron on 7 TeV proton scenario
(in the CDR 70 GeV were used)
- using MADGRAPH for the signal topFCNC model
- Delphes detector simulation
they show some distributions of reconstructed quantities
like the top mass peak for the signal MC.
They will continue with studying also the backgrounds
and testing how much lumi is needed for 3 sigma measurements
and for different lambda values.
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