Marumi Kado started his talk by saying he will only present new results based on the full 2015 13 TeV pp collision dataset.
For Run 2 there have been a large number of improvements to the detector.
Also the trigger has been improved, with a new central trigger processor. Reconstruction software also was improved significantly.
Marumi spent a long time describing the retuning of the detector and the performance in reconstruction of impact parameters, physics objects, and the like. The physics modellinghas been verified in several control samples of dibosons, top pairs, etcetera.
Marumi shows that the Higgs signals in ATLAS are wanting. 0.7 sigma observed in 4-lepton mode, expected 2.8 sigma. Similar story in diphotons.
High-mass searches for 4-lepton higgs-like events reveal some fluke at 500 GeV, "absolutely not significant" according to Marumi once one accounts for the look-elsewhere effect.
As the cross section ehnancement for a 1.5 TeV gluino in going from 8 to 13 TeV is x35, there is interest in looking for that signal. But neither ATLAS sees a signal, to 1.5 TeV.
ATLAS continues to see an excess in the Z+MET SUSY signature, 21 events observed against 10.4 expected. This is interesting, as it is consistent with the 3-sigma excess they had found in 8 TeV data.
Highest dilepton masses observed by ATLAS are below 2 TeV... CMS does better with a 2.7 dielectron event
The diphoton excess seen by ATLAS is a 3.6 sigma effect, but once one accounts for the trials factor it is a 1.9 sigma effect. The mass distribution is shown below.
New ATLAS Results From The 13 TeV LHC Jamboree
By Tommaso Dorigo | December 15th 2015 06:55 AM | Print | E-mail