Final Report Summary - LHC-TOOLS-PHYS (Tools for the Large Hadron Collider - from the Lagrangian to the experimental analysis)
On July 4th CERN has announced the discovery of a scalar particle at the Large Hadron Collider (LHC), later identified as a Higgs boson. This scientific breakthrough was accomplished due to the joint efforts of thousands of scientists from all around the globe. This long awaited discovery increased our understanding of the world, providing an explanation for the mechanism through which all elementary particles acquire mass. However, there are still fundamental questions awaiting a clear answer, which require the construction of new theoretical models, above and beyond the current prevalent description of fundamental phenomena, and, inevitably, their experimental confirmation or disproval. In this project we have concentrated on scenarios which see the presence of more than one Higgs boson. We have discussed the main features of these models and we have studied their phenomenology at the LHC using precision measurements as well as by exploiting Higgs-to-Higgs signatures or into new matter states, both unavailable in the minimal scenario.
We have exposed our hypotheses to full scrutiny by the particle physics community by making our finding available in published refereed papers and also in the form of automated computing tools. We have developed a public available tool, ScannerS, that automatically finds minima of the extended scalar potential. We have shown that these extensions are not excluded (in some scenarios they can even provide a better fit to LHC data) and have pointed out new directions to probe them. We wrote two major reviews on one of the most popular extensions of the SM - the two-Higgs doublet model. We have also applied our expertise in Higgs physics and discrete and symmetries to neutrino oscillation.
The second part of the project was related to the top quark. The top is the least known of all quarks and the ideal place to look for new physics. In fact, unlike all other quarks the top decays before hadronisation occurs. A huge number of tops per year are produced ate the LHC. A detailed study of the top quark will definitely reveal if the top-quark is just like the other quarks but with a larger mass or if it hides something. We have concluded an event generator for the LHC, named MEtop. There was a previous thorough theoretical study of flavour changing neutral currents involving top quarks. The generator is now an official generator for the ATLAS collaboration at the LHC. We have used this generation to point some directions to improve the analysis of direct top production.
Finally, in more global terms, I believe the project has had some impact on the research areas of Higgs and top-quark physics with a very positive outcome for scientific society as a whole, in line with the Work Programme within which the grant was developed.
We have exposed our hypotheses to full scrutiny by the particle physics community by making our finding available in published refereed papers and also in the form of automated computing tools. We have developed a public available tool, ScannerS, that automatically finds minima of the extended scalar potential. We have shown that these extensions are not excluded (in some scenarios they can even provide a better fit to LHC data) and have pointed out new directions to probe them. We wrote two major reviews on one of the most popular extensions of the SM - the two-Higgs doublet model. We have also applied our expertise in Higgs physics and discrete and symmetries to neutrino oscillation.
The second part of the project was related to the top quark. The top is the least known of all quarks and the ideal place to look for new physics. In fact, unlike all other quarks the top decays before hadronisation occurs. A huge number of tops per year are produced ate the LHC. A detailed study of the top quark will definitely reveal if the top-quark is just like the other quarks but with a larger mass or if it hides something. We have concluded an event generator for the LHC, named MEtop. There was a previous thorough theoretical study of flavour changing neutral currents involving top quarks. The generator is now an official generator for the ATLAS collaboration at the LHC. We have used this generation to point some directions to improve the analysis of direct top production.
Finally, in more global terms, I believe the project has had some impact on the research areas of Higgs and top-quark physics with a very positive outcome for scientific society as a whole, in line with the Work Programme within which the grant was developed.