Reports from the Mass 2011 LHC Training School

May 27, 2011

Share this pageShare on FacebookTweet about this on TwitterShare on LinkedInGoogle+

The Mass 2011 LHC Training School was held May 9-13, 2011. The students were divided into three groups each looking at different Beyond the Standard Model theories and event generator tools needed to make sensible predictions for the LHC experiments, such as MadGraph and CalcHEP.

As part of the final evaluation each group had to turn in a small report discussing their results.

Discovering SUSY

Link to PDF.

The main purpose of our work was obtaining the data to compare with the results of the CMS paper arXiv:1101.1628v2. We were looking for the processes where one can find the trace of SUSY particle neutralino. Quantum numbers of neutralino allows it to be an appropriate dark matter particle candidate. So, our first aim was to choose the parameters of the theory we were working within so that neutralino could be found in the final state of some process. We chose the so-called CMSSM framework where we have fixed 3 of 5 parameters (tan β = 3, A0 = 0, μ > 0). After that step one can plot all possible theories on the (m0,m1/2) plane.

Discovering Technicolor

Link to PDF.

We provide a pedagogical introduction to a popular extension of the Standard Model (SM), the Minimal Walking Technicolor (MWT), in which the Higgs is com- posite. We therefore introduce the SM particle spectrum, review very briefly the electroweak dynamical symmetry breaking mechanism, and present the MWT salient features. After a brief review of collider physics and introduction to the Madgraph event generator, we finally present relevant MWT signatures at LHC.

Discovering the 4th Generation

Link to PDF.

In this report we have studied the signatures of an additional fourth generation of heavy leptons and how they would look like at the LHC. In order to study this we used the CalcHEP program where we added new particles and interactions according to predictions from theory. In order to validate our implementations we cross checked the output from CalcHEP with analytical expressions of decay width. Further we looked at final states with same sign leptons together with jets. These are interesting final states for searches at the LHC since same sign dilepton production in the Standard Model is believed to be very small. Finally we used a full 4th generation model within the Minimal Walking Technicolor framework and looked at some interesting signals which could serve as good candles in order to discover such kind of models at a hadron collider. If models, like the one we have studied here, are realized in nature, LHC will be able to discover them or at least set hard limits on the masses and couplings.