In the last two weeks the approvals activity continued to increase heading to QM2014 and LHCP conferences.

In the searches area we had the review of one of the first analysis using b tagging in boosted topologies. B2G-14-002 presents a search for heavy resonances decaying to top quarks and Higgs bosons in all-hadronic final states. The benchmark model is pair-produced vector- like T’ quarks with charge 2/3. The boosted topology comes from the assumption of high masses of the T’. Assuming an exclusive branching ratio BR(T’→ tH) = 100%, the observed (expected) lower limit on the mass of the T’ is 756 GeV (770 GeV).

In the dark matter arena we had the approval of the analysis using the typical monophoton signature with 8 TeV data (EXO-12-047). No deviation from the Standard Model prediction is observed allowing to extend the current limits on several models : in the ADD framework modified Planck scales below 2.0/2.3 TeV for 3-6 extra dimensions are excluded at 95%CL, WIMP-hadron cross section limits range between 8 and 5 fb at 90%CL for masses between 1 GeV and 1 TeV. For the first time we have also an extensive set of limits on branon’s phenomenology.

A search for contact interactions (EXO-12-020) has also been completed using events with muon or electron pairs collected at 8 TeV. Within the context of a quark and lepton compositeness model with a left-left isoscalar contact interaction, 95% CL lower limits are set on Λ, the energy scale parameter for the contact interaction. These limits are between 12.0 and 18.3 TeV depending on channel and assumptions on the interference with SM Drell-Yan production.

In the Standard Model group we have approved a study of topological distributions of three- and four-jet events collected at 7 TeV (QCD-11-006). They serve as a natural probe of quantum chromodynamics. Comparisons are carried out with the data and predictions of leading order calculations and parton shower generators.

The Heavy Ion group is completing the program for QM2014. We had four approvals in the last two weeks: HIN-14-016 contains an analysis of jet-track correlations in PbPb collisions, HIN-14-008 shows a new method to study the delta-eta dependence of the ridge structure by decomposing di-hadron correlations into a genuine “ridge” component and the jet component. W boson and B meson production in pPb collision are also studied in HIN-13-007 and HIN-14-004, respectively.

In other news:

  • The final reading of the Higgs width analysis has taken place and the paper was eventually submitted to PLB on May 14th.
  • The pre-approval of the Higgs combination analysis where all of the legacy paper inputs will be used had taken place on May 14th.
  • The current goal, still under discussion, is to produce a PAS in time for the Summer conferences replacing the by now obsolete HIG-13-005 dating back to Moriond 2013.


    • Our next PH-LHC seminar (May 20th: )) will be given by Marco Zanetti on luminosity determination and precision cross section measurements at CMS. A rehearsal for the seminar is foreseen on Monday May 19th: .

    Our next slot is foreseen for July 15th. Everybody is invited to provide their topic suggestion in CINCO: https://cms-mgt-conferences.web.cern.ch/cms-mgt-conferences/conferences….

    by Luca Malgeri

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