Contact
Name
Georgios Konstantinos Krintiras

Position
Former member
Member from February 2015 to January 2019

Personal homepage
Oral Presentations
First measurement of the t-channel single top-quark cross section with CMS at √s = 13 TeV
Measurement of the associated Higgs production with single top-quarks in the t-channel with CMS at √s = 13 TeV
Top quark pair production cross section measurements with CMS
Measurement of the associated Higgs production with top quarks in CMS at √s = 13 TeV
Study of top production in complementary phase space regions and impact on PDFs in CMS
Observation of top quark production in proton-nucleus collisions
Results on Top physics from CMS
Observation of top quark production in proton-nucleus collisions
Measurements of top properties and couplings at the LHC
Observation of top quark production in proton-nucleus collisions
Heavy ions at the LHC - overview
Heavy ions at the LHC - overview
Public thesis defence/défense publique de thèse
Poster Presentations
Constraining QCD multijet background in the t-channel single top-quark production at √s = 13 TeV
Measurement of the top quark pair production cross section using dilepton events at √s = 5.02 TeV
Luminosity calibration at √s = 5.02 TeV
Luminosity calibration at √s = 5.02 TeV
Observation of top quark production in proton-nucleus collisions
Observation of top quark production in proton-nucleus collisions
Seminar Presentations
Measurement of the top quark pair production cross section and luminosity calibration at √s = 5.02 TeV
Top quark production in nuclear collisions
Projects
Research directions:
Experiments and collaborations:
Active projects
Fast Simulation of the CMS experiment
Andrea Giammanco

A framework for Fast Simulation of particle interactions in the CMS detector (FastSim) has been developed and implemented in the overall simulation, reconstruction and analysis framework of CMS. It produces data samples in the same format as the one used by the Geant4-based (henceforth Full) Simulation and Reconstruction chain; the output of the Fast Simulation of CMS can therefore be used in the analysis in the same way as data and Full Simulation samples. FastSim is used in several physics analyses in CMS, in particular those requiring a generation of many samples to scan an extended parameter space of the physics model (e.g. SUSY) or for the purpose of estimating systematic uncertainties. It is also used by several groups to design future sub-detectors for the Phase-II CMS upgrades.
Related activities at UCL include the integration with the Full Simulation in the simulation of the electronic read-out ("digitization") and of the pileup of events from other proton-proton collisions, both in-time and out-of-time; the performance monitoring; and the overall maintenance and upgrade of the tracking-related code. Matthias Komm is current L3 convener of Tracking in FastSim, and Andrea Giammanco has been main responsible of the FastSim project from 2011 to 2013.
Luminosity calibration of the CMS detector
Andrea Giammanco

We contribute to the offline absolute calibration of the luminometry system of the CMS detector, by analysing the dedicated "Van der Meer scan" data at different center-of-mass energies and collision types (p-p, p-Pb, Pb-Pb).

As a related task, we also contribute to the data-driven inference of the true amount of "pile-up" collisions.

External collaborators: CMS Luminosity Physics Object Group.
Single top studies at LHC
Andrea Giammanco

The electroweak production cross section of single top quarks is an important measurement for LHC, being a potential window on "new physics" effects.
Past achievements of this group include the very first measurement at 7 TeV (in t channel) with 2010 data, followed by the most precise inclusive cross section measurements of t-channel cross section at 7, 8 and 13 TeV, and the first differential measurements at 13 TeV; the most precise |Vtb| extraction from single top in the world; the first measurement of W-helicity fractions in a single-top topology; the first observation of the tW production mode; the first measurement of single-top polarization in t channel; stringent limits on anomalous tWb, tgu, tgc couplings.

External collaborators: CMS collaboration.
Testing the sign of the coupling of the new H(125) boson to top quarks with the CMS data
Andrea Giammanco

During 2012, the CMS and ATLAS collaborations independently reported unambiguous evidence of the existence of a new particle of mass around 125 GeV.
Several analyses are ongoing to challenge the hypothesis that the new particle is the SM Higgs. We focus on the search for its production in association with a single top quark. Due to an effect of quantum interference, this process is strongly suppressed in the Standard Model while it gets enhanced if its couplings to the top quark and to the W boson have opposite sign. An observation of this production mode would therefore be a convincing proof that this new particle does not belong to the Standard Model.
We published the first search for this process using 8 TeV data, and we expect to achieve sensitivity to anomalous values of the top Yukawa phase during the LHC Run-II.

External collaborators: CMS collaboration.
Top quarks in Heavy Ion collisions and other non-standard LHC datasets
Andrea Giammanco

The top quark, being the heaviest known elementary particle, is a powerful tool to test QCD.
The study of top quark pair production in Heavy Ion collisions at the LHC, making use of the dedicated Pb-Pb and p-Pb runs, will open a new road in the investigation of the Quark-Gluon Plasma.

This research project started with the first measurement of top-pair cross section in pp collisions at 5.02 TeV, taking advantage of a "reference run" in Nov.2015. This measurement, in addition to being useful as a reference for measurements in Pb-Pb and p-Pb collisions at the same center-of-mass energy per nucleon, also provides a significant broadening of the lever arm for global PDF fits making use of top-quark data.

More recently we reported the first observation of top quark production in p-Pb collisions, using the data at 8.16 TeV taken in Nov.2016, testing the models of nuclear modification of the gluon PDF at high Bjorken-x.

We are now preparing future analyses in PbPb collisions. We are also interested in differential analyses in pPb collisions (to constrain nuclear PDFs) and in searches in central exclusive production pp events.

External collaborators: David D'Enterria, Pedro Silva and Marta Verweij (CERN).
Publications in CP3
All my publications on Inspire

Number of publications as CP3 member: 24

Last 5 publications

2018

CP3-18-80: New physics searches with heavy-ion collisions at the LHC
Bruce, Roderik and others

[Abstract] [PDF]
17 pages, 4 figures. A slightly reduced version of this document has been submitted as input to the update of the European Particle Physics Strategy (EPPS)
Refereed paper. December 20.
CP3-18-75: Constraining nuclear parton distributions with heavy ion collisions at the HL-LHC with the CMS experiment
CMS Collaboration

[Full text]
Physics Analysis Note CMS-PAS-FTR-18-027, Used as Input to the Yellow Report 2018 on the HL-LHC and HE-LHC
December 17.
CP3-18-74: Future physics opportunities for high-density QCD at the LHC with heavy-ion and proton beams
Working Group 5 (HL-LHC, HE-LHC)

[Abstract] [PDF] [Full text]
Yellow Report from Working Group 5 on the Physics of the HL-LHC, and Perspectives at the HE-LHC, to be posted to the European Strategy Group
December 15.
CP3-18-67: Search for associated production of a Higgs boson and a single top quark in proton-proton collisions at $\sqrt{s} =$ 13 TeV
Sirunyan, Albert M and others

[Abstract] [PDF] [Journal] [Dial]
Published in PRD (DOI: 10.1103/PhysRevD.99.092005 )
Refereed paper. November 27.
CP3-18-44: Search for the associated production of a Higgs boson and a single top quark in pp collisions at sqrt(s)=13 TeV
CMS Collaboration

[Full text]
Physics Analysis Summary HIG-18-009, Presented at the XXXIX International Conference on High Energy Physics, ICHEP 2018, Seoul, South Korea, 4-11 July, 2018
Public experimental note. July 6.

More publications
Further Material
Miscellaneous
CMS Create #2
Présentations pour la Voyage au CERN 2017
CMS official guide (contact me ;D)