The CMS Detector consists of a large volume silicon tracker immersed in a high four Tesla magnetic field, together with a high resolution/granularity electromagnetic calorimeter and a nearly full solid angle coverage hadronic calorimeter. Particle flow reconstruction provides a global pp-collision event description by exploiting the combined information across all CMS sub-detectors, optimizing the reconstruction and the identification of each particle (photons, electrons, muons, unstable neutral hadrons, charged hadrons and neutral hadrons) in an event. This summary introduces the CMS particle flow algorithm, discusses the challenges associated with the LHC environment, and presents some first example results in the context of hadronic decays of taus as well as missing transverse energy.
This document gives an overview over the recent results on helicity measurement of W boson originated from top pair events. The results are obtained using data collected by the CMS detector at a center-of-mass energy of 8 TeV. The helicity measurements are confronted with the most precise theoretical predictions of the standard model.
This article presents a review of recent results on direct top quark mass measurements performed by the ATLAS and CMS collaborations on $pp$ collisions collected during Run 2 of the LHC at $\sqrt{s}=$13 TeV.
A brief review of the discovery potential of the ATLAS and CMS experiments to search for signals from extra dimensions in different luminosity scenarios is given.
New physics beyond the Standard Model could well preferentially show up at the LHC in final states with taus. The development of efficient and accurate reconstruction and identification of taus is therefore an important item in the CMS physics programme. The potentially superior performance of a particle-flow approach can help to achieve this goal with the CMS detector. Preliminary strategies are presented in this summary for the hadronic decays of the taus.
First searches for new physics phenomena using the LHC 7 TeV proton-proton collision data collected by the CMS detector in 2010 are reviewed. Results are presented of searches for new physics in events with hadronic jet pairs, and for heavy stable charged particles, including a dedicated search for long-lived particles that stop in the detector and decay in periods between beam crossings.
We present an overview of measurements of electroweak vector boson pair production and anomalous Triple Gauge Couplings (aTGC), with semileptonic and fully leptonic final states. The data analyzed were taken at center of mass energy of 7 & 8 TeV by the CMS detector at the Large Hadron Collider. The cross-section measurements are important because they are test of the Standard Model predictions, while these processes serve as background for Higgs searches and various other processes.
New heavy resonances are predicted by many extensions of the standard model of particle physics. Recent results for high mass resonance searches with the Compact Muon Solenoid detector, in the diphoton, dilepton, dijet and ttbar channels, are discussed. Limits for numerous benchmark models are presented.
The reconstruction and identification of physics objects in the CMS detector, in the context of the charged Higgs boson search analysis, are presented. The reconstruction algorithms and their performance in 7 TeV and 8 TeV LHC data are discussed. The identification of tau hadronic decays, the reconstruction of hadronic jets and missing transverse energy and the identification of b jets are described in detail.
We present results from a search for an exotic Higgs boson in the channel H$^{++}$ $\rightarrow ~\ell^{+}\ell^{+}$ with the CMS detector using data accumulated in the 2010 & 2011 running of the LHC at $\sqrt{s}$ = 7 TeV. We also present results from a search for a charged Higgs boson in $t\bar{t}$ decays in the channel H$^{+}$ $\rightarrow$ $τν$
Energetic primary cosmic rays entering the Earth's atmosphere generate flux of secondary particles including neutrinos. Muon neutrinos passed through the Earth and produced muons via the charged current reaction can be registered by experimental setups intended for the measurements with colliding beams. Due to large geometrical size and advanced muon detecting system such detectors as ATLAS and CMS on LHC have chance to contribute also into the neutrino physics. The estimation of possible rates of up-going muons produced by neutrinos is given.
The observation of inclusive diffraction with the CMS detector at the LHC is presented for centre-of-mass energies \sqrt s = 0.9 TeV and 2.36 TeV. Diffractive events are selected by the presence of a Large Rapidity Gap in the forward region of the CMS detector and uncorrected data are compared with Monte Carlo simulations based on the event generators PYTHIA and PHOJET. The measurement of the forward energy flow, in the pseudorapidity region 3.15 < |η| < 4.9, is also presented at \sqrt s = 0.9 TeV, 2.36 TeV and 7 TeV. Uncorrected data are compared with Monte Carlo simulations based on PYTHIA.
The Compact Muon Solenoid (CMS) Experiment is a general purpose particle detector experiment located at the Large Hadron Collider (LHC) at CERN. In 2008, the LHC beam was commissioned and successfully steered through the CMS detector. First results from CMS with beam data are described, focusing on detector commissioning with beam data, from beam halo studies with the endcap muon system to displays of "beam splash" events, in which the proton beam was stopped by an upstream collimator.
Forward physics with CMS at the LHC covers a wide range of physics subjects, including very low-x QCD, underlying event and multiple interactions characteristics, gamma-mediated processes, shower development at the energy scale of primary cosmic ray interactions with the atmosphere, diffraction in the presence of a hard scale and even MSSM Higgs discovery in central exclusive production. We describe the forward detector instrumentation around the CMS interaction point and present selected feasibility studies to illustrate their physics potential.
A measurement is presented of the flux ratio of positive and negative muons from cosmic ray interactions in the atmosphere, using data collected by the CMS detector at ground level and in the underground experimental cavern. The excellent performance of the CMS detector allowed detection of muons in the momentum range from 5GeV/c to 1TeV/c. For muon momenta below 100GeV/c the flux ratio is measured to be a constant 1.2766 +/-0.0032(stat.) +/-0.0032(syst.), the most precise measurement to date. At higher momenta an increase in the charge ratio is observed, in agreement with models of muon produ…
Searches for high-mass resonances decaying to pairs of standard model bosons using ATLAS and CMS detectors are presented. The searches use 15 - 36 $\textrm{fb}^{-1}$ of proton-proton collision data collected at the centre-of-mass energy of 13 TeV at the LHC. Many different final states have been considered and the results are interpreted in a range of theories beyond the standard model of particle physics, most common being heavy vector triplet and warped extra dimensions.
A prospective analysis for the search of the Standard Model Higgs boson decaying in vector boson pairs is presented with the CMS experiment in the context of the initial luminosity at the CERN LHC pp collider. Monte Carlo data corresponding to an integrated luminosity of up to 1 fb$^{-1}$ are analysed and the expected significance for a Standard Model-like Higgs boson in these channels is established.
Measurements of inclusive jet and dijet production cross sections are presented. Data from LHC proton-proton collisions at sqrt(s) = 7 TeV, corresponding to 5.0 inverse femtobarns of integrated luminosity, have been collected with the CMS detector. Jets are reconstructed up to rapidity 2.5, transverse momentum 2 TeV, and dijet invariant mass 5 TeV, using the anti-kt clustering algorithm with distance parameter R = 0.7. The measured cross sections are corrected for detector effects and compared to perturbative QCD predictions at next-to-leading order, using five sets of parton distribution func…
A search for the standard model Higgs boson in the \bbbar decay channel has been carried out with the CMS detector at the LHC collider. The searched production modes are the associated VH production, the VBF production and the production in association with top quark pairs (ttH). The analyses are based on pp collision data collected at centre-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of 5 fb$^{-1}$ and 20 fb$^{-1}$, respectively. The strategy and results of the searches are reported.
Natural SUSY suggests the existence of light stop quarks, accessible at the LHC, which are the focus of a dedicated CMS search program. I present two inclusive CMS searches that look for TeV scale colored sparticles in final states with jets, b-tagged jets and missing transverse energy performed using up to 19.4fb-1 of 8TeV LHC proton-proton data. No deviation from the Standard Model was observed in these searches, and the implications for this was shown for several simplified model scenarios and phenomenological MSSM.
This paper describes a new measurement of the flux ratio of positive and negative muons from cosmic-ray interactions in the atmosphere, using data collected by the CMS detector at ground level and in the underground experimental cavern. The excellent performance of the CMS detector allowed detection of muons in the momentum range from 3 GeV to 1 TeV. For muon momenta below 100 GeV the flux ratio is measured to be a constant $1.2766 \pm 0.0032(stat) \pm 0.0032(syst)$, the most precise measurement to date. At higher momenta an increase in the charge asymmetry is observed, in agreement with model…
Evidence is presented for standard model production of a Z boson in association with a single top quark. The analysis uses a data sample of proton-proton collisions at $\sqrt{s} = 13$ TeV recorded in 2016 by the CMS detector, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. Final states containing three leptons (electrons or muons) and at least two jets are investigated, and the measured cross section is $σ($pp $\rightarrow$ tZq $\rightarrow $Wb$\ell^{+}\ell^{-}$q) = 123$^{+44}_{-39}$ fb, where $\ell$ stands for electrons, muons or taus. The corresponding observed (expected) signif…
The flavor-changing neutral current decay B_s->mu mu is highly suppressed in the standard model, but its branching fraction of 3.4*10^-9 could be significantly enhanced through contributions from new physics. At the LHC, this rare decay could be observed for the first time. In this contribution, the prospects for measuring B_s->mu mu with the CMS detector are presented. In particular, some aspects of the experimental setup, the first and high level trigger selections, and the offline analysis are discussed.
A search for new physics in central exclusive production using the missing mass technique with the CMS detector and the CMS-TOTEM precision proton spectrometer
Results are presented for the search for invisible Higgs boson production using the full LHC dataset corresponding to integrated luminosity of 5.1 fb^-1 and 19.6 fb^-1 of proton-proton collision data at sqrt(s)= 7 TeV and 8 TeV (respectively) collected by the CMS detector. The invisible Higgs is searched for in final states of missing transverse energy, with two leptons from a recoiling Z boson. No significant excess is found beyond standard model predictions, and limits are obtained on the branching fraction of the Higgs boson to invisible particles.
The CMS experiment uses missing E_T to both measure processes in the Standard Model and test models of physics beyond the Standard Model. These proceedings show the performance of the missing E_T reconstruction evaluated by using 4.6 fb-1 of proton-proton collision data at the center-of-mass energy 7 TeV collected in 2011 with the CMS detector at the Large Hadron Collider. Missing E_T was reconstructed based on a particle-flow technique. Jet energy corrections were propagated to missing E_T. After anomalous signals and events were addressed, the missing E_T spectrum was well reproduced by MC s…
The physics reach of the CMS detector achievable with 300(0) inverse femtobarns of proton-proton collisions recorded at sqrt(s)=14 TeV is presented. Ultimate precision on measurements of Higgs boson properties, top quark physics, and electroweak processes are discussed, as well as the discovery potential for new particles beyond the standard model. In addition, the potential for future heavy ion physics is presented. This document has been submitted as a white paper to the Snowmass process, an exercise initiated by the American Physical Society's Division of Particles and Fields to assess the …
The ATLAS and CMS detectors can be used to search for heavy long-lived particles which might signal physics beyond the Standard Model. Such new states can be distinguished from Standard Model particles by exploiting their unique signatures, ranging from multi-leptons and/or jets pro- duction anywhere within the detector volume, to minimum ionizing particles with low velocity and high momentum. Here are reviewed the strategies proposed by ATLAS and CMS to search for these signals, with particular emphasis on possible challenges to the trigger and detector operations.
Many models beyond the standard model predict the existence of vector-like quarks or other types of heavy resonances. Using proton-proton collision data at center-of-mass energies of 8 and 13 TeV, the ATLAS and CMS Collaborations have performed a multitude of searches for pair and singly produced vector-like quarks decaying to W, Z, or Higgs bosons. Heavy gauge and (pseudo)scalar resonances decaying to top quarks have been searched for as well. No evidence for any of these hypothetical particles has been found yet, and stringent exclusion limits are derived on their masses, cross sections and …
We present a study of jet production in association with W and Z bosons in proton-proton collisions at a centre-of-mass energy of 7 TeV using the full 2010 data set collected by CMS corresponding to an integrated luminosity of (35.9 +/- 1.4) inverse picobarn. We report the measurement of ratios s(V + >= n jets)/s(V) and s(V + >= n jets)/s(V + >= (n - 1) jets), where V represents either a W or a Z, s stands for the cross section and n stands for the number of jets.
We present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interactions in the atmosphere, using data collected by the CMS detector both at ground level and in the underground experimental cavern at the CERN LHC. Muons were detected in the momentum range from 5 GeV/c to 1 TeV/c. The surface flux ratio is measured to be 1.2766 \pm 0.0032(stat.) \pm 0.0032 (syst.), independent of the muon momentum, below 100 GeV/c. This is the most precise measurement to date. At higher momenta the data are consistent with an increase of the charge ratio, in agreement with cosmic r…
When the LHC starts its operation, CMS will have a unique opportunity to study q uarkonium production in pp collisions and later in PbPb collisions. Here we report on the methods and plans for measuring the differential pT Jpsi->mu+mu- production cross section, using data to be collected in the first LHC run by the CMS detector. Furthermore we discuss the performance of the CMS detector for quarkonium measurements in PbPb collisions.
The CMS detector at the CERN LHC features a silicon pixel detector as its innermost subdetector. The original CMS pixel detector has been replaced with an upgraded pixel system (CMS Phase-1 pixel detector) in the extended year-end technical stop of the LHC in 2016/2017. The upgraded CMS pixel detector is designed to cope with the higher instantaneous luminosities that have been achieved by the LHC after the upgrades to the accelerator during the first long shutdown in 2013-2014. Compared to the original pixel detector, the upgraded detector has a better tracking performance and lower mass with…
After nearly two decades of design, construction and commissioning, the CMS detector was operated with colliding LHC proton beams for the first time in November 2009. Collision data were recorded at centre-of-mass energies of 0.9 and 2.36 TeV, and analyzed with a fast turn-around time by the CMS collaboration. In this talk I will present a selection of commissioning results and striking first physics resonances observed. Then I will discuss the analysis of the transverse momentum and rapidity distribution of charged hadrons, which led to the first CMS physics publication. The excellent perform…
A large fraction of the results produced by the LHC experiments during the first run were made possible by precision vertexing detectors. The all-silicon tracking detector of the CMS experiment uses a pixel detector to do vertexing. This conference report uses four physics analyses as examples where pixel detector are used to either reconstruct primary vertices, separate event tracks from pileup, and/or determine displaced vertices.
We discuss the results of searches for various new physics phenomena, including supersymmetry, in pp collisions at 7 TeV delivered by the LHC and collected with the CMS detector. These results demonstrate a good understanding of the detector and backgrounds in a variety of channels and in many cases they set the most stringent limits on these new physics phenomena, surpassing previous experiments.
The electroweak production of single-top quarks in the $t$ channel can be changed by any deviation from the standard model, it is therefore an excellent opportunity to search for new physics. In this poster the recent cross-section measurement performed by the CMS collaboration is presented with the full 2015 dataset of the LHC Run II at a center-of-mass energy of 13 TeV. The cross section and the top/antitop ratio is extracted using a binned maximum likelihood fit to the distribution of a multivariate classifier in events containing one isolated muon in the final state.
A search for the standard model Higgs boson is performed in a data sample corresponding to an integrated luminosity of 1.1 fb$^{-1}$, recorded by the CMS detector in proton-proton collisions at the LHC with a 7 TeV center-of-mass energy. The following modes are studied: W($μν$)H, W(e$ν$)H, Z($μμ$)H, Z(ee)H and Z($νν$)H, with the Higgs decaying to bb pairs. 95% C.L. upper limits on the VH production cross section are derived for a Higgs mass between 110 and 135 GeV. The expected (observed) upper limit at 115 GeV is found to be 5.7 (8.3) times the standard model expectation.
Leptons will play a key role in the first measurements performed by the LHC experiments. The ATLAS and CMS detectors are now built, and early estimates of their performances have been revisited. The expected first physics signals are described: they will shed light on the level of detector understanding and allow a control of the systematics uncertainties, opening the road to new and precision physics.
The latest measurements of the top quark mass obtained by the ATLAS and CMS experiments at the LHC for centre-of-mass energies of 7 and 8 TeV are presented. The mass of the top quark is measured using several methods and channels, including the reconstructed invariant mass distribution of the top quark and shapes of top quark decay distributions. Measurements based on the inclusive tt-bar cross section and novel observables based on the differential cross section in the tt-bar + 1 jet channel are also discussed. The results of the various channels are combined and compared to the world average…
Several theories beyond the Standard Model predict the existence of new heavy neutral bosons. Such particles could be produced in significant amounts at the LHC and their decay into a dilepton pair provides a clean signature with low background contamination. The results of the analysis of the whole 2012 dataset collected by the CMS experiment at a center of mass energy of 8 TeV are presented. No evidence for new physics is seen and upper limits on the cross section production of such particles are extracted. These results can be turned into lower limits on the mass of the heavy bosons, reachi…
With the recent discovery of the Higgs boson at the Large Hadron Collider (LHC), the goals of the Compact Muon Solenoid (CMS) experiment are now focused on probing for new physics beyond the standard model. The final state consisting of a low transverse energy photon and low missing transverse energy (MET), also called the monophoton final state, can be used to constrain a variety of extensions of the standard model, including supersymmetry. I present a search for new physics in this low MET monophoton channel using 7.3/fb of 8 TeV pp collision data collected with the CMS detector. This analys…
A search for the standard model Higgs boson in the rare mu+mu- decay channel is presented. The data samples, recorded by the CMS experiment at the LHC, correspond to integrated luminosities of 5.0 +/- 0.1 inverse femtobarns at 7 TeV center-of-mass energy and of 19.7 +/- 0.5 inverse femtobarns at 8 TeV. To enhance the Higgs signal over the dominant Drell-Yan background, the events are categorized by topologies corresponding to different production processes. Upper limits on the production rate, with respect to the Standard Model prediction, are reported at the 95% confidence level for Higgs bos…
A search for a heavy Higgs boson in the $H\rightarrow ZZ\rightarrow 2\ell2ν$ decay channel, where $\ell$ = e or $μ$, in pp collisions at a centre-of-mass energy of 7 and 8 TeV is presented. The search is optimized separately for the vector boson fusion and the gluon fusion production processes. No significant excess is observed above the background expectation. A re-interpretation of the results as a search for an electroweak singlet extension of the Standard Model is also presented.
In the upcoming years, with the upgrade of the LHC to higher luminosities, CMS will be subject to an increasing flux of particles, especially in its most forward region, at | η| > 1.6. To consolidate the muon spectrometer of CMS and increase redundancy, the CMS GEM collaboration proposes to instrument the 1.6 < | η| < 2.1 region, originally foreseen to be equipped with RPC, with Triple-GEM detectors. This technology has proven to remain efficient under high fluxes and meets the requirements of CMS. This work, using simulations, studies three track reconstruction algorithms intended to be insta…
Measurements of normalized differential top-quark-pair ($t\bar{t}$) production cross sections are performed using final states with two leptons ($e^+e^-$, $μ^+μ^-$, and $e^\pmμ^\mp$) in proton-proton ($pp$) collisions at $\sqrt{s}$ = 13 TeV at the CERN LHC. The data were recorded in 2015 with the CMS detector and correspond to an integrated luminosity of 2.2 fb$^{-1}$. The $t\bar{t}$ production cross section is measured as a function of kinematic properties of the top quarks and the $t\bar{t}$ system in the full phase space, as well as of the jet multiplicity in the event in the fiducial phase…
The possibility of separating the $π^0, η, ω$ and $K^0_s$ meson background from the signal photons produced directly in $pp$ collisions is analyzed. The rejection factors for two pseudorapidity regions 0.4<η<1.0$ and 1.6<η<2.0$ and six Et values, 20, 40, 60, 80, 100 and 200 GeV, are calculated for a case when only the calorimeter information is used. The cases of $η, ω$ and $K^0_s$ mesons decaying through the neutral and charged channels are considered separately.
In the framework of the High Luminosity LHC upgrade program, the CMS muon group built several different RPC prototypes that are now under test at the new CERN Gamma Irradiation Facility (GIF++). A dedicated Detector Control System has been developed using the WinCC-OA tool to control and monitor these prototype detectors and to store the measured parameters data. Preliminary efficiency studies that set the base performance measurements of CMS RPC for starting aging studies are also presented.
The CMS inner pixel detector system is planned to be replaced during the first phase of the LHC luminosity upgrade. The plans foresee an ultra low mass system with four barrel layers and three disks on either end. With the expected increase in particle rates, the electronic readout chain will be changed for fast digital signals. An overview of the envisaged design options for the upgraded CMS pixel detector is given, as well as estimates of the tracking and vertexing performance.
We have created 3D models of the CMS detector and particle collision events in SketchUp, a 3D modelling program. SketchUp provides a Ruby API which we use to interface with the CMS Detector Description to create 3D models of the CMS detector. With the Ruby API, we also have created an interface to the JSON-based event format used for the iSpy event display to create 3D models of CMS events. These models have many applications related to 3D representation of the CMS detector and events. Figures produced based on these models were used in conference presentations, journal publications, technical…
Recent results on heavy flavor physics using data from the ATLAS and CMS detectors are presented. The searches for new physics signatures in CP violation of B0_s - anti(B0_s) mixing and in B0_d --> K*0 mu+ mu- decays are discussed. The bottomonium and open-b production results obtained from proton-proton collisions at LHC are shown. The results are based on data samples containing mu+ mu- pairs collected with the ATLAS or CMS detectors by their corresponding muon trigger systems.
In the first LHC running period the CMS-pixel detector had to face various operational challenges and had to adapt to the rapidly changing beam conditions. In order to maximize the physics potential and the quality of the data, online and offline calibrations were performed on a regular basis. The detector performed excellently with an average hit efficiency above 99% for all layers and disks. In this contribution the operational challenges of the silicon pixel detector in the first LHC run and the current long shutdown are summarized and the expectations for 2015 are discussed.
A clear evidence of inclusive diffraction observed by the CMS detector at the Large Hadron Collider in minimum bias events at $\sqrt{s}=$0.9 TeV, 2.36 TeV is presented. The observed diffractive signal is dominated by inclusive single-diffractive dissociation and can be identified by the presence of a Large Rapidity Gap that extends over the forward region of the CMS detector. A comparison of the data with Monte Carlo predictions provided by PYTHIA6 and PHOJET generators is given. In addition, first observation of the single-diffractive production of di-jets at $\sqrt{s}=$7 TeV is presented.
A search for narrow resonances at high mass in the dimuon and dielectron channels has been performed by the CMS experiment at the CERN LHC, using pp collision data recorded at sqrt{s}=7 TeV. The event samples correspond to an integrated luminosity of 1.1 fb^{-1}. Heavy dilepton resonances are predicted in theoretical models with extra gauge bosons (Z') or as Kaluza-Klein graviton excitations (G_{KK}) in the Randall-Sundrum model. Upper limits on the inclusive cross section of Z'(G_{KK}) to l+l- relative to Z to l+l- are presented. These limits exclude at 95 % confidence level a Z' with standar…
The two calorimeters CASTOR and ZDCs enhance the hermeticity of the CMS detector at the LHC by extending the rapidity coverage in the forward region. After having described these detectors, their forward physics capabilities are presented. These latters include the study of parton shower, multiple parton interactions, diffraction and ultra high energy cosmic rays models. The processes to be measured to constrain these topics are multi-jet events with a forward jet, central-forward activity correlation, rapidity gaps and forward neutron production.
Triple-GEM detectors for the GE2/1 and ME0 stations of the endcap muon system for the Phase-2 upgrade of the CMS Experiment have been operated in a test beam to measure their efficiency and spatial resolution, together with a high spatial resolution triple- GEM tracker. A production module of GE2/1 detectors and a prototype ME0 detector show excellent local efficiency. A prototype detector with GEM foils employing random hole sectorization showed significant reduction of dead areas. The spatial resolution of the tracker has been measured and found close to the expected value of 75 μm.
The latest results on searches for production of two Higgs bosons with the CMS detector using the 2016 CERN LHC dataset are presented, as shown at the LHCP 2017 conference.
We report on a precision measurement of the effective weak mixing angle using the forward-backward asymmetry of Drell-Yan ($ee$ and $μμ$) events in pp collisions at $\sqrt{s}=8~\mathrm{TeV}$ at CMS. The data sample corresponds to an integrated luminosity of $18.8~\mathrm{fb}^{-1}$ and $19.6~\mathrm{fb}^{-1}$ for muon and electron channels, respectively. The sample consists of 8.2 million dimuon and 4.9 million dielectron events. With new analysis techniques and large samples the statistical and systematic uncertainties are reduced by a factor of two compared to previous measurements at the LHC…
We present the first results on searches for new massive resonances decaying to a top-antitop quark ($t\bar{t}$) pair with the CMS detector at the LHC in proton-proton collisions with a center of mass energy of $\sqrt{s}=13~\mathrm{TeV}$. The data set considered corresponds to an integrated luminosity of $2.6~\mathrm{fb}^{-1}$ recorded during the the first year of the LHC Run-2. Searches are performed by measuring the invariant mass distribution of the $t\bar{t}$ system in semileptonic and fully-hadronic final states. Dedicated techniques are used to identify the decay of highly-boosted top qu…
