First measurement of the top quark pair production cross section at s=13.6 TeV\sqrt{s} = 13.6 \, \mathrm{TeV} at the CMS experiment

We present the first measurement of the top quark pair production cross section at the new LHC center-of-mass energy of $\sqrt{s} = 13.6 \, \mathrm{TeV}$, using $1.20 \, \mathrm{fb}^{-1}$ of data recorded at the CMS detector. We use a new method combining dilepton and lepton+jets decay channels, constraining several experimental uncertainties in situ. A cross section of $887^{+43}_{-41}(\mathrm{stat+syst}) \pm 53 (\mathrm{lumi}) \, \mathrm{pb}$ is measured, in agreement with the standard model. This result constitutes a first validation of the new data taken by CMS in LHC Run 3.Comment: Poster at the 15th International Workshop on Top Quark Physics, Durham, UK, 4-9 September 202

News on top quark physics from the CMS experiment

An overview of several new top quark physics results from the CMS experiment at the LHC is presented. They consist of measurements of four top production, including the first observation at CMS; a precision differential measurement of ttbb production; new physics searches using an Effective Field Theory approach both in a generic multilepton tt + X final state as well as specialized for flavor-changing neutral currents and lepton flavor violation; and the first measurement of tt production at sqrt(s) = 13.6 TeV. In all cases, a brief summary of the analysis as well as the resulting numbers or limits are shown

First measurement of the top quark pair production cross section at 13.6 TeV

The first measurement of the top quark pair production cross section in proton-proton collisions at s√=13.6TeV is presented. A novel measurement technique, based on a likelihood fit to events with one or two charged leptons, is used to analyze data recorded with the CMS detector at the CERN LHC corresponding to an integrated luminosity of 1.20fb−1. The measured cross section is 887+68−67pb, in agreement with the standard model prediction

Simulation of on- and off-shell ttˉt\bar{t} production with the Monte Carlo generator bb4l at CMS

Top quark pair production processes at the LHC are important for precision measurements of observables such as the top quark mass or top quark pair spin correlations and as a background for BSM searches. As such, it is crucial that MC simulation of this process is available for experimental analyses at the highest level of precision possible. Here, we show an investigation of the NLO MC generator bb4l interfaced to Pythia 8 for parton showering. This program not only models top quark pair production, but also single top quark production in association with a W boson, as well as their interference, and correctly takes into account effects from the finite top width. We compare it to the current simulations using the hvq generator, with possible implications for future top mass measurements

News from the Top at CMS

The top quark is hypothesized in many BSM models to have enhanced, non-standard or rare interactions with other SM or BSM particles. This presentation covers the latest CMS direct results in this regard, including the tests of lepton flavor violations, baryon number violations, and the searches for rare couplings such as FCNC. This talk will also include the recent top quark studies with the data collected at the new CM energy from LHC Run-3

First measurement of the top quark pair productioncross section at s\sqrt{s}= 13.6 TeV at CMS

The top quark, as the heaviest particle in the Standard Model, is central to many of its predictions and tests of its accuracy, and can be produced in proton-proton collisions at the LHC. Starting from July this year, the CMS detector has recorded collision data at the new center-of-mass energy of 13.6 TeV in LHC Run 3. Here, we present an early look at distributions in top-antitop production events

First measurement of the ttˉt\bar{t} production cross section at 13.6 TeV

Recently, the Large Hadron Collider (LHC) at CERN reached a new, unprecedented center-of-mass energy of √s = 13.6 TeV, starting LHC Run 3. This presents the opportunity to measure relevant physical quantities at the new energy frontier, thereby checking the predictions of the standard model.In this talk, we present the first measurement of the top quark pair production cross section at √s = 13.6 TeV, using data recorded at the CMS detector. The analysis uses a new method combining dilepton and lepton+jets decay channels, constraining several experimental uncertainties such as lepton selection and b jet identification efficiencies in situ. This result also constitutes a first validation of the new data taken by CMS in LHC Run 3

Distinguishing axion-like particles and additional Higgs bosons in tt‾ \mathrm{t \overline{t}} final states at the LHC

Axion-like particles (ALPs) are gauge-singlet under the Standard Model (SM) and appear in many well-motivated extensions of the SM. Since they arise as pseudo-Nambu-Goldstone bosons of an approximate axion shift-symmetry, the masses of ALPs can naturally be much smaller than the energy scale of the underlying UV model, making them an attractive target for the Large Hadron Colloder (LHC) and the future High-Luminosity LHC (HL-LHC). In this talk, we present a method for determining the nature of a possible signal in searches for ALPs produced via gluon-fusion and decaying into top-antitop-quark ($\mathrm{t \overline{t}}$) final states in proton-proton scattering at $\sqrt{s} = 13$ TeV. Such a signal has the potential to explain a local $3.5 \sigma$ excess in resonant $\mathrm{t \overline{t}}$production at a mass scale of approximately 400 GeV, observed by the CMS collaboration in LHC Run-II data. In particular, we investigate how ALP production can be distinguished from the production of pseudoscalar Higgs bosons as they arise in models featuring a second Higgs doublet, making use of the invariant $\mathrm{t \overline{t}}$mass distribution and angular correlations sensitive tospin correlation. Furthermore, comparisons to existing experimental bounds from the LHC are presented and discussed