Showing 3 of 3 results
This Letter reports the observation of single top quarks produced together with a photon, which directly probes the electroweak coupling of the top quark. The analysis uses 139 fb$^{-1}$ of 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. Requiring a photon with transverse momentum larger than 20 GeV and within the detector acceptance, the fiducial cross section is measured to be 688 $\pm$ 23 (stat.) $^{+75}_{-71}$ (syst.) fb, to be compared with the standard model prediction of 515 $^{+36}_{-42}$ fb at next-to-leading order in QCD.
This table shows the values for $\sigma_{tq\gamma}\times\mathcal{B}(t\rightarrow l\nu b)$ and $\sigma_{tq\gamma}\times\mathcal{B}(t\rightarrow l\nu b)+\sigma_{t(\rightarrow l\nu b\gamma)q}$ obtained by a profile-likelihood fit in the fiducial parton-level phase space (defined in Table 1) and particle-level phase space (defined in Table 2), respectively.
Distribution of the reconstructed top-quark mass in the $W\gamma\,$CR before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions. The first and last bins include the underflow and overflow, respectively.
Distribution of the NN output in the 0fj$\,$SR in data and the expected contribution of the signal and background processes after the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions considering the correlations of the uncertainties as obtained by the fit.
Distribution of the NN output in the $\geq$1fj$\,$SR in data and the expected contribution of the signal and background processes after the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions considering the correlations of the uncertainties as obtained by the fit.
Distribution of the NN output in the $t\bar{t}\gamma\,$CR in data and the expected contribution of the signal and background processes after the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions considering the correlations of the uncertainties as obtained by the fit.
Total event yield in the $W\gamma\,$CR in data and the expected contribution of the signal and background processes after the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions considering the correlations of the uncertainties as obtained by the fit.
Distribution of the scalar sum of the jet transverse momenta in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions. The first and last bins include the underflow and overflow, respectively.
Distribution of the $\eta$ of the $b$-tagged jet in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions.
Distribution of the reconstructed top-quark mass in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions. The first and last bins include the underflow and overflow, respectively.
Distribution of the $p_{\mathrm{T}}$ of the top-quark+photon system in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.
Distribution of the photon $p_{\mathrm{T}}$ in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.
Distribution of the photon $\eta$ in the 0fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions.
Distribution of the scalar sum of the jet transverse momenta in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.
Distribution of the invariant mass of the $b$-tagged jet and the highest-$p_{\mathrm{T}}$ forward jet in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.
Distribution of $p_{\mathrm{T}}$ of the highest-$p_{\mathrm{T}}$ forward jet in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.
Distribution of the difference in $\eta$ between the highest-$p_{\mathrm{T}}$ forward jet and the photon in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.
Distribution of the energy of the system formed by the highest-$p_{\mathrm{T}}$ forward jet and the photon in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions. The first and last bins include the underflow and overflow, respectively.
Distribution of the $\eta$ of the $b$-tagged jet in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions.
Distribution of the reconstructed top-quark mass in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions. The first and last bins include the underflow and overflow, respectively.
Distribution of the $p_{\mathrm{T}}$ of the top-quark and photon system in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.
Distribution of the photon $p_{\mathrm{T}}$ in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions and the last bin includes the overflow.
Distribution of the photon $\eta$ in the $\geq$1fj$\,$SR in data and for the sum of all processes expectations before the profile-likelihood fit. The "Total" column corresponds to the sum of the expected contributions from the signal and background processes. The uncertainty represents the sum of statistical and systematic uncertainties in the signal and background predictions.
Ordered list of the 30 systematic uncertainties with the largest impact on the measured signal normalisation in the fit to data in the parton-level measurement considered as nuisance parameters (NPs) in the profile-likelihood fit. The column "NP value, error" corresponds to the nominal best-fit values and the corresponding uncertainties. The impact of each NP, $\Delta\sigma$/$\sigma_{\mathrm{pred}}$, is computed by comparing the nominal best-fit value of the POI ($\sigma$/$\sigma_{\mathrm{pred}}$) with the result of the fits when fixing the considered NP to its best-fit value shifted by its pre-fit and post-fit uncertainties. The corresponding impacts are listed in the "POI impact prefit high/low" and "POI impact high/low" columns, respectively. The "MC stat." NPs represent the MC statistical uncertainty and they enter the likelihood with a Poisson term, while all the other NPs enter the likelihood via a Gaussian term.
Ordered list of the 30 systematic uncertainties with the largest impact on the measured signal normalisation in the fit to data in the particle-level measurement considered as nuisance parameters (NPs) in the profile-likelihood fit. The column "NP value, error" corresponds to the nominal best-fit values and the corresponding uncertainties. The impact of each NP, $\Delta\sigma$/$\sigma_{\mathrm{pred}}$, is computed by comparing the nominal best-fit value of the POI ($\sigma$/$\sigma_{\mathrm{pred}}$) with the result of the fits when fixing the considered NP to its best-fit value shifted by its pre-fit and post-fit uncertainties. The corresponding impacts are listed in the "POI impact prefit high/low" and "POI impact high/low" columns, respectively. The "MC stat." NPs represent the MC statistical uncertainty and they enter the likelihood with a Poisson term, while all the other NPs enter the likelihood via a Gaussian term.
This table lists the kinematic requirements on parton-level objects used to define of the fiducial phase space for the parton-level measurement. Frixione isolation ($\href{https://arxiv.org/abs/hep-ph/9801442}{\text{hep-ph/9801442}}$) with a chosen radius of $\Delta R = 0.2$ is applied to photons ($\gamma$). The measured fiducial parton-level cross section is $\sigma_{tq\gamma}\times\mathcal{B}(t\rightarrow l\nu b) = 688\pm 23(\text{stat.})^{+75}_{-71}(\text{syst.})\,$fb.
This table lists the kinematic requirements on particle-level objects used to define of the fiducial phase space for the particle-level measurement. The particle level objects are photons ($\gamma$) not from a hadron decay, neutrinos not from a hadron decay ($\nu$), prompt electrons and muons ($\ell$) "dressed" by adding close-by ($\Delta R < 0.1$) photons, and anti-$k_t$ $R = 0.4$ jets built from stable particles ($\tau > 30\,$ps) and tau leptons excluding neutrinos and prompt dressed muons. Jets are $b$-tagged ($b$-jet) using ghost-matched $b$-hadrons with $p_{\text{T}} > 5\,$GeV. Apart from the kinematic requirements, isolation and overlap removal criteria are applied. Jets within $\Delta R = 0.4$ of a photon are removed if the $p_{\text{T}}$ of charged particles within $\Delta R = 0.3$ of the photon is smaller than $10\,\%$ of its $p_{\text{T}}$. Jets within $\Delta R = 0.4$ of a lepton are removed. Events are removed where a photon is close ($\Delta R < 0.4$) to a lepton or a surviving jet. The measured fiducial particle-level cross section is $\sigma_{tq\gamma}\times\mathcal{B}(t\rightarrow l\nu b)+\sigma_{t(\rightarrow l\nu b\gamma)q} = 303\pm 9(\text{stat.})^{+33}_{-32}(\text{syst.})\,$fb.
Measurements of differential and double-differential cross sections of top quark pair ($\text{t}\overline{\text{t}}$) production are presented in the lepton+jets channels with a single electron or muon and jets in the final state. The analysis combines for the first time signatures of top quarks with low transverse momentum $p_\text{T}$, where the top quark decay products can be identified as separated jets and isolated leptons, and with high $p_\text{T}$, where the decay products are collimated and overlap. The measurements are based on proton-proton collision data at $\sqrt{s} = $ 13 TeV collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 137 fb$^{-1}$. The cross sections are presented at the parton and particle levels, where the latter minimizes extrapolations based on theoretical assumptions. Most of the measured differential cross sections are well described by standard model predictions with the exception of some double-differential distributions. The inclusive $\text{t}\overline{\text{t}}$ production cross section is measured to be $\sigma_{\text{t}\overline{\text{t}}} = $ 791 $\pm$ 25 pb, which constitutes the most precise measurement in the lepton+jets channel to date.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
differential cross sections.
A search for the production of heavy partners of the top quark with charge 5/3 is performed in events with a pair of same-sign leptons. The data sample corresponds to an integrated luminosity of 19.5 inverse femtobarns and was collected at sqrt(s) = 8 TeV by the CMS experiment. No significant excess is observed in the data above the expected background and the existence of top-quark partners with masses below 800 GeV is excluded at a 95% confidence level, assuming they decay exclusively to tW. This is the first limit on these particles from the LHC, and it is significantly more restrictive than previous limits.
The distribution of HT for all channels combined after the full selection except for the HT requirement itself.
Expected and observed 95% CL limits on the $\mathrm{T}_{5/3}$ production cross section times the branching fraction for decay to same-sign dileptons.
The distribution of HT for all channels combined, after the requirement of same- sign dileptons, the Z-boson veto, and a requirement of at least two jets.
The distribution of the reconstructed $\mathrm{T}_{5/3}$ mass for the data, the background, and three signal mass points.
When you search on a word, e.g. 'collisions', we will automatically search across everything we store about a record. But sometimes you may wish to be more specific. Here we show you how.
Guidance on the query string syntax can also be found in the OpenSearch documentation.
We support searching for a range of records using their HEPData record ID or Inspire ID.
About HEPData Submitting to HEPData HEPData File Formats HEPData Coordinators HEPData Terms of Use HEPData Cookie Policy
Status
Email
Forum
Twitter
GitHub
Copyright ~1975-Present, HEPData | Powered by Invenio, funded by STFC, hosted and originally developed at CERN, supported and further developed at IPPP Durham.