The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. The Higgs boson was the last missing component of the model. After observation of the Higgs boson, a measurement of the W boson mass provides a stringent test of the model. We measure the W boson mass, M _W , using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at a 1.96 tera–electron volt center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. A sample of approximately 4 million W boson candidates is used to obtain M W = 80 , 433.5 ± 6.4 stat ± 6.9 syst = 80 , 433.5 ± 9.4 MeV / c 2 , the precision of which exceeds that of all previous measurements combined (stat, statistical uncertainty; syst, systematic uncertainty; MeV, mega–electron volts; c , speed of light in a vacuum). This measurement is in significant tension with the standard model expectation.

A measurement of the production processes of the recently discovered Higgs boson is performed in the two-photon final state using $4.5{\mathrm{fb}}^{-1}$ of proton-proton collisions data at $\sqrt{s}=7\mathrm{TeV}$ and $20.3{\mathrm{fb}}^{-1}$ at $\sqrt{s}=8\mathrm{TeV}$ collected by the ATLAS detector at the Large Hadron Collider. The number of observed Higgs boson decays to diphotons divided by the corresponding Standard Model prediction, called the signal strength, is found to be $\mu =1.17\pm 0.27$ at the value of the Higgs boson mass measured by ATLAS, $m_H=125.4\mathrm{GeV}$. The analysis is optimized to measure the signal strengths for individual Higgs boson production processes at this value of $m_H$. They are found to be ${\mu }_{\mathrm{ggF}}=1.32\pm 0.38$, ${\mu }_{\mathrm{VBF}}=0.8\pm 0.7$, ${\mu }_{WH}=1.0\pm 1.6$, ${\mu }_{ZH}={0.1}_{-0.1}^{+3.7}$, and ${\mu }_{t\overline{t}H}={1.6}_{-1.8}^{+2.7}$, for Higgs boson production through gluon fusion, vector-boson fusion, and in association with a $W$ or $Z$ boson or a top-quark pair, respectively. Compared with the previously published ATLAS analysis, the results reported here also benefit from a new energy calibration procedure for photons and the subsequent reduction of the systematic uncertainty on the diphoton mass resolution. No significant deviations from the predictions of the Standard Model are found.

This paper presents the performance of the ATLAS muon reconstruction during the LHC run with [equation] collisions at [equation]–8 TeV in 2011–2012, focusing mainly on data collected in 2012....

This paper presents the electron and photon energy calibration achieved with the ATLAS detector using about 25 fb[equation] of LHC proton–proton collision data taken at centre-of-mass energies of [equation]...

Many of the interesting physics processes to be measured at the LHC have a signature involving one or more isolated electrons. The electron reconstruction and identification efficiencies of the ATLAS detector at the LHC have been evaluated using proton–proton collision data collected in 2011 at \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\sqrt{s}= 7$$\end{document}s=7 TeV and corresponding to an integrated luminosity of 4.7 fb\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{-1}$$\end{document}-1. Tag-and-probe methods using events with leptonic decays of \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$W$$\end{document}W and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$Z$$\end{document}Z bosons and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$J/\psi $$\end{document}J/ψ mesons are employed to benchmark these performance parameters. The combination of all measurements results in identification efficiencies determined with an accuracy at the few per mil level for electron transverse energy greater than 30 GeV.

Evidence is reported for a narrow structure near the $J/\psi \varphi$ threshold in exclusive $B^{+}\to J/\psi \varphi K^{+}$ decays produced in $\overline{p}p$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$. A signal of $14\pm 5$ events, with statistical significance in excess of 3.8 standard deviations, is observed in a data sample corresponding to an integrated luminosity of $2.7{\mathrm{fb}}^{-1}$, collected by the CDF II detector. The mass and natural width of the structure are measured to be $4143.0\pm 2.9(\mathrm{stat})\pm 1.2(\mathrm{syst})\mathrm{MeV}/c^2$ and ${11.7}_{-5.0}^{+8.3}(\mathrm{stat})\pm 3.7(\mathrm{syst})\mathrm{MeV}/c^2$.