No abstract

We summarize and combine direct measurements of the mass of the W boson in √ s = 1.96 TeV proton-antiproton collision data collected by CDF and D0 experiments at the Fermilab Tevatron Collider. Earlier measurements from CDF and D0 are combined with the two latest, more precise measurements: a CDF measurement in the electron and muon channels using data corresponding to 2.2 fb −1 of integrated luminosity, and a D0 measurement in the electron channel using data corresponding to 4.3 fb −1 of integrated luminosity. The resulting Tevatron average for the mass of the W boson is MW = 80 387 ± 16 MeV. Including measurements obtained in electron-positron collisions at LEP yields the most precise value of MW = 80 385 ± 15 MeV.

Results are presented of a search for heavy stable charged particles produced in proton-proton collisions at ffiffi ffi s p ¼ 13 TeV using a data sample corresponding to an integrated luminosity of 2.5 fb −1 collected in 2015 with the CMS detector at the CERN LHC. The search is conducted using signatures of anomalously high energy deposits in the silicon tracker and long time-of-flight measurements by the muon system. The data are consistent with the expected background, and upper limits are set on the cross sections for production of long-lived gluinos, top squarks, tau sleptons, and leptonlike long-lived fermions. These upper limits are equivalently expressed as lower limits on the masses of new states; the limits for gluinos, ranging up to 1610 GeV, are the most stringent to date. Limits on the cross sections for direct pair production of long-lived tau sleptons are also determined.

We present a search for new particles which produce narrow two-jet (dijet) resonances using protonantiproton collision data corresponding to an integrated luminosity of 1:13 fb À1 collected with the CDF II detector. The measured dijet mass spectrum is found to be consistent with next-to-leading-order perturbative QCD predictions, and no significant evidence of new particles is found. We set upper limits at the 95% confidence level on cross sections times the branching fraction for the production of new particles decaying into dijets with both jets having a rapidity magnitude jyj < 1. These limits are used to determine the mass exclusions for the excited quark, axigluon, flavor-universal coloron, E 6 diquark, coloroctet techni-, W 0 , and Z 0 .

We present a measurement of the mass of the top quark from proton-antiproton collisions recorded at the CDF experiment in Run II of the Fermilab Tevatron. We analyze events from the single lepton plus jets final state (tt-->W(+)bW(-)b-->lnubqq'b). The top-quark mass is extracted using a direct calculation of the probability density that each event corresponds to the tt final state. The probability is a function of both the mass of the top quark and the energy scale of the calorimeter jets, which is constrained in situ by the hadronic W boson mass. Using 167 events observed in 955 pb(-1) of integrated luminosity, we achieve the single most precise measurement of the top-quark mass, 170.8+/-2.2(stat.)+/-1.4(syst.) GeV/c(2).