Total cross sections for Sigma- and pi- on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600GeV/c. These measurements were performed with a transmission technique adapted to the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron-nucleus cross sections and on results for sigma_tot(Sigma- N) and sigma_tot(pi- N), which were deduced from nuclear cross sections.
We report a measurement of the electroweak parameters sin2θw and ϱ based on the ratios of neutral current to charged current events measured in the Fermilab narrow-band neutrino beam at energies of 30–240 GeV. The data are fully corrected for radiative effects, heavy-quark production, and other effects. The best value for sin2θw obtained, sin2θw=0.239±0.011, is consistent with the most recent values fromW andZ production, as well as from other neutrino experiments.
This paper reports on measurements of the total cross section for the inclusive reaction vμ+N, as a function of incident energy. Neutrinos and antineutrinos with energy in the range 3
A measurement of the b-hadron production cross section in proton-proton collisions at sqrt(s)=7 TeV is presented. The dataset, corresponding to 85 inverse nanobarns, was recorded with the CMS experiment at the LHC using a low-threshold single-muon trigger. Events are selected by the presence of a muon with transverse momentum greater than 6 GeV with respect to the beam direction and pseudorapidity less than 2.1. The transverse momentum of the muon with respect to the closest jet discriminates events containing b hadrons from background. The inclusive b-hadron production cross section is presented as a function of muon transverse momentum and pseudorapidity. The measured total cross section in the kinematic acceptance is sigma(pp to b+X to mu + X') =1.32 +/- 0.01 (stat) +/- 0.30 (syst) +/- 0.15 (lumi) microbarns.
The Upsilon production cross section in proton-proton collisions at sqrt(s) = 7 TeV is measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3.1 +/- 0.3 inverse picobarns. Integrated over the rapidity range |y|<2, we find the product of the Upsilon(1S) production cross section and branching fraction to dimuons to be sigma(pp to Upsilon(1S) X) B(Upsilon(1S) to mu+ mu-) = 7.37 +/- 0.13^{+0.61}_{-0.42}\pm 0.81 nb, where the first uncertainty is statistical, the second is systematic, and the third is associated with the estimation of the integrated luminosity of the data sample. This cross section is obtained assuming unpolarized Upsilon(1S) production. If the Upsilon(1S) production polarization is fully transverse or fully longitudinal the cross section changes by about 20%. We also report the measurement of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential cross sections as a function of transverse momentum and rapidity.
Measurements of the total and differential cross sections with respect to transverse momentum and rapidity for B+ mesons produced in pp collisions at sqrt(s) = 7 TeV are presented. The data correspond to an integrated luminosity of 5.8 inverse picobarns collected by the CMS experiment operating at the LHC. The exclusive decay B+ to J/psi K+, with the J/psi decaying to an oppositely charged muon pair, is used to detect B+ mesons and to measure the production cross section as a function of the transverse momentum and rapidity of the B. The total cross section for p_t(B) > 5 GeV and |y(B)| < 2.4 is measured to be 28.1 +/- 2.4 +/- 2.0 +/- 3.1 microbarns, where the first uncertainty is statistical, the second is systematic, and the last is from the luminosity measurement.
Measurements of inclusive W and Z boson production cross sections in pp collisions at sqrt(s)=7 TeV are presented, based on 2.9 inverse picobarns of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give sigma(pp to WX) times B(W to muon or electron + neutrino) = 9.95 \pm 0.07(stat.) \pm 0.28(syst.) \pm 1.09(lumi.) nb and sigma(pp to ZX) times B(Z to oppositely charged muon or electron pairs) = 0.931 \pm 0.026(stat.) \pm 0.023(syst.) \pm 0.102(lumi.) nb. Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.
A search for exotic decays of the Higgs boson to a pair of light pseudoscalar particles a$_1$ is performed under the hypothesis that one of the pseudoscalars decays to a pair of opposite sign muons and the other decays to b$\overline{\mathrm{b}}$. Such signatures are predicted in a number of extensions of the standard model (SM), including next-to-minimal supersymmetry and two-Higgs-doublet models with an additional scalar singlet. The results are based on a data set of proton-proton collisions corresponding to an integrated luminosity of 35.9 fb$^{-1}$, accumulated with the CMS experiment at the CERN LHC in 2016 at a centre-of-mass energy of 13 TeV. No statistically significant excess is observed with respect to the SM backgrounds in the search region for pseudoscalar masses from 20 GeV to half of the Higgs boson mass. Upper limits at 95% confidence level are set on the product of the production cross section and branching fraction, $\sigma_{\mathrm{h}}\mathcal{B}$(h $\to$ a$_1$ a$_1$ $\to$ $\mu^+\mu^-\mathrm{b}\bar{\mathrm{b}}$), ranging from 5 to 33 fb, depending on the pseudoscalar mass. Corresponding limits on the branching fraction, assuming the SM prediction for $\sigma_{\mathrm{h}}$, are (1$-$7)$\times$ 10$^{-4}$.
The production of J/psi mesons is studied in pp collisions at sqrt(s)=7 TeV with the CMS experiment at the LHC. The measurement is based on a dimuon sample corresponding to an integrated luminosity of 314 inverse nanobarns. The J/psi differential cross section is determined, as a function of the J/psi transverse momentum, in three rapidity ranges. A fit to the decay length distribution is used to separate the prompt from the non-prompt (b hadron to J/psi) component. Integrated over J/psi transverse momentum from 6.5 to 30 GeV/c and over rapidity in the range |y| < 2.4, the measured cross sections, times the dimuon decay branching fraction, are 70.9 \pm 2.1 (stat.) \pm 3.0 (syst.) \pm 7.8(luminosity) nb for prompt J/psi mesons assuming unpolarized production and 26.0 \pm 1.4 (stat.) \pm 1.6 (syst.) \pm 2.9 (luminosity) nb for J/psi mesons from b-hadron decays.
The first measurement of the cross section for top-quark pair production in pp collisions at the LHC at center-of-mass energy sqrt(s)= 7 TeV has been performed using 3.1 {\pm} 0.3 inverse pb of data recorded by the CMS detector. This result utilizes the final state with two isolated, highly energetic charged leptons, large missing transverse energy, and two or more jets. Backgrounds from Drell-Yan and non-W/Z boson production are estimated from data. Eleven events are observed in the data with 2.1 {\pm} 1.0 events expected from background. The measured cross section is 194 {\pm} 72 (stat.) {\pm} 24 (syst.) {\pm} 21 (lumi.) pb, consistent with next-to-leading order predictions.