Jet cross sections were measured in charged current deep inelastic e+-p scattering at high boson virtualities Q^2 with the ZEUS detector at HERA II using an integrated luminosity of 0.36 fb^-1. Differential cross sections are presented for inclusive-jet production as functions of Q^2, Bjorken x and the jet transverse energy and pseudorapidity. The dijet invariant mass cross section is also presented. Observation of three- and four-jet events in charged-current e+-p processes is reported for the first time. The predictions of next-to-leading-order (NLO) QCD calculations are compared to the measurements. The measured inclusive-jet cross sections are well described in shape and normalization by the NLO predictions. The data have the potential to constrain the u and d valence quark distributions in the proton if included as input to global fits.
Differential polarized inclusive jet cross sections as a function of jet pseudorapidity.
Differential polarized inclusive jet cross sections as a function of jet pseudorapidity.
Differential polarized inclusive jet cross sections as a function of jet transverse energy.
Single particles and jets in deeply inelastic scattering at low x are measured with the H1 detector in the region away from the current jet and towards the proton remnant, known as the forward region. Hadronic final state measurements in this region are expected to be particularly sensitive to QCD evolution effects. Jet cross-sections are presented as a function of Bjorken-x for forward jets produced with a polar angle to the proton direction, theta, in the range 7 < theta < 20 degrees. Azimuthal correlations are studied between the forward jet and the scattered lepton. Charged and neutral single particle production in the forward region are measured as a function of Bjorken-x, in the range 5 < theta < 25 degrees, for particle transverse momenta larger than 1 GeV. QCD based Monte Carlo predictions and analytical calculations based on BFKL, CCFM and DGLAP evolution are compared to the data. Predictions based on the DGLAP approach fail to describe the data, except for those which allow for a resolved photon contribution.
Forward Jet cross section. Axis error includes +- 7/7 contribution (Dependence of the model used to correct the data).
Forward Di-jet cross section. Axis error includes +- 7/7 contribution (Dependence of the model used to correct the data).
Data from Figure 3a on charged particle production
This paper presents measurements of \k\ and \lam\ production in neutral current, deep inelastic scattering of 26.7 GeV electrons and 820 GeV protons in the kinematic range $ 10 < Q~{2} < 640 $ GeV$~2$, $0.0003 < x < 0.01$, and $y > 0.04$. Average multiplicities for \k\ and \lam\ production are determined for transverse momenta \ \ptr\ $> 0.5 $ GeV and pseudorapidities $\left| \eta \right| < 1.3$. The multiplicities favour a stronger strange to light quark suppression in the fragmentation chain than found in $e~+ e~-$ experiments. The production properties of \k's in events with and without a large rapidity gap with respect to the proton direction are compared. The ratio of neutral \k's to charged particles per event in the measured kinematic range is, within the present statistics, the same in both samples.
No description provided.
No description provided.
No description provided.
None
No description provided.
No description provided.
No description provided.
None
AVERAGE OVER ALL TARGETS.
No description provided.
No description provided.
None
Axis error includes +- 0.0/0.0 contribution (?////NOT GIVEN).
Axis error includes +- 0.0/0.0 contribution (?////NOT GIVEN).
No description provided.
First measurements of the W -> lnu and Z/gamma* -> ll (l = e, mu) production cross sections in proton-proton collisions at sqrt(s) = 7 TeV are presented using data recorded by the ATLAS experiment at the LHC. The results are based on 2250 W -> lnu and 179 Z/gamma* -> ll candidate events selected from a data set corresponding to an integrated luminosity of approximately 320 nb-1. The measured total W and Z/gamma*-boson production cross sections times the respective leptonic branching ratios for the combined electron and muon channels are $\stotW$ * BR(W -> lnu) = 9.96 +- 0.23(stat) +- 0.50(syst) +- 1.10(lumi) nb and $\stotZg$ * BR(Z/gamma* -> ll) = 0.82 +- 0.06(stat) +- 0.05(syst) +- 0.09(lumi) nb (within the invariant mass window 66 < m_ll < 116 GeV). The W/Z cross-section ratio is measured to be 11.7 +- 0.9(stat) +- 0.4(syst). In addition, measurements of the W+ and W- production cross sections and of the lepton charge asymmetry are reported. Theoretical predictions based on NNLO QCD calculations are found to agree with the measurements.
Measured fiducial cross section times leptonic branching ratio for W+ production in the W+ -> e+ nu final state.
Measured fiducial cross section times leptonic branching ratio for W- production in the W- -> e- nubar final state.
Measured fiducial cross section times leptonic branching ratio for W+/- production in the combined W+ -> e+ nu and W- -> e- nubar final state.
An analysis was made of 355 interactions between 1r- mesons and nucleons. The momentum and angular distributions of the secondary charged particles were measured. Information on 1r0 mesons produced in the interactions has been obtained. The experimental data are compared with the statistical theory. The results suggest that peripheral interactions may exist. In events of low multiplicity (two-prong cases) "one-meson" peripheral interactions play an important role, while in events of large multiplicity an important role is played by interactions not of the one-meson type, among which also central collisions are possible.
No description provided.
No description provided.
The simultaneous production of pion resonances and strange particles was investigated. The simultaneous production of p 0 mesons and A-K pairs was observed in events characterized by charged particle multiplicity ns = 4 and having cross sections upo = 20 ± 8 ~b. Cross sections for the production of w and YJ resonances are presented. The 1340-MeV peak in the distribution of four-pion effective masses is discussed.
No description provided.
The production of A ( ~ 0 ) hyperons (henceforth denoted A hyperons for short) and K 0 mesons by negative pions on carbon was investigated. The angular and momentum distribu- tions of these particles and the cross sections for their production are determined, and the cross sections of the different channels of the reactions are estimated. The fraction of strange particles produced in the secondary processes is estimated for the first time. The momentum spectrum of the A hyperons (in the pion-nucleon c.m.s.) is compared with the spectrum for rr-p interactions. The experimental data are compared with the results of cascade-model calculations made by the Monte Carlo method.
No description provided.
Forum