The production of very large transverse momentum hadron jets has been measured in the UA2 experiment at the CERN p p Collider for s = 540 GeV using a highly segmented calorimeter. The range of previously available cross sections for inclusive jet production is extended to p T = 150 GeV and the two-jet invariant mass distribution to m jj = 280 GeV with the largely increased data sample collected during the 1983 running period. The results are compared with the predictions of QCD models.
LISTED ERRORS INCLUDE STATISTICAL AND THE PT-DEPENDENT UNCERTAINTIES. THE ADDITIONAL OVERALL SYSTEMATIC UNCERTAINTY IS 45PCT.
LISTED ERRORS INCLUDE STATISTICAL AND THE M-DEPENDENT UNCERTAINTIES. THE ADDITIONAL OVERALL SYSTEMATIC UNCERTAINTY IS 45PCT.
Using annihilation in a calorimeter as a trigger on antiprotons, we have measured the relative production cross sections of p , Λ and Ξ at y∼0 in the transverse momentum range 1 to 2 GeV/ c in pp collisions at √ s =63 GeV. We investigate correlations between the antibaryons and associated produced particles, and find evidence for local baryon number conservation.
No description provided.
Inclusive π 0 production has been measured at the CERN pp̄ collider, s =540 GeV , for 90° production angle and in a range of transverse momenta between 1.5 and 4.5 GeV/ c . The invariant production cross section is larger than that measured at s = 53 GeV for p-p collisions. The production of μ mesons aand of direct photons is also investigated.
No description provided.
We present results from a direct photon pair search performed with the NA3 spectrometer, using incident positive and negative beams at 200 GeV/ c interacting with a carbon target. The experiment is sensitive to photons with p T >1.8 GeV / c and −0.4⩽y ∗ ⩽1.0 , one in each arm of the apparatus. A 3 standard deviation signal is seen in τ − and p interactions. The cross section is higher than the second order QCD calculations, but systematic errors are large.
No description provided.
The inclusive jet cross section has been measured in the UA1 experiment at the CERN p p Collider at centre-of-mass energies √ s = 546 GeV and √ s = 630 eV. The cross sections are found to be consistent with QCD predictions, The observed change in the cross section with the centre-of-mass energy √ s is accounted for in terms of x T scaling.
No description provided.
The production of very large transverse momentum ( p T ) hadron jets has been measured in the UA2 experiment at the CERN p p Collider for s =630 GeV . The inclusive jet production cross sections exhibit a p T -dependent increase with respect to the s =546 GeV data from previous Collider runs. This increase can be described both by QCD calculations and by approximate x T =2 p T /√ s scaling. No significant deviation of the data from QCD predictions is observed at very large p T , placing a lower limit on the characteristic scale Λ c of a hypothetical superstrong contact interaction responsible for the binding of preons in the quark ( Λ c >370 GeV at 95% CL).
No description provided.
This paper describes a measurement of the W boson transverse momentum distribution using ATLAS pp collision data from the 2010 run of the LHC at sqrt(s) = 7 TeV, corresponding to an integrated luminosity of about 31 pb^-1. Events from both W -> e nu and W -> mu nu are used, and the transverse momentum of the W candidates is measured through the energy deposition in the calorimeter from the recoil of the W. The resulting distributions are unfolded to obtain the normalized differential cross sections as a function of the W boson transverse momentum. We present results for pTW < 300 GeV in the electron and muon channels as well as for their combination, and compare the combined results to the predictions of perturbative QCD and a selection of event generators.
The normalized, differential cross secton measured in the W to Electron decay channel for the three different PT definitions, Born, Dressed and Bare.
The normalized, differential cross secton measured in the W to Muon decay channel for the three different PT definitions, Born, Dressed and Bare.
The normalized, differential cross secton from the Muon and Electron decay channel Combined for the Born-level PT definition.
A study of events containing at least four high transverse momentum jets and a search for double parton scattering (DPS) have been performed using data collected with the UA2 detector at the CERN p p Collider (√ s =630 GeV). The results are in good agreement with leading order QCD calculations. A value of σ DPS <0.82 nb at 95% confidence level (CL) is obtained for the DPS cross section.
Data requested from authors.
Uncorrected cross sections.
Upper limit to DPS contribution to 4JET production.
None
No description provided.
CONTINUUM MUONS ORIGINATE MAINLY FROM VECTOR MESON DECAYS, SEMI-LEPTONIC DECAYS OF D DBAR PAIRS AND FROM DRELL-YAN MECHANISM.
No description provided.
A measurement of the cross-sections for single and double prompt photon production in p p interactions at s = 630 GeV is presented. The data sample corresponds to an integrated luminosity of 13.2 pb −1 . The results are in good agreement with the predictions of perturbative QCD. The signal from double prompt photon production has a statistical significance of 4.3 standard deviations.
There is an overall systematic error of 9 pct not included in the table.
Errors quoted include statistical and all PT dependent systematic uncertainties. There is in addition a 6.8 pct overall normalization uncertainty.