The dijet invariant mass distribution has been measured in the region between 140 and 1000 GeV/c2, in 1.8 TeV p p¯ collisions. Data collected with the Collider Detector at Fermilab show agreement with QCD calculations. A limit on quark compositeness of Λc>1.3 TeV is obtained. Axigluons with masses between 240 and 640 GeV/c2 are excluded at 95% C.L. if we assume ten open decay channels. Model-independent limits on the production of heavy particles decaying into two jets are also presented.
No description provided.
We present a measurement of the b-quark cross section in 1.8 TeV p-p¯ collisions recorded with the Collider Detector at Fermilab using muonic b-quark decays. In the central rapidity region (‖yb‖<1.0), the cross section is 295±21±75 nb (59±14±15 nb) for pTb>21 GeV/c (29 GeV/c). Comparisons are made to previous measurements and next-to-leading order QCD calculations.
No description provided.
We measure the Drell-Yan differential cross section d2σdMdy||y|<1 over the mass range 11
Dielectron differential cross section.
Dimuon differential cross section.
Drell-Yan differential cross section for combined dielectron and dimuon data. Error includes both statistics and systematics.
The inclusive jet cross section in photoproduction has been measured as a function of transverse energy and pseudorapidity using the H 1 detector at the HERA electron-proton collider. The results are compared with leading order QCD calculations.
No description provided.
No description provided.
A measurement of the proton structure function F 2 ( x , Q 2 ) is presented with about 1000 neutral current deep inelastic scattering events for Bjorken x in the range x ⋍ 10 −2 – 10 −4 and Q 2 > 5 GeV 2 . The measurement is based on an integrated luminosity of 22.5 nb −1 recorded by the H1 detector in the first year of HERA operation. The structure function F 2 ( x , Q 2 ) shows a significant rise with decreasing x .
No description provided.
No description provided.
No description provided.
Antiproton-proton elastic scattering was measured at c.m.s. energies √s =546 and 1800 GeV in the range of four-momentum transfer squared 0.025<-t<0.29 GeV2. The data are well described by the exponential form ebt with a slope b=15.28±0.58 (16.98±0.25) GeV−2 at √s =546 (1800) GeV. The elastic scattering cross sections are, respectively, σel=12.87±0.30 and 19.70±0.85 mb.
Final results (systematic errors included).
Final results (systematic errors included).
Statistical errors only. Data supplied by S. Belforte.
Cross sections for deep-inelastic electron scattering from liquid deuterium, gaseous He4, and solid Be, C, Al, Ca, Fe, Ag, and Au targets were measured at the Stanford Linear Accelerator Center using electrons with energies ranging from 8 to 24.5 GeV. These data cover a range in the Bjorken variable x from 0.089 to 0.8, and in momentum transfer Q2 from 2 to 15 (GeV/c)2. The ratios of cross sections per nucleon (σAσd)is for isoscalar nuclei have been extracted from the data. These ratios are greater than unity in the range 0.1
Additional overall systematic error of 2.1 pct plus a target to target systematic error of 1 pct.
Additional overall systematic error of 2.1 pct plus a target to target systematic error of 2.1 pct.
Additional overall systematic error of 2.1 pct plus a target to target systematic error of 0.6 pct.
We report a measurement of the diffraction dissociation differential cross section d2σSD/dM2dt for p¯p→p¯X at √s =546 and 1800 GeV, M2/s<0.2 and 0≤-t≤0.4 GeV2. Our results are compared to theoretical predictions and to extrapolations from experimental results at lower energies.
Single diffraction dissociation cross section.
We report a measurement of the proton-antiproton total cross section σT at c.m.s. energies √s =546 and 1800 GeV. Using the luminosity-independent method, we find σT=61.26±0.93 mb at √s =546 GeV and 80.03±2.24 mb at √s =1800 GeV. In this energy range, the ratio σel/σT increases from 0.210±0.002 to 0.246±0.004.
No description provided.
Assuming RHO = 0.15.
A measurement of the cross section for γγ→pp¯ is performed at two-photon center-of-mass energies between 2.00 and 3.25 GeV. These results are obtained using e+e−→e+e−pp¯ events selected from 1.31 fb−1 of data taken with the CLEO II detector. The measured cross section is in reasonable agreement with previous measurements and is in excellent agreement with recent calculations based on a diquark model. However, leading order QCD calculations performed using the Brodsky-Lepage formalism are well below the measured cross section.
Data read from graph.
Data read from graph.
Data read from graph.