We present a study of inclusive π0 and ŋ production ine+e− annihilation at
Particle multiplicities in the continuum.
Particle multiplicities in the UPSILON (1S).
Inclusive pi0 spectra in the continuum.
The differential cross section for elastic antiproton—proton scattering at s =1.8 TeV has been measured over the t range 0.034⩽| t |⩽0.65 (GeV/ c ) 2 . A logarithmic slope parameter, B , of 16.3±0.3 (GeV/ c ) −2 is obtained. In contrast to lower energy experiments, no change in slope is observed over this t range.
Numerical values from FERMILAB-FN-562 suppliedto us by R. Rubinstein. Statistical errors only. t values at centre of each bin.
Nuclear slope parameter. Error contains 0.3 GeV**-2 systematic uncertainty folded.
None
No description provided.
No description provided.
The Crystal Ball detector has been used at the DORIS II storage ring at DESY to study the reactionγγ→π0π0π0 in theπ0π0π0 invariant mass range from 850 MeV/c2 to 2600 MeV/c2. An enhancement around 1750 MeV/c2 is attributed to theπ2(1670) resonance. The observedπ0π0 invariant mass distribution and theπ0 angular distributions are consistent with those expected for the decay chainπ2→π0f2(1270)→π0π0π0. From our measurements we find the following resonance parameters: two photon partial width\(\Gamma _{\pi _2 }^{\gamma \gamma }= (1.41 \pm 0.23 \pm 0.28)keV\), massM(π2)=(1742±31±49)MeV/c2. and total width\(\Gamma _{\pi _2 }^{tot}= (236 \pm 49 \pm 36)MeV\).
Data read from graph.
Cross section times branching ratio to 3pi0 assuming the decay chain pi2 --> pi0f2 --> 3pi0.
We report a measurement of the p p total cross section at √ s =1.8 TeV using a luminosity-independent method. Our result is σ T =72.1±3.3 mb ; we also derive the total elastic cross section σ el =16.6±1.6 mb. A value is obtained for the total single diffraction cross section of 11.7±2.3 mb.
No description provided.
Assuming RHO = 0.145.
No description provided.
None
No description provided.
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RUN 1.
RUN 1.
RUN 1.
The charged-particle fractional momentum distribution within jets, D(z), has been measured in dijet events from 1.8-TeV p¯p collisions in the Collider Detector at Fermilab. As expected from scale breaking in quantum chromodynamics, the fragmentation function D(z) falls more steeply as dijet invariant mass increases from 60 to 200 GeV/c2. The average fraction of the jet momentum carried by charged particles is 0.65±0.02(stat)±0.08(syst).
No description provided.
The reaction e+e−→e+e−π0π0 has been analyzed using 97 pb−1 of data taken with the Crystal Ball detector at the DESY e−e+ storage ring DORIS II at beam energies around 5.3 GeV. For the first time we have measured the cross section for γγ→π0π0 for π0π0 mvariant masses ranging from threshold to about 2 GeV. We measure an approximately flat cross section of about 10 nb for W=mπ0π0<0.8 GeV, which is below 0.6 GeV, in good agreement with a theoretical prediction based on an unitarized Born-term model. At higher invariant masses we observe formation of the f2(1270) resonance and a hint of the f0(975). We deduce the following two-photon widths: Γγγ(f2(1270))=3.19±0.16±0.280.29 keV and Γγγ(f0(975))<0.53 keV at 90% C.L. The decay-angular distributions show the π0π0 system to be dominantly spin 0 for W<0.7 GeV and spin 2, helicity 2 in the f2(1270) region, with helicity 0 contributing at most 22% (90% C.L.).
Statistical errors only.
Statistical errors only.
A proton-proton bremsstrahlung experiment has been carried out at TRIUMF using a 280-MeV polarized proton beam impinging on a liquid-hydrogen target. All three outgoing particles were detected: the higher-energy proton in a magnetic spectrometer, the lower-energy proton with plastic scintillators, and the photon in lead-glass Cherenkov detectors. The experiment shows the first unambiguous evidence for off-shell effects in the free nucleon-nucleon interaction, in that the analyzing powers disagree strongly with the predictions of the soft-photon approximation (which incorporates only on-shell information) but are consistent with the results of calculations using the Bonn and Paris potentials.
Estimated scale uncertainty is 1.5 pct.
Estimated scale uncertainty is 1.5 pct.
Estimated scale uncertainty is 1.5 pct.