A MEASUREMENT OF THE TOTAL HADRONIC CROSS-SECTION IN TAGGED gamma gamma REACTIONS

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.D 41 (1990) 2667, 1990.
Inspire Record 281351 DOI 10.17182/hepdata.22991

We present a measurement of the total cross section for γγ→hadrons, with one photon quasireal and the other a spacelike photon of mass squared −Q2. Results are presented as a function of Q2 and the γγ center-of-mass energy W, with the Q2 range extending from 0.2 to 60 GeV2, and W in the range from 2 to 10 GeV. The data were taken with the TPC/Two-Gamma facility at the SLAC e+e− storage ring PEP, which was operated at a beam energy of 14.5 GeV. The cross section exhibits a gentle falloff with increasing W. Its Q2 dependence is shown to be well described by an incoherent sum of vector-meson and pointlike scattering over most of the observed W range. Agreement at high Q2 is improved if a minimum-pT cutoff (motivated by QCD) is imposed on the pointlike contribution.

4 data tables

Errors are statistical only.

Errors are statistical only.

Errors are statistical only.

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The Acceleration of Polarized Protons to 22-{GeV}/$c$ and the Measurement of Spin Spin Effects in $p$ (Polarized) + $p$ (Polarized) $\to p + p$

Khiari, F.Z. ; Cameron, P.R. ; Court, G.R. ; et al.
Phys.Rev.D 39 (1989) 45, 1989.
Inspire Record 262472 DOI 10.17182/hepdata.23245

Accelerating polarized protons to 22 GeV/c at the Brookhaven Alternating Gradient Synchro- tron required both extensive hardware modifications and a difficult commissioning process. We had to overcome 45 strong depolarizing resonances to maintain polarization up to 22 GeV/c in this strong-focusing synchrotron. At 18.5 GeV/c we measured the analyzing power A and the spin-spin correlation parameter Ann in large- P⊥2 proton-proton elastic scattering, using the polarized proton beam and a polarized proton target. We also obtained a high-precision measurement of A at P⊥2=0.3 (GeV/c)2 at 13.3 GeV/c. At 18.5 GeV/c we found that Ann=(-2±16)% at P⊥2=4.7 (GeV/c)2, where it was about 60% near 12 GeV at the Argonne Zero Gradient Synchrotron. This sharp change suggests that spin-spin forces may have a strong and unexpected energy dependence at high P⊥2.

3 data tables

No description provided.

2.2 GeV point taken from Brown et al., PR D31(85) 3017.

No description provided.


Energy Dependence of Spin Effects in $p$ (Polarized) $p$ (Polarized) $\to p p$

Court, G.R. ; Crabb, D.G. ; Gialas, I. ; et al.
Phys.Rev.Lett. 57 (1986) 507, 1986.
Inspire Record 229812 DOI 10.17182/hepdata.20190

We measured the analyzing power A and the spin-spin correlation parameter Ann, in large-P⊥2 proton-proton elastic scattering, using a polarized-proton target and the polarized-proton beam at the Brookhaven Alternating-Gradient Synchrotron. We also used our polarimeter to measure A at small P⊥2 at 13 GeV with good precision and found some deviation from the expected 1Plab behavior. At 18.5 GeV/c we found Ann=(−2±16)% at P⊥2=4.7 (GeV/c)2. Comparison with lower-energy data from the Argonne Zero-Gradient Synchrotron shows a sharp and surprising energy dependence for Ann at large P⊥2.

3 data tables

POL is error weighted average of polarized beam and target measurements.

POL is error-weighted average of polarized beam and target measurements.

POL is error-weighted average of polarized beam and target measurement.


Inclusive Production of $D$ and $K$ Mesons in $e^+ e^-$ Annihilation

Piccolo, M. ; Peruzzi, I. ; Rapidis, P.A. ; et al.
Phys.Lett.B 86 (1979) 220-224, 1979.
Inspire Record 141018 DOI 10.17182/hepdata.27301

We present measurements of the cross section for inclusive D and K meson production in e + e − annihilation in the center of mass energy range 3.6 to 5.8 GeV. D production accounts for most of the increase in the total cross section for hadron production in e + e − annihilation at energies above 4 GeV.

3 data tables

No description provided.

No description provided.

No description provided.


Scattering of antineutrons by protons

Franklin, A.D. ; Socash, R.R. ;
Phys.Rev. 184 (1969) 1413-1414, 1969.
Inspire Record 62285 DOI 10.17182/hepdata.5406

The total and elastic cross sections for antineutrons on protons have been measured for antineutron momenta from 0.5 to 2.5 GeV/c. The results are in agreement with previous p¯p data at these momenta.

2 data tables

'1'. '2'. '3'.

No description provided.