Cross section measurements of charged pion photoproduction in hydrogen and deuterium from 1.1-GeV to 5.5-GeV.

The Jefferson Lab Hall A & Jefferson Lab E94-104 collaborations Zhu, L.Y. ; Arrington, J. ; Averett, T. ; et al.
Phys.Rev.C 71 (2005) 044603, 2005.
Inspire Record 659852 DOI 10.17182/hepdata.31680

The differential cross section for the gamma +n --> pi- + p and the gamma + p --> pi+ n processes were measured at Jefferson Lab. The photon energies ranged from 1.1 to 5.5 GeV, corresponding to center-of-mass energies from 1.7 to 3.4 GeV. The pion center-of-mass angles varied from 50 degree to 110 degree. The pi- and pi+ photoproduction data both exhibit a global scaling behavior at high energies and high transverse momenta, consistent with the constituent counting rule prediction and the existing pi+ data. The data suggest possible substructure of the scaling behavior, which might be oscillations around the scaling value. The data show an enhancement in the scaled cross section at center-of-mass energy near 2.2 GeV. The differential cross section ratios at high energies and high transverse momenta can be described by calculations based on one-hard-gluon-exchange diagrams.

14 data tables

Differential cross section for the process GAMMA N --> PI- P for an incident electron energy of 5.614 GeV.

Differential cross section for the process GAMMA N --> PI- P for an incident electron energy of 4.236 GeV.

Differential cross section for the process GAMMA N --> PI- P for an incident electron energy of 3.400 GeV.

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Cross section measurement of charged pion photoproduction from hydrogen and deuterium.

The Jefferson Lab Hall A collaboration Zhu, L.Y. ; Arrington, J. ; Averett, T. ; et al.
Phys.Rev.Lett. 91 (2003) 022003, 2003.
Inspire Record 601768 DOI 10.17182/hepdata.31722

We have measured the differential cross section for the gamma n --> pi- p and gamma p --> pi+ n reactions at center of mass angle of 90 degree in the photon energy range from 1.1 to 5.5 GeV at Jefferson Lab (JLab). The data at photon energies greater than 3.3 GeV exhibit a global scaling behavior for both pi- and pi+ photoproduction, consistent with the constituent counting rule and the existing pi+ photoproduction data. Possible oscillations around the scaling value are suggested by these new data The data show enhancement in the scaled cross section at a center-of-mass energy near 2.2 GeV. The cross section ratio of exclusive pi- to pi+ photoproduction at high energy is consistent with the prediction based on one-hard-gluon-exchange diagrams.

1 data table

Differential cross section at THETA(CM) = 90 degrees.


Photoproduction of Phi(1020) mesons on the proton at large momentum transfer.

The CLAS collaboration Anciant, E. ; Auger, T. ; Audit, G. ; et al.
Phys.Rev.Lett. 85 (2000) 4682-4686, 2000.
Inspire Record 528835 DOI 10.17182/hepdata.19491

The cross section for $\phi$ meson photoproduction on the proton has been measured for the first time up to a four-momentum transfer -t = 4 GeV^2, using the CLAS detector at the Thomas Jefferson National Accelerator Facility. At low four-momentum transfer, the differential cross section is well described by Pomeron exchange. At large four-momentum transfer, above -t = 1.8 GeV^2, the data support a model where the Pomeron is resolved into its simplest component, two gluons, which may couple to any quark in the proton and in the $\phi$.

1 data table

The differential PHI photoproduction cross section. The errors shown are the quadratic sum of the statistics and the systematic uncertainties which include 3 PCT for normalization, 5 PCT for acceptance and 5-15 PCT for background subtraction.