$\pi^+$ photoproduction on the proton for photon energies from 0.725 to 2.875 GeV

The CLAS collaboration Dugger, M. ; Ritchie, B.G. ; Ball, J.P. ; et al.
Phys.Rev.C 79 (2009) 065206, 2009.
Inspire Record 814847 DOI 10.17182/hepdata.51952

Differential cross sections for the reaction $\gamma p \to n \pi^+$ have been measured with the CEBAF Large Acceptance Spectrometer (CLAS) and a tagged photon beam with energies from 0.725 to 2.875 GeV. Where available, the results obtained here compare well with previously published results for the reaction. Agreement with the SAID and MAID analyses is found below 1 GeV. The present set of cross sections has been incorporated into the SAID database, and exploratory fits have been made up to 2.7 GeV. Resonance couplings have been extracted and compared to previous determinations. With the addition of these cross sections to the world data set, significant changes have occurred in the high-energy behavior of the SAID cross-section predictions and amplitudes.

11 data tables

Differential cross sections for incident photon energies 0.725, 0.775, 0.825and 0.875 GeV.

Differential cross sections for incident photon energies 0.925, 0.975, 1.025and 1.075 GeV.

Differential cross sections for incident photon energies 1.125, 1.175, 1.225and 1.275 GeV.

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Angular Dependence of Polarization of Secondary Protons from the Reaction gamma p --> pi0 p at Photon Energies of 650-MeV and 700-MeV

Zybalov, A.A ; Derebchinsky, A.I. ; Konovalov, O.G. ; et al.
Yad.Fiz. 28 (1978) 105-107, 1978.
Inspire Record 135481 DOI 10.17182/hepdata.18990

None

2 data tables

No description provided.

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Anti-D0 meson production in interactions of neutrons with hydrogen, carbon, and aluminum nuclei at 37.5-GeV to 70-GeV

The BIS-2 collaboration Aleev, A.N. ; Arefev, V.A. ; Balandin, V.P. ; et al.
Phys.Atom.Nucl. 56 (1993) 1235-1240, 1993.
Inspire Record 364824 DOI 10.17182/hepdata.17203

None

6 data tables

No description provided.

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CROSS-SECTION ASYMMETRY OF THE gamma n ---> pi- p REACTION BY POLARIZED PHOTONS IN THE THIRD AND FOURTH RESONANCE REGIONS

Adamian, F.V. ; Akopian, G.G. ; Galumian, P.I. ; et al.
EFI-722-37-84-YEREVAN, 1984.
Inspire Record 206944 DOI 10.17182/hepdata.18433

None

5 data tables

No description provided.

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Compton scattering by the proton through Theta(CMS) = 75-degrees and 90-degrees in the Delta resonance region

Hünger, A ; Peise, J ; Robbiano, A ; et al.
Nucl.Phys.A 620 (1997) 385-416, 1997.
Inspire Record 458618 DOI 10.17182/hepdata.36349

Differential cross sections for Compton scattering by the proton have been measured in the energy interval between 200 and 500 MeV at scattering angles of θ cms = 75° and θ cms = 90° using the CATS, the CATS/TRAJAN, and the COPP setups with the Glasgow Tagger at MAMI (Mainz). The data are compared with predictions from dispersion theory using photo-meson amplitudes from the recent VPI solution SM95. The experiment and the theoretical procedure are described in detail. It is found that the experiment and predictions are in agreement as far as the energy dependence of the differential cross sections in the Δ-range is concerned. However, there is evidence that a scaling down of the resonance part of the M 1+ 3 2 photo-meson amplitude by (2.8 ± 0.9)% is required in comparison with the VPI analysis. The deduced value of the M 1+ 3 2 - photoproduction amplitude at the resonance energy of 320 MeV is: |M 1+ 3 2 | = (39.6 ± 0.4) × 10 −3 m π + −1 .

2 data tables

No description provided.

No description provided.


Deeply virtual and exclusive electroproduction of omega mesons.

The CLAS collaboration Morand, L. ; Dore, D. ; Garcon, M. ; et al.
Eur.Phys.J.A 24 (2005) 445-458, 2005.
Inspire Record 681604 DOI 10.17182/hepdata.43499

The exclusive omega electroproduction off the proton was studied in a large kinematical domain above the nucleon resonance region and for the highest possible photon virtuality (Q2) with the 5.75 GeV beam at CEBAF and the CLAS spectrometer. Cross sections were measured up to large values of the four-momentum transfer (-t < 2.7 GeV2) to the proton. The contributions of the interference terms sigma_TT and sigma_TL to the cross sections, as well as an analysis of the omega spin density matrix, indicate that helicity is not conserved in this process. The t-channel pi0 exchange, or more generally the exchange of the associated Regge trajectory, seems to dominate the reaction gamma* p -> omega p, even for Q2 as large as 5 GeV2. Contributions of handbag diagrams, related to Generalized Parton Distributions in the nucleon, are therefore difficult to extract for this process. Remarkably, the high-t behaviour of the cross sections is nearly Q2-independent, which may be interpreted as a coupling of the photon to a point-like object in this kinematical limit.

85 data tables

Total cross sections and interference terms (TT and TL).

Differential cross sections DSIG/DT for Q**2 = 1.725 GeV**2 and W = 2.77 GeV.

Differential cross sections DSIG/DT for Q**2 = 1.752 GeV**2 and W = 2.48 GeV.

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Differential cross section and recoil polarization measurements for the gamma p to K+ Lambda reaction using CLAS at Jefferson Lab

The CLAS collaboration McCracken, M.E. ; Bellis, M. ; Meyer, C.A. ; et al.
Phys.Rev.C 81 (2010) 025201, 2010.
Inspire Record 840934 DOI 10.17182/hepdata.54967

We present measurements of the differential cross section and Lambda recoil polarization for the gamma p to K+ Lambda reaction made using the CLAS detector at Jefferson Lab. These measurements cover the center-of-mass energy range from 1.62 to 2.84 GeV and a wide range of center-of-mass K+ production angles. Independent analyses were performed using the K+ p pi- and K+ p (missing pi -) final-state topologies/ results from these analyses were found to exhibit good agreement. These differential cross section measurements show excellent agreement with previous CLAS and LEPS results and offer increased precision and a 300 MeV increase in energy coverage. The recoil polarization data agree well with previous results and offer a large increase in precision and a 500 MeV extension in energy range. The increased center-of-mass energy range that these data represent will allow for independent study of non-resonant K+ Lambda photoproduction mechanisms at all production angles.

241 data tables

Differential cross section as a function of COS(THETA(K)) for the centre-of-mass range 1.62-1.63 GeV.

Differential cross section as a function of COS(THETA(K)) for the centre-of-mass range 1.63-1.64 GeV.

Differential cross section as a function of COS(THETA(K)) for the centre-of-mass range 1.64-1.65 GeV.

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Differential cross sections and spin density matrix elements for the reaction $\gamma p \to p \omega$

The CLAS collaboration Williams, M. ; Applegate, D. ; Bellis, M. ; et al.
Phys.Rev.C 80 (2009) 065208, 2009.
Inspire Record 829180 DOI 10.17182/hepdata.52667

High-statistics differential cross sections and spin density matrix elements for the reaction $\gamma p \to p \omega$ have been measured using the CLAS at Jefferson Lab for center-of-mass (CM) energies from threshold up to 2.84 GeV. Results are reported in 112 10-MeV wide CM energy bins, each subdivided into $\cos{\theta_{CM}^{\omega}}$ bins of width 0.1. These are the most precise and extensive $\omega$ photoproduction measurements to date. A number of prominent structures are clearly present in the data. Many of these have not previously been observed due to limited statistics in earlier measurements.

221 data tables

Differential cross section for the W range 1.72 to 1.73 GeV.

Differential cross section for the W range 1.73 to 1.74 GeV.

Differential cross section for the W range 1.74 to 1.75 GeV.

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Differential cross sections for the reactions gamma p-> p eta and gamma p -> p eta-prime

The CLAS collaboration Williams, M. ; Krahn, Z. ; Applegate, D. ; et al.
Phys.Rev.C 80 (2009) 045213, 2009.
Inspire Record 830257 DOI 10.17182/hepdata.52983

High-statistics differential cross sections for the reactions gamma p -> p eta and gamma p -> p eta-prime have been measured using the CLAS at Jefferson Lab for center-of-mass energies from near threshold up to 2.84 GeV. The eta-prime results are the most precise to date and provide the largest energy and angular coverage. The eta measurements extend the energy range of the world's large-angle results by approximately 300 MeV. These new data, in particular the eta-prime measurements, are likely to help constrain the analyses being performed to search for new baryon resonance states.

104 data tables

Differential cross section for the W range 1.68 to 1.69 GeV.

Differential cross section for the W range 1.69 to 1.70 GeV.

Differential cross section for the W range 1.70 to 1.71 GeV.

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Diffractive Phi-meson photoproduction on proton near threshold.

The LEPS collaboration Mibe, T. ; Chang, W.C. ; Nakano, T. ; et al.
Phys.Rev.Lett. 95 (2005) 182001, 2005.
Inspire Record 684863 DOI 10.17182/hepdata.31587

Photoproduction of $\phi$-meson on protons was studied by means of linearly polarized photons at forward angles in the low-energy region from threshold to $E_{\gamma}$= 2.37 GeV. The differential cross sections at $t = -|t|_{min}$ do not increase smoothly as $E_{\gamma}$ increases, but show a local maximum at around 2.0 GeV. The angular distributions demonstrate that $\phi$-mesons are photo-produced predominantly by helicity-conserving processes, and the local maximum is not likely due to unnatural-parity processes.

14 data tables

Differential cross section as a function of T+ABS(TMIN) in the photon energy range 1.57 to 1.67 GeV.

Differential cross section as a function of T+ABS(TMIN) in the photon energy range 1.67 to 1.77 GeV.

Differential cross section as a function of T+ABS(TMIN) in the photon energy range 1.77 to 1.87 GeV.

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