Compton scattering cross section on the proton at high momentum transfer.

The Hall A collaboration Danagoulian, A. ; Mamyan, V.H. ; Roedelbronn, M. ; et al.
Phys.Rev.Lett. 98 (2007) 152001, 2007.
Inspire Record 743383 DOI 10.17182/hepdata.31472

Cross-section values for Compton scattering on the proton were measured at 25 kinematic settings over the range s = 5-11 and -t = 2-7 GeV2 with statistical accuracy of a few percent. The scaling power for the s-dependence of the cross section at fixed center of mass angle was found to be 8.0 +/ 0.2, strongly inconsistent with the prediction of perturbative QCD. The observed cross-section values are in fair agreement with the calculations using the handbag mechanism, in which the external photons couple to a single quark.

4 data tables

Cross section of proton Compton Scattering at centre of mass energy squared of 4.82 GeV.

Cross section of proton Compton Scattering at centre of mass energy squared of 6.79 GeV.

Cross section of proton Compton Scattering at centre of mass energy squared of 8.90 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.


Precision Measurements of the Anti-proton - Proton Elastic Scattering Cross-section at 90-degrees in the Incident Momentum Range Between 3.5-{GeV}/$c$ and 5.7-{GeV}/$c$

The R704 collaboration Baglin, C. ; Baird, S. ; Bassompierre, G. ; et al.
Phys.Lett.B 225 (1989) 296-300, 1989.
Inspire Record 278760 DOI 10.17182/hepdata.29802

The high antiproton-proton luminosity obtained by using a target system consisting of a hydrogen gas-jet crossing a coasting beam of cooled antiproton circulating in one of the rings of CERN's ISR provides the possibility to measure low cross section reactions with very high precision. We present measurements of the antiproton-proton elastic cross section at 90° CM at incident momenta between 3.5 GeV/ c and 5.7 GeV/ c . The precision of these measurements is much higher than previously reported results. The data show that the cross section of this reaction decreases faster than s −12 over this momentum range.

2 data tables

No description provided.

No description provided.


Charged Meson Pair Production in $\gamma \gamma$ Interactions

Boyer, J. ; Burke, D.L. ; Butler, F. ; et al.
Phys.Rev.Lett. 56 (1986) 207, 1986.
Inspire Record 220003 DOI 10.17182/hepdata.20236

The cross section for the production of π+π− or K+K− pairs in γγ interactions is measured for mππ between 1.7 and 3.5 GeV/c2 and for two intervals of γγ center-of-mass scattering angle. Results are compared with predictions of a QCD model.

2 data tables

Data read off graph.

Data read off graph.


A MEASUREMENT OF THE K0(L) p ELASTIC CROSS-SECTION FOR 3 less than or equal to p less than or equal to 13-GeV/c AND .1 less than or equal to |t| less than or equal to 1.3-GeV**2

Cittolin, S. ; Gasparini, F. ; Limentani, S. ; et al.
Nucl.Phys.B 157 (1979) 197-211, 1979.
Inspire Record 7663 DOI 10.17182/hepdata.34662

The cross section for the K L 0 p elastic scattering has been measured for the first time. The incident momentum and momentum transfer ranges are 3 ⩽ p ⩽ 13 GeV/ c , 0.1 ⩽ | t | ⩽ 1.3 GeV 2 . The results are compared to those of other experiments related to ours by isotopic spin conservation, finding agreement with some and discrepancies with others. The differential cross sections have been parametrized in the form A e bt . The coefficients show little or no dependence on energy, with A ≅ 9.8 mb · GeV −2 and b ≅ 4.7 GeV −2 . The effective linear trajectory has been determined and gives α 0 = 0.95 ± 0.15, α ′ = −0.35 ± 0.48 GeV −2 , in good agreement with dominance by pomeron exchange.

3 data tables

CROSS SECTIONS DEDUCED FROM THE 46 PCT OF EVENTS WHICH YIELD UNIQUE SOLUTIONS.

<RAW> CROSS SECTIONS DEDUCED FROM A STATISTICAL TREATMENT OF ALL EVENTS.

<SMOOTHED> CROSS SECTIONS DEDUCED FROM A STATISTICAL TREATMENT OF ALL EVENTS.


Experimental Confirmation of the 1100 Structure and First Observation of the Leptonic Decay of the $\rho^\prime$ (1250)

Bartalucci, S. ; Basini, G. ; Bertolucci, S. ; et al.
Nuovo Cim.A 49 (1979) 207, 1979.
Inspire Record 131639 DOI 10.17182/hepdata.37533

We have extended our survey of the reaction γ+p→p+e++e− by collecting 20 000 additional e+e− pairs in the invariant-mass region 900<m<1500 MeV. The measured interference pattern shows two enhancements at mass values of 1097 and 1266 MeV. The parameters of those structure, when interpreted as vector mesons in the VDM framework, are given.

1 data table

No description provided.


A MEASUREMENT OF THE K0(L) p ---> K0(S) p REACTION BETWEEN 4-GeV/c AND 14-GeV/c IN THE RANGE .1-GeV**2 less than or equal to t is less than or equal to 2-GeV**2

Cittolin, S. ; Gasparini, F. ; Goldin, M. ; et al.
Nucl.Phys.B 142 (1978) 410-444, 1978.
Inspire Record 6510 DOI 10.17182/hepdata.34941

We present experimental data on the K L 0 p → K S 0 p reaction between 4 and 14 GeV/ c in the range 0.1 ≲ | t | ≲ 2 GeV 2 . This experiment has been performed at the CERN PS, using spark chambers and a large aperture magnet. The results show a break of slope at t = −0.3 GeV 2 . The ω trajectory deduced from the data has an intercept α (0) = 0.5 and a slope α ′ = 0.88. A comparison with various models shows that the non-flip amplitude is dominant.

1 data table

No description provided.


Rho Production by Virtual Photons

Joos, P. ; Ladage, A. ; Meyer, H. ; et al.
Nucl.Phys.B 113 (1976) 53-92, 1976.
Inspire Record 108749 DOI 10.17182/hepdata.35708

The reaction γ V p → p π + π − was studied in the W , Q 2 region 1.3–2.8 GeV, 0.3–1.4 GeV 2 using the streamer chamber at DESY. A detailed analysis of rho production via γ V p→ ϱ 0 p is presented. Near threshold rho production has peripheral and non-peripheral contributions of comparable magnitude. At higher energies ( W > 2 GeV) the peripheral component is dominant. The Q 2 dependence of σ ( γ V p→ ϱ 0 p) follows that of the rho propagator as predicted by VDM. The slope of d σ /d t at 〈 Q 2 〉 = 0.4 and 0.8 GeV 2 is within errors equal to its value at Q 2 = 0. The overall shape of the ϱ 0 is t dependent as in photoproduction, but is independent of Q 2 . The decay angular distribution shows that longitudinal rhos dominate in the threshold region. At higher energies transverse rhos are dominant. Rho production by transverse photons proceeds almost exclusively by natural parity exchange, σ T N ⩾ (0.83 ± 0.06) σ T for 2.2 < W < 2.8 GeV. The s -channel helicity-flip amplitudes are small compared to non-flip amplitudes. The ratio R = σ L / σ T was determined assuming s -channel helicity conservation. We find R = ξ 2 Q 2 / M ϱ 2 with ξ 2 ≈ 0.4 for 〈 W 〉 = 2.45 GeV. Interference between rho production amplitudes from longitudinal and transverse photons is observed. With increasing energy the phase between the two amplitudes decreases. The observed features of rho electroproduction are consistent with a dominantly diffractive production mechanism for W > 2 GeV.

10 data tables

DIPION CHANNEL CROSS SECTION.

THE TOTAL CROSS SECTION WAS OBTAINED BY THE AUTHORS FROM A FIT TO THE SINGLE ARM DATA OF S. STEIN ET AL., PR D12, 1884 (1975).

No description provided.

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Measurement of the double-charge-exchange reactions pi- p ---> k+ sigma- and k- p ---> pi+ sigma -

Akerlof, C.W. ; Caldwell, P.K. ; Coffin, C.T. ; et al.
Phys.Rev.Lett. 27 (1971) 539-542, 1971.
Inspire Record 68930 DOI 10.17182/hepdata.21463

The forward cross sections for the reactions π−p→K+Σ− and K−p→π+Σ− have been determined for incident particle momenta in the range of 2.75 to 3.50 GeV/c, and an upper limit was established at 5.00 GeV/c. These measurements show that the double-charge-exchange process π−p→K+Σ− is suppressed by a factor of 1500 at 3 GeV/c relative to the single-exchange reaction π+p→K+Σ+.

2 data tables

No description provided.

No description provided.


MEASUREMENT OF THE RATIO OF THE PROTON FORM-FACTORS, G(E) / G(M), AT HIGH MOMENTUM TRANSFERS AND THE QUESTION OF SCALING

Litt, J. ; Buschhorn, G. ; Coward, D.H. ; et al.
Phys.Lett.B 31 (1970) 40-44, 1970.
Inspire Record 54895 DOI 10.17182/hepdata.28767

Electron-proton elastic scattering cross sections have been measured at the Stanford Linear Accelerator Center at four-momentum transfers squared (q 2 ) of 1.0, 1.5, 2.0, 2.5and 3.75 (GeV/ c ) 2 . The angular distributions at q 2 = 2.5 and 3.75 (GeV/ c ) 2 are sufficient to provide values of the ratio G E / G M independent of the results from other laboratories. Our results are compatible with scaling, G E (q 2 ) = G M (q 2 )/ μ , within the experimental errors.

6 data tables

No description provided.

No description provided.

No description provided.

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