Anton, G.
Single Differential Cross Section
[1.959]
Max results
Sort by Reverse order

Showing 10 of 48 results

$K^+$ nucleon elastic scattering at 180° between 1.0 and 1.5 GeV/c incident momentum

Adams, U. ; Carter, R.S. ; Cook, V. ; et al.
Nucl.Phys.B 87 (1975) 41-51, 1975.
Inspire Record 1392682 DOI 10.17182/hepdata.32061

We have measured the cross section at 180° for K + p and K + n elastic scattering in the momentum range 1.0 to 1.5 GeV/ c . The K + n cross section was measured on deuterium and the K + p on hydrogen and deuterium. We were thus able to measure directly the difference between free nucleon (proton) scattering and bound nucleon (proton) scattering at large angles. This difference was found to be small and within our experimental accuracy the K + p(n) cross section should be equal to the K + p (free) cross section at 180°. We found no evidence for an s -channel resonance Z ∗ in either the K + p or K + n system. A comparison of our data and those of other groups with theoretical predictions is given.

2 data tables
Table 1

DEUTERIUM TARGET. U IS ABOUT 0.1 GEV**2.

Table 2

HYDROGEN AND DEUTERIUM TARGET DATA ARE IN GOOD AGREEMENT. THESE CROSS SECTIONS ARE A WEIGHTED AVERAGE.


Elastic Electron-Proton Scattering at Momentum Transfers up to 110 Fermi$^−^2$

Behrend, H.J. ; Brasse, F.W. ; Engler, J. ; et al.
Nuovo Cim.A 48 (1967) 140-164, 1967.
Inspire Record 1185336 DOI 10.17182/hepdata.1060

Using the internal beam of DESY elastic electron-proton cross-sections were measured at various angles between 32° and 130°, and with momentum transfers ofq 2=39, 60, 80 and 110 fm−2. Two single-quadrupole spectrometers, movable around a common liquid-hydrogen target, were used for analysing the momentum of the scattered electrons. Čerenkov and shower counters discriminated against pion and low-energy background. As a cross-section reference, recoil protons from elastic scattering atq 2=10 fm−2 were used, with a quantameter serving as an intermediate monitor. The data are consistent with the Rosenbluth formula, giving real form factorsG E andG M . Both continue to decrease with increasing momentum transfer, but somewhat faster than indicated by measurements performed so far.

9 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

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
Table 1

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

Table 2

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

Table 3

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

More…

$\pi^+$ 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
Table 1

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

Table 2

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

Table 3

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

More…

Study of the reaction $\gamma p\to p\pi^0\eta$

The CB-ELSA collaboration Horn, I. ; Anisovich, A.V. ; Anton, G. ; et al.
Eur.Phys.J.A 38 (2008) 173-186, 2008.
Inspire Record 789175 DOI 10.17182/hepdata.54384

The reaction $\gamma p\to p\pi^0\eta$ has been studied with the CBELSA detector at the tagged photon beam of the Bonn electron stretcher facility. The reaction shows contributions from $\Delta^+(1232)\eta$, $N(1535)^+\pi^0$ and $pa_0(980)$ as intermediate states. A partial wave analysis suggests that the reaction proceeds via formation of six $\Delta$ resonances, $\Delta(1600)P_{33}$, $\Delta(1920)P_{33}$, $\Delta(1700)D_{33}$, $\Delta(1940)D_{33}$, $\Delta(1905)F_{35}$, $\Delta(2360)D_{33}$, and two nucleon resonances $N(1880)P_{11}$ and $N(2200)P_{13}$, for which pole positions and decay branching ratios are given.

7 data tables
Table 1

Total cross section for GAMMA P --> P PI0 ETA.

Table 2

Differential cross sections as a function of the angles of the individual final state particles for the W range 1.7 to 1.9 GeV.. Errors shown are statistical only.

Table 3

Differential cross sections as a function of the angles of the individual final state particles for the W range 1.9 to 2.1 GeV.. Errors shown are statistical only.

More…

High-statistics measurement of neutral pion-pair production in two-photon collisions

The Belle collaboration Uehara, S. ; Watanabe, Y. ; Adachi, I. ; et al.
Phys.Rev.D 78 (2008) 052004, 2008.
Inspire Record 786406 DOI 10.17182/hepdata.50151

We report a high-statistics measurement of differential cross sections for the process gamma gamma -> pi^0 pi^0 in the kinematic range 0.6 GeV <= W <= 4.0 GeV and |cos theta*| <= 0.8, where W and theta* are the energy and pion scattering angle, respectively, in the gamma gamma center-of-mass system. Differential cross sections are fitted to obtain information on S, D_0, D_2, G_0 and G_2 waves. The G waves are important above W ~= 1.6 GeV. For W <= 1.6 GeV the D_2 wave is dominated by the f_2(1270) resonance while the S wave requires at least one additional resonance besides the f_0(980), which may be the f_0(1370) or f_0(1500). The differential cross sections are fitted with a simple parameterization to determine the parameters (the mass, total width and Gamma_{gamma gamma}B(f_0 -> pi^0 pi^0)) of this scalar meson as well as the f_0(980). The helicity 0 fraction of the f_2(1270) meson, taking into account interference for the first time, is also obtained.

29 data tables
Table 1

Differential cross section for W = 0.61, 0.63 and 0.65 GeV.

Table 2

Differential cross section for W = 0.67, 0.69 and 0.71 GeV.

Table 3

Differential cross section for W = 0.73, 0.75 and 0.77 GeV.

More…

Photoproduction of pi0 omega off protons for E(gamma) < 3-GeV.

The CB-ELSA collaboration Junkersfeld, J. ; Anisovich, A.V. ; Anton, G. ; et al.
Eur.Phys.J.A 31 (2007) 365-372, 2007.
Inspire Record 748502 DOI 10.17182/hepdata.43511

Differential and total cross-sections for photoproduction of gamma proton to proton pi0 omega and gamma proton to Delta+ omega were determined from measurements of the CB-ELSA experiment, performed at the electron accelerator ELSA in Bonn. The measurements covered the photon energy range from the production threshold up to 3GeV.

18 data tables
Table 1

Differential cross section as a function of the OMEGA angle.

Table 2

Differential cross section as a function of the OMEGA angle.

Table 3

Differential cross section as a function of the PI0 angle.

More…

Separated structure functions for the exclusive electroproduction of K+ Lambda and K+ Sigma0 final states.

The CLAS collaboration Ambrozewicz, P. ; Carman, D.S. ; Feuerbach, R.J. ; et al.
Phys.Rev.C 75 (2007) 045203, 2007.
Inspire Record 732363 DOI 10.17182/hepdata.4994

We report measurements of the exclusive electroproduction of $K^+\Lambda$ and $K^+\Sigma^0$ final states from a proton target using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The separated structure functions $\sigma_T$, $\sigma_L$, $\sigma_{TT}$, and $\sigma_{LT}$ were extracted from the $\Phi$- and $\epsilon$-dependent differential cross sections taken with electron beam energies of 2.567, 4.056, and 4.247 GeV. This analysis represents the first $\sigma_L/\sigma_T$ separation with the CLAS detector, and the first measurement of the kaon electroproduction structure functions away from parallel kinematics. The data span a broad range of momentum transfers from $0.5\leq Q^2\leq 2.8$ GeV$^2$ and invariant energy from $1.6\leq W\leq 2.4$ GeV, while spanning nearly the full center-of-mass angular range of the kaon. The separated structure functions reveal clear differences between the production dynamics for the $\Lambda$ and $\Sigma^0$ hyperons. These results provide an unprecedented data sample with which to constrain current and future models for the associated production of strangeness, which will allow for a better understanding of the underlying resonant and non-resonant contributions to hyperon production.

531 data tables
Table 1

Cross sections for incident energy 2.567 GeV for the Q**2 range 0.5 to 0.8 GeV**2 and W range 1.6 to 1.7 GeV.

Table 2

Cross sections for incident energy 2.567 GeV for the Q**2 range 0.5 to 0.8 GeV**2 and W range 1.70 to 1.75 GeV.

Table 3

Cross sections for incident energy 2.567 GeV for the Q**2 range 0.5 to 0.8 GeV**2 and W range 1.75 to 1.80 GeV.

More…

eta' photoproduction on the proton for photon energies from 1.527-GeV to 2.227-GeV.

The CLAS collaboration Dugger, M. ; Ball, J.P. ; Collins, P. ; et al.
Phys.Rev.Lett. 96 (2006) 062001, 2006.
Inspire Record 700399 DOI 10.17182/hepdata.31553

Differential cross sections for the reaction gamma p -> eta-prime p have been measured with the CLAS spectrometer and a tagged photon beam with energies from 1.527 to 2.227 GeV. The results reported here possess much greater accuracy than previous measurements. Analyses of these data indicate for the first time the coupling of the etaprime N channel to both the S_11(1535) and P_11(1710) resonances, known to couple strongly to the eta N channel in photoproduction on the proton, and the importance of j=3/2 resonances in the process.

5 data tables
Table 1

Differential cross sections for ETAPRIME photoproduction on the proton at photon energies 1.527, 1.577 and 1.627 GeV. The errors shown are combined statistical and systematic.

Table 2

Differential cross sections for ETAPRIME photoproduction on the proton at photon energies 1.677, 1.728 and 1.779 GeV. The errors shown are combined statistical and systematic.

Table 3

Differential cross sections for ETAPRIME photoproduction on the proton at photon energies 1.829, 1.879 and 1.930 GeV. The errors shown are combined statistical and systematic.

More…

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
Table 1

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

Table 2

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

Table 3

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

More…