Donahue, J.
nucl-ex
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Fast neutron production (p(n) >= 1-GeV/c) in p p and p C-12 interactions at p = 4.2-GeV/c and 10-GeV/c.

Bekmirzaev, R.N. ; Grishin, V.G. ; Grishina, O.V. ; et al.
Sov.J.Nucl.Phys. 49 (1989) 637-639, 1989.
Inspire Record 253442 DOI 10.17182/hepdata.9459

None

5 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Five-pion final state in p p annihilations at 0.70 to 1.1 GeV/c

Burns, R.R. ; Condon, P.E. ; Donahue, J. ; et al.
Nucl.Phys.B 85 (1975) 337-353, 1975.
Inspire Record 1392678 DOI 10.17182/hepdata.32116

Results are reported on the reaction p p → π + π + π − π − π 0 at six lab momenta spanning the region from 0.686 to 1.098 GeV/ c . The cross section for this process drops from 20.3 ± 1.2 mb at 0.686 GeV/ c to 13 1.0 mb at 1.098 GeV/ c . Resonance production is determined by means of a model which includes Bose symmetrization, Breit-Wigner amplitudes and Bose-Einstein correlations for the like-charged pion pairs in the nonresonant part of the amplitude. The likelihood fit to the resonance channels yields about 0.8% ηππ , 12% ϱ ± πππ , 2% f πππ , 8% ω ππ , 22% ϱ ± ϱ 0 π , 13% ωϱ 0 and 9% ω f with errors on the order of a few percent. Several percent A 1 ± ππ and X(1440) π were also needed to obtain good fits. The ϱ 0 πππ and ϱ 0 ϱ 0 π channels as well as A 2 ππ and A 1 0 ππ are consistent with zero. Reasonable fits to the mass distributions are obtained. Production angular distributions are found to be essentially uniform. The angular correlations between pion pairs are approximately fit by the simple model of resonance production with Bose symmetrization.

2 data tables
Table 1

Axis error includes +- 0.0/0.0 contribution.

Table 2

Axis error includes +- 0.0/0.0 contribution.


Analysis of $\bar{p}p\to K^+ K^- \pi^+ \pi^-$ around 1 GeV/c

Price, L.R. ; Burns, R.R. ; Condon, P.E. ; et al.
Nucl.Phys.B 85 (1975) 326-336, 1975.
Inspire Record 1392681 DOI 10.17182/hepdata.32088

Approximately 100 000 four-prong antiproton annihilations in hydrogen were measured. A clean, unbiased sample of 842 K + K − π + π − events was obtained. This reaction is dominated by K ∗ (∼45%) and ϱ 0 (∼20%) production, with smaller amounts of A 2 0 (∼15%) and ϕ (∼5%) production. 25% of the reactions involved double resonance production. No significant three-body resonance production is observed.

1 data table
Table 1

ERRORS INCLUDE SYSTEMATICS.


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.

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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
Table 1

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

Table 2

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

Table 3

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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Cross sections and Rosenbluth separations in 1H(e, e'K+)Lambda up to Q2=2.35 GeV2

The Jefferson Lab Hall A collaboration Coman, M. ; Markowitz, P. ; Aniol, K.A. ; et al.
Phys.Rev.C 81 (2010) 052201, 2010.
Inspire Record 837422 DOI 10.17182/hepdata.54197

The kaon electroproduction reaction 1H(e,e'K+)Lambda was studied as a function of the virtual-photon four-momentum, Q2, total energy, W, and momentum transfer, t, for different values of the virtual- photon polarization parameter. Data were taken at electron beam energies ranging from 3.40 to 5.75 GeV. The center of mass cross section was determined for 21 kinematics corresponding to Q2 of 1.90 and 2.35 GeV2 and the longitudinal, sigmaL, and transverse, sigmaT, cross sections were separated using the Rosenbluth technique at fixed W and t. The separated cross sections reveal a flat energy dependence at forward kaon angles not satisfactorily described by existing electroproduction models. Influence of the kaon pole on the cross sections was investigated by adopting an off-shell form factor in the Regge model which better describes the observed energy dependence of sigmaT and sigmaL.

11 data tables
Table 1

Measured values of the separated cross section at Q**2 = 2.35 GeV**2 and W = 1.85 GeV.. Errors contain both statistics and systematics.

Table 2

Measured values of the separated cross section at Q**2 = 1.90 GeV**2.. Errors contain both statistics and systematics.

Table 3

Measured values of the separated cross section at Q**2 = 2.35 GeV**2.. Errors contain both statistics and systematics.

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Photoproduction of $\eta$ and $\eta\prime$ Mesons off Protons

The CBELSA/TAPS collaboration Crede, V. ; McVeigh, A. ; Anisovich, A.V. ; et al.
Phys.Rev.C 80 (2009) 055202, 2009.
Inspire Record 836340 DOI 10.17182/hepdata.53229

Total and differential cross sections for $\eta$ and $\eta ^\prime$ photoproduction off the proton have been determined with the CBELSA/TAPS detector for photon energies between 0.85 and 2.55 GeV. The $\eta$ mesons are detected in their two neutral decay modes, $\eta\to\gamma\gamma$ and $\eta\to 3\pi^0\to 6\gamma$, and for the first time, cover the full angular range in $\rm cos \theta_{cm}$ of the $\eta$ meson. These new $\eta$ photoproduction data are consistent with the earlier CB-ELSA results. The $\eta ^\prime$ mesons are observed in their neutral decay to $\pi^0\pi^0\eta\to 6\gamma$ and also extend the coverage in angular range.

56 data tables
Table 1

Differential cross section for ETA production at incident photon energy 0.850 to 0.900 GeV.

Table 2

Differential cross section for ETA production at incident photon energy 0.900 to 0.950 GeV.

Table 3

Differential cross section for ETA production at incident photon energy 0.950 to 1.000 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
Table 1

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

Table 2

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

Table 3

Differential cross section for the W range 1.70 to 1.71 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
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.

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Electroproduction of $\phi(1020)$ mesons at $1.4\leq Q^2\leq$ 3.8 GeV$^2$ measured with the CLAS spectrometer

The CLAS collaboration Santoro, J.P. ; Smith, E.S. ; Garc con, M. ; et al.
Phys.Rev.C 78 (2008) 025210, 2008.
Inspire Record 781974 DOI 10.17182/hepdata.50913

Electroproduction of exclusive $\phi$ vector mesons has been studied with the CLAS detector in the kinematical range $1.6\leq Q^2\leq 3.8$ GeV$^{2}$, $0.0\leq t^{\prime}\leq 3.6$ GeV$^{2}$, and $2.0\leq W\leq 3.0$ GeV. The scaling exponent for the total cross section as $1/(Q^2+M_{\phi}^2)^n$ was determined to be $n=2.49\pm 0.33$. The slope of the four-momentum transfer $t'$ distribution is $b_{\phi}=0.98 \pm 0.17$ GeV$^{-2}$. The data are consistent with the assumption of s-channel helicity conservation (SCHC). Under this assumption, we determine the ratio of longitudinal to transverse cross sections to be $R=0.86 \pm 0.24$. A 2-gluon exchange model is able to reproduce the main features of the data.

5 data tables
Table 1

Axis error includes +- 18.6/18.6 contribution.

Table 2

Axis error includes +- 18.6/18.6 contribution.

Table 3

Axis error includes +- 18.6/18.6 contribution.

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