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eta photoproduction on the proton revisited: Evidence for a narrow N(1685) resonance?

Kuznetsov, V. ; Polyakov, M. ; Boiko, T. ; et al.

2007.

Inspire Record 745642 DOI 10.17182/hepdata.41745

Revised analysis of $\Sigma$ beam asymmetry for $\eta$ photoproduction on the free proton reveals a resonant structure at $W\sim 1.69$ GeV. Comparison of experimental data with multipole decomposition based on the E429 solution of the SAID partial wave analysis and including narrow states, suggests a narrow ($\Gamma \leq 15$ MeV) resonance. Possible candidates are $P_{11}$, $P_{13}$, or $D_{13}$ resonances. The result is considered in conjunction with the recent evidence for a bump-like structure at $W\sim 1.67 - 1.68$ GeV in quasi-free $\eta$ photoproduction on the neutron.

5 data tables match query

Table 1

Measured beam asymmetry for a mean scattering angle of 43 degrees.

Table 2

Measured beam asymmetry for a mean scattering angle of 65 degrees.

Table 3

Measured beam asymmetry for a mean scattering angle of 85 degrees.

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ELECTROPRODUCTION OF SINGLE CHARGED PIONS FROM DEUTERIUM AT Q2 APPROXIMATELY 1-GEV2 IN THE RESONANCE REGION

Vapenikova, O. ; Allison, John ; Dickinson, B. ; et al.

Z.Phys.C 37 (1988) 251-258, 1988.

Inspire Record 263398 DOI 10.17182/hepdata.898

We present differential cross-sections for the electro-production of single charged pions from deuterium for a virtual photon mass squared −1.0 GeV2 and for pion nucleon masses in the range 1.23–1.68 GeV (the 1st and 2nd resonance regions). The data are compared with predictions from fits to hydrogen data.

30 data tables match query

Table 1

FORWARD BINS.

Table 2

No description provided.

Table 3

No description provided.

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CROSS-SECTIONS FOR PI- + P ---> N + (K) PI0 (K = 1 TO 5) AND PI- + P ---> N + ETA0 (ETA0 ---> 2 GAMMA) FOR INCIDENT PION MOMENTA BETWEEN 1.3-GEV/C AND 3.8-GEV/C

Crouch, H.R. ; Hargraves, R. ; Lanou, R.E. ; et al.

Phys.Rev.D 21 (1980) 3023-3058, 1980.

Inspire Record 158169 DOI 10.17182/hepdata.4334

This paper presents the results of a study of the dominant neutral final states from π−p interactions. The data were obtained in an experiment performed at the Brookhaven National Laboratory Alternating Gradient Synchrotron, using a set of steel-plate optical spark chambers surrounding a liquid-hydrogen target. We present differential and total cross sections for the reactions (1) π−p→n+π0 and (2) π−p→n+η0(η0→2γ) and total cross sections for the reactions (3) π−p→n+kπ0 (k=2, 3, 4, and 5) and (4) π−p→all neutrals for eighteen values of beam momentum in the interval 1.3 to 4.0 GeV/c. The angular distributions for (1) and (2) have been analyzed in terms of expansions in Legendre polynomials, the coefficients for which are also given.

41 data tables match query

Table 1

No description provided.

Table 2

SIG = 4*PI*LEG(L=0).

Table 3

FORWARD DIFFERENTIAL CROSS SECTION CALCULATED FROM LEGENDRE POLYNOMIAL COEFFICIENTS AND ERROR MATRICES.

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Coincidence electroproduction of single neutral pions in the resonance region at q 2 = 0.5 (GeV/ c ) 2

Latham, A. ; Allison, J. ; Booth, I. ; et al.

Nucl.Phys.B 156 (1979) 58-92, 1979.

Inspire Record 1392686 DOI 10.17182/hepdata.836

Data are presented for the reaction ep → ep π 0 at a nominal four-momentum transfer squared of 0.5 (GeV/ c ) 2 . The data were obtained using an extracted electron beam from NINA and two magnetic spectrometers for coincidence detection of the electron and proton. Details are given of the experimental method and the results are given for isobar masses in the range 1.19 – 1.73 GeV/ c 2 .

21 data tables match query

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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K- p Charge Exchange and Hyperon Production Cross-Sections from 860-MeV/c to 1000-MeV/c

Jones, M. ; Levi Setti, R. ; Merrill, D. ; et al.

Nucl.Phys.B 90 (1975) 349-383, 1975.

Inspire Record 91346 DOI 10.17182/hepdata.6742

The K − p reactions leading to charge exchange and hyperon final states have been studied at nine momenta between 862 and 1001 MeV/ c using data from a 600 000 picture exposure of the Lawrence Berkeley Laboratory 25″ liquid hydrogen bubble chamber. Partial cross sections are determined for all final states resolved by kinematic fitting. In addition, differential cross sections are presented for the two-body final states K o n , Λπ o and Σ +- π -+ along with hyperon polarization angular distributions for Λπ o and Σ + π − .

60 data tables match query

Table 2

No description provided.

Table 3

No description provided.

Table 4

No description provided.

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Single pi+ electroproduction on the proton in the first and second resonance regions at 0.25-GeV2 < Q2 < 0.65-GeV**2 using CLAS.

The CLAS collaboration Egiyan, H. ; Aznauryan, I.G. ; Burkert, V.D. ; et al.

Phys.Rev.C 73 (2006) 025204, 2006.

Inspire Record 707883 DOI 10.17182/hepdata.6748

The ep -> e'pi^+n reaction was studied in the first and second nucleon resonance regions in the 0.25 GeV^2 < Q^2 < 0.65 GeV^2 range using the CLAS detector at Thomas Jefferson National Accelerator Facility. For the first time the absolute cross sections were measured covering nearly the full angular range in the hadronic center-of-mass frame. The structure functions sigma_TL, sigma_TT and the linear combination sigma_T+epsilon*sigma_L were extracted by fitting the phi-dependence of the measured cross sections, and were compared to the MAID and Sato-Lee models.

345 data tables match query

Table 1

Structure functions for Q**2 = 0.30 GeV**2 and W = 1.11 GeV.

Table 2

Structure functions for Q**2 = 0.30 GeV**2 and W = 1.13 GeV.

Table 3

Structure functions for Q**2 = 0.30 GeV**2 and W = 1.15 GeV.

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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.

469 data tables match query

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.

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Study of photoproduction on hydrogen in a streamer chamber with tagged photons for 1.6 GeV $ < E_\gamma <$ 6.3 GeV Topological and reaction cross sections

The Aachen-Hamburg-Heidelberg-Munich collaboration Struczinski, W. ; Dittmann, P. ; Eckardt, V. ; et al.

Nucl.Phys.B 108 (1976) 45-74, 1976.

Inspire Record 100089 DOI 10.17182/hepdata.35779

We have studied photoproduction using a 1 m streamer chamber at DESY and a tagged photon beam with an energy range of 1.6 GeV < E γ < 6.3 GeV. We analysed approximately 30 000 events and report topological, channel and resonance production cross sections for a large number of reactions with three and five outgoing charged particles.

28 data tables match query

Table 2

'PARAMETRIZATION'.

Table 3

'INTERFERENCE'.

Table 4

'PARAMETRIZATION'.

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Further analysis of anti-p p ---> 3pi0, eta eta pi0 and eta pi0 pi0 at rest

Abele, A. ; Adomeit, J. ; Armstrong, D.S. ; et al.

Nucl.Phys.A 609 (1996) 562-584, 1996.

Inspire Record 431685 DOI 10.17182/hepdata.36492

A fresh analysis is reported of high statistics Crystal Barrel data on p p → 3π 0 , ηηπ 0 , ηπ 0 π 0 and ηη ′ π 0 at rest. This analysis is made fully consistent with CERN-Munich data on π + π − → π + π − up to a mass of 1900 MeV, with GAMS data on π + π − → π 0 π 0 , and with BNL and ANL data on π + π − → K K , which are fitted simultaneously. There is evidence for an I = 0, J PC = 2 ++ resonance with weak (≤ 7%) coupling to ππ, strong coupling to both ϱϱ and ωω and pole position 1534 - i90 MeV. This resonance agrees qualitatively with GAMS and VES data on ππ → ωω, previously interpreted in terms of a resonance at 1590–1640 MeV. New masses and widths for (A) ƒ 0 (1370) and (B) ƒ 0 (1500) , fitted to all eight data sets, are M A = 1300 ± 15 Mev, Γ A = 230 ± 15 MeV, M B = 1500 ± 8 MeV, Γ B = 132 ± 15 MeV. Branching ratios to ππ and ηη are given, and differ significantly from earlier determinations because of a new procedure.

0 data tables match query

rivet Analysis
Measurement of the Reaction $e^+ e^- \to \eta \pi^+ \pi^-$ in the Center-of-mass Energy Interval 1350-{MeV} to 2400-{MeV}

The DM2 collaboration Antonelli, A. ; Baldini, R. ; Calcaterra, A. ; et al.

Phys.Lett.B 212 (1988) 133-138, 1988.

Inspire Record 264144 DOI 10.17182/hepdata.29912

The e + e − → ηπ + π − reaction has been measured in the center of mass energy interval 1350–2400 MeV by the magnetic detector DM2 at the Orsay storage ring DCI. Under the hypothesis of only one large resonance the cross section is not fit in a satisfactory way. The branching ratio τ − → η − π 0 ν τ =(0.13 ± 0.02)% is deduced via CVC from the above measurement.

1 data table match query

Table 1

No description provided.

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eta photoproduction on the proton revisited: Evidence for a narrow N(1685) resonance?

ELECTROPRODUCTION OF SINGLE CHARGED PIONS FROM DEUTERIUM AT Q2 APPROXIMATELY 1-GEV2 IN THE RESONANCE REGION

CROSS-SECTIONS FOR PI- + P ---> N + (K) PI0 (K = 1 TO 5) AND PI- + P ---> N + ETA0 (ETA0 ---> 2 GAMMA) FOR INCIDENT PION MOMENTA BETWEEN 1.3-GEV/C AND 3.8-GEV/C

Coincidence electroproduction of single neutral pions in the resonance region at q 2 = 0.5 (GeV/ c ) 2

K- p Charge Exchange and Hyperon Production Cross-Sections from 860-MeV/c to 1000-MeV/c

Single pi+ electroproduction on the proton in the first and second resonance regions at 0.25-GeV2 < Q2 < 0.65-GeV**2 using CLAS.

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

Study of photoproduction on hydrogen in a streamer chamber with tagged photons for 1.6 GeV $ < E_\gamma <$ 6.3 GeV Topological and reaction cross sections

Further analysis of anti-p p ---> 3pi0, eta eta pi0 and eta pi0 pi0 at rest

rivet Analysis
Measurement of the Reaction $e^+ e^- \to \eta \pi^+ \pi^-$ in the Center-of-mass Energy Interval 1350-{MeV} to 2400-{MeV}