Lamb, R.C.
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DSIG/DT
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Elastic photoproduction of J/psi and Upsilon mesons at HERA.

The H1 collaboration Adloff, C. ; Andreev, V. ; Andrieu, B. ; et al.
Phys.Lett.B 483 (2000) 23-35, 2000.
Inspire Record 525022 DOI 10.17182/hepdata.46894

Cross sections for elastic photoproduction of J/Psi and Upsilon mesons are presented. For J/Psi mesons the dependence on the photon-proton centre-of-mass energy W_gammap is analysed in an extended range with respect to previous measurements of 26<=W_gammap<= 285 GeV. The measured energy dependence is parameterized as sigma_gammap proportional W_gammap^delta with delta=0.83+-0.07. The differential cross section dsigma/dt for J/Psi mesons is derived, its dependence on W_gammap and on t is analysed and the effective trajectory (in terms of Regge theory) is determined to be alpha(t)=(1.27+-0.05)+(0.08+-0.17)*t/GeV^2. Models based on perturbative QCD and on pomeron exchange are compared to the data.

5 data tables
Table 1

The cross sections for the elastic photoproduction of J/PSI particles.

Table 2

Differential cross section, DSIG/DT, for the elastic photoproduction of J/PSI particles.

Table 3

The slope of the DSIG/DT distribution.

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Measurement of small angle anti-proton - proton elastic scattering at S**(1/2) = 546-GeV and 1800-GeV

The CDF collaboration Abe, F. ; Albrow, Michael G. ; Amidei, Dante E. ; et al.
Phys.Rev.D 50 (1994) 5518-5534, 1994.
Inspire Record 359411 DOI 10.17182/hepdata.22369

Antiproton-proton elastic scattering was measured at c.m.s. energies √s =546 and 1800 GeV in the range of four-momentum transfer squared 0.025<-t<0.29 GeV2. The data are well described by the exponential form ebt with a slope b=15.28±0.58 (16.98±0.25) GeV−2 at √s =546 (1800) GeV. The elastic scattering cross sections are, respectively, σel=12.87±0.30 and 19.70±0.85 mb.

4 data tables
Table 1

Final results (systematic errors included).

Table 2

Final results (systematic errors included).

Table 3

Statistical errors only. Data supplied by S. Belforte.

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Photoproduction of $\phi$ Mesons by Linearly Polarized Photons of Energy 20-{GeV} to 40-{GeV} and Further Evidence for a Photoproduced High Mass $K K$ Enhancement

The Omega Photon collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.
Z.Phys.C 27 (1985) 233, 1985.
Inspire Record 204590 DOI 10.17182/hepdata.16067

A study of ϕ-meson photoproduction by partially polarized photons of energy 20–40 GeV is reported. The production mechanism is found to conserves-channel helicity and to proceed via natural-parity exchange in thet channel. In the photoproduction of high-massK+K− states with photons of energy 20–70 GeV, there is evidence for an enhancement at a mass of 1.76 GeV with width 0.08 GeV.

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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The $\rho^\prime$ (1600) in the Reaction $\gamma p \to \pi^+ \pi^- \pi^0 \pi^0 p$ at Photon Energies of 20-{GeV} to 70-{GeV}

The Omega Photon collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.
Z.Phys.C 26 (1985) 499, 1985.
Inspire Record 202941 DOI 10.17182/hepdata.15774

The reactionγp→π+π−π0π0p (excludingωπ0 production) has been studied for photon energies in the range 20–70 GeV. A peak is seen in the 4π mass spectrum at ∼1.66 GeV with a width of ∼0.3 GeV which is identified with theρ′(1600). Maximum likelihood fits show that the peak is dominantly inρ±π∓π0 withB(ρ′→ρ0π0π0)/B(ρ′→ρ±π∓π0)<0.1. This indicates anI=1ρπ final-state interaction. However, no evidence is found for any resonant ρπ state such as anA1 orπ′.

2 data tables
Table 1

AFTER OMEGA EXCLUSION.

Table 2

ERROR IS DOMINANTLY SYSTEMATIC.


VECTOR MESON PRODUCTION IN HYPERCHARGE EXCHANGE REACTIONS AT 7-GeV/c AND 11.5-GeV/c

Ballam, Joseph ; Brau, J. ; Bouchez, J. ; et al.
Nucl.Phys.B 166 (1980) 189-206, 1980.
Inspire Record 143136 DOI 10.17182/hepdata.34582

Results are presented on vector meson production in the hypercharge exchange reactions: π + p → K ∗+ (890) Y + and K − p→ ρ − Y + where Y + is either Σ + or Y ∗+ (1385). These reactions have been studied at 7 GeV/ c and 11.5 GeV/ c using the SLAC Hybrid Facility. Total and differential cross sections, hyperon polarization, and vector meson decay angular distributions are presented. We find that reactions with Σ + production are dominated by natural parity exchange. The Y ∗ (1385) reactions are consistent with substantial natural parity exchange contributions but also show significant unnatural parity exchange. The differential cross sections and polarization measurements for the vector meson production are compared to the pseudoscalar production reactions.

7 data tables
Table 1

Axis error includes +- 20/20 contribution.

Table 2

Axis error includes +- 20/20 contribution.

Table 3

Axis error includes +- 20/20 contribution.

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PRODUCTION AND DECAY ANGULAR DISTRIBUTIONS OF THE Y* (1385) IN THE LINE REVERSED REACTIONS: pi+ p ---> K+ Y* (1385) AND K- p ---> pi- Y* (1385) AT 11.5-GeV/c

Cautis, C.V. ; Ballam, Joseph ; Bouchez, J. ; et al.
Nucl.Phys.B 156 (1979) 507-531, 1979.
Inspire Record 133382 DOI 10.17182/hepdata.34679

We have measured in a single experimental setup, the differential cross sections and decay angular distributions of the Y ∗ (1385) produced in the two line-reversed reactions: π + p → K + Y ∗+ (1385) (279 events/ω b ) and K − p → π − Y ∗+ (1385) (190 events/ωb) at 11.5 GeV/ c . The data have been derived from a triggered bubble-chamber experiment using the SLAC Hybrid Facility. We find the differential cross sections and Y ∗ polarizations for the two reactions to be in agreement with exchange-degeneracy predictions, if kinematic differences are taken into account. The Stodolsky-Sakurai and additive quark model predictions are in agreement with the main features of the decay angular distributions of the Y ∗ (1385), except for small violations at low momentum transfer, which can be associated with a finite helicity non-flip contribution in the forward direction.

6 data tables
Table 1

Axis error includes +- 10/10 contribution.

Table 2

THESE FINAL DIFFERENTIAL CROSS SECTIONS ARE INCLUDED IN THE RECORD OF J. BALLAM ET AL., PRL 41, 676 (1978).

Table 3

TRANSVERSITY AMPLITUDES FOR SIG(1385P13)+ PRODUCTION. THE IMAGINARY PARTS OF T(11) AND T(-1-1) WERE ARBITRARILY FIXED AT ZERO.

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Confirmation of Exchange Degeneracy Predictions in the Line Reversed Reactions: $\pi^+ p \to K^+ Y^*(1385)$ and $K^- p \to \pi^- Y^*(1385)$ at 11.6-{GeV}/$c$

Ballam, Joseph ; Bouchez, J. ; Carroll, J.T. ; et al.
Phys.Rev.Lett. 41 (1978) 676, 1978.
Inspire Record 130550 DOI 10.17182/hepdata.20815

We have measured in a single experimental setup the differential cross sections and polarizations of the Y*(1385) produced in the two line-reversed reactions π+p→K+Y*(1385) (260 eV/μb) and K−p→π−Y*(1385) (180 eV/μb) at 11.5 GeV/c. We compare these results to Σ+ production in the same experiment. The data have been derived from a triggered bubble-chamber experiment using the SLAC Hybrid Facility. We find that both helicity-flip-dominated (Y*) and helicity-nonflip-dominated (Σ) processes are consistent with weak-exchange-degeneracy predictions.

5 data tables
Table 1

Axis error includes +- 10/10 contribution.

Table 2

Axis error includes +- 10/10 contribution.

Table 3

Axis error includes +- 10/10 contribution.

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The Reactions K- p --> pi-+ Sigma+- at 4.2-GeV/c

The Amsterdam-CERN-Nijmegen-Oxford collaboration Massaro, G.G.G. ; Barlag, S. ; de Groot, A.J. ; et al.
Phys.Lett.B 66 (1977) 385-389, 1977.
Inspire Record 110532 DOI 10.17182/hepdata.27595

We present differential cross sections and the Σ + polarization for the reactions K − p → π ∓ Σ ± using data from a high statistics bubble chamber experiment at 4.2 GeV/ c incident momentum. The statistical level allows a detailed analysis of these reactions over the whole t range. Several significant structures are observed. Comparisons are made with SU(3)-related reactions; for backward production of π − Σ + such a comparison shows good evidence for Δ exchange. The exotic forward peak in K − p → π + Σ − is definitely confirmed.

7 data tables
Table 1

Axis error includes +- 5/5 contribution.

Table 2

Axis error includes +- 5/5 contribution.

Table 3

Axis error includes +- 5/5 contribution.

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THE REACTION pi+ n ---> p omega AT 13-GeV/c

Paler, K. ; Tebes, J. ; Badewitz, R.C. ; et al.
Lett.Nuovo Cim. 4 (1972) 745, 1972.
Inspire Record 74599 DOI 10.17182/hepdata.37350

None

3 data tables
Table 1

SIMPLE BREIT-WIGNER FIT WITH ESTIMATED BACKGROUND OF 26 +- 8 PCT.

Table 2

MEASURED OFF GRAPH. BACKGROUND NOT SUBTRACTED. NOT CORRECTED FOR SMALL -T PAULI EXCLUSION EFFECTS (NEGLIGIBLE COMPARED WITH STATISTICAL ERRORS).

Table 3

No description provided.


Anti-p p elastic scattering in the t-meson region

Kalbfleisch, G.R. ; Strand, R.C. ; Vanderburg, V. ;
Nucl.Phys.B 30 (1971) 466-476, 1971.
Inspire Record 68593 DOI 10.17182/hepdata.33324

We have made improved measurements of 43.8 ± 0.8, 41.3 ± 0.4 and 39.3 ± 0.8 mb for the p p elastic cross sections at 1.11, 1.33 and 1.52 GeV/ c laboratory momenta respectively. Sharp forward peaks in the differential cross sections with broad secondary maxima agree with previous observations [3–6]. The forward differential cross sections are (11 ± 3)% above the optical point in agreement with real amplitudes extended from lower momenta using dispersion relations [7]. The elastic cross sections do not show any structure in the s -channel. Backward differential cross sections show the onset of a “third diffraction peak” but no evidence for other structure in agreement with earlier experiments [6, 13].

5 data tables
Table 1

STATISTICAL PLUS SYSTEMATIC ERRORS.

Table 2

STATISTICAL PLUS SYSTEMATIC ERRORS.

Table 3

COUNTS WERE MULTIPLIED BY 1.000 TO GET THESE.. TOTAL NUMBER EVENTS= 543. READ FROM GRAPH.

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