Atkinson, M.
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Measurement of the target asymmetry of eta and pi0 photoproduction on the proton.

Bock, A. ; Anton, G. ; Beulertz, W. ; et al.
Phys.Rev.Lett. 81 (1998) 534-537, 1998.
Inspire Record 474492 DOI 10.17182/hepdata.19492

At the tagged photon facility PHOENICS at the Bonn accelerator ELSA a measurement of the target asymmetry of the reaction γp→pη from threshold to 1150 MeV has been performed. Simultaneously the reaction γp→pπ0 has been measured in the first resonance region. Results are presented for both reactions. The target asymmetry data are suited to put considerable constraints on the model parameters used for the theoretical description of meson photoproduction.

3 data tables
Table 1

The errors include statistical and systematic errors added in quadrature. The target asymmetry determines as the rates belonging to different polarization states: (N_pol-up-N_pol_down)/(N_pol-up+N_pol_down).

Table 2

The errors include statistical and systematic errors added in quadrature. The target asymmetry determines as the rates belonging to different polarization states: (N_pol-up-N_pol_down)/(N_pol-up+N_pol_down).

Table 3

The errors include statistical and systematic errors added in quadrature. The target asymmetry determines as the rates belonging to different polarization states: (N_pol-up-N_pol_down)/(N_pol-up+N_pol_down).


Production of Phi and omega mesons in near-threshold p p reactions.

The DISTO collaboration Balestra, F. ; Bedfer, Y. ; Bertini, R. ; et al.
Phys.Rev.Lett. 81 (1998) 4572-4575, 1998.
Inspire Record 481641 DOI 10.17182/hepdata.19496

The ratio of the exclusive production cross sections for φ and ω mesons has been measured in pp reactions at Tbeam=2.85GeV. The observed φ/ω ratio is (3.7±0.7−0.9+1.2)×10−3. After phase space corrections, this ratio is about a factor of 10 enhanced relative to naive predictions based upon the Okubo-Zweig-Iizuka rule, in comparison to an enhancement by a factor of ∼3 previously observed at higher energies. The modest increase of this enhancement near the production threshold is compared to the much larger increase of the φ/ω ratio observed in specific channels of p¯p annihilation experiments.

1 data table
Table 1

No description provided.


Differential cross section of the p n --> p p(1)S(0)) pi- reaction extracted from p d --> p p p pi-.

Duncan, F. ; Hahn, H. ; Aclander, C. ; et al.
Phys.Rev.Lett. 80 (1998) 4390-4393, 1998.
Inspire Record 471244 DOI 10.17182/hepdata.19508

The double differential cross section for pn→pp(1S0)π− at three beam energies has been extracted from the quasifree process pd→pppπ−. A comparison is carried out with single differential cross section measurements for 3He(π−,pn)n, where the pion is thought to be absorbed onto a pp(1S0) “diproton” state. A significant difference is observed in the shape of the angular distribution between the production and absorption data. This difference is ascribed to the effects of the 3He nuclear environment characterizing the absorption process; however, an adequate theoretical explanation is not available.

3 data tables
Table 1

Only statistical errors are given in the table. Final P P system is in 1S0 ((2S+1) L J) state.

Table 2

Only statistical errors are given in the table. Final P P system is in 1S0 ((2S+1) L J) state.

Table 3

Only statistical errors are given in the table. Final P P system is in 1S0 ((2S+1) L J) state.


Search for psi(2S) production in e+ e- annihilations at 4.03-GeV

The BES collaboration Bai, J.Z. ; Bian, J.G. ; Blum, I. ; et al.
Phys.Rev.D 57 (1998) 3854-3859, 1998.
Inspire Record 468969 DOI 10.17182/hepdata.22270

A search is performed for the production of the ψ(2S) in e+e− annihilation at a center-of-mass energy of 4.03 GeV using the BES detector operated at the Beijing Electron Positron Collider (BEPC). The kinematic features of the reconstructed ψ(2S) signal are consistent with its being produced only in association with an energetic photon resulting from initial state radiation (ISR). Limits are placed on ψ(2S) production from the decay of unknown charmonia or metastable hybrids that might be produced in e+e− annihilations at 4.03 GeV. Under the assumption that the observed cross section for ψ(2S) production is due entirely to ISR, the partial width Γee of the ψ(2S) is measured to be 2.07±0.32keV.

1 data table
Table 1

PSI(UNSPEC) is considered as a new 3D2 charmonium state. CHI/C(UNSPEC) is considered as any unknown charmonium state. EXOTIC is considered as a metastable hybrid.


Phi emission in central Pb + Pb collisions at 158-GeV/u.

The NA49 collaboration Pühlhofer, Falk ; Appelshäuser, H. ; Bächler, J. ; et al.
Nucl.Phys.A 638 (1998) 431-434, 1998.
Inspire Record 481889 DOI 10.17182/hepdata.36218

Data on φ -production obtained by the CERN NA49 experiment for central Pb+Pb collisions at 158 GeV/u are presented. Compared with pp interactions the φ -yield shows substantial strangeness enhancement: the φ /π ratio is found to increase by a factor of 2.6 ± 0.6, which is approximately the square of the K/π enhancement.

2 data tables
Table 1

5% most central collosions, MT - M0 = 0 - 1.4 GeV, preliminary data.

Table 2

5% most central events.


Tensor analyzing power Ayy of d-p radiative capture

Anklin, H. ; de Bever, L.J. ; Buttazzoni, S. ; et al.
Nucl.Phys.A 636 (1998) 189-206, 1998.
Inspire Record 487232 DOI 10.17182/hepdata.36233

Proton-deuteron radiative capture has been studied with polarized deuterons at a laboratory deuteron energy E d = 45 MeV. Precise data for the tensor analyzing power A yy have been measured in the angular range 50° to 160°. Three-nucleon Faddeev wave functions in the initial scattering and final bound state are calculated using realistic nucleon-nucleon potentials. Mesonic exchange currents are included according to Siegert's theorem. Comparison to other recent experimental data is performed as well.

1 data table
Table 1

No description provided.


Kaon and proton ratios from central Pb + Pb collisions at the CERN SPS.

The NA44 collaboration Kaneta, M. ; Bearden, I.G. ; Bøggild, H. ; et al.
Nucl.Phys.A 638 (1998) 419-422, 1998.
Inspire Record 481886 DOI 10.17182/hepdata.36250

K − /K + and p ¯ / p ratios measured in 158 A·GeV Pb+Pb collisions are shown as a function of transverse momentum P T and centrality in top 8.5% central region. Little centrality dependence of the K − / K + and p ¯ / p ratios is observed. The transverse mass m T distribution and dN/dy of K + , K − , p and p ¯ around mid-rapidity are obtained. The temperature T ch and the chemical potentials for both light and strange quarks (μ q , μ s ) at chemical freeze-out are determined by applying simple thermodynamical model to the present data. The resultant μ q , μ s and T ch are compared with those obtained from similar analysis of SPS S+A and AGS Si+A data. The chemical freeze-out temperature T ch at CERN energies is higher than thermal freeze-out temperature T fo which is extracted from m T distribution of charged hadrons. At AGS energies T ch is close to T fo .

2 data tables
Table 1

Data obtained from the fit of MT spectra.

Table 2

Data obtained from the fit of MT spectra.


Subthreshold antiproton production in p A, d A and alpha A reactions.

Sugaya, Y. ; Ashery, D. ; Chiba, J. ; et al.
Nucl.Phys.A 634 (1998) 115-140, 1998.
Inspire Record 466882 DOI 10.17182/hepdata.36236

An enormous enhancement of antiproton production in deuteron- and α-induced reactions has been observed in the subthreshold energy region between 2 and 5 GeV/nucleon. Antiprotons produced at 5.1° with a momentum range of between 1.0 and 2.5 GeV/ c were measured by a beam-line spectrometer and identified by the time-of-flight method. The production cross sections in the deuteron- and α-induced reactions at an incident energy of 3.5 GeV/nucleon were 2 and 3 orders of magnitude larger than those in proton-induced reaction at the same energy. The enhancement in light-ion reactions could not be explained by the internal motion in the projectile and target nuclei. The target-mass dependence (C, Al, Cu and Pb) of the cross sections has also been studied. Further, the cross sections of π and K productions were measured.

74 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Thermal multifragmentation in p + Au interactions at 2.16-GeV, 3.6-GeV and 8.1-GeV incident energies.

Avdeev, S.P. ; Karnaukhov, V.A. ; Kuznetsov, V.D. ; et al.
Eur.Phys.J.A 3 (1998) 75-83, 1998.
Inspire Record 479490 DOI 10.17182/hepdata.43488

Multiple emission of intermediate-mass fragments has been studied for the collisions p + Au at 2.16, 3.6 and 8.1 GeV with the FASA setup. The mean IMF multiplicities for events with at least one IMF a

1 data table
Table 1

No description provided.


Study of the pi0 pi0 system with the GAMS-4000 spectrometer at 100-GeV/c.

The GAMS collaboration Alde, D. ; Binon, F.G. ; Boutemeur, M. ; et al.
Eur.Phys.J.A 3 (1998) 361-371, 1998.
Inspire Record 474862 DOI 10.17182/hepdata.43500

The πpi-system produced in the charge exchange π−p-reaction at 100 GeV/c has been studied. The experiment was performed at the CERN SPS accelerator with the multiphoton hodoscope spectrometer GAMS-400

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.