Date

Measurement of the pi0 pi0 cross-section in anti-p p annihilations at s**(1/2) = 3-GeV

The R704 collaboration Baglin, C. ; Baird, S. ; Bassompierre, G. ; et al.
Nucl.Phys.B 368 (1992) 175-189, 1992.
Inspire Record 334973 DOI 10.17182/hepdata.33012

Data collected in the experiment R704 at the CERN ISR are used to study the annihilation process p p → π 0 π 0 at several centre-of-mass energies between 2.97 and 3.56 GeV. A total sample of 7359 events has been identified, from which cross sections and angular distributions in the interval 0 < | cos θ ∗ | < 0.5 have been measured.

2 data tables

No description provided.

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Differential cross-sections and analyzing powers for anti-p p ---> pi- pi+ and K- K+ from 360-MeV/c to 1550-MeV/c

Hasan, A. ; Bugg, D.V. ; Hall, J.R. ; et al.
Nucl.Phys.B 378 (1992) 3-51, 1992.
Inspire Record 339576 DOI 10.17182/hepdata.6880

Analysing powers and differential cross sections for p p → π − π + and p p → K − K + have been measured over the full angular range using a polarised target at LEAR at 20 beam momenta from 360 to 1550 MeV/ c . Discrepancies in the normalisation of earlier d σ/ d Ω data at low momenta are clarified. Above 1000 MeV/ c , A 0N results confirm values close to +1 over most of the angular range for both reactions, in excellent agreement with earlier data of lower statistics. Below 1000 MeV/ c , where the analysing power is measured for the first time, large variations of A 0N with energy and angle are present.

84 data tables

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Backward emitted protons in interactions of neutrinos with nuclei in photoemulsion. FNAL-564 experiment

Dayon, M. ; Rappoport, V. ; Smirnitsky, V. ; et al.
Z.Phys.C 56 (1992) 391-393, 1992.
Inspire Record 345621 DOI 10.17182/hepdata.14532

Backward emitted protons with momentump>0.3 GeV/c in interactions of neutrino in the energy range 10–200 GeV with photoemulsion nuclei were investigated. Energy spectrum slope parameter of backward protons was measured to beT0=48.9±7.9 MeV. TheA-dependence power index of relative mean yield of backward protons was found to bea=0.68±0.12. A drop in the mean yield of backward protons at the four momentum squared over ∼15 (GeV/c)2 (the neutrino energy over ∼50 GeV) was observed.

3 data tables

NUCLEUS IS AVERAGE NUCLEI OF NUCLEAR EMULSION, <A> ABOUT 80.

NUCLEUS IS AVERAGE NUCLEI OF NUCLEAR EMULSION, <A> ABOUT 80.

NUCLEUS IS AVERAGE NUCLEI OF NUCLEAR EMULSION, <A> ABOUT 80.


An Experimental study of the process gamma gamma ---> pi+ pi-

The CELLO collaboration Behrend, H.J. ; Criegee, L. ; Field, J.H. ; et al.
Z.Phys.C 56 (1992) 381-390, 1992.
Inspire Record 345437 DOI 10.17182/hepdata.14534

Using the CELLO detector, we have measured cross sections for the processγγ→π+π− in the mass range 0.75–1.9 GeV/c2. A partial wave fit to the data indicates the presence of a sizeableS-wave amplitude with signs of resonant behaviour. Values for the γγ width of thef2(1270) are given, showing the model-dependence of this quantity. At higher dipion masses, the model of Brodsky and Lepage is found to give an order of magnitude description of the data.

2 data tables

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Meson production in p + U, O + U and S + U interactions at 200-GeV/nucleon.

The NA38 collaboration Abreu, M.C. ; Baglin, C. ; Baldisseri, A. ; et al.
Z.Phys.C 55 (1992) 365-371, 1992.
Inspire Record 344266 DOI 10.17182/hepdata.14583

Meson production in proton, oxygen and sulphur interactions with uranium targets at 200 GeV/nucleon is studied. We measure the inclusive meson cross-section d σ/dPT2 and its evolution fromp+U to S+U. The cross-section fitted with an exponential gives an inverse slopePT0 of the order of 210 MeV/c. As a function of the neutral transverse energy,PT0 values show a slight rise followed by a plateau. The normalized difference (σ+−σ−)/σ− between positive and negative meson cross-sections is found to increase withET.

6 data tables

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Collective excitation of Delta isobar in the charge exchange reactions (Li-7, Be-7) and (H-3, He-3) at a momentum of 3-GeV/c/nucleon

Avramenko, S.A. ; Abdurakhimov, A.U. ; Aksinenko, V.D. ; et al.
JETP Lett. 55 (1992) 707-712, 1992.
Inspire Record 346156 DOI 10.17182/hepdata.16833

None

2 data tables

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Narrow baryonia with open and hidden strangeness.

The EXCHARM collaboration Aleev, A.N. ; Balandin, V.P. ; Chvyrov, A.S. ; et al.
Phys.Atom.Nucl. 56 (1993) 1358-1366, 1993.
Inspire Record 344917 DOI 10.17182/hepdata.17233

None

4 data tables

NUCLEUS IS P, C, AL, CU.

NUCLEUS IS P, C, AL, CU.

NUCLEUS IS P, C, AL, CU.

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Limit on the anti-d / anti-u asymmetry of the nucleon sea from Drell-Yan production

McGaughey, P.L. ; Moss, J.M. ; Alde, D.M. ; et al.
Phys.Rev.Lett. 69 (1992) 1726-1728, 1992.
Inspire Record 344919 DOI 10.17182/hepdata.19848

We present an analysis of 800-GeV proton-induced Drell-Yan production data from isoscalar targets 2H and C, and from W, which has a large neutron excess. The ratio of cross sections per nucleon, R-σW/σIS, is sensitive to the difference between the d¯(x) and u¯(x) structure functions of the proton. We find that R is close to unity in the range 0.04≤x≤0.27, allowing upper limits to be set on the d¯-u¯ asymmetry. Additionally, the shape of the differential cross section m3 d2σ/dxF dm for 2H at xF≊0 shows no evidence of an asymmetric sea in the proton. We examine the implications of these data for various models of the violation of the Gottfried sum rule in deep-inelastic lepton scattering.

1 data table

Upper limit at the 2sigma statistical error level. Mass of MU+ MU- in GeV.


Polarization of Lambda hyperons produced by the quasifree (pi+, K+) reaction on C-12

Ajimura, S. ; Ejiri, H. ; Higashi, A. ; et al.
Phys.Rev.Lett. 68 (1992) 2137-2140, 1992.
Inspire Record 338084 DOI 10.17182/hepdata.19866

The polarization of quasifree Λ hyperons produced by the (π+K+) reaction on C12 and on the deuteron was measured for the first time. The asymmetry of pions from weak decay of the Λ hyperon was used to determine the polarization. The polarization for the deuterium target was found to be consistent with that for the elementary n(π+,K+)Λ reaction. The polarization of the Λ produced by the quasifree process from C12 is consistent with that for the elementary reaction, which demonstrates that the spin characteristics of the elementary reaction are not modified by the nuclear medium.

1 data table

No description provided.


Proton polarization from pi+ absorption in He-3

MayTal-Beck, S. ; Aclander, Jaime L.S. ; Altman, A. ; et al.
Phys.Rev.Lett. 68 (1992) 3012-3015, 1992.
Inspire Record 339565 DOI 10.17182/hepdata.19868

We present the first polarization measurements for pion absorption on a nucleus heavier than the deuteron. The polarization of protons resulting from π+ absorption in the He3 was measured at bombarding energies of 120 and 250 MeV. Protons from absorption in a quasideuteron were selected by applying kinematical constraints. A significant discrepancy was observed between the experimental results and theoretical predictions. At 120 MeV the measured polarizations for He3 are consistent with those of the deuteron. At 250 MeV the angular distribution of the polarization is significantly different than for the deuteron, showing sensitivity to the nuclear density, and thus may be sensitive to short range correlations between nucleons.

4 data tables

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