Date

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Photoproduction of J / psi mesons at HERA

The H1 collaboration Ahmed, T. ; Aid, S. ; Andreev, V. ; et al.
Phys.Lett.B 338 (1994) 507-518, 1994.
Inspire Record 376566 DOI 10.17182/hepdata.45103

We present a study of J ψ meson production in collisions of 26.7 GeV electrons with 820 GeV protons, performed with the H1-detector at the HERA collider at DESY. The J ψ mesons are detected via their leptonic decays both to electrons and muons. Requiring exactly two particles in the detector, a cross section of σ(ep → J ψ X) = (8.8±2.0±2.2) nb is determined for 30 GeV ≤ W γp ≤ 180 GeV and Q 2 ≲ 4 GeV 2 . Using the flux of quasi-real photons with Q 2 ≲ 4 GeV 2 , a total production cross section of σ ( γp → J / ψX ) = (56±13±14) nb is derived at an average W γp =90 GeV. The distribution of the squared momentum transfer t from the proton to the J ψ can be fitted using an exponential exp(− b ∥ t ∥) below a ∥ t ∥ of 0.75 GeV 2 yielding a slope parameter of b = (4.7±1.9) GeV −2 .

4 data tables

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QED background subtracted.

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Transverse momentum distributions of eta mesons in near threshold relativistic heavy ion reactions

Berg, F.D. ; Pfeiffer, M. ; Schwalb, O. ; et al.
Phys.Rev.Lett. 72 (1994) 977-980, 1994.
Inspire Record 376197 DOI 10.17182/hepdata.20916

Transverse momentum spectra of η mesons have been measured near the free nucleon-nucleon production threshold in the heavy ion reactions Ar40+ Canat, Kr86 + Zrnat, and Au197+ Au197 at 1.0A GeV and also in Ar40+ Canat at 1.5A GeV. The measured transverse momentum distributions are compared to model calculations. The relative abundance of Δ(1232) and N(1535) resonances excited in the collision is deduced. A comparison to pion data reveals scaling with the transverse mass of the emitted meson.

3 data tables

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Extrapolation to full solid angle.


Azimuthal asymmetry of neutral pion emission in Au + Au reactions at 1-GeV/u

Venema, L.B. ; Braak, H. ; Lohner, H. ; et al.
KVI-983, 1993.
Inspire Record 359163 DOI 10.17182/hepdata.30556

None

4 data tables

THE AZIMUTHAL ANGLE DISTRIBUTIONS OF PI0 HAVE BEEN FITTED BY: D(N)/D(PHI)=N*(1+CONST(Q=1)*COS(PHI)+CONST(Q=2)*COS(2*PHI)), WHERE PHI IS THE AZIMUTHAL ANGLEOF PI0 RELATIVE TO THE FOLLOWING COORDINATE SYSTEM: Z AXIS DIRECTED ALONG BEAM MOMENTUM, X AXIS DIRECTED ALONG TRANSVERSE MOMENTUM CONSTRUCTED FROM TRANSVERSE MOMENTA OF THE FINAL STATE PARTICLES (SEE PAPER). THE 17 PCT OF ALL NONPERIPHERAL EVENTS HAS BEEN REMOVED (SEE PAPER).

THE AZIMUTHAL ANGLE DISTRIBUTIONS OF CHARGED PARTICLES HAVE BEEN FITTED BY : D(N)/D(PHI)=N *(1+CONST(Q=1)*COS(PHI)+CONST(Q=2)*COS(2*PHI)), WHERE PHI IS THEAZIMUTHAL ANGLE OF CHARGED PARTICLE RELATIVE TO THE FOLLOWING COORDINATE SYSTEM : Z AXIS DIRECTED ALONG BEAM MOMENTUM, X AXIS DIRECTED ALONG TRANSVERSE MOMENTU M CONSTRUCTED FROM TRANSVERSE MOMENTA OF THE FINAL STATE PARTICLES (SEE PAPER). A systematic error of 0.03 has been estimated for CONST(Q=1) and CONST(Q= 2).

THE AZIMUTHAL ANGLE DISTRIBUTIONS OF NEUTRONS HAVE BEEN FITTED BY: D(N)/D (PHI)=N *(1+CONST(Q=1)*COS(PHI)+CONST(Q=2)*COS(2*PHI)), WHERE PHI IS THE AZIMUTHAL ANGLE OF NEUTRON RELATIVE TO THE FOLLOWING COORDINATE SYSTEM: Z AXIS DIRECTEDALONG BEAM MOMENTUM, X AXIS DIRECTED ALONG TRANSVERSE MOMENTUM CONSTRUCTED FRO M TRANSVERSE MOMENTA OF THE FINAL STATE PARTICLES (SEE PAPER). A systematic error of 0.03 has been estimated for CONST(Q=1) and CONST(Q= 2).

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STUDY OF ELASTIC anti-p p SCATTERING AT 32-GeV/c

Bogolyubsky, M.Yu. ; Kiryunin, A.E. ; Kotova, A.I. ; et al.
Sov.J.Nucl.Phys. 41 (1985) 773, 1985.
Inspire Record 205769 DOI 10.17182/hepdata.40982

None

3 data tables

Axis error includes +- 0.0/0.0 contribution (?////FOR LOSSES OF PROTONS WITH MOMENTUM >1.2 GEV).

Axis error includes +- 0.0/0.0 contribution (?////FOR LOSSES OF PROTONS WITH MOMENTUM >1.2 GEV).

Axis error includes +- 0.0/0.0 contribution (?////FOR LOSSES OF PROTONS WITH MOMENTUM >1.2 GEV).


Pion-Proton Backward Elastic Scattering Between 30 and 90 GeV/c

Baker, W.F. ; Eartly, David P. ; Kalbach, R.M. ; et al.
Phys.Rev.D 27 (1983) 1999, 1983.
Inspire Record 181377 DOI 10.17182/hepdata.23836

Backward elastic scattering of π± on protons has been measured for incident pion momenta between 30 and 90 GeV/c and 0≤−u≤0.5 (GeV/c)2. The u dependence of the cross sections is similar to that observed at lower momenta, and Regge models give acceptable fits to the data.

9 data tables

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Measurement of $\pi^{\pm}$p Backward Elastic Scattering Between 30 and 90 GeV/c

Baker, W.F. ; Eartly, David P. ; Kalbach, R.M. ; et al.
Phys.Rev.Lett. 43 (1979) 1635, 1979.
Inspire Record 141766 DOI 10.17182/hepdata.20758

Measurements of π±p backward elastic scattering have been made for incident pion momenta between 30 and 90 GeV/c and for 0<−u<0.5 (GeV/c)2. The momentum dependence of the cross sections is of a form expected from a simple Regge model, and the u dependence of the cross sections is similar to that observed at lower momenta.

9 data tables

No description provided.

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Inelastic Diffractive Scattering at FNAL Energies

Ayres, D.S. ; Diebold, Robert E. ; Cutts, D. ; et al.
Phys.Rev.Lett. 37 (1976) 1724, 1976.
Inspire Record 109174 DOI 10.17182/hepdata.21057

Inelastic differential cross sections have been measured for π±p, K±p, and p±p at 140- and 175-GeV/c incident momentum over a |t| range from 0.05 to 0.6 GeV2 and covering a missing-mass region from 2.4 to 9 GeV2. For Mx2 greater than 4 GeV2, the invariant quantity Mx2d2σdtdMx2 was found to be independent of Mx2 at fixed t and could be adequately described by a simple triple-Pomeron form. The values obtained for the triple-Pomeron couplings are identical within statistics for all channels.

1 data table

Data from 140 GeV and 175 GeV are combined. The distributions are fit to CONST*(SLOPE(C=1)*T+SLOPE(C=2)*T**2).


A Comparison of the Shapes of pi+ p and p p Diffraction Peaks from 50-GeV/c to 175-GeV/c

The Fermilab Single Arm Spectrometer Group collaboration Ayres, D.S. ; Diebold, Robert E. ; Maclay, G.J. ; et al.
Phys.Rev.Lett. 37 (1976) 548, 1976.
Inspire Record 108238 DOI 10.17182/hepdata.21073

The ratio of π+p to pp elastic scattering is found to be smoothly varying over the range −t=0.03 to 0.4 GeV2. It is well fitted by a single exponential, indicating the forward behavior must be quite similar for the two reactions.

1 data table

ACTUALLY THE DATA ARE THE EXPONENTIAL SLOPE OF THE RATIO OF D(SIG)/DT FOR THE TWO REACTIONS.


Measurement of Elastic Scattering of Hadrons on Protons from 50-GeV/c to 175-GeV/c

The Fermilab Single Arm Spectrometer Group collaboration Awes, D.S. ; Diebold, R. ; Maclay, G.J. ; et al.
Phys.Rev.Lett. 35 (1975) 1195, 1975.
Inspire Record 98699 DOI 10.17182/hepdata.21217

Differential cross sections have been measured at Fermilab with a focusing spectrometer for π±p, K±p, and p±p elastic scattering at 50-, 70-, 100-, 140-, and 175-GeV/c incident momentum over the |t| range 0.03 to 0.8 GeV2. The results are smooth in t and are parametrized by quadratic exponential fits.

1 data table

DATA PRESENTED AGAIN IN LATER PAPER.