HEPData Search

The total cross section of the processe+e− →hadrons has been measured in the center-of-mass energy range between 7.25 and 10.34 GeV using the MD-1 detector at the VEPP-4 collider. The ratioR=σ(e+e− →hadrons)/σ(e+e− →μ+μ−) was found to be constant in this energy range with the average value of 3.58±0.02±0.14.

2 data tables match query

Table 1

Statistical errors only.

Table 2

Mean value of R in the range 7.25 to 10.34 GeV.

Total cross-section of two photon production of hadrons

Baru, S.E. ; Beilin, M.V. ; Blinov, A.E. ; et al.

Z.Phys.C 53 (1992) 219-224, 1992.

Inspire Record 33675 DOI 10.17182/hepdata.14767

The total cross section for γγ→hadrons was measured as a function of the invariant massW of the system (1.25 to 4.25 GeV) at thee+e−-collider VEPP-4 with the detector MD-1. For the first time the data were obtained by detecting both scattered leptons with almost zero emission angles. The mean squared four momentum transfer 〈q2〉 is −0.005 GeV2, the rmsW resolution is 100–250 MeV. The data on the mean charged multiplicity 〈nC〉 are well described by the function 〈nC〉=(1.62 ±0.37)+(1.83±0.45)·ln(W(GeV)). TheW dependence of the total cross section is consistent with the theoretical prediction σ(nb)=240+270/W(GeV).

2 data tables match query

Table 1

No description provided.

Table 2

No description provided.

Pion pair production in photon-photon collisions

Blinov, A.E. ; Blinov, V.E. ; Bondar, A.E. ; et al.

Z.Phys.C 53 (1992) 33-39, 1992.

Inspire Record 335707 DOI 10.17182/hepdata.14772

The process γγ→π+π− was measured using the detector MD-1 at VEPP-4. The two-photon reactionse+e−, μ+ μ− and π+ π− pair production were separated using scintillation counters, Cherenkov counters and shower-range chambers. A radiation widthГγγ(f2(1270))=3.1±0.35±0.35 keV was obtained.

1 data table match query

Table 1

Data read from graph.

Energy dependence of the near-threshold total cross-section for the p p --> p p eta' reaction.

Moskal, P. ; Adam, H.H. ; Balewski, J.T. ; et al.

Phys.Lett.B 474 (2000) 416-422, 2000.

Inspire Record 522744 DOI 10.17182/hepdata.28036

Total cross sections for the pp --> pp eta' reaction have been measured in the excess energy range from Q = 1.53 MeV to Q = 23.64 MeV. The experiment has been performed at the internal installation COSY-11 using a stochastically cooled proton beam of the COoler SYnchrotron COSY and a hydrogen cluster target. The determined energy dependence of the total cross section weakens the hypothesis of the S-wave repulsive interaction between the eta' meson and the proton. New data agree well with predictions based on the phase-space distribution modified by the proton-proton final-state-interaction (FSI) only.

1 data table match query

Table 1

Total cross sections w.r.t the excess energy in the CM system. Statistical errors only are given. As well as the 15 PCT overall systematic uncertainty there is an uncertainty on the energy of 0.44 MeV.

Classical tests for statistical evaporation at 680 MeV Ar-40 + natural Ag

Gelderloos, C.J. ; Alexander, John M. ; Boger, J. ; et al.

Phys.Rev.C 54 (1996) 3056-3061, 1996.

Inspire Record 433950 DOI 10.17182/hepdata.25739

Measurements of the partial linear momentum transfer and production cross sections for light charged particles are reported for the reaction 680 MeV Ar40+natAg. From examination of light charged particle invariant cross section maps and comparison of experimental angular distributions and energy spectra to a reaction kinematics simulation, an average value of 85% linear momentum transfer is deduced, with a spin range of (0–75)ħ. Integration over energy and angle yields single and coincident light charged particle production cross sections. © 1996 The American Physical Society.

1 data table match query

Table 1

No description provided.

Study of eta pi- production by pions in Coulomb field.

The VES collaboration Amelin, D.V. ; Berdnikov, E.B. ; Bityukov, S.I. ; et al.

363-366, 1998.

Inspire Record 477863 DOI 10.17182/hepdata.41663

The production of eta pi - system at low mass by the pi- beam in the Coulomb field of Be nuclei was studied. The cross section of the reaction pi- Be --> eta pi- Be was compared to the experimental data on the decay eta --> pi+ pi- gamma and to the theoretical predictions.

1 data table match query

Table 1

rivet Analysis
Charged particle multiplicity distributions in Z0 hadronic decays

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adami, F. ; et al.

Z.Phys.C 50 (1991) 185-194, 1991.

Inspire Record 301657 DOI 10.17182/hepdata.15028

This paper presents an analysis of the multiplicity distributions of charged particles produced inZ0 hadronic decays in the DELPHI detector. It is based on a sample of 25364 events. The average multiplicity is <nch>=20.71±0.04(stat)±0.77(syst) and the dispersionD=6.28±0.03(stat)±0.43(syst). The data are compared with the results at lower energies and with the predictions of phenomenological models. The Lund parton shower model describes the data reasonably well. The multiplicity distributions show approximate KNO-scaling. They also show positive forward-backward correlations that are strongest in the central region of rapidity and for particles of opposite charge.

5 data tables match query

Table 1

Charged particle multiplicity distribution for the raw data in full phase space.

Table 2

Charged particle multiplicity distribution for full phase space. Errors include systematics. A 2 pct correction for excess electrons from photon conversions is not included. The first two points, at N=2 and 4, were not measured but taken from the Lund PS model.

Table 3

Charged particle multiplicity distribution for single hemisphere. Errors include systematics. A 2 pct correction for excess electrons from photon conversions is not included.

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First Measurements of Hadronic Decays of the $Z$ Boson

The MARK-II collaboration Abrams, G.S. ; Adolphsen, Chris ; Aleksan, R. ; et al.

Phys.Rev.Lett. 63 (1989) 1558, 1989.

Inspire Record 282670 DOI 10.17182/hepdata.20044

We have observed hadronic final states produced in the decays of Z bosons. In order to study the parton structure of these events, we compare the distributions in sphericity, thurst, aplanarity, and number of jets to the predictions of several QCD-based models and to data from lower energies. The data and models agree within the present statistical precision.

5 data tables match query

Table 1

Corrected event shape distributions.

Table 2

Corrected event shape distributions.

Table 3

Corrected event shape distributions.