Di-jet production in gamma-gamma collisions at LEP2

The DELPHI collaboration Abdallah, J. ; Abreu, P. ; Adam, W. ; et al.
Eur.Phys.J.C 58 (2008) 531-541, 2008.
Inspire Record 806241 DOI 10.17182/hepdata.51688

The production of two high-p_T jets in the interactions of quasi-real photons in e+e- collisions at sqrt{s_ee} from 189 GeV to 209 GeV is studied with data corresponding to an integrated e+e- luminosity of 550 pb^{-1}. The jets reconstructed by the k_T cluster algorithm are defined within the pseudo-rapidity range -1 < eta < 1 and with jet transverse momentum, p_T, above 3 GeV/c. The differential di-jet cross-section is measured as a function of the mean transverse momentum ptmean of the jets and is compared to perturbative QCD calculations.

0 data tables match query

Target associated particle production in ultrarelativistic nucleus-nucleus collisions

Sengupta, K. ; Jain, P.L. ; Singh, G. ;
Mod.Phys.Lett.A 6 (1991) 29-39, 1991.
Inspire Record 316958 DOI 10.17182/hepdata.37873

We report the multiplicity and angular distributions of the low energy target-associated particles from 32S and 16O induced reactions at 200 GeV/nucleon and 16O induced reactions at 60 GeV/nucleon in emulsion. The results are compared with the Monte-Carlo Code VENUS.

0 data tables match query

Excitation of the Delta (1232) resonance in proton - nucleus collisions

Trzaska, M. ; Pelte, D. ; Lemaire, M. -C. ; et al.
Z.Phys.A 340 (1991) 325-331, 1991.
Inspire Record 314551 DOI 10.17182/hepdata.15689

The excitation of theΔ resonance is observed in proton collisions on C, Nb and Pb targets at 0.8 and 1.6 GeV incident energies. The mass E0 and widthΓ of the resonance are determined from the invariant mass spectra of correlated (p, π±)-pairs in the final state of the collision: The mass E0 is smaller than that of the free resonance, however by comparing to intra-nuclear cascade calculations, this reduction is traced back to the effects of Fermi motion, NN scattering and pion reabsorption in nuclear matter.

0 data tables match query

Particle production in He Li collisions at 4.5-A/GeV/c

Al-Baaj, E. ; Al-Baaj, S. ; Besliu, C. ; et al.
Nuovo Cim.A 107 (1994) 1611-1623, 1994.
Inspire Record 384746 DOI 10.17182/hepdata.37842

In this paper the main experimental results on some significant physical quantities obtained in He−Li collisions at 4.5A GeV/c are presented. The experiments have been performed at the Syncrophasotron from JINR Dubna, in the frame of the SKM 200 Collaboration.

0 data tables match query

CHARGED AND NEUTRAL PARTICLE PRODUCTION FROM 400-GEV/C P P COLLISIONS

Kass, R.D. ; Ko, W. ; Lander, R.L. ; et al.
Phys.Rev.D 20 (1979) 605-614, 1979.
Inspire Record 146628 DOI 10.17182/hepdata.24207

Charged- and neutral-particle production from 400-GeV/c pp collisions are measured simultaneously using the Fermilab 15-ft bubble chamber. The π0 and K0 cross sections are rising at Fermilab energies, while the Λ0 cross section remains fairly constant. Similarly, the average number of π0's and K0's increases as a function of the number of negative particles in an event, yet no such dependence is noted for the Λ0's. The ratio of average number of π0 to average number of π− per inelastic collisions is found to be constant at Serpukhov and Fermilab energies (40 to 400 GeV/c) and equal to 1.22±0.02. Cross sections for Σ0 and Σ¯0 production are measured and limits are found for η0 and ω0 production. Neutral- and charged-pion correlations are compared with five pion-production models.

0 data tables match query

Energy dependence of pion and kaon production in central Pb + Pb collisions.

The NA49 collaboration Afanasiev, S.V. ; Anticic, T. ; Barna, D. ; et al.
Phys.Rev.C 66 (2002) 054902, 2002.
Inspire Record 586383 DOI 10.17182/hepdata.31729

Measurements of charged pion and kaon production in central Pb+Pb collisions at 40, 80 and 158 AGeV are presented. These are compared with data at lower and higher energies as well as with results from p+p interactions. The mean pion multiplicity per wounded nucleon increases approximately linearly with s_NN^1/4 with a change of slope starting in the region 15-40 AGeV. The change from pion suppression with respect to p+p interactions, as observed at low collision energies, to pion enhancement at high energies occurs at about 40 AGeV. A non-monotonic energy dependence of the ratio of K^+ to pi^+ yields is observed, with a maximum close to 40 AGeV and an indication of a nearly constant value at higher energies.The measured dependences may be related to an increase of the entropy production and a decrease of the strangeness to entropy ratio in central Pb+Pb collisions in the low SPS energy range, which is consistent with the hypothesis that a transient state of deconfined matter is created above these energies. Other interpretations of the data are also discussed.

0 data tables match query

Multistep production of eta and hard pi0 mesons in subthreshold Au Au collisions.

Wolf, A.R. ; Appenheimer, M. ; Averbeck, R. ; et al.
Phys.Rev.Lett. 80 (1998) 5281-5284, 1998.
Inspire Record 471975 DOI 10.17182/hepdata.41989

The neutral π0 and η mesons are studied in 197Au−197Au collisions at an incident energy of 800AMeV, substantially below the threshold for η production in N−N collisions. While the gross π0 multiplicity increases almost linearly with the number of participant nucleons, the multiplicities of η and hard π0 mesons show a stronger than linear dependence. The nonlinearity is governed by the average transverse-mass excess 〈mt〉−(s−2mN) of the mesons and is insensitive to their final-state interaction in the nuclear medium.

0 data tables match query

Mass dependence of pi0 production in heavy ion collisions at 1-A/GeV

Schwalb, O. ; Pfeiffer, M. ; Berg, F.-D. ; et al.
Phys.Lett.B 321 (1994) 20-25, 1994.
Inspire Record 376130 DOI 10.17182/hepdata.28781

The production of neutral pions has been studied in the reactions 40 Ar + nat Ca , 86 Kr + nat Zr and 197 Au + 197 Au at 1 A GeV. For high energy pions emitted from the heavier systems a steeper than linear rise of the pion multiplicity with the centrality of the reaction is observed, indicating a pion production process other than binary nucleon-nucleon collisions. At low transverse momenta an enhancement of the π 0 -multiplicity increasing with the mass of the collision system is found. Systematic discrepancies between the experimental results and recent BUU, QMD and Cascade calculations are discussed.

0 data tables match query

Correlations Between Neutral and Charged Pions Produced in 300-{GeV}/$c p p$ Collisions

Kafka, T. ; LoPinto, F. ; Brody, A. ; et al.
Phys.Rev.D 19 (1979) 76, 1979.
Inspire Record 6901 DOI 10.17182/hepdata.24255

Neutral-pion production in pp interactions has been studied using 8000 photon conversions in the Fermilab 15-ft bubble chamber. Inclusive π0 multiplicity moments and ππ correlation integrals are presented; f200 is determined to be + 3.0±0.8. For the semi-inclusive π0 multiplicity distributions we find 〈n(π0)〉n− to increase with n−, while the dispersions are n− independent. Results on f2−0, f200, and f2,n−00 are compared to predictions of simple cluster models.

0 data tables match query

Jets of nuclear matter in He-A(T) inelastic collisions at 4.5-A-GeV/c.

Besliu, C. ; Jipa, A. ; Zaharia, R. ; et al.
Eur.Phys.J.A 1 (1998) 65-75, 1998.
Inspire Record 467239 DOI 10.17182/hepdata.43769

The problem of the nuclear matter jets in nucleus-nucleus collisions at 4.5 A GeV/c is discussed. The global analysis of experimental data, namely the sphericity tensor, is used to evidence such jets.

0 data tables match query