Strangeness in nuclear collisions

Gazdzicki, Marek ; Rohrich, Dieter ;
Z.Phys. C71 (1996) 55-64, 1996.
Inspire Record 420462 DOI 10.17182/hepdata.13638

Data on the mean multiplicity of strange hadrons produced in minimum bias proton--proton and central nucleus--nucleus collisions at momenta between 2.8 and 400 GeV/c per nucleon have been compiled. The multiplicities for nucleon--nucleon interactions were constructed. The ratios of strange particle multiplicity to participant nucleon as well as to pion multiplicity are larger for central nucleus--nucleus collisions than for nucleon--nucleon interactions at all studied energies. The data at AGS energies suggest that the latter ratio saturates with increasing masses of the colliding nuclei. The strangeness to pion multiplicity ratio observed in nucleon--nucleon interactions increases with collision energy in the whole energy range studied. A qualitatively different behaviour is observed for central nucleus--nucleus collisions: the ratio rapidly increases when going from Dubna to AGS energies and changes little between AGS and SPS energies. This change in the behaviour can be related to the increase in the entropy production observed in central nucleus-nucleus collisions at the same energy range. The results are interpreted within a statistical approach. They are consistent with the hypothesis that the Quark Gluon Plasma is created at SPS energies, the critical collision energy being between AGS and SPS energies.

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Pion multiplicity in nuclear collisions

Gazdzicki, M. ; Roehrich, D. ;
Z.Phys. C65 (1995) 215-223, 1995.
Inspire Record 398172 DOI 10.17182/hepdata.14107
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Proton-proton collisions at 3.5 GeV

Piserchio, R.J. ; Kalbach, R.M. ;
Nuovo Cim. 26 (1962) 729-739, 1962.
Inspire Record 1185010 DOI 10.17182/hepdata.37708
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Proton-proton collisions at 19.8 GeV/c

Abraham, F.F. ; Kalbach, R.M. ;
Nuovo Cim. 26 (1962) 717-728, 1962.
Inspire Record 1185008 DOI 10.17182/hepdata.37715

Elastic and inelastic 19.8 GeV/c proton-proton collisions in nuclear emulsion are examined using an external proton beam of the CERN Proton Synchrotron. Multiple scattering, blob density, range and angle measurements give the momentum spectra and angular distributions of secondary protons and pions. The partial cross-sections corresponding to inelastic interactions having two, four, six, eight, ten and twelve charged secondaries are found to be, respectively, (16.3±8.4) mb, (11.5 ± 6.0) mb, (4.3 ± 2.5) mb, (1.9 ± 1.3) mb, (0.5 ± 0.5) mb and (0.5±0.5)mb. The elastic cross-section is estimated to be (4.3±2.5) mb. The mean charged meson multiplicity for inelastic events is 3.7±0.5 and the average degree of inelasticity is 0.35±0.09. Strong forward and backward peaking is observed in the center-of-mass system for both secondary charged pions and protons. Distributions of energy, momentum and transverse momentum for identified charged secondaries are presented and compared with the results of work at other energies and with the results of a statistical theory of proton-proton collisions.

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Hadron spectra in hadron - nucleus collisions

Armutliiski, D. ; Baatar, Ts. ; Batsaikhan, Ts. ; et al.
No Journal Information, 1991.
Inspire Record 319258 DOI 10.17182/hepdata.38698
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Subthreshold K+ production in proton nucleus collisions

Debowski, M. ; Barth, R. ; Boivin, M. ; et al.
Z.Phys. A356 (1996) 313-325, 1996.
Inspire Record 432858 DOI 10.17182/hepdata.16477

Double differential K+cross sections have been measured in p+C collisions at 1.2, 1.5 and 2.5 GeV beam energy and in p+Pb collisions at 1.2 and 1.5 GeV. The K+ spectrum taken at 2.5 GeV can be reproduced quantitatively by a model calculation which takes into account first chance proton-nucleon collisions and internal momentum with energy distribution of nucleons according to the spectral function. At 1.2 and 1.5 GeV beam energy the K+ data excess significantly the model predictions for first chance collisions. When taking secondary processes into account the results of the calculations are in much better agreement with the data.

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Proton-Proton Collisions at 4.2 Bev

Blue, M.H. ; Lord, J.J. ; Parks, J.G. ; et al.
Phys.Rev. 125 (1962) 1386-1393, 1962.
Inspire Record 944984 DOI 10.17182/hepdata.26806
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Pion pair production in photon-photon collisions

Blinov, A.E. ; Blinov, V.E. ; Bondar, A.E. ; et al.
Z.Phys. C53 (1992) 33-39, 1992.
Inspire Record 335707 DOI 10.17182/hepdata.14772
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Subthreshold K+ production in heavy ion collisions

Julien, J. ; Lebrun, D. ; Mougeot, A. ; et al.
Phys.Lett. B264 (1991) 269-273, 1991.
Inspire Record 304290 DOI 10.17182/hepdata.29376
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Strange meson enhancement in Pb Pb collisions

The NA44 collaboration Bearden, I. ; Boggild, H. ; Boissevain, J. ; et al.
Phys.Lett. B471 (1999) 6-12, 1999.
Inspire Record 504074 DOI 10.17182/hepdata.31360
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Kaon Pair Production in Proton--Proton Collisions

The ANKE collaboration Maeda, Y. ; Hartmann, M. ; Keshelashvili, I. ; et al.
Phys.Rev. C77 (2008) 015204, 2008.
Inspire Record 763646 DOI 10.17182/hepdata.25173

The differential and total cross sections for kaon pair production in the pp->ppK+K- reaction have been measured at three beam energies of 2.65, 2.70, and 2.83 GeV using the ANKE magnetic spectrometer at the COSY-Juelich accelerator. These near-threshold data are separated into pairs arising from the decay of the phi-meson and the remainder. For the non-phi selection, the ratio of the differential cross sections in terms of the K-p and K+p invariant masses is strongly peaked towards low masses. This effect can be described quantitatively by using a simple ansatz for the K-p final state interaction, where it is seen that the data are sensitive to the magnitude of an effective K-p scattering length. When allowance is made for a small number of phi events where the K- rescatters from the proton, the phi region is equally well described at all three energies. A very similar phenomenon is discovered in the ratio of the cross sections as functions of the K-pp and K+pp invariant masses and the identical final state interaction model is also very successful here. The world data on the energy dependence of the non-phi total cross section is also reproduced, except possibly for the results closest to threshold.

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Near threshold eta meson production in proton proton collisions

Smyrski, J. ; Wuestner, P. ; Budzanowski, A. ; et al.
Phys.Lett. B474 (2000) 182-187, 2000.
Inspire Record 512406 DOI 10.17182/hepdata.28056

The production of eta mesons has been measured in the proton-proton interaction close to the reaction threshold using the COSY-11 internal facility at the cooler synchrotron COSY. Total cross sections were determined for eight different excess energies in the range from 0.5 MeV to 5.4 MeV. The energy dependence of the total cross section is well described by the available phase-space volume weighted by FSI factors for the proton-proton and proton-eta pairs.

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eta meson production in p d and p p collisions

Chiavassa, E. ; Dellacasa, G. ; De Marco, N. ; et al.
Phys.Lett. B337 (1994) 192-195, 1994.
Inspire Record 384615 DOI 10.17182/hepdata.28780
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Vector boson production in hadron nuclear collisions. FNAL-597 experiment

Walker, W.D. ; Whitmore, J. ; Toothacker, W.S. ; et al.
Phys.Lett. B255 (1991) 155-158, 1991.
Inspire Record 317003 DOI 10.17182/hepdata.29509
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Inclusive $D^{*\pm}$ production in photon-photon collisions

The TPC/Two-Gamma collaboration Alston-Garnjost, M. ; Avery, R.E. ; Barker, A.R. ; et al.
Phys.Lett. B252 (1990) 499-504, 1990.
Inspire Record 299662 DOI 10.17182/hepdata.29510
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Observation of Charmed Mesons in Photon-photon Collisions

The JADE collaboration Bartel, W. ; Becker, L. ; Felst, R. ; et al.
Phys.Lett. B184 (1987) 288-292, 1987.
Inspire Record 235696 DOI 10.17182/hepdata.30214
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Exclusive Proton - Anti-proton Production in Two Photon Collisions

The TASSO collaboration Brandelik, R. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett. B108 (1982) 67-70, 1982.
Inspire Record 167679 DOI 10.17182/hepdata.31000
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Threshold hyperon production in proton-proton collisions at COSY-11

Rozek, T. ; Grzonka, D. ; Adam, H.-H. ; et al.
Phys.Lett. B643 (2006) 251-256, 2006.
Inspire Record 722758 DOI 10.17182/hepdata.31512

Sigma+ hyperon production was measured at the COSY-11 spectrometer via the p p --> n K+ Sigma+ reaction at excess energies of Q = 13 MeV and Q = 60 MeV. These measurements continue systematic hyperon production studies via the p p --> p K+ Lambda/Sigma0 reactions where a strong decrease of the cross section ratio close-to-threshold was observed. In order to verify models developed for the description of the Lambda and Sigma0 production we have performed the measurement on the Sigma+ hyperon and found unexpectedly that the total cross section is by more than one order of magnitude larger than predicted by all anticipated models. After the reconstruction of the kaon and neutron four momenta, the Sigma+ is identified via the missing mass technique. Details of the method and the measurement will be given and discussed in view of theoretical models.

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Forward K+ production in subthreshold pA collisions at 1.0-GeV

The ANKE collaboration Koptev, V. ; Buescher, Markus ; Junghans, H. ; et al.
Phys.Rev.Lett. 87 (2001) 022301, 2001.
Inspire Record 556676 DOI 10.17182/hepdata.31765

K+ meson production in pA (A = C, Cu, Au) collisions has been studied using the ANKE spectrometer at an internal target position of the COSY-Juelich accelerator. The complete momentum spectrum of kaons emitted at forward angles, theta < 12 degrees, has been measured for a beam energy of T(p)=1.0 GeV, far below the free NN threshold of 1.58 GeV. The spectrum does not follow a thermal distribution at low kaon momenta and the larger momenta reflect a high degree of collectivity in the target nucleus.

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Target associated particle production in ultrarelativistic nucleus-nucleus collisions

Sengupta, K. ; Jain, P.L. ; Singh, G. ;
Mod.Phys.Lett. A6 (1991) 29-39, 1991.
Inspire Record 316958 DOI 10.17182/hepdata.37873
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Bottom production in $\pi^{-}$ - Be collisions at 515-GeV/c

The E672/E706 collaboration Jesik, R. ; Abramov, V. ; Antipov, Yu. ; et al.
Phys.Rev.Lett. 74 (1995) 495-498, 1995.
Inspire Record 374151 DOI 10.17182/hepdata.42447
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Inclusive jet production in $p\bar{p}$ collisions

The D0 collaboration Abbott, B. ; Abdesselam, A. ; Abolins, M. ; et al.
Phys.Rev.Lett. 86 (2001) 1707-1712, 2001.
Inspire Record 536691 DOI 10.17182/hepdata.42948

We report a new measurement of the pseudorapidity (eta) and transverse-energy (Et) dependence of the inclusive jet production cross section in pbar b collisions at sqrt(s) = 1.8 TeV using 95 pb**-1 of data collected with the DZero detector at the Fermilab Tevatron. The differential cross section d^2sigma/dEt deta is presented up to |eta| = 3, significantly extending previous measurements. The results are in good overall agreement with next-to-leading order predictions from QCD and indicate a preference for certain parton distribution functions.

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Agakishiev, G.N. ; Iovchev, K.I. ; Kladnitskaya, E.N. ; et al.
No Journal Information, 1989.
Inspire Record 286451 DOI 10.17182/hepdata.38757
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On pion production intensities in hadron - nucleus collisions

Strugalska-Gola, E. ; Strugalski, Z. ; Sredniawa, B. ; et al.
No Journal Information, 1996.
Inspire Record 428911 DOI 10.17182/hepdata.39365
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Observation of Exclusive Electron-Positron Production in Hadron-Hadron Collisions

The CDF collaboration Abulencia, A. ; Adelman, Jahred A. ; Affolder, T. ; et al.
Phys.Rev.Lett. 98 (2007) 112001, 2007.
Inspire Record 732591 DOI 10.17182/hepdata.42744

We present the first observation of exclusive $e^+e^-$ production in hadron-hadron collisions, using $p\bar{p}$ collision data at \mbox{$\sqrt{s}=1.96$ TeV} taken by the Run II Collider Detector at Fermilab, and corresponding to an integrated luminosity of \mbox{532 pb$^{-1}$}. We require the absence of any particle signatures in the detector except for an electron and a positron candidate, each with transverse energy {$E_T>5$ GeV} and pseudorapidity {$|\eta|<2$}. With these criteria, 16 events are observed compared to a background expectation of {$1.9\pm0.3$} events. These events are consistent in cross section and properties with the QED process \mbox{$p\bar{p} \to p + e^+e^- + \bar{p}$} through two-photon exchange. The measured cross section is \mbox{$1.6^{+0.5}_{-0.3}\mathrm{(stat)}\pm0.3\mathrm{(syst)}$ pb}. This agrees with the theoretical prediction of {$1.71 \pm 0.01$ pb}.

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