Date

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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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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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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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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CHARACTERISTICS OF CUMULATIVE LAMBDA HYPERONS PRODUCED IN NUCLEUS-NUCLEUS COLLISIONS

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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Subthreshold anti-proton and K- production in heavy ion collisions

Schroter, A. ; Berdermann, E. ; Geissel, H. ; et al.
Z.Phys. A350 (1994) 101-113, 1994.
Inspire Record 372238 DOI 10.17182/hepdata.16507
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Pion Pair Production From $\gamma \gamma$ Collisions at {PEP}

Smith, J.R. ; Burke, D.L. ; Abrams, G.S. ; et al.
Phys.Rev. D30 (1984) 851, 1984.
Inspire Record 195739 DOI 10.17182/hepdata.23582
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Collective expansion in high-energy heavy ion collisions

The NA44 collaboration Bearden, I.G. ; Boggild, H. ; Boissevain, J. ; et al.
Phys.Rev.Lett. 78 (1997) 2080-2083, 1997.
Inspire Record 426801 DOI 10.17182/hepdata.52345
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Pion and Kaon Pair Production in Photon-Photon Collisions

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.Lett. 57 (1986) 404, 1986.
Inspire Record 228072 DOI 10.17182/hepdata.20204
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Production of Four Prong Final States in Photon-photon Collisions

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev. D37 (1988) 28, 1988.
Inspire Record 261630 DOI 10.17182/hepdata.3824
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Sigma production in p-p collisions at 5 GeV/ c

Sondhi, I. ;
Phys.Lett. B26 (1968) 645-648, 1968.
Inspire Record 1389658 DOI 10.17182/hepdata.29305

The cross section for the reaction pp → Σ + K + n at 5 GeV/ c is measured to be 48.1 ± 3.5 μ b. The KΣ mass spectrum shows an enhancement at 1.86 GeV, which may due to the Δ (1920) resonance. Adequacy of the one-pion exchange model for the reaction is discussed. The cross section for the reaction pp → Σ + K o p is found to be 24.9 ± 2.3 μ b.

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Lambda hyperons in 2A-GeV Ni + Cu collisions

The EOS collaboration Justice, M. ; Albergo, S. ; Bieser, F. ; et al.
Phys.Lett. B440 (1998) 12-19, 1998.
Inspire Record 447685 DOI 10.17182/hepdata.31414

A sample of Lambda's produced in 2 A*GeV Ni + Cu collisions has been obtained with the EOS Time Projection Chamber at the Bevalac. Low background in the invariant mass distribution allows for the unambiguous demonstration of Lambda directed flow. The transverse mass spectrum at mid-rapidity has the characteristic shoulder-arm shape of particles undergoing radial transverse expansion. A linear dependence of Lambda multiplicity on impact parameter is observed, from which a total Lambda + Sigma^0 production cross section of $112 +/- 24 mb is deduced. Detailed comparisons with the ARC and RVUU models are made.

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Kaon production in 200-GeV/nucleon nucleus-nucleus collisions

The HELIOS collaboration Akesson, T. ; Almehed, S. ; Angelis, A.L.S. ; et al.
Phys.Lett. B296 (1992) 273-278, 1992.
Inspire Record 338072 DOI 10.17182/hepdata.28995
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Hyperon production in proton - sulphur collisions at 200-GeV/c

The WA94 collaboration Abatzis, S. ; Andersen, E. ; Andrighetto, A. ; et al.
Phys.Lett. B400 (1997) 239-244, 1997.
Inspire Record 427129 DOI 10.17182/hepdata.12547
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Measurement of $K^+ K^-$ Production in $\gamma \gamma$ Collisions

The ARGUS collaboration Albrecht, H. ; Glaser, R. ; Harder, G. ; et al.
Z.Phys. C48 (1990) 183-190, 1990.
Inspire Record 284561 DOI 10.17182/hepdata.15151
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PION PRODUCTION AT 180-degrees IN NUCLEUS-NUCLEUS COLLISIONS

Chessin, Stephen Alan ;
PhD Thesis, 1983.
Inspire Record 196037 DOI 10.17182/hepdata.38160
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The Near-threshold production of phi mesons in pp collisions

Hartmann, M. ; Maeda, Y. ; Keshelashvilli, I. ; et al.
Phys.Rev.Lett. 96 (2006) 242301, 2006.
Inspire Record 713863 DOI 10.17182/hepdata.41806

The pp->pp phi reaction has been studied at the Cooler Synchrotron COSY-Juelich, using the internal beam and ANKE facility. Total cross sections have been determined at three excess energies epsilon near the production threshold. The differential cross section closest to threshold at epsilon=18.5 MeV exhibits a clear S-wave dominance as well as a noticeable effect due to the proton-proton final state interaction. Taken together with data for pp omega-production, a significant enhancement of the phi/omega ratio of a factor 8 is found compared to predictions based on the Okubo-Zweig-Iizuka rule.

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Inclusive charged hadron production in two photon collisions at LEP

The L3 collaboration Achard, P. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett. B554 (2003) 105-114, 2003.
Inspire Record 605973 DOI 10.17182/hepdata.48854

Inclusive charged hadron production, e+e- -> e+e- h+- X, is studied using 414 pb-1 of data collected at LEP with the L3 detector at centre-of-mass energies between 189 and 202 GeV. Single particle inclusive differential cross sections are measured as a function of the particle transverse momentum, pt, and pseudo-rapidity, eta. For p_t &lt; 1.5 GeV, the data are well described by an exponential, typical of soft hadronic processes. For higher pt, the onset of perturbative QCD processes is observed. The pi+- production cross section for pt > 5 GeV is much higher than the NLO QCD predictions.

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Inclusive lambda production in two photon collisions at LEP

The L3 collaboration Achard, P. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett. B586 (2004) 140-150, 2004.
Inspire Record 637287 DOI 10.17182/hepdata.48849

The reactions e^+e^- -> e^+e^- Lambda X and e^+e^- -> e^+e^- Lambda X are studied using data collected at LEP with the L3 detector at centre-of-mass energies between 189 and 209 GeV. Inclusive differential cross sections are measured as a function of the lambda transverse momentum, p_t, and pseudo-rapidity, eta, in the ranges 0.4 GeV < p_t < 2.5 GeV and |\eta| < 1.2. The data are compared to Monte Carlo predictions. The differential cross section as a function of p_t is well described by an exponential of the form A exp (- p_t / <p_t>)$.

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Multiplicity dependence of strangeness production in S + Pb collisions at 200-GeV/c per nucleon

The NA36 collaboration Andersen, E. ; Blaes, R. ; Brom, J.M. ; et al.
Phys.Lett. B316 (1993) 603-607, 1993.
Inspire Record 364810 DOI 10.17182/hepdata.28817
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Charged particle production in S S collisions at 200-GeV/c per nucleon

The WA94 collaboration Andrighetto, A. ; Antinori, F. ; Bayes, A.C. ; et al.
Phys.Lett. B412 (1997) 148-154, 1997.
Inspire Record 460283 DOI 10.17182/hepdata.28242
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Production of xi- and antixi+ particles in k+ p collisions at 12.7 gev/c

Stone, S.L. ; Berlinghieri, J.C. ; Bromberg, C. ; et al.
Phys.Lett. B32 (1970) 515-518, 1970.
Inspire Record 63098 DOI 10.17182/hepdata.28710
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