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Pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV: Evidence for the onset of deconfinement

The NA49 collaboration Alt, C. ; Anticic, T. ; Baatar, B. ; et al.

Phys.Rev.C 77 (2008) 024903, 2008.

Inspire Record 762554 DOI 10.17182/hepdata.25169

Results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies. A rapid change of the energy dependence is observed around 30A GeV for the yields of pions and kaons as well as for the shape of the transverse mass spectra. The change is compatible with the prediction that the threshold for production of a state of deconfined matter at the early stage of the collisions is located at low SPS energies.

13 data tables

Table 1

Transverse mass spectra for pion production in the central rapidity region for collisions at 20 GeV per nucleon.

Table 2

Transverse mass spectra for pion production in the central rapidity region for collisions at 30 GeV per nucleon.

Table 3

Transverse mass spectra for kaon production in the central rapidity region for collisions at 20 GeV per nucleon.

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Photoproduction of $\phi$ Mesons by Linearly Polarized Photons of Energy 20-{GeV} to 40-{GeV} and Further Evidence for a Photoproduced High Mass $K K$ Enhancement

The Omega Photon collaboration Atkinson, M. ; Axon, T.J. ; Barberis, D. ; et al.

Z.Phys.C 27 (1985) 233, 1985.

Inspire Record 204590 DOI 10.17182/hepdata.16067

A study of ϕ-meson photoproduction by partially polarized photons of energy 20–40 GeV is reported. The production mechanism is found to conserves-channel helicity and to proceed via natural-parity exchange in thet channel. In the photoproduction of high-massK+K− states with photons of energy 20–70 GeV, there is evidence for an enhancement at a mass of 1.76 GeV with width 0.08 GeV.

4 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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THE REACTION P P ---> (LAMBDA0 K+) P AT 50-GEV/C AND 30-GEV/C: PARTIAL WAVE ANALYSIS, DECK MODEL AND DOUBLE REGGE EXCHANGE

Cleland, W.E. ; Delfosse, A. ; Dorsaz, P.-A. ; et al.

Nucl.Phys.B 239 (1984) 27-51, 1984.

Inspire Record 205379 DOI 10.17182/hepdata.33884

We have obtained a sample of 20 465 (2201) events in the channel pp→ ( Λ 0 K + )p at 50 (30) GeV/ c incident momentum with Geneva-Lausanne spectrometer at the CERN SPS. In this analysis we investigate: 1. (i) the production of N ∗ (I = 1 2 ) states in the mass region 1.6 ⩽ M ( Λ 0 K + ) ⩽ 2.6 GeV and momentum transfer 0.06 ⩽ | t | 1.0 (GeV/ c ) 2 , by studing the amplitudes and phases from a moment analysis of the decay angular distribution; 2. (ii) the contribution of the K-exchange Deck model for M ( Λ 0 K + < 2.22 GeV; 3. (iii) the double Regge exchange phenomenology for s Λ 0 K + > 5 GeV 2 and s Λ 0 K + p > 5 GeV 2 .

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

EVIDENCE FOR RESONANT STRUCTURES IN THE LAMBDA anti-p SYSTEM

The Bari-Birmingham-CERN-Milan-Paris-Pavia collaboration Armstrong, T. ; Baubillier, M. ; Bloodworth, I.J. ; et al.

Nucl.Phys.B 227 (1983) 365-386, 1983.

Inspire Record 191867 DOI 10.17182/hepdata.33928

An analysis of the Λ p p system produced forward in the reaction K p → Λ p p at 18.5 GeV/ c is presented. The data come from an experiment using the CERN Ω′ spectrometer. Structures are observed in the Λ p mass spectrum and in the double moments H LMlm describing the decay of the Λ p system and the subsequent Λ decay, for L ⩽ 8. A partial wave analysis interprets these structures as resonances of spin parities 2 − and 3 + , masses and widths M = 2200 ± 40 MeV, Γ = 150 ± 30 MeV and M = 2330 ± 40 MeV, Γ = 150 ± 30 MeV respectively.

3 data tables

Table 1

UNCORRECTED DISTRIBUTION.

Table 2

FULLY CORRECTED CROSS SECTION.

Table 3

CROSS SECTIONS FOR RESONANCES. BREIT WIGNER FITTED WITH NO ADDITIONAL BACKGROUND.

A Study of the Reaction $\pi^- p \to \phi \phi n$ at 16-{GeV}/$c$

The Aachen-Bari-Bonn-CERN-Glasgow-Liverpool-Milan collaboration Armstrong, T.A. ; Baccari, B. ; Booth, P.S.L. ; et al.

Nucl.Phys.B 196 (1982) 176-188, 1982.

Inspire Record 165251 DOI 10.17182/hepdata.34217

The reaction π − p → φφ n has been isolated at 16 GeV/ c and its cross section determined to be 40 ± 10 nb. The φφ mass spectrum shows a threshold enhancement between 2.1 and 2.5 GeV. A successful description of the angular content of the φφ system requires two interferingss J P = 2 + states.

2 data tables

Table 1

No description provided.

Table 2

SLOPE OF DIFFERENTIAL TP(P=3,P=2) DISTRIBUTION.

Photoproduction of $K^+ K^-$ Pairs on Hydrogen at Photon Energies of 20-{GeV} to 36-{GeV}

The Bonn-CERN-Ecole Poly-Glasgow-Lancaster-Manchester-Orsay-Paris-Rutherford-Sheffield collaboration Aston, D. ; Atkinson, M. ; Bailey, R. ; et al.

Nucl.Phys.B 172 (1980) 1-12, 1980.

Inspire Record 153022 DOI 10.17182/hepdata.34516

The reaction γ p→K + K − p has been investigated with photons in the energy range of 20< E γ <36 GeV and with K + K − pairs in the mass range of M K + K − <2.0 GeV. The production of the φ(1019) contributes with a cross section σ ( γ p → φ p) × BR( φ →K + K − ) = 240±6 nb with an additional systematic error of ±20 nb. In the higher mass range of 1.05< M K + K − <2.0 GeV the production of K + K − pairs yields a cross section σ ( γ p→K + K − p) = 160±8 nb with an additional systematic error of +40 −30 nb.

3 data tables

Table 1

No description provided.

Table 2

K+ K- PRODUCTION ABOVE PHI MASS.

Table 3

No description provided.

STUDY OF THE UPSILON (9.46) MESON IN ELECTRON - POSITRON ANNIHILATIONS

Darden, C.W. ; Hasemann, H. ; Krolzig, A. ; et al.

Phys.Lett.B 80 (1979) 419-422, 1979.

Inspire Record 145168 DOI 10.17182/hepdata.27358

New data for the reaction e + e − →ϒ(9.46) have been obtained using the DASP detector at the DORIS storage ring. The electronic width Γ ee is (1.5±0.4) keV. The branching ratio for the decay into muon pairs is (2.5 ± 2.1)%. Energy spectra for inclusive production of hadrons are given.

2 data tables

Table 1

VISIBLE HADRONIC TOTAL CROSS SECTION.

Table 2

INVARIANT INCLUSIVE PRODUCTION CROSS SECTION E*D3(SIG)/DP**3 BOTH ON AND OFF THE UPSILON(9.46) RESONANCE. NO SIGNIFICANT DIFFERENCE IN EXPONENTIAL SLOPE AS A FUNCTION OF PARTICLE ENERGY E(P=3).

A Comparison of K+- n Charge Exchange Reactions at 8.5-GeV/c and 13-GeV/c

Gilchriese, M.G.D. ; Dunwoodie, W.M. ; Fieguth, T.H. ; et al.

Phys.Rev.Lett. 40 (1978) 6, 1978.

Inspire Record 120363 DOI 10.17182/hepdata.20886

The cross sections for the line-reversed reaction pairs K+n→K0p and K−p→K¯0n, and K+p→K0Δ++ and K−n→K¯0Δ− have been determined with high statistics and good relative normalization at 8.36 and 12.8 GeV/c in a spectrometer experiment at Stanford Linear Accelerator Center. The cross sections for the K+-induced reactions are larger than for the K−, contrary to the expectations of weakly-exchange-degenerate Regge-pole models. The ratio of the reaction cross sections is about the same as at lower energies and shows little change with momentum transfer.

4 data tables

Table 1

Axis error includes +- 11/11 contribution.

Table 2

Axis error includes +- 11/11 contribution.

Table 3

Axis error includes +- 11/11 contribution.

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Analysis of the Reaction K- p --> K- pi- pi+ p at 40-GeV/c

The CERN-Serpukhov Boson Spectrometer Group collaboration Antipov, Yu.M. ; Ascoli, G. ; Busnello, R. ; et al.

Nucl.Phys.B 86 (1975) 381-402, 1975.

Inspire Record 90643 DOI 10.17182/hepdata.32087

The reaction K − p → K − π − π + p has been measured at 25 and 40 GeV/ c at the Serpukhov Proton Accelerator. The production cross section at 25 and 40 GeV/ c as a function of momentum transfer and K ππ mass is presented, and results of the partial-wave analysis of the K ππ system yielding information about Q(1300), K ∗ (1400) and L(1770) mesons are discussed.

3 data tables

Table 1

No description provided.

Table 2

K** DEFINED BY 1.30 < M(K PI PI) < 1.54 GEV.

Table 3

L IS DEFINED AS THE 2- STATE WITH 1.6 < M(K PI PI) < 1.9 GEV.