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

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

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

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

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Charged pion production in 2-AGeV to 8-AGeV central Au + Au collisions.

The E-0895 collaboration Klay, J.L. ; Ajitanand, N.N. ; Alexander, J.M. ; et al.
Phys.Rev.C 68 (2003) 054905, 2003.
Inspire Record 622260 DOI 10.17182/hepdata.4989

Momentum spectra of charged pions over nearly full rapidity coverage from target to beam rapidity have been measured in the 0-5% most central Au+Au collisions in the beam energy range from 2 to 8 AGeV by the E895 Experiment. Using a thermal parameterization to fit the transverse mass spectra, rapidity density distributions are extracted. The observed spectra are compared with predictions from the RQMD v2.3 cascade model and also to a thermal model including longitudinal flow. The total 4$\pi$ yields of the charged pions are used to infer an initial state entropy produced in the collisions.

98 data tables

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Analyzing the features of pi- mesons and protons from A C interactions at a momentum of p = 4.2-GeV/c per projectile nucleon on the basis of the FRITIOF model.

Baatar, T. ; Bondarenko, A.I. ; Bondarenko, R.A. ; et al.
Phys.Atom.Nucl. 63 (2000) 839-844, 2000.
Inspire Record 533011 DOI 10.17182/hepdata.17089

The mean multiplicities of π− mesons and protons originating from pC, dC, αC, and CC interactions at a momentum of p=4.2 GeV/c per projectile nucleon and the distributions of these particles in kinematical variables are presented. These experimental distributions are compared with the corresponding predictions obtained on the basis of the FRITIOF model. It is shown that the FRITIOF version used in the present analysis describes satisfactorily our experimental data.

16 data tables

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Centrality dependence of pi+-, K+-, p and anti-p production from s(NN)**(1/2) = 130-GeV Au + Au collisions at RHIC.

The PHENIX collaboration Adcox, K. ; Adler, S.S. ; Ajitanand, N.N. ; et al.
Phys.Rev.Lett. 88 (2002) 242301, 2002.
Inspire Record 568437 DOI 10.17182/hepdata.19421

Identified pi^[+/-] K^[+/-], p and p-bar transverse momentum spectra at mid-rapidity in sqrt(s_NN)=130 GeV Au-Au collisions were measured by the PHENIX experiment at RHIC as a function of collision centrality. Average transverse momenta increase with the number of participating nucleons in a similar way for all particle species. The multiplicity densities scale faster than the number of participating nucleons. Kaon and nucleon yields per participant increase faster than the pion yields. In central collisions at high transverse momenta (p_T greater than 2 GeV/c), anti-proton and proton yields are comparable to the pion yields.

21 data tables

Transverse momentum spectra for PI+ in the midrapidity range for the centrality region 0 to 5 PCT. Errors are combined statistical and systematics.

Transverse momentum spectra for PI- in the midrapidity range for the centrality region 0 to 5 PCT. Errors are combined statistical and systematics.

Transverse momentum spectra for K+ in the midrapidity range for the centrality region 0 to 5 PCT. Errors are combined statistical and systematics.

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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.

33 data tables

The centrality of the collisions expressed as a percentage of the inelastic cross section (7.15nb), and the mean numbers of wounded nuclei.

The inverse slope parameter of the fitted transverse mass spectra.

The rapidity density averaged over the rapidity interval -0.6 to 0.6.

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Strange meson enhancement in Pb Pb collisions.

The NA44 collaboration Bearden, I. ; Bøggild, H. ; Boissevain, J. ; et al.
Phys.Lett.B 471 (1999) 6-12, 1999.
Inspire Record 504074 DOI 10.17182/hepdata.31360

The NA44 Collaboration has measured yields and differential distributions of K+, K-, pi+, pi- in transverse kinetic energy and rapidity, around the center-of-mass rapidity in 158 A GeV/c Pb+Pb collisions at the CERN SPS. A considerable enhancement of K+ production per pi is observed, as compared to p+p collisions at this energy. To illustrate the importance of secondary hadron rescattering as an enhancement mechanism, we compare strangeness production at the SPS and AGS with predictions of the transport model RQMD.

4 data tables

Inverse slope paramters of the (1/MT)*DN/DMT distribution.

Rapidity distributions for K+ and K- production.. Statistical and systematic errors added in quadrature.

Rapidity distributions for PI+ and PI- production.. Statistical and systematic errors added in quadrature.

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Study of the inclusive reaction Mg + Mg ---> pi- + X at a momentum of 4.3-GeV/c per incident nucleon

Chkhaidze, L. ; Dzhobava, T. ; Kharkhelauri, L. ; et al.
J.Phys.G 22 (1996) 641-651, 1996.
Inspire Record 431133 DOI 10.17182/hepdata.43780

A detailed study of pion production in central Mg - Mg collisions at a momentum of 4.3 GeV/c per incident nucleon was carried out using the GIBS set-up. It has been shown that the dependence of the average kinematical characteristics ( and ) of mesons on multiplicity differs from that for NN collisions at the same energy, which is due to nuclear effects. The temperatures of mesons have been estimated using two different selection criteria: in the rapidity interval and at angles in the CMS. A satisfactory fit for mesons can be achieved by using a form involving two temperatures and . The relative yield of the high-temperature component is . The results obtained by the intranuclear cascade model CASIMIR coincide with the experimental data estimated with both methods. From the analysis of angular distributions of mesons the anisotropy coefficient a was obtained. The anisotropy coefficient increases linearly with the kinetic energy (in the CMS). CASIMIR reproduces the increase of a with , but the slope is less steep than from experimental results.

2 data tables

The average kinematical characteristics of the PI- production.

The mean YRAP and its dispersion in various PT intervals.


Hadron yields and hadron spectra from the NA49 experiment

The NA49 collaboration Jones, P.G. ; Afanasiev, S.V. ; Alber, T. ; et al.
Nucl.Phys.A 610 (1996) 188C-199C, 1996.
Inspire Record 432742 DOI 10.17182/hepdata.36468

Preliminary inclusive spectra of negative hadrons, net protons and neutral strange particles are presented, measured by the NA49 experiment in central Pb+Pb collisions at 158 GeV per nucleon. Comparison of their yields with those from the lighter S+S system suggests that the yields scale approximately with the number of participating nucleons.

4 data tables

CENTRAL COLLISIONS, PRELIMINARY DATA.

CENTRAL COLLISIONS, PRELIMINARY DATA.

CENTRAL COLLISIONS, PRELIMINARY DATA.

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Hadron distributions: Recent results from the CERN experiment NA44

The NA44 collaboration Xu, Nu ; Bearden, I.G. ; Bøggild, H. ; et al.
Nucl.Phys.A 610 (1996) 175C-187C, 1996.
Inspire Record 432743 DOI 10.17182/hepdata.36469

Proton distributions at midrapidity have been measured for 158A·GeV Pb+Pb collisions in the focusing spectrometer experiment NA44 at CERN. A high degree of nuclear stopping is found in the truly heavy ion collisions. Systematic results of single particle transverse momentum distributions of pions, kaons, and protons, of 200A·GeV S+S and 158A·GeV Pb+Pb central collisions will be addressed within the context of thermalization. By comparing these data with thermal and transport models, freeze-out parameters such as the temperature parameter T fo and mean collective flow velocity 〈β〉 are extracted. Preliminary results of the particle ratios of K − K + and p p are discussed in the context of cascade models of RQMD and VENUS.

1 data table

CENTRAL COLLISIONS: SIG(TRIG)/SIG(GEOM)=10%.


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

Transverse mass spectra of pions, kaons, and protons from the symmetric heavy-ion collisions 200 A GeV S+S and 158 A GeV Pb+Pb, measured in the NA44 focusing spectrometer at CERN, are presented. The mass dependence of the slope parameters provides evidence of collective transverse flow from expansion of the system in heavy-ion induced central collisions.

3 data tables

(1/MT)*d(N)/d(MT) = A *exp(-MT/SLOPE).

(1/MT)*d(N)/d(MT) = A *exp(-MT/SLOPE).

The SLOPE from the parameterization of (1/MT)*d(N)/d(MT) = A*exp(-MT/SLOPE)is fitted as follows SLOPE = CONST(C=1) + M(hadron)*CONST(C=2)**2.


Anti-proton production in 14.6-A/GeV/c Si + A collisions

The E-802 collaboration Abbott, T. ; Akiba, Y. ; Beavis, D. ; et al.
Phys.Lett.B 271 (1991) 447-452, 1991.
Inspire Record 318378 DOI 10.17182/hepdata.29302

Antiproton production cross sections have been measured for minimum bias and central Si+Al and Si+Au collisions at 14.6 A GeV c . The data presented cover the range of transverse momentum from 0.3 to 1.2 GeV c and lab rapidities from 1.1 to 1.7 units. The relative p π − and p K − yields are found to be the smallest for the heaviest system measured, central Si+Au collisions. For these collisions, the p π − ratio, determined from integrated yields for 1.1⩽ y ⩽1.7, is (0.84±0.07)×10 −3 . In the same rapidity interval, the average antiproton inverse m ⊥ slope is 141±14 MeV for central Si+Al and central Si+Au collisions.

2 data tables

Definition of the CENTRAL and MINIMUM BIAS events see text.

Definition of the CENTRAL and MINIMUM BIAS events see text.


The Temperatures of protons and pi- mesons in central nucleus-nucleus interactions at a momentum of 4.5-GeV/c per incident nucleon

Chkhaidze, L. ; Dzhobava, T. ; Kharkhelauri, L. ; et al.
Z.Phys.C 54 (1992) 179-183, 1992.
Inspire Record 339571 DOI 10.17182/hepdata.14709

An estimate of the temperature of protons andπ− mesons in central He−Li, He−C, C−C, C−Ne, C−Cu, C−Pb, O−Pb, Mg−Mg interactions is presented. The results indicate an increase of the proton temperature with increasing mass numbers of projectile and target nuclei (Ap,AT) fromTp=(118±3) MeV for He−Li toTp=(141±2) MeV for C−Pb. The temperature ofπ− mesons does not depend onAP,AT andTπ≃95 MeV. A satisfactory fit forπ− mesons in C−Cu, C−Pb, O−Pb, Mg−Mg collisions can be achieved by using a form involving two temperatures,T1 andT2. The relative yield of the high temperature component (T2) is ≅24% for C−Cu, C−Pb, and Mg−Mg interactions. The observed results forTP in C−Ne, C−Cu and C−Pb collisions are consistent with the prediction of the thermodynamic hagedorn model.

4 data tables

for C-CU and C-PB YRAP=0.3-1.7.

THE D(N)/D(PT) distribution has been fitted by the form: PT*ET*K1(SLOPE*ET), where K1 is Mac-Donaldis function. for C-CU and C-PB YRAP=0.3-1.7.

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Rapidity and transverse momentum distributions in 6.4-TeV S + Pb interactions from CERN EMU05 experiments. EMU-005 experiment

Iyono, A. ; Takahashi, Y. ; Gregory, J.C. ; et al.
Nucl.Phys.A 544 (1992) 455C-458C, 1992.
Inspire Record 343252 DOI 10.17182/hepdata.36672

Mixed transverse(P T ) momentum and rapidity distributions of charged particles produced in 200 GeV/AMU heavy ion collisions are obtained with Magnetic-Interferometric-Emulsion-Chamber ( MAGIC ) by CERN-EMU05 experiments. The P T spectra at different rapidity regions showed no anomalous enhancement of low P T components over a conventional, single exponential function with slope values ranging from 160 to 200 MeV/c.

1 data table

EVENTS SELECTED FOR THE ANALYSIS ARE THOSE WITH CHARGED MULTIPLICITY MORE THAN 400 FOR CENTRAL S+PB COLLISIONS.


Mass dependence of pion production in heavy ion collisions near, but below threshold

Miller, J. ; Krebs, G.F. ; Panetta, J. ; et al.
Phys.Lett.B 314 (1993) 7-12, 1993.
Inspire Record 357754 DOI 10.17182/hepdata.38101

We have measured the inclusive cross section for production of negative pions near mid-rapidity in 20 Ne + NaF , 139 La + 139 La and 197 Au + 197 Au collisions at E = 183 and 236 MeV/u. Au + Au is the heaviest system from which subthreshold pion production has been measured to date. The dependence of the pion cross section on pion energy, beam energy and associated charged particle multiplicity is consistent with previous results both above and below threshold. The dependence of the cross section on the mass of the colliding system varies only slightly as the beam energy is reduced below threshold, in contrast to some previous measurements. Comparison with theory suggests that at these energies the pion production process is still dominated by nucleon-nucleon collisions.

2 data tables

No description provided.

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Production of pi+-, K+-, p, and anti-p in relativistic Au + Pt, Si + Pt, and p + Pt collisions

The E886 collaboration Diebold, G.E. ; Bassalleck, B. ; Burger, T. ; et al.
Phys.Rev.C 48 (1993) 2984-2994, 1993.
Inspire Record 364483 DOI 10.17182/hepdata.26015

During the recent commissioning of Au beams at the Brookhaven Alternating Gradient Synchrotron facility, experiment 886 measured production cross sections for π±, K±, p, and p¯ in minimum bias Au+Pt collisions at 11.5A GeV/c. Invariant differential cross sections, Ed3σ/dp3, were measured at several rigidities (p/Z≤1.8 GeV/c) using a 5.7° (fixed-angle) focusing spectrometer. For comparison, particle production was measured in minimum bias Si+Pt collisions at 14.6A GeV/c using the same apparatus and in p+Pt collisions at 12.9 GeV/c using a similar spectrometer at KEK. When normalized to projectile mass, Aproj, the measured π± and K± cross sections are nearly equal for the p+Pt and Si+Pt reactions. In contrast to this behavior, the π− cross section measured in Au+Pt shows a significant excess beyond Aproj scaling of the p+Pt measurement. This enhancement suggests collective phenomena contribute significantly to π− production in the larger Au+Pt colliding system. For the Au+Pt reaction, the π+ and K+ yields also exceed Aproj scaling of p+Pt collisions. However, little significance can be attributed to these excesses due to larger experimental uncertainties for the positive rigidity Au beam measurements. For antiprotons, the Si+Pt and Au+Pt cross sections fall well below Aproj scaling of the p+Pt yields indicating a substantial fraction of the nuclear projectile is ineffective for p¯ production. Comparing with p+Pt multiplicities, the Si+Pt and Au+Pt antiproton yields agree with that expected solely from ‘‘first’’ nucleon-nucleon collisions (i.e., collisions between previously unstruck nucleons). In light of expected p¯ annihilation in the colliding system, such projectile independence is unexpected without additional (projectile dependent) sources of p¯ production. In this case, the data indicate an approximate balance exists between absorption and additional sources of antiprotons. This balance is remarkable given the wide range of projectile mass spanned by these measurements.

13 data tables

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Meson production in p + U, O + U and S + U interactions at 200-GeV/nucleon.

The NA38 collaboration Abreu, M.C. ; Baglin, C. ; Baldisseri, A. ; et al.
Z.Phys.C 55 (1992) 365-371, 1992.
Inspire Record 344266 DOI 10.17182/hepdata.14583

Meson production in proton, oxygen and sulphur interactions with uranium targets at 200 GeV/nucleon is studied. We measure the inclusive meson cross-section d σ/dPT2 and its evolution fromp+U to S+U. The cross-section fitted with an exponential gives an inverse slopePT0 of the order of 210 MeV/c. As a function of the neutral transverse energy,PT0 values show a slight rise followed by a plateau. The normalized difference (σ+−σ−)/σ− between positive and negative meson cross-sections is found to increase withET.

6 data tables

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Measurements at 0-degrees of negatively charged particles and anti-nuclei produced in collision of 14.6-A/GeV/c Si on Al, Cu, and Au targets

Aoki, M. ; Beatty, J. ; Beavis, D. ; et al.
Phys.Rev.Lett. 69 (1992) 2345-2348, 1992.
Inspire Record 344921 DOI 10.17182/hepdata.19827

We report measurements of d¯, p¯, K−, and π− produced at 0° in collisions of 14.6A GeV/c Si28 on Al, Cu, and Au targets. A beam-line focusing spectrometer was used to identify particles at rigidities from -2 to -8 GV. The ratio of d¯/p¯ invariant cross sections at midrapidity (y=1.7) is (1±0.7)×10−5, larger than expected from a calculation of dd¯ direct production but smaller than predicted by a simple coalescence model. We also report limits on the production of exotic particles.

10 data tables

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Multiplicity, Momentum and Angular Characteristics of $\pi^-$ Mesons for $p$ C, $d$ C, $\alpha$ C and C C Interactions at 4.2-{GeV}/$c$ Per Nucleon

The Alma Ata-Baku-Belgrade-Bucharest-Dubna-Kishinev-Leipzig- Moscow-Prague-Samarkand-Sofiya-Tashkent-Tbilisi-Ulan Bator-Varna collaboration Agakishiev, G.N. ; Akhababian, N. ; Armutliisky, D. ; et al.
Z.Phys.C 27 (1985) 177, 1984.
Inspire Record 203342 DOI 10.17182/hepdata.1999

Light ion collisions with carbon target at 4.2 GeV/c/N are studied. Pion multiplicity distributions, momentum and angular spectra are analysed. These data are described in terms of models assuming independent interactions of nucleons from the projectile nucleus with the target.

18 data tables

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Negative pion production in subthreshold heavy ion collisions

Suzuki, T. ; Fukuda, M. ; Ichihara, T. ; et al.
Phys.Lett.B 257 (1991) 27-31, 1991.
Inspire Record 324305 DOI 10.17182/hepdata.29463

Inclusive π − spectra have been measured for 14 N+C collisions at 41 A , 67 A , 80 A and 135 A MeV, the lowest energies measured for the charged pion. The cross sections fall exponentially with T π and the exponential slope factors at 90° in the nucleon-nucleon center of mass frame are determined. Energy distributions below a beam energy of 100 A MeV are less steep than expected from the monotonic decrease of the slope factor down to 100 A MeV. The production mechanism of energetic pions far below threshold is discussed for several models.

2 data tables

No description provided.

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BEHAVIOR OF pi- MESON PRODUCTION INVARIANT DIFFERENTIAL CROSS-SECTIONS IN NUCLEAR INTERACTIONS AT 4.2-GeV/c PER NUCLEON

Armutliisky, D. ; Gasparian, A.P. ; Grishin, V.G. ; et al.
Yad.Fiz. 42 (1985) 200-204, 1985.
Inspire Record 207766 DOI 10.17182/hepdata.17537

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2 data tables

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Analysis of Behavior of $\pi^-$ Mesons and Protons Produced in Nucleus-nucleus Interactions at 4.2-{GeV}/$c$ Per Nucleon Depending on the Number of Interacting Protons

Agakishiev, G.N. ; Backovic, S. ; Boldea, V. ; et al.
Sov.J.Nucl.Phys. 45 (1987) 852, 1987.
Inspire Record 235264 DOI 10.17182/hepdata.9548

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22 data tables

FRAGT IS CHARGE BARYON WITH PATH < 4 CM.

FRAGT IS CHARGE BARYON WITH PATH < 4 CM.

FRAGT IS CHARGE BARYON WITH PATH < 4 CM.

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Observation of Baryons With High Transverse Momenta in $p$, $d$, He and C Nuclear Interactions With Tantalum Nuclei at 4.2-{GeV}/$c$

Akhababian, N. ; Baatar, Ts. ; Baldin, A.M. ; et al.
Sov.J.Nucl.Phys. 37 (1983) 559, 1983.
Inspire Record 180913 DOI 10.17182/hepdata.9923

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10 data tables

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OBSERVATION OF pi- MESON CORRELATED EMISSION IN C - Ta INTERACTIONS AT P (0) = 4.2-GEV/c PER NUCLEON

Akhababian, N. ; Angelov, N. ; Baatar, Ts. ; et al.
JINR-E1-81-470, 1981.
Inspire Record 167530 DOI 10.17182/hepdata.9979

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4 data tables

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Spectra of protons and pi- mesons in C C interactions at 4.2-GeV/c per nucleon.

Kanarek, T. ; Kladnitskaya, E.N. ; Toneeva, G.P. ; et al.
Sov.J.Nucl.Phys. 48 (1988) 1054-1057, 1988.
Inspire Record 261912 DOI 10.17182/hepdata.38883

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22 data tables

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