HEPData Search

Emission of light fragments at small angles is studied in relativistic heavy ion collisions using the Diogene plastic wall for both symmetrical and non-symmetrical target-projectile systems with 400 MeV per nucleon and 800 MeV per nucleon incident neon nuclei. Efficiency of multiplicity measurements in the small angle range for the selection of central or peripheral collisions is confirmed for asymmetric systems. Differential production cross sections of Z = 1 fragments show evidence for the existence of two emitting sources. The apparent temperature of each source is obtained from comparison with a thermodynamical model.

2 data tables

Table 1

THE NUCLEUS IS NAF. CHARGED PARTICLES IN THE CENTRAL DRIFT CHAMBER OF THE DIOGENE DETECTOR.

Table 2

THE NUCLEUS IS NAF. CHARGED PARTICLES IN THE CENTRAL DRIFT CHAMBER OF THE DIOGENE DETECTOR. THE EVENT SELECTION:A HEAVY FRAGMENT(Z>=6) IS REGISTRED IN THE PLASTIC WALL OF THE DIOGENE.

$\Sigma(c$)++ and $\Sigma(c$)0 Production From $e^+ e^-$ Annihilation in the $\Upsilon$ Energy Region

The CLEO collaboration Bowcock, T.J.V. ; Kinoshita, K. ; Pipkin, F.M. ; et al.

Phys.Rev.Lett. 62 (1989) 1240, 1989.

Inspire Record 25467 DOI 10.17182/hepdata.47269

We have observed Σc++ and Σc0 baryons in nonresonant e+e− interactions through their decays to Λc+π± using the CLEO detector. The mass difference M(Σc++)-M(Λc+) is measured to be 167.8±0.4±0.3 MeV; for M(Σc0)-M(Λc+) we find 167.9±0.5±0.3 MeV. Σc decay accounts for (18±3±5)% of Λc+ production.

2 data tables

Table 1

The cross section ratio is multiplied by a factor of 1.5 to account for theunobserved SIGMA/C(2455)+.

Table 2

No description provided.

PRODUCTION OF BACKWARD PROTONS WITH MOMENTA 0.2-GeV/c TO 0.5-GeV/c IN LAB SYSTEM WHICH ARE GENERATED IN pi- A INTERACTIONS AT 40-GeV/c

The RISK collaboration Bannikov, A.V. ; Bohm, J. ; Vertogradov, L.S. ; et al.

JINR-P1-89-308, 1989.

Inspire Record 281737 DOI 10.17182/hepdata.38756

None

8 data tables

Table 1

No description provided.

Table 2

THE EVENTS WITH BACKWARD PROTONS.

Table 3

THE EVENTS WITHOUT BACKWARD PROTONS.

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rivet Analysis
Observation of $\Delta^{++}$ (1232) Production in $e^+ e^-$ Annihilations Around 10-{GeV}

The ARGUS collaboration Albrecht, H. ; Glaser, R. ; Harder, G. ; et al.

Phys.Lett.B 230 (1989) 169-174, 1989.

Inspire Record 278932 DOI 10.17182/hepdata.29767

We report on the first observation of Δ(1232) ++ and Δ(1232)++¯ baryons in e + e − annihilation at energies around 10 GeV, using the ARGUS detector at DORIS II. The sum of the rates of Δ ++ and Δ++¯ per hadronic event in the continuum is measured to be 0.040±0.008±0.006, and the rate in direct ϒ(1S) decays is 0.124±0.016±0.015. The momentum spectrum of Δ ++ baryons in direct ϒ(1S) decays has been measured.

2 data tables

Table 1

Production on the UPSI(1S) resonance.

Table 2

No description provided.

Observation of Centrally Produced $\theta$ / F2 (1720) in the Reaction $p p \to p$(f) ($K \bar{K}$) $p(s$) at 300-{GeV}/$c$

The WA76 collaboration Armstrong, T.A. ; Benayoun, Maurice ; Beusch, W. ; et al.

Phys.Lett.B 227 (1989) 186-190, 1989.

Inspire Record 279351 DOI 10.17182/hepdata.29801

The K + K − and K S 0 K S 0 systems centrally produced in the reaction pp→p f K K p s have been studied at 300 GeV/ c incident momentum. Both the K + K − and the K S 0 K S 0 mass spectra show large resonant production. For the first time in hadron collisions, clear evidence is found for the θ f 2 (1720) with parameters m =1713±10 MeV, Γ =181±30 MeV for the K + K − decay mode and m =1706±10 MeV, Γ =104±30 MeV for the K S 0 K S 0 decay mode. A spin analysis of the K + K − spectrum shows that for the θ f 2 (1720) J P =2 + is strongly favoured while 0 + and 1 − are excluded.

2 data tables

Table 1

Density matrix elements contributing in the fits of angular distributions in the F2PRIME(1525) region.

Table 2

Density matrix elements contributing in the fits of angular distributions in the F2(1720) region.

The Spin Correlation Parameter and Analyzing Power in $n p$ Elastic Scattering at Intermediate-energies

Abegg, R. ; Ahmad, M. ; Bandyopadhyay, D. ; et al.

Phys.Rev.C 40 (1989) 2684-2696, 1989.

Inspire Record 281880 DOI 10.17182/hepdata.26220

In order to improve existing I=0 phase shift solutions, the spin correlation parameter ANN and the analyzing powers A0N and AN0 have been measured in n-p elastic scattering over an angular range of 50°–150° (c.m.) at three neutron energies (220, 325, and 425 MeV) to an absolute accuracy of ±0.03. The data have a profound effect on various phase parameters, particularly the P11, D23, and ε1 phase parameters which in some cases change by almost a degree. With the exception of the highest energy, the data support the predictions of the latest version of the Bonn potential. Also, the analyzing power data (A0N and AN0) measured at 477 MeV in a different experiment over a limited angular range [60°–80° (c.m.)] are reported here.

10 data tables

Table 1

The beam analysing power at incident kinetic energy 220 MeV. Additional systematic uncertainty of +- 0.015 and a scalar error of 3.5 PCT.

Table 2

The beam analysing power at incident kinetic energy 325 MeV. Additional systematic uncertainty of +- 0.018 and a scalar error of 3.1 PCT.

Table 3

The beam analysing power at incident kinetic energy 425 MeV. Additional systematic uncertainty of +- 0.022 and a scalar error of 3.3 PCT.

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Saturation of the thermal energy deposited in Au and Th nuclei by Ar projectiles between 27 and 77 MeV/u

Jiang, D.X. ; Doubre, H. ; Galin, J. ; et al.

Nucl.Phys.A 503 (1989) 560-574, 1989.

Inspire Record 25834 DOI 10.17182/hepdata.36893

Multiplicities of neutrons and light charged particles associated with central collisions have been measured in the energy range 27–77 MeV/u for the systems 40 Ar+ 197 Au, 232 Th. The experiments demonstrate the occurrence of a saturation of the thermal energy deposited in the system around 650 MeV, corresponding to a constant internal temperature close to 5 MeV.

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Threshold Measurement of the Reaction $\bar{p} p \to \bar{\ell}$ambda $\lambda$ at {LEAR}

Barnes, P.D. ; Besold, R. ; Birien, P. ; et al.

Phys.Lett.B 229 (1989) 432-438, 1989.

Inspire Record 280159 DOI 10.17182/hepdata.29780

The excitation function of the reaction p p→ Λ Λ in the threshold region has been measured at LEAR. Sixteen measurements of the total cross section, in the energy range between 0.85 MeV below threshold and 4.05 MeV above, are presented. The shapes of the measured differential cross sections indicate a remarkably strong p-wave contribution even down to the reaction threshold. We also report here the measurement of significant polarizations in the threshold region; these are compared with previous higher-energy data.

3 data tables

Table 1

Data to be supplied by authors.

Table 2

No description provided.

Table 3

No description provided.

A Measurement of the Charmed Quark Asymmetry in $e^+ e^-$ Annihilation

The JADE collaboration Ould-Saada, F. ; Allison, J. ; Ambrus, K. ; et al.

Z.Phys.C 44 (1989) 567, 1989.

Inspire Record 278937 DOI 10.17182/hepdata.15357

The charmed quark charge asymmetry has been measured at the average centre of mass energy of 35 GeV with the JADE detector at thee+e− storage ring PETRA. Charmed quarks were identified byD*± tagging using the ΔM technique.D*± mesons were reconstructed through their decay intoD0 mesons resulting in (Kπ) π and (K π π π) π final states. The measured charge asymmetryA=−0.149±0.067 is in agreement with the expectation from the electroweak interference effect in quantum flavour dynamics (QFD).

1 data table

Table 1

CHARMED quark charge asymmetry.

Date

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Reactions

Observables

CM Energies (GeV)

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Study of rho0 and f2 meson production in pi- p interactions at 360-GeV/c

EXCLUSIVE MEASUREMENTS OF LIGHT FRAGMENT PRODUCTION AT FORWARD ANGLES IN Ne - Pb AND Ne - NaF COLLISIONS AT E/A = 400-MeV AND 800-MeV

$\Sigma(c$)++ and $\Sigma(c$)0 Production From $e^+ e^-$ Annihilation in the $\Upsilon$ Energy Region

PRODUCTION OF BACKWARD PROTONS WITH MOMENTA 0.2-GeV/c TO 0.5-GeV/c IN LAB SYSTEM WHICH ARE GENERATED IN pi- A INTERACTIONS AT 40-GeV/c

rivet Analysis
Observation of $\Delta^{++}$ (1232) Production in $e^+ e^-$ Annihilations Around 10-{GeV}

Observation of Centrally Produced $\theta$ / F2 (1720) in the Reaction $p p \to p$(f) ($K \bar{K}$) $p(s$) at 300-{GeV}/$c$

The Spin Correlation Parameter and Analyzing Power in $n p$ Elastic Scattering at Intermediate-energies

Saturation of the thermal energy deposited in Au and Th nuclei by Ar projectiles between 27 and 77 MeV/u

Threshold Measurement of the Reaction $\bar{p} p \to \bar{\ell}$ambda $\lambda$ at {LEAR}

A Measurement of the Charmed Quark Asymmetry in $e^+ e^-$ Annihilation