Date

$\tau$ Production and Decay With the Cello Detector at {PETRA}

The CELLO collaboration Behrend, H.J. ; Criegee, L. ; Dainton, J.B. ; et al.
Phys.Lett.B 222 (1989) 163-172, 1989.
Inspire Record 276859 DOI 10.17182/hepdata.29824

The reaction e + e − → τ + τ − has been studied at centre of mass energies between 14.0 and 46.8 GeV with the CELLO detector at the PETRA e + e − collider. We present results for the cross section σ τ and the charge asymmetry A τ . The results are in good agreement with the standard model. We have also measured the topological decay rates BR 1 , BR 3 and BR 5 for the inclusive decay of the τ lepton into one, three and five charge particles. The results confirm and improve earlier CELLO measurements at other energies. We find for the combined values at all energies BR 1 = (84.9 ± 0.4 ± 0.3)%, BR 3 = (15.0 ± 0.4 ± 0.3)% and BR 5 = (0.16 ± 0.13 ± 0.04)%.

3 data tables

No description provided.

No description provided.

Corrected for radiative effects and background contributions.


A Measurement of Cross-sections for $^{32}$S Interactions With Al, Fe, Cu, Ag and Pb at 200-{GeV}/$c$ Per Nucleon

The NA36 collaboration Andersen, E. ; Barnes, P.D. ; Blaes, R. ; et al.
Phys.Lett.B 220 (1989) 328-332, 1989.
Inspire Record 277260 DOI 10.17182/hepdata.29840

Cross sections for charge changing and particle production are measured for 32 S collisions with Al, Fe, Cu, Ag and Pb targets at 200 GeV/ c . The measured difference between the two cross sections is discussed. Results are compared with data obtained with an 16 O beam.

2 data tables

Charge changing cross section.

Production cross section.


Atomic Weight Dependence of the Production of Hadron Pairs from 800-GeV/c Protons on Nuclear Targets

Turner, Kathleen R. ; Boca, G. ; Georgiopoulos, C. ; et al.
Phys.Rev.Lett. 66 (1991) 864-867, 1991.
Inspire Record 278395 DOI 10.17182/hepdata.19892

Fermilab experiment 711 has investigated proton-nucleus collisions in which two high-transverse-momentum hadrons are produced forming high-mass ++, +-, and -- charged states, using an 800-GeV/c proton beam on targets of beryllium, aluminum, iron, and tungsten. Our data cover the range in dihadron mass from 6 to 15 GeV/c2. We show here that the dependence of the cross section on atomic weight A can be parametrized as Aα where α=1.043±0.011(stat)±0.025 (syst), and is independent of the charge state of the dihadron system.

3 data tables

No description provided.

No description provided.

No description provided.


$\Lambda$(c)+ Production and Semileptonic Decay in 29-{GeV} $e^+ e^-$ Annihilation

Klein, S. ; Himel, T. ; Abrams, G.S. ; et al.
Phys.Rev.Lett. 62 (1989) 2444, 1989.
Inspire Record 277034 DOI 10.17182/hepdata.20042

We present results on Λc+ production in 29-GeV e+e− annihilation. The Λc+ are observed via their semileptonic decays to Λe+X and Λμ+X. With radiative corrections, we find σ(e+e−→Λc+X)〉BΛc+→eΛX)= 1.5±0.6±0.5 pb or 0.0038±0.0015±0.0012 Λc+→Λe+X decay per hadronic event, and σ(e+e−Λc+X)B(Λc+→μΛX)= 1.4±1.4±0.4 pb or 0.0035±0.0035±0.0011 Λc+→Λμ+X decay per hadronic event. These results can be used to place constraints on the predictions of various production models.

2 data tables

Cross sections * branching ratio for LAMBDA/C+ production in LAMBDA E+ decay channel.

Cross sections * branching ratio for LAMBDA/C+ production in LAMBDA MU+ decay channel.


Observation of Double $\phi$ Meson Production in the Central Region for the Reaction $p p \to p$(f) ($K^+ K^- K^+ K^-$) $p(s$) at 300-{GeV}/$c$

The WA76 collaboration Armstrong, T.A. ; Benayoun, Maurice ; Beusch, W. ; et al.
Phys.Lett.B 221 (1989) 221-226, 1989.
Inspire Record 276743 DOI 10.17182/hepdata.29825

The reaction pp→p f (K + K − K + K − )p s in which the K + K − K + K − system is centrally produced has been studied at 300 GeV/ c . φφ production has been observed and the ratio σ (φK + K − )/ σ ( φφ ) is 1.0±0.3. The cross section for central production of φφ is found to be the same at 300 GeV/ c and 85 GeV/ c . An angular analysis of the φφ system favours J P =2 + over 0 − .

1 data table

No description provided.


A Spin Parity Analysis of the F(1) (1285) and F(1) (1420) Mesons Centrally Produced in the Reaction $p p \to p$(f) ($K^0_S K^\pm \pi^\mp$) at $p(s$) at 300-{GeV}/$c$

The WA76 collaboration Armstrong, T.A. ; Benayoun, Maurice ; Beusch, W. ; et al.
Phys.Lett.B 221 (1989) 216-220, 1989.
Inspire Record 276742 DOI 10.17182/hepdata.29828

Results are presented of an analysis of the reaction pp→p f (K S 0 K ± π ∓ )p s at 300 GeV/ c . Clear f 1 (1285) and f 1 (1420) signals are seen. A spin-parity analysis shows that both are consistent with being 1 ++ states. The f 1 (1420) is found to decay only to K ∗ K and no 0 −+ or 1 +− waves are required to describe the data. The production of the f 1 (1285) as a function of energy is not the same as that for the f 1 (1420) whose cross section is found to be constant with energy.

1 data table

No description provided.


Properties of Binary Fission and Multifragmentation in the Transition Regime

Klotz-Engmann, G. ; Oschler, H. ; Stroth, J. ; et al.
Nucl.Phys.A 499 (1989) 392-412, 1989.
Inspire Record 285129 DOI 10.17182/hepdata.36939

Correlations between target fragments were measured in α- and 14 N-induced reactions at 70, 250 and 800 MeV/u incident energies. The reaction mechanism is characterized by the linear momentum transfer and the excitation energy which were deduced from the kinematics and the mass distribution of the fission fragments. By selecting targets lighter than Th (Au and Ho) the yield from peripheral collisions is reduced by the increase in the fission barrier thus allowing events with the highest linear momentum transfer and excitation energy to be favoured. The results show that up to an incident energy of 800 MeV/u hot nuclei are formed which decay via normal binary fission. The linear momentum transfer is essentially constant over the covered energy range, but the excitation energy increases until the total incident energy is greater than 3 GeV. At this energy, independent of the projectile mass the fission probability of the heavy nuclei drops below 50%, while the emission of intermediate-mass fragments increases. The relative velocities between two intermediate-mass fragments exceed strongly the values of binary fission. Monte Carlo calculations show that the relative velocities between these fragments exclude a sequential emission from the recoil nucleus and support a simultaneous breakup mechanism.

5 data tables

SIG IS FISSION CROSS-SECTION CALCULATED WITH THE SOFT-SPHERE MODEL OF REF. PHYS.REV.C11 (1975) 1203.

SIG IS FISSION CROSS-SECTION CALCULATED WITH THE SOFT-SPHERE MODEL OF REF. PHYS.REV.C11 (1975) 1203.

SIG IS FISSION CROSS-SECTION CALCULATED WITH THE SOFT-SPHERE MODEL OF REF. PHYS.REV.C11 (1975) 1203.

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RESONANCE PATTERN OF LOW MASS MUON PAIRS PRODUCED IN 38-GEV/C PI- C INTERACTIONS.

The RISK collaboration Bannikov, A.V. ; Bohm, J. ; Choe, Song Hek ; et al.
DUBNA JINR - 89-486 (89,REC.OCT.) 14p, 1989.
Inspire Record 286947 DOI 10.17182/hepdata.39438

None

3 data tables

No description provided.

No description provided.

No description provided.


Study of the $\pi^+ \pi^+ \pi^- \pi^-$ System Centrally Produced by Incident $\pi^+$ and $p$ Beams at 85-{GeV}/$c$

The WA76 collaboration Armstrong, T.A. ; Bloodworth, I.J. ; Carney, J.N. ; et al.
Z.Phys.C 43 (1989) 55, 1989.
Inspire Record 276888 DOI 10.17182/hepdata.15434

The reactions π+p→π+(π+π+π-π-)p andpp→p(π+π+π-π-)p, where the (π+ π+ π- π-) system is centrally produced have been studied at 85 GeV/c. The π+π+π-π- mass spectrum shows evidence for thef1 (1285) meson with a mass of 1278±2 MeV and width 41±12 MeV which decays mainly through ρ0(770)π+π-. Thef1(1285) is also observed in the ηπ+π- channel. There is no significant evidence for ηππ or 4π decay modes of thef1(1420). The ρ0ρ0 production is found to be small. A Dalitz plot analysis of the 3π system shows evidence fora2 (1320) production and for a large contribution of theJPC=1++ ρπ wave.

3 data tables

No description provided.

No description provided.

No description provided.


K0(S) PRODUCTION IN ANTI-P P INTERACTIONS AT S**(1/2) = 630-GeV AND 1800-GEV

The CDF collaboration Abe, F. ; Amidei, D. ; Apollinari, G. ; et al.
Phys.Rev.D 40 (1989) 3791-3794, 1989.
Inspire Record 287811 DOI 10.17182/hepdata.22999

Measurements of inclusive transverse-momentum spectra for KS0 mesons produced in proton-antiproton collisions at s of 630 and 1800 GeV are presented and compared with data taken at lower energies. The ratio, as a function of pT, of the cross section for KS0 to that for charged hadrons is very similar to what is observed at lower energies. At 1800 GeV, we calculate the strangeness-suppression factor λ=0.40±0.05.

4 data tables

Estimated effective cross sections for events which pass the trigger and selection criteria. The uncertainties in these represent the principal source of error in the overall normalisation of the results.

Statistical errors only.

Statistical errors only.

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