Date

Spin Correlation Parameter A(nn) ($\theta^*$) for $n p$ Elastic Scattering at 790-{MeV}

Nath, S. ; Glass, G. ; Hiebert, J.C. ; et al.
Phys.Rev.D 39 (1989) 3520, 1989.
Inspire Record 25429 DOI 10.17182/hepdata.23226

The spin-correlation parameter Ann for free n-p elastic scattering has been measured for the first time for incident-neutron-beam energy En=790 MeV and c.m. angles 48°≤θ*≤149°. The data are compared with the widely differing predictions of several phase-shift analyses, clearly favoring one of them. They also are compared with recently published quasifree Ann data for the more limited c.m. angular region 98°≲θ*≲122°.

1 data table

No description provided.


Precision Measurements of the Anti-proton - Proton Elastic Scattering Cross-section at 90-degrees in the Incident Momentum Range Between 3.5-{GeV}/$c$ and 5.7-{GeV}/$c$

The R704 collaboration Baglin, C. ; Baird, S. ; Bassompierre, G. ; et al.
Phys.Lett.B 225 (1989) 296-300, 1989.
Inspire Record 278760 DOI 10.17182/hepdata.29802

The high antiproton-proton luminosity obtained by using a target system consisting of a hydrogen gas-jet crossing a coasting beam of cooled antiproton circulating in one of the rings of CERN's ISR provides the possibility to measure low cross section reactions with very high precision. We present measurements of the antiproton-proton elastic cross section at 90° CM at incident momenta between 3.5 GeV/ c and 5.7 GeV/ c . The precision of these measurements is much higher than previously reported results. The data show that the cross section of this reaction decreases faster than s −12 over this momentum range.

2 data tables

No description provided.

No description provided.


Production of $\Lambda$ Hyperons and $K^0(s$) Mesons in Annihilation of Anti-protons in $^{4}$He Nuclei at 600-{MeV}/$c$

Batusov, Yu.A. ; Bunyatov, S.A. ; Falomkin, I.V. ; et al.
Sov.J.Nucl.Phys. 50 (1989) 945-948, 1989.
Inspire Record 280132 DOI 10.17182/hepdata.39439

None

4 data tables

43 EVENTS WITH LAMBDA, 54 EVENTS WITH KS.

43 EVENTS WITH LAMBDA, 54 EVENTS WITH KS.

43 EVENTS WITH LAMBDA, 54 EVENTS WITH KS. D(N)/D(P) WAS FITTED BY P**2*EXP(-SLOPE*EKIN).

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EXCLUSIVE PRODUCTION OF p anti-p pi+ pi- IN PHOTON-PHOTON COLLISIONS

The TPC/Two Gamma collaboration Aihara, H. ; Alston-Garnjost, M. ; Avery, R.E. ; et al.
Phys.Rev.D 40 (1989) 2772, 1989.
Inspire Record 279349 DOI 10.17182/hepdata.23017

We report a measurement of the e+e−→e+e−pp¯π+π− process with the TPC/Two-Gamma facility at the PEP e+e− storage ring at SLAC. Forty-five pp¯π+π− events were identified in data corresponding to an integrated e+e− luminosity of 142 pb−1. The cross section for γγ→pp¯π+π− is given both as a function of the γγ center-of-mass energy Wγγ, with Wγγ between 2.5 and 5.5 GeV, and as a function of the in variant mass squared q2 of one of the photons, with −q2<7 GeV2. This cross section falls much less rapidly with Wγγ than does the cross section for a similar process, γγ→pp¯. No Δ0Δ¯0 production is observed, and only a small fraction of the events at low Wγγ is consistent with γγ→Δ++Δ¯−−, Δ++p¯π−, or Δ¯−−pπ+. In an expanded search through the same data, four events compatible with either ΛΛ¯(Λ→pπ−) or Σ0Λ¯(Σ0→Λγ) production were found.

2 data tables

Statistical errors only.

Data read from graph.


A STUDY OF FOUR AND SIX BODY REACTIONS IN K+ p AND pi+ p INTERACTIONS AT 250-GeV/c

The EHS/NA22 collaboration Ajinenko, I.V. ; Belokopytov, Yu. A. ; Bialkowska, H. ; et al.
Z.Phys.C 43 (1989) 15, 1989.
Inspire Record 279065 DOI 10.17182/hepdata.15471

Data on the reactions (K+/π+)p→(K+/π+)pπ+π- and (K+/π+)p→(K+/π+)p2π+2π-, obtained with the European Hybrid Spectrometer, are presented and compared with data at lower energies. The contribution of beam and target diffractive dissociation and double Pomeron exchange, and porperties of these reactions are discussed.

7 data tables

No description provided.

No description provided.

No description provided.

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Multiplicity of Charged Particles in Interactions of Oxygen Nuclei With Hydrogen at 3.1-{GeV}/$c$ Momentum

The Alma Ata-Warsaw-Dubna-Tashkent-Tbilisi collaboration Glagolev, V.V. ; Lebedev, R.M. ; Pestova, G.D. ; et al.
Z.Phys.A 345 (1993) 413-424, 1993.
Inspire Record 281736 DOI 10.17182/hepdata.16558

Experimental data on multiplicities of secondary charged particles in interactions of oxygen nuclei in a hydrogen bubble chamber at the incident momentum of 3.1 A GeV/c are presented and discussed. Multiplicity correlations are studied in details and it is shown that the character of these correlations is strongly influenced by the electric charge and baryon number conservation. Topologies and probabilities of different channels of fragmentation are determined for projectile oxygen nuclei. It is established that channels with production of helium nuclei play an important role in the processes of multifragment break-up of oxygen nuclei. Comparison of the experimental data with predictions of the cascadefragmentation-evaporation model has shown that the model provide the qualitative description of the considerable amount of experimental observations.

3 data tables

FRAGB-fragments of a primary nucleus with Z=2, 3, 4, 5, 6, 7, 8.

No description provided.

Events of the total disintegration of the projectile nucleus: fragments with Z=2, 3, 4, 5, 6, 7, 8 are absent.


Dijet Angular Distributions from anti-p p Collisions at s**(1/2) = 1.8-TeV

The CDF collaboration Abe, F. ; Amidei, D. ; Apollinari, G. ; et al.
Phys.Rev.Lett. 62 (1989) 3020-3023, 1989.
Inspire Record 278394 DOI 10.17182/hepdata.20046

We have measured dijet angular distributions at √s =1.8 TeV with the Collider Detector at Fermilab and the Tevatron p¯p Collider and find agreement with leading-order QCD. By comparing the distribution for the highest dijet invariant masses with the prediction of a model of quark compositeness, we set a lower limit on the associated scale parameter Λc at 330 GeV (95% C.L.).

1 data table

Numerical values read from figure in preprint.


Studies of Jet Production Rates in $e^+ e^-$ Annihilation at $e$({CM}) = 29-{GeV}

Bethke, S. ; Abrams, G. ; Adolphsen, C.E. ; et al.
Z.Phys.C 43 (1989) 325, 1989.
Inspire Record 277772 DOI 10.17182/hepdata.15472

Production rates of multijet hadronic final states are studied ine+e− annihilation at 29 GeV center of mass energy. QCD shower model calculations with exact first order matrix element weighting at the first gluon vertex are capable of reproducing the observed multijet event rates over a large range of jet pair masses. The method used to reconstruct jets is well suited for directly comparing experimental jet rates with parton rates calculated in perturbative QCD. Evidence for the energy dependene of αs is obtained by comparing the observed production rates of 3-jet events with results of similar studies performed at higher center of mass energies.

2 data tables

Observed production rates relative to the total hadronic cross section.

Production rates corrected for fragmentation, initial state radiation and detector effects.


Comparison of Inclusive Fractional Momentum Distributions of Quark and Gluon Jets Produced in $e^+ e^-$ Annihilation

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 45 (1989) 1, 1989.
Inspire Record 277210 DOI 10.17182/hepdata.15299

Inclusive charged particle production ine+e− annihilation into hadrons is studied in terms of the particle fractional momentumxp. Thexp distribution for gluon jets is extracted by comparing two data samples measured in the TASSO detector: nearly symmetric three jet events at centre-of-mass energyW∼35 GeV and two jet events atW∼22 GeV, yielding quark and gluon jets of similar energies (∼11.5 GeV). No significant difference is observed between quark and gluon jets. Monte Carlo models based on parton showers describe the trend and energy variation of the data better than a model with second order matrix element in αs.

3 data tables

2 JET data at sqrt(s) = 35 GeV.

3 JET data at sqrt(s) = 22 GeV.

Gluon jet data at sqrt(s) = 11.5 GeV.


Charged Multiplicity Distributions and Correlations in e+ e- Annihilation at PETRA Energies

The TASSO collaboration Braunschweig, W. ; Gerhards, R. ; Kirschfink, F.J. ; et al.
Z.Phys.C 45 (1989) 193, 1989.
Inspire Record 277658 DOI 10.17182/hepdata.1499

We report on an analysis of the multiplicity distributions of charged particles produced ine+e− annihilation into hadrons at c.m. energies between 14 and 46.8 GeV. The charged multiplicity distributions of the whole event and single hemisphere deviate significantly from the Poisson distribution but follow approximate KNO scaling. We have also studied the multiplicity distributions in various rapidity intervals and found that they can be well described by the negative binomial distribution only for small central intervals. We have also analysed forward-backward multiplicity correlations for different energies and selections of particle charge and shown that they can be understood in terms of the fragmentation properties of the different quark flavours and by the production and decay of resonances. These correlations are well reproduced by the Lund string model.

29 data tables

RATIO of MULT/DISPERSION for the whole event to that for the single hemisphere data.

Complete event multiplicities.

Single hemisphere multiplicities.

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