Carboni, G.
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Production of Vector and Tensor Mesons in Proton Proton Collisions at $\sqrt{s}=52$.5-{GeV}

The Annecy(LAPP)-CERN-College de France-Dortmund-Heidelberg-Warsaw collaboration Drijard, D. ; Fischer, H.G. ; Geist, Walter M. ; et al.
Z.Phys.C 9 (1981) 293, 1981.
Inspire Record 164535 DOI 10.17182/hepdata.14085

Inclusive production of ϱ0,f, andg0 mesons and ofKs0,K*0 (892), ϕ andK*0(1430)mesons has been measured at ∼2.6 and ∼1.1 GeV/c in proton-proton interactions at\(\sqrt s= 52.5\) GeV. The negative particle from the two-body decays of these resonances were identified by a threshold Cerenkov counter and used for triggering. Starting from the measured differential cross section, total inclusive cross sections for the vector and tensor mesons were determined using various parametrizations for they andpT dependence of the differential cross section. The experimental results are discussed in the framework of production models based on the parton picture. The strangeness suppresion factor λ=(0.30±0.10) due toSU(3) symmetry breaking of the quark sea is derived.

1 data table
Table 1

No description provided.


Charged Pion Production in 70-{GeV}/$c K^+ P$ Interactions

Barth, M. ; De Clercq, C. ; De Wolf, E.A. ; et al.
Z.Phys.C 7 (1981) 187-198, 1981.
Inspire Record 166694 DOI 10.17182/hepdata.14086

Inclusive charged pion production is studied in an exposure of BEBC, filled with hydrogen, to an incidentK+ beam of 70 GeV/c. Total cross sections for pion production and inclusive longitudinal and transverse momentum distributions of π−'s and of positive particles are presented and compared with data at lower energies. Earlier evidence for scaling in the fragmentation regions is confirmed. The central region π− cross section increases proportionally topLAB−1/4; positive particles show almost no energy dependence atx=0. Particle ratios π+/π− are studied as a function ofx andy* and a comparison with 70 GeV/cK−p data is made. Analysis of structure functions for (ππ) pairs and of particle production associated with π± triggers at large |x| in the context of quark/parton models, provides qualitative evidence for the diquark-quark structure of the proton.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Precise Measurement of the Xi0 Magnetic Moment

Cox, P.T. ; Dworkin, J. ; Overseth, O.E. ; et al.
Phys.Rev.Lett. 46 (1981) 877-880, 1981.
Inspire Record 169860 DOI 10.17182/hepdata.20645

The magnetic moment of the Ξ0 hyperon has been measured to be μΞ0=−1.253±0.014 nuclear magnetons. A new measurement of μΛ is also reported.

1 data table
Table 1

No description provided.


Search for Narrow Resonances in $e^+ e^-$ Annihilation at $c$.m. Energies Between 33.0-{GeV} and 36.72-{GeV}

The JADE collaboration Bartel, W. ; Cords, D. ; Dittmann, P. ; et al.
Phys.Lett.B 100 (1981) 364-366, 1981.
Inspire Record 164319 DOI 10.17182/hepdata.45224

A search for narrow resonances in e + e − annihilation between 33.00 and 36.72 GeV is reported. No evidence is found for the existence of such states. The 90% confidence upper limit on the integrated resonance cross section is determined to be 28 nb MeV, a value significantly below that expected for the lowest t t bound state.

2 data tables
Table 1

AVERAGE R VALUE THROUGHOUT ENERGY RANGE. SYSTEMATIC ERROR IS CONSERVATIVE AND WILL BE IMPROVED.

Table 2

R VALUES AT 20 MEV STEPS. DATA TAKEN FROM TABLE IN THE PREPRINT.


The Effective Energy Dependence of the Charged Particle's Multiplicity in $P / \pi^+ / K^+$ Interactions on Protons at 147 GeV/c

Brick, D. ; Rudnicka, H. ; Shapiro, A.M. ; et al.
Phys.Lett.B 103 (1981) 241-246, 1981.
Inspire Record 170358 DOI 10.17182/hepdata.6707

The energy dependence of the average of the charged multiplicity and its dispersion in π + /K + /p interaction on protons at 147 GeV/ c is found to be the same as in e + e − annihilations if an “effective energy” variable is used instead of the total energy. The effective energy S eff is defined as the invariant mass of all secondaries left after the two leading particles have been removed. Fitting the expression aS eff b to the average charge multiplicity 〈 n ch 〉, we find the power b to be in good agreement with the value of 0.25 predicted by Fermi's statistical model and by Landau's hydrodynamical model.

6 data tables
Table 1

BINS IN WEFF SELECTED SO AS TO YIELD 200 EVENTS IN EACH BIN.

Table 2

200 EVENTS IN EACH BIN IN WEFF.

Table 3

50 EVENTS IN EACH BIN IN WEFF.

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A Measurement of the Cross-Section for Four Pion Production in gamma gamma Collisions at SPEAR

Burke, D.L. ; Abrams, G.S. ; Alam, M.S. ; et al.
Phys.Lett.B 103 (1981) 153-156, 1981.
Inspire Record 165016 DOI 10.17182/hepdata.31168

We present a measurement of the cross section for the reaction e + e − → e + e − π + π − π + π − at SPEAR. This channel is found to be large and dominated by the process γγ → ϱ 0 ϱ 0 → π + π − π + π − . The cross section, which is small just above the four-pion threshold, exhibits a large enhancement near the ϱ 0 ϱ 0 threshold.

1 data table
Table 1

Axis error includes +- 0.0/0.0 contribution (THE QUOTED ERRORS INCLUDE VARIOUS SYSTEMATIC ERRORS ADDED QUADRATICALLY).


Evidence for Planar Events and a Forward Double Jet Structure in Deep Inelastic Muon Scattering

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.
Phys.Lett.B 100 (1981) 433-438, 1981.
Inspire Record 164536 DOI 10.17182/hepdata.31213

The final states of charged hadrons produced in 280 GeV μp scattering are analysed with respect to their planarity and jet structure. Distributions of p ⊥ 2 in and p ⊥ out 2 are presented. A two jet structure in the forward hemisphere is observed for events with high p ⊥ tracks are predicted by QCD models.

2 data tables
Table 1

PTIN**2 is the sum of the PTIN components squared.

Table 2

PTOUT**2 is the sum of the PTOUT components squared.


The Reaction $\gamma p \to p \pi^+ \pi^- \pi^+ \pi^-$ for Photon Energies From 25-{GeV} to 70-{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 189 (1981) 15-39, 1981.
Inspire Record 164533 DOI 10.17182/hepdata.34258

Measurements of the reaction γ p → p π + π − π + π − are presented, in which π + π − π + π − systems with masses up to 3 GeV are produced from fragmentation of the incident photon. The reaction is dominated by production of the large peak of the ϱ′(1600) meson and, at higher masses ≳2 GeV, y production of jet-like 4 π systems. The ϱ′(1600) meson is produced by a predominantly s -channel helicity conserving mechanism. At higher masses there are also indications of ϱπ peaks, of masses 1.3 GeV (the A 2 meson) and 1.75 GeV, produced with a recoiling π meson by a mechanism consistent with the Deck effect.

1 data table
Table 1

CORRECTED FOR TAILS OF BREIT-WIGNER RESONANCE USED IN FIT AND ALLOWING FOR 10 PCT BACKGROUND.


Measurement of $D^*$ Production in Pion - Nucleon Interactions at 200-{GeV}/$c$

Fitch, V.L. ; Montag, A.D. ; Sherman, S.S. ; et al.
Phys.Rev.Lett. 46 (1981) 761, 1981.
Inspire Record 10286 DOI 10.17182/hepdata.20641

Results are reported of an experiment to measure the cross section for production of the D*+ (D*−) in 200-GeV/c π−N interactions. We observe 78 ± 26 events corresponding to a D*-production cross section dσdy=1.6±0.5 μb at y=0.

1 data table
Table 1

No description provided.


Measurement of the Ratio of Total and Differential Cross-sections on Neutron and Proton for Charged Current Neutrino Events

The BEBC TST Neutrino collaboration Armenise, N. ; Calicchio, M. ; Erriquez, O. ; et al.
Phys.Lett.B 102 (1981) 374-380, 1981.
Inspire Record 164906 DOI 10.17182/hepdata.31183

Charged-current neutrino interactions have been analysed in a sample of pictures from BEBC equipped with a TST. Using a method independent of both the neutrino flux and nuclear interaction corrections, the ratio R = σ n / σ p has been measured. The result is R =1.98±0.19 for the ratio of total cross sections. Bjorken x distributions for proton and neutron targets and for u and d quarks are compared.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.