ANTI-NEUTRINO - NUCLEON TOTAL CROSS-SECTION AND RATIO OF ANTI-NEUTRINO CROSS-SECTION ON NEUTRONS AND PROTONS

Erriquez, O. ; Fogli-Muciaccia, M.T. ; Natali, S. ; et al.
Phys.Lett.B 80 (1979) 309-313, 1979.
Inspire Record 143176 DOI 10.17182/hepdata.27366

On a selected sample of 2171 events, observed in the big heavy liquid bubble chamber Gargamelle at CERN, the charged current total cross section for antineutrino on nucleons has been determined up to the laboratory energy E v ̄ = 8 GeV . The total cross section is found to be a linear function of the antineutrino energy expressed by σ tot (E v ̄ ) = (0.26 ± 0.020) × 10 −38 × E v ̄ ( GeV ) cm 2 . The energy dependence of 〈q 2 〉 v ̄ is found to be given by 〈q 2 〉 v ̄ = (0.15 ± 0.04)E v ̄ + (0.05 ± 0.12) ( GeV /c) 2 . With a simplified nuclear model the ratio of cross sections on neutrons andprotons has been estimated as a function of energy and for two different values of the scaling variable x . The results are compared with the prediction of the naive quark parton model.

1 data table

Measured charged current total cross section.


P P ---> D PI+ REACTION AT 0.8-GEV

Nann, H. ; Iversen, S. ; Kaletka, M. ; et al.
Phys.Lett.B 88 (1979) 257-261, 1979.
Inspire Record 147794 DOI 10.17182/hepdata.27297

Differential cross sections and polarization asymmetries for the reaction p + p → d + π + have been measured at 0.8 GeV. The data has been analyzed within the formalism of Mandl and Regge and the results are compared with the recent coupled channel calculations of Niskanen. It is concluded that at this energy the production of upto f-wave pions is important.

2 data tables

No description provided.

No description provided.


COMPARISON OF DIRECT PHOTON PRODUCTION IN P P COLLISIONS AT S**(1/2) = 30.6-GEV AND 53.2-GEV

Amaldi, E. ; Beneventano, M. ; Borgia, B. ; et al.
Phys.Lett.B 84 (1979) 360-362, 1979.
Inspire Record 146580 DOI 10.17182/hepdata.27321

We present data obtained at the ISR, on the determination of the ratio R = γ π 0 at s = 30.6 GeV and we compare the results with our previous measurement at s = 53.2 GeV. The ratio R = γ π 0 integrated over the interval 0.1 ⩽ χ T ⩽ 0.2 is (1.6 ± 0.5) × 10 −2 and we obtain an indication of a universal χ T dependence.

1 data table

No description provided.


Coherent $K$(s) Regeneration on Protons From 30-{GeV}/$c$ to 130-{GeV}/$c$

Bock, G.J. ; Aronson, S.H. ; Freudenreich, K. ; et al.
Phys.Rev.Lett. 42 (1979) 350, 1979.
Inspire Record 7461 DOI 10.17182/hepdata.20779

Precise measurements att=0 of the KLp→KSp amplitude (modulus and phase) were made. Over 50000 Kπ2 decays along with normalizing Kμ3 events were detected behind a 7.2-m-long liquid-hydrogen regenerator. The momentum dependence of the modulus and phase are presented, and the results are combined with those of other experiments to extract the relevant parameters of ω exchange.

2 data tables

RESULTS USING ETA+- = 2.15E-3.

RESULTS USING ETA+- = 2.27E-3.


MEASUREMENT OF TWO AND THREE SPIN PARAMETERS AT 6-GEV/C USING A TRANSVERSELY POLARIZED BEAM AND TARGET

Beretvas, A. ; Miller, D. ; Auer, I.P. ; et al.
Phys.Rev.D 20 (1979) 21-32, 1979.
Inspire Record 146770 DOI 10.17182/hepdata.24227

Toward the goal of experimentally determining pp elastic scattering amplitudes at 6 GeV/c, we have measured a linear combination of triple-spin correlation parameters and also a linear combination of spintransfer parameters over the |t| range between 0.2 and 1.0 (GeV/c)2. A horizontally polarized beam (S direction) was obtained by precessing the spin of the polarized beam from the Argonne Zero Gradient Synchrotron using a superconducting solenoid. The target protons were polarized vertically (N direction) and the polarization of the recoil protons was measured with a carbon polarimeter. The results are consistent with the amplitude corresponding to π exchange being almost real and positive.

1 data table

KSS = (S00S) AND HSNS = (SN0S) MEASURED HERE CONTAIN SMALL ADMIXTURES OF THE OTHER SPIN-TRANSFER AND TRIPLE-SPIN CORRELATION PARAMETERS RESPECTIVELY DUE TO THE POLARIZED TARGET MAGNETIC FIELD - SEE TEXT. MEAN VALUE OF HSNS OVER THIS T-RANGE IS 0.098 +- 0.085. PARITY CONSERVATION REQUIRES THE VANISHING OF THE PARAMETERS KSN, HSNN, (000S) AND DNS, WHILE (000N) MUST AGREE WITH THE SINGLE SCATTERING POLARIZATION PARAMETER (0N00).


STUDY OF INCLUSIVE REACTIONS K- P ---> ANTI-K0 X AND K- P ---> LAMBDA0 X AT 6.5-GeV/c

De Clercq, C. ; Johnson, D.P. ; Lemonne, J. ; et al.
Phys.Rev.D 19 (1979) 3197-3209, 1979.
Inspire Record 146772 DOI 10.17182/hepdata.24272

Inclusive V0 production in 6.5-GeV/c K−p interactions is studied using the ANL 12-ft-diameter hydrogen bubble chamber. The total cross sections for inclusive K¯0 and Λ0 production are σ(K¯0)=7.98±0.49 mb and σ(Λ0)=3.94±0.24 mb. Semi-inclusive differential cross sections are determined as functions of Feynman x and transverse momentum squared of the V0's and of four-momentum transfer to the V0. The average charge multiplicity, the ratio 〈nc〉D, and the correlation function f2cc for the neutrally charged hadronic system recoiling from the V0 are determined as functions of the mass of the recoiling system. Results are used to examine universal aspects of multiparticle production.

4 data tables

No description provided.

No description provided.

No description provided.

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Cross-section of the Reaction $e^+ e^- \to \pi^+ \pi^- \pi^0$ for Center-of-mass Energies From 750-{MeV} to 1100-{MeV}

Cordier, A. ; Delcourt, B. ; Eschstruth, P. ; et al.
Nucl.Phys.B 172 (1980) 13-24, 1980.
Inspire Record 140174 DOI 10.17182/hepdata.34511

We present the results obtained with the magnetic detector DM1 at the Orsay storage ring ACO for the reaction e + e − → π + π − π 0 from 483 to 1100 MeV in the center of mass. Our data show without ambiguity an interference effect between the ω and φ mesons, which corresponds to a negative coupling constant product ratio Re( g γω g ω →3 π / g γφ g φ →3 π ) ; however our measurements above the φ, performed using kinematical analysis, can only be explained by a higher energy contribution. In addition, the parameters of the ω have been obtained with an improved accuracy compared to other experiments, and particularly the branching ratio B ω →e + e − = (6.75±0.69) × 10 −5 . We confirm that the reaction e + e − → π + π − π 0 proceeds essentially via a quasi-two-body state ϱπ , at the energy of the φ.

1 data table

FITTED CROSS SECTION AT OMEGA PEAK IS 1410 +- 130 NB AND AT PHI PEAK IS 615 +- 55 NB.


DIFFERENTIAL CROSS-SECTIONS FOR RADIATIVE CAPTURE OF PIONS ON HYDROGEN IN THE DELTA (1232) REGION: A TEST OF THE ISOSPIN STRUCTURE AND T SYMMETRY OF HADRONIC ELECTROMAGNETIC INTERACTIONS

Tran, M.T. ; Guex, L.H. ; Alder, J.C. ; et al.
Nucl.Phys.A 324 (1979) 301-334, 1979.
Inspire Record 147550 DOI 10.17182/hepdata.37080

Radiation capture of π − on hydrogen has been measured in the momentum range from p π − = 210 MeV/ c to p π − = 385 MeV/ c and for c.m. angles between 30° and 120°, covering the Δ (1232) resonance. The unambiguous separation of the events from the charge exchange background is based on precise neutron time-of-flight measurements. Detector efficiencies were carefully determined in separate experiments. The experimental results are in good agreement with those of the inverse reaction and with most recent multipole analyses. An upper limit of ±2% can be set on the contribution of the isotensor term to the transition amplitude. A time reversal violating phase, when added to the resonant M 1+ 3 amplitude in the Donnachie-Shaw model, is found to be consistent with zero.

1 data table

This results was extracted from the cross sections for the inverse reactionPI- P --> GAMMA N via detailed balance by applying relation: D(SIG(GAMMA))/D(OM EGA)=D(SIG(PI-))/D(OMEGA)*P(PI)**2/2/P(GAMMA)**2.


MULTI - HADRON PRODUCTION IN E+ E- ANNIHILATION AT 1.45-GEV - 1.61-GEV center-of-mass ENERGY

Esposito, B. ; Marini, A. ; Pallotta, M. ; et al.
Lett.Nuovo Cim. 25 (1979) 5-12, 1979.
Inspire Record 145867 DOI 10.17182/hepdata.37370

None

2 data tables

No description provided.

No description provided.


NEUTRON DISSOCIATION INTO P PI- AT 19-GEV/C

Bakken, V. ; Jacobsen, T. ; Gennow, H. ; et al.
Nuovo Cim.A 49 (1979) 465-483, 1979.
Inspire Record 145707 DOI 10.17182/hepdata.37532

The reaction pn→ppπ at 19 GeV/c is studied. It is dominated by the process where the neutron dissociates into the pπ- system and exhibits the characteristic features of diffraction dissociation. The pπ- mass distribution shows a strong peak at 1.3 GeV but is otherwise rather structureless. By comparison with other experiments we find that this peak is neither seen at higher nor at lower energies. The reason why it is not seen in experiments at higher energies seems to be that they suffer from strong experimental limitations. The 1.3 GeV peak is connected with small momentum transfers and an analysis of the moments of the decay angular distributions shows that this peak is a low-spin phenomenon. For larger momentum transfers the lowest moments show an onset already at threshold. By comparison with a pion exchange Deck model we find a substantial baryon exchange contribution for small momentum transfers. This contribution seems to become more pronounced at higher energies.

1 data table

CORRECTED FOR UNOBSERVED DECAY MODES.