Date

Measurement of e+ e- ---> e+ e- and e+ e- ---> mu+ mu- at SPEAR

Augustin, J.E. ; Boyarski, A. ; Breidenbach, Martin ; et al.
Phys.Rev.Lett. 34 (1975) 233, 1975.
Inspire Record 91755 DOI 10.17182/hepdata.21210

The reactions e+e−→e+e− and e+e−→μ+μ− have been measured at center-of-mass energies 3.0, 3.8, and 4.8 GeV and production angles of 50°<θ<130° over all azimuthal angles. Agreement with quantum electrodynamics is excellent. New limits for cutoff parameters in quantum-electrodynamic-breakdown models are given.

2 data tables

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Preliminary Result of Frascati (ADONE) on the Nature of a New 3.1-GeV Particle Produced in e+ e- Annihilation

Bacci, C. ; Celio, R.Balbini ; Berna-Rodini, M. ; et al.
Phys.Rev.Lett. 33 (1974) 1408, 1974.
Inspire Record 90991 DOI 10.17182/hepdata.21293

We report on the results at ADONE to study the properties of the newly found 3.1-BeV particle.

1 data table

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Discovery of a Narrow Resonance in $e^+ e^-$ Annihilation

The SLAC-SP-017 collaboration Augustin, J.E. ; Boyarski, A. ; Breidenbach, Martin ; et al.
Phys.Rev.Lett. 33 (1974) 1406-1408, 1974.
Inspire Record 91761 DOI 10.17182/hepdata.21247

We have observed a very sharp peak in the cross section for e+e−→hadrons, e+e−, and possibly μ+μ− at a center-of-mass energy of 3.105±0.003 GeV. The upper limit to the full width at half-maximum is 1.3 MeV.

1 data table

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Measurement of Spin Spin Correlation Parameter C(NN) in Proton Proton Scattering at 6-GeV/c

Hicks, G. ; Miller, D. ; Wilson, C. ; et al.
Phys.Rev.D 12 (1975) 2594, 1975.
Inspire Record 91591 DOI 10.17182/hepdata.24849

As part of a program to determine proton-proton elastic-scattering amplitudes, we have measured the spin-spin correlation parameter CNN at 6 GeV/c. Measurements were made over the |t| range of 0.08 to 1.4 (GeV/c)2 using a polarized beam and a polarized target at the Argonne National Laboratory Zero Gradient Synchrotron.

1 data table

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Inclusive $\Gamma, \pi^0, K^0$ and $\Lambda$ Production in 12.4-GeV/c p p Interactions

Jaeger, K. ; Campbell, J. ; Charlton, G. ; et al.
Phys.Rev.D 11 (1975) 1756, 1975.
Inspire Record 91209 DOI 10.17182/hepdata.24928

In an exposure of the Argonne National Laboratory 12-foot hydrogen bubble chamber to a beam of 12.4-GeV/c protons, we have measured the total and differential cross sections for the inclusive reactions p+p→γ+X, π0+X, K0+X, and Λ+X, as well as estimates for the inclusive η and Σ0 cross sections. We present the average number of π0, K0, and Λ as a function of the associated charge multiplicity. We observe that the average charge multiplicity in pp collisions is the same whether or not a π0, K0, or Λ is also produced in the interaction. Invariant cross sections are presented as a function of PT2 and x, the Feynman scaling variable. The π0 differential cross sections are consistent with the relation dσdP(π0)=12[dσdP(π+)+dσdP(π−)] for all pion momenta P. The differential cross section for Λ production indicates a break in the distribution of |t−tmin|=1.4 (GeV/c)2. The polarization of the Λ's is found to be consistent with zero for all values of x.

1 data table

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Study of the $\bar{p} d- \to \bar{p} pn$ and $\bar{p} n- \to \bar{p} n$ reactions at 5.55 GeV/c

Braun, Henri ; Brick, D. ; Fridman, A. ; et al.
Phys.Rev.D 10 (1974) 3573-3578, 1974.
Inspire Record 97249 DOI 10.17182/hepdata.24934

From a 150 000-photograph exposure, we analyzed the p¯d→p¯psn reaction, ps denoting a proton stopping in the deuterium-filled bubble chamber. Choosing kinematical regions in which the ps can be recognized as a spectator, we studied the p¯n→p¯n process. From the observed p¯n diffraction peak, we obtained an exponential slope for the four-momentum-transfer distribution of bn=9.4±0.8 (GeV/c)−2, the elastic p¯n cross section being estimated as σe(p¯n)=16.5±2.4 mb. The present values in conjunction with those obtained at ≈1.8 and 3.5 GeV/c show that in this region bn and σe(p¯n) decrease with increasing incident momentum. We compared our data with the reactions np→np at ≈5.4 GeV/c and p¯p→p¯p at 5.7 GeV/c. The p¯n→p¯n and np→np differential cross sections exhibit a crossover phenomenon while p¯p and p¯n elastic scattering show an isospin dependence. We also analyzed the p¯d→p¯psn reaction by means of the Glauber formalism.

2 data tables

No description provided.

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New measurement of the total cross-section in proton proton scattering in pure spin states

de Boer, W. ; Fernow, Richard C. ; Krisch, A.D. ; et al.
Phys.Rev.Lett. 34 (1975) 558-559, 1975.
Inspire Record 107097 DOI 10.17182/hepdata.3352

We have remeasured the total cross section for proton-proton scattering at 2-6 GeV/c in the spin states ↑↑ and ↑↓ perpendicular to the beam direction. With the reduced errors significant differences were found between the two cross sections.

2 data tables

DIFFERENCE OF TOTAL CROSS SECTIONS FOR ANTIPARALLEL AND PARALLEL SPINS PERPENDICULAR TO THE BEAM DIRECTION.

No description provided.


Inclusive and Semiinclusive $\rho^0$ Production in $\pi^- p$ Interactions at 147-GeV/c.

Fong, D. ; Heller, M. ; Shapiro, A.M. ; et al.
Phys.Lett.B 60 (1975) 124-128, 1975.
Inspire Record 102526 DOI 10.17182/hepdata.27734

We present data on inclusive and semi-inclusive ϱ 0 production in 147 GeV/ c π − p interactions. We find a total cross section of 7.3 ± 1.3 mb. Most of this cross section is found in the lower topology events (⩽ 10 prongs), and in the central and forward rapidity regions. The P T 2 dependence of ϱ 0 production, 〈: n > ϱ 0 per event, and the ϱ 0 / π + ratios are also discussed.

1 data table

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Study of the Reactions K- p ---> Lambda0+ in the C.M. Range from 1580 to 1750 MeV

London, G.W. ; Yu, Y.P. ; Boyd, D.P. ; et al.
Nucl.Phys.B 85 (1975) 289-310, 1975.
Inspire Record 108008 DOI 10.17182/hepdata.32121

Results on the channels K − p → Λ 0 η 0 , Λ 0 π 0 , Σ 0 π 0 , Λ 0 π 0 π 0 and Σ 0 π 0 π 0 are obtained in a K − p formation experiment using 1 million photographs taken in a heavy liquid bubble chamber filled with a CF 3 BrC 3 H 8 mixture. The results are compared with hydrogen bubble chamber (HBC) experiments and with experiments having full or partial gamma-ray detection. Our Λ 0 π 0 and Λ 0 + neutral cross section agree with HBC results. Our Σ 0 π 0 cross section does not exhibit a bump at 1670 MeV as previously seen in HBC experiments. Our Λ 0 π 0 π 0 data are dominated by a Σ (1385) π 0 production. Our Σ 0 π 0 π 0 data is consistent with the presence of some Σ (1405) π 0 production.

24 data tables

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The Reactions K+ n --> (K pi pi) 0+ n+ 0 at 2-GeV/c to 3-GeV/c

Banerjee, S. ; Campbell, J.R. ; Hall, G. ; et al.
Nucl.Phys.B 97 (1975) 413-425, 1975.
Inspire Record 103797 DOI 10.17182/hepdata.31923

The reactions K + n → K + π + π − n, K + n → K 0 π + π − p and K + n → K + π − π 0 p have b investigated in a 3.8 event/μb K + d bubble chamber experiment with incident momenta of 2.2, 2.45 and 2.7 GeV/ c . Channel cross sections are given and the general characteristics of the production processes described. The isobar model is used in an attempt to determine the spin-parity structure of the final states.

2 data tables

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