Date

Neutron Fragmentation and Inclusive Charge Exchange in p d and pi+ d Interactions at 195-GeV/c

Eisenberg, Y. ; Haber, B. ; Hochman, D. ; et al.
Phys.Rev.Lett. 38 (1977) 108, 1977.
Inspire Record 109610 DOI 10.17182/hepdata.21024

An excess of negative particles and depletion of positive particles in the backward hemisphere (c.m. system) is observed in π+ and p interactions on neutron target. dσ−dy is compared with pp interactions and the difference is related to the slow-proton spectrum produced in the pn interactions. A neutron fragmentation component is observed and the inclusive charge-exchange probability at the nucleon vertex is found to be about 0.4.

1 data table

No description provided.


Eta and omega Meson Production in Medium-Energy pi+- p and K- p Interactions

The Aachen-Berlin-Bonn-CERN-Cracow-London-Vienna-Warsaw collaboration Bartke, J. ; Kirk, H. ; Kaltwasser, J. ; et al.
Nucl.Phys.B 118 (1977) 360-370, 1977.
Inspire Record 110525 DOI 10.17182/hepdata.48967

The production of η(550) and ω(780) mesons is studied in π ± p interactions at 16 GeV/ c and K − p interactions at 10 and 16 GeV/ c . Cross sections for exclusive channels are presented, and for the π + p data differential cross sections are given for quasi-inclusive production where the η or ω is required to be accompanied by charged particles only. Close similarities are observed between η, ω and also ϱ 0 (770) production in terms of longitudinal and transverse variables. By a rough estimate, the η, ω and ϱ 0 inclusive yields are found to be in the ratio 0.32 : 0.85 : 1, respectively, for 16 GeV/ c π + p collisions. For non-peripheral production we estimate this same ratio to be 0.34 : 0.9 : 1.

9 data tables

Axis error includes +- 0.0/0.0 contribution (?////).

Axis error includes +- 0.0/0.0 contribution (?////).

DATA SUPPLIED BY A.A. LEBEDEV.

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Polarization Measurements around the Secondary Dip in pip Elastic Scattering

Auer, P. ; Giese, R. ; Hill, D. ; et al.
Phys.Rev.Lett. 37 (1976) 83-84, 1976.
Inspire Record 945158 DOI 10.17182/hepdata.21039

Polarization in π−p elastic scattering, with emphasis in the region around the secondary dip and also θc.m.=90°, has been measured at 2.93 and 3.25 GeV/c. We observe an interesting sign change in this angular region.

2 data tables

No description provided.

No description provided.


$\pi^- p$ Interactions at 360-GeV/c: Measurement of the Total and Elastic Cross-Sections and the Charged Particle Multiplicity Distribution

Firestone, A. ; Anderson, E.W. ; Chang, V. ; et al.
Phys.Rev.D 14 (1976) 2902, 1976.
Inspire Record 3926 DOI 10.17182/hepdata.24670

In a sample of 108 563 pictures taken with the Fermilab 30-inch hydrogen bubble chamber, exposed to a 360-GeV/c π− beam, we have observed 19 453 interactions in a selected fiducial region. The observed charged multiplicity distribution has been corrected for the effects of scan efficiency, errors in prong count, missed close-in vees, secondary interactions, and neutron stars and for Dalitz pairs. The two-prong events have been corrected for losses at low −t. The total cross section is measured to be 25.25 ± 0.35 mb, and the elastic cross section is 3.61 ± 0.11 mb with an exponential slope of (8.82 ± 0.30) (GeV/c)−2. The average charged-particle multiplicity for inelastic events is 8.73 ± 0.04, and the second moment f2 is measured to be 9.83 ± 0.23.

2 data tables

SYSTEMATIC CORRECTIONS INCLUDED IN ERRORS.

FROM FIT, FORWARD D(SIG)/DT = 31.84 +- 0.68 MB/GEV**2, AND AGREES WITH OPTICAL POINT FROM MEASURED TOTAL CROSS SECTIONS.


Measurement of the electron-Positron Annihilation Cross-Section Into pi+ pi- at the Energies 915-MeV, 990-MeV and 1076-MeV

Cosme, G. ; Courau, A. ; Dudelzak, B. ; et al.
LAL-1287, 1976.
Inspire Record 109771 DOI 10.17182/hepdata.38244

None

1 data table

No description provided.


Study of A2- --> eta pi- in the Reaction pi- p --> pi- pi- pi+ pi0 p at 11.2-GeV/c

The Bologna-Florence-Genoa-Milan-Oxford-Pavia collaboration Forino, A. ; Gessaroli, R. ; Cartacci, A.M. ; et al.
Nuovo Cim.A 35 (1976) 465, 1976.
Inspire Record 109786 DOI 10.17182/hepdata.37635

The analysis of A2−→ηπ− at 11.2 GeV/c confirms that A2− is essentially produced by natural-parity exchange. In the differential cross-section as a function oft′ there is evidence of the dip at smallt′ values. The branching ratio (A2→ηπ)/(A2→ϱπ) is 0.18±0.05.

3 data tables

No description provided.

NUMERICAL VALUES SUPPLIED BY G. THOMPSON. 100 EVENTS IN A2 REGION DEFINED BY 1.18 < M(ETA PI-) < 1.44 GEV.

ROUGH BACKGROUND SUBTRACTION TO REMOVE NON-TRUE ETA EVENTS. FIRST THREE DENSITY MATRIX COMBINATIONS ARE NATURAL-PARITY EXCHANGE, THE REMAINDER BEING UNNATURAL-PARITY EXCHANGE.


Inelastic Diffractive Scattering at FNAL Energies

Ayres, D.S. ; Diebold, Robert E. ; Cutts, D. ; et al.
Phys.Rev.Lett. 37 (1976) 1724, 1976.
Inspire Record 109174 DOI 10.17182/hepdata.21057

Inelastic differential cross sections have been measured for π±p, K±p, and p±p at 140- and 175-GeV/c incident momentum over a |t| range from 0.05 to 0.6 GeV2 and covering a missing-mass region from 2.4 to 9 GeV2. For Mx2 greater than 4 GeV2, the invariant quantity Mx2d2σdtdMx2 was found to be independent of Mx2 at fixed t and could be adequately described by a simple triple-Pomeron form. The values obtained for the triple-Pomeron couplings are identical within statistics for all channels.

1 data table

Data from 140 GeV and 175 GeV are combined. The distributions are fit to CONST*(SLOPE(C=1)*T+SLOPE(C=2)*T**2).


Measurement of the Branching Ratio gamma (anti-p p --> e+ e-) / gamma (anti-p p --> Total) in anti-Proton-Proton Annihilation at Rest

Bassompierre, G. ; Binder, G. ; Dalpiaz, P. ; et al.
Phys.Lett.B 64 (1976) 475-478, 1976.
Inspire Record 109375 DOI 10.17182/hepdata.27616

Analyzing a sample of 220 000 events from an experiment still in progress at the CERN Proton Synchrotron (PS), 60 pairs of electrons with an energy above 700 MeV have been observed. The electrons, produced by annihilation of antiprotons stopped in a liquid-hydrogen target, are detected with optical spark chambers and scintillation counters. Twenty-nine out of these 60 pairs have been found to be collinear; normalizing with respect to the hadronic two-body channels π + π − and K + K − , a braching ratio B ee =Γ( p ̄ p → e + e − )/Γ( p ̄ p → total ) = (3.2 ± 0.9) × 10 −7 has been obtained

1 data table

No description provided.


Energy Dependence of the Reactions K0(L) p --> K0(s) p, pi+ Lambda, pi+ Sigma0 from 1540-MeV to 1610-MeV

Engler, A. ; Keyes, G. ; Kraemer, R.W. ; et al.
Phys.Lett.B 63 (1976) 231-234, 1976.
Inspire Record 3809 DOI 10.17182/hepdata.27639

The reactions K L o p→K S o p, π + Λ , π + Σ o have been measured for center-of-mass energies from 1540 to 1610 MeV. Channel cross sections and coefficients of the Legendre polynomial expansion of the differential cross sections and hyperon polarizations are presented. We see no evidence in the πΛ channel for the suggested 3 2 − resonance at 1580 MeV. The cross section for the K S o p channel shows an energy dependence which is not predicted by the existing phase shift solutions based on charged kaon data.

3 data tables

No description provided.

No description provided.

No description provided.


PRISM Plot Analysis of the Reaction pi- p --> p pi+ pi- pi- at 16-GeV/c

The Aachen-Berlin-Bonn-CERN-Cracow-Heidelberg-Warsaw collaboration Grassler, H. ; Honecker, R. ; Kirk, H.G. ; et al.
Nucl.Phys.B 113 (1976) 365-377, 1976.
Inspire Record 109661 DOI 10.17182/hepdata.35583

A prism plot analysis of the reaction π − p→p π + π − π − at 16 GeV/ c has been made and the results are compared with those obtained in a similar analysis of the reaction π + p→ p π + π + π − at the same energy. The three dominating reaction mechanisms (pion dissociation, reggeon exchange, proton diffraction dissociation) appear to be well separated, while considerable residual overlaps are present inside these classes. The prism plot method is discussed as a means for detecting hidden structures and some evidence is presented for a broad three-pion enhancement around 2 GeV decaying primarily into ϱ 0 π − .

2 data tables

No description provided.

A4(1900) IS CALLED A*(1800) BY AUTHORS. PI+ P CROSS SECTIONS PREVIOUSLY PUBLISHED IN M. DEUTSCHMANN ET AL., NP B99, 397 (1975).