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Study of the Reactions pi+ p --> pi0 Delta++ (1236), eta Delta++ (1236) and eta-prime Delta++ (1236) at 16-GeV/c

The Aachen-Berlin-Bonn-CERN-Cracow-Heidelberg collaboration Honecker, R. ; Laven, H. ; Becker, L. ; et al.
Nucl.Phys.B 131 (1977) 189-208, 1977.
Inspire Record 122492 DOI 10.17182/hepdata.35195

The reactions π + p giving π 0 Δ ++ (1236), η (549) Δ ++ (1236) and η ′(958) Δ ++ (1236) are studied at 16 GeV/ c . Cross sections, differential cross sections and Δ ++ (1236) spin density matrix elements are presented. The π 0 Δ ++ (1236) differential cross section d σ d t′ indicates a dip towards t ′ = 0 and has a minimum at t ′ ≅ 0.6 GeV 2 . The Δ ++ (1236) spin density matrix elements are consistent with the predictions of the Stodolsky-Sakurai model, except perhaps near the forward direction. For ηΔ ++ (1236), the differential cross section d σ d t′ turns over in the forward direction and presents no further structure. SU(3) sum rules are tested and found to be approximately satisfied. The data agree with factorization of ϱ exchange. The effective A 2 trajectory is calculated and found to be consistent with that reported from the reaction π − p → η n.

7 data tables
Table 1

No description provided.

Table 2

NORMALIZED TO THE TOTAL CROSS SECTION OF 49 MUB.

Table 3

No description provided.

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Inelastic Photoproduction of omega and rho+- Mesons

Nelson, C.A., Jr. ; May, E.N. ; Abramson, J. ; et al.
Phys.Rev.D 17 (1978) 647, 1978.
Inspire Record 4373 DOI 10.17182/hepdata.24401

We report measurements of inelastic photoproduction of ω and ρ± mesons from hydrogen and deuterium at incident photon energies in the range 7.5-10.5 GeV. For ωΔ and ρ−Δ++ production, differential cross sections dσdt′ and spin density matrices are presented. For higher missing masses the cross sections dσdMX2 and invariant structure functions F(x) are also given. The data are compared to a one-pion-exchange model. We conclude that pion exchange is dominant for inelastic ω photoproduction, but unimportant for ρ±.

4 data tables
Table 1

CROSS SECTION PER NUCLEON FOR COMBINED HYDROGEN AND DEUTERIUM DATA ALLOWING FOR A GLAUBER CORRECTION FACTOR OF 0.88 FOR THE DEUTERIUM CROSS SECTIONS.

Table 2

HYDROGEN AND DEUTERIUM DATA COMBINED BY AVERAGING.

Table 3

OBTAINED BY EXTRAPOLATING A FIT TO D(SIG)/DT OVER -T = 0 TO 0.52 GEV**2.

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Production and Decay Properties of f-prime (1514) in K- p Interactions at 4.2-GeV/c

The Amsterdam-CERN-Nijmegen-Oxford collaboration Barreiro, F. ; Diaz, J. ; Gay, J.B. ; et al.
Nucl.Phys.B 121 (1977) 237-250, 1977.
Inspire Record 111490 DOI 10.17182/hepdata.35514

Results are presented for the hypercharge exchange reaction K − p→ f ′(1514) Λ at a beam momentum of 4.15 GeV/ c . Total and differential cross sections have been determined. The Λ polarization and the tensor meson density matrix elements are given as a function of t ′.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

ALL EVENTS WITH 1.46<M(KS KS)<1.60GEV.


Phi-Meson Production in the Reactions pi+- n --> K- K+ n at 6-GeV/c

Cohen, Daniel H. ; Ayres, D.S. ; Diebold, R. ; et al.
Phys.Rev.Lett. 38 (1977) 269, 1977.
Inspire Record 110508 DOI 10.17182/hepdata.21019

A sample of 1200 ϕ mesons produced in the Zweig-rule-forbidden reactions π±N→ϕN shows a flat t distribution (slope=1.7 ± 0.2 GeV−2) and a cross section suppressed by 0.0032±0.0004 relative to π−p→ωn. Natural-parity-exchange ω and ϕ production have similar t dependences, while ω and ϕ production by unnatural-parity exchange differ markedly. Interference between the ϕ and the underlying K¯K S wave indicates substantial nucleon-spin incoherence between the amplitudes for ϕ and S-wave production.

3 data tables
Table 1

Axis error includes +- 10/10 contribution (RES-DEF(RES=PHI,BACK=CORRECTED)).

Table 2

Axis error includes +- 10/10 contribution (RES-DEF(RES=PHI,BACK=CORRECTED)).

Table 3

STATISTICAL ERRORS ONLY.


The Reactions K- p --> pi-+ Sigma+- (1385) at 4.2-GeV/c

The Amsterdam-CERN-Nijmegen-Oxford collaboration Holmgren, S.O. ; Aguilar-Benitez, M. ; Barreiro, F. ; et al.
Nucl.Phys.B 119 (1977) 261-291, 1977.
Inspire Record 110408 DOI 10.17182/hepdata.35566

The reactions K − p→ π − Σ + (1385) and K − p→ π + Σ − (1385) are studied at 4.2 GeV c incident momentum using data from a high statistics bubble chamber experiment corresponding to ∼80 events/μb. The total and differential cross sections are presented. Amplitude analyses are performed and the complete Σ ± (1385) helicity spin density matrices are extracted. The results are compared with the predictions of the additive quark model and exchange degeneracy. A substantial cross section is observed for the reaction K − p→ π + Σ − (1385) in the forward direction, which implies exotic meson quantum numbers in the t -channel. One possible interpretation of this process provides an explanation for the small but significant violations of the additive quark model predictions observed in the reaction K − p→ π − Σ + (1385) at low four-momentum transfer. In the backward direction unnatural parity exchange is shown to give a larger contribution to K − p→ Σ − (1385) π + than natural parity exchange.

11 data tables
Table 1

Axis error includes +- 5/5 contribution.

Table 2

Axis error includes +- 5/5 contribution.

Table 3

Axis error includes +- 5/5 contribution.

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Backward Photoproduction of rho0 and f Between 2.8-GeV and 4.8-GeV

Clifft, R.W. ; Dainton, J.B. ; Gabathuler, E. ; et al.
Phys.Lett.B 64 (1976) 213-216, 1976.
Inspire Record 109693 DOI 10.17182/hepdata.27627

A measurement of backward photoproduction of charged pion pairs on protons is reported. The pion pair mass spectrum shows strong ϱ ° and f production. Data are presented on the u and s dependence for ϱ O and f, together with the decay polarisation for the ϱ O .

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

AVERAGED OVER U RANGE OF EXPERIMENT. NO EVIDENCE FOR ANY LARGE S-WAVE CONTRIBUTION TO THE PI PI SYSTEM IN THE RHO0 MASS REGION (RHO(0S) < -0.03 +- 0.13). U CHANNEL FRAME: Z AXIS IN INCIDENT PROTON DIRECTION IN THE DIPION REST FRAME.


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
Table 1

No description provided.

Table 2

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

Table 3

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


Amplitude Analysis for the Process K- p --> (pi+ pi-) S-Wave Sigma0 (1385)

The Amsterdam-CERN-Nijmegen-Oxford collaboration Barreiro, F. ; Zalewski, K. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 66 (1977) 197-201, 1977.
Inspire Record 110387 DOI 10.17182/hepdata.27588

Transversity amplitudes and spin density matrix elements are determined for the process K − p → (π + π − ) s-wave ϵ 0 (1385). Predictions of the additive quark model and of duality diagrams are tested and found consistent with the data; this is the first information about the applicability of these models to processes where a scalar object is produced at the mesonic vertex.

1 data table
Table 1

No description provided.


Observation of the B Meson in K- p Interactions at 4.2-GeV/c

The Amsterdam-CERN-Nijmegen-Oxford collaboration Flatte, Stanley M. ; Gay, J.B. ; Hemingway, R.J. ; et al.
Phys.Lett.B 64 (1976) 225-229, 1976.
Inspire Record 109851 DOI 10.17182/hepdata.27607

A πω enhancement at 1245 MeV is observed in the reaction K − p → Σ + π − ω. Its properties agree with those of a B meson produced by natural-parity exchange thus establishing a coupling of the B to a K K ∗ system.

2 data tables
Table 1

No description provided.

Table 2

THE DATA FOR B+ PRODUCTION ARE QUOTED FROM CHUNG ET AL., PR D11, 2426 (1975) USING THE SLAC 82 IN HBC. 1.08 < M(PI OMEGA) < 1.38 GEV.


Some 0- 1/2+ and 0- 3/2+ Final States in K- p Reactions at 14.3-GeV/c

Chaurand, B. ; Drevillon, B. ; Gago, J.M. ; et al.
Nucl.Phys.B 117 (1976) 1, 1976.
Inspire Record 109200 DOI 10.17182/hepdata.35604

We present data on K − p reactions leading to the final states K 0 n , π 0 Λ, ηΛ, η'Λ, π − Σ + , K 0 Δ 0 (1230), and π − Σ + (1385) from a bubble chamber experiment at 14.3 GeV/ c K − lab momentum. Total and differential cross sections, Λ and Σ ∓ polarisations in π 0 Λ and π − Σ + final states as well as the Σ + (1385) density matrix elements are given.

9 data tables
Table 1

NORMALIZED TO A TOTAL CROSS SECTION OF 21.5 +- 0.2 MB (GALBRAITH ET AL, PR 138B, 913 (1965)).

Table 2

No description provided.

Table 3

No description provided.

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