Partial Wave Analysis of Backwardly Produced Three Pion Systems in $K^- p$ Interactions at 4.2-{GeV}/$c$

The Amsterdam-CERN-Nijmegen-Oxford collaboration Foster, B. ; Grossmann, P. ; Lamb, P.R. ; et al.
Nucl.Phys.B 187 (1981) 231-253, 1981.
Inspire Record 155773 DOI 10.17182/hepdata.34261

We report on the results of a partial-wave analysis of the 3π system produced by baryon exchange in the reaction K − p→ Σ − π + π + π − at 4.2 GeV/ c . We confirm the existence of an enhancement in the 1 + S( ϱπ ) wave as previously established from a Dalitz plot analysis of the same data. The phase variation of this wave is found to be consistent with that expected for a resonance and thus the enhancement is identified with A 1 production. No clear signal for this state is found in either the reaction K − p→ Σ + π + π + π − π − or K − p→ Λπ + π − π 0 . We also find production via baryon exchange of the A 2 in all three reactions and the ω and ω ∗ (1975) in the third reaction.

2 data tables

SIMPLE BREIT-WIGNER RESONANCE FITS. CORRECTED FOR UNOBSERVED DECAY MODES.

No description provided.


Xi (1320) and Xi (1530) Production in $K^- p$ Interactions at 4.2-{GeV}/$c$

The Amsterdam-CERN-Nijmegen-Oxford collaboration Mazzucato, M. ; Pennino, D. ; Aguilar-Benitez, M. ; et al.
Nucl.Phys.B 178 (1981) 1-30, 1981.
Inspire Record 153470 DOI 10.17182/hepdata.34384

The reactions K − p → Ξ 0 − (1320) K 0 + , Ξ − (1320) K + (890), Ξ 0 − (1530) K 0 − and Ξ 0 − (1530) K 0 + (890) are studied at 4.2 GeV/ c incident momentum. The data come from a high-statistics bubble chamber experiment with a sensitivity of ∼ 133 events/ μ b. Total anddifferential cross sections are presented. The results are compared to the SU(3)-related processes K + p → pK + and K + p → pK + (890) in the backward hemisphere. In the forward hemisphere “forbidden” peaks are observed and current ideas about them are discussed.

16 data tables

FULLY CORRECTED FOR ALL CUTS AND UNSEEN DECAY MODES.

TOTAL, FORWARD AND BACKWARD CROSS SECTIONS. FULLY CORRECTED FOR CUTS, K0 AND LAMBDA UNSEEN DECAY MODES AND OTHER K*(892) AND XI(1530P13) DECAYS. IN 3-BODY FINAL STATES, THETA REFERS TO THE PI-K SYSTEM.

No description provided.

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Production and Decay Properties of the $D(1285)$ Meson in $K^- p$ Interactions at 4.2-{GeV}/$c$

The Amsterdam-CERN-Nijmegen-Oxford collaboration Gurtu, A. ; Gavillet, P. ; Armenteros, R. ; et al.
Nucl.Phys.B 151 (1979) 181-192, 1979.
Inspire Record 133183 DOI 10.17182/hepdata.34791

We have studied the production and decay of the D(1285) meson in the reaction K − p→ Λ D at an incident K − momentum of 4.2 GeV/ c . The cross section for this reaction is 11 ± 3 μ b and the branching ratios D→ KK π /D → ηππ and D → 4 π /D → ηππ are found to be 0.42 ± 0.15 and 0.7 ± 0.5, respectively. The proportion of D → ηπ + π − going through the intermediate δ ± π ∓ states is 0.72 ± 0.15. Forward and backward exchange mechanisms are found to contribute in the ratio 3 : 2.

1 data table

ABOUT 60 PCT OF THE D(1285) PRODUCTION OCCURS IN THE FORWARD HEMISPHERE.


Backward Production of the $B$ Meson in $K^- p$ Interactions at 4.2-{GeV}/$c$

The Amsterdam-CERN-Nijmegen-Oxford collaboration Gavillet, P. ; Dionisi, C. ; Gurtu, A. ; et al.
Phys.Lett.B 78 (1978) 158-161, 1978.
Inspire Record 131673 DOI 10.17182/hepdata.27430

The backward production of the B(1235) meson is studied in the reaction K − p → Σ − π + ω . This reaction is observed in the final state Σ − π + π + π − π 0 . A π + ω mass enhancement is visible in the region of the B meson for events with small | u |K − → Σ − ) squared four-momentum transfer. The properties of the enhancement agree with those of the B meson. The cross section for K − p → Σ − B + at 4.15 GeV c incident K − momentum is (3.2 ± 0.5) μb . The backward production of the B meson is compared with similar baryon exchange productions of the A 1 and C(Q 1 ) axial vector mesons observed in the same experiment.

2 data tables

No description provided.

No description provided.


The Reactions $K^- p \to$ Pseudoscalar Meson $\Lambda(1520)$ at 4.2-{GeV}/$c$

The Amsterdam-CERN-Nijmegen-Oxford collaboration Barlag, S.J.M. ; Blokzijl, R. ; Jongejans, B. ; et al.
Nucl.Phys.B 149 (1979) 220-236, 1979.
Inspire Record 130106 DOI 10.17182/hepdata.34820

The total and differential cross sections of the reactions K − p → π 0 Λ (1520), ηΛ(1520) and η′ Λ(1520) have been measured. Prominent forward peaks are onserved in all three reactions. The first reaction shows also a backward peak. The spin density matrix elements of the Λ(1520) in this reaction are determined. For forward production the results show a remarkable alignment of the Λ(1520) corresponding to an M2 transition in the model of Stodolsky-Sakurai for 3 2 − baryon production.

12 data tables

TOTAL (FORWARD AND BACKWARD) CROSS SECTIONS. THE ERRORS ARE MAINLY SYSTEMATIC.

-TP = (-T - 0.04 GEV**2). MAX(-T) - MIN(-T) = 5.75 GEV**2.

-UP = (-U - 0.20 GEV**2).

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Backward Production of a Spin Parity 1+ $K \rho$ Resonance at 1.28-{GeV}

The Amsterdam-CERN-Nijmegen-Oxford collaboration Gavillet, P. ; Diaz, J. ; Dionisi, C. ; et al.
Phys.Lett.B 76 (1978) 517-522, 1978.
Inspire Record 130237 DOI 10.17182/hepdata.27442

A ( K π π ) + mass enhancement is observed in the reactions K − p → Ξ −K o + π + π o − when events with a small (K − → Ξ − ) four momentum transfer squared are selected. The signal is also visible in the reaction K − p → Ξ − π + + neutrals. The enhancement, centered at 1.28 GeV, is seen to decay preferentially into Kϱ with spin-parity J P = 1 + . The cross section for K − p→ Ξ − C + (1.28) with C + → K ϱ at 4.15 GeV/c incident K − momentum is (6.2 ± 0.6) μ b.

1 data table

ASSUMING ISOSPIN HALF FOR C(1280)+ AND C(1400)+. FOR C(1280)+, D(SIG)/DU HAS SLOPE OF 1.60 +- 0.30 GEV**-2. THESE AXIAL VECTOR RESONANCES ARE HERE ENCODED AS QLOW(1240)+ AND QHIGH(1340)+.


Nonstrange Vector Meson Production in K- p Interactions at 4.2-GeV/c

The Amsterdam-CERN-Nijmegen-Oxford collaboration Losty, M.J. ; Holmgren, S.-O. ; Aguilar-Benitez, M. ; et al.
Nucl.Phys.B 133 (1978) 38, 1978.
Inspire Record 121759 DOI 10.17182/hepdata.8294

The vector meson production, hypercharge exchange reactions K − p → ( φ , ω , ϱ ) Λ and ( φ , ϱ ) Σ 0 are studied at 4.2 GeV/ c incident momentum. The data come from a high statistics bubble chamber experiment with a sensitivity of ∼ 120 events/μb. Total and differential cross sections are presented. The vector meson density matrix elements and hyperon polarization are investigated as functions of momentum transfer. Amplitude analyses are performed for all five reactions. The results are compared with duality and quark model predictions, as well as used to test current ideas in two-body phenomenology.

38 data tables

ERRORS INCLUDE THE 5 PCT MODEL ERROR BUT NOT THEORETICAL RESONANCE PARAMETRIZATION ERRORS.

No description provided.

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Backward Production of a Spin Parity 1+ rho pi Enhancement at 1.04-GeV

The Amsterdam-CERN-Nijmegen-Oxford collaboration Gavillet, P. ; Berge, J.P. ; Ferrando, A. ; et al.
Phys.Lett.B 69 (1977) 119, 1977.
Inspire Record 120469 DOI 10.17182/hepdata.27551

A spin-parity 1 + ϱπ enhancement is observed for the 3π mass spectrum in the reaction K − p → Σ − π + π + π − where events with a small (K − → Σ − ) momentum transfer are selected. The mass (1040 MeV) and width (230 MeV) of this enhancement are reminiscent of the A 1 → ϱπ bump which has mainly been observed in the diffractive-like processes. The cross section for this enhancement at 4.15 GeV/ c incident K − momentum is (3.6 ± 0.5) μ b.

2 data tables

No description provided.

No description provided.


Xi* (2030) Production in K- p Reactions at 4.2-GeV/c

The Amsterdam-CERN-Nijmegen-Oxford collaboration Hemingway, R.J. ; Armenteros, R. ; Berge, J.P. ; et al.
Phys.Lett.B 68 (1977) 197, 1977.
Inspire Record 119852 DOI 10.17182/hepdata.27567

Significant production of (2030) is observed in the channel K − p → (Σ K − K + from a high statistics bubble chamber exposure at 4.2 GeV/ c . The mass and width are determined to be 2024 ± 2 MeV and 16 ± 5 MeV respectively. Apart from Σ K , the only other decay channel is found to be Λ K .

1 data table

ASSUMING XI(2030) HAS ISOSPIN HALF, CROSS SECTIONS CORRECTED FOR UNOBSERVED NEUTRAL DECAYS.


A Partial Wave Analysis of the 3 pi System in the Reaction K- p --> pi+ pi- pi0 Lambda at 4.2-GeV/c

The Amsterdam-CERN-Nijmegen-Oxford collaboration Cerrada, M. ; Wagner, F. ; Chaloupka, V. ; et al.
Nucl.Phys.B 126 (1977) 241, 1977.
Inspire Record 119497 DOI 10.17182/hepdata.35366

A partial-wave analysis of the (3 π ) 0 system produced peripherally in the reaction K − p → π + π − π 0 Λ at 4.2 GeV/ c is presented. The observation of the weak Λ decay allows a determination of all the transversity production amplitudes except for two phases. The production of known resonances having decay modes other than 3 π is used to test the isobar model ansatz. Significant ω(783), φ(1020) and A 2 (1310) production is observed. The spin parity of the ω ∗ (1675) is established as 3 − . No evidence for production of other resonances, such as axial vector-mesons, is found.

1 data table

No description provided.