Date

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).

More…

Backward Resonance Production in pi- p --> n pi+ pi- at 8-GeV/c

Eisenstein, Bob I. ; Elliott, J. ; Mollet, W. ; et al.
Phys.Rev.D 18 (1978) 1370-1381, 1978.
Inspire Record 136306 DOI 10.17182/hepdata.24374

We have studied backward meson and baryon production in π−p→nπ+π− at 8 GeV/c using a streamer chamber triggered by the detection of the interaction of the neutron in thick-plate optical spark chambers. Our data sample of 866 events is dominated by the quasi-two-body final states Δ−(1232)π+, nρ0, and nf0. We study the differential and total backward cross sections for these states and the decay angular distributions of the resonances. The results for the Δ− and ρ0 indicate that both nucleon and Δ exchange in the u channel are important in their production, while f0 production is, as expected, consistent with nucleon exchange.

5 data tables

No description provided.

BACKWARD DIP.

No description provided.

More…

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.

No description provided.

More…

The Reactions K- p --> Lambda pi0, Lambda eta, Lambda eta' at 4.2-GeV/c

The Amsterdam-CERN-Nijmegen-Oxford collaboration Marzano, F. ; Hemingway, R.J. ; Loverre, P.F. ; et al.
Nucl.Phys.B 123 (1977) 203-222, 1977.
Inspire Record 119257 DOI 10.17182/hepdata.35450

In a high statistics CERN 2 m bubble chamber experiment the differential cross sections and polarizations of the Λ for the reactions K − p → Λπ 0 , Λη , Λη ′ at 4.2 GeV/ c have been measured. The reaction K − p → Λη exhibits a pronounced dip around − t ∼0.5 ( GeV / c ) 2 and all three reactions show a significant backward peaking (− u < 1.0 (GeV/ c ) 2 ). The Λ polarization in the reaction K − p → Λπ 0 is measured to be significantly different from zero throughout most of the available t -range. Forward cross sections enable a determination of R T , the ratio of singlet/octet coupling η 1 KK ∗∗ η 8 KK ∗∗ . Backward cross sections are utilized to estimate the effective η-nucleon coupling constant g η NN 2 over the − u range 0–1.5 ( GeV /c) 2 .

15 data tables

QUOTED VALUES OF THE KINEMATIC LOWER LIMITS OF -T AND -U.

Axis error includes +- 5/5 contribution.

Axis error includes +- 5/5 contribution.

More…

Cross-Sections and Polarizations in the Reactions pi- p --> Lambda K0 and pi- p --> Lambda K* (890) Near the Backward Direction, from 3-GeV/c to 6-GeV/c

Ward, C.E.W. ; Ambats, I. ; Lesnik, A. ; et al.
Phys.Rev.D 16 (1977) 2041, 1977.
Inspire Record 4930 DOI 10.17182/hepdata.24506

We have measured the differential cross sections and Λ polarizations in the reactions π−p→ΛK0 and π−p→ΛK*0 (890) near the backward direction, at 3, 4, 5, and 6 GeV/c. Data equal to several times the world's total sample above 2 GeV/c were recorded. Both reactions are characterized by cross sections falling rapidly with beam momentum, and by large positive Λ polarizations for u′ between 0.0 and 0.6 GeV2. Analysis of π−p→ΛK0 yields an effective Regge trajectory consistent with antishrinkage of the backward peak. Separation into amplitudes of definite-parity-naturality exchange shows the reaction to be dominated by unnatural-parity exchange. The energy behavior of this exchange is, however, not consistent with a single linear baryon Regge trajectory or exchange-degenerate pair of trajectories. An apparent normalization discrepancy between data on π−p→ΛK0 of a CERN-ETH group and other high-statistics data including that of this experiment is discussed.

10 data tables

No description provided.

No description provided.

No description provided.

More…

Results on pi- p Backward Elastic Scattering and Search for pi- p --> d anti-p at 9-GeV/c and 12-GeV/c

Jacholkowski, A. ; Bouquet, B. ; D'Almagne, B. ; et al.
Nucl.Phys.B 126 (1977) 1-10, 1977.
Inspire Record 125076 DOI 10.17182/hepdata.35368

From an experiment done with the CERN Omega spectrometer, triggered by a fast forward proton device, we present results on the differential cross section d σ d u for π − p backward elastic scattering. The d σ d u distribution agrees with an A e Bu law. The compilation of existing results shows a discrepancy between results but the ( d σ d u ) u=0 data fit perfectly an s 2 α 0 −2 dependence, as predicted by a single Δδ Regge trajectory exchange. A search for the reaction π − p → d p , with a fast forward deuteron, which can be produced by a double-baryon exchange mechanism, gives cross-section upper limits of ∼1% of the backward elastic cross section.

4 data tables

UMIN IS 0.0446 GEV**2.

UMIN IS 0.0333 GEV**2.

D(SIG)/DU FITTED FOR 0 < -U < 0.75 GEV**2 TO GIVE SLOPE/INTERCEPT.

More…

A Study of the Final States anti-K0 n, Lambda pi0 and anti-K0 Delta0 in K- p Interactions at 5-GeV/c and 8-GeV/c

Gallivan, J. ; Astbury, P. ; Jafar, J. ; et al.
Nucl.Phys.B 117 (1976) 269-292, 1976.
Inspire Record 110114 DOI 10.17182/hepdata.35539

We present results on three reactions involving neutral final states which were studied in a magnet spark chamber system. These results are: (a) differential cross section with high statistics for K − p → K 0 n at 5 GeV /c (24 000 events) and at 8 GeV/ c (11 000 events) for t′ <2.0 (GeV/ c ) 2 ; (b) differential cross section and polarization for K − p → Λπ 0 (backward peak) at 5 GeV/ c for u ′ < 1.4 GeV/ c ) 2 ; and (c) differential cross section for K − p → K 0 Δ 0 (1232) at 5 GeV /c for t′ < 1.2 ( GeV /c) 2 . We compare our results with existing data and draw some phenomenological conclusions.

7 data tables

Axis error includes +- 0.0/0.0 contribution (?////TP INDEPENDENT CORRECTIONS AT 5 AND 8 GEV ARE 5.143 +- 0.418 AND 4.981 +- 0.436 RESPECTIVELY).

Axis error includes +- 0.0/0.0 contribution (?////TP INDEPENDENT CORRECTIONS AT 5 AND 8 GEV ARE 5.143 +- 0.418 AND 4.981 +- 0.436 RESPECTIVELY).

Axis error includes +- 0.0/0.0 contribution (?////UP INDEPENDENT CORRECTION FACTOR IS 3.840 +- 0.323).

More…

Anti-p n Annihilation Into pi- pi0 Between 1-GeV/c and 1.6-GeV/c

Borreani, G. ; Quassiati, B. ; Rinaudo, G. ; et al.
Nuovo Cim.A 32 (1976) 129-138, 1976.
Inspire Record 113564 DOI 10.17182/hepdata.37637

The annihilation\(\bar pn\) → π−π0 has been studied in a D2 bubble chamber at several beam momenta between 1.0 and 1.6 GeV/c. The cross-section has been measured to be (110±15) μb at an average beam momentum of 1.3 GeV/c. The study of the angular distribution shows the presence of anL = 3 wave.

3 data tables

NO CORRECTIONS APPLIED FOR SPECTATOR PROTON MOMENTUM CUT NOR FOR ANY RESCATTERING IN DEUTERIUM NUCLEI.

No description provided.

DIP AT -U = 0.4 TO 0.6 (REFLECTING DIP NEAR COS(THETA) = -0.8).


Elastic Backward Scattering of Negative Pions on Protons at 25-GeV/c and 38-GeV/c

Babaev, A. ; Brakhman, E. ; Danilov, M. ; et al.
Phys.Lett.B 67 (1977) 351, 1977.
Inspire Record 109000 DOI 10.17182/hepdata.39798

The backward elastic scattering reaction π − p → p π − at momenta 25 and 38 GeV/ c have been measured using a magnetic spectrometer with hybrid chambers. The experimental data on the dependence of the cross section d σ /d u on the momentum transfer u as well as the energy dependence d σ /d u at u = 0 are given.

2 data tables

Precision Measurement of n p Charge Exchange Cross-Section at 647-MeV

Evans, M.L. ; Glass, G. ; Hiebert, J.C. ; et al.
Phys.Rev.Lett. 36 (1976) 497-500, 1976.
Inspire Record 112959 DOI 10.17182/hepdata.21088

The differential cross section for n−p elastic scattering in the angular region 145°<θc.m.<180° has been measured with high statistical accuracy using the monoenergetic neutron beam at Clinton P. Anderson Meson Physics Facility. The results differ significantly from previous Dubna and Princeton-Pennsylvania Accelerator results but agree reasonably well with recent Saclay data except at extreme backward angles.

1 data table

No description provided.