Date

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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Polarized Photon Asymmetries in K+ Photoproduction at 16-GeV

Quinn, D.J. ; Rutherfoord, J.P. ; Shupe, M.A. ; et al.
Phys.Rev.Lett. 34 (1975) 543, 1975.
Inspire Record 100595 DOI 10.17182/hepdata.21241

Using a 16-GeV linearly polarized photon beam, we have measured asymmetries in the process γN→K+(Λ+Σ) from hydrogen and deuterium, for square of four-momentum transfer, t, between -0.01 and -0.8 (GeV/c)2. The data show that for −t≳0.1 (GeV/c)2, the cross sections for γp→K+Λ, γp→K+Σ0, and γn→K+Σ− are strongly dominated by natural-parity exchange, as is the case in single-pion photoproduction.

1 data table

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A20 Production by Charge Exchange in pi+ n Interactions at 4-GeV/c

Emms, M.J. ; Jones, G.T. ; Kinson, J.B. ; et al.
Phys.Lett.B 58 (1975) 117-120, 1975.
Inspire Record 98783 DOI 10.17182/hepdata.27809

A partial wave analysis of the reaction π + n → π + π − π 0 p yields an A 0 2 production cross section of 225 ± 30μb for momentum transfer squared < 1 (GeV/ c ) 2 ; the differential cross-section and density matrix are presented and compared with ω 0 production in the light of theoretical models.

2 data tables

Axis error includes +- 10/10 contribution.

ASSUMING NO POPULATION OF HELICITY 2 DENSITY MATRIX ELEMENTS IN T-CHANNEL FRAME. THIS MM = 1+, 1-, 2+, 2- NOTATION REFERS TO THAT SUM OR DIFFERENCE OF HELICITY M DENSITY MATRIX ELEMENTS CORRESPONDING ASYMPTOTICALLY TO NATURAL (+) OR UNNATURAL (-) PARITY EXCHANGE.


The Production of the Omega0 Meson in the Reaction pi+ d --> p (Spectator) p Omega0 at 4-GeV/c

Emms, M.J. ; Kinson, J.B. ; Stacey, B.J. ; et al.
Nucl.Phys.B 98 (1975) 1-28, 1975.
Inspire Record 100077 DOI 10.17182/hepdata.31856

The reaction π + n → ω 0 p has been studied at 4 GeV/ c giving a total cross section of 313 ± 26 μ b. The sample of about 3500 ω 0 events produced in the forward direction has been used to determine the differential cross section and the spin density matrix elements. The effective trajectory for unnatural parity exchange has been determined by a comparison of ϱ 00 d σ /d t at different energies. A comparison of ϱ 00 d σ /d t has been made with the similar data for ϱ 0 production in this experiment allowing π-B exchange degeneracy and ϱ-ω interference to be investigated. These methods result in an unnatural trajectory consistent with that expected for the B-meson. A further study of ϱ-ω interference has been made by comparing the reactions π + n → ω 0 p and π − p → ω 0 n at similar energies. Our results on ω and ϱ production are combined with data on K ∗0 and K ∗0 production at 4 GeV/ c and an SU(3) sum rule relating the production of these four mesons is shown to be satisfied.

13 data tables

ASSUMING PREDOMINANTLY NUCLEON SPIN FLIP.

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Measurement of Differential Cross-Sections for Radiative Pion-Proton Capture in the Second Resonance Region

Weiss, A.J. ; Blasberg, D.J. ; Comiso, J.C. ; et al.
Nucl.Phys.B 101 (1975) 1-18, 1975.
Inspire Record 2234 DOI 10.17182/hepdata.36075

Differential cross-section measurements for π − p → γ n, consisting of three angular distributions at 618, 676 and 718 MeV/ c , and the energy dependence at θ γ = 90° for seven incident pion momenta between 502 and 888 MeV/ c , are presented. Our data qualitatively support recent multipole analyses. Agreement with the Scheffler et al. results for the inverse reaction, γ n → π − p, using a ( π − -recoil p) coincidence technique is good excluding a large violation of time reversal invariance. The agreement with γ n → π − p data obtained using the R ( π − / π + ) ratio technique or a deuterium bubble chamber is only qualitative.

7 data tables

Axis error includes +- 6.6/6.6 contribution.

Axis error includes +- 6.2/6.2 contribution.

Axis error includes +- 6.0/6.0 contribution.

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Inclusive $\pi^0$ Production by High-Energy Protons

Carey, David C. ; Johnson, J.R. ; Kammerud, R. ; et al.
Phys.Rev.D 14 (1976) 1196, 1976.
Inspire Record 99992 DOI 10.17182/hepdata.4894

Measurements of the cross section for the reaction p+p→π0+anything have been completed. The data cover a range of incident proton energies 50-400 GeV, π0 transverse momenta 0.3-4 GeV/c, and laboratory angles 30-275 mrad. The experiment was performed using the internal proton beam at the Fermi National Accelerator Laboratory. A lead-glass counter was used to detect photons from the decay of π0's produced by collisions in thin targets of hydrogen or carbon. Tables of the measured cross sections are presented.

110 data tables

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Production and Decay of xi* (1820) in K- p Reactions at 4.2-GeV/c

The Amsterdam-CERN-Nijmegen-Oxford collaboration Gay, J.B. ; Armenteros, R. ; Berge, J.P. ; et al.
Phys.Lett.B 62 (1976) 477-480, 1976.
Inspire Record 108822 DOI 10.17182/hepdata.27651

Using a high statistics sample of K − p interactions at 4.2 GeV/ c , the production and decay properties of the Ξ ∗ (1820) are discussed. The mass and width are found to be M = (1823 ± 2) MeV and Γ = (21 ± 7) MeV. Evidence is found for Ξ ∗ (2030) in the Σ K ̄ channel and for a new Ξ ∗ at a mass of 2120 MeV in the ΛK − channel.

2 data tables

XI(1820)- PRODUCTION CROSS SECTIONS ARE FOR -UP < 3 GEV**2 AND ARE CORRECTED FOR ISOSPIN AND UNSEEN DECAY MODES.

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Pion Charge Exchange Scattering at High-Energies

Barnes, A.V. ; Mellema, D.J. ; Tollestrup, A.V. ; et al.
Phys.Rev.Lett. 37 (1976) 76, 1976.
Inspire Record 108646 DOI 10.17182/hepdata.21046

We report on a study of pion charge-exchange scattering carried out at Fermilab in the energy range 20 to 200 GeV. The results can be described remarkably well by a simple Regge-pole model. The charge-exchange cross sections in the forward direction lead to a prediction for the difference in total cross sections of π−p and π+p which is in satisfactory agreement with direct measurements of this difference in another experiment at Fermilab.

3 data tables

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

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

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


The Reaction pi- p ---> eta n at High-Energies

Dahl, O.I. ; Johnson, R.A. ; Kenney, R.W. ; et al.
Phys.Rev.Lett. 37 (1976) 80, 1976.
Inspire Record 108647 DOI 10.17182/hepdata.21028

Measurements on the reaction π−p→ηn have been carried out at Fermilab with beam energies from 20 to 200 GeV in the same experiment in which pion charge-exchange scattering was studied. The differential cross sections have a pronounced dip in the forward direction. The data can be described well by a simple Regge-pole model but the resulting A2 trajectory is not degenerate with the ρ trajectory extracted from the charge-exchange data.

3 data tables

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

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

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


Inclusive $\pi^0$ Production at Large Transverse Momentum from $\pi^{\pm} p$ and pp Interactions at 100 and 200 GeV/c

Donaldson, G. ; Gordon, H. ; Lai, K.-W. ; et al.
Phys.Rev.Lett. 36 (1976) 1110, 1976.
Inspire Record 108958 DOI 10.17182/hepdata.21118

We have measured large-transverse-momentum (p⊥) inclusive π0 production at c.m. angles centered near 90° for π±p and pp interactions at 100 and 200 GeV/c. This is the first such measurement using a pion beam. The ratio σ(pp→π0X)σ(πp→π0X) decreases with increasing p⊥ and is independent of energy when expressed as a function of x⊥=p⊥pmax. We compare the data with predictions of various models.

6 data tables

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