Bell, W.
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Measurement of the Differential Cross-Section and the Spin-Correlation Parameters P,A, and R in the Backward Peak of pi- p --> K0 Lambda at 5-GeV/c

Astbury, P. ; Gallivan, J. ; Jafar, J. ; et al.
Nucl.Phys.B 99 (1975) 30-52, 1975.
Inspire Record 98667 DOI 10.17182/hepdata.31861

We present measurements for the baryon-exchange reaction π − p→ Λ K 0 at 5 GeV/ c over the range − u <2(GeV/ c ) 2 . The differential cross section is obtained from events produced on a liquid hydrogen target. These data are combined with events produced on a butanol polarized target and the parameters P , A , and R are then determined from an analysis of the decay angular distribution of the forward-going Λ. From our data it is possible to determine the magnitudes and the relative phase of the two invariant amplitudes A ′ and B . The consequences for the ratio B / A ′ are discussed in detail.

4 data tables
Table 1

No description provided.

Table 2

THE ERRORS QUOTED IN D(SIG)/DU DO NOT INCLUDE THE ERROR ASSIGNED TO THE OVERALL U-INDEPENDENT CORRECTIONS FACTOR (4.62 +- 0.36), OR OTHER POSSIBLE NORMALIZATION ERRORS.

Table 3

No description provided.

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Photoproduction of Negative Pions on a Polarized Neutron Target in the Resonance Region

Althoff, K.H. ; Beckschulze, H. ; Conrad, R. ; et al.
Nucl.Phys.B 96 (1975) 497-508, 1975.
Inspire Record 99642 DOI 10.17182/hepdata.31932

At the Bonn 2.5 GeV electron synchrotron the first measurements of the target asymmetry for the reaction γ + n ↑ → π − + p have been performed. The negative pions were detected in a magnetic spectrometer at a constant pion c.m. angle of 40° and photon energies between 0.45 GeV and 2.0 GeV. Deuterated butanol was used as target material. The polarization of the deuterons was about 16%. The results show a significant difference from the previously measured π + asymmetry.

1 data table
Table 1

No description provided.


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
Table 1

ASSUMING PREDOMINANTLY NUCLEON SPIN FLIP.

Table 2

No description provided.

Table 3

No description provided.

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Observation of a Spin 4 Neutral Meson with 2-GeV Mass Decaying in pi0 pi0

The Serpukhov-CERN collaboration Apel, W.D. ; Augenstein, K. ; Bertolucci, E. ; et al.
Phys.Lett.B 57 (1975) 398, 1975.
Inspire Record 99595 DOI 10.17182/hepdata.27849

The invariant mass spectrum of neutral meson states from π − p interactions at 40 GeV/ c incident momentum has been investigated in a high statistics experiment performed at the 70 GeV IHEP accelerator. To detect the high energy photons coming from the produced neutral states, a hodoscope spectrometer with a computer on-line was used. A clear structure on the mass spectrum of dipions produced in the reaction π − p→π°π°n is observed at 2 GeV. The decay angular distributions show in this mass region the variation with mass typical of a state with a spin J = 4. The mass of the observed meson is found to be M = (2020±30)MeV and the estimate of the full width is (180±60) MeV.

1 data table
Table 1

No description provided.


Cross-Sections for the Photodisintegration of Deuterium at Intermediate-Energies

Dougan, P. ; Ramsay, V. ; Stiefler, W. ;
Z.Phys.A 276 (1976) 55-64, 1976.
Inspire Record 99793 DOI 10.17182/hepdata.16618

The cross-sections for deuteron photo-disintegration have been measured at nine c.m. angles from 37 to 143 degrees. The minimum and maximum photon energies have been 139 and 832 MeV respectively. The results are in agreement with earlier data above 300 MeV, but are significantly larger below 200 MeV, the discrepancies being up to 50% at the lowest energies measured.

9 data tables
Table 1

MEAN SCATTERING ANGLE FOR THIS DATA GROUP IS 36.9 DEG.

Table 2

MEAN SCATTERING ANGLE FOR THIS DATA GROUP IS 53.1 DEG.

Table 3

MEAN SCATTERING ANGLE FOR THIS DATA GROUP IS 66.4 DEG.

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Photoproduction of the psi Particles

Camerini, U. ; Learned, J.G. ; Prepost, R. ; et al.
Phys.Rev.Lett. 35 (1975) 483, 1975.
Inspire Record 100670 DOI 10.17182/hepdata.21149

The s and t dependence of incoherent ψ(3100) photoproduction from deuterium has been measured at the Stanford Linear Accelerator Center. ψ(3700) photoproduction and ψ(3100) photoproduction from hydrogen have also been measured.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


Charged-Particle Multiplicities in 100 GeV/c $\bar{p}p$ Interactions

Ansorge, R.E. ; Bust, C.P. ; Carter, J.R. ; et al.
Phys.Lett.B 59 (1975) 299-302, 1975.
Inspire Record 2603 DOI 10.17182/hepdata.27765

Results are presented on the topological cross sections obtained for antiproton-proton interactions from an exposure of the Fermilab 30-inch bubble chamber to a 100 GeV/ c negative beam enriched in p 's. The p p inelastic cross section is found to be σ inel = 34.6 ± 0.4 mb, and the average inelastic charged particle multiplicity to be 〈 n 〉 = 6.74 ± 0.05.

3 data tables
Table 1

ERRORS ARE STATISTICAL ONLY EXCEPT FOR 2-PRONG CROSS-SECTIONS.

Table 2

EXPONENTIAL FIT TO ELASTIC T DISTRIBUTION TO CORRECT FOR AN APPARENT LOSS OF EVENTS AT SMALL -T.

Table 3

MOMENTS OF 100 GEV/C AP P MULTIPLICITY DISTRIBUTION.


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
Table 1

Axis error includes +- 10/10 contribution.

Table 2

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.


Study of the Inclusive Reaction K+ p --> K0 Anything at 5-GeV/c, 8.2-GeV/c and 16-GeV/c in the Central Region

Chliapnikov, P.V. ; Gerdyukov, L.N. ; Lugovsky, S.B. ; et al.
Nucl.Phys.B 97 (1975) 1-10, 1975.
Inspire Record 99425 DOI 10.17182/hepdata.31898

The inclusive reaction K + p → K 0 + X is studied at 5, 8.2 and 16 GeV/ c . The energy dependence and the shapes of inclusive spectra in the central region are found to be consistent with double-Regge expansion. With the values obtained for the parameters of the Regge expansion, prediction are made for the behaviour of the cross section at higher energies.

6 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Partial Wave Analysis of the (anti-K0 pi- pi0)-System Produced in the q-Mass Region in K- p --> (anti-K0 pi- pi0) p at 10-GeV/c and 16-GeV/c

The Aachen-Berlin-CERN-London-Vienna collaboration Otter, G. ; Barnham, Keith W J ; Cocconi, Vanna T ; et al.
Nucl.Phys.B 96 (1975) 29-44, 1975.
Inspire Record 98691 DOI 10.17182/hepdata.31971

A partial-wave analysis has been performed of the diffractively produced low-mass ( K ̄ 0 π − π 0 ) system in the reaction K − p → ( K ̄ 0 π − π 0 ) p at 10 and 16 GeV/ c . Thus information complementary to that derived from the K − p → (K − π + π − )p) channel is obtained. The presence of the K ϱ decay mode, besides the dominant K ∗ (890)π mode, for the state J P = 1 + , is confirmed. It is also confirmed that for this 1 + state the assumption of factorization of the amplitude into “production” and “decay” does not hold: the two decay modes K ∗ π and K ϱ have different polarisation properties (helicity is approximately conserved in the t -channel for the first, in the s -channel for the second). The assumption that the ( K ̄ 0 π − π 0 ) system has isospin I = 1 2 has been tested and found to hold. From the cross sections for the various J P states, assuming I = 1 2 , the cross sections for the (K − π + π − ) system are predicted and compared with the experimental ones. In general, agreement is found.

2 data tables
Table 1

No description provided.

Table 2

No description provided.