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Channel Cross-Sections of K- p Reactions from 1.934-GeV/c to 2.516-GeV/c

de Bellefon, A. ; Berthon, A. ; Billoir, Pierre ; et al.

Nuovo Cim.A 41 (1977) 451, 1977.

Inspire Record 119820 DOI 10.17182/hepdata.37597

The results on total channel cross-sections obtained in the 2 m HBC exposed to a separated K− beam at the CERN PS are presented here. The total cross-sections for each channel are given at seven incident K− momenta between 1.934 and 2.516 GeV/c.

1 data table

Table 1

CORRECTED FOR ALL POSSIBLE V DECAY MODES. STATISTICAL ERRORS ONLY.

Study of Quasielastic Reactions of Neutrino and anti-neutrino in Gargamelle

Bonetti, S. ; Carnesecchi, G. ; Cavalli, D. ; et al.

Nuovo Cim.A 38 (1977) 260-270, 1977.

Inspire Record 124163 DOI 10.17182/hepdata.37598

The quasi-elastic cross-sectionsσeltot and dσ/dq2 for the reactions 1) νn → μ−p and 2)\(\overline v \) → μ+n have been measured by using the data of the ν Gargamelle collaboration. 687 ν events, candidates for reaction 1), and 476\(\overline v \) events, candidates for the reactions 2), have been used for the analysis. Because the ν and\(\overline v \) interactions are on nuclei, suitable corrections for nuclear effects have been taken into account. In the framework of the «usual»V −A theory, by assuming for the axial form factor the dipolar formFA(q2)=1.23/(1 +q2/MA/2)2, our data have been fitted to the differential cross-section dσ/dq2 integrated over the ν and\(\overline v \) energy spectra and to the total cross-sectionσeltot as a function of the ν,\(\overline v \) energy to determine the best value for the parameterMA.

1 data table

Table 1

Measured Quasi-Elastic total cross section.

Small Angle Compton Scattering on Hydrogen and Deuterium

Criegee, L. ; Franke, G. ; Giese, A. ; et al.

Nucl.Phys.B 121 (1977) 31-37, 1977.

Inspire Record 118810 DOI 10.17182/hepdata.35467

We have measured elastic scattering of 5 and 6 GeV photons on hydrogen and deuterium in the angular range 10–50 mrad. On hydrogen we observe a forward diffraction peak with a slope of 8.5 (GeV/ c ) −2 . The extrapolated forward cross sections in units μ b/(GeV/ c ) 2 are 0.82 ± 0.04 at 5 GeV and 0.79 ± 0.04 at 6 GeV. They are consistent with the calculated amplitudes obtained from total cross section measurements via the optical theorem and dispersion relations assuming negligible contributions of spin-dependent amplitudes. Deuterium cross sections show a transition from coherent scattering at low | t | to incoherent scattering at higher | t |. They indicate that the isovector exchange amplitude a 1 is very small compared to the isoscalar a 0 . We obtain |a 1 | 2 /|a 0 +a 1 | 2 =0.13±0.09 , Re (a 0 a ∗ 1 )/|a 0 +a 1 | 2 =0.0±0.03, at 5 GeV , |a 1 | 2 /|a 0 +a 1 | 2 =−0.12±0.15 , Re (a 0 a ∗ 1 )/|a 0 +a 1 | 2 =0.10±0.04, at 6 GeV .

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Measurement of the Polarization Parameter in 24-GeV/c Proton Proton Elastic Scattering at Small Momentum Transfers

Crabb, D.G. ; Green, K. ; Kyberd, P. ; et al.

Nucl.Phys.B 121 (1977) 231-236, 1977.

Inspire Record 124254 DOI 10.17182/hepdata.35517

A measurement of the polarization parameter P 0 in pp elastic scattering has been made at 24 GeV/ c over the range | t | = 0.1 to 0.9 (GeV/ c ) 2 , positive, falling to zero around | t | = 0.8 (GeV/ c ) 2 . For the range 0.1 ⪕ |t| ⪕ 0.4 GeV /c) 2 , P 0 is constant at about 0.03.

1 data table

Table 1

Axis error includes +- 5/5 contribution (SYS-ERR DUE MAINLY TO UNCERTAINTY IN KNOWLEDGE OF ABSOLUTE VALUE OF TARGET POLARIZATION).

Omega-Meson Production by Virtual Photons

Joos, P. ; Ladage, A. ; Meyer, H. ; et al.

Nucl.Phys.B 122 (1977) 365-382, 1977.

Inspire Record 118808 DOI 10.17182/hepdata.35453

Qausi-elastic ω production by ep scattering in the kinematic region 0.3. < Q 2 < 1.4 GeV 2 and 1.7 < W < 2.8 GeV was studied using a streamer chamber at DESY. The production angular distribution for γ V p → ω p has a strong non-peripheral component for W < 2 GeV. The ω production cross section falls by a factor of 4 as W changes from 1.7 to 2.8 GeV. In contrast the cross section for ω production with | t | < 0.5 GeV 2 is W independent between 1.7 and 2.8 GeV and for W > 2.0 GeV consistent in both W and Q 2 dependence with the predictions of a model based on one-pion exchange and diffraction.

5 data tables

Table 1

FOR ALL T-VALUES. THE GAMMA* P TOTAL CROSS SECTION WAS TAKEN FROM A FIT TO THE DATA OF S. STEIN ET AL., PR D12, 1884 (1975). 'PPD'.

Table 2

'PPD'. PERIPHERAL OMEGA PRODUCTION.

Table 3

No description provided.

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Measurement of Differential Cross-Section and Polarization in the Backward Peak of the Reactions pi- p --> Lambda K0 and pi- p --> Lambda K* (890) at 8-GeV/c

Brundiers, H. ; Hartung, R. ; Runge, K. ; et al.

Nucl.Phys.B 119 (1977) 349-361, 1977.

Inspire Record 123952 DOI 10.17182/hepdata.35527

Differential cross sections and polarizations have been measured for the backward peaks in the reactions π − p →Λ K 0 and π − p →Λ K ∗ (890) at 8 GeV/c. The experiment was performed with a liquid hydrogen target at the ω spectrometer. The cross sections for u′>−2 ( GeV /c) 2 are 0.27 ± 0.03 μ b for π − p →Λ+ K 0 and 0.55±0.07 μ b for π − p →Λ K ∗0 . Large positive Λ polarization was observed in both reactions for u ′>−0.5 (GeV/ c ) 2 . The dominant production mechanism was found to be unnatural baryon exchange.

3 data tables

Table 1

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

Table 2

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

Table 3

No description provided.

Study of the Reactions pi+ p --> pi+ p pi0 pi0 and pi+ p --> pi+ p pi0 pi0 pi0 at 3.5-GeV

Mine, P. ; Irwin, G. ; Jacquet, F. ; et al.

Nucl.Phys.B 124 (1977) 365-390, 1977.

Inspire Record 125737 DOI 10.17182/hepdata.35428

We study the reactions π + p → π + p nπ 0 ( n = 2, 3) at 3.5 GeV/ c , with 940 and 143 events, respectively. Complete final states are recorded and measured in a heavy liquid bubble chamber. We find the cross sections: sigma;(π + p → π + p 2π 0 ) = 1300 ± 210 μ b , σ(π + p → π + p 3π 0 ) = 320 ± 70 μ b , below the values predicted by statistical models from charged pion data. The mass spectra are given and channel separations are performed using Van Hove variables. Our results are in agreement with charged pion experiments. We present a description of the 3 π 0 system, with 61 events. Under certain hypotheses a spin-parity analysis favours 0 − at low mass and 1 − at high mass.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Analysis of the omega pi- System Produced in the Reaction pi- p --> pi- pi- pi+ pi0 p at 11.2-GeV/c

Gessaroli, R. ; Quareni-Vignudelli, A. ; Berti, S. ; et al.

Nucl.Phys.B 126 (1977) 382-396, 1977.

Inspire Record 119128 DOI 10.17182/hepdata.41905

The ωπ − mass spectrum, in the reaction π −p → ωπ − pat 11.2 GeV/ c , shows the production of the B − meson with a cross section of 27 ± 5 μb as well as a clear enhancement around 1670 MeV. In the differential cross section for B − production, there is a strong forward peak and a change of slope at t ' t 0.2 GeV 2 .

3 data tables

Table 1

CORRECTED FOR BACKGROUND AND OMEGA TAILS.

Table 2

No description provided.

Table 3

ABS(D-WAVE/S-WAVE) = 0.4 +- 0.1 FOR B DECAY.