von Dardel, G.
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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.


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.


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.


Small Angle Photon Scattering on Complex Nuclei

Criegee, L. ; Franke, G. ; Giese, A. ; et al.
Nucl.Phys.B 121 (1977) 38-44, 1977.
Inspire Record 118811 DOI 10.17182/hepdata.35513

Photons of 3 GeV and 5 GeV were scattered on 7 different elements, ranging from Be to Au, and detected with a pair spectrometer. The angular distributions show diffractive patterns consistent with known nuclear sizes. Forward cross sections are 20–30% lower than expected from an A 2 dependence. This shadowing effect is qualitatively explained by photon interactions via intermediate hadronic states.

25 data tables
Table 1

SYS ERR = 3.01 PCT, NORM ERR = 1.63 PCT.

Table 2

SYS ERR = 2.94 PCT, NORM ERR = 1.60 PCT.

Table 3

SYS ERR = 5.58 PCT, NORM ERR = 1.61 PCT.

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Cross-Sections of Annihilation and Inelastic Final States for anti-p p Interactions at 9.1-GeV/c

The LIVERPOOL-STOCKHOLM collaboration Gregory, P.S. ; Johnson, P. ; Mason, P. ; et al.
Nucl.Phys.B 119 (1977) 60-76, 1977.
Inspire Record 123859 DOI 10.17182/hepdata.8340

Topological and channel cross sections are given for annihilation and inelastic final states produced in p p interactions at 9.1 GeV/c. Cross sections for prominent resonances in specific channels and charged pion, ϱ 0 and Δ ++ inclusive cross sections are also presented.

6 data tables
Table 1

No description provided.

Table 2

FITTED FORWARD D(SIG)/DT = 153 +- 8 MB/GEV**2.

Table 3

CHANNEL CROSS SECTIONS FOR 2, 4, 6, AND 8 PRONG REACTIONS.

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Study of the Reaction d (p, pi+) t at t(p) = 410-MeV, 605-MeV and 809-MeV

Aslanides, E. ; Bertini, R. ; Bing, O. ; et al.
Phys.Rev.Lett. 39 (1977) 1654-1656, 1977.
Inspire Record 126515 DOI 10.17182/hepdata.20981

Pion production on a CD2 target has been measured using the high-resolution magnetic spectrometer SPES I. Differential cross sections for the reaction D(p, π+)T have been determed at Tp=410, 605, and 809 MeV. The present data, together with previous results establish a complete angular distribution of the reaction D(p, π+)T at ∼ 600 MeV and the energy dependence of the differential cross section for this reaction at several constant momentum transfers.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Properties of Inclusive $\pi^{\pm}$ Production in 100 GeV/c Antiproton-Proton Interactions

Whitmore, J. ; Oh, B.Y. ; Pratap, M. ; et al.
Phys.Rev.Lett. 38 (1977) 996, 1977.
Inspire Record 118838 DOI 10.17182/hepdata.20985

Inclusive spectra are presented for π± production in 100-GeV/cp¯p interactions. The rapidity distribution for the difference (p¯p−pp) approximately scales as the difference in total cross sections in the fragmentation region between 12 and 100 GeV/c and exhibits an approximate s−12dependence in the central region.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Tests of Factorization from Single and Double Pion Production in 100 GeV/c $\bar{p}p$ and pp Collisions.

Rushbrooke, John G. ; Ward, D.R. ; Ansorge, R.E. ; et al.
Phys.Rev.Lett. 39 (1977) 117-120, 1977.
Inspire Record 123282 DOI 10.17182/hepdata.20980

Single- and double-pion inclusive spectra are presented for 100-GeV/c p¯p interactions and compared with related pp data. Double-fragmentation distributions are shown to be understood within a Mueller-Regge framework as a product of single-fragmentation distributions. Consideration of pp and p¯p−pp distributions shows factorization to hold in Pomeron and in Reggeon exchanges independently.

1 data table
Table 1

No description provided.


$\pi^- p$ at 205 GeV/c: Multiplicities of Charged and Neutral Particles Production of Neutral Particles

Ljung, D. ; Bogert, D. ; Hanft, R. ; et al.
Phys.Rev.D 15 (1977) 3163, 1977.
Inspire Record 111665 DOI 10.17182/hepdata.24616

A study of 205-GeV/c π−p interactions has been made with a 48 800-picture exposure in the bare Fermilab 30-inch hydrogen bubble chamber. The average number of charged particles produced per inelastic interaction is 7.99±0.06. The elastic cross section is 3.18±0.13 mb and the total cross section is 24.19±0.44 mb. The inclusive cross sections for neutral-particle production are: σ(γ)=171.3±15.3 mb, σ(KS0)=3.64±0.61 mb (x<0.3), σ(Λ)=1.71±0.34 mb (x<0.3), and σ(Λ¯)=0.59±0.23 mb (x<0.1). The average number of π0's produced per inelastic collision is consistent with a linear rise with the number of charged particles, and about equal to the number of produced π− or π+. The average number of K0's, Λ's, and Λ¯'s is consistent with very little dependence on the number of charged particles. General characteristics of neutral-particle production are presented and compared with other experiments. For each topology the produced neutral energy is ∼13 of the incident energy.

8 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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