Engelmann, T.R.
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New Limits for the Exotic Exchange Reaction pi- p --> K+ Sigma- at 5-GeV and 8-GeV

Dekkers, D. ; Guillaud, J.P. ; Lepeltier, V. ; et al.
Nucl.Phys.B 131 (1977) 72-79, 1977.
Inspire Record 126514 DOI 10.17182/hepdata.35221

Measurement of the exotic exchange reaction π − p → K + Σ − has been performed at 5 and 8 GeV, in the −0.015 to −0.13 and −0.009 to −0.15 (GeV/ c ) 2 range of t repectively. We give the value near t = 0 of the differential cross section at 5 GeV, 21 −21 +76 nb/(GeV/ c ) 2 , and an upper limit (< 37 nb/GeV/ c ) 2 ) at 8 GeV. As a check the measured differential cross section is given at both energies for the reaction π + p → K + Σ + in the same range of t ★★ ★★ Results presented here were included in the thesis of Doctorat d′Etat by M.N. Minard, Orsay, France, 1976. .

2 data tables
Table 1

No description provided.

Table 2

No description provided.


One, Two, and Three Particle Distributions in p p Collisions at 205-GeV/c

Kafka, T. ; Singer, R. ; Cho, Y. ; et al.
Phys.Rev.D 16 (1977) 1261, 1977.
Inspire Record 110667 DOI 10.17182/hepdata.24609

Results of a Fermilab experiment using the 30-in. hydrogen bubble chamber are reported, with the main emphasis on pion production in the central region. Single-particle inclusive and semi-inclusive distributions in rapidity, Feynman x, and pT2 for both π− and π+ are presented and compared with results of other experiments. Two-particle distributions are investigated using the correlation-function formalism. The relation between inclusive and semi-inclusive correlation functions is discussed. The semi-inclusive correlation functions in rapidity are found to have short-range character compatible with the ideas of independent-cluster-emission models. Evidence for effects due to Bose-Einstein statistics of like particles is found by comparing the joint correlation function in rapidity and azimuthal angle, as well as the charged multiplicity associated with transverse momentum in the like- and unlike-charge combinations. Data on the average associated transverse momentum are also presented. The inclusive and semi-inclusive three-particle distributions are presented for all charge combinations. The inclusive three-particle correlations are found to be small for events with more than four particles in the final state. Two independent ways were found in which three-particle densities can be expressed in terms of one- and two-particle densities.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


The Inclusive Reactions $p + n \to p + X$ and $\pi^+ + n \to p + X$ at 100-GeV/c

Hanlon, J. ; Brody, A. ; Engelmann, R. ; et al.
Phys.Rev.Lett. 37 (1976) 967, 1976.
Inspire Record 108156 DOI 10.17182/hepdata.21040

We have measured the inclusive cross section for the reactions p+n→p+X and π++n→p+X at 100 GeV/c in the kinematic region |t|<1.0 GeV2. The data were obtained from an exposure of the Fermilab 30-in. deuterium-filled bubble chamber to a tagged positively charged beam. The differential cross sections for these reactions are observed to scale in the ratio of the pn and π+n total cross sections and to be consistent with the predictions of a Reggeized one-pion-exchange model.

6 data tables
Table 1

No description provided.

Table 2

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Table 3

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Rho0 Production in 205-GeV/c p p Interactions

Singer, R. ; Fields, T.H. ; Hyman, L.G. ; et al.
Phys.Lett.B 60 (1976) 385-388, 1976.
Inspire Record 2818 DOI 10.17182/hepdata.6484

Inclusive and semi-inclusive ρ 0 production are studied in 205 GeV/ c pp interactions. The number of ρ 0 per inelastic event is 0.33 ± 0.06, so that (13 ± 2)% of the π − are products of ϱ 0 decay. The ρ 0 are found to be produced mainly near y = 0 and tend to have larger average transverse momentum than do pions.

6 data tables
Table 1

No description provided.

Table 2

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Table 3

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Study of the Reaction $pp \to \Delta^{++} (1236) + X^0$ at 205 GeV/c

Barish, S.J. ; Derrick, M. ; Musgrave, B. ; et al.
Phys.Rev.D 12 (1975) 1260, 1975.
Inspire Record 98475 DOI 10.17182/hepdata.24865

We have studied inclusive Δ++(1236) production for |tpΔ|<1.0 (GeV/c)2 in a 50 000 picture exposure of the 30-inch hydrogen bubble chamber to a 205 GeV/c proton beam. The inclusive Δ++ cross section for one hemisphere in the center-of-mass system is (1.30±0.14) mb. The mean charged multiplicity of the system recoiling off the Δ++ is in agreement with that for laboratory π−p interactions at the same energy in the center-of-mass frame. The inclusive Δ++ production is compared to inclusive Λ0 and proton production in the same experiment. The connection between Δ++ production and diffraction is discussed. We find that not all Δ++ come from the decay of a diffractively-produced state. The PT2 distribution for the Δ++ has a slope of (10.5±0.9) (GeV/c)−2 for PT2≲0.2 (GeV/c)2. This slope, together with the decay angular distribution of the Δ++ at small momentum transfer, suggests a strong pion-exchange contribution to the inclusive process. We compare the data to the expectation of a triple-Regge model with ρ- and π-exchange contributions.

5 data tables
Table 1

No description provided.

Table 2

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Table 3

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Approximate Scaling of Multiplicity Distributions as a Function of Missing Mass

Barshay, S. ; Engelmann, R. ; Kafka, T. ; et al.
Phys.Rev.Lett. 32 (1974) 1390, 1974.
Inspire Record 1032 DOI 10.17182/hepdata.21933

Data from p+p→p+X at 102, 205, and 405 GeV and from π−+p→p+X at 205 GeV exhibit an approximate scaling property in the charged-prong multiplicity distributions as a function of the missing mass for the range 5<~MX<~13 GeV.

1 data table
Table 1

No description provided.


Updated Charged-Particle Multiplicity Distribution from 205-GeV/c Proton Proton Interactions

Barish, S. ; Cho, Y. ; Colley, D.C. ; et al.
Phys.Rev.D 9 (1974) 2689, 1974.
Inspire Record 609 DOI 10.17182/hepdata.21974

The charged-particle multiplicity distribution in 205−GeVc proton-proton interactions is presented. In addition, the total diffractive contributions to each charged multiplicity are estimated assuming a factorizable Pomeron.

1 data table
Table 1

THE TOTAL CROSS SECTION NORMALIZATION COMES FROM THIS AND OTHER EXPERIMENTS.


Study of inclusive gamma and pi0 production in 12.4-gev/c p p interactions

Campbell, J.H. ; Charlton, G. ; Engelmann, R. ; et al.
Phys.Rev.D 8 (1973) 3824-3828, 1973.
Inspire Record 93275 DOI 10.17182/hepdata.22002

From an exposure of the Argonne National Laboratory 12-foot bubble chamber to a beam of 12.4-GeV/c protons we have obtained a 3649-event sample of the reaction pp→γ+anything, where we observe photon conversions into e+e− pairs in the liquid hydrogen. We find that the invariant cross section for this reaction does not separate in its x and P⊥ dependence at our energy. By setting upper bounds on the cross sections for inclusive η and Σ0 production, we show that π0 decay is the dominant source of photons and therefore measure the cross section for inclusive π0 production to be σ(π0)=(31.5±2.6) mb. Comparison with the inclusive π+ and π− cross sections at 12.0 GeV/c shows that the relation 2σ(π0)=σ(π+)+σ(π−) is well satisfied. We confirm earlier indications that the average number of π0's per inelastic pp interaction is approximately independent of the number of associated charged particles produced.

1 data table
Table 1

Axis error includes +- 8/8 contribution (THE CROSS SECTION FOR NON-PI0 GAMMA PRODUCTION IS LESS THAN 2.3 MB AND HAS BEEN NEGLECTED IN OBTAINING THE 31.5+-2.6 MB CROSS SECTION FOR THE INCLUSIVE PI0 PRODUCTION).


Inclusive $\pi^-$ Distributions from 205-GeV/c $pp$ Interactions.

Cho, Y. ; Engelmann, R. ; Fields, T. ; et al.
Phys.Rev.Lett. 31 (1973) 413-416, 1973.
Inspire Record 81713 DOI 10.17182/hepdata.21358

Inclusive π− distributions from 205-GeV/c pp interactions, covering the full range of longitudinal and transverse momenta, have been obtained using the 30-in. hydrogen bubble chamber at the National Accelerator Laboratory. These data provide new evidence for scaling in the fragmentation region and for a plateau in the central region of rapidity. The 90°-c.m. invariant cross section varies as exp[−(10±2)PT2] in the range PT2<~0.1 (GeV/c)2.

1 data table
Table 1

No description provided.


THE REACTION pi+ n ---> p omega AT 13-GeV/c

Paler, K. ; Tebes, J. ; Badewitz, R.C. ; et al.
Lett.Nuovo Cim. 4 (1972) 745, 1972.
Inspire Record 74599 DOI 10.17182/hepdata.37350

None

3 data tables
Table 1

SIMPLE BREIT-WIGNER FIT WITH ESTIMATED BACKGROUND OF 26 +- 8 PCT.

Table 2

MEASURED OFF GRAPH. BACKGROUND NOT SUBTRACTED. NOT CORRECTED FOR SMALL -T PAULI EXCLUSION EFFECTS (NEGLIGIBLE COMPARED WITH STATISTICAL ERRORS).

Table 3

No description provided.