HEPData Search

We have analyzed 2560 events in the final-state K O 1 K O 1 n produced in π − p interactions at 5, 7 and 12 GeV/ c . We observe the S ∗ (1070), f O and A 2 decaying into K O 1 K O 1 . Resonance parameters, cross sections, and branching ratios are given.

1 data table

Table 1

Cross section times branching ratio.

Experimental study study of antiproton-proton annihilation into a pair of charged Pi-Mesons or K-Mesons for incident antiproton mementa in the range from 0.72 GeV/c to 2.62 GeV/c

Fong, Douglas G. ; Pine, Jerome ;

RX-294, 1968.

Inspire Record 53368 DOI 10.17182/hepdata.50355

The cross sections for the two antiproton-proton annihilation-in-flight modes, ˉp + p → π+ + π- ˉp + p → k+ + k- were measured for fifteen laboratory antiproton beam momenta ranging from 0.72 to 2.62 GeV/c. No magnets were used to determine the charges in the final state. As a result, the angular distributions were obtained in the form [dσ/dΩ (ΘC.M.) + dσ/dΩ (π – ΘC.M.)] for 45 ≲ ΘC.M. ≲ 135°. A hodoscope-counter system was used to discriminate against events with final states having more than two particles and antiproton-proton elastic scattering events. One spark chamber was used to record the track of each of the two charged final particles. A total of about 40,000 pictures were taken. The events were analyzed by measuring the laboratory angle of the track in each chamber. The value of the square of the mass of the final particles was calculated for each event assuming the reaction ˉp + p → a pair of particles with equal masses. About 20,000 events were found to be either annihilation into π ±-pair or k ±-pair events. The two different charged meson pair modes were also distinctly separated. The average differential cross section of ˉp + p → π+ + π- varied from ~ 25 µb/sr at antiproton beam momentum 0.72 GeV/c (total energy in center-of-mass system, √s = 2.0 GeV) to ~ 2 µb/sr at beam momentum 2.62 GeV/c (√s = 2.64 GeV). The most striking feature in the angular distribution was a peak at ΘC.M. = 90° (cos ΘC.M. = 0) which increased with √s and reached a maximum at √s ~ 2.1 GeV (beam momentum ~ 1.1 GeV/c). Then it diminished and seemed to disappear completely at √s ~ 2.5 GeV (beam momentum ~ 2.13 GeV/c). A valley in the angular distribution occurred at cos ΘC.M. ≈ 0.4. The differential cross section then increased as cos ΘC.M. approached 1. The average differential cross section for ˉp + p → k+ + k- was about one third of that of the π±-pair mode throughout the energy range of this experiment. At the lower energies, the angular distribution, unlike that of the π±-pair mode, was quite isotropic. However, a peak at ΘC.M. = 90° seemed to develop at √s ~ 2.37 GeV (antiproton beam momentum ~ 1.82 GeV/c). No observable change was seen at that energy in the π±-pair cross section. The possible connection of these features with the observed meson resonances at 2.2 GeV and 2.38 GeV, and its implications, were discussed.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Study of the phi meson production with the orsay electron-positron colliding beams

Augustin, J.E. ; Bizot, J.C. ; Buon, J. ; et al.

Phys.Lett.B 28 (1969) 517-520, 1969.

Inspire Record 56680 DOI 10.17182/hepdata.6179

We have measured the e + e − → φ reaction by the K S 0 K L 0 and 3 π decay modes of the φ. We have deduced Γ ( φ → all), Γ ( φ →e + e − ), as well as B ( φ →K S 0 K L 0 ), B ( φ →K + K − ) and B ( φ → π + π − π 0 ).

3 data tables

Table 1

No description provided.

Table 2

RESONANCE FIT TO 12 DATA POINTS AROUND PHI FOR EACH CHANNEL GIVES PHI WIDTH OF 4.2 +- 0.9 MEV AND BR(PHI --> PI+ PI0 PI-/PHI --> KL KS) OF 0.667 +- 0.157 (RATHER HIGH).

Table 3

No description provided.

Kp and pi-p backward elastic scattering at 5.2 and 6.9 gev/c

Baker, W.F. ; Berkelman, Karl ; Carlson, P.J. ; et al.

Phys.Lett.B 28 (1968) 291-295, 1968.

Inspire Record 56828 DOI 10.17182/hepdata.29075

The angular distributions of K + p and π + p backward elastic scattering have been measured at 5.2 and 6.9 GeV/ c . Backward π - p and K - p elastic scattering were studied at 6.9 GeV/ c . Backward peaks are observed in K + p scattering with an energy dependence of the form s −4 .

1 data table

Table 1

No description provided.

A study of the reaction pi-minus + p ---> lambda + anti-lambda + n at 7 and 12 gev/c

Beusch, W. ; Fischer, W.E. ; Pepin, M. ; et al.

Phys.Lett.B 28 (1968) 211-214, 1968.

Inspire Record 56830 DOI 10.17182/hepdata.29078

Over 100 unambiguous π − + p → Λ + Λ + n events have been observed in a magnet spark chamber. The data provide good evidence for peripheral production of Λ Λ and n Λ (via meson exchange) and against peripheral n Λ (double baryon exchange). No resonances in the Λ Λ system are observed. Angular distributions and Λ( Λ ) polarizations are analysed.

1 data table

Table 1

Axis error includes +- 0.0/0.0 contribution (?////Corrected for neutral decays, absorption).

PHOTOPRODUCTION OF K+ LAMBDA AND K+ SIGMA0 FROM HYDROGEN FROM 5-GeV to 16-Gev

Boyarski, A. ; Bulos, F. ; Busza, W. ; et al.

Phys.Rev.Lett. 22 (1969) 1131-1133, 1969.

Inspire Record 54849 DOI 10.17182/hepdata.3394

Cross sections for the reactions γp→K+Λ and γp→K+Σ0 have been measured at squared four-momentum transfer (−t) from 0.005 to 2 GeV2, at photon energies 5, 8, 11, and 16 GeV. For −t>0.2 GeV2 each of the K+ cross sections is about ⅓ of the π+n photoproduction cross section, having nearly the same energy and momentum-transfer dependence. The K+ cross sections fall off at small |t|, however, in contrast to the sharp forward spike seen in π+n; this leads to a disagreement with an SU(3) prediction for −t<0.1 GeV2. The ratio of K+Σ0 to K+Λ cross sections is typically between 0.5 and 1.0.

9 data tables

Table 1

'1'.

Table 2

'1'.

Table 3

'1'.

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SINGLE pi+- AND K+ PHOTOPRODUCTION FROM COMPLEX NUCLEI AT 8-GeV AND 16-GeV

Boyarski, A. ; Diebold, Robert E. ; Ecklund, Stanley D. ; et al.

Phys.Rev.Lett. 23 (1969) 1343-1346, 1969.

Inspire Record 54879 DOI 10.17182/hepdata.21641

The reactions γA→π±A* have been studied at four-momentum transfers −t<~0.5 GeV2 for seven elements ranging from hydrogen to lead. Exclusion-principle suppression is clearly visible at small-momentum transfer. Neither the A dependence nor the energy dependence of the cross sections agrees with the predictions of the vector-dominance model. The ratio of π−π+ production requires equal spatial distributions for the protons and neutrons in nuclei. Some K+ data are also presented.

16 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.