Four-pion final state in anti-p p annihilations at 940 mev/c

Burns, R.R. ; Condon, P.E. ; Donahue, J. ; et al.
Nucl.Phys.B 27 (1971) 109-124, 1971.
Inspire Record 68769 DOI 10.17182/hepdata.33655

Resilts are reported on the four-pion final state from antiproton annihilations in hydrogen in the vicinity of 940 MeV/ c . The cross section for π − π − π + π + is found to be 3.6 mb. Abundant resonance production is observed, with fits indicating that quasi-two-body production constitutes approximately half the four-pion events. The model employed, which includes resonance production and Bose symmetrization, yields excellent fits to mass distributions and angular correlations.

2 data tables

ASSUMING TOTAL AP P CROSS SECTION OF 122 MB. ERRORS INCLUDE SYSTEMATIC UNCERTAINTIES.

ANALYSIS OF 4PION FINAL STATE. FIXED MASS AND WIDTH BREIT-WIGNER RESONANCES AND BACKGROUND FITTED TO DATA. CROSS SECTIONS CALCULATED BY PDG (COMPILATION PDG3). ERROR GIVEN IS SCATTER FROM VARIOUS FITS.


Absence of discrete s-channel resonances in anti-p p interactions at intermediate energies

Fields, T. ; Cooper, W.A. ; Rhines, D.S. ; et al.
Phys.Rev.Lett. 27 (1971) 1749-1752, 1971.
Inspire Record 75556 DOI 10.17182/hepdata.21475

We give new experimental results on ρω interference and two-body cross sections in p¯p annihilation at 2.3GeVc. These are used, together with ρω interference results from lower energies, to argue that the annihilation process is not mediated by discrete s-channel mesonic resonances in the mass range 2.1-2.6 GeV.

1 data table

No description provided.


Anti-p p Annihilations Into Four and Five Pion Final States in the t (2190) Region

Handler, T. ; Jacques, P. ; Jones, M. ; et al.
Nucl.Phys.B 101 (1975) 35, 1975.
Inspire Record 99552 DOI 10.17182/hepdata.36053

New data from a 600 000 picture exposure of the BNL 31 inch hydrogen bubble chamber to a separated antiproton beam have been analyzed to try to determine if the π + π − π + π − or π + π − π + π − π 0 final states contribute any broad or narrow structure in the T(2190) region. The resonance channel fractions determined by maximum likelihood fits are all consistent with smooth behavior through the T-region and therefore there is no significant evidence that any of these resonance channels contributes to the broad bump in the total cross section. The errors on some of the fractions, however, limit the sensitivity to ∼ 0.5 mb for enhancements in these channels.

2 data tables

RESONANCE CHANNEL PERCENTAGES FROM FIT TO PI+ PI- PI+ PI- FINAL STATE.

RESONANCE CHANNEL PERCENTAGES FROM FIT TO PI+ PI- PI+ PI- PI0 FINAL STATE.


Anti-p p annihilations into four charged mesons from 1.6 to 2.2 gev/c

Davidson, J. ; Chapman, J.W. ; Green, R.W. ; et al.
Phys.Rev.D 9 (1974) 77-90, 1974.
Inspire Record 93127 DOI 10.17182/hepdata.21951

The following reactions have been analyzed: (1) p¯p→π−π−π+π+; (2) p¯p→π−π+K−K+; (3) p¯p→K−K−K+K+. Cross sections as a function of beam momentum ranging from 1.6 to 2.2 GeVc are presented. The percentage of resonance production in reaction (1) is examined using the maximum-likelihood (ML) method. The channel is dominated by ρππ and ρf production. The percentage of ρf decreases with p¯ momentum, while ρππ appears to increase. ML fits are also made to reaction (2); the reaction is dominated by K*Kπ, ϕππ, and ρKK production. An enhancement is seen in the Q region of the ππK mass spectrum at 1278 MeV, with FWHM (full width at half maximum) of 25 MeV. Six events are consistent with reaction (3). Mass spectra indicate that five events have at least one ϕ meson produced; one of these is a ϕϕ event.

3 data tables

NORMALIZED TO KNOWN TOTAL CROSS SECTION.

'FIT 9'. ENERGY DEPENDENCE AND EFFECT OF BOSE-EINSTEIN STATISTICS ALSO STUDIED.

'FIT F'.


Study of a $K^0_S K^0_S$ Plus Threshold Enhancement Observed in the Final States $\bar{p} p \to K^0_S K^0_S$ Pions at 700-{MeV}/$c$ to 760-{MeV}/$c$

Aguilar-Benitez, M. ; Cerrada, M. ; Gonzalez-Arroyo, Antonio ; et al.
Nucl.Phys.B 140 (1978) 73-108, 1978.
Inspire Record 130239 DOI 10.17182/hepdata.25444

An analysis of the K 0 K 0 system at threshold produced in the final states p p → K S 0 K S 0 ( n π) at 700–760 MeV/ c , is presented. A simultaneous fit to the ππ phase shifts and inelasticities and to the K S 0 K S 0 effective-mass distributions using parametrizations which take into account the analytical and unitarity properties of the I = 0 S-wave amplitudes is performed. The behaviour of the eigenphases and the unphysical Riemann sheet structure for different solutions is studied.

3 data tables

No description provided.

FIT TO RESONANCE PRODUCTION CHANNELS IN <KS KS PI+ PI-> FINAL STATE.

FIT TO RESONANCE PRODUCTION CHANNELS IN <KS KS PI0> FINAL STATE.


A formation study of n anti-n interactions between 1.51 and 2.90 gev/c. iii. resonance production

Ming, Ma.Z. ; Eastman, P.S. ; Oh, B.Y. ; et al.
Nucl.Phys.B 51 (1973) 77-94, 1973.
Inspire Record 84298 DOI 10.17182/hepdata.32684

A systematic study of p p and p d resonance production cross sections in non-strange annihilation channels between 1.51 and 2.90 GeV/ c has been completed. The data have been analysed in relation to the three known structures at c.m. N N energies of 2190, 2350 and 2375 MeV. Several resonance intermediate states may have broad maxima near the isopin one 2350 MeV structure. However, more data below 1.6 GeV/ c are required to better describe the background in this region before firm conclusions may be drawn.

2 data tables

No description provided.

No description provided.