A Study of pi- p --> f0 n Reaction at Momenta Up to 50-GeV/c

Bolotov, V.N. ; Isakov, V.V. ; Kakauridze, D.B. ; et al.
Phys.Lett.B 52 (1974) 489, 1974.
Inspire Record 90366 DOI 10.17182/hepdata.19110

A mass spectrum of π o π o system in the final state of π − p → π o π o n reaction has been studied at the momenta 20 to 50 GeV/ c . The experiments were performed at the 70 GeV IHEP accelerator. In the mass distribution there has been selected a peak corresponding to f o meson production cross section decreases in the power form with the momentum. The differential cross section follows exponential dependence, exp ( bt ).

5 data tables
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Measurement of pi- p --> pi0 pi0 n from threshold to p(pi-) 750-MeV/c.

The Crystal Ball collaboration Prakhov, S. ; Nefkens, B.M.K. ; Allgower, C.E. ; et al.
Phys.Rev.C 69 (2004) 045202, 2004.
Inspire Record 647544 DOI 10.17182/hepdata.25355

Reaction π−p→π0π0n has been measured with high statistics in the beam momentum range 270–750MeV∕c. The data were obtained using the Crystal Ball multiphoton spectrometer, which has 93% of 4π solid angle coverage. The dynamics of the π−p→π0π0n reaction and the dependence on the beam energy are displayed in total cross sections, Dalitz plots, invariant-mass spectra, and production angular distributions. Special attention is paid to the evaluation of the acceptance that is needed for the precision determination of the total cross section σt(π−p→π0π0n). The energy dependence of σt(π−p→π0π0n) shows a shoulder at the Roper resonance [i.e., the N(1440)12+], and there is also a maximum near the N(1520)32−. It illustrates the importance of these two resonances to the π0π0 production process. The Dalitz plots are highly nonuniform; they indicate that the π0π0n final state is dominantly produced via the π0Δ0(1232) intermediate state. The invariant-mass spectra differ much from the phase-space distributions. The production angular distributions are also different from the isotropic distribution, and their structure depends on the beam energy. For beam momenta above 550MeV∕c, the density distribution in the Dalitz plots strongly depends on the angle of the outgoing dipion system (or equivalently on the neutron angle). The role of the f0(600) meson (also known as the σ) in π0π0n production remains controversial.

5 data tables

Measured total cross section. Statistical errors only.

Differential angular distributions of the 2PI0 system for the LH2 data at beam momenta 355 to 472 MeV/c. Statistical errors only.

Differential angular distributions of the 2PI0 system for the LH2 data at beam momenta 550 to 678 MeV/c. Statistical errors only.

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OBSERVATION OF THE ASYMMETRY IN THE REACTION pi- p (polarized) ---> (pi0 pi0) n

Apokin, V.D. ; Belikov, N.I. ; Derevshchikov, A.A. ; et al.
Sov.J.Nucl.Phys. 47 (1988) 465, 1988.
Inspire Record 246899 DOI 10.17182/hepdata.40790

None

2 data tables

No description provided.

No description provided.


MEASUREMENT OF PI- P ---> PI0 PI0 N AT 25-GEV/C

Apel, W.D. ; Augenstein, K.H. ; Bertolucci, E. ; et al.
Nucl.Phys.B 201 (1982) 197-204, 1982.
Inspire Record 181089 DOI 10.17182/hepdata.17634

The reaction π − p→ π 0 π 0 n has been measured with a 648 channel hodoscope spectrometer for the detection of the four γ's from the π 0 decays. The π 0 π 0 D-wave is fully compatible with the f 0 contribution as it is determined in high-statistics π + π − experiments. The magnitude of the π 0 π 0 S-wave and the cosinus of its phase angle (relative to the known D-wave) are determined from fits to the π 0 π 0 angular distributions. Argand diagrams for the I = 0 amplitude S 0 are given for the range 1000 to 1500 MeV/ c 2 . Two solutions exist. One exceeds the unitarity limit above 1200 MeV/ c 2 . The other remains within the unitarity limit and is nearly elastic up to 1450 MeV/ c 2 . It indicates an S 0 wave resonance around 1300 MeV/ c 2 .

2 data tables

No description provided.

No description provided.


Observation of a Spin 6 Neutral Meson R (2510)

The Serpukhov-Brussels-Annecy(LAPP) collaboration Binon, F.G. ; Donskov, S.V. ; Duteil, P. ; et al.
Lett.Nuovo Cim. 39 (1984) 41, 1984.
Inspire Record 191410 DOI 10.17182/hepdata.37330

In a high-statistics experiment (200 events/nanobarn) performed at the 70 GeV IHEP accelerator, a new dipion resonance has been observed in π−p collisions at 38 GeV/c momentum. The gamma-rays in reaction π−p → M0n, M0 → π0π0 → 4γ have been detected in the hodoscope spectrometer GAMS-2000. The new meson, r(2510), has a mass (2510±30) MeV/c2, a width (240±60) MeV/c2 and spin-parityJPC=6++. The production cross-section of the f, h and r mesons decreases exponentially with spin like exp [−0.9J].

1 data table

No description provided.


The Investigation of the $\pi^- p \to \pi^0 \pi^0 n$ Reaction Near the Threshold

Belkov, A.A. ; Bunyatov, S.A. ; Zalikhanov, B.Zh. ; et al.
Sov.J.Nucl.Phys. 31 (1980) 96, 1980.
Inspire Record 142916 DOI 10.17182/hepdata.18169

None

2 data tables

FIRST VARIANT OF INSTALLATION.

SECOND VARIANT OF INSTALLATION.