X0 ---> 2gamma from pi- p ---> neutral meson + neutron at 3.8 gev/c

Apel, W.D. ; Auslaender, J. ; Mueller, H. ; et al.
Phys.Lett.B 40 (1972) 680-684, 1972.
Inspire Record 75664 DOI 10.17182/hepdata.28261

We report on a measurement for the branching-ratio X 0 → 2γ X 0 ar all. Our result is X 0 → 2γ X 0 → all = (2.9 ± 0.9)% .

1 data table

BY COMPARISON WITH THE KNOWN ETA PRODUCTION CROSS SECTION.


Results on the production cross-sections pi- p ---> neutrals and pi- p ---> chi0(2gamma) n at 3.8, 6, 8 and 12 gev/c

Apel, W.D. ; Auslaender, J. ; Mueller, H. ; et al.
Phys.Lett.B 46 (1973) 459-464, 1973.
Inspire Record 95163 DOI 10.17182/hepdata.28058

The ratio between the cross sections for the reactions π − p→ χ ↳ 2γ 0 n and π − p → η →2 γ n has been measured to be (2.4 ± 0.9) × 10 −2 , (2.1 ± 0.6) × 10 −2 and (2.8 ± 1.3) × 10 −2 at 3.8,6,8 and 12 GeV/ c incident momentum respectively.

1 data table

ETAPRIME CROSS SECTIONS DEDUCED FROM THEIR RATIO TO ETA PRODUCTION, USING THE RESULTS OF O. GUISAN ET AL., PL 18, 200 (1965).


Reaction pi- p ---> x0 n, x0 ---> 2 gamma at Momenta 15-GeV/c and 40-GeV/c

The Serpukhov-CERN collaboration Apel, W.D. ; Bertolucci, Ennio ; Donskov, S V ; et al.
Sov.J.Nucl.Phys. 25 (1977) 300, 1977.
Inspire Record 91260 DOI 10.17182/hepdata.19034

None

2 data tables

No description provided.

No description provided.


Investigation of the reaction pi- p ---> eta n at momenta up to 40-GeV/c

The Serpukhov-CERN collaboration Apel, W.D. ; Bertolucci, E. ; Bushnin, Yu.B. ; et al.
Sov.J.Nucl.Phys. 25 (1977) 194-197, 1977.
Inspire Record 118649 DOI 10.17182/hepdata.19079

None

2 data tables

No description provided.

No description provided.


Reaction pi- p --> eta n at Large Momentum Transfer

The Serpukhov-CERN collaboration Apel, W.D. ; Augenstein, K. ; Bertolucci, E. ; et al.
Sov.J.Nucl.Phys. 27 (1978) 82-83, 1978.
Inspire Record 119329 DOI 10.17182/hepdata.11051

None

3 data tables

No description provided.

No description provided.

No description provided.


Observation of A Meson x --> 2 gamma, with Mass 2.85-GeV/c**2, Produced in the Charge Exchange Reaction pi- p --> x n at 40-GeV/c

Apel, W.D. ; Augenstein, K.H. ; Bertolucci, E. ; et al.
Phys.Lett.B 72 (1978) 500-502, 1978.
Inspire Record 122151 DOI 10.17182/hepdata.27481

The invariant mass spectrum of neutral final states produced in π − p charge-exchange scattering at 40 GeV/ c has been studied, searching for heavy particles decaying in 2γ. A peak is observed around 2.85 GeV/ c 2 . The cross section of the reaction π − p→X(2.85)+n, times the branching ratio of the X→2 γ decay, is measured to be σ × BR ⋍ 2 × 10 −34 cm 2 .

1 data table

MEAN VALUE OF -T = 0.28 +- 0.04 GEV**2.


Production of x (2.85) Particles in Charge Exchange Reaction pi- p --> Chi n, Chi --> 2 gamma at 40-GeV/c

The Serpukhov-CERN collaboration Apel, W.D. ; Augenstein, K. ; Bertolucci, E. ; et al.
Sov.J.Nucl.Phys. 27 (1978) 524, 1978.
Inspire Record 122184 DOI 10.17182/hepdata.19014

None

1 data table

No description provided.


Experimental Confirmation of the 1100 Structure and First Observation of the Leptonic Decay of the $\rho^\prime$ (1250)

Bartalucci, S. ; Basini, G. ; Bertolucci, S. ; et al.
Nuovo Cim.A 49 (1979) 207, 1979.
Inspire Record 131639 DOI 10.17182/hepdata.37533

We have extended our survey of the reaction γ+p→p+e++e− by collecting 20 000 additional e+e− pairs in the invariant-mass region 900<m<1500 MeV. The measured interference pattern shows two enhancements at mass values of 1097 and 1266 MeV. The parameters of those structure, when interpreted as vector mesons in the VDM framework, are given.

1 data table

No description provided.


Reaction $\pi^- p \to \eta n$ in the 15-{GeV}/$c$ to 40-{GeV}/$c$ Momentum Range

The Serpukhov-CERN collaboration Apel, W.D. ; Augenstein, K.H. ; Bertolucci, E. ; et al.
Nucl.Phys.B 152 (1979) 1, 1979.
Inspire Record 133409 DOI 10.17182/hepdata.41487

A high-statistics measurement of the reaction π − p→ η n; η →2 γ has been performed at the 70 GeV Serpukhov accelerator for 15, 20, 25, 30 and 40 GeV/ c incident pion momentum using the NICE set-up with its associated 648-channel hodoscope spectrometer for γ-ray detection. It is found that the spin-flip and non-spin-flip amplitudes can be parametrized, for small | t |, as exponentials with the same slopes to within a few percent. For | t | ≳ 1 (GeV/ c ) 2 there is a break in the differential cross section. In addition, the A 2 effective trajectory deviates markedly for | t | ≳ 1 GeV/ c ) 2 from the linear behaviour valid for smaller | t |.

4 data tables

No description provided.

No description provided.

No description provided.

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Reaction $\pi^- p \to \eta^\prime n$ in the 15-{GeV}/$c$ - 40-{GeV}/$c$ Momentum Range

The Serpukhov-CERN collaboration Apel, W.D. ; Augenstein, K.H. ; Bertolucci, E. ; et al.
Phys.Lett.B 83 (1979) 131, 1979.
Inspire Record 141023 DOI 10.17182/hepdata.49657

Measurements were made of the cross section of the reactions π − p → ν ′(958)n, η ′ → 2 γ at momenta at 15, 20, 25, 30 and 40 GeV/c. The experiment was carried out on the IHEP 70 GeV accelerator using the 648 channel hodoscope spectrometer NICE for γ-ray detection. A total of 6000 η′ mesons were recorded. A sharp drop is seen in the differential cross section for t → 0. The dependences of the differential cross sections for the π − p → η ′n and π − p → η n on t are identical. On the basis of the ratio of the cross sections for these reactions at t = 0, i.e. R( η′ n ) t=0 = 0.55 ± 0.06 , the singlet-octet mixing angle for pseudoscalar mesons was determined to be β = −(18.2 ± 1.4)°.

8 data tables

AVERAGE RATIO IS 2.76 +- 0.07 PCT.

AVERAGE RATIO IS 0.52 +- 0.02.

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