HEPData Search

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

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A-DEPENDENCE OF PI MESON CUMULATIVE PRODUCTION CROSS-SECTIONS IN PROTON NUCLEAR COLLISIONS. (IN RUSSIAN)

Bondarev, V.K. ; Zarubin, P.I. ; Litvinenko, A.G. ; et al.

Dubna Jinr - 84-N04A (84,REC.JAN.85) 4p, 1985.

Inspire Record 215608 DOI 10.17182/hepdata.38302

None

2 data tables

Table 1

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Table 2

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Evidence of the Cabibbo Suppressed Decay $\Lambda_c^+ \to p K^- K^+$

The E687 collaboration Frabetti, P.L. ; Cheung, H.W.K. ; Cumalat, John P. ; et al.

Phys.Lett.B 314 (1993) 477-481, 1993.

Inspire Record 356600 DOI 10.17182/hepdata.42675

We report evidence for the Cabibbo-suppressed decay of the charm baryon Λ c + into the final state pK − K + . The analysis is performed on data collected by high energy photoproduction experiment E687 during the 1990–1991 Fermilab fixed target run. The branching ratio of the decay Λ c + → pK − K + relative to the non-suppressed Λ c + → pK − π + is measured to be BR( pK − K + / pK − π + ) = 0.096 ± 0.029 ± 0.010. The upper limit of the decay into pø relative to the inclusive pK − K + decay is measured to be BR( pø / pK − K + < 58% at the 90% confidence level.

2 data tables

Table 1

Branching ratio of Cabibbo-suppressed and resolved modes.

Table 2

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Coupled channel analysis of anti-p p annihilation into pi0 pi0 pi0, pi0 eta eta and pi0 pi0 eta

The Crystal Barrel collaboration Amsler, C. ; Armstrong, D.S. ; Baker, C.A. ; et al.

Phys.Lett.B 355 (1995) 425-432, 1995.

Inspire Record 406130 DOI 10.17182/hepdata.28523

We confirm the existence of the two I G ( J PC ) = 0 + (0 ++ ) resonances f 0 (1370) and f 0 (1500) reported by us in earlier analyses. The analysis presented here couples the final states π 0 π 0 π 0 , π 0 π 0 η and π 0 ηη of p p annihilation at rest. It is based on a 3 × 3 K -matrix. We find masses and widths of M = (1390±30) MeV, Γ = (380±80) MeV; and M = (1500±10) MeV, Γ = (154 ± 30) MeV, respectively. The product branching ratios for the production and decay into π 0 π 0 and ηη of the f 0 (1500) are (1.27 ± 0.33) · 10 −3 and (0.60 ± 0.17) · 10 −3 , respectively.

1 data table

Table 1

No description provided.

Observation of radiative anti-p p annihilation into a phi meson

The Crystal Barrel collaboration Amsler, C. ; Armstrong, D.S. ; Augustin, I. ; et al.

Phys.Lett.B 346 (1995) 363-370, 1995.

Inspire Record 401140 DOI 10.17182/hepdata.28709

The annihilation p p → Φγ has been investigated with the Crystal Barrel detector at LEAR for antiprotons stopped in liquid hydrogen. The observed branching ratio BR ( p p → Φγ = (1.7 ± 0.4) · 10 −5 is almost two orders of magnitude higher than expected from the OZI-rule. As a by-product, the branching ratios BR ( p p → K L K S ) = (9.0 ± 0.6) · 10 −4 and BR ( p p → Φπ 0 ) = (5.5 ± 0.7) · 10 −4 have been measured.

1 data table

Table 1

No description provided.

First observation of the production of nucleon resonances in anti-proton annihilation in liquid deuterium

The Crystal Barrel collaboration Amsler, C. ; Armstrong, D.S. ; Augustin, I. ; et al.

Phys.Lett.B 352 (1995) 187-192, 1995.

Inspire Record 405540 DOI 10.17182/hepdata.28705

None

1 data table

Table 1

No description provided.

E decay to eta pi pi in anti-p p annihilation at rest

The Crystal Barrel collaboration Amsler, C. ; Armstrong, D.S. ; Baker, C.A. ; et al.

Phys.Lett.B 358 (1995) 389-398, 1995.

Inspire Record 407517 DOI 10.17182/hepdata.28511

We have observed the ηπ + π − and ηπ 0 π 0 decay modes of the E meson in p p annihilation at rest into π + π − π 0 π 0 η . The mass and width of the E meson are 1409 ± 3 and 86 ± 10 MeV. The production and decay branching ratio is B( p p → Eππ)B(E → ηππ) = (3.3 ± 1.0) × 10 −3 . With a spin-parity analysis we determine that J P = 0 − . The observation of the ηπ 0 π 0 decay mode establishes that E is isoscalar ( C = +1). We find that E decays to η ( ππ ) s (where ( ππ ) s is an S-wave dipion) and πa 0 (980)(→ πη ) with a relative branching ratio of (78 ± 16) %. Using the K K π production and decay branching ratio measured earlier we determine that B[E → K K π] B[E → ηππ] = 0.61 ± 0.19 . A comparison with observations in radiative J Ψ decays suggests that E and ι η (1416) are identical.

1 data table

Table 1

Unobserved channels (E --> ETA 2PI0)2PI0 and (E --> ETA PI+ PI-)PI+PI- was taken into account.

Measurement of J / psi, psi-prime and upsilon total cross-sections in 800-GeV/c p - Si interactions

The E771 collaboration Alexopoulos, T ; Antoniazzi, L ; Arenton, M ; et al.

Phys.Lett.B 374 (1996) 271-276, 1996.

Inspire Record 400873 DOI 10.17182/hepdata.42316

We report on the analysis of Charmonium and Bottomium states produced in p-Si interactions at s =38.7 GeV . The data have been collected with the open geometry spectrometer of the E771 Experiment at the FNAL High Intensity Lab. J ψ , ψ′ and γ total cross sections as well as the ratio B(ψ′ → μμ)σ(ψ′) (B( J ψ → μμ)σ( J ψ )) have been measured. Results are compared with theoretical predictions and with results at other energies.

3 data tables

Table 1

The total inclusive cross section per nucleon has been evaluated assuming an atomic weight dependence of A**POWER with POWER = 0.920 +- 0.008.

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combined UPSI(1S) and UPSI(2S) cross section.

Table 3

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Further study of the quasi-exclusive reactions of the neutral mesons production by 70-GeV protons in p N interactions in the deep fragmentation region. (Revised version, in Russian)

The SPHINX collaboration Vavilov, D.V. ; Viktorov, V.A. ; Golovkin, S.V. ; et al.

IFVE-95-138, 1995.

Inspire Record 406502 DOI 10.17182/hepdata.40645

None

2 data tables

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

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

A-DEPENDENCE OF PI MESON CUMULATIVE PRODUCTION CROSS-SECTIONS IN PROTON NUCLEAR COLLISIONS. (IN RUSSIAN)

Evidence of the Cabibbo Suppressed Decay $\Lambda_c^+ \to p K^- K^+$

Coupled channel analysis of anti-p p annihilation into pi0 pi0 pi0, pi0 eta eta and pi0 pi0 eta

Observation of radiative anti-p p annihilation into a phi meson

First observation of the production of nucleon resonances in anti-proton annihilation in liquid deuterium

E decay to eta pi pi in anti-p p annihilation at rest

Measurement of J / psi, psi-prime and upsilon total cross-sections in 800-GeV/c p - Si interactions

Further study of the quasi-exclusive reactions of the neutral mesons production by 70-GeV protons in p N interactions in the deep fragmentation region. (Revised version, in Russian)