Date

Experimental Proof of the Existence of the A1 Meson

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Phys.Lett.B 89 (1980) 281-284, 1980.
Inspire Record 143044 DOI 10.17182/hepdata.27272

In partial wave analyses of the ( π − π − π + ) system, substantial shape changes of the 1 + S ( ϱπ ) intensity as a function of t , and relative phase changes of ≈ 90°, provide compelling evidence for a resonant A 1 of mass ≈ 1280 MeV and width ≈ 300 MeV.

1 data table

No description provided.


3 $\pi$ Resonances in 2- Partial Waves

The ACCMOR collaboration Daum, C. ; Hertzberger, L. ; Hoogland, W. ; et al.
Phys.Lett.B 89 (1980) 285-289, 1980.
Inspire Record 143045 DOI 10.17182/hepdata.27275

The J PC = 2 −+ partial wave intensities and their large phase changes prove the resonant nature of the A 3 meson (mass ≈ 1670 MeV, width ≈ 210 MeV). The decay modes are f 0 π , ϱ 0 π , and ϵ 0 π . Evidence is found for a further 2 − enhancement.

1 data table

No description provided.


Measurement of $\pi^{\pm}$p Backward Elastic Scattering Between 30 and 90 GeV/c

Baker, W.F. ; Eartly, David P. ; Kalbach, R.M. ; et al.
Phys.Rev.Lett. 43 (1979) 1635, 1979.
Inspire Record 141766 DOI 10.17182/hepdata.20758

Measurements of π±p backward elastic scattering have been made for incident pion momenta between 30 and 90 GeV/c and for 0<−u<0.5 (GeV/c)2. The momentum dependence of the cross sections is of a form expected from a simple Regge model, and the u dependence of the cross sections is similar to that observed at lower momenta.

9 data tables

No description provided.

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PRODUCTION OF PHOTONS ASSOCIATED WITH THE PSI BY 217-GEV/C PI- MESONS

Kirk, T.B.W. ; Raja, R. ; Goodman, M. ; et al.
Phys.Rev.Lett. 42 (1979) 619-622, 1979.
Inspire Record 145303 DOI 10.17182/hepdata.20780

Dimuon production is studied in 217-GeV/c π−-hydrogen and π−-beryllium collisions with a lead-glass array to detect photons associated with the ψ. The ψ−γ mass spectrum shows a 2.6-standard-deviation excess of events above background at ∼3.5 GeV. This excess, if attributed to the decay χ(∼3.5)→ψγ, implies that 0.70±0.28 of the ψ's are produced via radiative decay of one of the χ states.

2 data tables

E*D(SIG)/D(XL) is fitted by (1-X)**POWER.

No description provided.


Neutron-Proton Forward Angle Elastic Cross-Sections at 790-MeV

Carlini, R. ; Dieterle, B. ; Donahue, J. ; et al.
Phys.Rev.Lett. 41 (1978) 1341-1344, 1978.
Inspire Record 136558 DOI 10.17182/hepdata.20861

High-statistics measurements of the absolute differential cross section for n−p scattering have been made over neutron c.m.-system scattering angles 9.5°<θ*<64.5°. The statistical error is 1.7 to 3.3% for 2°-wide angular bins, and the systematic error is 2.7 to 3.3%. The cross section is fitted by dσdΩ*=A exp(bt), with A=10.27±0.36 mb/sr, b=5.00±0.05, and 0.01<−t<0.39 (GeV/c)2. For the ratio of the real to the imaginary part of the forward-scattering amplitude we obtained αn>~−0.43±0.04, consistent with other less precise determinations of αn.

1 data table

EXPONENTIAL FIT TO D(SIG)/DOMEGA OVER -T = 0.01 TO 0.39 GEV**2 (THETA = 9.5 TO 64.5 DEG).


BACKWARD omega0 AND eta0 PRODUCTION IN pi p INTERACTIONS AT 9-GeV/c AND 12-GeV/c

Benkheiri, P. ; Eisenstein, Bob I. ; Fleury, P. ; et al.
Nucl.Phys.B 150 (1979) 268-286, 1979.
Inspire Record 132166 DOI 10.17182/hepdata.34809

We have studied the backward production of ω 0 mesons in the u -channel I u = 1 2 exchange reaction π − p → N 0 (1680) ω 0 at 9 GeV/ c and 12 GeV/ c incident momenta. The data come from an experiment performed at the CERN Omega Spectrometer using a fast proton trigger device. The backward production of the η 0 meson has also been observed and the coupling constant ratio g η NN / g π NN has been estimated.

3 data tables

No description provided.

No description provided.

JACKSON FRAME (U-CHANNEL HELICITY SYSTEM).


Backward Production of the $B$ Meson in $K^- p$ Interactions at 4.2-{GeV}/$c$

The Amsterdam-CERN-Nijmegen-Oxford collaboration Gavillet, P. ; Dionisi, C. ; Gurtu, A. ; et al.
Phys.Lett.B 78 (1978) 158-161, 1978.
Inspire Record 131673 DOI 10.17182/hepdata.27430

The backward production of the B(1235) meson is studied in the reaction K − p → Σ − π + ω . This reaction is observed in the final state Σ − π + π + π − π 0 . A π + ω mass enhancement is visible in the region of the B meson for events with small | u |K − → Σ − ) squared four-momentum transfer. The properties of the enhancement agree with those of the B meson. The cross section for K − p → Σ − B + at 4.15 GeV c incident K − momentum is (3.2 ± 0.5) μb . The backward production of the B meson is compared with similar baryon exchange productions of the A 1 and C(Q 1 ) axial vector mesons observed in the same experiment.

2 data tables

No description provided.

No description provided.


Observation of the $D$, $e$ and Delta Mesons in $\pi^- p$ Interactions at 12-{GeV}/$c$ and 15-{GeV}/$c$

Corden, M.J. ; Dowell, J.D. ; Garvey, J. ; et al.
Nucl.Phys.B 144 (1978) 253-268, 1978.
Inspire Record 131142 DOI 10.17182/hepdata.22222

We have observed the D(1285), E(1420) and δ(975) mesons produced in 12 and 15 GeV/ c π − p interactions at the CERN Omega Spectrometer. Production cross sections and decay branching ratios are presented. Analysis of the decay D(1285) → δ (975) π favours a spin-parity assignment of 1 + .

3 data tables

No description provided.

CORRECTED FOR DECAY MODES OTHER THAN <ETA PI+ PI-> AND FOR THE UNOBSERVED PARTS OF THE T-DISTRIBUTION.

No description provided.


Production of Multi - Pion Systems With Large Longitudinal Momentum at the {CERN} {ISR}

Lockman, William S. ; Meyer, T. ; Rander, J. ; et al.
Phys.Rev.Lett. 41 (1978) 680-683, 1978.
Inspire Record 6695 DOI 10.17182/hepdata.20814

Inclusive cross sections are presented for 2π and 3π systems with large longitudinal x at the highest intersecting storage ring energies (s=53 GeV for 2π; s=53 and 62 GeV for 3π). The ratio π+π−π−π− rises sharply with increasing x similar to the ratio K+K−, as expected in a quark-model interpretation.

2 data tables

The differential cross section is fitted by the equation : E*D3(SIG)/D3(P) = CONST*(1-XL)**POWER*EXP(-SLOPE*PT**2).

The differential cross section is fitted by the equation : E*D3(SIG)/D3(P) = CONST*(1-XL)**POWER*EXP(-SLOPE*PT**2).


Backward Production of a Spin Parity 1+ $K \rho$ Resonance at 1.28-{GeV}

The Amsterdam-CERN-Nijmegen-Oxford collaboration Gavillet, P. ; Diaz, J. ; Dionisi, C. ; et al.
Phys.Lett.B 76 (1978) 517-522, 1978.
Inspire Record 130237 DOI 10.17182/hepdata.27442

A ( K π π ) + mass enhancement is observed in the reactions K − p → Ξ −K o + π + π o − when events with a small (K − → Ξ − ) four momentum transfer squared are selected. The signal is also visible in the reaction K − p → Ξ − π + + neutrals. The enhancement, centered at 1.28 GeV, is seen to decay preferentially into Kϱ with spin-parity J P = 1 + . The cross section for K − p→ Ξ − C + (1.28) with C + → K ϱ at 4.15 GeV/c incident K − momentum is (6.2 ± 0.6) μ b.

1 data table

ASSUMING ISOSPIN HALF FOR C(1280)+ AND C(1400)+. FOR C(1280)+, D(SIG)/DU HAS SLOPE OF 1.60 +- 0.30 GEV**-2. THESE AXIAL VECTOR RESONANCES ARE HERE ENCODED AS QLOW(1240)+ AND QHIGH(1340)+.