HEPData Search

Showing 10 of 225 results

Measurement of the production of high mass gamma gamma, pi0 pi0, and gamma pi0 pairs in pi- p, pi+ p, and p p collisions at 300-GeV/c

De Marzo, C. ; De Palma, M. ; Favuzzi, C. ; et al.

Phys.Rev.D 42 (1990) 748-758, 1990.

Inspire Record 303958 DOI 10.17182/hepdata.22851

The NA24 experiment at CERN investigated inclusive γγ, π0π0, and γπ0 final states in the mass range between 4 and 9 GeV/c2 produced in π−p, π+p, and pp reactions at a c.m.-system energy s=23.7 GeV. The π0π0 cross sections agree well with expectations of the quark-parton model. For γπ0 production in π−p and pp reactions, a clear signal is observed and cross sections are shown. The production of γγ events was observed with a statistical significance of 2.9σ in π−p reactions. The cross section is in agreement with a higher-order QCD prediction.

5 data tables

Table 1

Cross sections are averaged over the transverse momentum differences up to a value which is 1.10 GeV for all points except the first two which are 0.5 and 0.75 GeV respectively.

Table 2

No description provided.

Table 3

Maximum accepted transverse momentum difference of pi0 pair is 1 GeV. Inclusive cross section integrated over the total geometrical acceptance of the detector.

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Vector Meson Production in $\pi^- p$ Interactions at 360-{GeV}/$c$

The LEBC-EHS collaboration Aguilar-Benitez, M. ; Bailly, J.L. ; Batalov, A.A. ; et al.

Z.Phys.C 44 (1989) 531, 1989.

Inspire Record 278763 DOI 10.17182/hepdata.15359

The inclusive production of vector mesons (charged ρ(770), ω(783), ϕ(1020) and neutralK*(892)) in π−p interactions at 360 GeV/c is studied. The data are based on 160 000 reconstructed events recorded in the NA 27 Experiment using the LEBC-EHS facility at CERN. The production cross sections in the forward hemisphere in c.m.s. and the longitudinal momentum distributions are determined. The results are compared with data obtained at lower energies.

17 data tables

Table 1

No description provided.

Table 2

Upper limits of cross sections.

Table 3

Cross sections extrapolated to x > 0.

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Study of rho0 and f2 meson production in pi- p interactions at 360-GeV/c

The NA27 LEBC/EHS collaboration Verbeure, F. ; De Roeck, A. ; Knauss, D. ; et al.

Sov.J.Nucl.Phys. 49 (1989) 631-635, 1989.

Inspire Record 292952 DOI 10.17182/hepdata.17327

None

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Inclusive Photoproduction of Single Charged Particles at High $p_T$

The OMEGA Photon collaboration Apsimon, R.J. ; Atkinson, M. ; Baake, M. ; et al.

Z.Phys.C 43 (1989) 63, 1989.

Inspire Record 276890 DOI 10.17182/hepdata.15435

Single charged-particle inclusive cross sections for photon, pion and kaon beams on hydrogen at the CERN-SPS are presented as functions ofpT andxF. Data cover the range 0.01.6 GeV/c for the photon-induced data. Using the hadron-induced data to estimate the hadronic behaviour of the photon, the difference distributions and ratios of cross sections are a measure of the contribution of the point-like photon interactions. The data are compared with QCD calculations and show broadly similar features.

4 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Recoil Proton Polarization in $\pi P$ Elastic Scattering at 547-{MeV}/c and 625-{MeV}/c

Seftor, C.J. ; Adrian, S.D. ; Briscoe, W.J. ; et al.

Phys.Rev.D 39 (1989) 2457-2463, 1989.

Inspire Record 282265 DOI 10.17182/hepdata.23234

The polarization of the recoil proton in π+p and π−p elastic scattering using a liquid-hydrogen target has been measured for backward angles at 547 and 625 MeV/c. The scattered pion and recoil proton were detected in coincidence using the large-acceptance spectrometer to detect and analyze the momentum of the pions and the JANUS polarimeter to identify and measure the polarization of the protons. Results from this experiment agree with other measurements of the recoil polarization, with analyzing-power data previously taken by this group, and with predictions of partial-wave analyses.

4 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

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Evidence for a 1.9-{GeV} Meson Decaying Into $\eta \eta^\prime$

The IFVE-Brussels-Annecy-Los Alamos collaboration Alde, D. ; Binon, F.G. ; Bricman, C. ; et al.

Phys.Lett.B 216 (1989) 447, 1989.

Inspire Record 267048 DOI 10.17182/hepdata.29856

Evidence for a new meson decaying into ηη′ has been found in 38 GeV π − p charge-exchange interactions. The mass and the width of this meson are (1917 ± 15) MeV and (90 −50 +35 ) MeV, respectively. Possible spin and parity assignments are J PC = 0 ++ , 1 −+ or 2 ++ , isospin and G -parity are I G = 0 + . The t -dependence of the differential cross section follows an exponential behaviour exp( bt with a small slope: b = (2±1) (GeV/ c ) −2 .Upper limits on its decay into ππ, ηη and K K exotic interpretation of this meson.

1 data table

Table 1

No description provided.

Study of $\omega \omega$ Systems Produced in 38-{GeV}/$c \pi^- p$ Collisions

The IHEP-IISN-LANL-LAPP-TSUIHEP collaboration Alde, D. ; Binon, F.G. ; Bricman, C. ; et al.

Phys.Lett.B 216 (1989) 451, 1989.

Inspire Record 267049 DOI 10.17182/hepdata.29857

The π − p→ ωω n reaction has studied for the first time at the 70 GeV IHEP accelerator. The six photons from the decay of the two ω mesons were detected in GAMS-2000, a hodoscope multi-photon spectometer. Two resonances decaying into ωω,X (1640) and X(1960), have been observed. Their quantum numbers are J PC =2 ++ , I G =0 + . The reaction is dominated by the one-pion exchange mechanism. The production cross sections σ. BR(X→ ωω ) are 0.65±0.15 μ b and 1.0±0.2 μ b, respectively.

2 data tables

Table 1

X(1640) IS A JPC - 2++, IG - 0+ MESON WITH MASS 1643+-7 MEV.

Table 2

X(1960) IS A JPC - 2++, IG - 0+ MESON WITH MASS 1956+-20 MEV.

OBSERVATION OF AN EXOTIC MESON OF 1.9-GeV MASS DECAYING INTO eta-prime eta

The IFVE-Brussels-Annecy-Los-Alamos collaboration Alde, D. ; Binon, F.G. ; Bricman, C. ; et al.

Sov.J.Nucl.Phys. 48 (1988) 1035, 1988.

Inspire Record 264474 DOI 10.17182/hepdata.40730

None

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Vector Resonances Around 1.6-{GeV} of the $\eta \pi^+ \pi^-$ System in the $\pi^- p$ Charge Exchange Reaction at 8.95-{GeV}/$c$

Fukui, S. ; Horikawa, N. ; Inaba, S. ; et al.

Phys.Lett.B 202 (1988) 441-446, 1988.

Inspire Record 261402 DOI 10.17182/hepdata.29989

High statistics data of the ηππ system in π − p → ηπ + π − n were obtained. A partial wave analysis was performed in the mass region between 1.37 and 1.85 GeV. Resonant structures were observed in the IJ PC = 11 −− wave around 1.6 GeV and in 13 −− around 1.7 GeV. The structure in 11 −− was fitted with a single Breit-Wigner and also fitted with two Breit-Wigner's. The result suggests the possible existence of two vector resonances around 1.6 GeV. The structure in 13 −− is considered to be the π 3 (1690).

3 data tables

Table 1

Result of single Breit Wigner fit around 1.6 GeV. Called here $M(1635).

Table 2

Results of double Breit Wigner fit around 1.6 GeV. $M(1446) and $M(1701).

Table 3

Result of Breit Wigner fit around 1.7 GeV.