Further evidence for the decay mode phi ---> eta gamma and measurement of the branching ratio gamma(phi ---> eta gamma)/gamma(phi ---> total)

Basile, M. ; Dalpiaz, P. ; Frabetti, P.L. ; et al.
Nucl.Phys.B 44 (1972) 605-617, 1972.
Inspire Record 75023 DOI 10.17182/hepdata.32854

The reaction π − p → ηφ has been studied at 1.8 GeV/ c incident pion momentum using the Bologna-CERN NBC set-up, in order to investigate the electromagnetic decay mode φ → ηγ . We observed (27 ± 6) events, yielding a branching ratio Γ(φ → ηγ) Γ(φ → total ) = (7.3 ± 1.9)% . The theoretical implications of this result are discussed.

1 data table

ASSUMING THE TOTAL PHI CROSS SECTION IS 35 +- 5 MUB, THIS YIELDS THE BRANCHING RATIO OF (7.3 +- 1.9) PCT FOR PHI --> ETA GAMMA.


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.



The Threshold Photoproduction of pi0 on Nucleons and on Few Nucleon Systems

Argan, P. ; Audit, G. ; Bloch, A. ; et al.
Phys.Lett.B 206 (1988) 4, 1988.
Inspire Record 251858 DOI 10.17182/hepdata.29971

The absolute value of the π 0 photoproduction cross section on the proton recently measured near threshold enables to reanalyze previous data collected on 2 H, 3 He, and 4 He relatively to the proton. Absolute cross sections are presented for these nuclei in the energy region extending up to 10 MeV above threshold. The threshold s-wave amplitudes for 2 H and 3 He thus obtained are discussed in relation with the neutron threshold amplitude E ( nπ 0 ) 0+ value.

4 data tables

No description provided.

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A Large Solid Angle Study of Pion Absorption on He3

The LADS collaboration Alteholz, T. ; Androic, D. ; Backenstoss, G. ; et al.
Phys.Rev.Lett. 73 (1994) 1336-1339, 1994.
Inspire Record 372679 DOI 10.17182/hepdata.19679

Measurements have been made of pi+ absorption on He3 at T_pi+ = 118, 162, and 239 MeV using the Large Acceptance Detector System (LADS). The nearly 4pi solid angle coverage of this detector minimizes uncertainties associated with extrapolations over unmeasured regions of phase space. The total absorption cross section is reported. In addition, the total cross section is divided into components in which only two or all three nucleons play a significant role in the process. These are the first direct measurements of the total and three nucleon absorption cross sections.

2 data tables

ABSORPTION CROSS SECTION.

ABSORPTION CROSS SECTION.


Observation of enhanced subthreshold K+ production in central collisions between heavy nuclei

Miskowiec, D. ; Ahner, W. ; Barth, R. ; et al.
Phys.Rev.Lett. 72 (1994) 3650-3653, 1994.
Inspire Record 373335 DOI 10.17182/hepdata.19695

In the very heavy collision system Au197+197Au the K+ production process was studied as a function of impact parameter at 1 GeV/nucleon, a beam energy well below the free N-N threshold. The K+ multiplicity increases more than linearly with the number of participant nucleons and the K+/π+ ratio rises significantly when going from peripheral to central collisions. The measured K+ double differential cross section is enhanced by a factor of 6 compared to microscopic transport calculations if secondary processes (ΔN→KΛN and ΔΔ→KΛN) are ignored.

2 data tables

No description provided.

The total K+ cross section is determined by extrapolating and integrating the double differential cross section d2(sig)/d(p)/d(omega) over momentum and solid angle.


Measurement of the reaction C-12 (muon-neutrino, mu-) X near threshold

The LSND collaboration Albert, M. ; Athanassopoulos, C. ; Auerbach, L.B. ; et al.
Phys.Rev.C 51 (1995) 1065-1069, 1995.
Inspire Record 378770 DOI 10.17182/hepdata.25973

The reaction $~{12}{\rm C}(\nu_\mu,\mu~-) {\rm X}$ has been measured near threshold using a $\pi ~+$ decay-in-flight $\nu_\mu$ beam from the Los Alamos Meson Physics Facility and a massive liquid scintillator neutrino detector (LSND). In the energy region $123.7 < {\rm E}_\nu < 280$ MeV, the measured spectral shape is consistent with that expected from the Fermi Gas Model. However, the measured flux--averaged inclusive cross section ($(8.3 \pm 0.7 {\rm stat.} \pm 1.6 {\rm syst.}) \times 10~{-40} {\rm cm}~2$) is more than a factor of 2 lower than that predicted by the Fermi Gas Model and by a recent random phase approximation calculation.

1 data table

No description provided.


Jets of nuclear matter in He-A(T) inelastic collisions at 4.5-A-GeV/c.

Besliu, C. ; Jipa, A. ; Zaharia, R. ; et al.
Eur.Phys.J.A 1 (1998) 65-75, 1998.
Inspire Record 467239 DOI 10.17182/hepdata.43769

The problem of the nuclear matter jets in nucleus-nucleus collisions at 4.5 A GeV/c is discussed. The global analysis of experimental data, namely the sphericity tensor, is used to evidence such jets.

3 data tables

No description provided.

No description provided.

No description provided.


Cross section of the $pp\to K^+\Sigma^+n$ reaction close to threshold

The COSY-HIRES collaboration Budzanowski, A. ; Chatterjee, A. ; Clement, H. ; et al.
Phys.Lett.B 692 (2010) 10-14, 2010.
Inspire Record 861052 DOI 10.17182/hepdata.55371

We have measured inclusive data on $K^+$-meson production in $pp$ collisions at COSY J\"ulich close to the hyperon production threshold and determined the hyperon-nucleon invariant mass spectra. The spectra were decomposed into three parts: $\Lambda p$, $\Sigma^0p$ and $\Sigma^+n$. The cross section for the $\Sigma^+n$ channel was found to be much smaller than a previous measurement in that excess energy region. The data together with previous results at higher energies are compatible with a phase space dependence.

3 data tables

Total cross section for P P --> K+ SIGMA+ N. Errors are combined statistics and systematics.

Deduced total cross section for P P --> K+ P LAMBDA.

Deduced total cross section for P P --> K+ SIGMA0 P.


Study of the gp-->etap reaction with the Crystal Ball detector at the Mainz Microtron(MAMI-C)

The Crystal Ball at MAMI collaboration McNicoll, E.F. ; Prakhov, S. ; Strakovsky, I.I. ; et al.
Phys.Rev.C 82 (2010) 035208, 2010.
Inspire Record 860725 DOI 10.17182/hepdata.56733

The gp-->etap reaction has been measured with the Crystal Ball and TAPS multiphoton spectrometers in the energy range from the production threshold of 707 MeV to 1.4 GeV (1.49 =< W >= 1.87 GeV). Bremsstrahlung photons produced by the 1.5-GeV electron beam of the Mainz Microtron MAMI-C and momentum analyzed by the Glasgow Tagging Spectrometer were used for the eta-meson production. Our accumulation of 3.8 x 10^6 gp-->etap-->3pi0p-->6gp events allows a detailed study of the reaction dynamics. The gp-->etap differential cross sections were determined for 120 energy bins and the full range of the production angles. Our data show a dip near W = 1680 MeV in the total cross section caused by a substantial dip in eta production at forward angles. The data are compared to predictions of previous SAID and MAID partial-wave analyses and to thelatest SAID and MAID fits that have included our data.

121 data tables

Total cross section for the reaction GAMMA P --> ETA P.

Differential cross section for the reaction GAMMA P --> ETA P at a photon energy of 710.4 MeV. The errors in the table are statistical only and there is an overall systematic uncertainty of 4.3 PCT.

Differential cross section for the reaction GAMMA P --> ETA P at a photon energy of 714.5 MeV. The errors in the table are statistical only and there is an overall systematic uncertainty of 4.3 PCT.

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