Polarization of the Recoil Proton from the Neutral Photoproduction at 800 and 910 Mev

Mencuccini, C. ; Querzoli, R. ; Salvini, G. ;
Phys.Rev. 126 (1962) 1181-1182, 1962.
Inspire Record 944983 DOI 10.17182/hepdata.26790

The measurements on the polarization of the recoil protons from the process γ+p→π0+p have been extended to higher γ-ray energies, at 90° in the center-of-mass system. We have found at 910 Mev a polarization, P=−0.45±0.07; at 800 Mev, P=−0.42±0.10. The rather high values of P agree with the hypothesis that the neutral photoproduction in the 500-1000 Mev range can be described by the well-known three resonant states, and strongly indicate that the second and third resonance have opposite parity. The probable quantum numbers are: T=12, J=32, D pion wave for the second resonance; T=12, J=52, F wave for the third resonance.

1 data table

No description provided.


The polarization of the proton from the process γ+p→p+$\pi^{0}$ in the region of the higher resonances

Querzoli, R. ; Salvini, G. ; Silverman, A. ;
Nuovo Cim. 19 (1961) 53-76, 1961.
Inspire Record 1185001 DOI 10.17182/hepdata.37767

The polarization of the recoil proton in the photoproduction process γ+p→p+π0 has been measured with the beam of the Frascati electrosynchrotron at an angle of 90° in the c.m. system, in the energy interval (500÷900) MeV. A counter technique has been used, and the polarization of the proton was revealed by the left to right asymmetry in the elastic scattering of the protons in a carbon target. The experimental results are given in Table III and in Fig. 10. A definite polarization is found, always of the same sign and equal to −0.4±.14, −0.63±.23, −0.6±.25, −0.57±.12, −0.38±.09, −0.5±.17, −0.5±.22 at the γ-ray energies of 560, 610, 650, 700, 750, 800, 850 MeV respectively. The discussion of these experimental results, together with the data of angular dstributions, allows to conclude that they are in agreement with the hypothesis that the second resonance is a transition (E 1,d 3/2) and the third one is a transition (E 2,f 3/2).

1 data table

No description provided.


Photoproduction of the Eta Particle at 800-1000 MeV. A Comparison Between the piN and the etaN Systems

Bacci, C. ; Penso, G. ; Salvini, G. ; et al.
Phys.Rev.Lett. 16 (1966) 157-161, 1966.
Inspire Record 944921 DOI 10.17182/hepdata.21793

None

1 data table

No description provided.


Photoproduction and Neutral Decay Models of the eta Particle

Bacci, C. ; Penso, G. ; Salvini, G. ;
Phys.Rev.Lett. 11 (1963) 37, 1963.
Inspire Record 48435 DOI 10.17182/hepdata.21858

None

1 data table

Axis error includes +- 0.0/0.0 contribution (?////The errors include an uncertainties in solid angle, efficiency, and background).


Photoproduction of Neutral Pions for Incident Photon Energies 400-800 MeV. Search for a Resonant P-11 State and Remarks on the eta Cusp Effect

Bacci, C. ; Penso, G. ; Salvini, G. ; et al.
Phys.Rev. 159 (1967) 1124-1137, 1967.
Inspire Record 944952 DOI 10.17182/hepdata.37216

Cross sections for the photoproduction of neutral pions have been measured at the 1.1-GeV Frascati electron synchrotron for bombarding photon energies k between 400 and 800 MeV and for π0 c.m. angles of θπ*=90∘, 120∘, and 135∘. The main feature of the experiment is good resolution in incident photon energy. The results are in good agreement with the existing theories in the energy range of 450 to 550 MeV. The cross sections exhibit a smooth behavior as a function of energy for k=400−600 MeV. No immediate evidence is found of a contribution of the P11 resonance. An anomaly at the limit of statistical significance appears for k≃700−740 MeV, indicating a possible structure of the so-called second resonance. We attempt to interpret the observed anomaly as a reflection of the sharp opening of the η production channel (η cusp effect).

1 data table

No description provided.


η photoproduction cross-section for incident photon energies from 800 to 1000 MeV

Bacci, C. ; Penso, G. ; Salvini, G. ; et al.
Nuovo Cim.A 45 (1966) 983-1009, 1966.
Inspire Record 1185323 DOI 10.17182/hepdata.37560

Photoproduction cross-section of the η-particle for incident photon energiesK from ∼800 to ∼1000 MeV has been measured at the 1.1 GeV Frascati electronsynchrotron. The differential cross-section for this process, at a c.m. angle of the η of ∼110°, turns out to be fairly constant for 830 MeV≤K≤900 MeV, and drops down by a factor 5 to 10 atK=950 MeV. These results are discussed in terms of a comparison with the data on the production of η's by pions, and with the data on pion-nucleon scattering and pion photoproduction. The conclusions are in agreement with the hypothesis that the η-N system is dominated at low energies by a resonance with orbital angular momentuml=0 (S 1/2,1/2 resonance).

1 data table

No description provided.


Multihadronic cross-sections from e+ e- annihilation at c.m. energies between 1.4 and 2.4 gev

Bacci, C. ; Penso, G. ; Salvini, G. ; et al.
Phys.Lett.B 38 (1972) 551-554, 1972.
Inspire Record 75822 DOI 10.17182/hepdata.28322

Multihadronic production has been observed at the Adone e + e − storage ring, in the c.m. energy range 1.4 - 2.4 GeV. The cross sections for the reactions e + + e − → 2 π ± + nπ o (1 ⩽ n ⩽ 4) and e + + e − → (4 π ± + nπ ± ) (0 ⩽ n ⩽ 2) have been measured, assuming that the produced particles are only pions with a pure phase space momentum distribution.

1 data table

No description provided.


Multihadronic cross-sections from e+ e- annihilation up to 3 gev center-of-mass energy

Bacci, C. ; Penson, G. ; Salvini, G. ; et al.
Phys.Lett.B 44 (1973) 533-536, 1973.
Inspire Record 84794 DOI 10.17182/hepdata.6496

With an apparatus slightly improved with respect to a previous one we have studied multihadronic production at the Adone e + e − storage ring up to a maximum center of mass energy of 3 GeV.

4 data tables

No description provided.

No description provided.

No description provided.

More…

Transverse Momentum Spectra for Charged Particles at the CERN Proton anti-Proton Collider

The UA1 collaboration Arnison, G. ; Astbury, A. ; Aubert, Bernard ; et al.
Phys.Lett.B 118 (1982) 167-172, 1982.
Inspire Record 179520 DOI 10.17182/hepdata.30855

We have measured transverse momentum spectra up to 10 GeV/ c for charged particles produced centrally in proton-antiproton collisions at 540 GeV in the centre of mass at the CERN collider. Our results are compared with data at ISR energies and with the predictions of a QCD model. The charged particle spectrum shows a clear dependence on charged track multiplicity.

2 data tables

No description provided.

No description provided.


Charged Particle Multiplicity Distributions in Proton Anti-proton Collisions at 540-{GeV} Center-of-mass Energy

The UA1 collaboration Arnison, G. ; Astbury, A. ; Aubert, Bernard ; et al.
Phys.Lett.B 123 (1983) 108-114, 1983.
Inspire Record 182553 DOI 10.17182/hepdata.30779

Results on charged particle production in pp̄ collision at s 1 2 = 540 GeV are presented. The data were obtained at the CERN pp̄ collider using the UA1 detector, operated without magnetic field. The central particle density is 3.3 + - 0.2 per unit o pseudo-rapidity for non-diffractive events. KNO scaling of the multiplicity distributions withresults from ISR energies is observed.

6 data tables

Pseudorapidity density distribution for all charged multiplicities corrected for acceptance and backgrounds by excluding NSD events. Data have been read from the plot.

More…