A Measurement of the Cross-Section for Four Pion Production in gamma gamma Collisions at SPEAR

Burke, D.L. ; Abrams, G.S. ; Alam, M.S. ; et al.
Phys.Lett.B 103 (1981) 153-156, 1981.
Inspire Record 165016 DOI 10.17182/hepdata.31168

We present a measurement of the cross section for the reaction e + e − → e + e − π + π − π + π − at SPEAR. This channel is found to be large and dominated by the process γγ → ϱ 0 ϱ 0 → π + π − π + π − . The cross section, which is small just above the four-pion threshold, exhibits a large enhancement near the ϱ 0 ϱ 0 threshold.

1 data table match query

Axis error includes +- 0.0/0.0 contribution (THE QUOTED ERRORS INCLUDE VARIOUS SYSTEMATIC ERRORS ADDED QUADRATICALLY).


A STUDY OF DOUBLE TAGGED TWO PHOTON REACTIONS AT SPEAR

Biddick, C.J. ; Burnett, T.H. ; Lyon, D.E. ; et al.
Phys.Lett.B 97 (1980) 320, 1980.
Inspire Record 159793 DOI 10.17182/hepdata.27144

We have identified 262 doubly tagged two-photon events. A subset of the data shows an enhancement of 21 events in the inclusive two-photon mass squared distribution between 0.8 and 2.2 GeV 2 . If these events result from spin 2 resonance production then Γ γγ = 9.5 ± 3.9 ± 2.4 keV (statistical and systematic). From another subset of 58 events in which the final state could be classified we determine the two-photon hadron to muon cross section ratio R γγ = 1.1 ± 0.3 ± 0.3.

1 data table match query

ELECTRON BEAM ENERGIES OF 3.0 AND 3.6 GEV.


A measurement of the electric form-factor of the neutron through d(pol.)(e(pol.),e' n)p at Q**2 = 0.5-(GeV/c)**2.

The E93026 collaboration Zhu, H. ; Ahmidouch, A. ; Anklin, H. ; et al.
Phys.Rev.Lett. 87 (2001) 081801, 2001.
Inspire Record 556212 DOI 10.17182/hepdata.31418

We report the first measurement of the neutron electric form factor $G_E^n$ via $\vec{d}(\vec{e},e'n)p$ using a solid polarized target. $G_E^n$ was determined from the beam-target asymmetry in the scattering of longitudinally polarized electrons from polarized deuterated ammonia, $^{15}$ND$_3$. The measurement was performed in Hall C at Thomas Jefferson National Accelerator Facility (TJNAF) in quasi free kinematics with the target polarization perpendicular to the momentum transfer. The electrons were detected in a magnetic spectrometer in coincidence with neutrons in a large solid angle segmented detector. We find $G_E^n = 0.04632\pm0.00616 (stat.) \pm0.00341 (syst.)$ at $Q^2 = 0.495$ (GeV/c)$^2$.

1 data table match query

No description provided.


ASYMMETRY IN SINGLE pi0 PHOTOPRODUCTION BY POLARIZED gamma RAYS ON PROTONS

Bologna, G. ; Fabbri, F.L. ; Spillantina, P. ; et al.
LNF-70-39, 1970.
Inspire Record 1105046 DOI 10.17182/hepdata.37903

None

1 data table match query

No description provided.


ASYMMETRY MEASUREMENTS IN PION PHOTOPRODUCTION BY POLARIZED PHOTONS IN THE ENERGY RANGE FROM 250-MeV TO 600-MeV

Antufev, Yu.P. ; Agranovich, V.L. ; Ganenko, V.B. ; et al.
PRINT-70-2307, 1970.
Inspire Record 1105361 DOI 10.17182/hepdata.75432

None

1 data table match query

No description provided.


Analysis of the pi+ pi- pi+ pi- and pi+ pi0 pi- pi0 final states in quasi-real two-photon collisions at LEP.

The L3 collaboration Achard, P. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 638 (2006) 128-139, 2006.
Inspire Record 705125 DOI 10.17182/hepdata.48674

The reactions gamma gamma -> pi^+pi^-pi^+pi^- and gamma gamma -> pi^+pi^0pi^-pi^0 are studied with the L3 detector at LEP in a data sample collected at centre-of-mass energies from 161GeV to 209GeV with a total integrated luminosity of 698/pb. A spin-parity-helicity analysis of the rho^0 rho^0 and rho^+ rho^- systems for two-photon centre-of-mass energies between 1GeV and 3GeV shows the dominance of the spin-parity state 2+ with helicity 2. The contribution of 0+ and 0- spin-parity states is also observed, whereas contributions of 2- states and of a state with spin-parity 2+ and zero helicity are found to be negligible.

4 data tables match query

Cross section for 4PI and (RHO0 RHO0) production.

Cross section for 4PI and (RHO+ RHO-) production.

Spin parity analysis fits for RHO0 RHO0.

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Analysis of the reaction gamma n ---> p pi- in the first and second resonance regions

Rossi, V. ; Piazza, A. ; Susinno, G. ; et al.
Nuovo Cim.A 13 (1973) 59-89, 1973.
Inspire Record 87242 DOI 10.17182/hepdata.37785

The final results of an experimental investigation of the reaction γ+n→p+π− performed with a deuterium bubble chamber at the 1 GeV Frascati electrosynchrotron are presented. Total and differential cross-sections on neutrons are extracted by means of the spectator model, the reliability of which has been checked by numerous tests and is extensively discussed. The problems of a possible isotensor component in the electromagnetic current, the time-reversal invariance of the electromagnetic interactions and the photoproduction of the Roper resonance are considered in detail.

6 data tables match query

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Angular dependence of the recoil proton polarization from the reaction $\gamma p \to \pi^0 p$ for photon energies between 360-MeV and 1200-MeV

Blum, P. ; Brinckmann, P. ; Brockmann, R. ; et al.
BONN-PI-1-105, 1970.
Inspire Record 1085812 DOI 10.17182/hepdata.70500

None

1 data table match query

No description provided.


Angular distributions for single neutral pion photoproduction from neutrons at 450-800 mev

Bacci, C. ; Baldini-Celio, R. ; Esposito, B. ; et al.
Phys.Lett.B 39 (1972) 559-562, 1972.
Inspire Record 75766 DOI 10.17182/hepdata.28319

Differential cross sections for single photoproduction of neutral pion on neutron have been measured at different c.m. angles for photon energies, between 450–800 MeV.

1 data table match query

No description provided.


Angular distributions of the asymmetry of the gamma p ---> p pi0 reaction with the gamma-quanta energies of 400, 450, 500, 550, 650 mev

Ganenko, V.B. ; Gorbenko, V.G. ; Zhebrovskii, Yu.V. ; et al.
Yad.Fiz. 20 (1974) 356-358, 1974.
Inspire Record 95035 DOI 10.17182/hepdata.19140

None

3 data tables match query

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