$\pi^+$ production with linearly polarized photons

Geweniger, C. ; Heide, P. ; Kötz, U. ; et al.
Phys.Lett.B 29 (1969) 41-44, 1969.
Inspire Record 56795 DOI 10.17182/hepdata.29060

Single π + production on protons by linearly polarized photons of 2.5 to 5 GeV was measured at squared four momentum transfers t between −0.01 and −0.6 (GeV/ c ) 2 . The results show that the differential cross section d σ ⊥ d t with the electric vector of the photon perpendicular to the reaction plane is much larger than d σ ‖ d t with the electric vector parallel to the reaction plane. The predictions of Regge models and of the vector meson dominance model are briefly discussed.

3 data tables

Axis error includes +- 0.0/0.0 contribution (?////).

Axis error includes +- 0.0/0.0 contribution (?////).

Axis error includes +- 0.0/0.0 contribution (?////).


The annihilation process p anti-p ---> 2pi+ 2pi- pi0 at 2.5 gev/c

Clayton, J. ; Mason, P. ; Muirhead, H. ; et al.
Nucl.Phys.B 30 (1971) 605-616, 1971.
Inspire Record 68592 DOI 10.17182/hepdata.33476

Substantial production of the resonances ϱ, f and ω has been observed in this reaction. In contrast with the channel p p → 2π + 2π − , associated production of resonances was found to occur. The behaviour of the associated production of ω-mesons with other resonances is shown to be consistent with some very simple assumptions. Alternative methods of displaying data for p p → ππω are discussed; it is shown that the longitudinal phase plot for this reaction is unlike that obtained for any previously reported reaction. Reasonable agreement for the behaviour of this channel is found with the multiperipheral model of Chan, Łoskiewicz and Allison.

2 data tables

STATISTICAL ERRORS ONLY. FOR MULTIPLE PI0 PRODUCTION, RESULTS ARE MODEL DEPENDENT.

ANALYSIS OF 5PION FINAL STATE. DISTRIBUTION FITTED WITH FIXED MASS AND WIDTH RESONANCES, THEN ONLY EVENTS ABOVE (FITTED) BACKGROUND TAKEN. CROSS SECTIONS CALCULATED BY PDG (COMPILATION PDG3).


Backward photoproduction of neutral pions off hydrogen at photon energies between 0.4 and 2.2 gev

Becks, H. ; Feller, P. ; Menze, D. ; et al.
Nucl.Phys.B 60 (1973) 267-276, 1973.
Inspire Record 83927 DOI 10.17182/hepdata.6749

The differential cross section has been measured for the reaction γ +p→p+ π o at the Bonn 2.5 GeV electron synchrotron in the energy range from 0.4 to 2.2 GeV for a c.m. angle of 150 degrees. The protons were detected in a magnetic spectrometer system. The excitation curve shows a distinct resonance structure. The total corrections to the counting rate are about 3%. The contribution of the process γ +p→p+2 π was separated. The uncertainty of this separation leads to an error of about 4% in the cross section.

2 data tables

No description provided.

No description provided.


Photoproduction of pi+ mesons on polarized protons at photon energies between 0.5 and 2.2 gev

Althoff, K.H. ; Feller, P. ; Herr, H. ; et al.
Nucl.Phys.B 53 (1973) 9-18, 1973.
Inspire Record 84220 DOI 10.17182/hepdata.32593

The target asymmetry T = ( σ ↑ − σ ↓)/( σ ↑ + σ ↓) for the reaction γ p → π + n has been measured at the Bonn 2.5 GeV electron synchrotron for a pion c.m. angle of 40° and γ energies between 0.5 and 2.2 GeV. Butanol was used as the target material. About 35% of the protons could be polarized using the dynamic-polarization method in a continuous-flow cryostat operating at 1°K and 25 kG. The π + mesons were detected in a magnetic-spectrometer system. Considerable structure in the asymmetry was observed.

1 data table

Axis error includes +- 11/11 contribution.


K+ p Interactions Near 3-GeV/c. 2. Baryon Resonance Production

Musgrave, B. ; Peeters, P. ; Schreiner, P. ; et al.
Nucl.Phys.B 87 (1975) 365-398, 1975.
Inspire Record 1720 DOI 10.17182/hepdata.1112

Baryon resonance production in quasi-two-body reactions has been studied for the channels K + p→K°p π + , K + n π + and K + p π ° at beam momenta of 2.53, 2.76 and 3.20 GeV/ c . The production cross sections, four-momentum transfer distributions and density matrix elements are given for the Δ(1236), N ∗ (1400), N ∗ (1500) and N ∗ (1680) states. The reaction K + p→K° Δ ++ (1236) is compared to the line reversed reaction K − n → K °Δ − and the charge-exchange SU(3) sum rule for pseudo-scalar meson plus Δ(1236) is tested.

7 data tables

No description provided.

No description provided.

No description provided.

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Measurement of the Real Part of the Forward Amplitude in anti-p p Elastic Scattering

Jenni, P. ; Baillon, P. ; Bricman, C. ; et al.
Nucl.Phys.B 94 (1975) 1-20, 1975.
Inspire Record 99005 DOI 10.17182/hepdata.31973

The differential cross sections of the elastic p p reaction have been measured at 1.2, 1.4, 1.8 and 2.6 GeV/ c incident p momentum. The measurements have been performed at the CERN PS using a system of multiwire proportional chambers. The angular region covers scattering angles from 0 to ∼200 mrad. Interference effects between the Coulomb and the nuclear amplitudes are used to derive the ratio of the real to imaginary part of the forward nuclear amplitude. These ratios are compared with theoretical predictions.

6 data tables

'MS'. 'TBIN'.

'MS'. 'TBIN'.

'MS'. 'TBIN'.

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Partial-wave analyses of the (3π)-system in the reaction π − p → π − π − π + p at 11.2 GeV/ c

The Bologna-Florence-Genoa-Milan-Oxford-Pavia collaboration Thompson, G. ; Antich, P. ; Boldetti, A. ; et al.
Nucl.Phys.B 101 (1975) 285-303, 1975.
Inspire Record 2860 DOI 10.17182/hepdata.36138

The results are presented of two partial-wave analyses of the (3π) − system in 30 000 events of the reaction π − p → π − π − π + p at 11.2 GeV/ c . Both techniques incorporate the assumptions of the isobar model and are (a) the University of Illinois program which fits in terms of the (3π) density matrix elements and (b) an amplitude parametrisaton including possible effects of both spin non-flip and spin flip at the baryon vertex. The results obtained with these independent programs are found to be very close.

2 data tables

NORMALIZED TO A TOTAL REACTION CROSS SECTION OF 1.17 +- 0.24 MB. ALL QUOTED CROSS SECTIONS ARE FOR INTEGRATED BREIT-WIGNERS.

A2 2+D-WAVE FOR 1.2 < M(3PI) < 1.4 GEV. THE FIRST THREE COMBINATIONS OF DENSITY MATRIX ELEMENTS ARE FOR NATURAL PARITY EXCHANGE, AND THE REMAINDER UNNATURAL.


Measurement of the Real Part of the K- n Forward Scattering Amplitude Between 1.2-GeV/c and 2.6-GeV/c

Jenni, P. ; Baillon, P. ; Bricman, C. ; et al.
Nucl.Phys.B 105 (1976) 1-22, 1976.
Inspire Record 100905 DOI 10.17182/hepdata.35921

The differential cross sections of the combined elastic and break-up K − d reaction have been measured at 1.21, 1.42 and 2.61 GeV/ c incident K − momentum. The measurements have been performed at the CERN PS using multiwire proportional chambers. The values of the invariant momentum transfer t explored (0.0005<| t |<0.1 GeV 2 ) include the Coulomb-nuclear interference region. The differential cross sections have been analysed in the framework of the Glauber impact-parameter formalism. The observed interference effects have been used to derive the ratio of the real to imaginary part of the forward K − n nuclear amplitude.

4 data tables

SUM OF COHERENT AND BREAK-UP SCATTERING.

SUM OF COHERENT AND BREAK-UP SCATTERING.

SUM OF COHERENT AND BREAK-UP SCATTERING.

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Polarization Measurements around the Secondary Dip in pip Elastic Scattering

Auer, P. ; Giese, R. ; Hill, D. ; et al.
Phys.Rev.Lett. 37 (1976) 83-84, 1976.
Inspire Record 945158 DOI 10.17182/hepdata.21039

Polarization in π−p elastic scattering, with emphasis in the region around the secondary dip and also θc.m.=90°, has been measured at 2.93 and 3.25 GeV/c. We observe an interesting sign change in this angular region.

2 data tables

No description provided.

No description provided.


A Study of the Reactions K- d --> K- d and K- d --> K- n p(s) at 4.5-GeV/c

De Clercq, C. ; Johnson, D. ; Lemonne, J. ; et al.
Nucl.Phys.B 126 (1977) 397-416, 1977.
Inspire Record 120578 DOI 10.17182/hepdata.35285

Results are presented concerning K − d and K − n elastic scattering at an incident momentum of 4.5 GeV/ c . The high-energy Glauber formalism has been used in analyzing the data in which the nucleon scattering amplitudes are parameterized and employing the spherical and quadrupole deuteron form factors. An impulse approximation analysis of the K − n differential scattering cross section fitted to a single exponential of the form d σ /d t ) 0 e Bt , leads to the result (d σ /d t ) 0 = 21.3 + mn ; 5.5 mb/(GeV/ c ) 2 and B = 6.9 + mn ; 0.5 (GeV/ c ) −2 . A global fit has been made to existing K + mn; N two-body scattering data at this energy in order to determine the scattering amplitudes. It was found that the K − n and K − p elastic amplitudes are dominantly imaginary with a relatively small contribution from spin-flip amplitudes. The slopes of the differential elastic cross sections for K − n and K − p are nearly equal, as are those for K + n and K + p. However, the value of the slope for K + is smaller than that for K − at this energy.

3 data tables

No description provided.

No description provided.

No description provided.