MEASUREMENT OF PION CHARGE EXCHANGE IN THE REGION OF THE S11(1535) RESONANCE

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1822-1825
Author(s):  
◽  
S. PRAKHOV ◽  
A. STAROSTIN
Keyword(s):  
Charge Exchange ◽  
Cross Sections ◽  
Differential Cross ◽  
Partial Wave Analysis ◽  
Sources Of Information ◽  
Momentum Range ◽  
Total Uncertainty ◽  
Section Data ◽  
Data Points ◽  
Pion Nucleon

Pion charge-exchange (π-p→π0n) differential cross sections are one of the basic sources of information on neutral pion-nucleon resonances. We present new, high statistics, high quality charge-exchange differential cross-section data obtained in the incident π- momentum range 650–750 MeV/c. The total uncertainty of the measurements is 6% or less. 648 new data points were obtained using the Crystal Ball multiphoton spectrometer covering 94% of the full solid angle. Our data show deviations from the results of the partial–wave analysis for some momenta, in particular at very backward angles. We also report on a search for the cusp effect in π-p→π0n at the opening of the π-p→ηn channel.

New analysis of the low-energy π±p differential cross-sections of the CHAOS Collaboration

2015 ◽  
Vol 24 (07) ◽  
pp. 1550050 ◽  
Author(s):  
E. Matsinos ◽  
G. Rasche
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Differential Cross ◽  
Form Factors ◽  
Partial Wave Analysis ◽  
Meson Mass ◽  
Data Sets ◽  
Differential Cross Sections ◽  
Pion Nucleon ◽  
Meson Factory

In a previous paper, we reported the results of a partial-wave analysis (PWA) of the pion–nucleon (πN) differential cross-sections (DCSs) of the CHAOS Collaboration and came to the conclusion that the angular distribution of their π+p data sets is incompatible with the rest of the modern (meson factory) database. The present work, re-addressing this issue, has been instigated by a number of recent improvements in our analysis, namely regarding the inclusion of the theoretical uncertainties when investigating the reproduction of experimental data sets on the basis of a given "theoretical" solution, modifications in the parametrization of the form factors of the proton and of the pion entering the electromagnetic part of the πN amplitude, and the inclusion of the effects of the variation of the σ-meson mass when fitting the ETH model of the πN interaction to the experimental data. The new analysis of the CHAOS DCSs confirms our earlier conclusions and casts doubt on the value for the πN Σ term, which Stahov, Clement and Wagner have extracted from these data.

scholarly journals MEASUREMENT OF DIFFERENTIAL CROSS SECTIONS OF p(e, e′π+)n FOR HIGH-LYING RESONANCES AT Q2 < 5 GeV2

2014 ◽  
Vol 26 ◽  
pp. 1460102
Author(s):  
◽  
KIJUN PARK
Keyword(s):  
Cross Sections ◽  
Differential Cross ◽  
Center Of Mass ◽  
Differential Cross Sections ◽  
Cross Section Data ◽  
Photon Virtuality ◽  
Mass System ◽  
Section Data ◽  
Data Points ◽  
First Time

The exclusive electroproduction process ep → e′nπ+ was measured in the range of the invariant mass for nπ+ system 1.6 GeV ≤ W ≤ 2.0 GeV, and the photon virtuality 1.8 GeV2 ≤ Q2 ≤ 4.0 GeV2 using CLAS. For the first time, these kinematics are probed in exclusive π+ production from the protons with nearly full coverage in the azimuthal and polar angles of the nπ+ center-of-mass system. In this experiment, approximately 39,000 differential cross-section data points were measured. In this conference proceeding, preliminary results of our latest analysis work are presented on differential cross sections and structure functions as well as Legendre Moments.

scholarly journals Differential cross sections of the charge-exchange reactionπ−p→π0nin the momentum range from103to178MeV/c

2009 ◽  
Vol 80 (5) ◽  
Author(s):  
D. Mekterović ◽  
I. Supek ◽  
V. Abaev ◽  
V. Bekrenev ◽  
C. Bircher ◽  
...  
Keyword(s):  
Charge Exchange ◽  
Cross Sections ◽  
Differential Cross ◽  
Differential Cross Sections ◽  
Momentum Range

Measurements of differential cross sections and polarization effects in pion-proton elastic scattering in the momentum range 875 to 1579 MeV/ c

1966 ◽  
Vol 289 (1419) ◽  
pp. 449-462 ◽  
Keyword(s):  
Elastic Scattering ◽  
Cross Sections ◽  
Differential Cross ◽  
Pulse Height ◽  
Magnetic Core ◽  
Differential Cross Sections ◽  
Liquid Hydrogen Target ◽  
Hydrogen Target ◽  
Momentum Range ◽  
Polarization Effects

In this paper we discuss some measurements that have been made at Nimrod of differential cross sections and polarization effects in πp elastic scattering. The principal aims of this work were to determine the spins and parities of the N * 1/2 (1688) and the N* 3/2 (1920) isobars and to examine the behaviour of the π+p elastic scattering cross section at momenta around 950MeV/ c where a shoulder exists in the total cross sections. Table 1 gives the values of the momenta at which the measurements were made and figure 1 illustrates their relation to other work that has been done in or near this region. A schematic diagram of the experimental arrangement for measuring the differential cross sections is shown in figure 2. An array of scintillation counters, used in conjunction with a coincidence matrix detected particles scattered from a 4 in. long liquid hydrogen target. All events were accepted in which two and only two outgoing particles were detected in coincidence by any combination of two counters on opposite sides of the beam. The number of counts for each combination was stored in the magnetic core store of a 512 channel pulse height analyser

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