STUDY OF EXCITED NUCLEONS AND THEIR STRUCTURE

Pion beams are perfect tools to probe resonance excitations at a fixed energy, thus properties of baryonic resonances and their coupling channels can be studied. The HADES Collaboration performed a systematic scan around the second resonance region at four different pion beam momenta 0.656, 0.69, 0.748 and 0.8 GeV/c in π− p reaction. The role of the N(1520) resonance in conjunction with the intermediate ρ-meson production has been studied in the framework of a partial wave analysis. Preliminary results on exclusive channels with one pion (π− p) and two pions (nπ+π− and pπ−π0) in the final state are presented.

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MESON PRODUCTION FROM DIFFRACTIVE PION DISSOCIATION AT COMPASS

International Journal of Modern Physics A ◽

10.1142/s0217751x09043900 ◽

2009 ◽

Vol 24 (02n03) ◽

pp. 484-487

Author(s):

◽

QUIRIN WEITZEL

Keyword(s):

Momentum Transfer ◽

Partial Wave ◽

Meson Production ◽

Beam Momentum ◽

Partial Wave Analysis ◽

Wave Analysis ◽

High Quality ◽

Diffractive Dissociation ◽

Mass Dependent

Diffractive dissociation reactions at COMPASS provide clean access to mesons with masses below ≈ 2.5 GeV /c2. This paper presents a partial wave analysis of about 420 000 π- Pb → π-π-π+ Pb events at 190 GeV/c beam momentum and with four-momentum transfer t' ∈ [0.1,1] GeV 2/c2. The well-known a1(1260), a2(1320) and π2(1670) mesons are resolved with high quality. Also the less established states π(1800) and a4(2040) are seen. In addition, a resonance in the spin-exotic JPC = 1-+ wave is observed. A mass-dependent fit results in a mass and width of [Formula: see text] and [Formula: see text], respectively, which is consistent with the disputed hybrid candidate π1(1600).

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Partial Wave Analysis of HADES Data for Two-Pion Production in Pion-Nucleon Reactions

EPJ Web of Conferences ◽

10.1051/epjconf/202024103001 ◽

2020 ◽

Vol 241 ◽

pp. 03001

Author(s):

I. Ciepał

Keyword(s):

Partial Wave ◽

Meson Production ◽

Resonance Region ◽

Partial Wave Analysis ◽

Wave Analysis ◽

Final State ◽

Decay Channels ◽

Hades Collaboration ◽

Pion Nucleon

Pion beams are important tools to study features of baryonic resonances and their decay channels because resonances are produced in s-channel at fixed mass equal to √s. In 2014 the HADES collaboration has performed systematic measurements in the second resonance region scanning around the mass of the N*(1520). Pion beams at four momenta (0.654, 0.686, 0.738 and 0.787 GeV/c) impinging on polyethylene and carbon targets have been used. With the use of the multichannel Partial Wave Analysis (PWA) the role of the N*(1520) resonance in conjunction with the intermediate ρ-meson production has been studied. Preliminary results at 0.654 GeV/c on exclusive production of two pions (ηπ+π- and pπ-π0) in the final state are presented.

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Partial wave analysis of HADES data for two-pion production in pion-nucleon reactions

EPJ Web of Conferences ◽

10.1051/epjconf/201919901024 ◽

2019 ◽

Vol 199 ◽

pp. 01024

Author(s):

I. Ciepał ◽

W. Przygoda ◽

A. V. Sarantsev

Keyword(s):

Partial Wave ◽

Pion Production ◽

Meson Production ◽

Resonance Region ◽

Partial Wave Analysis ◽

Wave Analysis ◽

Final State ◽

Hades Collaboration ◽

Pion Nucleon

Pion beams are perfect tools to probe resonance excitations at a fixed energy, thus properties of baryonic resonances and their coupling channels can be studied. The HADES Collaboration performed a systematic scan around the second resonance region at four different pion beam momenta 0.656, 0.69, 0.748 and 0.8 GeV/c in π− p reaction. The role of the N(1520) resonance in conjunction with the intermediate ρ-meson production has been studied in the framework of a partial wave analysis. Preliminary results on exclusive channels with one pion (π− p) and two pions (nπ+π− and pπ−π0) in the final state are presented.

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Bonding and stability in the ordered alloys FeV and CoTi. Comparison with FeTi

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19852093 ◽

1985 ◽

Vol 50 (10) ◽

pp. 2093-2100

Author(s):

Štěpán Pick ◽

Mojmír Tomášek ◽

Mojmír Šob

Keyword(s):

Phase Diagrams ◽

Partial Wave ◽

Partial Wave Analysis ◽

Intermetallic Alloys ◽

Wave Analysis ◽

Ordered Alloys ◽

Ordered Intermetallic ◽

Cscl Structure ◽

Ionic Effects

Partial wave analysis together with the qualitative examination of hybridization has been performed for two ordered intermetallic alloys with CsCl structure, FeV, and CoTi. The results resemble those obtained previously for FeTi, although important deviations are present as well. The stabilization of the ordered phase is again due to ionic effects. Qualitative arguments are suggested to explain the small stability of the CsCl phase of FeV and some differences in the FeTi and CoTi phase diagrams.

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