The reaction π{sup −}p → π{sup −}π{sup −}π{sup +}p: Development of the analysis methods and selected results

Ryabchikov, D.

doi:10.1063/1.4938635

Title: The reaction π{sup −}p → π{sup −}π{sup −}π{sup +}p: Development of the analysis methods and selected results

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Abstract

We present the description of the analysis methods and results of applying them to the exclusive diffractive reaction π{sup −}p → π{sup −}π{sup −}π{sup +}p of 50 · 10{sup 6} events measured with COMPASS detector. The large statistics of π{sup −}π{sup −}π{sup +} events enables the two-dimensional partial-wave analysis independently in 100 bins of m(3π) with 0.5 < m(3π) < 2.5 GeV/c{sup 2} and in 11 intervals of squared momentum transfer with 0.1 < t′ < 1 GeV{sup 2}/c{sup 2}. The partial-wave analysis sub-density matrix is the subject to further mass-dependent fits describing the data in terms of resonances in 3π system and coherent background contributions. The novel approach of extracting J{sup PC} = 0{sup ++}(π{sup +}π{sup −}){sub S} isobar amplitudes as model-free functions, different for several J{sup PC} 3π states, is used. It demonstrates the presence of processes π(1800) → f{sub 0}(980)π and π(1800) → f{sub 0}(1500)π as well as π{sub 2}(1880) → f{sub 0}(980)π and new narrow signal a{sub 1}(1420) → f{sub 0}(980)π, without any established shapes used for (π{sup +}π{sup −}){sub S} isobars. The presented analysis is subject to further development and refinements which currently take place.

Authors:

Ryabchikov, D. ^[1]

Institute for High Energy Physics, Protvino (Russian Federation)

Publication Date:: Fri Jan 22 00:00:00 EST 2016

OSTI Identifier:: 22499042

Resource Type:: Journal Article

Journal Name:: AIP Conference Proceedings

Additional Journal Information:: Journal Volume: 1701; Journal Issue: 1; Conference: 11. conference on quark confinement and hadron spectrum, Saint Petersburg (Russian Federation), 8-12 Sep 2014; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0094-243X

Country of Publication:: United States

Language:: English

Subject:: 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLITUDES; COMPASS DETECTOR; DENSITY MATRIX; F0-980 MESONS; MASS; MOMENTUM TRANSFER; PARTIAL WAVES; SIGNALS; STATISTICS; TWO-DIMENSIONAL CALCULATIONS

Citation Formats


                    Ryabchikov, D. The reaction π{sup −}p → π{sup −}π{sup −}π{sup +}p: Development of the analysis methods and selected results.  United States: N. p., 2016. 
        Web.  doi:10.1063/1.4938635.

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                    Ryabchikov, D. The reaction π{sup −}p → π{sup −}π{sup −}π{sup +}p: Development of the analysis methods and selected results.  United States.  https://doi.org/10.1063/1.4938635

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                    Ryabchikov, D. 2016.  
        "The reaction π{sup −}p → π{sup −}π{sup −}π{sup +}p: Development of the analysis methods and selected results".  United States.  https://doi.org/10.1063/1.4938635.

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@article{osti_22499042,

  title        = {The reaction π{sup −}p → π{sup −}π{sup −}π{sup +}p: Development of the analysis methods and selected results},

  author       = {Ryabchikov, D.},

  abstractNote = {We present the description of the analysis methods and results of applying them to the exclusive diffractive reaction π{sup −}p → π{sup −}π{sup −}π{sup +}p of 50 · 10{sup 6} events measured with COMPASS detector. The large statistics of π{sup −}π{sup −}π{sup +} events enables the two-dimensional partial-wave analysis independently in 100 bins of m(3π) with 0.5 < m(3π) < 2.5 GeV/c{sup 2} and in 11 intervals of squared momentum transfer with 0.1 < t′ < 1 GeV{sup 2}/c{sup 2}. The partial-wave analysis sub-density matrix is the subject to further mass-dependent fits describing the data in terms of resonances in 3π system and coherent background contributions. The novel approach of extracting J{sup PC} = 0{sup ++}(π{sup +}π{sup −}){sub S} isobar amplitudes as model-free functions, different for several J{sup PC} 3π states, is used. It demonstrates the presence of processes π(1800) → f{sub 0}(980)π and π(1800) → f{sub 0}(1500)π as well as π{sub 2}(1880) → f{sub 0}(980)π and new narrow signal a{sub 1}(1420) → f{sub 0}(980)π, without any established shapes used for (π{sup +}π{sup −}){sub S} isobars. The presented analysis is subject to further development and refinements which currently take place.},

  doi          = {10.1063/1.4938635},

  url          = {https://www.osti.gov/biblio/22499042},
  journal      = {AIP Conference Proceedings},

  issn         = {0094-243X},

  number       = 1,

  volume       = 1701,

  place        = {United States},

  year         = {Fri Jan 22 00:00:00 EST 2016},

  month        = {Fri Jan 22 00:00:00 EST 2016}

}

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