Physics Letters B (Jul 2017)

Measurement of the ω→π+π−π0 Dalitz plot distribution

  • P. Adlarson,
  • W. Augustyniak,
  • W. Bardan,
  • M. Bashkanov,
  • F.S. Bergmann,
  • M. Berłowski,
  • H. Bhatt,
  • A. Bondar,
  • M. Büscher,
  • H. Calén,
  • I. Ciepał,
  • H. Clement,
  • E. Czerwiński,
  • K. Demmich,
  • R. Engels,
  • A. Erven,
  • W. Erven,
  • W. Eyrich,
  • P. Fedorets,
  • K. Föhl,
  • K. Fransson,
  • F. Goldenbaum,
  • A. Goswami,
  • K. Grigoryev,
  • C.-O. Gullström,
  • L. Heijkenskjöld,
  • V. Hejny,
  • N. Hüsken,
  • L. Jarczyk,
  • T. Johansson,
  • B. Kamys,
  • G. Kemmerling,
  • F.A. Khan,
  • G. Khatri,
  • A. Khoukaz,
  • O. Khreptak,
  • D.A. Kirillov,
  • S. Kistryn,
  • H. Kleines,
  • B. Kłos,
  • W. Krzemień,
  • P. Kulessa,
  • A. Kupść,
  • A. Kuzmin,
  • K. Lalwani,
  • D. Lersch,
  • B. Lorentz,
  • A. Magiera,
  • R. Maier,
  • P. Marciniewski,
  • B. Mariański,
  • H.-P. Morsch,
  • P. Moskal,
  • H. Ohm,
  • E. Perez del Rio,
  • N.M. Piskunov,
  • D. Prasuhn,
  • D. Pszczel,
  • K. Pysz,
  • A. Pyszniak,
  • J. Ritman,
  • A. Roy,
  • Z. Rudy,
  • O. Rundel,
  • S. Sawant,
  • S. Schadmand,
  • I. Schätti-Ozerianska,
  • T. Sefzick,
  • V. Serdyuk,
  • B. Shwartz,
  • K. Sitterberg,
  • T. Skorodko,
  • M. Skurzok,
  • J. Smyrski,
  • V. Sopov,
  • R. Stassen,
  • J. Stepaniak,
  • E. Stephan,
  • G. Sterzenbach,
  • H. Stockhorst,
  • H. Ströher,
  • A. Szczurek,
  • A. Trzciński,
  • R. Varma,
  • M. Wolke,
  • A. Wrońska,
  • P. Wüstner,
  • A. Yamamoto,
  • J. Zabierowski,
  • M.J. Zieliński,
  • J. Złomańczuk,
  • P. Żuprański,
  • M. Żurek

DOI
https://doi.org/10.1016/j.physletb.2017.03.050
Journal volume & issue
Vol. 770, no. C
pp. 418 – 425

Abstract

Read online

Using the production reactions pd→He3ω and pp→ppω, the Dalitz plot distribution for the ω→π+π−π0 decay is studied with the WASA detector at COSY, based on a combined data sample of (4.408±0.042)×104 events. The Dalitz plot density is parametrised by a product of the P-wave phase space and a polynomial expansion in the normalised polar Dalitz plot variables Z and ϕ. For the first time, a deviation from pure P-wave phase space is observed with a significance of 4.1σ. The deviation is parametrised by a linear term 1+2αZ, with α determined to be +0.147±0.036, consistent with the expectations of ρ-meson-type final-state interactions of the P-wave pion pairs.

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