Analysis of the diffractively produced π −π −π + final state at COMPASS


  • Florian Markus Kaspar Technische Universität München
  • Sergei Gerassimov Technische Universität München



COMPASS, partial-wave analysis, PWA, pi(1800), hybrid, diffraction, light mesons, resonance, meson spectroscopy


The COMPASS experiment at CERN collected a large sample of diffractively produced π −π −π + events. The data contain contributions from light-meson resonances with the quantum numbers of πJ - and aJ -like states. We performed a partial-wave analysis of this final state for proton and nuclear targets. We consistently observe a π-like signal with J P C = 0−+ in the f2(1270)πD wave. The signal appears to be incompatible with the established π(1800) resonance, which we observe in the decays into (ππ)SπS, f0(980)πS and f0(1500)πS waves.


D. V. Amelin et al. [VES Collaboration], Study of resonance production in diffractive reaction $ensuremath{pi^- A to pi^+ pi^- pi^- A}$, Phys. Lett. B {bf356} (1995) 595, url{}

D. V. Amelin et al. [VES Collaboration], Study of the reaction $ensuremath{pi^- Be to omega pi^- pi^0 Be}$, arXiv (1998), preprint available at url{}

P. A. Zyla et al. [Particle Data Group], Review of Particle Physics {bf2020} (2020) 083C01, url{}

F. E. Close and P. R. Page, Distinguishing hybrids from radial quarkonia, Phys. Rev. D {bf56} (1997) 1584, url{}

C. Adolph et al. [COMPASS Collaboration], Resonance production and $ensuremath{pi}ensuremath{pi}$ $S$-wave in ${ensuremath{pi}}^{ensuremath{-}}+pensuremath{rightarrow}{ensuremath{pi}}^{ensuremath{-}}{ensuremath{pi}}^{ensuremath{-}}{ensuremath{pi}}^{+}+{p}_{mathbf{text{recoil}}}$ at $190text{ }text{ }mathrm{GeV}/c$, Phys. Rev. D {bf95} (2017) 032004, url{}

M. Aghasyan et al. [COMPASS Collaboration], Light isovector resonances in ${ensuremath{pi}}^{ensuremath{-}}pensuremath{rightarrow}{ensuremath{pi}}^{ensuremath{-}}{ensuremath{pi}}^{ensuremath{-}}{ensuremath{pi}}^{+}p$ at $190text{ }text{ }mathrm{GeV}/c$, Phys. Rev. D {bf98} (2018) 092003, url{}

F. Haas, Two-Dimensional Partial-Wave Analysis of Exclusive 190,GeV $pi^- p$ Scattering into the $pi^-pi^-pi^+$ Final State at COMPASS (CERN), PhD thesis (2014), url{}

R. T. Deck, Kinematical Interpretation of the First $ensuremath{pi}ensuremath{-}p$ Resonance, Phys. Rev. Lett. {bf13} (1964) 169, url{}

A. B. Kaidalov, Diffractive production mechanisms, Physics Reports {bf{50}} (1979) 157, url{}




How to Cite

Kaspar FM, Gerassimov S. Analysis of the diffractively produced π −π −π + final state at COMPASS. Supl. Rev. Mex. Fis. [Internet]. 2022 Jun. 10 [cited 2024 May 29];3(3):0308020 1-5. Available from: