News from the light and strange meson sector


  • Stefan Wallner Technische Universitaet Muenchen (DE)



hadron spectroscopy, GlueX, COMPASS, LHCb, BESIII, JPAC, HadSpec, partial-wave analysis, non-resonant processes, lattice QCD, light mesons, strange mesons, exotics


Recent high-quality data sets from various experiments grant new insights into the excitation spectrum of light mesons, which are composed of up, down, and strange quarks. In the non-strange light-meson sector, many recent experimental and theory efforts are focused on the search for so-called exotic states, which are states beyond the na¨ıve constituent quark-model. To this end, various potential decay modes of exotic states are studied at experiments such as GlueX or COMPASS. In addition, there is recent progress in the understanding of so-called non-resonant processes, which act as background in searches for light mesons, as well as in the prediction of light mesons from lattice QCD. While the non-strange light-meson spectrum is already mapped out rather well, many predicted strange mesons have not yet been observed experimentally or need further confirmation. Recent high-precision data from experiments such as LHCb and BESIII allow us to study strange mesons in heavy-meson decays. Alternatively, strange mesons are studied in diffractive scattering of high-energy kaon beams. The so far world’s largest data set on the diffractively produced K−π −π + final state was measured by the COMPASS experiment. A recent analysis of this data covers a large variety of strange mesons over a wide mass range in a single, self-consistent analysis


M. G. Alexeev et al., [COMPASS], Exotic meson π1(1600) with J P C = 1−+ and its decay into ρ(770)π, (2021),

J. Dudek et al., [HadSpec], Toward the excited isoscalar meson spectrum from lattice QCD, Phys. Rev. D 88 (2013) 094505,

A. Austregesilo, [GlueX], Exploring the Hadron Spectrum with GlueX, JLUO Group Meeting, Wednesday June 24 2020,

P. Pauli, [GlueX], Accessing glue through photoproduction measurements at GlueX, Hadron2021, Mexico, within these proceedings.

M. Aghasyan et al., [COMPASS], Light isovector resonances in π −p → π −π −π +p at 190 GeV/c, Phys. Rev. D 98 (2018) 092003,

L. Bibrzycki et al., [JPAC], π −p → η ( 0 )π −p in the doubleRegge region, Eur. Phys. J. C 81 (2021) 647,

B. Kopf et al., Investigation of the lightest hybrid meson candidate with a coupled-channel analysis of pp¯ -, π −p- and ππData, Eur. Phys. J. C 81 (2021) 1056,

A. Rodas et al., [JPAC], Determination of the Pole Position of the Lightest Hybrid Meson Candidate, Phys. Rev. Lett. 122 (2019) 042002,

A. J. Woss et al., [HadSpec], Decays of an exotic 1 −+ hybrid meson resonance in QCD, Phys. Rev. D 103 (2021) 54502,

M. Lu et al., [E852], Exotic meson decay to ωπ0π −, Phys. Rev. Lett. 94 (2005) 032002,

C. A. Baker et al., Confirmation of a0(1450) and π1(1600) in pp¯ → ωπ+π −π 0 at rest, Phys. Lett. B 563 (2003) 140,

F. M. Kaspar and S. Gerassimov, [COMPASS], Analysis of the Diffractively Produced π −π −π + Final State at COMPASS, Hadron2021, Mexico, within these proceedings.

P. A. Zyla et al., [PDG], Review of Particle Physics 2021 update, Prog. Theor. Exp. Phys. 2020 (2021) 083C01,

D. Ebert, R. N. Faustov, and V. O. Galkin, Mass spectra and Regge trajectories of light mesons in the relativistic quark model, Phys. Rev. D 79 (2009) 114029,

S. Wallner, [COMPASS], Strange-Meson Spectroscopy at COMPASS, HADRON2019, Guilin, China, 2020, 134,

S. Wallner, Exploring the Strange-Meson Spectrum with COMPASS in the Reaction K− + p → K−π −π + + p, Ph.D. thesis: Technical University of Munich, 2022.

C. Daum et al., [ACCMOR], Diffractive production of strange mesons at 63 GeV, Nucl. Phys. B 187 (1981) 1,

M. Ablikim et al., [BESIII], Partial wave analysis of J/ψ → K+K−π 0 , Phys. Rev. D 100 (2019) 032004,

M. Ablikim et al., [BESIII], Partial wave analysis of ψ(3686) → K+K−η, Phys. Rev. D 101 (2020) 032008, 032008.

R. Aaij et al., [LHCb], Observation of J/ψφ Structures Consistent with Exotic States from Amplitude Analysis of B + → J/ψφK+ Decays, Phys. Rev. Lett. 118 (2017) 022003,

R. Aaij et al., [LHCb], Observation of New Resonances Decaying to J/ψK+ and J/ψφ, Phys. Rev. Lett. 127 (2021) 082001,

V. M. Karnaukhov, V. I. Moroz, and C. Coca, A Narrow Structure with M = 1.63 GeV/c2 in the Mass Spectrum of KSπ +π − System, Phys. Atom. Nucl. 61 (1998) 203.

B. Adams et al., [AMBER], Letter of Intent: A New QCD facility at the M2 beam line of the CERN SPS (COMPASS++/AMBER), (2018), arXiv:




How to Cite

Wallner S. News from the light and strange meson sector. Supl. Rev. Mex. Fis. [Internet]. 2022 May 19 [cited 2024 May 20];3(3):0308004 1-7. Available from: