Triangle Singularity as the Origin of the a1 (1420)

G. D. Alexeev; M. G. Alexeev; A. Amoroso; V. Andrieux; V. Anosov; A. Antoshkin; K. Augsten; W. Augustyniak; C. D.R. Azevedo; B. Badełek; F. Balestra; M. Ball; J. Barth; R. Beck; Y. Bedfer; J. Berenguer Antequera; J. Bernhard; M. Bodlak; F. Bradamante; A. Bressan; V. E. Burtsev; W. C. Chang; C. Chatterjee; M. Chiosso; A. G. Chumakov; S. U. Chung; A. Cicuttin; P. M.M. Correia; M. L. Crespo; D. D'Ago; S. Dalla Torre; S. S. Dasgupta; S. Dasgupta; I. Denisenko; O. Yu Denisov; S. V. Donskov; N. Doshita; Ch Dreisbach; W. Dünnweber; R. R. Dusaev; A. Efremov; P. D. Eversheim; P. Faccioli; M. Faessler; M. Finger; M. Finger; H. Fischer; C. Franco; J. M. Friedrich; V. Frolov; F. Gautheron; O. P. Gavrichtchouk; S. Gerassimov; J. Giarra; I. Gnesi; M. Gorzellik; A. Grasso; A. Gridin; M. Grosse Perdekamp; B. Grube; A. Guskov; D. Von Harrach; R. Heitz; F. Herrmann; N. Horikawa; N. D'Hose; C. Y. Hsieh; S. Huber; S. Ishimoto; A. Ivanov; T. Iwata; M. Jandek; V. Jary; R. Joosten; P. Jörg; E. Kabuß; F. Kaspar; A. Kerbizi; B. Ketzer; G. V. Khaustov; Yu A. Khokhlov; Yu Kisselev; F. Klein; J. H. Koivuniemi; V. N. Kolosov; K. Kondo Horikawa; I. Konorov; V. F. Konstantinov; A. M. Kotzinian; O. M. Kouznetsov; A. Koval; Z. Kral; F. Krinner; Y. Kulinich; F. Kunne; K. Kurek; R. P. Kurjata; A. Kveton; K. Lavickova; S. Levorato; Y. S. Lian; J. Lichtenstadt; P. J. Lin; R. Longo; V. E. Lyubovitskij; A. Maggiora; A. Magnon; N. Makins; N. Makke; G. K. Mallot; A. Maltsev; S. A. Mamon; B. Marianski; A. Martin; J. Marzec; J. Matoušek; T. Matsuda; G. Mattson; G. V. Meshcheryakov; M. Meyer; W. Meyer; Yu V. Mikhailov; M. Mikhasenko; E. Mitrofanov; N. Mitrofanov; Y. Miyachi; A. Moretti; A. Nagaytsev; C. Naim; D. Neyret; J. Nový; W. D. Nowak; G. Nukazuka; A. S. Nunes; A. G. Olshevsky; M. Ostrick; D. Panzieri; B. Parsamyan; S. Paul; H. Pekeler; J. C. Peng; M. Pešek; D. V. Peshekhonov; M. Pešková; N. Pierre; S. Platchkov; J. Pochodzalla; V. A. Polyakov; J. Pretz; M. Quaresma; C. Quintans; G. Reicherz; C. Riedl; T. Rudnicki; D. I. Ryabchikov; A. Rybnikov; A. Rychter; V. D. Samoylenko; A. Sandacz; S. Sarkar; I. A. Savin; G. Sbrizzai; H. Schmieden; A. Selyunin; L. Sinha; M. Slunecka; J. Smolik; A. Srnka; D. Steffen; M. Stolarski; O. Subrt; M. Sulc; H. Suzuki; P. Sznajder; S. Tessaro; F. Tessarotto; A. Thiel; J. Tomsa; F. Tosello; A. Townsend; V. Tskhay; S. Uhl; B. I. Vasilishin; A. Vauth; B. M. Veit; J. Veloso; B. Ventura; A. Vidon; M. Virius; M. Wagner; S. Wallner; K. Zaremba; P. Zavada; M. Zavertyaev; M. Zemko; E. Zemlyanichkina; Y. Zhao; M. Ziembicki

doi:10.1103/PhysRevLett.127.082501

Triangle Singularity as the Origin of the a1 (1420)

G. D. Alexeev, M. G. Alexeev, A. Amoroso, V. Andrieux, V. Anosov, A. Antoshkin, K. Augsten, W. Augustyniak, C. D.R. Azevedo, B. Badełek, F. Balestra, M. Ball, J. Barth, R. Beck, Y. Bedfer, J. Berenguer Antequera, J. Bernhard, M. Bodlak, F. Bradamante, A. BressanV. E. Burtsev, W. C. Chang, C. Chatterjee, M. Chiosso, A. G. Chumakov, S. U. Chung, A. Cicuttin, P. M.M. Correia, M. L. Crespo, D. D'Ago, S. Dalla Torre, S. S. Dasgupta, S. Dasgupta, I. Denisenko, O. Yu Denisov, S. V. Donskov, N. Doshita, Ch Dreisbach, W. Dünnweber, R. R. Dusaev, A. Efremov, P. D. Eversheim, P. Faccioli, M. Faessler, M. Finger, M. Finger, H. Fischer, C. Franco, J. M. Friedrich, V. Frolov, F. Gautheron, O. P. Gavrichtchouk, S. Gerassimov, J. Giarra, I. Gnesi, M. Gorzellik, A. Grasso, A. Gridin, M. Grosse Perdekamp, B. Grube, A. Guskov, D. Von Harrach, R. Heitz, F. Herrmann, N. Horikawa, N. D'Hose, C. Y. Hsieh, S. Huber, S. Ishimoto, A. Ivanov, T. Iwata, M. Jandek, V. Jary, R. Joosten, P. Jörg, E. Kabuß, F. Kaspar, A. Kerbizi, B. Ketzer, G. V. Khaustov, Yu A. Khokhlov, Yu Kisselev, F. Klein, J. H. Koivuniemi, V. N. Kolosov, K. Kondo Horikawa, I. Konorov, V. F. Konstantinov, A. M. Kotzinian, O. M. Kouznetsov, A. Koval, Z. Kral, F. Krinner, Y. Kulinich, F. Kunne, K. Kurek, R. P. Kurjata, A. Kveton, K. Lavickova, S. Levorato, Y. S. Lian, J. Lichtenstadt, P. J. Lin, R. Longo, V. E. Lyubovitskij, A. Maggiora, A. Magnon, N. Makins, N. Makke, G. K. Mallot, A. Maltsev, S. A. Mamon, B. Marianski, A. Martin, J. Marzec, J. Matoušek, T. Matsuda, G. Mattson, G. V. Meshcheryakov, M. Meyer, W. Meyer, Yu V. Mikhailov, M. Mikhasenko, E. Mitrofanov, N. Mitrofanov, Y. Miyachi, A. Moretti, A. Nagaytsev, C. Naim, D. Neyret, J. Nový, W. D. Nowak, G. Nukazuka, A. S. Nunes, A. G. Olshevsky, M. Ostrick, D. Panzieri, B. Parsamyan, S. Paul, H. Pekeler, J. C. Peng, M. Pešek, D. V. Peshekhonov, M. Pešková, N. Pierre, S. Platchkov, J. Pochodzalla, V. A. Polyakov, J. Pretz, M. Quaresma, C. Quintans, G. Reicherz, C. Riedl, T. Rudnicki, D. I. Ryabchikov, A. Rybnikov, A. Rychter, V. D. Samoylenko, A. Sandacz, S. Sarkar, I. A. Savin, G. Sbrizzai, H. Schmieden, A. Selyunin, L. Sinha, M. Slunecka, J. Smolik, A. Srnka, D. Steffen, M. Stolarski, O. Subrt, M. Sulc, H. Suzuki, P. Sznajder, S. Tessaro, F. Tessarotto, A. Thiel, J. Tomsa, F. Tosello, A. Townsend, V. Tskhay, S. Uhl, B. I. Vasilishin, A. Vauth, B. M. Veit, J. Veloso, B. Ventura, A. Vidon, M. Virius, M. Wagner, S. Wallner, K. Zaremba, P. Zavada, M. Zavertyaev, M. Zemko, E. Zemlyanichkina, Y. Zhao, M. Ziembicki

Risultato della ricerca: Contributo su rivista › Articolo in rivista › peer review

Abstract

The COMPASS Collaboration experiment recently discovered a new isovector resonancelike signal with axial-vector quantum numbers, the a1(1420), decaying to f0(980)π. With a mass too close to and a width smaller than the axial-vector ground state a1(1260), it was immediately interpreted as a new light exotic meson, similar to the X, Y, Z states in the hidden-charm sector. We show that a resonancelike signal fully matching the experimental data is produced by the decay of the a1(1260) resonance into K∗(→Kπ)K̄ and subsequent rescattering through a triangle singularity into the coupled f0(980)π channel. The amplitude for this process is calculated using a new approach based on dispersion relations. The triangle-singularity model is fitted to the partial-wave data of the COMPASS experiment. Despite having fewer parameters, this fit shows a slightly better quality than the one using a resonance hypothesis and thus eliminates the need for an additional resonance in order to describe the data. We thereby demonstrate for the first time in the light-meson sector that a resonancelike structure in the experimental data can be described by rescattering through a triangle singularity, providing evidence for a genuine three-body effect.

Lingua originale	Inglese
Numero di articolo	082501
Rivista	Physical Review Letters
Volume	127
Numero di pubblicazione	8
DOI	https://doi.org/10.1103/PhysRevLett.127.082501
Stato di pubblicazione	Pubblicato - 20 ago 2021
Pubblicato esternamente	Sì

Accesso al documento

10.1103/PhysRevLett.127.082501

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Cita questo

Alexeev, G. D., Alexeev, M. G., Amoroso, A., Andrieux, V., Anosov, V., Antoshkin, A., Augsten, K., Augustyniak, W., Azevedo, C. D. R., Badełek, B., Balestra, F., Ball, M., Barth, J., Beck, R., Bedfer, Y., Berenguer Antequera, J., Bernhard, J., Bodlak, M., Bradamante, F., ... Ziembicki, M. (2021). Triangle Singularity as the Origin of the a1 (1420). Physical Review Letters, 127(8), Articolo 082501. https://doi.org/10.1103/PhysRevLett.127.082501

@article{497097de01b14c278f9f32374a569b8d,

title = "Triangle Singularity as the Origin of the a1 (1420)",

abstract = "The COMPASS Collaboration experiment recently discovered a new isovector resonancelike signal with axial-vector quantum numbers, the a1(1420), decaying to f0(980)π. With a mass too close to and a width smaller than the axial-vector ground state a1(1260), it was immediately interpreted as a new light exotic meson, similar to the X, Y, Z states in the hidden-charm sector. We show that a resonancelike signal fully matching the experimental data is produced by the decay of the a1(1260) resonance into K∗(→Kπ){\=K} and subsequent rescattering through a triangle singularity into the coupled f0(980)π channel. The amplitude for this process is calculated using a new approach based on dispersion relations. The triangle-singularity model is fitted to the partial-wave data of the COMPASS experiment. Despite having fewer parameters, this fit shows a slightly better quality than the one using a resonance hypothesis and thus eliminates the need for an additional resonance in order to describe the data. We thereby demonstrate for the first time in the light-meson sector that a resonancelike structure in the experimental data can be described by rescattering through a triangle singularity, providing evidence for a genuine three-body effect.",

author = "Alexeev, \{G. D.\} and Alexeev, \{M. G.\} and A. Amoroso and V. Andrieux and V. Anosov and A. Antoshkin and K. Augsten and W. Augustyniak and Azevedo, \{C. D.R.\} and B. Bade{\l}ek and F. Balestra and M. Ball and J. Barth and R. Beck and Y. Bedfer and \{Berenguer Antequera\}, J. and J. Bernhard and M. Bodlak and F. Bradamante and A. Bressan and Burtsev, \{V. E.\} and Chang, \{W. C.\} and C. Chatterjee and M. Chiosso and Chumakov, \{A. G.\} and Chung, \{S. U.\} and A. Cicuttin and Correia, \{P. M.M.\} and Crespo, \{M. L.\} and D. D'Ago and \{Dalla Torre\}, S. and Dasgupta, \{S. S.\} and S. Dasgupta and I. Denisenko and Denisov, \{O. Yu\} and Donskov, \{S. V.\} and N. Doshita and Ch Dreisbach and W. D{\"u}nnweber and Dusaev, \{R. R.\} and A. Efremov and Eversheim, \{P. D.\} and P. Faccioli and M. Faessler and M. Finger and M. Finger and H. Fischer and C. Franco and Friedrich, \{J. M.\} and V. Frolov and F. Gautheron and Gavrichtchouk, \{O. P.\} and S. Gerassimov and J. Giarra and I. Gnesi and M. Gorzellik and A. Grasso and A. Gridin and \{Grosse Perdekamp\}, M. and B. Grube and A. Guskov and \{Von Harrach\}, D. and R. Heitz and F. Herrmann and N. Horikawa and N. D'Hose and Hsieh, \{C. Y.\} and S. Huber and S. Ishimoto and A. Ivanov and T. Iwata and M. Jandek and V. Jary and R. Joosten and P. J{\"o}rg and E. Kabu{\ss} and F. Kaspar and A. Kerbizi and B. Ketzer and Khaustov, \{G. V.\} and Khokhlov, \{Yu A.\} and Yu Kisselev and F. Klein and Koivuniemi, \{J. H.\} and Kolosov, \{V. N.\} and \{Kondo Horikawa\}, K. and I. Konorov and Konstantinov, \{V. F.\} and Kotzinian, \{A. M.\} and Kouznetsov, \{O. M.\} and A. Koval and Z. Kral and F. Krinner and Y. Kulinich and F. Kunne and K. Kurek and Kurjata, \{R. P.\} and A. Kveton and K. Lavickova and S. Levorato and Lian, \{Y. S.\} and J. Lichtenstadt and Lin, \{P. J.\} and R. Longo and Lyubovitskij, \{V. E.\} and A. Maggiora and A. Magnon and N. Makins and N. Makke and Mallot, \{G. K.\} and A. Maltsev and Mamon, \{S. A.\} and B. Marianski and A. Martin and J. Marzec and J. Matou{\v s}ek and T. Matsuda and G. Mattson and Meshcheryakov, \{G. V.\} and M. Meyer and W. Meyer and Mikhailov, \{Yu V.\} and M. Mikhasenko and E. Mitrofanov and N. Mitrofanov and Y. Miyachi and A. Moretti and A. Nagaytsev and C. Naim and D. Neyret and J. Nov{\'y} and Nowak, \{W. D.\} and G. Nukazuka and Nunes, \{A. S.\} and Olshevsky, \{A. G.\} and M. Ostrick and D. Panzieri and B. Parsamyan and S. Paul and H. Pekeler and Peng, \{J. C.\} and M. Pe{\v s}ek and Peshekhonov, \{D. V.\} and M. Pe{\v s}kov{\'a} and N. Pierre and S. Platchkov and J. Pochodzalla and Polyakov, \{V. A.\} and J. Pretz and M. Quaresma and C. Quintans and G. Reicherz and C. Riedl and T. Rudnicki and Ryabchikov, \{D. I.\} and A. Rybnikov and A. Rychter and Samoylenko, \{V. D.\} and A. Sandacz and S. Sarkar and Savin, \{I. A.\} and G. Sbrizzai and H. Schmieden and A. Selyunin and L. Sinha and M. Slunecka and J. Smolik and A. Srnka and D. Steffen and M. Stolarski and O. Subrt and M. Sulc and H. Suzuki and P. Sznajder and S. Tessaro and F. Tessarotto and A. Thiel and J. Tomsa and F. Tosello and A. Townsend and V. Tskhay and S. Uhl and Vasilishin, \{B. I.\} and A. Vauth and Veit, \{B. M.\} and J. Veloso and B. Ventura and A. Vidon and M. Virius and M. Wagner and S. Wallner and K. Zaremba and P. Zavada and M. Zavertyaev and M. Zemko and E. Zemlyanichkina and Y. Zhao and M. Ziembicki",

note = "Publisher Copyright: {\textcopyright} 2021 authors. Published by the American Physical Society.",

year = "2021",

month = aug,

day = "20",

doi = "10.1103/PhysRevLett.127.082501",

language = "English",

volume = "127",

journal = "Physical Review Letters",

issn = "0031-9007",

publisher = "American Physical Society",

number = "8",

}

Alexeev, GD, Alexeev, MG, Amoroso, A, Andrieux, V, Anosov, V, Antoshkin, A, Augsten, K, Augustyniak, W, Azevedo, CDR, Badełek, B, Balestra, F, Ball, M, Barth, J, Beck, R, Bedfer, Y, Berenguer Antequera, J, Bernhard, J, Bodlak, M, Bradamante, F, Bressan, A, Burtsev, VE, Chang, WC, Chatterjee, C, Chiosso, M, Chumakov, AG, Chung, SU, Cicuttin, A, Correia, PMM, Crespo, ML, D'Ago, D, Dalla Torre, S, Dasgupta, SS, Dasgupta, S, Denisenko, I, Denisov, OY, Donskov, SV, Doshita, N, Dreisbach, C, Dünnweber, W, Dusaev, RR, Efremov, A, Eversheim, PD, Faccioli, P, Faessler, M, Finger, M, Finger, M, Fischer, H, Franco, C, Friedrich, JM, Frolov, V, Gautheron, F, Gavrichtchouk, OP, Gerassimov, S, Giarra, J, Gnesi, I, Gorzellik, M, Grasso, A, Gridin, A, Grosse Perdekamp, M, Grube, B, Guskov, A, Von Harrach, D, Heitz, R, Herrmann, F, Horikawa, N, D'Hose, N, Hsieh, CY, Huber, S, Ishimoto, S, Ivanov, A, Iwata, T, Jandek, M, Jary, V, Joosten, R, Jörg, P, Kabuß, E, Kaspar, F, Kerbizi, A, Ketzer, B, Khaustov, GV, Khokhlov, YA, Kisselev, Y, Klein, F, Koivuniemi, JH, Kolosov, VN, Kondo Horikawa, K, Konorov, I, Konstantinov, VF, Kotzinian, AM, Kouznetsov, OM, Koval, A, Kral, Z, Krinner, F, Kulinich, Y, Kunne, F, Kurek, K, Kurjata, RP, Kveton, A, Lavickova, K, Levorato, S, Lian, YS, Lichtenstadt, J, Lin, PJ, Longo, R, Lyubovitskij, VE, Maggiora, A, Magnon, A, Makins, N, Makke, N, Mallot, GK, Maltsev, A, Mamon, SA, Marianski, B, Martin, A, Marzec, J, Matoušek, J, Matsuda, T, Mattson, G, Meshcheryakov, GV, Meyer, M, Meyer, W, Mikhailov, YV, Mikhasenko, M, Mitrofanov, E, Mitrofanov, N, Miyachi, Y, Moretti, A, Nagaytsev, A, Naim, C, Neyret, D, Nový, J, Nowak, WD, Nukazuka, G, Nunes, AS, Olshevsky, AG, Ostrick, M, Panzieri, D, Parsamyan, B, Paul, S, Pekeler, H, Peng, JC, Pešek, M, Peshekhonov, DV, Pešková, M, Pierre, N, Platchkov, S, Pochodzalla, J, Polyakov, VA, Pretz, J, Quaresma, M, Quintans, C, Reicherz, G, Riedl, C, Rudnicki, T, Ryabchikov, DI, Rybnikov, A, Rychter, A, Samoylenko, VD, Sandacz, A, Sarkar, S, Savin, IA, Sbrizzai, G, Schmieden, H, Selyunin, A, Sinha, L, Slunecka, M, Smolik, J, Srnka, A, Steffen, D, Stolarski, M, Subrt, O, Sulc, M, Suzuki, H, Sznajder, P, Tessaro, S, Tessarotto, F, Thiel, A, Tomsa, J, Tosello, F, Townsend, A, Tskhay, V, Uhl, S, Vasilishin, BI, Vauth, A, Veit, BM, Veloso, J, Ventura, B, Vidon, A, Virius, M, Wagner, M, Wallner, S, Zaremba, K, Zavada, P, Zavertyaev, M, Zemko, M, Zemlyanichkina, E, Zhao, Y & Ziembicki, M 2021, 'Triangle Singularity as the Origin of the a1 (1420)', Physical Review Letters, vol. 127, n. 8, 082501. https://doi.org/10.1103/PhysRevLett.127.082501

TY - JOUR

T1 - Triangle Singularity as the Origin of the a1 (1420)

AU - Alexeev, G. D.

AU - Alexeev, M. G.

AU - Amoroso, A.

AU - Andrieux, V.

AU - Anosov, V.

AU - Antoshkin, A.

AU - Augsten, K.

AU - Augustyniak, W.

AU - Azevedo, C. D.R.

AU - Badełek, B.

AU - Balestra, F.

AU - Ball, M.

AU - Barth, J.

AU - Beck, R.

AU - Bedfer, Y.

AU - Berenguer Antequera, J.

AU - Bernhard, J.

AU - Bodlak, M.

AU - Bradamante, F.

AU - Bressan, A.

AU - Burtsev, V. E.

AU - Chang, W. C.

AU - Chatterjee, C.

AU - Chiosso, M.

AU - Chumakov, A. G.

AU - Chung, S. U.

AU - Cicuttin, A.

AU - Correia, P. M.M.

AU - Crespo, M. L.

AU - D'Ago, D.

AU - Dalla Torre, S.

AU - Dasgupta, S. S.

AU - Dasgupta, S.

AU - Denisenko, I.

AU - Denisov, O. Yu

AU - Donskov, S. V.

AU - Doshita, N.

AU - Dreisbach, Ch

AU - Dünnweber, W.

AU - Dusaev, R. R.

AU - Efremov, A.

AU - Eversheim, P. D.

AU - Faccioli, P.

AU - Faessler, M.

AU - Finger, M.

AU - Fischer, H.

AU - Franco, C.

AU - Friedrich, J. M.

AU - Frolov, V.

AU - Gautheron, F.

AU - Gavrichtchouk, O. P.

AU - Gerassimov, S.

AU - Giarra, J.

AU - Gnesi, I.

AU - Gorzellik, M.

AU - Grasso, A.

AU - Gridin, A.

AU - Grosse Perdekamp, M.

AU - Grube, B.

AU - Guskov, A.

AU - Von Harrach, D.

AU - Heitz, R.

AU - Herrmann, F.

AU - Horikawa, N.

AU - D'Hose, N.

AU - Hsieh, C. Y.

AU - Huber, S.

AU - Ishimoto, S.

AU - Ivanov, A.

AU - Iwata, T.

AU - Jandek, M.

AU - Jary, V.

AU - Joosten, R.

AU - Jörg, P.

AU - Kabuß, E.

AU - Kaspar, F.

AU - Kerbizi, A.

AU - Ketzer, B.

AU - Khaustov, G. V.

AU - Khokhlov, Yu A.

AU - Kisselev, Yu

AU - Klein, F.

AU - Koivuniemi, J. H.

AU - Kolosov, V. N.

AU - Kondo Horikawa, K.

AU - Konorov, I.

AU - Konstantinov, V. F.

AU - Kotzinian, A. M.

AU - Kouznetsov, O. M.

AU - Koval, A.

AU - Kral, Z.

AU - Krinner, F.

AU - Kulinich, Y.

AU - Kunne, F.

AU - Kurek, K.

AU - Kurjata, R. P.

AU - Kveton, A.

AU - Lavickova, K.

AU - Levorato, S.

AU - Lian, Y. S.

AU - Lichtenstadt, J.

AU - Lin, P. J.

AU - Longo, R.

AU - Lyubovitskij, V. E.

AU - Maggiora, A.

AU - Magnon, A.

AU - Makins, N.

AU - Makke, N.

AU - Mallot, G. K.

AU - Maltsev, A.

AU - Mamon, S. A.

AU - Marianski, B.

AU - Martin, A.

AU - Marzec, J.

AU - Matoušek, J.

AU - Matsuda, T.

AU - Mattson, G.

AU - Meshcheryakov, G. V.

AU - Meyer, M.

AU - Meyer, W.

AU - Mikhailov, Yu V.

AU - Mikhasenko, M.

AU - Mitrofanov, E.

AU - Mitrofanov, N.

AU - Miyachi, Y.

AU - Moretti, A.

AU - Nagaytsev, A.

AU - Naim, C.

AU - Neyret, D.

AU - Nový, J.

AU - Nowak, W. D.

AU - Nukazuka, G.

AU - Nunes, A. S.

AU - Olshevsky, A. G.

AU - Ostrick, M.

AU - Panzieri, D.

AU - Parsamyan, B.

AU - Paul, S.

AU - Pekeler, H.

AU - Peng, J. C.

AU - Pešek, M.

AU - Peshekhonov, D. V.

AU - Pešková, M.

AU - Pierre, N.

AU - Platchkov, S.

AU - Pochodzalla, J.

AU - Polyakov, V. A.

AU - Pretz, J.

AU - Quaresma, M.

AU - Quintans, C.

AU - Reicherz, G.

AU - Riedl, C.

AU - Rudnicki, T.

AU - Ryabchikov, D. I.

AU - Rybnikov, A.

AU - Rychter, A.

AU - Samoylenko, V. D.

AU - Sandacz, A.

AU - Sarkar, S.

AU - Savin, I. A.

AU - Sbrizzai, G.

AU - Schmieden, H.

AU - Selyunin, A.

AU - Sinha, L.

AU - Slunecka, M.

AU - Smolik, J.

AU - Srnka, A.

AU - Steffen, D.

AU - Stolarski, M.

AU - Subrt, O.

AU - Sulc, M.

AU - Suzuki, H.

AU - Sznajder, P.

AU - Tessaro, S.

AU - Tessarotto, F.

AU - Thiel, A.

AU - Tomsa, J.

AU - Tosello, F.

AU - Townsend, A.

AU - Tskhay, V.

AU - Uhl, S.

AU - Vasilishin, B. I.

AU - Vauth, A.

AU - Veit, B. M.

AU - Veloso, J.

AU - Ventura, B.

AU - Vidon, A.

AU - Virius, M.

AU - Wagner, M.

AU - Wallner, S.

AU - Zaremba, K.

AU - Zavada, P.

AU - Zavertyaev, M.

AU - Zemko, M.

AU - Zemlyanichkina, E.

AU - Zhao, Y.

AU - Ziembicki, M.

PY - 2021/8/20

Y1 - 2021/8/20

N2 - The COMPASS Collaboration experiment recently discovered a new isovector resonancelike signal with axial-vector quantum numbers, the a1(1420), decaying to f0(980)π. With a mass too close to and a width smaller than the axial-vector ground state a1(1260), it was immediately interpreted as a new light exotic meson, similar to the X, Y, Z states in the hidden-charm sector. We show that a resonancelike signal fully matching the experimental data is produced by the decay of the a1(1260) resonance into K∗(→Kπ)K̄ and subsequent rescattering through a triangle singularity into the coupled f0(980)π channel. The amplitude for this process is calculated using a new approach based on dispersion relations. The triangle-singularity model is fitted to the partial-wave data of the COMPASS experiment. Despite having fewer parameters, this fit shows a slightly better quality than the one using a resonance hypothesis and thus eliminates the need for an additional resonance in order to describe the data. We thereby demonstrate for the first time in the light-meson sector that a resonancelike structure in the experimental data can be described by rescattering through a triangle singularity, providing evidence for a genuine three-body effect.

AB - The COMPASS Collaboration experiment recently discovered a new isovector resonancelike signal with axial-vector quantum numbers, the a1(1420), decaying to f0(980)π. With a mass too close to and a width smaller than the axial-vector ground state a1(1260), it was immediately interpreted as a new light exotic meson, similar to the X, Y, Z states in the hidden-charm sector. We show that a resonancelike signal fully matching the experimental data is produced by the decay of the a1(1260) resonance into K∗(→Kπ)K̄ and subsequent rescattering through a triangle singularity into the coupled f0(980)π channel. The amplitude for this process is calculated using a new approach based on dispersion relations. The triangle-singularity model is fitted to the partial-wave data of the COMPASS experiment. Despite having fewer parameters, this fit shows a slightly better quality than the one using a resonance hypothesis and thus eliminates the need for an additional resonance in order to describe the data. We thereby demonstrate for the first time in the light-meson sector that a resonancelike structure in the experimental data can be described by rescattering through a triangle singularity, providing evidence for a genuine three-body effect.

UR - https://www.scopus.com/pages/publications/85113660860

U2 - 10.1103/PhysRevLett.127.082501

DO - 10.1103/PhysRevLett.127.082501

M3 - Article

SN - 0031-9007

VL - 127

JO - Physical Review Letters

JF - Physical Review Letters

IS - 8

M1 - 082501

ER -

Triangle Singularity as the Origin of the a1 (1420)

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