학술논문

The exotic meson $\pi_1(1600)$ with $J^{PC} = 1^{-+}$ and its decay into $\rho(770)\pi$
Document Type
Working Paper
Author
Alexeev, M. G.Alexeev, G. D.Amoroso, A.Andrieux, V.Anosov, V.Augsten, K.Augustyniak, W.Azevedo, C. D. R.Badelek, B.Balestra, F.Ball, M.Barth, J.Beck, R.Bedfer, Y.Antequera, J. BerenguerBernhard, J.Bodlak, M.Bradamante, F.Bressan, A.Burtsev, V. E.Chang, W. -C.Chatterjee, C.Chiosso, M.Chumakov, A. G.Chung, S. -U.Cicuttin, A.Correia, P. M. M.Crespo, M. L.D'Ago, D.Torre, S. DallaDasgupta, S. S.Dasgupta, S.Denisenko, I.Denisov, O. Yu.Donskov, S. V.Doshita, N.Dreisbach, Ch.Duennweber, W.Dusaev, R. R.Efremov, A.Eremeev, D.Eversheim, P. D.Faccioli, P.Faessler, M.Finger, M.Finger jr., M.Fischer, H.Floethner, K.Franco, C.Friedrich, J. M.Frolov, V.Ordonez, L. G. GarciaGautheron, F.Gavrichtchouk, O. P.Gerassimov, S.Giarra, J.Giordano, D.Gorzellik, M.Grasso, A.Gridin, A.Perdekamp, M. GrosseGrube, B.Guskov, A.Haas, F.von Harrach, D.Hoffmann, M.Heitz, R.Horikawa, N.d'Hose, N.Hsieh, C. -Y.Huber, S.Ishimoto, S.Ivanov, A.Iwata, T.Jandek, M.Jary, T.Joosten, R.Kabuss, E.Kaspar, F.Kerbizi, A.Ketzer, B.Khaustov, G. V.Khokhlov, Yu. A.Kisselev, Yu.Klein, F.Koivuniemi, J. H.Kolosov, V. N.Konorov, I.Konstantinov, V. F.Kotzinian, A. M.Kouznetsov, O. M.Koval, A.Kral, Z.Krinner, F.Kulinich, Y.Kunne, F.Kurek, K.Kurjata, R. P.Kveton, A.Lavickova, K.Levorato, S.Lian, Y. -S.Lichtenstadt, J.Lin, P. -J.Longo, R.Lyubovitskij, V. E.Maggiora, A.Magnon, A.Makins, N.Makke, N.Mallot, G. K.Maltsev, A.Mamon, S. A.Marianski, B.Martin, A.Marzec, J.Matousek, J.Matsuda, T.Mattson, G.Metzger, F.Meyer, M.Meyer, W.Mikhailov, Yu. V.Mikhasenko, M.Mitrofanov, E.Miyachi, Y.Moretti, A.Nagaytsev, A.Naim, C.Neyret, D.Novy, J.Nowak, W. -D.Nukazuka, G.Olshevsky, A. G.Ostrick, M.Panzieri, D.Parsamyan, B.Paul, S.Pekeler, H.Peng, J. -C.Pesek, M.Peshekhonov, D. V.Peskova, M.Pierre, N.Platchkov, S.Pochodzalla, J.Polyakov, V. A.Pretz, J.Quaresma, M.Quintans, C.Reicherz, G.Riedl, C.Rudnicki, T.Ryabchikov, D. I.Rymbekova, A.Rychter, A.Samoylenko, V. D.Sandacz, A.Sarkar, S.Savin, I. A.Sbrizzai, G.Schmeing, S.Schmieden, H.Selyunin, A.Sharko, K.Sinha, L.Slunecka, M.Srnka, A.Steffen, D.Stolarski, M.Subrt, O.Sulc, M.Suzuki, H.Tessaro, S.Tessarotto, F.Thiel, A.Tomsa, J.Tosello, F.Townsend, A.Tskhay, V.Triloki, T.Uhl, S.Vauth, A.Veit, B. M.Veloso, J.Ventura, B.Vidon, A.Virius, M.Wagner, M.Wallner, S.Zaremba, K.Zavertyaev, M.Zemko, M.Zemlyanichkina, E.Zhao, Y.Ziembicki, M.
Source
Phys.Rev.D 105 (2022) 1, 012005
Subject
High Energy Physics - Experiment
High Energy Physics - Phenomenology
Language
Abstract
We study the spin-exotic $J^{PC} = 1^{-+}$ amplitude in single-diffractive dissociation of 190 GeV$/c$ pions into $\pi^-\pi^-\pi^+$ using a hydrogen target and confirm the $\pi_1(1600) \to \rho(770) \pi$ amplitude, which interferes with a nonresonant $1^{-+}$ amplitude. We demonstrate that conflicting conclusions from previous studies on these amplitudes can be attributed to different analysis models and different treatment of the dependence of the amplitudes on the squared four-momentum transfer and we thus reconcile their experimental findings. We study the nonresonant contributions to the $\pi^-\pi^-\pi^+$ final state using pseudo-data generated on the basis of a Deck model. Subjecting pseudo-data and real data to the same partial-wave analysis, we find good agreement concerning the spectral shape and its dependence on the squared four-momentum transfer for the $J^{PC} = 1^{-+}$ amplitude and also for amplitudes with other $J^{PC}$ quantum numbers. We investigate for the first time the amplitude of the $\pi^-\pi^+$ subsystem with $J^{PC} = 1^{--}$ in the $3\pi$ amplitude with $J^{PC} = 1^{-+}$ employing the novel freed-isobar analysis scheme. We reveal this $\pi^-\pi^+$ amplitude to be dominated by the $\rho(770)$ for both the $\pi_1(1600)$ and the nonresonant contribution. We determine the $\rho(770)$ resonance parameters within the three-pion final state. These findings largely confirm the underlying assumptions for the isobar model used in all previous partial-wave analyses addressing the $J^{PC} = 1^{-+}$ amplitude.