Transverse-spin-dependent azimuthal asymmetries of pion and kaon pairs produced in muon-proton and muon-deuteron semi-inclusive deep inelastic scattering

Alexeev, G. D.; Alexeev, M. G.; Alice, C.; Amoroso, A.; Andrieux, V.; Anosov, V.; Augsten, K.; Augustyniak, W.; Azevedo, C. D. R.; Badelek, B.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bodlak, M.; Bradamante, F.; Braun, C.; 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.; Dalla Torre, S.; Dasgupta, S. S.; Dasgupta, S.; Del Carro, F.; Denisenko, I.; Denisov, O. Yu.; Donskov, S. V.; Doshita, N.; Dreisbach, Ch.; Dünnweber, W.; Dusaev, R. R.; Ecker, D.; Efremov, A.; Elia, C.; Eremeev, D.; Faccioli, P.; Faessler, M.; Finger, M.; Finger, M.; Fischer, H.; Flöthner, K. J.; Florian, W.; Friedrich, J. M.; Frolov, V.; Garcia Ordòñez, L. G.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Giarra, J.; Giordano, D.; Gorzellik, M.; Grasso, A.; Gridin, A.; Grosse Perdekamp, M.; Grube, B.; Grüner, M.; Guskov, A.; von Harrach, D.; Hoffmann, M.; Horikawa, N.; D'Hose, N.; Hsieh, C. -Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Iwata, T.; Jandek, M.; Jary, V.; Joosten, R.; Kabuß, E.; Kaspar, F.; Kerbizi, A.; Ketzer, B.; Khatun, A.; Khaustov, G. V.; Klein, F.; Koivuniemi, J. H.; Kolosov, V. N.; Kondo Horikawa, K.; Konorov, I.; Konstantinov, V. F.; Korzenev, A. M.; Kotzinian, A. M.; Kouznetsov, O. M.; Koval, A.; Kral, Z.; Krinner, F.; 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.; Martin, A.; Marzec, J.; Matoušek, J.; Matsuda, T.; Mattson, G.; Menezes Pires, C.; Metzger, F.; Meyer, M.; Meyer, W.; Mikhailov, Yu. V.; Mikhasenko, M.; Mitrofanov, E.; Miura, D.; Miyachi, Y.; Molina, R.; Moretti, A.; Nagaytsev, A.; Neyret, D.; Niemiec, M.; Nový, J.; Nowak, W. -D.; Nukazuka, G.; Olshevsky, A. G.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pekeler, H.; Peng, J. -C.; Pesaro, G.; Pešek, M.; Peshekhonov, D. V.; Pešková, M.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Quaresma, M.; Quintans, C.; Reicherz, G.; Riedl, C.; Ryabchikov, D. I.; Rychter, A.; Rymbekova, A.; Samoylenko, V. D.; Sandacz, A.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schmieden, H.; Selyunin, A.; Sharko, K.; Sinha, L.; Slunecka, M.; Sozzi, F.; Spülbeck, D.; Srnka, A.; Stolarski, M.; Subrt, O.; Sulc, M.; Suzuki, H.; Tessaro, S.; Tessarotto, F.; Thiel, A.; Tomsa, J.; Tosello, F.; Townsend, A.; Triloki, T.; Tskhay, V.; Valinoti, B.; Veit, B. M.; Veloso, J. F. C. A.; Ventura, B.; Virius, M.; Wagner, M.; Wallner, S.; Zaremba, K.; Zavertyaev, M.; Zemko, M.; Zemlyanichkina, E.; Ziembicki, M.

doi:10.1016/j.physletb.2023.138155

A set of measurements of azimuthal asymmetries in the production of pairs of identified hadrons in deep-inelastic scattering of muons on transversely polarised (LiD)-Li-6 (deuteron) and NH3 (proton) targets is presented. All available data collected in the years 2003-2004 and 2007/2010 with the COMPASS spectrometer using a muon beam of 160GeV/c at the CERN SPS were analysed. The asymmetries provide access to the transversity distribution functions via a fragmentation function that in principle may be independently obtained from e(+)e(-) annihilation data. Results are presented, discussed and compared to existing measurements as well as to model predictions. Asymmetries of pi(+)pi(-) pairs measured with the proton target as a function of the Bjorken scaling variable are sizeable in the range x>0.032, indicating non-vanishing transversity distribution and di-hadron interference fragmentation functions. As already pointed out by several authors, the small asymmetries of pi(+)pi(-) measured on the (LiD)-Li-6 target can be interpreted as indication for a cancellation of u and d-quark transversity distributions.(c) 2023 Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).