1. Azimuthal asymmetries of back-to-back $\pi^\pm-(\pi^0,\eta,\pi^\pm)$ pairs in $e^+e^-$ annihilation
- Author
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Li, H., Vossen, A., Bhardwaj, V., Schwanda, C., Seidl, R., Seino, Y., Senyo, K., Shiu, J.-G., Simon, F., Solovieva, E., Starič, M., Stottler, Z. S., Takizawa, M., Bilka, T., Tanida, K., Tenchini, F., Uchida, M., Uno, S., Van Tonder, R., Varner, G., Wang, B., Wang, C. H., Wang, M.-Z., Wang, P., Biswal, J., Watanabe, M., Won, E., Yang, S. B., Ye, Hua, Zhang, Z. P., Zhilich, V., Zhukova, V., Zhulanov, V., Belle Collaboration, Bobrov, A., Bračko, M., Campajola, M., Cao, L., Červenkov, D., Chekelian, V., Chen, A., Aihara, H., Cheon, B. G., Cho, H. E., Cho, K., Choi, Y., Choudhury, S., Cinabro, D., Cunliffe, S., Di Capua, F., Di Carlo, S., Dong, T. V., Asner, D. M., Eidelman, S., Ferber, T., Fulsom, B. G., Gaur, V., Garmash, A., Giri, A., Goldenzweig, P., Hartbrich, O., Hayasaka, K., Hayashii, H., Aulchenko, V., Huang, K., Inami, K., Ishikawa, A., Itoh, R., Jacobs, W. W., Jang, E.-J., Jia, S., Jin, Y., Kang, K. H., Karyan, G., Aushev, T., Kim, D. Y., Kim, S. H., Kodyš, P., Korpar, S., Kotchetkov, D., Križan, P., Kroeger, R., Krokovny, P., Kwon, Y.-J., Lee, S. C., Babu, V., Li, Y. B., Li Gioi, L., Libby, J., Lieret, K., Liventsev, D., Luo, T., MacQueen, C., Masuda, M., Matsuda, T., Merola, M., Badhrees, I., Miyata, H., Mizuk, R., Mussa, R., Nakano, T., Nakao, M., Nath, K. J., Natkaniec, Z., Nishida, S., Ono, H., Ostrowicz, W., Bakich, A. M., Pakhlov, P., Pakhlova, G., Pal, B., Pardi, S., Patra, S., Paul, S., Pedlar, T. K., Pestotnik, R., Piilonen, L. E., Popov, V., Bennett, J., Prencipe, E., Prim, M. T., Russo, G., Sahoo, D., Santelj, L., Sanuki, T., Savinov, V., Schneider, O., Schnell, G., Schueler, J., Laboratoire de l'Accélérateur Linéaire (LAL), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Belle, and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)
- Subjects
angular distribution: asymmetry ,eta: electroproduction ,13.66.-a ,BELLE ,annihilation [electron positron] ,electron positron: annihilation ,transverse momentum ,transverse momentum dependence ,meson ,10.58 GeV-cms ,fragmentation function ,High Energy Physics - Experiment ,KEK-B ,13.88.+e ,[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex] ,Particle Physics Experiments ,ddc:530 ,thrust ,asymmetry: Collins ,structure ,Collins ,Nuclear Experiment ,Collins [effect] ,14.20.-c ,flavor ,electron positron: colliding beams ,14.65.-q ,annihilation ,asymmetry [angular distribution] ,Collins [asymmetry] ,pair production [pi] ,colliding beams [electron positron] ,High Energy Physics::Experiment ,hadron ,effect: Collins ,pi: pair production ,electroproduction [eta] ,experimental results - Abstract
This work reports the first observation of azimuthal asymmetries around the thrust axis in $e^+e^-$ annihilation of pairs of back-to-back charged pions in one hemisphere, and $\pi^0$ and $\eta$ mesons in the opposite hemisphere. These results are complemented by a new analysis of pairs of back-to-back charged pions. The $\pi^0$ and $\eta$ asymmetries rise with the relative momentum $z$ of the detected hadrons as well as with the transverse momentum with respect to the thrust axis. These asymmetries are sensitive to the Collins fragmentation function $H_1^{\perp}$ and provide complementary information to previous measurements with charged pions and kaons in the final state. In particular, the $\eta$ final states will provide additional information on the flavor structure of $H_1^{\perp}$. This is the first measurement of the explicit transverse-momentum dependence of the Collins fragmentation function from Belle data. It uses a dataset of 980.4~fb$^{-1}$ collected by the Belle experiment at or near a center-of-mass energy of 10.58 GeV., Comment: 31 pages, 14 figures, submitted to PRD
- Published
- 2019
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