Search for elements 119 and 120

Khuyagbaatar, J.; Yakushev, A.; Düllmann, Ch. E.; Ackermann, D.; Andersson, L.-L.; Asai, M.; Block, M.; Boll, R. A.; Brand, H.; Cox, D. M.; Dasgupta, M.; Derkx, X.; Di Nitto, A.; Eberhardt, K.; Even, J.; Evers, M.; Fahlander, C.; Forsberg, U.; Gates, J. M.; Gharibyan, N.; Golubev, P.; Gregorich, K. E.; Hamilton, J. H.; Hartmann, W.; Herzberg, R.-D.; Heßberger, F. P.; Hinde, D. J.; Hoffmann, J.; Hollinger, R.; Hübner, A.; Jäger, E.; Kindler, B.; Kratz, J. V.; Krier, J.; Kurz, N.; Laatiaoui, M.; Lahiri, S.; Lang, R.; Lommel, B.; Maiti, M.; Miernik, K.; Minami, S.; Mistry, A. K.; Mokry, C.; Nitsche, H.; Omtvedt, J. P.; Pang, G. K.; Papadakis, P.; Renisch, D.; Roberto, J. B.; Rudolph, D.; Runke, J.; Rykaczewski, K. P.; Sarmiento, L. G.; Schädel, M.; Schausten, B.; Semchenkov, A.; Shaughnessy, D. A.; Steinegger, P.; Steiner, J.; Tereshatov, E. E.; Thörle-Pospiech, P.; Tinschert, K.; Torres De Heidenreich, T.; Trautmann, N.; Türler, A.; Uusitalo, J.; Wegrzecki, M.; Wiehl, N.; Van Cleve, S. M.; Yakusheva, V.

doi:10.1103/physrevc.102.064602

DOE OSTI · 1806438

Search for elements 119 and 120

Khuyagbaatar, J.·Yakushev, A.·Düllmann, Ch. E.·Ackermann, D.·Andersson, L.-L.·Asai, M.·Block, M.·Boll, R. A.·Brand, H.·Cox, D. M.·Dasgupta, M.·Derkx, X.·Di Nitto, A.·Eberhardt, K.·Even, J.·Evers, M.·Fahlander, C.·Forsberg, U.·Gates, J. M.·Gharibyan, N.·Golubev, P.·Gregorich, K. E.·Hamilton, J. H.·Hartmann, W.·Herzberg, R.-D.·Heßberger, F. P.·Hinde, D. J.·Hoffmann, J.·Hollinger, R.·Hübner, A.·Jäger, E.·Kindler, B.·Kratz, J. V.·Krier, J.·Kurz, N.·Laatiaoui, M.·Lahiri, S.·Lang, R.·Lommel, B.·Maiti, M.·Miernik, K.·Minami, S.·Mistry, A. K.·Mokry, C.·Nitsche, H.·Omtvedt, J. P.·Pang, G. K.·Papadakis, P.·Renisch, D.·Roberto, J. B.·Rudolph, D.·Runke, J.·Rykaczewski, K. P.·Sarmiento, L. G.·Schädel, M.·Schausten, B.·Semchenkov, A.·Shaughnessy, D. A.·Steinegger, P.·Steiner, J.·Tereshatov, E. E.·Thörle-Pospiech, P.·Tinschert, K.·Torres De Heidenreich, T.·Trautmann, N.·Türler, A.·Uusitalo, J.·Wegrzecki, M.·Wiehl, N.·Van Cleve, S. M.·Yakusheva, V.

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Abstract

In this work, a search for production of the superheavy elements with atomic numbers 119 and 120 was performed in the 50 Ti + 249 Bk and 50 Ti + 249 Cf fusion-evaporation reactions, respectively, at the gas-filled recoil separator TASCA at GSI Darmstadt, Germany. Over four months of irradiation, the 249 Bk target partially decayed into 249 Cf, which allowed for a simultaneous search for both elements. Neither was detected at cross-section sensitivity levels of 65 and 200 fb for the 50 Ti + 249 Bk and 50 Ti + 249 Cf reactions, respectively, at a midtarget beam energy of E lab = 281.5 MeV. The nonobservation of elements 119 and 120 is discussed within the concept of fusion-evaporation reactions including various theoretical predictions on the fission-barrier heights of superheavy nuclei in the region of the island of stability.

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Khuyagbaatar, J., Yakushev, A., Düllmann, Ch. E., Ackermann, D., Andersson, L.-L., Asai, M., Block, M., Boll, R. A., Brand, H., Cox, D. M., Dasgupta, M., Derkx, X., Di Nitto, A., Eberhardt, K., Even, J., Evers, M., Fahlander, C., Forsberg, U., Gates, J. M., Gharibyan, N., Golubev, P., Gregorich, K. E., Hamilton, J. H., Hartmann, W., Herzberg, R.-D., Heßberger, F. P., Hinde, D. J., Hoffmann, J., Hollinger, R., Hübner, A., Jäger, E., Kindler, B., Kratz, J. V., Krier, J., Kurz, N., Laatiaoui, M., Lahiri, S., Lang, R., Lommel, B., Maiti, M., Miernik, K., Minami, S., Mistry, A. K., Mokry, C., Nitsche, H., Omtvedt, J. P., Pang, G. K., Papadakis, P., Renisch, D., Roberto, J. B., Rudolph, D., Runke, J., Rykaczewski, K. P., Sarmiento, L. G., Schädel, M., Schausten, B., Semchenkov, A., Shaughnessy, D. A., Steinegger, P., Steiner, J., Tereshatov, E. E., Thörle-Pospiech, P., Tinschert, K., Torres De Heidenreich, T., Trautmann, N., Türler, A., Uusitalo, J., Wegrzecki, M., Wiehl, N., Van Cleve, S. M., Yakusheva, V.. 2020-12-02. Search for elements 119 and 120. https://doi.org/10.1103/physrevc.102.064602

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