Angular analysis of $$ {B}^0\to {D}^{\ast -}{D}_s^{\ast +} $$ with $$ {D}_s^{\ast +}\to {D}_s^{+}\gamma $$ decays

Aaij, R; Abellán Beteta, C; Ackernley, T; Adeva, B; Adinolfi, M; Afsharnia, H; Aidala, CA; Aiola, S; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Alfonso Albero, A; Aliouche, Z; Alkhazov, G; Alvarez Cartelle, P; Amato, S; Amhis, Y; An, L; Anderlini, L; Andreianov, A; Andreotti, M; Archilli, F; Artamonov, A; John, M; Malde, S; Pajero, T

Journal article

Angular analysis of $$ {B}^0\to {D}^{\ast -}{D}_s^{\ast +} $$ with $$ {D}_s^{\ast +}\to {D}_s^{+}\gamma $$ decays

Abstract:: A bstract The first full angular analysis of the $$ {B}^0\to {D}^{\ast -}{D}_s^{\ast +} $$ B 0 → D ∗ − D s ∗ + decay is performed using 6 fb − 1 of pp collision data collected with the LHCb experiment at a centre-of-mass energy of 13 TeV. The $$ {D}_s^{\ast +}\to {D}_s^{+}\gamma $$ D s ∗ + → D s + γ and D * − → $$ {\overline{D}}^0{\pi}^{-} $$ D ¯ 0 π − vector meson decays are used with the subsequent $$ {D}_s^{+} $$ D s + → K + K − π + and $$ {\overline{D}}^0 $$ D ¯ 0 → K + π − decays. All helicity amplitudes and phases are measured, and the longitudinal polarisation fraction is determined to be f L = 0 . 578 ± 0 . 010 ± 0 . 011 with world-best precision, where the first uncertainty is statistical and the second is systematic. The pattern of helicity amplitude magnitudes is found to align with expectations from quark-helicity conservation in B decays. The ratio of branching fractions [ℬ( $$ {B}^0\to {D}^{\ast -}{D}_s^{\ast +} $$ B 0 → D ∗ − D s ∗ + ) × ℬ( $$ {D}_s^{\ast +}\to {D}_s^{+}\gamma $$ D s ∗ + → D s + γ )] / ℬ( B 0 → D * − $$ {D}_s^{+} $$ D s + ) is measured to be 2 . 045 ± 0 . 022 ± 0 . 071 with world-best precision. In addition, the first observation of the Cabibbo-suppressed B s → D * − $$ {D}_s^{+} $$ D s + decay is made with a significance of seven standard deviations. The branching fraction ratio ℬ( B s → D * − $$ {D}_s^{+} $$ D s + ) / ℬ( B 0 → D * − $$ {D}_s^{+} $$ D s + ) is measured to be 0 . 049 ± 0 . 006 ± 0 . 003 ± 0 . 002, where the third uncertainty is due to limited knowledge of the ratio of fragmentation fractions.

Publication status:: Published

Peer review status:: Peer reviewed

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APA Style

Aaij, R., Abellán Beteta, C., Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., Aidala, C. A., Aiola, S., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Alfonso Albero, A., Aliouche, Z., Alkhazov, G., Alvarez Cartelle, P., Amato, S., Amhis, Y., … Pajero, T. (2021). Angular analysis of $$ {B}^0\to {D}^{\ast -}{D}_s^{\ast +} $$ with $$ {D}_s^{\ast +}\to {D}_s^{+}\gamma $$ decays. Journal of High Energy Physics, 2021(6), 177.

MLA Style

Aaij, R, et al. “Angular Analysis of $$ {B}^0\to {D}^{\Ast -}{D}_s^{\Ast +} $$ with $$ {D}_s^{\Ast +}\to {D}_s^{+}\Gamma $$ Decays.” Journal of High Energy Physics, vol. 2021, no. 6, 2021, p. 177.

Chicago Style

Aaij, R, C Abellán Beteta, T Ackernley, et al. 2021. “Angular Analysis of $$ {B}^0\to {D}^{\Ast -}{D}_s^{\Ast +} $$ with $$ {D}_s^{\Ast +}\to {D}_s^{+}\Gamma $$ Decays.” Journal of High Energy Physics 2021 (6): 177.
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