RT Journal Article
T1 Angular analysis of B0→D∗−D∗+s with D∗+s→D+sγ decays
A1 LHCb Collaboration, 
A1 Adeva Andany, Bernardo
A1 Baladrón Rodríguez, Pablo
A1 Boente García, Óscar
A1 Brea Rodríguez, Alexandre
A1 Casais Vidal, Adrián
A1 Chobanova, Veronika
A1 Cid Vidal, Xabier
A1 Dalseno, Jeremy
A1 Dieste Maroñas, Lorena
A1 Fernández Prieto, Antonio
A1 Gallas Torreira, Abraham Antonio
A1 García Plana, Beatriz
A1 Gioventù, Alessandra
A1 Lomba Castro, Julián
A1 Martínez Santos, Diego
A1 Parkinson, Chris J.
A1 Plo Casasus, Máximo
A1 Prouve, Claire
A1 Romero Lamas, Marcos
A1 Romero Vidal, Antonio
A1 Saborido Silva, Juan José
A1 Santamarina Ríos, Cibrán
A1 Sellam, Sara
A1 Vázquez Gómez, R.
A1 Vázquez Regueiro, Pablo
K1 B physics
K1 Branching fraction
K1 Hadron-Hadron scattering (experiments)
K1 Polarization
AB The first full angular analysis of the B0→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→D+sγ and D*− → D¯¯¯¯0π− vector meson decays are used with the subsequent D+s → K+K−π+ and D¯¯¯¯0 → K+π− decays. All helicity amplitudes and phases are measured, and the longitudinal polarisation fraction is determined to be fL = 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(B0→D∗−D∗+s) × ℬ(D∗+s→D+sγ)]/ℬ(B0 → D*−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 Bs → D*−D+s decay is made with a significance of seven standard deviations. The branching fraction ratio ℬ(Bs → D*−D+s)/ℬ(B0 → D*−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
PB Springer
YR 2021
FD 2021
LK http://hdl.handle.net/10347/26693
UL http://hdl.handle.net/10347/26693
LA eng
NO The LHCb collaboration., Aaij, R., Abellán Beteta, C. et al. Angular analysis of B0→D∗−D∗+s with D∗+s→D+sγ decays. J. High Energ. Phys. 2021, 177 (2021). https://doi.org/10.1007/JHEP06(2021)177
DS Minerva
RD 29 abr 2026