Measurement of the branching fraction of the $${{B} ^0} {\rightarrow }{{D} ^+_{s}} {{\pi } ^-} $$ decay

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2021-04, Vol.81 (4), Article 314
• Main Authors: Aaij, R., Beteta, C. Abellán, Ackernley, T., Adeva, B., Adinolfi, M., Afsharnia, H., Aidala, C. A., Aiola, S., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Albero, A. Alfonso, Aliouche, Z., Alkhazov, G., Cartelle, P. Alvarez, Amato, S., Amhis, Y., An, L., Anderlini, L., Andreianov, A., Andreotti, M., Archilli, F., Artamonov, A., Artuso, M., Arzymatov, K., Aslanides, E., Atzeni, M., Audurier, B., Bachmann, S., Bachmayer, M., Back, J. J., Baker, S., Rodriguez, P. Baladron, Balagura, V., Baldini, W., Leite, J. Baptista, Barlow, R. J., Barsuk, S., Barter, W., Bartolini, M., Baryshnikov, F., Basels, J. M., Bassi, G., Batsukh, B., Battig, A., Bay, A., Becker, M., Bedeschi, F., Bediaga, I., Beiter, A., Belavin, V., Belin, S., Bellee, V., Belous, K., Belov, I., Belyaev, I., Bencivenni, G., Ben-Haim, E., Berezhnoy, A., Bernet, R., Berninghoff, D., Bernstein, H. C., Bertella, C., Bertolin, A., Betancourt, C., Betti, F., Bezshyiko, Ia, Bhasin, S., Bhom, J., Bian, L., Bieker, M. S., Bifani, S., Billoir, P., Birch, M., Bishop, F. C. R., Bizzeti, A., Bjørn, M., Blago, M. P., Blake, T., Blanc, F., Blusk, S., Bobulska, D., Boelhauve, J. A., Garcia, O. Boente, Boettcher, T., Boldyrev, A., Bondar, A., Bondar, N., Borghi, S., Borisyak, M., Borsato, M., Borsuk, J. T., Bouchiba, S. A., Bowcock, T. J. V., Boyer, A., Bozzi, C., Bradley, M. J., Braun, S.
• Format: Article
• Language: English
• Subjects: ATOMIC AND MOLECULAR PHYSICS; High Energy Physics - Experiment; NUCLEAR PHYSICS AND RADIATION PHYSICS; Physics
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-020-08790-2

A branching fraction measurement of the $${{B} ^0} {\rightarrow }{{D} ^+_{s}} {{\pi } ^-} $$ B 0 → D s + π - decay is presented using proton–proton collision data collected with the LHCb experiment, corresponding to an integrated luminosity of $$5.0\,\text {fb} ^{-1} $$ 5.0 fb - 1 . The branching fraction is found to be $${\mathcal {B}} ({{B} ^0} {\rightarrow }{{D} ^+_{s}} {{\pi } ^-} ) =(19.4 \pm $$ B ( B 0 → D s + π - ) = ( 19.4 ± $$1.8\pm 1.3 \pm 1.2)\times 10^{-6}$$ 1.8 ± 1.3 ± 1.2 ) × 10 - 6 , where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the $${{B} ^0} {\rightarrow }{{D} ^-} {{\pi } ^+} $$ B 0 → D - π + , $${{D} ^+_{s}} {\rightarrow }{{K} ^+} {{K} ^-} {{\pi } ^+} $$ D s + → K + K - π + and $${{D} ^-} {\rightarrow }{{K} ^+} {{\pi } ^-} {{\pi } ^-} $$ D - → K + π - π - branching fractions. This is the most precise single measurement of this quantity to date. As this decay proceeds through a single amplitude involving a $$b{\rightarrow }u$$ b → u charged-current transition, the result provides information on non-factorisable strong interaction effects and the magnitude of the Cabibbo–Kobayashi–Maskawa matrix element $$V_{ub}$$ V ub . Additionally, the collision energy dependence of the hadronisation-fraction ratio $$f_s/f_d$$ f s / f d is measured through $${{\overline{B}} {}^0_{s}} {\rightarrow }{{D} ^+_{s}} {{\pi } ^-} $$ B ¯ s 0 → D s + π - and $${{B} ^0} {\rightarrow }{{D} ^-} {{\pi } ^+} $$ B 0 → D - π + decays.