First measurement of the CP-violating phase in B0s→J/ψ( → e+e−)ϕ decays

A flavour-tagged time-dependent angular analysis of B0 s → J/ψφ decays is presented where the J/ψ meson is reconstructed through its decay to an e +e − pair. The analysis uses a sample of pp collision data recorded with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb−1 . The CP-violating phase and lifetime parameters of the B0 s system are measured to be φs = 0.00 ± 0.28 ± 0.05 rad, ∆Γs = 0.115 ± 0.045 ± 0.011 ps−1 and Γs = 0.608 ± 0.018 ± 0.011 ps−1 where the first uncertainty is statistical and the second systematic. This is the first time that CP-violating parameters are measured in the B0 s → J/ψφ decay with an e +e − pair in the final state. The results are consistent with previous measurements in other channels and with the Standard Model predictions

Search for the doubly heavy Ξbc0 baryon via decays to D 0 pK −

A search for the doubly heavy Ξ0bc baryon using its decay to the D0pK- final state is performed using proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the LHCb experiment between 2016 and 2018, corresponding to an integrated luminosity of 5.4 fb−1. No significant signal is found in the invariant mass range from 6.7 to 7.2 GeV/c2. Upper limits are set at 95% credibility level on the ratio of the Ξ0bc production cross-section times its branching fraction to D0pK− relative to that of the Λ0b→D0pK− decay. The limits are set as a function of the Ξ0bc mass and lifetime hypotheses, in the rapidity range from 2.0 to 4.5 and in the transverse momentum region from 5 to 25 GeV/c. Upper limits range from 1.7 × 10−2 to 3.0 × 10−1 for the considered Ξ0bc mass and lifetime hypotheses

Measurement of the CKM angle γγ in B±→DK±B^\pm\to D K^\pm and B±→Dπ±B^\pm \to D π^\pm decays with D→KS0h+h−D \to K_\mathrm S^0 h^+ h^-

A measurement of $CP$-violating observables is performed using the decays $B^\pm\to D K^\pm$ and $B^\pm\to D \pi^\pm$, where the $D$ meson is reconstructed in one of the self-conjugate three-body final states $K_{\mathrm S}\pi^+\pi^-$ and $K_{\mathrm S}K^+K^-$ (commonly denoted $K_{\mathrm S} h^+h^-$). The decays are analysed in bins of the $D$-decay phase space, leading to a measurement that is independent of the modelling of the $D$-decay amplitude. The observables are interpreted in terms of the CKM angle $\gamma$. Using a data sample corresponding to an integrated luminosity of $9\,\text{fb}^{-1}$ collected in proton-proton collisions at centre-of-mass energies of $7$, $8$, and $13\,\text{TeV}$ with the LHCb experiment, $\gamma$ is measured to be $\left(68.7^{+5.2}_{-5.1}\right)^\circ$. The hadronic parameters $r_B^{DK}$, $r_B^{D\pi}$, $\delta_B^{DK}$, and $\delta_B^{D\pi}$, which are the ratios and strong-phase differences of the suppressed and favoured $B^\pm$ decays, are also reported

Measurement of the branching fraction of the B0→Ds+π−{{B} ^0} {\rightarrow }{{D} ^+_{s}} {{\pi } ^-} decay

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

Search for the rare decay B 0 → J / ψϕ * * Individual groups or members have received support from AvH Foundation (Germany); EPLANET, Marie Sk lodowska-Curie Actions and ERC (European Union); A*MIDEX, ANR, Labex P2IO and OCEVU, and R´egion Auvergne-Rhˆone-Alpes (France); Key Research Program of Frontier Sciences of CAS, CAS PIFI, Thousand Talents Program, and Sci. & Tech. Program of Guangzhou (China); RFBR, RSF and Yandex LLC (Russia); GVA, XuntaGal and GENCAT (Spain); the Royal Society and the Leverhulme Trust (United Kingdom)

Abstract: A search for the rare decay is performed using collision data collected with the LHCb dete-ctor at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb−1. No significant signal of the decay is observed and an upper limit of at 90% confidence level is set on the branching fraction

Search for the rare decay B 0 → J / ψϕ * * Individual groups or members have received support from AvH Foundation (Germany); EPLANET, Marie Sk lodowska-Curie Actions and ERC (European Union); A*MIDEX, ANR, Labex P2IO and OCEVU, and R´egion Auvergne-Rhˆone-Alpes (France); Key Research Program of Frontier Sciences of CAS, CAS PIFI, Thousand Talents Program, and Sci. & Tech. Program of Guangzhou (China); RFBR, RSF and Yandex LLC (Russia); GVA, XuntaGal and GENCAT (Spain); the Royal Society and the Leverhulme Trust (United Kingdom)

Abstract: A search for the rare decay is performed using collision data collected with the LHCb dete-ctor at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb−1. No significant signal of the decay is observed and an upper limit of at 90% confidence level is set on the branching fraction

Search for the rare decay B 0 → J / ψϕ * * Individual groups or members have received support from AvH Foundation (Germany); EPLANET, Marie Sk lodowska-Curie Actions and ERC (European Union); A*MIDEX, ANR, Labex P2IO and OCEVU, and Région Auvergne-Rhône-Alpes (France); Key Research Program of Frontier Sciences of CAS, CAS PIFI, Thousand Talents Program, and Sci. & Tech. Program of Guangzhou (China); RFBR, RSF and Yandex LLC (Russia); GVA, XuntaGal and GENCAT (Spain); the Royal Society and the Leverhulme Trust (United Kingdom)

Abstract: A search for the rare decay is performed using collision data collected with the LHCb dete-ctor at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb−1. No significant signal of the decay is observed and an upper limit of at 90% confidence level is set on the branching fraction

Measurement of the branching fraction of the B0→Ds+π−{{B} ^0} {\rightarrow }{{D} ^+_{s}} {{\pi } ^-} decay

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

Search for the rare decay B 0 → J / ψϕ * * Individual groups or members have received support from AvH Foundation (Germany); EPLANET, Marie Sk lodowska-Curie Actions and ERC (European Union); A*MIDEX, ANR, Labex P2IO and OCEVU, and Région Auvergne-Rhône-Alpes (France); Key Research Program of Frontier Sciences of CAS, CAS PIFI, Thousand Talents Program, and Sci. & Tech. Program of Guangzhou (China); RFBR, RSF and Yandex LLC (Russia); GVA, XuntaGal and GENCAT (Spain); the Royal Society and the Leverhulme Trust (United Kingdom)

Abstract: A search for the rare decay is performed using collision data collected with the LHCb dete-ctor at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb−1. No significant signal of the decay is observed and an upper limit of at 90% confidence level is set on the branching fraction

Search for the rare decay B 0 → J / ψϕ * * Individual groups or members have received support from AvH Foundation (Germany); EPLANET, Marie Sk lodowska-Curie Actions and ERC (European Union); A*MIDEX, ANR, Labex P2IO and OCEVU, and R´egion Auvergne-Rhˆone-Alpes (France); Key Research Program of Frontier Sciences of CAS, CAS PIFI, Thousand Talents Program, and Sci. & Tech. Program of Guangzhou (China); RFBR, RSF and Yandex LLC (Russia); GVA, XuntaGal and GENCAT (Spain); the Royal Society and the Leverhulme Trust (United Kingdom)

Abstract: A search for the rare decay is performed using collision data collected with the LHCb dete-ctor at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb−1. No significant signal of the decay is observed and an upper limit of at 90% confidence level is set on the branching fraction