Abstract The B¯s0→χc2K+K− $$ {\overline{B}}_s^0\to {\chi}_{c2}{K}^{+}{K}^{-} $$ decay mode is observed and its branching fraction relative to the corresponding χ c1 decay mode, in a ±15 MeV/c 2 ...window around the ϕ mass, is found to be ℬB¯s0→χc2K+K−ℬB¯s0→χc1K+K−=17.1±3.1±0.4±0.9%, $$ \frac{\mathrm{\mathcal{B}}\left({\overline{B}}_s^0\to {\chi}_{c2}{K}^{+}{K}^{-}\right)}{\mathrm{\mathcal{B}}\left({\overline{B}}_s^0\to {\chi}_{c1}{K}^{+}{K}^{-}\right)}=\left(17.1 \pm 3.1\pm 0.4\pm 0.9\right)\%, $$ where the first uncertainty is statistical, the second systematic and the third due to the knowledge of the branching fractions of radiative χ c decays. The decay mode B¯s0→χc1K+K− $$ {\overline{B}}_s^0\to {\chi}_{c1}{K}^{+}{K}^{-} $$ allows the B s 0 mass to be measured as mBs0=5366.83±0.25±0.27MeV/c2, $$ m\left({B}_s^0\right)=5366.83\pm 0.25\pm 0.27\ \mathrm{M}\mathrm{e}\mathrm{V}/{c}^2, $$ where the first uncertainty is statistical and the second systematic. A combination of this result with other LHCb determinations of the B s 0 mass is made.
Abstract A flavour-tagged decay-time-dependent amplitude analysis of B s 0 → (K + π −)(K − π +) decays is presented in the K ± π ∓ mass range from 750 to 1600MeV/c 2. The analysis uses pp collision ...data collected with the LHCb detector at centre-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3.0 fb−1. Several quasi-two-body decay modes are considered, corresponding to K ± π ∓ combinations with spin 0, 1 and 2, which are dominated by the K 0 * (800)0 and K 0 * (1430)0, the K *(892)0 and the K 2 * (1430)0 resonances, respectively. The longitudinal polarisation fraction for the B s 0 → K ∗ 892 ° K ¯ ∗ 892 0 $$ {B}_s^0\to {K}^{\ast }(892){}^{\circ}{\overline{K}}^{\ast }{(892)}^0 $$ decay is measured as f L = 0.208 ± 0.032 ± 0.046, where the first uncertainty is statistical and the second is systematic. The first measurement of the mixing-induced CP-violating phase, ϕ s d d ¯ $$ {\phi}_s^{d\overline{d}} $$ , in b → d d ¯ s $$ b\to d\overline{d}s $$ transitions is performed, yielding a value of ϕ s d d ¯ = − 0.10 ± 0.13 stat ± 0.14 $$ {\phi}_s^{d\overline{d}}=-0.10\pm 0.13\left(\mathrm{stat}\right)\pm 0.14 $$ (syst) rad.
Abstract Kinematic correlations for pairs of beauty hadrons, produced in high energy proton-proton collisions, are studied. The data sample used was collected with the LHCb experiment at ...centre-of-mass energies of 7 and 8 TeV and corresponds to an integrated luminosity of 3 fb−1. The measurement is performed using inclusive b → J/ψX decays in the rapidity range 2 < y J/ψ < 4.5. The observed correlations are in good agreement with theoretical predictions.
Abstract A measurement is presented of decay-time-dependent CP violation in the decays B 0 → J/ψ K S0 and B 0 → ψ(2S)K S0, where the J/ψ is reconstructed from two electrons and the ψ(2S) from two ...muons. 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 -violation observables are measured to be CB0→J/ψKS0=0.12±0.07±0.02,SB0→J/ψKS0=0.83±0.08±0.01,CB0→ψ2SKS0=−0.05±0.10±0.01,SB0→ψ2SKS0=0.84±0.10±0.01, $$ \begin{array}{l}C\left({B}^0\to J/\psi \kern0.5em {K}_{\mathrm{S}}^0\right)=0.12\pm 0.07\pm 0.02,\\ {}S\left({B}^0\to J/\psi \kern0.5em {K}_{\mathrm{S}}^0\right)=0.83\pm 0.08\pm 0.01,\\ {}C\left({B}^0\to \psi (2S){K}_{\mathrm{S}}^0\right)=-0.05\pm 0.10\pm 0.01,\\ {}S\left({B}^0\to \psi (2S){K}_{\mathrm{S}}^0\right)=0.84\pm 0.10\pm 0.01,\end{array} $$ where C describes CP violation in the direct decay, and S describes CP violation in the interference between the amplitudes for the direct decay and for the decay after B0−B¯0 $$ {B}^0-{\overline{B}}^0 $$ oscillation. The first uncertainties are statistical and the second are systematic. The two sets of results are compatible with the previous LHCb measurement using B 0 → J/ψ K S0 decays, where the J/ψ meson was reconstructed from two muons. The averages of all three sets of LHCb results are CB0→cc¯KS0=−0.017±0.029,SB0→cc¯KS0=0.760±0.034, $$ \begin{array}{l}C\left({B}^0\to \leftc\overline{c}\right{K}_{\mathrm{S}}^0\right)=-0.017\pm 0.029,\\ {}S\left({B}^0\to \leftc\overline{c}\right{K}_{\mathrm{S}}^0\right)=0.760\pm 0.034,\end{array} $$ under the assumption that higher-order contributions to the decay amplitudes are negligible. The uncertainties include statistical and systematic contributions.
Abstract The charmless three-body decays B ( s)0 → K S0 h + h ′ − (where h (′) = π, K) are analysed using a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated ...luminosity of 3 fb−1. The branching fractions are measured relative to that of the B 0 → K S0 π + π − decay, and are determined to be: ℬB0→KS0K±π∓ℬB0→KS0K+π−=0.123±0.009stat±0.015syst,ℬB0→KS0K+K−ℬB0→KS0π+π−=0.549±0.018stat±0.033syst,ℬBs0→KS0π+π−ℬB0→KS0π+π−=0.191±0.027stat±0.031syst±0.011fs/fd,ℬBs0→KS0K±π∓ℬB0→KS0π+π−=1.70±0.07stat±0.11syst±0.10fs/fd,ℬBs0→KS0K+K−ℬB0→KS0π+π−∈0.008−0.051at90%confidencelevel, $$ \begin{array}{l}\frac{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{K}^{\pm }{\pi}^{\mp}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{K}^{+}{\pi}^{-}\right)}=0.123\pm 0.009\left(\mathrm{stat}\right)\pm 0.015\left(\mathrm{syst}\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{K}^{+}{K}^{-}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}=0.549\pm 0.018\left(\mathrm{stat}\right)\pm 0.033\left(\mathrm{syst}\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}_s^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}=0.191\pm 0.027\left(\mathrm{stat}\right)\pm 0.031\left(\mathrm{syst}\right)\pm 0.011\left({f}_s/{f}_d\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}_s^0\to {K}_{\mathrm{S}}^0{K}^{\pm }{\pi}^{\mp}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}=1.70\pm 0.07\left(\mathrm{stat}\right)\pm 0.11\left(\mathrm{syst}\right)\pm 0.10\left({f}_s/{f}_d\right),\hfill \\ {}\frac{\mathrm{\mathcal{B}}\left({B}_s^0\to {K}_{\mathrm{S}}^0{K}^{+}{K}^{-}\right)}{\mathrm{\mathcal{B}}\left({B}^0\to {K}_{\mathrm{S}}^0{\pi}^{+}{\pi}^{-}\right)}\in \left0.008-0.051\right\kern0.5em \mathrm{at}\kern0.5em 90\%\kern0.5em \mathrm{confidence}\kern0.5em \mathrm{level},\hfill \end{array} $$ where f s /f d represents the ratio of hadronisation fractions of the B s 0 and B 0 mesons.
Abstract Production of prompt D 0 mesons is studied in proton-lead and lead-proton collisions recorded at the LHCb detector at the LHC. The data sample corresponds to an integrated luminosity of ...1.58±0.02 nb−1 recorded at a nucleon-nucleon centre-of-mass energy of s N N = 5 $$ \sqrt{s_{\mathrm{NN}}}=5 $$ TeV. Measurements of the differential cross-section, the forward-backward production ratio and the nuclear modification factor are reported using D 0 candidates with transverse momenta less than 10 GeV/c and rapidities in the ranges 1.5 < y ∗ < 4.0 and −5.0 < y ∗ < −2.5 in the nucleon-nucleon centre-of-mass system.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) A study of B s 0 → η c ϕ and B s 0 → η c π + π − decays is performed using pp collision data corresponding to an ...integrated luminosity of 3.0 fb−1, collected with the LHCb detector in Run 1 of the LHC. The observation of the decay B s 0 → η c ϕ is reported, where the η c meson is reconstructed in the ..., K + K − π + π −, π + π − π + π − and K + K − K + K − decay modes and the ϕ(1020) in the K + K − decay mode. The decay B s 0 → J/ψϕ is used as a normalisation channel. Evidence is also reported for the decay B s 0 → η c π + π −, where the η c meson is reconstructed in the ... decay mode, using the decay B s 0 → J/ψπ + π − as a normalisation channel. The measured branching fractions are ... where in each case the first uncertainty is statistical, the second systematic and the third uncertainty is due to the limited knowledge of the external branching fractions. Figure not available: see fulltext.
Study of the D^sup 0^p amplitude decays Adeva, B; Ajaltouni, Z; Amhis, Y ...
The journal of high energy physics,
05/2017, Letnik:
2017, Številka:
5
Journal Article
Recenzirano
Odprti dostop
An amplitude analysis of the decay Lambda ^sub b ^ ^sup 0^ right arrowD ^sup 0^ ppi ^sup -^ is performed in the part of the phase space containing resonances in the D ^sup 0^ p channel. The study is ...based on a data sample corresponding to an integrated luminosity of 3.0 fb^sup -1^ of pp collisions recorded by the LHCb experiment. The spectrum of excited Lambda ^sub c ^ ^sup +^ states that decay into D ^sup 0^ p is studied. The masses, widths and quantum numbers of the Lambda^sub c^(2880)^sup +^ and Lambda^sub c^(2940)^sup +^ resonances are measured. The constraints on the spin and parity for the Lambda^sub c^(2940)^sup +^ state are obtained for the first time. A near-threshold enhancement in the D ^sup 0^ p amplitude is investigated and found to be consistent with a new resonance, denoted the Lambda^sub c^(2860)^sup +^, of spin 3/2 and positive parity. Figure not available: see fulltext.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract The ratio of branching fractions and the difference in CP asymmetries of the decays B + arrow right J/ + and B + ...arrow right J/psiK + are measured using a data sample of pp collisions collected by the LHCb experiment, corresponding to an integrated luminosity of 3 fb-1 at centre-of-mass energies of 7 and 8 TeV. The results are ... ... where the first uncertainties are statistical and the second are systematic. Combining this result with a recent LHCb measurement of ... provides the most precise estimate to date of CP violation in the decay B + arrow right J/ψπ +, ...Figure not available: see fulltext.
Using proton-proton collision data corresponding to an integrated luminosity of 3.0 fb^{-1}, recorded by the LHCb detector at center-of-mass energies of 7 and 8 TeV, the B_{c}^{+}→D^{0}K^{+} decay ...is observed with a statistical significance of 5.1 standard deviations. By normalizing to B^{+}→Dover ¯^{0}π^{+} decays, a measurement of the branching fraction multiplied by the production rates for B_{c}^{+} relative to B^{+} mesons in the LHCb acceptance is obtained, R_{D^{0}K}=(f_{c}/f_{u})×B(B_{c}^{+}→D^{0}K^{+})=(9.3_{-2.5}^{+2.8}±0.6)×10^{-7}, where the first uncertainty is statistical and the second is systematic. This decay is expected to proceed predominantly through weak annihilation and penguin amplitudes, and is the first B_{c}^{+} decay of this nature to be observed.
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