Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userObservation of the decay $Xi_b^- to p K^-K^-$
80
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Decays of the $Xi_b^-$ and $Omega_b^-$ baryons to the charmless final states $p h^{-}h^{prime -}$, where $h^{(prime)}$ denotes a kaon or pion, are searched for with the LHCb detector. The analysis is based on a sample of proton-proton collision data collected at centre-of-mass energies $sqrt{s} = 7$ and $8 TeV$, corresponding to an integrated luminosity of $3 {rm fb}^{-1}$. The decay $Xi_b^- to p K^-K^-$ is observed with a significance of $8.7$ standard deviations, and evidence at the level of $3.4$ standard deviations is found for the $Xi_b^- to p K^-pi^-$ decay. Results are reported, relative to the $B^-to K^+K^-K^-$ normalisation channel, for the products of branching fractions and $b$-hadron production fractions. The branching fractions of $Xi_b^- to p K^-pi^-$ and $Xi_b^- to p pi^-pi^-$ relative to $Xi_b^- to p K^-K^-$ decays are also measured.
rate research
Read More
The decay $Lambda_b^0 to eta_c(1S) p K^-$ is observed for the first time using a data sample of proton-proton collisions, corresponding to an integrated luminosity of 5.5 $fb^{-1}$, collected with the LHCb experiment at a center-of-mass energy of 13 TeV. The branching fraction of the decay is measured, using the $Lambda_b^0 to J/psi p K^-$ decay as a normalization mode, to be $mathcal{B}(Lambda_b^0 to eta_c(1S) p K^-)=(1.06pm0.16pm0.06^{+0.22}_{-0.19})times10^{-4}$, where the quoted uncertainties are statistical, systematic and due to external inputs, respectively. A study of the $eta_c(1S) p$ mass spectrum is performed to search for the $P_c(4312)^+$ pentaquark state. No evidence is observed and an upper limit of begin{equation*} frac{mathcal{B}(Lambda_b^0 to P_c(4312)^+ K^-)times mathcal{B}(P_c(4312)^+ to eta_c(1S) p)}{mathcal{B}(Lambda_b^0 to eta_c(1S) p K^-)} < 0.24 end{equation*} is obtained at the 95% confidence level.
A search for the $B^{0}to K^{+}K^{-}$ decay is performed using $pp$-collision data collected by LHCb. The data set corresponds to integrated luminosities of 1 and 2 fb$^{-1}$ at center-of-mass energies of 7 and 8 TeV, respectively. This decay is observed for the first time, with a significance of more than five standard deviations. The analysis also results in an improved measurement of the branching fraction for the $B_s^0to pi^+pi^-$ decay. The measured branching fractions are $BR(B^0to K^+K^-) = (7.80 pm 1.27 pm 0.81 pm 0.21) times 10^{-8}$ and $BR(B_s^0topi^+pi^-) = (6.91 pm 0.54 pm 0.63 pm 0.19 pm 0.40) times 10^{-7}$. The first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the $B^0to K^+pi^-$ branching fraction used as a normalization. For the $B_s^0$ mode, the fourth accounts for the uncertainty on the ratio of the probabilities for $b$ quarks to hadronize into $B_s^0$ and $B^0$ mesons.
The first observation of the $B_s^0 to overline{D}^0 K^+ K^-$ decay is reported, together with the most precise branching fraction measurement of the mode $B^0 to overline{D}^0 K^+ K^-$. The results are obtained from an analysis of $pp$ collision data corresponding to an integrated luminosity of $3.0~textrm{fb}^{-1}$. The data were collected with the LHCb detector at centre-of-mass energies of $7$ and $8$ TeV. The branching fraction of the $B^0 to overline{D}^0 K^+ K^-$ decay is measured relative to that of the decay $B^0 to overline{D}^0 pi^+ pi^-$ to be $$frac{mathcal{B}(B^0 to overline{D}^0 K^+ K^-)}{mathcal{B}(B^0 to overline{D}^0 pi^+ pi^-)} = (6.9 pm 0.4 pm 0.3)%,$$ where the first uncertainty is statistical and the second is systematic. The measured branching fraction of the $B_s^0 to overline{D}^0 K^+ K^-$ decay mode relative to that of the corresponding $B^0$ decay is $$frac{mathcal{B}(B_s^0 to overline{D}^0 K^+ K^-)}{mathcal{B}(B^0 to overline{D}^0 K^+ K^-)} = (93.0 pm 8.9 pm 6.9)%.$$ Using the known branching fraction of ${B^0 to overline{D}^0 pi^+ pi^-}$, the values of ${{mathcal B}(B^0 to overline{D}^0 K^+ K^- )=(6.1 pm 0.4 pm 0.3 pm 0.3) times 10^{-5}}$, and ${{cal B}(B_s^0 to overline{D}^0 K^+ K^-)=}$ $(5.7 pm 0.5 pm 0.4 pm 0.5) times 10^{-5}$ are obtained, where the third uncertainties arise from the branching fraction of the decay modes ${B^0 to overline{D}^0 pi^+ pi^-}$ and $B^0 to overline{D}^0 K^+ K^-$, respectively.
The $varLambda^0_b to varLambda^+_c K^+ K^- pi^-$ decay is observed for the first time using a data sample of proton-proton collisions at centre-of-mass energies of $sqrt{s}=7$ and 8 $rm{TeV}$ collected by the $mbox{LHCb}$ detector, corresponding to an integrated luminosity of $3{rm{fb}^{-1}}$. The ratio of branching fractions between the $varLambda^0_b to varLambda^+_c K^+ K^- pi^-$ and the $varLambda^{0}_{b}tovarLambda^{+}_{c}D^{-}_{s}$ decays is measured to be begin{equation*} frac{mathcal{B} ( varLambda^0_b to varLambda^+_c K^+ K^- pi^-) } {mathcal{B} ( varLambda^0_b to varLambda^+_c D^-_s)} = (9.26 pm 0.29 pm 0.46 pm 0.26)times10^{-2}, end{equation*} where the first uncertainty is statistical, the second systematic and the third is due to the knowledge of the $D^-_s to K^+ K^- pi^-$ branching fraction. No structure on the invariant mass distribution of the $varLambda^+_c K^+$ system is found, consistent with no open-charm pentaquark signature.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
