Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userStudy of the B- --> J/psi K- pi+ pi- Decay and Measurement of the B- --> X(3872) K- Branching Fraction
162
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
We study the decay B- --> J/psi K- pi+ pi- using 117 million BBbar events collected at the Y(4S) resonance with the BaBar detector at the PEP-II e+ e- asymmetric-energy storage ring. We measure the branching fractions Br(B- --> J/psi K- pi+ pi-) = (116 +- 7 (stat.) +- 9(syst.))* 10-5 and Br(B- --> X(3872)K-)* Br (X(3872) --> J/psi pi+ pi-) =(1.28+- 0.41)* 10-5 and find the mass of the X(3872) to be 3873.4 +- 1.4 MeV/c2. We search for the h_c narrow state in the decay B- --> h_c K-, h_c --> J/psi pi+ pi- and for the decay B- --> J/psi D0 pi-, with D0 --> K- pi+. We set the 90% C.L. limits Br(B- --> h_c K-)* Br (h_c --> J/psi pi+ pi-) <3.4 * 10-6 and Br(B- --> J/psi D0 pi-) <5.2 * 10-5.
rate research
Read More
We present measurements of the decays B+ -> X(3872) K+ and B0 -> X(3872) K0 with X(3872) -> Jpsi pi+ pi-. The data sample used, collected with the BABAR detector at the PEP-II e+e- asymmetric-energy storage ring, corresponds to 455 x 10^6 BBbar pairs. Branching fraction measurements of BF(B+ -> X(3872) K+) x BF(X(3872) -> Jpsi pi+ pi-) = (8.4 +/- 1.5 +/- 0.7) x 10^{-6} and BF(B0 -> X(3872) K0) x BF(X(3872) -> Jpsi pi+ pi- = (3.5 +/- 1.9 +/- 0.4) x 10^{-6} are obtained. We set an upper limit on the natural width of the X(3872) of Gamma < 3.3 MeV/c^2 at the 90% confidence level.
Using $pp$ collision data collected by LHCb at center-of-mass energies $sqrt{s}$ = 7 TeV and 8 TeV, corresponding to an integrated luminosity of 3 fb$^{-1}$, the ratio of the branching fraction of the $B_c^+ rightarrow psi(2S)pi^+$ decay relative to that of the $B_c^+ rightarrow J/psipi^+$ decay is measured to be 0.268 $pm$ 0.032 (stat) $pm$ 0.007 (syst) $pm$ 0.006 (BF). The first uncertainty is statistical, the second is systematic, and the third is due to the uncertainties on the branching fractions of the $J/psi rightarrow mu^+mu^-$ and $psi(2S) rightarrow mu^+mu^-$ decays. This measurement is consistent with the previous LHCb result, and the statistical uncertainty is halved.
A search for the decay $B^0_srightarrow J/psi K^{*0}$ with $K^{*0} rightarrow K^-pi^+$ is performed with 0.37 fb$^{-1}$ of $pp$ collisions at $sqrt{s}$ = 7 TeV collected by the LHCb experiment, finding a $Bs to Jpsi K^-pi^+$ peak of $114 pm 11$ signal events. The $K^-pi^+$ mass spectrum of the candidates in the $B^0_s$ peak is dominated by the $K^{*0}$ contribution. Subtracting the non-resonant $K^-pi^+$ component, the branching fraction of BsJpsiKst is $(4.4_{-0.4}^{+0.5} pm 0.8) times 10^{-5}$, where the first uncertainty is statistical and the second systematic. A fit to the angular distribution of the decay products yields the Kst polarization fractions $f_L = 0.50 pm 0.08 pm 0.02$ and $f_{||} = 0.19^{+0.10}_{-0.08} pm 0.02$.
In this work, we study the localized $CP$ violation and the branching fraction of the four-body decay $bar{B}^0rightarrow K^-pi^+pi^-pi^+$ by employing a quasi-two-body QCD factorization approach. Considering the interference of $bar{B}^0rightarrow bar{K}_0^*(700)rho^0(770)rightarrow K^-pi^+pi^-pi^+$ and $bar{B}^0rightarrow bar{K}^*(892)f_0(500)rightarrow K^-pi^+pi^-pi^+$ channels, we predict $mathcal{A_{CP}}(bar{B}^0rightarrow K^-pi^+pi^-pi^+)in[0.15,0.28]$ and $mathcal{B}(bar{B}^0rightarrow K^-pi^+pi^-pi^+)in[1.73,5.10]times10^{-7}$, respectively, which shows that this two channels interference mechanism can induce the localized $CP$ violation to this four-body decay. Meanwhile, within the two quark model framework for the scalar mesons $f_0(500)$ and $bar{K}_0^*(700)$, we calculate the direct CP violations and branching fractions of the $bar{B}^0rightarrow bar{K}_0^*(700)rho^0(770)$ and $bar{B}^0rightarrow bar{K}^*(892)f_0(500)$ decays, respectively. The corresponding results are $mathcal{A_{CP}}(bar{B}^0rightarrow bar{K}_0^*(700)rho^0(770)) in [0.20, 0.36]$, $mathcal{A_{CP}}(bar{B}^0rightarrow bar{K}^*(892)f_0(500))in [0.08, 0.12]$, $mathcal{B} (bar{B}^0rightarrow bar{K}_0^*(700)rho^0(770)in [6.76, 18.93]times10^{-8}$ and $mathcal{B} (bar{B}^0rightarrow bar{K}^*(892)f_0(500))in [2.66, 4.80]times10^{-6}$, respectively, indicating the $CP$ violations of these two two-body decays are both positive and the branching fractions are quite different. These studies provide a new way to investigate the aforementioned four-body decay and could be helpful in clarifying the configuration of the structure of light scalar meson.
The decays $B^0_s rightarrow J/psi pi^+pi^- K^+ K^-$ are studied using a data set corresponding to an integrated luminosity of 9fb$^{-1}$, collected with the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13TeV. The decays $B^0_s rightarrow J/psi K^{ast0} bar{K}^{ast0}$ and $B^0_s rightarrow chi_{c1}(3872)K^+K^-$, where the $K^+K^-$ pair does not originate from a $phi$ meson, are observed for the first time. Precise measurements of the ratios of branching fractions between intermediate $chi_{c1}(3872)phi$, $J/psi K^{ast0}bar{K}^{ast0}$, $psi(2S)phi$ and $chi_{c1}(3872)K^+K^-$ states are reported. A structure, denoted as $X(4740)$, is observed in the $J/psiphi$ mass spectrum and, assuming a Breit-Wigner parameterisation, its mass and width are determined to be begin{eqnarray*} m_{X(4740)} & = & 4741 pm 6 pm 6,{mathrm{MeV}}/c^2 ,, Gamma_{X(4740)} & = & 53 pm 15 pm 11,{mathrm{MeV}} ,, end{eqnarray*} where the first uncertainty is statistical and the second is systematic. In addition, the most precise single measurement of the mass of the $B^0_s$ meson is performed and gives a value of $$ m_{B^0_s} = 5366.98 pm 0.07 pm 0.13,{mathrm{MeV}}/c^2,. $$
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
