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تسجيل مستخدم جديدUnparticle effect on B_s - bar B_s mixing and its implications for B_s to J/psi phi, phi phi decays
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We study the effect of unparticle stuff on $B_s - bar{B}_s$ mixing and consider possible implications of it for the decaymodes $B_s to J/psi phi$ and $phi phi$. We find that due to the new contributions from the unparticles the $B_s - bar{B}_s$ mixing phase could be observable at the LHC along with the possible sizable CP asymmetry parameters $S_{psi phi(phi phi)}$ in $B_s to J/psi phi(phi phi)$ decay modes.
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The $B_s^0 rightarrow J/psi phi phi$ decay is observed in $pp$ collision data corresponding to an integrated luminosity of 3 fb$^{-1}$ recorded by the LHCb detector at centre-of-mass energies of 7 TeV and 8 TeV. This is the first observation of this
decay channel, with a statistical significance of 15 standard deviations. The mass of the $B_s^0$ meson is measured to be $5367.08,pm ,0.38,pm, 0.15$ MeV/c$^2$. The branching fraction ratio $mathcal{B}(B_s^0 rightarrow J/psi phi phi)/mathcal{B}(B_s^0 rightarrow J/psi phi)$ is measured to be $0.0115,pm, 0.0012, ^{+0.0005}_{-0.0009}$. In both cases, the first uncertainty is statistical and the second is systematic. No evidence for non-resonant $B_s^0 rightarrow J/psi phi K^+ K^-$ or $B_s^0 rightarrow J/psi K^+ K^- K^+ K^-$ decays is found.
A measurement of the decay time dependent CP-violating asymmetry in $B_s^0 to phiphi$ decays is presented, along with measurements of the $T$-odd triple-product asymmetries. In this decay channel, the CP-violating weak phase arises from the interfere
nce between $B_s^0$-$bar{B}_s^0$ mixing and the loop-induced decay amplitude. Using a sample of proton-proton collision data corresponding to an integrated luminosity of $3.0, fb^{-1}$ collected with the LHCb detector, a signal yield of approximately 4000 $B_s^0 to phiphi$ decays is obtained. The CP-violating phase is measured to be ${phi_s =-0.17pm0.15mathrm{,(stat)}pm0.03mathrm{,(syst)}}$ rad. The triple-product asymmetries are measured to be ${A_U=-0.003pm0.017mathrm{,(stat)}pm0.006mathrm{,(syst)}}$ and ${A_V=-0.017pm0.017mathrm{,(stat)}pm0.006mathrm{,(syst)}}$. Results are consistent with the hypothesis of CP conservation.
A first flavour-tagged measurement of the time-dependent CP-violating asymmetry in $B_s^0 to phiphi$ decays is presented. In this decay channel, the CP-violating weak phase arises due to CP violation in the interference between $B_s^0$-$bar{B}_s^0$ m
ixing and the $b to s bar{s} s $ gluonic penguin decay amplitude. Using a sample of $pp$ collision data corresponding to an integrated luminosity of $1.0; fb^{-1}$ and collected at a centre-of-mass energy of $7 rm TeV$ with the LHCb detector, $880 B_s^0 to phiphi$ signal decays are obtained. The CP-violating phase is measured to be in the interval [-2.46, -0.76] rm rad$ at 68% confidence level. The p-value of the Standard Model prediction is 16%.
Using a dataset corresponding to an integrated luminosity of 3.0 fb$^{-1}$ collected in $pp$ collisions at centre-of-mass energies of 7 and 8 TeV, the $B_s^0 to phi phi$ branching fraction is measured to be [ mathcal{B}(B_s^0 to phi phi) = ( 1.84 pm
0.05 (text{stat}) pm 0.07 (text{syst}) pm 0.11 (f_s/f_d) pm 0.12 (text{norm}) ) times 10^{-5}, ] where $f_s/f_d$ represents the ratio of the $B_s^0$ to $B^0$ production cross-sections, and the $B^0 to phi K^*(892)^0$ decay mode is used for normalization. This is the most precise measurement of this branching fraction to date, representing a factor five reduction in the statistical uncertainty compared with the previous best measurement. A search for the decay $B^0 to phi phi$ is also made. No signal is observed, and an upper limit on the branching fraction is set as [ mathcal{B}(B^0 to phi phi) < 2.8 times 10^{-8} ] at 90% confidence level. This is a factor of seven improvement compared to the previous best limit.
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