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Register a new userDetecting the polarization in $chi_{cJ} to phi phi $ decays to probe hadronic loop effect
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In this work, we propose that detecting the polarization information of $chi_{cJ}to phiphi~(J=0,1,2)$ can be as good test of the role of hadronic loop effect on these decays. Our results shows that the obtained ratios of helicity amplitudes are quite stable, which are $|F_{1,1}^{(0)}/F_{0,0}^{(0)}| approx 0.359$, $|F_{1,0}^{(1)}/F_{0,1}^{(1)}| =1$, $|F_{1,1}^{(1)}/F_{0,1}^{(1)}| =0$, $|F^{(2)}_{1,0}|/|F^{(2)}_{0,0}|=|F^{(2)}_{0,1}|/|F^{(2)}_{0,0}| approx 1.285,~|F^{(2)}_{1,-1}|/|F^{(2)}_{0,0}|=|F^{(2)}_{-1,1}|/|F^{(2)}_{0,0}| approx 5.110$ and $|F^{(2)}_{-1,-1}|/|F^{(2)}_{0,0}|=|F^{(2)}_{1,1}|/|F^{(2)}_{0,0}| approx 0.465$. By adopting these predicted ratios, we further generate Monte-Carlo events of moments $langle t_{ij} rangle$, which are directly related to the determination of helicity amplitudes. We suggest further experiments like BESIII and Belle II to perform an analysis on the polarizations of the $chi_{cJ}to phiphi$ process in the future, which is important to understand the underlying decay mechanism existing in $chi_{cJ}$ decays.
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Using a data sample of $(448.1pm2.9)times10^{6}$ $psi(3686)$ decays collected by the BESIII detector at the Beijing Electron Positron Collider (BEPCII), we observe the decays $chi_{cJ}to phiphieta~(J=0,~1,~2)$, where the $chi_{cJ}$ are produced via the radiative processes $psi(3686)togammachi_{cJ}$. The branching fractions are measured to be $mathcal B(chi_{c0}tophiphieta)=(8.41pm0.74pm0.62)times10^{-4}$, $mathcal B(chi_{c1}tophiphieta)=(2.96pm0.43pm0.22)times 10^{-4}$, and $mathcal B(chi_{c2} to phiphieta)=(5.33pm0.52pm0.39) times 10^{-4}$, where the first uncertainties are statistical and the second are systematic. We also search for intermediate states in the $phiphi$ or $etaphi$ combinations, but no significant structure is seen due to the limited statistics.
We perform a theoretical study of the $chi_{cJ} to phi K^* bar K to phi Kpi bar K$ reaction taking into account the $K^* bar K$ final state interaction, which in the chiral unitary approach is responsible, together with its coupled channels, for the formation of the low lying axial vector mesons, in this case the $h_1(1380)$ given the selection of quantum numbers. Based on this picture we can easily explain why in the $chi_{c0}$ decay the $h_1(1380)$ resonance is not produced, and, in the case of $chi_{c1}$ and $chi_{c2}$ decay, why a dip in the $K^+ pi^0 K^-$ mass distribution appears in the 1550-1600 MeV region, that in our picture comes from a destructive interference between the tree level mechanism and the rescattering that generates the $h_1(1380)$ state. Such a dip is not reproduced in pictures where the nominal $h_1(1380)$ signal is added incoherently to a background, which provides support to the picture where the resonance appears from rescattering of vector-pseudoscalar components.
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.
Using a data sample of 106 million $psi(3686)$ events collected with the BESIII detector operated at the BEPCII storage ring, we study for the first time the decay $chi_{cJ}tophi K^{0}_S K^{pm}pi^{mp}$ and $chi_{cJ}tophi K^{+} K^{-}pi^{0}$ in the E1 radiative transition $psi(3686)togammachi_{cJ}$. The decays are dominated by the three-body decay $chi_{cJ}to phi K^*(892)bar{K}$. We measure branching fractions for this reaction via the neutral and charged $K^*(892)$ and find them consistent with each other within the expectation of isospin symmetry. In the $Kbar{K}pi$ invariant mass distribution a structure near the $K^*(892)bar{K}$ mass threshold is observed, and the corresponding mass and width are measured to be $1412pm4(mathrm{stat.})pm8(mathrm{sys.}) mathrm{MeV}/c^2$ and $Gamma$ = $84pm12(mathrm{stat.})pm40(mathrm{sys.}) mathrm{MeV}$, respectively. The observed state favors an assignment to the $h_1(1380)$, considering its possible $J^{PC}$ and comparing its mass, width and decay mode to those reported in the Particle Data Group.
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 interference 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.
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