arXiv subjects

Y. K. Hsiao

Publications and source records attributed to Y. K. Hsiao.

51 records · Page 3Linked to original sources

arXiv2014

Possibly New Charmed Baryon States from $\bar B^0\to p\bar p D^{0}$ Decay

We examine the invariant mass spectrum of $D^{0}p$ in $\bar B^0\to p\bar p D^{0}$ decay measured by BABAR and find that through the 2-step processes of $\bar B^0\to {\bf B_c^+}(\to D^{0} p)\bar p$, where ${\bf B_c}$ denotes a charmed baryon state, some of the peaks can be identified with the established $Σ_c(2800)^+$, $Λ_c(2880)^+$ and $Λ_c(2940)^+$. Moreover, in order to account for the measured spectrum, it is necessary to introduce a new charmed baryon resonance with $(m,\,Γ)=(3212\pm 20,\,167\pm 34)$ MeV.

hep-ph↗

arXiv2013

Identifying Glueball at 3.02 GeV in Baryonic $B$ Decays

We examine the nature of the unknown enhancement around 3 GeV observed by the BABAR collaboration in the $m_{p\bar p}$ spectrum of the $\bar B^0\to p\bar p D^0$ decay. Suspecting that the peak is a resonance, which can be neither identified as a charmonium state, such as $η_c$ or $J/ψ$, nor classified as one of the light-flavor mesons, we conclude that it corresponds to a glueball fitted as X(3020) with $(m_X,\;Γ_X)=(3020\pm 8,\; 107\pm 30)\;\text{MeV}$, which could be the first glueball state above 3 GeV. This state also appears in the $m_{p\bar p}$ spectrum of the $\bar B^0\to p\bar p D^{*0}$ decay.

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arXiv2012

Rare $B^-\toΛ\bar{p}ν\barν$ decay

We study the four-body semileptonic baryonic decay of $B^-\to Λ\bar pν\bar ν$ in the standard model. We find that the decay branching ratio is $(7.9\pm 1.9)\times 10^{-7}$. Similar to the rare decays of $B^-\to K^{(*)-}ν\bar ν$, this baryonic decay of $B^-\to Λ\bar pν\bar ν$ is also sensitive to new physics and accessible to the future $B$ factories.

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arXiv2011

Semileptonic $B-\to p\bar{p} \ell-\barν_\ell$ decays

We study the four-body exclusive semileptonic baryonic $\bar B$ decays of $B^-\to p\bar p \ell^- \barν_{\ell}$ ($\ell=e,μ,τ$) in the standard model. We find that their decay branching ratios are about $(1.0, 1.0,0.5)\times 10^{-4}$, respectively. In particular, the electron mode is close to the corresponding CLEO's upper limit of $5.2\times 10^{-3}$, while all results are about one or two orders of magnitude larger than the previous estimated values for the inclusive modes of $\bar B\to {\bf B\bar B'}\ell \bar ν$. Clearly, both B-factories of Belle and BaBar should be able to observe these exclusive four-body modes.

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arXiv2011

Study of $\bar B\to Λ\bar p\,ρ(ϕ)$ and $\bar B\to Λ\bar Λ\bar K^{*}$

We examine the three-body baryonic $\bar B\to {\bf B\bar B'}V$ decays with $V$ vector mesons in the standard model. We can simultaneously explain the recent experimental data on the decays of $B^-\to Λ\bar p \,ρ^0$ and $\bar B\to Λ\bar Λ\bar K^{*}$ based on the QCD counting rules and SU(3) flavor symmetry. We also predict that the decay branching ratios of $\bar B^0\to Λ\bar p \,ρ^+$ and $B^-\to Λ\bar p \,ϕ$ are 3.0 and $1.5\times 10^{-6}$, respectively, which are promising to be observed by BELLE and BABAR at the $B$ factories.

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arXiv2008

Charmful Three-body Baryonic B decays

We study the charmful three-body baryonic B decays with $D^{(*)}$ or $J/Ψ$ in the final state. We explain the measured rates of $\bar B^0\to n\bar p D^{*+}$, $\bar B^0\to p\bar p D^{(*)0}$, and $B^-\to Λ\bar p J/Ψ$ and predict the branching fractions of $\bar B^0\to Λ\bar p D^{*+}$, $\bar B^0\to Σ^0\bar p D^{*+}$, $B^-\toΛ\bar p D^{0}$, and $B^-\toΛ\bar p D^{*0}$ to be of order $(1.2, 1.1, 1.1, 3.9)\times 10^{-5}$, respectively. They are readily accessible to the $B$ factories.

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arXiv2007

Direct CP and T Violation in Baryonic B Decays

We review the direct CP and T violation in the three-body baryonic B decays in the standard model. In particular, we emphasize that the direct CP violating asymmetry in $B^\pm\to p\bar p K^{*\pm}$ is around 22% and the direct $T$ violating asymmetry in $\bar B^0 \ra Λ\bar p π^+$ can be as large as 12%, which are accessible to the current B factories at KEK and SLAC as well as SuperB and LHCb.

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arXiv2007

Study of $B\to p\bar{p}K^*$ and $B\to p\bar{p}ρ$

We study the three-body baryonic B decays of $B\to p\bar{p}(K^{*},ρ)$ in the standard model. The baryonic matrix elements are calculated in terms of the SU(3) flavor symmetry and the QCD power counting rules within the the perturbative QCD. We find that the decay branching ratios, angular and direct CP asymmetries of ($B^{-}\to p\bar{p}K^{*-}, \bar{B}^{0}\to p\bar{p}K^{*0}, B^{-}\to p\bar{p}ρ^{-}$) are around $(6,1,30)\times 10^{-6}$, $(13,-27,11)%$ and $(22,1,-3)%$, which are consistent with the current BaBar and Belle data, respectively. The large values of the branching ratio in $B^{-}\to p\bar{p}ρ^{-}$ and the direct CP asymmetry in $B^{\pm}\to p\bar{p}K^{*\pm}$ are useful to test the standard model and search for new physics.

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arXiv2007

Determination of Nucleon Form factors from Baryonic B Decays

It is the first time that the study of three-body baryonic B decays offers an independent determination of the nucleon form factors for the time-like four momentum transfer $(t>0)$ region, such as $G^{p,n}_M(t)$ of vector currents and those of axial ones. Explicitly, from the data of $\bar B^0\to n\bar p D^{*+}$ and $Λ\bar pπ^+$ we find a constant ratio of $G^n_M(t)/G^p_M(t)=-1.3\pm0.4$, which supports the FENICE experimental result. The vector and axial-vector form factors of $p\bar n$, $p\bar p$ and $n\bar n$ pairs due to weak currents are also presented, which can be tested in future experiments.

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arXiv2006

Direct CP violation in $B^\pm\to p \bar{p} K^{(*)\pm}$

We study the direct CP violation in $B^\pm\to p\bar p K^{(*)\pm}$ decays in the standard model. We point out that these three-body baryonic B decays can be important tools for detecting the direct CP violation in the charged $B$ system, in which there are no conclusive signatures yet. In particular, we show that the direct CP violating asymmetry in $B^\pm\to p\bar p K^{*\pm}$ is around 22% which supports the recent data by the BABAR Collaboration.

hep-ph↗

arXiv2006

Angular distributions in three-body baryonic B decays

We study the angular distributions of the baryon-antibaryon low-mass enhancements in the three-body baryonic B decays of $B\to p\bar{p}M$ (M=K and $π$) in the framework of the perturbative QCD. By writing the most general forms for the transition form factors of $B\to p\bar{p}$, we find that the angular distribution asymmetry in $B^-\to p\bar{p}K^-$ measured by the Belle Collaboration can be explained. We give a quantitative description on the Dalitz plot asymmetry in $B^-\to p\bar{p}K^-$ shown by the BaBar Collaboration and demonstrate that it is equivalent to the angular asymmetry. In addition, we present our results on $\bar B^0\to p\bar{p}K_S$ and $B^-\to p\bar{p}π^-$ and we obtain that their angular asymmetries are $-0.35\pm0.11$ and $0.45\pm0.10$, respectively, which can be tested by the ongoing experiments at the B factories.

hep-ph↗

arXiv2005

Constraints on the new particle in $Σ^+\to pμ^+μ^-$

The HyperCP collaboration has presented the branching ratio of $Σ^+\to pμ^+μ^-$ to be $(8.6^{+6.6}_{-5.4}\pm 5.5)\times 10^{-8}$ and suggested a new boson $P^0$ with a mass of $214.3\pm 0.5$ MeV to induce the flavor changing transition of $s\to dμ^+μ^-$. We demonstrate that to explain the data, the new particle cannot be a scalar but pseudoscalar based on the direct constraints from $K^+\toπ^+μ^+μ^-$ and $K_L\toμ^+μ^-$, respectively. Moreover, we determine that the decay width of the pseudoscalar should be in the range of $10^{-7}$ MeV with the lifetime of $10^{-14}$ sec.

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arXiv2005

T Violation in Baryonic B Decays

We study $T$ violation in the three-body charmless baryonic decay of $\bar B^0 \ra Λ\bar p π^+$ through the $T$-odd triple product correlation in the standard model. We find that the $T$ violating asymmetry is 10%, which is accessible to the current B factories at KEK and SLAC, while the CP violating one 1.1%. We emphasize that this triple product correlation would be the first measurable direct $T$ violating effect predicted in the standard model.

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arXiv2005

Study of $B\to Λ\barΛK$ and $B\to Λ\barΛπ$

We study three-body charmless baryonic B decays of $B \to Λ\barΛP$ with $P=π$ and $K$ in the standard model. We find that the branching ratios of the $K$ modes are about one order of magnitude larger than those of the corresponding $π$ modes unlike the cases of $B\to p\bar p P$. Explicitly, we obtain that $Br(B^-\to Λ\bar ΛK^-)=(2.8\pm 0.2)\times 10^{-6}$ and $Br(\bar B^0 \toΛ\bar Λ\bar K^0)=(2.5\pm 0.3)\times 10^{-6}$. The former agrees well with the BELLE experimental measurement of $(2.91^{+0.90}_{-0.70}\pm 0.38)\times 10^{-6}$, while the latter should be seen at the ongoing B factories soon.

hep-ph↗

arXiv2005

Radiative Baryonic $B$ Decays

We study the structure-dependent contributions to the radiative baryonic $B$ decays of $B \to {\bf B}{\bf \bar B'}γ$ in the standard model. We show that the decay branching ratios of $Br(B \to {\bf B}{\bf \bar B'}γ)$ are $O(10^{-7})$, which are larger than the estimated values of $O(10^{-9})$ induced from inner bremsstrahlung effects of the corresponding two-body modes. In particular, we find that $Br(B^- \to Λ\bar p γ)$ is around $1 \times 10^{-6}$, which is close to the pole model estimation but smaller than the experimental measurement from BELLE.

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