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Takayuki Matsuki

Publications and source records attributed to Takayuki Matsuki.

At least 73 records · Page 4Linked to original sources
arXiv2013

Reproducing the $Z_c(3900)$ structure through the initial-single-pion-emission mechanism

Being stimulated by the recent BESIII observation of a charged charmoniumlike structure $Z_c(3900)$, in this work we study the distributions of the $J/ψπ^\pm$ and $π^+π^-$ invariant mass spectra of the $Y(4260)\to π^+π^- J/ψ$ decay by the initial-single-pion-emission mechanism, where the interference effects of the ISPE mechanism with two other decay modes are also taken into account. The obtained $dΓ(Y(4260)\to π^+π^- J/ψ)/dm_{J/ψπ^\pm}$ and $dΓ(Y(4260)\to π^+π^- J/ψ)/dm_{π^+ π^-}$ marvelously agree with the BESIII data to reproduce the $Z_c(3900)$ structure.

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arXiv2013

Novel charged charmoniumlike structures in the hidden-charm dipion decays of Y(4360)

Studying the hidden-charm dipion decays of the charmoniumlike state Y(4360), we show that there exist charged charmoniumlike structures near $D\bar{D}^*$ and $D^*\bar{D}^*$ thresholds in the $J/ψπ^+$, $ψ(2S)π^+$ and $h_c(1P)π^+$ invariant mass spectra of the corresponding hidden-charm dipion decays of Y(4360) using the {\it{Initial Single Pion Emission} mechanism}. We suggest to do further experimental study on these predicted charged enhancement structures, especially by BESIII, Belle, and the forthcoming BelleII.

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arXiv2013

Predictions of charged charmonium-like structures with hidden-charm and open-strange channels

We propose the initial single chiral particle emission mechanism, with which the hidden-charm di-kaon decays of higher charmonia and charmonium-like states are studied. Calculating the distributions of differential decay width, we obtain the line shape of the $J/ψK^+$ invariant mass spectrum of $ψ_i\to J/ψK^+K^-$, where $ψ_i=ψ(4415), Y(4660)$, and $ψ(4790)$. Our numerical results show that there exist enhancement structures with both hidden-charm and open-strange decays, which are near the $D\bar{D}_s^*/D^*\bar{D}_s$ and $D^*\bar{D}_s^*/\bar{D}^*{D}_s^*$ thresholds. These charged charmonium-like structures predicted in this Letter can be accessible in future experiments, especially BESIII, BelleII, and SuperB.

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arXiv2013

Anomalous radiative transitions between $h_b(nP)$ and $η_b(mS)$ and hadronic loop effect

In this work, we introduce the hadronic loop contribution to explain the anomalous radiative transitions between $h_b(nP)$ and $η_b(mS)$, which was recently observed by the Belle Collaboration. Our calculation shows that the hadronic loop mechanism associated with these known decay mechanisms can explain why there exist anomalous radiative transitions between $h_b(nP)$ and $η_b(mS)$. This study deepens our understanding of the decay mechanism of higher bottomonium radiative decays.

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arXiv2013

η transitions between charmonia with meson loop contributions

We study the $η$ transitions between $ψ(4040/4160)$ and $J/ψ$ by introducing charmed meson loops in an effective Lagrangian approach to enhance the decay amplitudes. The branching fractions $\mathcal{B}[ψ(4040) \to J/ψη]$ and $\mathcal{B}[ψ(4160) \to J/ψη]$ estimated in this paper can remarkably explain the experimental measurements of Belle and BESIII within a reasonable parameter range. The $η^\prime$ transition between $ψ(4160)$ and $J/ψ$ is also investigated, and the branching fraction is under the upper limit of CLEO, which can be tested by future experiments.

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arXiv2012

Does the enhancement observed in $γγ\to D\bar{D}$ contain two $P$-wave higher charmonia?

Solved is a new puzzle raised by the observation of an enhancement structure Z(3930) in $γγ\to D\bar{D}$. If categorizing Z(3930) as $χ_{c2}(2P)$ suggested by Belle and BaBar, we must explain why $χ_{c0}(2P)$ dominantly decaying into $D\bar{D}$ is missing in the $D\bar{D}$ invariant mass spectrum. In this work, we propose that the Z(3930) enhancement structure may contain two $P$-wave higher charmonia {$χ_{c0}(2P)$} and $χ_{c2}(2P)$. We show that this assumption is supported by our analysis of the $D\bar{D}$ invariant mass spectrum and $\cosθ^\ast$ distribution of $γγ\to D\bar{D}$. This observation would not only provide valuable information of two P-wave higher charmonia $χ_{c0}(2P)$ and $χ_{c2}(2P)$, but also serve as the crucial test of our novel proposal to the observed enhancement structure Z(3930), especially at the forthcoming BelleII and the approved SuperB.

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arXiv2012

Interpretation of $Z_b(10610)$ and $Z_b(10650)$ in the ISPE mechanism and the Charmonium Counterpart

The initial single pion emission (ISPE) mechanism is applied to the processes $Υ(5S)\to πB^{(*)}\bar{B}^{(*)}$ whose details have been recently reported at ICHEP2012 and we obtain reasonable agreement with Bell's measurements, i.e., we succeed in reproducing the enhancement structures of $Z_b(10610)$ and $Z_b(10650)$. Inspired by this success, we predict the corresponding enhancement structures in higher charmonia open charm pion decay near the thresholds of $D^\ast \bar{D}$ and $D^\ast \bar{D}^\ast$.

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arXiv2012

Two charged strangeonium-like structures observable in the $Y(2175) \to ϕ(1020)π^{+} π^{-}$ process

Via the Initial Single Pion Emission (ISPE) mechanism, we study the $ϕ(1020)π^{+}$ invariant mass spectrum distribution of $Y(2175) \to ϕ(1020)π^{+} π^{-}$. Our calculation indicates there exist a sharp peak structure ($Z_{s1}^+$) close to the $K\bar{K}^\ast$ threshold and a broad structure ($Z_{s2}^+$) near the $K^\ast\bar{K}^\ast$ threshold. In addition, we also investigate the $ϕ(1680) \to ϕ(1020)π^{+} π^{-}$ process due to the ISPE mechanism, where a sharp peak around the $K\bar{K}^\ast$ threshold appears in the $ϕ(1020)π^{+}$ invariant mass spectrum distribution. We suggest to carry out the search for these charged strangeonium-like structures in future experiment, especially Belle II, Super-B and BESIII.

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arXiv2012

Non-strange partner of strangeonium-like state Y(2175)

Inspired by the observed Y(2175) state, we predict its non-strange partner Y(1915), which has a resonance structure with mass around 1915 MeV and width about $317\sim 354$ MeV. Experimental search for Y(1915) is proposed by analyzing the $ωf_0(980)$ or $ωππ$ invariant mass spectrum of the $e^+e^-\to ωf_0(980), ωππ$ and $J/ψ\to ηωf_0(980)$ processes, which are accessible at Belle, BaBar, BESIII and forthcoming BelleII. Considering similarity between two families, the comparison of the mass spectra of $ω$ and $ϕ$ families can provide important information on the 1D state of $ϕ$ family, $ϕ(1910)$, which has a very broad resonance structure with mass around 1910 MeV regarded as the strangeonium partner of $ω(1650)$. This also answers the question why the 1D state $ϕ(1910)$ is still missing in experiment. This is supported by our former study on the properties of Y(2175), which explains Y(2175) as the 2D strangeonium because our theoretical total width is comparable with the Belle data.

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arXiv2011

Chiral Particle Decay of Heavy-Light Mesons in a Relativistic Potential Model

Partial decay widths of the heavy-light mesons, $D, D_s, B,$ and $B_s$, emitting one chiral particle ($π$ or $K$) are evaluated in the framework of a relativistic potential model. Decay amplitudes are calculated by keeping the Lorentz invariance as far as possible and use has been made of the Lorentz-boosted relativistic wave functions of the heavy-light mesons. One of predictions of our calculation is very narrow widths of a few keV for yet undsicovered $B_s(0^+, 1^+)$ mesons corresponding to ${^{2S+1}L_J}={^3P_0}$ and $"{^3P_1}"$ assuming their masses to be 5617 and 5682 MeV, respectively, as calculated in our former paper. In the course of our calculation, new sum rules are discovered on the decay widths in the limit of $m_Q\to \infty$. Among these rules, $ Γ(D_{s0}^*(2317)\to D_s+π)=Γ(D_{s1}(2460)\to D_s^*+π) $ and $ Γ(B_{s0}^*(5615)\to B_s+π)=Γ(B_{s1}(5679)\to B_s^*+π) $ are predicted to hold with a good accuracy.

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arXiv2011

Charged bottomonium-like structures in the hidden-bottom dipion decays of $Υ(11020)$

Under the Initial Single Pion Emission mechanism, we study the hidden-bottom dipion decays of $Υ(11020)$, i.e., $Υ(11020)\to Υ(nS)π^+π^-$ $(n=1,2,3)$ and $Υ(11020)\to h_b(mP)π^+π^-$ $(m=1,2)$. We predict explicit sharp peak structures close to the $B\bar{B}^*$ and $B^*\bar{B}^*$ thresholds and their reflections in the $Υ(1S)π^+$, $Υ(2S)π^+$ and $h_b(1P)π^+$ invariant mass spectrum distributions. We suggest future experiment, i.e., Belle, BaBar, and forthcoming BelleII or Super-B, carry out the search for these novel phenomena, which can provide important test to the Initial Single Emission mechanism existing in higher bottomonia.

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arXiv2010

Newly observed D(2550), D(2610), and D(2760) as 2S and 1D charmed mesons

We study three newly observed D(2550), D(2610), and D(2760) by the BaBar Collaboration utilizing the mass spectra and investigating the strong decays. Our calculation indicates that D(2610) is an admixture of $2^3S_1$ and $1^3D_1$ with $J^P=1^-$. $D(2760)$ can be explained as either the orthogonal partner of D(2610) or $1^3D_3$. Our estimate of the decay width for $D(2550)$, assuming it as $2^1S_0$, is far below the experimental value. the threshold effect because the strong decay of $D(2550)\to D_0^*π$ is forbidden.} The decay behavior of the remaining two 1D charmed mesons, i.e., $^3D_2$ and $^1D_2$ ($J^P=2^-$) states, is predicted, which will help future experimental search for these missing $D$-wave charmed mesons.

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arXiv2010

Decay properties of the heavy-light mesons

We study the decay properties of a heavy-light meson. We reformulate the decay amplitudes for the heavy-light systems and find a new way to calculate decay rates. Applying this formulation, we find a new sum rule for the radiative decays of one heavy-light meson into another, $H_1\to H_2+γ$ with various combinations of $H_i$.

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arXiv2010

Mixing angle between $^3P_1$ and $^1P_1$ in HQET

Some claim that there are two independent mixing angles ($θ= 35.3^\circ$, $-54.7^\circ$) between $^3P_1$ and $^1P_1$ states of heavy-light mesons in heavy quark symmetric limit, and others claim there is only one ($θ= 35.3^\circ$). We clarify the difference between these two and suggest which should be adopted. General arguments on the mixing angle between $^3L_L$ and $^1L_L$ of heavy-light mesons are given in HQET and a general relation is derived in heavy quark mass limit as well as that including the first order correction in $1/m_Q$.

hep-ph↗
arXiv2008

Is the Z^+(4430) a radially excited state of D_s?

We present the interpretation that the recently discovered Z^+(4430) by the Belle Collaboration can be a radial excitation of the cs-bar state. We give an explicit cs-bar candidate for this state by calculating the mass value in our semirelativistic quark potential model and also give a natural interpretation on the reason why the decay mode Z-> J/ψπ^+ has not yet been seen while Z-> ψ' πcan be seen.

hep-ph↗
arXiv2007

Study of Structure of the Mass Gap between Two Spin Multiplets

Studying our semirelativistic potential model and the numerical results, which succeeds in predicting and reproducing recently discovered higher resonances of $D$, $D_s$, $B$, and $B_s$, we find a simple expression for the mass gap between two spin multiplets of heavy-light mesons, $(0^-,1^-)$ and $(0^+,1^+)$. The mass gap between chiral partners defined by $ΔM=M(0^+)-M(0^-)$ and/or $M(1^+)-M(1^-)$ is given by $ΔM=M(0^+)-M(0^-)=M(1^+)-M(1^-)\approx Λ_{\rm Q}-m_q$ in the limit of heavy quark symmetry. We also study the case including $1/m_Q$ corrections.

hep-ph↗
arXiv2007

Structure of Mass Gap between Two Spin Multiplets

Studying our semirelativistic potential model and the numerical results, which succeeds in predicting and reproducing recently discovered higher resonances of $D$, $D_s$, $B$, and $B_s$, we find a simple expression for the mass gap between two spin multiplets of heavy-light mesons, $(0^-,1^-)$ and $(0^+,1^+)$. The mass gap between chiral partners defined by $ΔM=M(0^+)-M(0^-)$ and/or $M(1^+)-M(1^-)$ is given by $ΔM=M(0^+)-M(0^-)=M(1^+)-M(1^-)\approx Λ_{\rm Q}-m_q$ in the limit of heavy quark symmetry, and including $1/m_Q$ corrections, we have $ΔM\approx Λ_{\rm Q}-m_q+(1.28\times 10^{5}+4.26\times 10^{2}\cdot m_q)/m_Q$ with $Λ_{\rm Q}\approx 300$ MeV, a light quark mass $m_q$, and a heavy quark mass $m_Q$. This equation holds both for $D$ and $D_s$ heavy mesons. Our model calculations for the $B$ and $B_s$ also follow this formula.

hep-ph↗
arXiv2007

Construction of Lorentz Invariant Amplitudes from Rest Frame Wave Functions in HQET

Succeeding in predicting 0^+ and 1^+ states of D and D_s heavy mesons by our semi-relativistic quark potential model, we examine a method how to construct Lorentz-invariant scattering amplitudes and/or decay widths and develop a formulation to calculate Lorentz-boosted ones given the rest frame wave functions in our model. To show how effective this is, we apply the formulation to calculate the semileptonic weak form factors out of the rest frame wave functions of heavy mesons and numerically calculate the dynamical 1/m_Q corrections to those for the process B-bar -> D^{(*)}\ellνbased on our model for heavy mesons. It is shown that nonvanishing expressions for ρ_1(ω)=ρ_2(ω) and ρ_3(ω)=ρ_4(ω)=0 are obtained in a special Lorentz frame, where ρ_i(ω) are the parameters used in the Neubert-Rieckert decomposition of form factors. Various values of form factors are estimated, which are compatible with recent experimental data as well as other theoretical calculations.

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