R. M. Albuquerque, M. Nielsen
We correct a mistake in the analytical expression given in Nucl. Phys. {\bf A} 815, 53 (2009) [arXiv:0804.4817] for the $D_{s0}\bar{D}_s^*$ and $D_{0}\bar{D}^*$ molecular currents. As a consequence, the mass obtained for the $D_{0}\bar{D}^*$ molecular current: $m_{D_{0}\bar{D}^*}=(4.96\pm 0.11)$ GeV is no longer compatible with the experimental mass of the meson Y(4260).
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
继续探索
It is clearly demonstrated that numerical values of the $f^F, f^D$ and $f^S$ coupling constants in SU(3) invariant Lagrangian of the interaction of the vector-meson nonets with $1/2^+$ octet baryons do not depend on the chosen version of the $ω-ϕ$ mixing.
We correct a mistake in the calculation of meson masses at large baryon chemical potential made in hep-ph/9910491v2
In this paper leading twist light cone wave functions of 2S state charmonium mesons are studied and models of these functions are built.
The recent progress in experiments at B-factories suggests an opportunity to search for missing charmonium states $η_{c}'(2^1S_0)$ and $h_c(1^1P_1)$. The feasibility of such a search in B-meson decays are discussed.
We study mixing between conventional and hybrid mesons in vector and axial vector charmonium using QCD Laplace sum-rules. We compute meson-hybrid cross correlators within the operator product expansion, taking into account condensate contributions up to and including those of dimension-six as well as composite operator renormalization-induced diagrams. Using measured masses of charmonium-like states as input, we probe known resonances for nonzero coupling to both conventional and hybrid meson currents, a signal for meson-hybrid mixing.
In this paper, Schrodinger equation is numerically applied through non-relativistic potential model for deriving Spectrum, radial wave functions at origin, decay constants, lepton and photon decay widths for radial and orbital excited conventional as well as hybrid charmonium mesons. These calculated results are found in agreement with others theoretical results and with the experimental observations.
Semileptonic and nonleptonic decays of the B_c meson to charmonium and D mesons are studied in the framework of the relativistic quark model. The decay form factors are explicitly expressed through the overlap integrals of the meson wave functions in the whole accessible kinematical range. The relativistic meson wave functions are used for the calculation of the decay rates. The obtained results are compared with the predictions of other approaches.
Theoretical computations on the decays of $B_c$ meson to $P$-wave charmonium $χ_c$ or $h_c$ with some particle(s) else and on the decays of $B_c$ meson to leptons with gluon bremsstrahlung, and the results as well are outlined.
We present a systematic and selfconsistent analysis of four-quark charmonium states and applied it to study compact four-quark systems and meson-meson molecules. Our results are robust and should serve to clarify the situation of charmonium spectroscopy above the threshold production of charmed mesons.
We study $η_{\rm c}$- and $J/ψ$-isoscalar meson bound states in the hadro-charmonium picture. In the hadro-charmonium, the four $q\bar q c \bar c$ quarks are arranged in terms of a compact charm-anticharm pair, $c \bar c$, embedded in light hadronic matter, $q \bar q$, with $q = u$, $d$ or $s$. The interaction between the charmonium core and the light matter can be written in terms of the multipole expansion in QCD, with the leading term being the $E1$ interaction with chromo-electric field ${\bf E}^a$. The spectrum of $η_{\rm c}$- and $J/ψ$-isoscalar meson bound states is calculated and the r…
We outline a coherent strategy for exploring the four remaining narrow charmonium states [$η_{c}^{\prime}(2\slj{1}{1}{0})$, $h_{c}(1\slj{1}{2}{1})$, $η_{c2}(1\slj{1}{3}{2})$, and $ψ_{2}(1\slj{3}{3}{2})$] expected to lie below charm threshold. Produced in $B$-meson decays, these levels should be identifiable \textit{now} via striking radiative transitions among charmonium levels and in exclusive final states of kaons and pions. Their production and decay rates will provide much needed new tests for theoretical descriptions of heavy quarkonia.
In this paper the production of excited vector and pseudoscalar charmonium mesons in $\epem$ annihilation is analyzed in the framework of light cone. In particular the cross sections $\epem \to ψ(2S)η_c(1S), ψ(1S)η_c(2S),ψ(2S)η_c(2S)$ have been calculated. It is shown, that contrary to NRQCD the cross sections calculated in the framework of light cone agree with experimental data.
The study of electron-positron collisions at center-of-mass energies corresponding to charmonium production has reached new levels of sensitivity thanks to experiments by the BES and CLEO Collaborations. Final states $γP$, where $P$ is a pseudoscalar meson such as $π^0$, $η$, and $η'$ can arise either from charmonium decays or in the continuum through a virtual photon: $e^+ e^- \to γ^* \to γP$. Estimates of this latter process are given at center-of-mass (c.m.) energies corresponding to the $J/ψ(1S)$, $ψ(2S)$, and $ψ(3770)$ resonances.
The semileptonic decays of meson $B_c$ to a P-wave charmonium state $χ_c(^3P_J)$ or $h_c(^1P_1)$ are computed. The results show that the decays are sizable so they are accessible in Tevatron and in LHC, especially, with the detectors LHCB and BTeV in the foreseeable future, and of them, the one to the $^1P_1$ charmonium state potentially offers us a novel window to see the unconfirmed $h_c$ particle. In addition, it is pointed out that since the two charmonium radiative decays $χ_c(^3P_{1,2}) \to J/ψ+γ$ have sizable branching ratios, the cascade decays of the concerned decays and the charmoniu…
We calculate the next-to-leading order (NLO) quantum chromodynamics (QCD) corrections to inclusive processes $W^+\to J/ψ(η_c)+c+\bar{s}+X$ and $W^+\to B_c(B_c^{*})+b+\bar{s}+X$ in the framework of nonrelativistic QCD (NRQCD) factorization formalism. Result indicates that the NLO corrections are significant, and the uncertainties in theoretical predictions with NLO corrections are greatly reduced. The charmonium and $B_c$ meson yielding rates at the Large Hadron Collider (LHC) are given.
We present the semileptonic decay of $B_{c}$ meson in a QCD potential model with the coulombic part of the Cornell potential $-\frac{4α_{S}}{3r}+br+c$ as perturbation. Computing the slope and curvature of Isgur Wise function in this approach, we study the pseudoscalar and vector form factors for the transition of $B_{c}$ meson to its S wave charmonium $c\bar{c}$ states. Numerical estimates of widths for the transitions of $B_{c}\rightarrow J/ψ(η_{c})lν_{l}$ are presented. The results are found to be in good agreement with other theoretical values.
The total cross section of the process $e^+e^- \to Λ\barΛ$ is calculated within the energy range close to the mass of $ψ(3770)$ charmonium state. Two different contributions were considered: the $D$-meson loop and the three gluon charmonium annihilation one. Both of them contribute noticeably and in sum fairly reproduce the data. Large relative phase for these contributions are generated with respect to the pure electromagnetic mechanism. As a by product the fit for the electromagnetic form factor of $Λ$-hyperon is obtained for the large momentum transferred region.
$B$ meson decays to vector charmonium(like) states and a $K$ meson: the role of final-state interactions
本文计算了 $B$ 介子衰变到矢量粲偶素（类）态和 $K$ 介子的分支比，发现末态相互作用（长距离贡献）占主导，并指出 $\psi(4160)$ 可能具有奇特性质。
In this talk we present some recent studies of multiquark components in the charmonium sector. We study the possible existence of compact four quark-states and meson-meson molecules in the charmonium spectroscopy.
In this article, we assign the newly reported state $X(3842)$ to be a D-wave $\overline{c}c$ meson, and study its mass and decay constant with the QCD sum rules by considering the contributions of the vacuum condensates up to dimension-6 in the operator product expansion. The predicted mass $M_{X(3842)}=(3.844^{+0.0675}_{-0.0823}\pm0.020)GeV$ is in agreement well with the experimental data $M_{X(3842)}=(3842.71\pm0.16\pm0.12)MeV$ from the LHCb collaboration. This result supports assigning $X(3842)$ to be a $1^{3}D_{3}$ charmonium meson. As the $1^{3}D_{3}$ $\overline{c}c$ meson, its predicted …
From a diabatic bound state approach to $J^{PC}=1^{--}$ and $(0,1,2)^{++}$ charmoniumlike resonances below $4.1$ GeV, formulated in terms of ${c\overline{c}}$ and closed meson-meson channels, we calculate mass shifts and widths due to open meson-meson channels. This calculation does not involve any new free parameter, so comparison of our predictions with existing data provides a direct test of our approach. Further mass corrections are also estimated and good agreement with the measured masses comes out. As for the calculated widths, overall reasonable, they point out to the need of some refi…
Study on charmonium(-like) mesons within a diabatic approach
本研究用纳入自旋相关相互作用的绝热方法研究4.1GeV以下粲夸克偶素（类）介子谱，得到与实验吻合的质量及成分概率，支持部分态有显著分子成分，并提出两个候选态。
We study the exclusive decays of $B$ meson into P-wave charmonium states $χ_{cJ}(J=0,1)$ in the QCD factorization approach with light-cone distribution functions describing the mesons in the processes. For $B \to χ_{c1} K$ decay, we find that there are logarithmic divergences arising from nonfactorizable spectator interactions even at twist-2 order and the decay rate is too small to accommodate the experimental data. For $B\to χ_{c0} K$ decay, we find that aside from the logarithmic divergences arising from spectator interactions at leading-twist order, more importantly, the factorization will…
In this paper the processes $e^+ e^- \to J/ΨJ/Ψ, J/Ψψ', ψ' ψ'$ are considered in the framework of light cone formalism. An important distinction of this approach in comparison to the approaches used in other papers is that relativistic and leading logarithmic radiative corrections to the cross section can be easily resummed within light cone formalism. In this paper the effect of this resummation is studied. It is shown that this effect is important especially for the production of higher charmonium mesons. The predicted cross sections are in agreement with the upper bounds set by Belle collab…
The total cross section of the process $e^+e^- \to p\bar{p}$ is calculated within the energy range close to the mass of $ψ(3770)$ charmonium state. It was shown that the main contribution to this cross section comes from three gluon mechanism which is also responsible of the large phase with respect to the Born amplitude. This phase provides the characteristic dip behaviour of the cross section in contrast to the usual Breit-Wigner peak shape. OZI-allowed mechanism with D-mesons in the intermediate state was also estimated and gives relatively small contribution to the cross section and to the…
Spectrum of Hybrid Charmonium, Bottomonium and $B_c$ Mesons by Power Series Method
本文通过扩展势模型并结合格点数据，用幂级数法计算了混合粲偶素、底偶素和 $B_c$ 介子各态质量，并与理论和实验对比，为研究新发现的介子态提供参考。
We calculate the decay rates of $B$ mesons into P-wave charmonium states using new factorization formulas that are valid to leading order in the relative velocity of the charmed quark and antiquark and to all orders in the running coupling constant of QCD. We express the production rates for all four P states in terms of two nonperturbative parameters, the derivative of the wavefunction at the origin and another parameter related to the probability for a charmed-quark-antiquark pair in a color-octet S-wave state to radiate a soft gluon and form a P-wave bound state. Using existing data on $B$ …
The factorization of hard and soft contributions into the hadronic decays of B_c meson at large recoils is explored in order to evaluate the decay rates into the S, P and D-wave charmonia associated with rho and pi. The constraints of approach applicability and uncertainties of numerical estimates are discussed. The mode with the J/psi in the final state is evaluated taking into account the cascade radiative electromagnetic decays of excited P-wave states, that enlarges the branching ratio by 20-25%.
We apply the diabatic formalism, first introduced in molecular physics, to the description of heavy-quark mesons. In this formalism the dynamics is completely described by a diabatic potential matrix whose elements can be derived from unquenched lattice QCD studies of string breaking. For energies far below the lowest open flavor meson-meson threshold, the resulting diabatic approach reduces to the well-known Born-Oppenheimer approximation where heavy-quark meson masses correspond to energy levels in an effective quark-antiquark potential. For energies close below or above that threshold, wher…
K*-charmonium dissociation reactions in hadronic matter are studied in the Born approximation, in the quark-interchange mechanism, and with a temperature-dependent quark potential. We obtain the temperature dependence of unpolarized cross sections for K*-charmonium dissociation reactions which produce charmed mesons and charmed strange mesons. We use the cross sections for charmonium dissociation in collisions with pion, rho meson, kaon, vector kaon, and eta meson to calculate dissociation rates of charmonium with the five types of mesons. Because of the temperature dependence of the meson mas…
The associated production of a $J/ψ$ and a $π$-meson in antiproton-nucleon annihilation is studied in the framework of QCD collinear factorization. In this approach, a hard subprocess responsible for the production of the heavy quark-antiquark pair factorizes from soft hadronic matrix elements, such as the antiproton (nucleon) distribution amplitude and the nucleon-to-pion (antiproton-to-pion) transition distribution amplitude. This reaction mechanism should dominate the forward and backward kinematical regions, where the cross sections are expected to be measurable in the set-up of the PANDA …
The BESIII collaboration reported an observation of two charged charmonium-like structure $Z_c^{\pm}(3900)$ and $Z_c^{\pm}(4025)$ in $e^+e^- \to (J/ψπ)^{\pm} π^{\mp}$ and $e^+e^- \to (D^* {\bar D}^*)^{\pm} π^{\mp}$ at ${\sqrt s} =4.26$ GeV recently, which could be an analogue of $Z_b(10610)$ and $Z_b(10650)$ claimed by the Belle Collaboration. In this work, we investigate the hidden-charmonium transitions of $Z_c^{\pm}(3900)$ and $Z_c^{\pm}(4025)$ via intermediate $D^{(*)} {D}^{(*)}$ meson loops. Reasonable results for the branching ratios by taking appropriate values of $α$ in this model can …
The production of charmonium pentaquark from b-baryon and B-meson decay: SU(3) analysis
本研究基于味SU(3)对称性分析b重子与B介子产生粲偶素五夸克的衰变，参数化衰变振幅并推导宽度关系，结果可在未来对撞机实验中检验，助力新五夸克态或衰变道探索。
We consider the non-relativistic limit of the QCD Hamiltonian in the Coulomb gauge, to describe radiative transitions between conventional charmonium states and from the lowest multiplet of $c\bar{c}$ hybrids to charmonium mesons. The results are compared to potential quark models and lattices calculations.
In the X(3872) decay, both of the J/ψππ and J/ψπππ branching fractions are observed experimentally, and their sizes are comparable to each other. In order to clarify the mechanism to cause such a large isospin violation, we investigate X(3872) employing a model of coupled-channel two-meson scattering with a ccbar core. The two-meson states consist of D0Dbar*0, D+Dbar*-, J/ψρ, and J/ψω. The effects of the ρ and ω meson width are also taken into account. We calculate the transfer strength from the ccbar core to the final two-meson states. It is found that very narrow J/ψρ and J/ψω peaks appear v…
The charmonium dissociation by mesons in relativistic heavy-ion reactions is analyzed within the Regge approach. It is shown that the inclusion of the initial and final state interactions in the dissociation of J/Psi to bar{D}* D* close to threshold increases the cross section significantly and can not be neglected in comparison to the total dissociation rate. This is due to resonant bar{D}*-D* interactions in sqrt{s} close to the masses of the Psi(4.04) and Psi(4.16) mesons. We also investigate thermal effects of the (c bar{c}) width for such processes in the medium. All these effects change …
In this paper, masses and radii of $Σ^-_u$ states hybrid charmonium mesons are calculated by numerically solving the Schrödinger equation with non-relativistic potential model. Results for calculated masses of $Σ^-_u$ states charmonium hybrid mesons are found to be close to the results obtained through lattice simulations. Calculated masses are used to construct Regge trajectories. It is found that the trajectories are almost linear and parallel.
The effects of charmed meson loops on the spectrum of charmonium are considered, with special attention paid to the levels above open-charm threshold. It is found that the coupling to charmed mesons generates a structure at the D \bar{D}* threshold in the 1++ partial wave. The implications for the nature of the X(3872) state are discussed.
In the wake of recent measurements of ratios of semileptonic branching fractions: ${\cal R}_{J/ψ}, {\cal R}_D$ and ${\cal R}_{D^*}$ reported by the LHCb, BELLE and HFLAV Collaborations, we calculate invariant form factors for the exclusive semileptonic $B_c$-meson decays to radially excited charmonium and charm meson states in the full kinematical region within the framework of relativistic independent quark (RIQ)model. We evaluate the lepton mass effect in the decay processes induced by $b\to c,u$ transition at the quark level. Our predictions on branching fractions for $B_c\to η_c/ψ(nS)$ are…
In this article, we calculate the mass shift and decay constant of isospin averaged pseudoscalar ($D^+$,$D^0$) and scalar ($D^+_0$,$D^0_0$) mesons by the magnetic field induced quark and gluon condensates at finite density and temperature of asymmetric nuclear matter. We have calculated the in-medium chiral condensates from the chiral SU(3) mean field model and subsequently used these condensates in QCD Sum Rules (QCDSR) to calculate the effective mass and decay constant of $D$ mesons. Consideration of external magnetic field effects in hot and dense nuclear matter lead to appreciable modifica…
We review how quark models are able to describe the phenomenology of the charm meson sector. The spectroscopy and decays of charmonium and open charm mesons are described in a particular quark model and compared with the data and the results of other existing models in the literature. A quite reasonable global description of the heavy meson spectra is reached. A new assignment of the $ψ(4415)$ resonance as a 3D state leaving aside the 4S state to the X(4360) is tested through the analysis of the resonance structure in $e^{+}e^{-}$ exclusive reactions around the $ψ(4415)$ energy region. We make…
Recent data on charmonium production in B-meson decays suggest that charmonium hybrid mesons with mass ~4 GeV may be produced in B-decay via c\bar{c} colour octet operators. Some of these states are likely to be narrow with clean signatures to J/ψpi^+ pi^- final states. Experimental signatures and search strategies for existing B-factories are described.
Hybrid $ c \bar c g$ of quantum numbers $1^{--}$ are considered in a quark model with constituant quarks and gluon. The lowest $J^P=1^-$ states may be built in two ways, $l_g=1$ (gluon excited) corresponding to an angular momentum between the gluon and the $c \bar c$ system, while $l_{c\bar c}=1$ (quark excited) corresponds to an angular momentum between the $c$ and the $\bar c$. The lowest lying hybrid $J^P=1^-$ state in the flux tube model is similar to the $l_g=1$ in the quark-gluon model. In particular it verifies the selection rule that it cannot decay into two fundamental mesons. The $l_…
We apply perturbative QCD to the radiative decays of charmonia $J/ψ$ and $χ_{cJ}$ into light mesons. We perform a complete numerical calculation for the quark-gluon loop diagrams involved in these processes. The calculated $J/ψ$ decay branching ratios to P-wave mesons $f_2(1270)$ and $f_1(1285)$ fit the data well, while that of $f_0(980)$ (if treated as an $s\bar s$ meson) is predicted to be $1.6\times 10^{-4}$, which implies that $f_0(1710)$ can not be the $s\bar s$ or $(u\bar u+d\bar d)/\sqrt{2}$ meson. Decays of P-wave charmonia $χ_{cJ}\to ρ(ω, ϕ)γ$ (J=0,1,2) are also studied, and the branc…
We study the semileptonic decays of $B_c$ meson to S-wave charmonium states in the framework of relativistic independent quark model based on an average flavor-independent confining potential $U(r)$ in the scalar-vector harmonic form $U(r)=\frac{1}{2}(1+γ^0)(ar^2+V_0)$, where ($a$, $V_0$) are the potential parameters.The form factors for $B_c^+\to η_c /ψe^+ν_e$ transitions are studied in the physical kinematic range. Our predicted branching ratios (BR) for transitions to ground state charmonia are found comparatively large $\sim $ $10^{-2}$, compared to those for transitions to radially excite…
In this paper, we calculate the next-to-leading order (NLO) quantum chromodynamics (QCD) corrections to the exclusive processes $B_c^+\to χ_{cJ}(h_c)π^+$ in the framework of the nonrelativistic QCD (NRQCD) factorization formalism. The results show that NLO QCD corrections markedly enhance the branching ratios with $K$ factors of about 2.5. In combination with the study of $B_c^+\to J/ψπ^+$, we find that the NLO NRQCD prediction for the ratio of branching fractions $\frac{\mathcal{B}(B_c^+\to χ_{c0}π^+)}{\mathcal{B}(B_c^+\to J/ψπ^+)}$ is then compatible with the experimental measurement.
A diagrammatic approach to quark exchange processes in meson-meson scattering is applied to the case of inelastic reactions of the type $(Q\barQ)+(q\barq)\rightarrow (Q\barq) + (q\barQ)$, where $Q$ and $q$ refer to heavy and light quarks, respectively. This string-flip process is discussed as a microscopic mechanism for charmonium dissociation (absorption) in hadronic matter. The cross section for the reaction $J/ψ+ π\to D+ \bar D$ is calculated using a potential model, which is fitted to the meson mass spectrum. The temperature dependence of the relaxation time for the $\J/Psi$ distribution i…
We study kaon-charmonium and eta-charmonium dissociation reactions. The K-charmonium dissociation and the eta-charmonium dissociation include 27 reactions. Cross sections for the reactions are calculated in the Born approximation, in the quark-interchange mechanism and with a temperature-dependent quark potential. The temperature dependence of peak cross sections of endothermic reactions is linked to the temperature dependence of quark-antiquark relative-motion wave functions, meson masses and the quark potential. Although the eta meson and kaon have similar masses, the energy and temperature …
We use the framework of a relativistic constituent quark model to study the semileptonic transitions of the Bc meson into CCbar charmonium states where CCbar = etaC (1S0), J/psi (3S1), chiC0 (3P0), chiC1 (3P1), hc (1P1), chiC2 (3P2), psi (3D2). We compute the q^2-dependence of all relevant form factors and give predictions for their semileptonic Bc decay modes including also their tau-modes. We derive a formula for the polar angle distribution of the charged lepton in the (l nu) c.m. frame and compute the partial helicity rates that multiply the angular factors in the decay distribution. For t…
In this paper we study the semileptonic decays of the $B_c$ meson in the Light-Cone Sum Rule (LCSR) approach. The result for each channel depends on the corresponding distribution amplitude of the final meson. For the case of $B_c$ decaying into a pseudoscalar meson, to twist-3 accuracy only the leading twist distribution amplitude (DA) is involved if we start from a chiral current. If we choose a suitable chiral current in the vector meson case, the main twist-3 contributions are also eliminated and we can consider the leading twist contribution only. The leading twist distribution amplitudes…
We investigate the effect of intermediate charmed meson loops on the M1 radiative decays $J/ψ\to η_c γ$ and $ψ'\rightarrowη^{(\prime)}_cγ$ as well as the isospin violating hadronic decays $ψ'\rightarrow J/ψ\,π^0(η)$ using heavy hadron chiral perturbation theory (HH$χ$PT). The calculations include tree level as well as one loop diagrams and are compared to the latest data from CLEO and BES-III. Our fit constrains the couplings of 1S and 2S charmonium multiplets to charmed mesons, denoted $g_2$ and $g_2^\prime$, respectively. We find that there are two sets of solutions for $g_2$ and $g_2^\prime…
We investigate the masses of the pseudoscalar ($D$($D^0$, $D^+$), $\bar{D}$($\bar{D^0}$, $D^-$) and vector open charm mesons ($D^*$($D^{*0}$, $D^{*+}$), ${\bar{D}}^*$(${\bar{D}}^{*0}$, $D^{*-}$) as well as the pseudoscalar ($η_c(1S)$, $η_c(2S)$) and the vector charmonium states ($J/ψ$, $ψ(2S)$, $ψ(1D)$) in the asymmetric hot strange hadronic medium in the presence of strong magnetic fields. In the magnetized medium, the mass modification of open charm mesons due to their interactions with baryons and the scalar fields ($σ$, $ζ$, and $δ$) are investigated in a chiral effective model. Moreover, …
The semileptonic decays, $B_{c}{\longrightarrow}{χ_c}(h_c)+{\ell}+{ν}_{\ell}$, and the two-body nonleptonic decays, $B_{c}{\longrightarrow}{χ_c}(h_c)+h$, (here $χ_c$ and $h_c$ denote $(c\bar c[^3P_J])$ and $(c\bar c[^1P_1])$ respectively, and $h$ indicates a meson) were computed. All of the form factors appearing in the relevant weak-current matrix elements with $B_c$ as its initial state and a $P$-wave charmonium state as its final state for the decays were precisely formulated in terms of two independent overlapping-integrations of the wave-functions of $B_c$ and the $P$-wave charmonium and …
Symmetry analysis involving meson mixing for charmonium decay
本文基于 SU(3) 味对称性，利用群表示理论和 spurion 八重态确定粲偶素两体衰变的有效哈密顿量，引入合成 nonet 描述介子混合，并应用于分析矢量-赝标末态的强与电磁振幅相对相位。
Inspired by the recent measurement of the ratio of $B_c$ branching fractions to $J/ψπ^+$ and $J/ψμ^+ν_μ$ final states at the LHCb detector, we study the semileptonic decays of $B_c$ meson to the S-wave ground and radially excited 2S and 3S charmonium states with the perturbative QCD approach. After evaluating the form factors for the transitions $B_c\rightarrow P,V$, where $P$ and $V$ denote pseudoscalar and vector S-wave charmonia, respectively, we calculate the branching ratios for all these semileptonic decays. The theoretical uncertainty of hadronic input parameters are reduced by utilizin…
Inspired by the observation of charmonium-like state $X(3915)$, we explore the discovery potential of the $X(3915)$ production via meson photoproduction process. By investigating the $γp \to J/ψωp$ process including the $X(3915)$ signal and background contributions, we obtain the corresponding information of the cross section, the Dalitz plot and the $J/ψω$ invariant mass spectrum, which is helpful to further experimental study of $X(3915)$ via meson photoproduction.
We study the photon spectrum in the radiative decays of the charmonium $\frac{1}Γ\frac{dΓ(J/ψ\rightarrowγgg)}{dz}$ as an excellent scene for hunting the exotic mesons (hybrids $q\bar{q}g$ and glueballs $gg$) and an ideal frame for the theoretical and phenomenological investigations of the gluon nature in IR, by subtle estimation of its non-zero effective mass which seems required in Quark-Gluon Constituent Model (QGCM) for identifying the nature of these exotic species.
The quark potential model for mesons and its extension for hybrid mesons are used to study the effects of radial excitations on the masses, sizes and radial wave functions at the origin for conventional and hybrid charmonium mesons. These results can help in experimentally recognizing hybrid mesons. The properties of conventional and hybrid charmonium mesons are calculated for the ground and radially excited states using the shooting method to numerically solve the required Schrodinger equation for the radial wave functions. We compare our results with the experimentally observed masses and t…
Exotic and higher spin (> 1) mesons are still not throughly investigated in lattice QCD. Using a set of derivative based operators we report our exploratory study of these mesons in charmonium region. We use a 12^3 X 48 anisotropic (xi = 3) clover lattice with inverse temporal lattice spacing a^-1 = 6.05 GeV. Techniques developed in this exploratory study will be utilized in our future comprehensive study of light hybrid mesons that are to be explored in the 12 GeV GlueX experiment at Jefferson Laboratory.
We show that the factorization assumption in color-suppressed $B$ meson decays is not ruled out by experimental data on $B \ra K(K^*) + J/Ψ(Ψ^{'})$. The problem previously pointed out might be due to an inadequate choice of hadronic form factors. Within the Isgur-Wise SU(2) heavy flavor symmetry framework, we search for possible $q^2$ dependence of form factors that are capable of explaining simultaneously the large longitudinal polarization $ρ_L$ observed in $B \ra K^* + J/Ψ$ and the relatively small ratio of rates $R_{J/Ψ} = Γ(B \ra K^* + J/Ψ)/Γ(B \ra K + J/Ψ)$. We find out that the puzzle c…
扫码添加微信好友，提出您的宝贵建议 👇
💡 备注请填写：网站反馈
发表机构由 AI 从论文文本抽取，如发现错误，欢迎反馈修正建议。