Using the same quenched limit as input, we compare charmonium spectra predicted by two different models, i.e., coupled-channel model and screened potential in mass region below 4 GeV, which contributions from decay channels involving $P$-wave (as well even higher excited) $D$ mesons can be neglected. We find that models have similar global features describing spectrum since they approximately embody effect of vacuum polarization dynamical light quark pairs. Adopting these will helpful to...

We present a complete evaluation for the prompt η_{c} production at LHC next-to-leading order in α_{s} nonrelativistic QCD. By assuming heavy-quark spin symmetry, recently observed data by LHCb results very strong constraint on upper bound of color-octet long-distance matrix element ⟨O^{J/ψ}(^{1}S_{0}^{[8]})⟩ J/ψ. find this is consistent with our previous study J/ψ yield and polarization can give good descriptions measurements, but inconsistent some other theoretical estimates. This may...

We give predictions of J/ψ and ψ(2S) yields polarizations in prompt production at hadron colliders based on non-relativistic QCD factorization formula. calculate short-distance coefficients all important color-octet intermediate channels as well color-singlet up to $$ \mathcal{O}\left({\alpha}_S^4\right) , i.e. next-to-leading order α S . For production, we also take into account feeddown contributions from χ cJ (J=0,1,2) decays. Color-singlet long-distance matrix elements (LDMEs) are...

We reexamine the rescattering mechanism for X(3872), as a candidate 2P charmonium state ${\ensuremath{\chi}}_{c1}(2\mathrm{P})$, decaying to $J/\ensuremath{\psi}\ensuremath{\rho}(\ensuremath{\omega})$ through exchanging ${D}^{(*)}$ mesons between intermediate states $D(\overline{D})$ and ${\overline{D}}^{*}({D}^{*})$. evaluate dispersive part, well absorptive one, of amplitude find that contribution from part is dominant even when X(3872) lies above threshold neutral channel...

$\Upsilon(nS)$ and $\chi_b(nP)$ (n=1,2,3) production at the LHC is studied next-to-leading order in $\alpha_s$ nonrelativistic QCD. Feeddown contributions from higher $\chi_b$ $\Upsilon$ states are all considered for lower cross sections polarizations. The long distance matrix elements (LDMEs) extracted yield data, then used to make predictions polarizations, which found be consistent with measured polarization data within errors. In particular, $\Upsilon(3S)$ puzzle can understood by a...

In order to explain the observed unusually large dipion transition rates of $\ensuremath{\Upsilon}(10870)$, scalar resonance contributions in rescattering model transitions $\ensuremath{\Upsilon}(4S)$ and $\ensuremath{\Upsilon}(5S)$ are studied. Since imaginary part amplitude is expected be dominant, ratios which identified with $\ensuremath{\Upsilon}(5S)$, that can understood as mainly coming from difference between $p$ values their decays into open bottom channels, estimated numerically...

An analysis including most recent Belle data on X(3872) is performed, using coupled channel Flatté formula. A third sheet pole close to but \textit{below} $D^0D^{*0}$ threshold found, besides the bound state/virtual state discussed in previous literature. The co-existence of two poles near indicates that may be ordinary $c\bar c$ $2 ^3P_1$ origin, distorted by strong effects. latter manifests itself as a molecular (or virtual state).

We study the property of $X(3872)$ meson by analyzing $B\to K D\bar D^*$ and J/\psi \pi^+\pi^-$ decay processes. The competition between rescattering mediated through a Breit-Wigner resonance generated from local $D\bar{D}^* \to D\bar{D}^*$ interaction is carefully studied an effective lagrangian approach. Three different fits are performed: pure case, $D\bar{D}^*$ molecule case with only vertices (generated loop chain), mixed case. It found that data supports picture where X(3872) mainly...

Abstract Recently, the LHCb experimental group found an exotic state from process. A key question is whether it just a molecule or may have confined tetraquark ingredient. To investigate this, different methods were used, including two-channel ( and ) K -matrix unitarization single-channel Flatté-like parametrization method analyzed utilizing pole counting rule spectral density function sum rule. These analyses demonstrated that molecular state, although possibility there exist elementary...

$B\to\chi_{c1}(1P,2P)K$ decays are studied in QCD factorization by treating charmonia as nonrelativistic bound states. No infrared divergences exist the vertex corrections, while logarithmic end-point singularities hard spectator corrections can be regularized a momentum cutoff. With certain uncertainties we find that $B\to\chi_{c1}(2P)K$ decay rate comparable to $B\to\chi_{c1}(1P)K$, and get $Br(B^0 \to \chi_{c1}' K^0) =Br(B^+ K^+)\approx 2\times 10^{-4}$. This might imply possible...

We evaluate the production cross sections of $X(3872)$ at LHC and Tevatron NLO in ${\ensuremath{\alpha}}_{s}$ NRQCD by assuming that short-distance proceeds dominantly through its ${\ensuremath{\chi}}_{c1}^{\ensuremath{'}}$ component our ${\ensuremath{\chi}}_{c1}^{\ensuremath{'}}\ensuremath{-}{D}^{0}{\overline{D}}^{*0}$ mixing model for $X(3872)$. The outcomes fits to CMS ${p}_{T}$ distribution can well account recent ATLAS data a much larger range transverse momenta ($10\text{ }\text{...

Abstract A near-threshold enhancement in the $$D^{+}_{s}D^{-}_{s}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>D</mml:mi><mml:mi>s</mml:mi><mml:mo>+</mml:mo></mml:msubsup><mml:msubsup><mml:mi>D</mml:mi><mml:mi>s</mml:mi><mml:mo>-</mml:mo></mml:msubsup></mml:mrow></mml:math> system, dubbed as X (3960), is observed by LHCb collaboration recently. combined analysis on $$\chi _{c0}(3930)~(\rightarrow D^+ D^-)$$...

We study the energy distributions of dipion transitions $\ensuremath{\Upsilon}(5S)$ to $\ensuremath{\Upsilon}(1S,2S,3S){\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ in final-state rescattering model. Since is well above open bottom thresholds, are expected mainly proceed through real processes $\ensuremath{\Upsilon}(5S)\ensuremath{\rightarrow}{B}^{(*)}{\overline{B}}^{(*)}$ and...

A bstract We calculate the NLO corrections for gluon fragmentation functions to a heavy quark-antiquark pair in 1 S 0 [1] or [8] state within NRQCD factorization. use integration-by-parts reduction reduce original expression simpler master integrals (MIs), and then set up differential equations these MIs. After calculating boundary conditions, MIs can be obtained by solving numerically. Our results are expressed terms of asymptotic expansions at singular points z (light-cone momentum...

A bstract We study the mass spectra of $$ \overline{Q}Q\overline{Q}Q <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mover> <mml:mi>Q</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> ( Q = c, b ) systems in QCD sum rules with complete next-to-leading order (NLO) contribution to perturbative part correlation functions. Instead meson-meson or diquark-antidiquark currents, we use diagonalized currents under operator renormalization. find that differing from conventional...

The $\ensuremath{\eta}$ transitions of $\ensuremath{\Upsilon}(4S,5S)$ into $\ensuremath{\Upsilon}(1S,2S)$ are studied in the rescattering model by considering final state interactions above $B\overline{B}$ threshold. width transition $\ensuremath{\Upsilon}(4S)$ $\ensuremath{\Upsilon}(1S)$ is found to be larger than that dipion transition, and ratio $\ensuremath{\Gamma}(\ensuremath{\Upsilon}(4S)\ensuremath{\rightarrow}\ensuremath{\Upsilon}(1S)\ensuremath{\eta})$...

With the QCD sum rules approach, we study newly discovered doubly heavy baryon $\Xi_{cc}^{++}$. We analytically calculate next-to-leading order (NLO) contribution to perturbative part of $J^{P} = \frac{1}{2}^{+}$ current with two identical quarks, and then reanalyze mass $\Xi_{cc}^{++}$ at NLO level. find that correction significantly improves both scheme dependence scale dependence, whereas it is hard control these theoretical uncertainties leading order. contribution, estimated be...

In the framework of QCD factorization, we study B-meson exclusive decays $\stackrel{\ensuremath{\rightarrow}}{B}{\ensuremath{\chi}}_{\mathrm{cJ}}K$ where spin-triplet P-wave charmonium states ${\ensuremath{\chi}}_{\mathrm{cJ}}(J=0,1,2)$ are described by color-singlet nonrelativistic wave functions. We find that for these (except ${\ensuremath{\chi}}_{c1})$ there infrared divergences arising from nonfactorizable vertex corrections as well logarithmic end-point singularities spectator...

We give predictions of $\jpsi$ and $\psits$ yields polarizations in prompt production at hadron colliders based on non-relativistic QCD factorization formula. calculate short-distance coefficients all important color-octet intermediate channels as well color-singlet up to $\mathcal{O}(α_S^4)$, i.e. next-to-leading order $α_S$. For production, we also take into account feeddown contributions from $χ_{cJ}$(J=0,1,2) decays. Color-singlet long-distance matrix elements (LDMEs) are estimated by...

A bstract The next-to-leading order (NLO) ( $$ \mathcal{O} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>O</mml:mi></mml:math> {\alpha}_s^3 xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msubsup><mml:mi>α</mml:mi><mml:mi>s</mml:mi><mml:mn>3</mml:mn></mml:msubsup></mml:math> )) corrections for gluon fragmentation functions to a heavy quark-antiquark pair in 3 {P}_J^{\left[1,8\right]}...

A bstract We study the mass spectra of hidden-charm tetraquark systems with quantum numbers ( I G ) J P = (1 + )1 (and their $$ \frac{1}{2} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mfrac> <mml:mn>1</mml:mn> <mml:mn>2</mml:mn> </mml:mfrac> </mml:math> partners) using QCD sum rules. The analysis incorporates complete next-to-leading order (NLO) contribution to perturbative part operator product expansions, particular attention mixing effects due renormalization group...

The semi-inclusive $B$-meson decay into spin-singlet $D$-wave ${2}^{\ensuremath{-}+}$ charmonium, $B\ensuremath{\rightarrow}{\ensuremath{\eta}}_{c2}+X$, is studied in nonrelativistic QCD. Both color-singlet and color-octet contributions are calculated at next-to-leading order the strong coupling constant ${\ensuremath{\alpha}}_{s}$. nonperturbative long-distance matrix elements evaluated using operator evolution equations. It found that $^{1}D_{2}$ contribution tiny, while channels make...