arXiv subjects

U. Özdem

Publications and source records attributed to U. Özdem.

34 records · Page 2Linked to original sources

arXiv2024

Analysis of the $\mathrm{X_{AV}}$ state through its electromagnetic properties

To improve our understanding of the quark-gluon dynamics underlying multiquark states, we systematically study their electromagnetic properties. In this study, the magnetic and quadrupole moments of the theoretically predicted singly-charmed state with the quantum numbers $\mathrm{J^P = 1^+}$ is investigated within the framework of the QCD light-cone sum rules method by considering the diquark-antidiquark configuration of this state with quark contents $[ud][\bar{c}\bar{s}]$. The predicted results for the magnetic and quadrupole moments are as $μ_{\mathrm{X_{AV}}}=-0.89 ^{+0.14}_{-0.12}~μ_N $ and $\mathcal{D}_{\mathrm{X_{AV}}} = (-0.46 ^{+0.07}_{-0.06})\times 10^{-2} ~\mbox{fm}^2$. The results obtained can be useful in determining the exact nature of this state. This work will hopefully stimulate experimental interest in the study of the electromagnetic properties of multiquark systems.

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arXiv2024

Elucidating the nature of hidden-charm pentaquark states with spin-$\frac{3}{2}$ through their electromagnetic form factors

We perform a systematic study of the electromagnetic properties of exotic states to shed light on their nature, which is still controversial and not fully understood. The magnetic dipole and higher multipole moments of a hadronic state are as fundamental a dynamical quantity as its mass, and they contain valuable information about the deep structure underlying it. In the present work, we have explored the magnetic dipole and higher multipole moments of the hidden-charm pentaquarks with quantum number $J^P = 3/2^-$ using the QCD light-cone sum rule method and different interpolating currents. The obtained results show that different interpolating currents employed to probe pentaquarks with the same quark content produce varying results for their magnetic dipole and higher multipole moments at all. This can be interpreted to mean that there is more than one hidden-charm pentaquark with identical quark content but with different magnetic dipole and higher multipole moments. The nature, internal structure, and quark-gluon configurations of these states can be better understood by studying their electromagnetic properties.

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arXiv2024

Analysis of the $Z_b(10650)$ state based on electromagnetic properties

In this study, the magnetic and quadrupole moments of the $Z_b(10650)$ state are determined using the compact diquark-antidiquark interpolating current through the QCD light-cone sum rule. The values that are obtained as a result of the analysis are as follows: $μ_{Z_b} = 2.35^{+0.34}_{-0.33}~μ_N$ and $\mathcal{D}_{Z_b} =(1.82^{+0.35}_{-0.31})\times 10^{-2}~\mbox{fm}^2$. Examining the results obtained, it can be seen that the magnetic moments are large enough to be measured experimentally, while the quadrupole moment is obtained as a small but non-zero value, corresponding to a prolate charge distribution. The magnetic moment is the leading-order response of a bound system to a weak external magnetic field. It therefore provides an excellent platform to probe the internal structures of hadrons governed by the quark-gluon dynamics of QCD.

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arXiv2023

Magnetic dipole moments of the $Ω_{c}(3185)^0$ and $Ω_c(3327)^0$ states from molecular perspective

In this paper we study the magnetic dipole moments of the newly discovered $Ω_{c}(3185)^0$ and $Ω_c(3327)^0$, assuming that $Ω_{c}(3185)^0$ and $Ω_c(3327)^0$ are $S$-wave $D Ξ$ and $D^* Ξ$ molecular pentaquark states, respectively. Together with these states, the magnetic dipole moments of possible $D_s Ξ$, $D_s^* Ξ$, $D Ξ^*$, and $D_s Ξ^*$ pentaquark states are also studied. The magnetic dipole moments of these singly-charmed pentaquarks are estimated within the framework of the QCD light cone sum rules utilizing the photon distribution amplitudes. In the search for the properties of singly-charmed molecular pentaquark states, the results obtained for the magnetic dipole moments can be useful.

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arXiv2023

Magnetic and quadrupole moments of the $Z_{c}(4020)^+$, $Z_{c}(4050)^+$, and $Z_{c}(4600)^{+}$ states in the diquark-antidiquark picture

The magnetic and quadrupole moments of the $Z_{c}(4020)^+$, $Z_{c}(4050)^+$ and $Z_{c}(4600)^{+}$ states are calculated within the QCD light-cone sum rules. The compact diquark-antidiquark interpolating currents and the distribution amplitudes of the on-shell photon are used to extract the magnetic and quadrupole moments of these states. The magnetic moments are acquired as $μ_{Z_{c}} = 0.50 ^{+0.22}_{-0.22}~μ_N$, $μ_{Z^{1}_{c}}=1.22 ^{+0.34}_{-0.32}~μ_N$, and $μ_{Z^2_{c}}=2.40 ^{+0.53}_{-0.48}~μ_N$ for the $Z_{c}(4020)^+$, $Z_{c}(4050)^+$ and $Z_{c}(4600)^{+}$ states, respectively. The magnetic moments evaluated for the $Z_{c}4020)^+$, $Z_{c}(4050)^+$ and $Z_{c}(4600)^{+}$ states are sufficiently large to be experimentally measurable. The magnetic moment is an excellent platform for studying the internal structure of hadrons governed by the quark-gluon dynamics of QCD because it is the leading-order response of a bound system to a weak external magnetic field. The quadrupole moment results are $\mathcal{D}_{Z_c}=(0.20 ^{+0.05}_{-0.04}) \times 10^{-3}~\mbox{fm}^2 $, $\mathcal{D}_{Z_c^1}=(0.57 ^{+0.07}_{-0.08}) \times 10^{-3}~\mbox{fm}^2 $, and $\mathcal{D}_{Z_c^2}=(0.30 ^{+0.05}_{-0.04}) \times 10^{-3}~\mbox{fm}^2 $ for the $Z_{c}(4020)^+$, $Z_{c}(4050)^+$ and $Z_{c}(4600)^{+}$ states, respectively. We obtain a non-zero, but small, value for the quadrupole moments of the $Z_c$ states, which indicates a non-spherical charge distribution. The nature and internal structure of these states can be elucidated by comparing future experimental data on the magnetic and quadrupole moments of the $Z_{c}(4020)^+$, $Z_{c}(4050)^+$, and $Z_{c}(4600)^{+}$ states with the results of the present study.

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arXiv2023

Gravitational form factors of $Δ$ baryon via QCD sum rules

The gravitational form factors of a hadron are defined through the matrix elements of the energy-momentum tensor current, which can be decomposed into the quark and gluonic parts, between the hadronic states. These form factors provide important information for answering fundamental questions about the distribution of the energy, the spin, the pressure and the shear forces inside the hadrons. Theoretical and experimental studies of these form factors provide exciting insights on the inner structure and geometric shapes of hadrons. Inspired by this, the gravitational form factors of $Δ$ resonance are calculated by employing the QCD sum rule approach. The acquired gravitational form factors are used to calculate the composite gravitational form factors like the energy and angular momentum multipole form factors, D-terms related to the mechanical properties like the internal pressure and shear forces as well as the mass radius of the system. The predictions are compared with the existing results in the literature.

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arXiv2023

Electromagnetic properties of the $Σ_{c}(2800)^+$ and $Λ_c(2940)^+$ states via light-cone QCD

The $Σ_{c}(2800)^+$ and $Λ_c(2940)^+$ states are among the most interesting and intriguing particles whose internal structures have not yet been elucidated. Inspired by this, the magnetic dipole moments of the $Σ_{c}(2800)^+$ and $Λ_c(2940)^+$ states with quantum numbers $J^P = \frac{1}{2}^-$ and $J^P = \frac{3}{2}^-$, respectively, are analyzed in the framework of QCD light-cone sum rules, assuming that they have a molecule composed of a nucleon and a $D^{(*)}$ meson. The magnetic dipole moments are obtained as $μ_{Σ_c^{+}}=0.26 \pm 0.05~μ_N$ and $μ_{Λ_c^{+}}=-0.31 \pm 0.04~μ_N$. The magnetic dipole moment is the leading-order response of a bound system to a weak external magnetic field. It therefore offers an excellent platform to explore the inner organization of hadrons governed by the quark-gluon dynamics of QCD. Comparison of the findings of this analysis with future experimental results on the magnetic dipole moments of the $Σ_{c}(2800)^+$ and $Λ_c(2940)^+$ states may shed light on the nature and internal organization of these states. The electric quadrupole and magnetic octupole moments of the $Λ_c(2940)^+$ states have also been calculated, and these values are determined to be $\mathcal Q_{Λ_c^+} = (0.65 \pm 0.25) \times 10^{-3}$~fm$^2$ and $ \mathcal O_{Λ_c^+} = -(0.38 \pm 0.10) \times 10^{-3}$~fm$^3$, respectively. The values of the electric quadrupole and magnetic octupole moments show a non-spherical charge distribution. We hope that our estimates of the electromagnetic properties of the $Σ_{c}(2800)^+$ and $Λ_c(2940)^+$ states, together with the results of other theoretical studies of the spectroscopic parameters of these states, will be useful for their search in future experiments and will help us to define the exact internal structures of these states.

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arXiv2023

Electromagnetic properties of $\bar D^{()}Ξ^{\prime}_c$, $\bar D^{()}Λ_c$, $\bar D_s^{()}Λ_c$ and $\bar D_s^{()}Ξ_c$ pentaquarks

To elucidate the internal structure of exotic states is one of the central purposes of hadron physics. Motivated by this, we study the electromagnetic properties of $\bar D^{(*)}Ξ^{\prime}_c$, $\bar D^{(*)}Λ_c$, $\bar D_s^{(*)}Λ_c$ and $\bar D_s^{(*)}Ξ_c$ pentaquarks without strange, with strange and with double strange through QCD light-cone sum rules. We have also evaluated electric quadrupole and magnetic octupole moments of the $\bar D^{*}Ξ^{\prime}_c$, $\bar D^{*}Λ_c$, $\bar D_s^{*}Λ_c$ and $\bar D_s^{*}Ξ_c$ pentaquarks. The magnetic dipole moment is the leading-order response of a bound system to a soft external magnetic field. Thus, it ensures a prominent platform for the examination of the internal organizations of hadrons governed by the quark-gluon dynamics of QCD. We look forward to the present study stimulating the interest of experimentalists in investigating the electromagnetic properties of the hidden-charm pentaquarks.

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arXiv2023

Exploring the magnetic dipole moments of $T_{QQ \bar q \bar s}$ and $T_{QQ \bar s \bar s}$ states in the framework of QCD light-cone sum rules

Motivated by the recent observation of the tetraquark $ T_{cc}^{+}$, we investigate the magnetic dipole moments of the possible single and double strange partners, $T_{QQ \bar q \bar s}$ and $T_{QQ \bar s \bar s}$, with the spin-parity $ J^{P} = 1^{+}$ by means of the QCD light-cone sum rules. To this end, we model these states as diquark-antidiquark states with different organizations and interpolating currents. The results of magnetic dipole moments obtained using different diquark-antidiquark structures differ from each other, considerably. The magnetic dipole moment is the leading-order response of a bound system to a soft external magnetic field. Therefore, it provides an excellent platform for investigation of the inner structures of hadrons governed by the quark-gluon dynamics of QCD.

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arXiv2023

Gravitational transition form factors of $N \rightarrow Δ$ via QCD light-cone sum rules

We present the first direct calculation on the gravitational form factors (GFFs) of the $N \rightarrow Δ$ transition using an analytic method, the QCD light-cone sum rules. The matrix element of the quark part of the energy momentum tensor current sandwiched between the nucleon and $Δ$ states are parameterized in terms of five independent conserved and four independent non-conserved GFFs, for calculation of which we use the distribution amplitudes (DAs) of the on-shell nucleon expanded in terms of functions with different twists. We present the results for two sets of light-cone input parameters. The results indicate that the behavior of the form factors with respect to $Q^2$ are described by multipole fit functions. Our results may be checked by other phenomenological models including the Lattice QCD as well as future related experiments.

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arXiv2022

Magnetic moment of the $X_1(2900)$ state in the diquark-antidiquark picture

Motivated by the discovery of fully open-flavor tetraquark states $X_0(2900)$ and $X_1(2900)$ by the LHCb Collaboration, the magnetic dipole moment of the $X_1(2900)$ state with the quantum numbers $ J^{P} = 1^{-}$ is determined in the diquark-antidiquark picture using the light-cone sum rules. The numerical result is obtained as $ μ_{X_1}=0.79^{+0.36}_{-0.39}\,μ_N$. The magnetic moments of hadrons encompasses useful knowledge on the distributions of charge and magnetization their inside, which can be used to better understand their geometrical shapes and quark-gluon organizations. The observation of the $X_0(2900)$ and $X_1(2900)$ as the first two fully open-flavor multiquark states has opened a new window for investigation of the exotic states. The obtained results in the present study may shed light on the future experimental and theoretical searches on the properties of fully open-flavor multiquark states.

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arXiv2021

Magnetic dipole moments of the $T_{cc}^+$ and $Z_V^{++}$ tetraquark states

Inspired by the observation of the doubly charmed state $T_{cc}$ and following theoretical studies on its spectroscopic parameters, we investigate its magnetic dipole moment assigning it the quantum numbers $J^P=1^+$ and both the compact diquark-antidiquark and molecular structures in the framework of the light-cone QCD. We also calculate the magnetic dipole moment of the theoretically predicted singly charmed state, $Z_V^{++}$, with two units of electric charge and the quantum numbers $J^P=1^-$ in diquark-antidiquark picture. The numerical results are obtained as $μ_{T_{cc}^+-Di} =0.66^{+0.34}_{-0.23}~μ_N$, $ μ_{T_{cc}^+-Mol} =0.43^{+0.23}_{-0.22}~μ_N $ and $μ_{Z_{V}^{++}} =3.35^{+0.89}_{-0.73} ~μ_N$. These results may be checked via other phenomenological approaches. The obtained results may be useful in exact determinations of the natures of these states.

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arXiv2021

Magnetic dipole moment of the $Z_{cs}(3985)$ state: diquark-antidiquark and molecular pictures

We calculate the magnetic dipole moment of the newly observed charged hidden-charmed open strange $ Z_{cs}(3985)^- $ state, recently observed by BESIII Collaboration. Based on the information provided by the experiment and theoretical studies followed the observation, we assign the quantum numbers $ J^{P} = 1^{+}$ and the quark composition $ c \bar c s\bar u $ to this state and estimate the magnetic dipole moment of this resonance in both the compact diquark-antidiquark and molecular pictures. We apply the light cone QCD formalism and use the distribution amplitudes of the on-shell photon with different twists. The obtained results in both pictures are consistent with each other within the errors. The magnitude of the magnetic dipole moment shows that it is accessible in the experiment.

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arXiv2021

Gravitational form factors of $N(1535)$ in QCD

We calculate the gravitational form factors of the excited $N(1535)$ state with the quantum numbers $I(J^P)=\frac{1}{2}(\frac{1}{2}^-)$ via light cone QCD sum rules (LCSR). To this end, we consider the quark part of the energy-momentum tensor (EMT) current and use the general form of the nucleon's interpolating field as well as the distribution amplitudes (DAs) of $N(1535)$. As both the nucleon and $N(1535)$ couple to the same current, the $N(1535) \rightarrow N$ gravitational transition form factors are entered to the calculations as the main input parameters. First we revisit the transitional gravitational form factors of $N(1535) \rightarrow N$, then extract the values of the form factors of the $N(1535)$ excited state. We observe that the gravitational form factors of $N(1535)$ in terms of $Q^2$ are well described by the multipole fit function. As a byproduct, we also calculate the pressure and energy density at the center of $N(1535)$ and estimate its mechanical radius.

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arXiv2020

Gravitational form factors of hyperons in light-cone QCD

The quark parts of the gravitational form factors of hyperons are calculated by means of the light-cone QCD sum rule. In the calculations, the distribution amplitudes (DAs) of $Σ$, $Ξ$ and $Λ$ together with the general forms of their interpolating currents as well as the quark part of the energy-momentum tensor current are used. These form factors can provide information on their mass and distributions of the angular momentum, energy and pressure inside the hyperons. It is obtained that the $Q^2$ dependencies of the hyperon gravitational form factors are nicely characterized by a multipole fit function. Using the fits of these form factors, some mechanical properties such as the mechanical radius of the hyperons and the pressure and energy distributions at the center of these particles are obtained. The obtained results can help us in better understanding of the internal structures of these baryons and the QCD as theory of the strong interaction.

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arXiv2020

Gravitational transition form factors of $N(1535) \rightarrow N$

We employ the quark part of the symmetric energy-momentum tensor current to calculate the transition gravitational form factors of the $N(1535) \rightarrow N$ by means of the light cone QCD sum rule formalism. In numerical analysis, we use two different sets of the shape parameters in the distribution amplitudes of the $ N(1535) $ baryon and the general form of the nucleon's interpolating current. It is seen that the momentum squared dependence of the gravitational form factors can be well described by the p-pole fit function. The results obtained by using two sets of parameters are found to be quite different from each other and the $N(1535) \rightarrow N$ transition gravitational form factors depend highly on the shape parameters of the distribution amplitudes of the $N(1535)$ state that parametrize relative orbital angular momentum of the constituent quarks.

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