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J. Y. Süngü

Publications and source records attributed to J. Y. Süngü.

15 recordsLinked to original sources

Hot and dense medium effects on the $B_s^*$ and $B^*$ multiplets

We present an extensive analysis of the in-medium masses and decay constants of the $B_s^*(5415)$ and $B^*(5325)$ multiplets, including both particles and antiparticles, using QCD sum rules at finite temperature and density. The OPE incorporates the full temperature- and density-dependent contributions from the quark, gluon, and mixed condensates. Computing the strange ($B_s^{*0}$, $\bar{B}_s^{*0}$), charged ($B^{*\pm}$), and neutral ($B^{*0}$, $\bar{B}^{*0}$) doublet properties allows us to study the effects of flavor symmetry breaking, strangeness, and heavy-quark decoupling on the beauty vector mesons in the medium. Our results indicate that the mass is remarkably resistant to the medium across the entire multiplet: no state loses more than $\sim 13\%$ of its vacuum value, even at $T = T_c$ and $n = 5n_0$, the extreme conditions explored here. The decay constant is far more sensitive, losing up to $\sim 78\%$ at the same point. Baryon density clearly dominates the medium response, while temperature plays a secondary role until the system approaches the deconfinement crossover. At zero density, every state loses almost the same fraction of its mass and decay constant: mass shifts lie between $-(0.5$-$1.1)\%$ and decay-constant shifts between $-(3.9$-$5.3)\%$, regardless of charge or flavor, so temperature alone does not distinguish a particle from its antiparticle. At finite baryon density, a clear particle-antiparticle asymmetry emerges: at $T = 0$ and $n = 5n_0$, the $\bar{B}^{*0}$ mass decreases by $12.9\%$, whereas the $B^{*0}$ mass shifts by only $6.1\%$, a gap of nearly seven percentage points driven entirely by the vector self-energy. This provides a theoretical basis for the future heavy-ion collision program at RHIC, LHC, FAIR, and NICA.

hep-ph↗

Temperature Effects on a Vector Hidden-Charm Molecule

We investigate the thermal properties of the $Y(4500)$ state within the framework of thermal QCD sum rules, assuming a $D_s \bar{D}_{s1}$ molecular configuration with $J^{PC}=1^{--}$. The analysis is performed at both zero and finite temperatures, employing the operator product expansion up to dimension-5 condensates. The Borel window and continuum threshold are carefully selected to ensure OPE convergence and pole dominance. As the temperature approaches the deconfinement temperature $T_c$, the $Y(4500)$ undergoes significant medium modifications: its mass decreases by $29\%$ and its decay constant is suppressed by $94\%$ relative to their vacuum values, while the decay width increases by $35\%$, signaling the dissociation of the state in the medium. These results indicate that the $Y(4500)$ becomes unstable near $T_c \approx 155~\mathrm{MeV}$, consistent with its melting into the quark-gluon plasma. The obtained thermal spectral parameters may serve as signatures for identifying the $Y(4500)$ in heavy-ion experiments at RHIC and LHC, and provide predictions for sequential suppression patterns in the exotic hadron sector.

hep-ph↗

Spectroscopic Properties of the Molecular $T_{cc}^{+}$ Meson in a Thermal Medium

In this work, we investigate the exotic doubly charmed molecular state $T_{cc}^{+}(3875)$ with quantum numbers $J^{P} = 1^{+}$ using the Thermal QCD Sum Rules framework. Employing a molecular interpolating current, we evaluate the two-point correlation function by incorporating non-perturbative condensate contributions up to dimension six. From the resulting thermal sum rules, we determine the temperature dependence of the mass, decay constant, and width of the $T_{cc}^{+}$ state. Our numerical analysis reveals that all quantities remain remarkably stable under temperature variations up to $T \simeq 120~\text{MeV}$, after which they change significantly. At the deconfinement temperature, the mass decreases to approximately $28\%$ of its vacuum value, and the decay constant drops to about $25\%$. We analyze the thermal evolution of the decay width of $T_{cc}^{+}$, finding $Γ_{T_{cc}^{+}}(0) = 434.95 \pm 7.66~\text{keV}$ at zero temperature. The width of $T_{cc}^{+}$ remains unchanged until $ T\simeq 120~\text{MeV}$, after which it begins to grow rapidly. The investigation of thermal effects on $T_{cc}^{+}$ provides new insights into QCD phase transitions, chiral symmetry restoration, and the properties of strongly interacting, hot, and dense matter. These findings are expected to serve as useful input for future experimental searches and phenomenological studies of exotic mesons.

hep-ph↗

An interpretation of the fully-charmed scalar state $X(6200)$ as a molecular di-meson

The LHCb Collaboration recently observed new structures in the invariant mass spectrum of $J/ψJ/ψ$ meson pairs produced in proton-proton collisions, including a narrow peak around $6.2$ GeV. This study investigates the thermal behavior of this newly discovered fully-charm resonance, assuming it to be an $η_cη_c$ molecule with quantum numbers $J^{PC} = 0^{++}$. Employing thermal QCD sum rules up to dimension four, we analyze the temperature dependence of the mass and the decay constant. Our results indicate that both physical quantities decrease as the temperature rises. Notably, at zero temperature, the mass and decay constant of the state are consistent with those reported in the existing literature. These findings are expected to provide valuable insights for future experimental investigations in this field.

hep-ph↗

Scalar fully-charm and bottom tetraquarks under extreme temperatures

Temperature dependences of masses and current couplings of the ground state of the fully heavy tetraquarks $T_{4c}$ and $T_{4b}$, composed of charm $(c)$ and bottom $(b)$ quarks and antiquarks with spin-parities $J^{PC} = 0^{++}$ are evaluated in the diquark antidiquark picture using Thermal QCD Sum Rules including vacuum condensates up to dimension four. The calculated values for $cc\bar{c}\bar{c}$ and $bb\bar{b}\bar{b}$ tetraquark states at $T=0$ align well with the experimental data on the broad structures. Based on the numerical analyses around the critical temperature, the mass of the $T_{4c}$ state decreases by $8\%$ compared to its vacuum state, while for its b partner, this percentage is approximately $3.3\%$. For the decay constants, the reductions are approximately $71\%$ and $66.6\%$, respectively. The precise exploration of tetraquark states awaits future scrutiny in upcoming experiments, including Belle II, Super-B, PANDA, and LHCb.

hep-ph↗

Nuclear medium effects on the properties of $Λ(1405)$

We study the $Λ(1405)$ resonance with $I(J^{P})=0(1/2^{-}) $ in the context of the pentaquark hypothesis in the nuclear medium. For the investigation of the influence of the nuclear medium on the physical parameters of $Λ(1405)$, we propose a molecular-type structure involving $K^{-}p$ and $\bar{K}^{0}n$ admixtures, correlated with the nuclear matter density. Our analysis reveals a substantial shift in both mass and residue, approximately $20\%$ and $38\%$, respectively. These findings have significant implications for experimental researchers aimed at identifying in-medium characteristics of hyperon resonances.

nucl-th↗

Dissociation of Pseudotensor Mesons through Critical Temperature

We have computed the masses and decay constants of isotriplet $π_2(1670)$, the isoscalar $η_2(1645)$ and $η_2(1870)$ states as the ground-state nonet of $1^1D_2$ case within the Thermal QCD sum rules framework. This method is applied to the spectral changes of pseudotensor mesons at high temperatures including quark, gluon, and mixed condensates up to the five dimensions. We found that their masses and decay constants are insensitive to temperature in low-temperature regions. At the near-critical temperature, we observed an exponential decrease of the masses of $π_2$, $η_2(1645)$, and $η_2(1870)$, but while the decay constant of $π_2$ is fallen, that of $η_2(1645)$ and $η_2(1870)$ is increased as a function of temperature. The modification of condensates at $T\neq 0$ is crucial to the change of considered mesons properties in a hot medium. We discuss and interpret the implications of the physical meaning of our results.

hep-ph↗

Impact of a thermal medium on newly observed $Z_{cs}(3985)$ resonance and its $ b $-partner

Motivated by the very recent discovery of the strange hidden-charm exotic state $Z_{cs}(3985)$ by the BESIII Collaboration, we study possible interpretation of this exotic state both at $ T= 0 $ and $ T\neq 0 $. We analytically compute the mass and meson-current coupling constant of this resonance with spin-parity $ J^{PC} = 1^{+-}$ at finite temperature approximation up to sixth order of the thermal operator dimension including non-perturbative contributions. Extracting thermal mass and meson-current coupling constant sum rules, the modifications on properties of $Z_{cs}(3985)$ state in hot medium is determined. As a by product, the hadronic parameters of the bottom partner of $Z_{cs}(3985)$ is estimated as well. Moreover the search of temperature effects on the hadronic parameters of hidden-charm meson $Z_{cs}(3985)$ and the bottom partner make us understand the phase transitions, chiral symmetry breaking and the properties of hot-dense matter in QCD.

hep-ph↗

Newly observed resonance $ X(4685) $: diquark-antidiquark picture

In this work, the mass and pole residue of $ X(4685) $ state with spin-parity $J^P=1^+$ are computed by the QCD sum rule approaches up to operator dimension seven based on the diquark-antidiquark configuration. For its mass we get $ m_{X_{cs}}= 4607^{+36}_{-22} $ MeV and pole residue $ λ_{X_{cs}}= 6.19^{+0.32}_{-0.24}\times 10^{-2}~\mathrm{GeV^5}$, which may be checked via other nonperturbative approaches as well as future experiments. As a by product, the mass of the hidden-bottom partner state of the $ X(4685) $ is extracted to be both around $ m_{X_{bs}}= (10604-10924) $ MeV and $ λ_{X_{bs}}= (42.2-53.7)\times 10^{-2}~\mathrm{GeV^5}$, which can be searched in the $Υϕ$ invariant mass distribution.

hep-ph↗

Modifications on the Properties of $D^*_{s0}(2317)$ as Four-quark State in Thermal Medium

Since the low mass of $D^*_{s0}(2317)$ has still been a problem to the conventional quark model, one can consider other options regarding as multi-quark system. Therefore we investigate the scalar open-charm state $D^*_{s0}(2317)$ by Thermal QCD Sum Rules (TQCDSR) method using the two-point correlation function together with contributions of the non-perturbative condensates up to dimension six. Deriving and numerically analyzing thermal mass and pole residue sum rules, we accomplish the effects on the properties of $D^*_{s0}(2317)$ resonance in hot medium. Our numerical evaluations indicate that the variations in mass and pole residue values are stable through the growing temperature up to $T\cong100~\mathrm{MeV}$, but they begin to fall after this point. At critical temperature, the values of mass and pole residue change up to $91\%, 70\% $ of their values in vacuum in the molecular scenario and $ 91\%, 69\% $ in the diquark-antidiquark scenario. Our results does not give any definite information as to whether $D^*_{s0}(2317)$ resonance has molecular or diquark-antidiquark structure since they are very close to each other to differentiate them. Besides, we predict the hadronic parameters of the bottom partner of the $D^*_{s0}(2317)$ resonance in both molecular and diquark-antidiquark pictures. This bound state is worth investigating in future experiments. Also the detailed search of hot medium effects on the hadronic parameters of open-charm meson $D^*_{s0}(2317)$ and the bottom partner could have some implications to define the QCD phase diagram obtained from heavy-ion collision experiments. Moreover these results can be useful in distinguishing conventional quark model mesons from exotica.

hep-ph↗

Missing Member of the $J^{PC} = 2^{--}$ Nonet in Extreme Conditions

The isoscalar member of the axial-tensor family that should take place in the further states of the PDG is still absent. In this study, analyzes are made as to whether one of the X states whose quantum numbers are unknown in this group, is a candidate for the missing resonance under the assignment $ 2^3D_2 $. Moreover, replacing the time evolution operator with the thermal average one, we construct the modified correlator satisfying Thermal QCD sum rules approach. We determine that the hadronic parameters of the considered nonet member are sensitive to the increment of temperature. This knowledge can be helpful to complete the $J^{PC} = 2^{--}$ light meson nonet and also explore the hot medium behaviors at upcoming heavy-ion collision experiments.

hep-ph↗

Axial-tensor Meson Family at $T\neq0$

The mass and decay constant of the axial-tensor meson nonets $ρ_2,~ω_2$ and a missing member and also their first excited states are analyzed by the Thermal QCD sum rules model including QCD condensates up to dimension five. Mass and decay constant values in terms of variations of temperature are very well stable from $T=0$ up to ~$T \cong 120 ~\mathrm{MeV}$. However nearly after these threshold, our numerical analysis indicate that they begin to diminish with increasing temperature. Mass value of these mesons and their first excited states decrease about $(1-13\%)$ compared to vacuum values and $(10-26\%)$ for the decay constants according to PDG data and $(9-26\%)$ and $(2-34\%)$ respectively concerning Regge Trajectory Model in the corresponding Thermal QCD sum rules calculations. The experimental results are already copious, but expected to grow up at ongoing and future heavy-ion experimental programs allowing us to compare our results.

hep-ph↗

In the Pursuit of $X(5568)$ and its Charmed Partner

The recent observation by the D$Ø$ collaboration of the first tetraquark candidate with four different quark flavors $(u, d, s$ and $ b)$ in the $B^0_sπ^{\pm}$ channel having a narrow structure, has still not been confirmed by other collaborations. Further independent experiments are required either to confirm the $X(5568)$ state or to set limits on its production. Though quantum numbers are not exactly clear, the results existing in the literature indicate that it is probably an axial-vector or scalar state candidate. In this study, mass and pole residue of the $X(5568)$ resonance assuming as a tightly bound diquark, with spin-parity both $J^{P}=1^{+}$ or $J^{PC}=0^{++}$ are calculated using two-point Thermal SVZ sum rules technique by including condensates up to dimension six. Moreover, its partner in the charm sector is also discussed. Investigations defining the thermal properties of $X(5568)$ and its charmed partner may provide valuable hints and information for the upcoming experiments such as CMS, LHCb and PANDA.

hep-ph↗

Probing Axial-Vector Charmonia $χ_{c1}(1P)$ and $χ_{c1}(2P)$

We investigate the ground-state heavy quarkonium $χ_{c1}(1P)$ and its first excited state $χ_{c1}(2P)$ with quantum numbers $J^{PC}=1^{++}$. The masses and decay constants of these charmonium states are computed using two-point QCD sum rule method by including quark, gluon and mixed condensates up to dimension-8. We compare our numerical results with the available experimental data as well as existing theoretical predictions in the literature.

hep-ph↗

Hidden-Beauty Broad Resonance $Y_b(10890)$ in Thermal QCD

In this work, the mass and pole residue of resonance $Y_b$ is studied by using QCD sum rules approach at finite temperature. Resonance $Y_b$ is described by a diquark-antidiquark tetraquark current, and contributions to operator product expansion are calculated by including QCD condensates up to dimension six. Temperature dependences of the mass $m_{Y_b}$ and the pole residue $λ_{Y_b}$ are investigated. It is seen that near a critical temperature $(T_c\simeq190~\mathrm{MeV})$, the values of $m_{Y_b}$ and $λ_{Y_b}$ are decreased to $87\%$, and to $44\%$ of their values at vacuum.

hep-ph↗