The production of mesons in proton-deuteron fusion has historically received considerable interest as a natural way to study the interaction between mesons and nuclear matter through final state interactions. Thus, the near threshold regions for the production of $\eta$ and $\pi^0$ mesons in $\text{p}\text{d} \rightarrow {}^3\text{He}X$ are already well explored, yet still subject of active...
We analyze here the mass spectrum of light vector and scalar mesons applying the novel approach developed in [1], where a modified soft wall model that includes a UV-cutoff at a finite z-position in the AdS space is used, thus introducing an extra energy scale. For this model, we found that the masses for the scalar and vector spectra are well fitted within $\delta_\text{RMS}=6.88\%$ for these...
Symmetry and symmetry breaking play significant roles in physics. In this contribution, we will discuss our recent progress on the emergent symmetry in dense nuclear matter which are hidden in the matter-free space. This discussion sheds light on the mechanisms of chiral symmetry breaking, scale symmetry breaking and also the flavor symmetry breaking.
Compton scattering off the proton in the third resonance region is analyzed , owing to the full combined analysis of pion- and photo-induced reactions in a coupled-channel effective Lagrangian model with K-matrix approximation. Two isospin I=3/2 resonances D33(1700) and F35(1930) are found to be essential in the range of 1.6 - 1.8 GeV. The recent beam asymmetry data of Compton scattering from...
Using the chiral unitary approach, combining with the heavy quark spin symmetry, we investigate the interactions of $J/\psi N$ with its coupled channels and look for the dynamical resonances in the interactions. One of the two $P_c$ states, $P_c (4450)$, found by LHCb experiments, is explained as a $\bar{D}^* \Sigma_c$ bound state in our theoretical model. To understand the properties of this...
$\eta$ and $\eta^\prime$ transition form factors and Padé approximants
We calculate two- and three-body decays of the (lightest) vector glueball into (pseudo)scalar,
(axial-)vector, as well as pseudovector and excited vector mesons in the framework of a model of
QCD. While absolute values of widths cannot be predicted because the corresponding coupling
constants are unknown, some interesting branching ratios can be evaluated by setting the mass of
the yet...
Counting hadronic states and QCD thermodynamics in a finite box are intimately
related. At small temperatures hadronic states are expected to saturate the partition
function, so, accepting the Particle Data Group (PDG) table [1] as the reference for
hadronic states, all the states listed by the PDG should also be counted as genuine
contributions to the QCD partition function and, hence,...
Hadrons composed of heavy quarks are the simplest ones to study in QCD.
They provide an affordable theoretical laboratory for investigating
the dynamics of gluons, mainly because quarks move slowly with respect
to each other as the sources of gluons and in the analysis of heavy meson
states one can safely take advantage of asymptotic freedom and expand
renormalized interactions in powers of...
We investigate (π0, η, η0) → γ∗γ transition form factors (TFFs) for both
space- and timelike regions using the light-front quark model. For the low
energy regime, we compare our LFQM results of the TFFs for low timelike
momentum transfer region and the slope parameters at q2 = 0 with the
recent experimental data from the Dalize decays of (π0, η, η0). For the high
energy regime, we show the...
The eta→3pi decays are a valuable source of information on low energy QCD. We present our updated results
for the extraction of the three flavor chiral symmetry breaking order parameters from these processes.
We use a Bayesian approach in the framework of resummed chiral perturbation theory to extract
information on the quark condensate and pseudoscalar decay constant in the chiral limit, as...
Following the discovery of the X(3872), several exotic states, collectively known as XYZ states, have recently been identified in the energy region of charmonium. Searches with proton-antiproton collisions, such as the upcoming PANDA experiment at FAIR, will play an essential role in the effort to shed light on the nature of these states, since the direct production mechanisms and high rates...
In binary neutron star mergers the dynamical backcoupling of the electroweak interaction to the neutron matter is relevant. To desribe this, a coupled non-perturbative treatment of both sectors is necessary. Functional methods, like Bethe-Salpeter-Equations and the Functional-Renormalization-Group can be used for this purpose. Since the dominant process is beta-decay, a first necessary step is...
We study thermal properties of a large-$N$ massless pion gas via a low-energy QCD approach given by an $O(N + 1)/O(N)$ nonlinear sigma model. In order to attain this, we build diagrammatically the associated free energy to $O(TM^{3})$ in the pion mass expansion through an effective vertex; we consider this since all its contributions coming from closed diagrams are to be taken into account. At...
The time projection chamber(HypTPC) has been developed for the H-dibaryon search experiment via (K-,K+) reactions at J-PARC. The high rate secondary beam up to 10^6 Hz from the world highest intensity proton beam should be taken into account. The HypTPC has the octagonal drift volume defined by the field cage, the cathode plane at the top and the amplification region at the bottom. The drift...
We use the Quark-Gluon String Model to obtain a quantitatively good description of the phi-meson production
experimental data in hadron-nucleon collisions on the spectra of secondary phi, as well as on the ratios of
phi/pi- and phi/K- production cross sections, for a wide energy region. We also consider the experimental
data on phi-meson production on nuclear targets, and we find that they...
The observation of the hidden-charm pentaquarks by the LHCb collaboration indicates an existence of exotic hadrons close to hidden-charm meson-baryon thresholds. In the literature, various model calculations have been performed such as the hadronic molecules and the compact multi-quark states. The observed states appear below the thresholds, and it indicates that the states are a loosely...
We investigate the two-flavor version of the extended linear sigma model (eLSM), which contains, besides the standard scalar and pseudoscalar quark-antiquark degrees of freedom, also vector and axial-vector mesons, as well as the nucleon and its chiral partner. We extend this model by an additional light scalar meson, a potential four-quark state, and the scalar glueball. We investigate...
The consistent simultaneous interpretation of pions and kaons both as bound states of quark and antiquark and as the (almost) massless boson states related, according to Goldstone’s theorem, to the dynamical (and explicit) breakdown of the chiral symmetries of QCD still represents a major challenge. Applying inversion to sufficiently simplified versions of the homogeneous Bethe–Salpeter...
We study isospin-breaking effects in the extended linear sigma model (eLSM) for $N_f=3$ quark flavors. The eLSM contains scalar, pseudoscalar, vector, and axial-vector mesons, which consist of quarks and antiquarks. It is constructed on the basis of a global chiral $U(N_f)_L \times U(N_f)_R$ symmetry which is spontaneously broken by a quark-antiquark condensate, as well as explicitly broken by...
The spectra of charged and neutral rho and pi-mesons in uniform homogeneous magnetic field (MF) are discussed in the framework of the path integral formalism and vacuum correlator method. The spectra of all 12 spin-isospin s-wave meson states were obtained analytically using the Hamiltonian for quarks with confinement potential in strong magnetic field. The states have 3 different types of...
The extended Linear Sigma Model (eLSM) is an effective hadronic model based on the linear realization of chiral symmetry
$U(N_f)_L \times U(N_f)_R$, with (pseudo-)scalar and (axial-)vector mesons as degrees of freedom. We study the
low-energy limit of the eLSM for $N_f=3$ by integrating out all fields except for the (pseudo-)Nambu-Goldstone bosons of
chiral symmetry breaking. After keeping...
In the potential model frame work, we study the S-wave molecular like structure of the di-baronic systems which consist baryon-baryon or baryon-antibaryon as a constituents. The mass spectra of the $\Sigma_{c}-\Sigma_{c}$ and $\Sigma_{c}-\overline{\Sigma_{c}}$ are predicted. By taking the deuteron as an approximation for our model calculation, the S-wave mass spectra of the molecular...
The electric ($\alpha_{\text{E1}}$) and magnetic ($\beta_{\text{M1}}$) scalar polarizabilities are fundamental properties related to the internal structure of the nucleon. They play a crucial role not only in our understanding of the nucleon, but also in other areas such as atomic physics. In the past, the values of $\alpha_{\text{E}1}$ and $\beta_{\text{M}1}$ were determined from the...
Using Polyakov loop correlators, we calculate the quark potential and energy density profile in pure SU(3) Yang-Mills theory. We investigate the limiting case where the string in baryonic quark configuration approaches the behavior of mesonic strings. We compare the potential and the energy density width profile of diquark-quark and mesonic strings. For isosceles triangular quark...
We study four-point functions of bilinear quark currents in QCD at large-Nc and obtain conditions for the existence of narrow tetraquark states. We then discuss three-point functions involving one tetraquark interpolating current and two biblinear quark currents and obtain the large-Nc behavior of the tetraquark decay constants. Finally, we discuss the implications of these results for the...
We continue previous studies of O(N) sigma models whose symmetry suffers of a spontaneous breaking down to O(N-1). We also consider soft explicit breaking terms, first, through an ad hoc variation of the potential and, in a second step, via one-loop corrections to the effective potential. These models are of a high interest for beyond Standard Model extensions (the minimally composite Higgs...
The $J/\psi\to \gamma\eta_{c}$ branching fraction was first measured in $1986$ by the Crystal Ball Collaboration in the inclusive photon spectrum and the value ${\cal B}(J/\psi\to \gamma\eta_{c}\to \gamma X)=(1.27\pm0.36)\%$ was obtained. There are many theoretical predictions for this decay rate, based on potential models, QCD sum rules, nonrelativistic EFTs and lattice QCD, but as a rule...
The coherent inelastic processes of the type $a \rightarrow b$, which may take place in the interaction of hadrons and $\gamma$ quanta with nuclei at very high energies (the nucleus remains the same), are theoretically investigated. For taking into account the influence of matter inside the nucleus, the optical model based on the concept of
refraction index is applied. Analytical formulas for...
We study the decays of two nonets of excited vector mesons which predominantly correspond to $n \hspace{0.15cm} ^{2s+1}L_J = 2 ^{3}S_{1}$ (radially excited vector mesons) and $n \hspace{0.15cm}^{2s+1}L_J = 1 ^{3}D_{1}$ (angular-momentum excited vector mesons). By using a quantum field theoretical approach we evoluate the decay widths of these mesons into two pseudoscalar mesons and into...
Since 2010, candidates for the highly excited states of charmed mesons have been successively observed by the BABAR and LHCb collaborations. Although several theoretical studies have been done, spectroscopic assignments for these states still remain to be completely elucidated.
In this work, following our previous work [1], we study extensively the pionic decays of the radial and highly...
A comparison of experimentally observed excited nucleon states to model predictions or lattice QCD calculations is made, large differences arise, specifically concering the number of excited states. In order to fully understand the strong interaction in the non-perturbative region, the excitation spectrum of nucleons is an important tool to use. The electromagnetic coupling of photons to...
Spin correlations for the $\Lambda\Lambda$ and
$\Lambda\bar{\Lambda}$ pairs, produced in relativistic heavy-ion collisions, and related angular correlations at the joint registration of space-parity nonconserving hadronic decays
of two hyperons are theoretically analyzed. These correlations give important information about the character and mechanism of multiple processes, and the advantage of...
We measure the inclusive production cross sections of hyperons and
charmed baryons from e+e- annihilation using a 800 fb-1 data sample
taken near the Υ(4S) resonance with the Belle detector at the KEKB
asymmetric-energy e+e- collider. The feed-down contributions from
heavy particles are subtracted using our data, and the direct
production cross sections are compared for the first time. The...
A new alternate chi_c0(2P) charmonium state, X*(3860), has been observed
with a significance of 6.5sigma using full amplitude analysis of the
process e+e- -> J/psi D Dbar. We also perform search for
exotic states such as hidden-strangeness penta-quark.
All the results presented here exploits the full data set of Belle.
In analogy to the QED, we analyze the polarizations of gluon and clarify the role of colours within gluons. The effect of polarizations is associated with the spin angular momentum of gluon. Consequently we point out the dependence between colour field and angular-momentum, which can give us an explanation why we cannot confirm the total angular momentum of a high-energy scattering system....
We have analyzed the $\gamma p \rightarrow p \pi^0 \eta$ process with a particular focus on the role of the triangle singularity which appears in the decay of the $\Delta(1700)$ into $\eta \Delta(1232)$,
where the $\Delta(1232)$ goes into $p$ emitting a $\pi^0$, while the $N(1535)$ is formed from the $\eta p$ interaction.
In addition to the triangle diagram, we take account of the tree level...
How much information is added to the Review of Particle
Physics when a new decay branching ratio of a hadron is measured and
reported? This is quantifiable by Shannon's information entropy. It may
be used at two levels, the distribution of decay-channel probabilities,
and the distribution of individual quantum-state probabilities
(integrating the later provides the former). We illustrate...
We introduce a non-relativistic framework to study the spectroscopy of hadronic bound states composed of four charm quarks in the diquark-antidiquark picture. By numerically solving the Schr\"{o}dinger equation with two different Cornell-inspired potentials in a similar way of heavy quarkonium models of mesons, we factorize the 4-body problem into three 2-body systems: first the diquark and...
Pion production in NN collisions is one of the sources of information on the NN
interaction and on the contribution of nucleon resonances. In particular, two-pion production in the few energy range, carries information both on $\pi\pi$ dynamics and on single and double baryon excitation.
The High Acceptance Di-Electron Spectrometer (HADES) [1] installed at GSI Helmholtz-Zentrum für...
In this work, we study the properties of the light baryons employing a constituent quark model in the hypercentral approach. The model considers through the interacting potential one-gluon exchange, Goldstone boson exchange and confinement, aspects of underlying theory, quantum chromodynamics. We introduce three different potential models and solve Schrodinger equation of the baryonic system...
In this work a continuation of an analysis of fine structure effects in nuclear
data is combined with the analysis of particle mass data.
The material used in the work is based on nuclear data compilations collected
in PNPI and data from the Compilations PDG-2016 and the evaluation CODATA.
These data provide a base for the combined analysis of all existing information
for suggested by...
By breaking the initial SU(N) symmetry, we derive the Lagrangian[1] governing the dynamics of the massive scalar particles, which can be treated as the octet of the pseudoscalar mesons. The contribution of both the quark-gluon interaction and self-interaction gluon fields into the masses of the octet of particles is considered. Provided that the hadronization of the confinement matter...
Even though the mechanism is still under discussion, the intrinsic heavy quark mechanism is a rigorous prediction of Quantum Chromodynamics.
Assuming this mechanism to exist, in our talk we discuss how we can naturally explain one of the most intriguing and surprising results in modern baryonic physics, namely the production properties of the double charmed baryons measured by the SELEX...
Using the analogy with the problem of ionization and
excitation of atoms at the propagation of relativistic charged particles through matter, the process of Coulomb dissociation of weakly bound relativistic nuclei and hypernuclei is theoretically investigated in the framework of the two-cluster deuteron-like model. Explicit expressions for the total cross-section of Coulomb disintegration of...
We study the ρB∗B¯∗ three-body system solving the Faddeev equations in the fixed center approximation. We assume the B∗B¯∗ system forming a cluster, and in terms of the two-body ρB∗ unitarized scattering amplitudes in the local Hidden Gauge approach we find a new I(J^PC)=1(3^−−) state. The mass of the new state corresponds to a two particle invariant mass of the ρB∗ system close to the...
During last decade properties of the tetraquark states, which may play an essential role in understanding of hadron dynamics, are among widely discussed problems in the literature. In this work we investigate the thermal features of the state X(3872) with the quantum numbers JPC = 1++. We consider it as a diquark-antidiquark bound state and use QCD sum rule method to explore the nature of...
Themal shifts and fluctuations at finite temperature below the deconfinement crossover from hadronic matter to the quark-gluon plasma provide a viable way to look for missing states with given quantum number in the hadronic spectrum. We study a realization of the hadron resonance gas (HRG) model in the light quark (uds) flavour sector of QCD to study the fluctuations of baryon number, charge...
We report on a recent study of the Bsπ and BK¯ interactions in finite volume [1]. We show the discrete energy levels in two scenarios whether the coupled channel interactions are either strong enough to dynamically generate the X(5568) or too weak to produce it. Supplemented by the state of the art lattice QCD simulations, our study supports the picture that the interactions are weak and the...
