Search

Motivated by the discovery of the fully charmed tetraquark state $X(6900)$ in the invariant mass spectrum of $J/\psi$ pairs by the LHCb collaboration, this study explores the potential existence of fully heavy pentaquark states. We systematically investigate the low-lying s-wave fully heavy pentaquark states across all possible configurations. The classification of these states is performed using the Young-Yamounachi bases through the Young-tableau technique. We analyze the mass spectrum and magnetic moments of pentaquarks with quantum numbers $J^P$= $\frac{1}{2}^{\pm}$,$\frac{3}{2}^{\pm}$ and $\frac{5}{2}^{\pm}$ utilizing effective mass and screened charge schemes. Our findings are compared with various theoretical models, providing valuable insights for future experimental studies.

We investigated the electromagnetic quadrupole transition of baryon decuplet ($J^P= \frac{3}{2}^+$) to octet ($J^P= \frac{1}{2}^+$) using the statistical framework together with the principle of detailed balance. The statistical approach assumed the expansion of hadrons in terms of various quark-gluon Fock states. By specifying the appropriate multiplicity in spin, color $\&$ flavor space, the relative probabilities of strange and non-strange quark-gluon Fock state are calculated. These probabilities further accumulated in the form of statistical parameters, highlighting the importance of sea quarks and gluons in the electromagnetic transition. Our calculations includes the individual contribution of valence and sea (scalar, vector and tensor ) to the transition moment of baryons. The effect of flavor SU(3) symmetry and its breaking in both valence and sea quarks is studied by incorporating the strange quark mass. The strangeness in the sea is constrained by a suppression factor $(1-C_l)^{n-1}$, which depends upon the free energy of gluons. The computed results get affected upto 60 $\%$ and exhibit the dominance of octet sea. The present work has been compared with updated experimental data and various theoretical predictions. The results obtained may offer important insights for future experimental studies.

The charm ($D$) and charm-strange ($D_s$) mesons are investigated in a variational scheme using Gaussian trial wave functions. The Hamiltonian contains Song and Lin potential with a constant term dependent on radial and orbital quantum numbers. The Gaussian wave function used has a dependence on radial distance $r$, radial quantum number $n$, orbital quantum number $l$ and a trial parameter $\mu$. These wave functions are used to compute the expectation of Song and Lin potential dependent on $r$. The total energy (expectation of Hamiltonian) for each state is minimized with a parameter $\mu$ from the wavefunctions. The obtained spectra of $D$ and $D_s$ mesons are in good agreement with other theoretical models and available experimental masses. The mass spectra of $D$ and $D_s$ mesons are also used to plot Regge trajectories in the ($J$, $M^2$) and ($n_r$, $M^2$) planes. In ($J$, $M^2$) plane, both natural and unnatural parity states of $D$ and $D_s$ mesons are plotted. The trajectories are parallel and equidistant from each other. The two-body strong decays of $D$ and $D_s$ are analyzed in the framework of heavy quark effective theory using computed masses. The strong decay widths are given in terms of strong coupling constants. These couplings are also estimated by comparing them with available experimental values for observed states. Also, the partial decay width ratios of different states are analyzed and used to suggest assignments to the observed states. We have assigned the spin-parity to newly observed $D^*_{s2}(2573)$ as the strange partner of $D^*_2(2460)$ identified as $1^3P_2$, $D_1^*(2760)$ and $D^*_{s1}(2860)$ as $1^3D_1$, $D^*_3(2750)$ and $D^*_{s3}(2860)$ as $1^3D_3$, $D_2(2740)$ as $1D_2$, $D_0(2550)$ as $2^1S_0$, $D^*_1(2660)$ and $D^*_{s1}(2700)$ as $2^3S_1$, $D^*_J(3000)$ as $2^3P_0$ $D_J(3000)$ as $2P_1$, $D^*_2(3000)$ as $1^3F_2$ states., Comment: 23 pages, 6 figures

We analyze the ground state pentaquark structures with a single heavy quark ($qqqq\Bar{Q}$) using various phenomenological models. The recent observations of singly heavy tetraquark structures at LHCb serve as a significant motivation for this investigation. We studied the symmetric 15-plet configuration of SU(3) flavor representation with the spin-parity assignment of $5/2^-$, representing the symmetric spin state for the pentaquark systems. We employed an extended Gursey-Radicati mass formula and an effective mass scheme to compute the mass spectra of pentaquark states. Additionally, the methodology of the screened charge scheme is introduced to calculate the magnetic moment assignments, specifically for configurations involving both charm and bottom quarks. We also proposed the potential production modes originating from the weak decay of heavy baryons. We identified the strong decay channels where pentaquark transitions into a light baryon and a heavy meson. Our analysis of mass spectra, magnetic moments, and possible strong decay channels helps us to explore the inner structure of pentaquarks and their underlying quark dynamics. This work not only augments the theoretical frameworks used to describe such systems but is also helpful for future experimental pursuits at facilities like LHCb, fostering further experimental validations and discoveries in heavy quark spectroscopy.

We carried out the systematic analysis of the $s$-wave triply heavy pentaquarks with possible configurations like $q\Bar{q}QQQ$ and $qqQQ\Bar{Q}$, ($q = u, d, s$ and $Q = c, b$ quarks). Special unitary representations are utilized to study the classification scheme for triply heavy configurations like $q\Bar{q}QQQ$ and $qqQQ\Bar{Q}$. We classified the $q\Bar{q}QQQ$-type pentaquarks into an octet and $qqQQ\Bar{Q}$-type pentaquarks into sextet configurations with the help of SU(3) flavor representation. Also, with the help of SU(2) spin representation, we studied the possible spin assignments ($\frac{1}{2}^-$, $\frac{3}{2}^-$, and $\frac{5}{2}^-$) for ground state triply heavy pentaquarks. Furthermore, we used the formalism of the extended Gursey-Radicati mass formula and effective mass scheme to estimate the masses of triply heavy pentaquarks. Additionally, we calculated the magnetic moment assignments using the effective mass and screened charge schemes. The predicted outcomes align well with the existing theoretical data and benefit future studies. Our work provides a comprehensive framework that combines the theoretical aspects of SU(3) and SU(2) symmetries with practical predictions for observables, offering a strong foundation for experimental verification. This integrated approach enhances our understanding of the complex interactions within triply heavy pentaquarks and underscores their potential role in probing deeper into the dynamics of the strong force. These findings are crucial for designing future high-energy experiments that directly observe these exotic states and confirm their properties, paving the way for new insights into quantum chromodynamics.

By taking into light the discovery of pentaquark structures like $P_{\psi s}^\Lambda(4338)^0$, $P_c(4380)$ and $P_c(4450)$, we performed the spectroscopy of hidden-bottom pentaquarks. By utilizing special unitary representations, we systematically classified the hidden bottom pentaquarks into two distinct configurations within the SU(3) flavor representation: the octet and decuplet. In this study, we employed an extended version of the GR mass formula along with the effective mass scheme to provide estimations of the masses associated with hidden-bottom pentaquarks. Furthermore, we extend our analysis to estimate the magnetic moments using the effective mass scheme and screened charge scheme. Moreover, by employing the effective Lagrangian, we computed the partial widths for the octet configuration. This comprehensive analysis offers crucial insights into the decay mechanisms and lifetimes of these exotic particles, enhancing our understanding of their fundamental properties. Our findings, which include calculations of masses and magnetic moments, demonstrate reasonable agreement with existing theoretical predictions., Comment: arXiv admin note: text overlap with arXiv:2401.02146

Motivated by the recent discovery of single heavy tetraquark structures, $T_{c\bar{s}0}^a (2900)^{++}$ and $T_{c\bar{s}0}^a(2900)^0$ by the LHCb collaboration, masses and magnetic moments of singly heavy pentaquark states are estimated in this work. To classify the singly heavy pentaquark structures, we employ the special unitary representation. By using the SU(3) flavor representation, we placed singly heavy pentaquark states into the allowed flavor multiples. Also, by using the extension of the Gursey-Radicati mass formula and the effective mass scheme, we estimated the masses of singly heavy pentaquark states. Further, magnetic moments of these states have been calculated using the effective mass and the screened charge techniques. A thorough comparison of our results shows reasonable agreement with the available theoretical data and may be helpful for future experimental studies.

In this paper, we comprehensively explore bottomonia mass spectra and their decay properties by solving the non-relativistic Schrodinger wave equation numerically with approximate quark-antiquark potential form. We also incorporate spin-dependent terms - spin-spin, spin-orbit, and tensor terms to remove mass degeneracy and to obtain excited states ($nS, nP, nD, nF, n = 1, 2, 3, 4, 5$) mass spectra. By using Van Royen - Weisskopf formula, we investigate leptonic decay constants, di-leptonic, di-gamma, tri-gamma, di-gluon decay widths and also incorporate first-order radiative corrections. We also computed radiative transition widths, which give a better insight into the non-perturbative aspects of QCD. The present results for mass spectroscopy and decay properties are in tune with available experimental values and other theoretical predictions. Our results may provide better insight to upcoming experimental information in the near future., Comment: 19 Pages, 12 tables

An operator formalism is used on the wavefunction of baryons to compute their charge radii and quadrupole moments. Total anti-symmetric wavefunction in spin, color and flavor space is framed for $J^P=\frac{1}{2}^+$ nucleons and $J^P=\frac{3}{2}^+$ hyperons. To understand the importance of sea, statistical model is used in conjugation with the detailed balance principle. Within the statistical approach, the importance of sea with quarks and gluons are studied using the relevant probabilities that are associated with spin, flavor, and color space. The present work also focuses on individual contributions of valence and sea which contains terms of scalar, vector and tensor sea. The obtained results are in agreement with available theories and few experimental outcomes. Our computed results may provide important information for upcoming experimental findings.

In this work, the multiquark approach is used to analyze the spectroscopy of hidden-charm pentaquark states, motivated by recent discoveries at the LHCb collaboration. Using the SU(3) flavor representation, pentaquarks having $J^P = 5/2^-$ are arranged into 10 (decuplet) of the SU(3) flavor multiplets. The masses of pentaquarks are calculated using the extension of the Gursey-Radicati mass formula and the effective mass scheme. Also, we calculated the magnetic moments of the hidden-charm pentaquarks using the effective mass and shielded charge technique. Further, we suggested the possible production modes for $J^P = 5/2^-$ pentaquarks from the decay of bottom baryons, which consist of pentaquark states as intermediate states. Our results for masses demonstrate reasonable agreement with the available data and our analysis for both masses and magnetic moments may be useful for future experimental studies.

We studied $F$-wave bottom mesons in heavy quark effective theory. The available experimental and theoretical data is used to calculate the masses of $F$-wave bottom mesons. The decay widths of bottom mesons are analyzed to find upper bounds of the associated couplings. We also construct Regge trajectories for our predicted data in planes ($J$, $M^2$ ) and our results nicely fit on Regge lines. Our results may provide a crucial information for upcoming experimental studies., Comment: 12 pages, 4 figure. arXiv admin note: text overlap with arXiv:2201.01936

Tetraquark states are classified using the $SU(6)_{sf}$ spin-flavor symmetry and Young tableau technique. Further, by using the extension of Gursey-Radicati mass formula, masses of tetraquark states are predicted upto good level of accuracy. Also, Decay channels and decay widths of tetraquark states are calculated and found to be in good agreement with the experimental and available theoretical data., Comment: 12 pages , 4 figures

By exploring heavy quark effective theory (HQET), we use theoretical available data for bottom mesons to analysis the masses and decays for n = 3 charm mesons. From the predicted masses, we studied ground state strong decay modes in terms of couplings. Comparing the decays with available total decay widths, we provide upper bounds on the associated couplings. We also plot Regge trajectories for our predicted data in planes (J, $M^2$ ) and ($n_r$, $M^2$ ) and estimated higher masses (n = 4) by fixing Regge slopes and intercepts. These Regge trajectories are used to clarify $D_2^*(3000)$ state's $J^P$ as 1F ($2^+$) state. The presented results may further get confirmation through upcoming experimental information., Comment: 9 pages,7 figures

The statistical model in combination with detailed balance principle is able to phenomenological calculate and analyze spin and flavor dependent properties like magnetic moments (with effective masses, effective charge, with both effective mass and effective charge), quark spin polarization and distribution, strangeness suppression factor. The magnetic moments of the octet baryons are analyzed within the statistical model, by putting emphasis on the SU(3) symmetry breaking effects generated by the mass difference between the strange and non strange quarks. The work presented here assume hadrons with a sea having admixture of quark-gluon Fock states. The results obtained have been compared with theoretical models and experimental data., Comment: 12 Pages, 5 Tables

The mass formulae for the baryon octet and decuplet are calculated. These formulae are function of constituent quark masses and spin spin interaction terms for the quarks inside the baryons. The coefficients in the mass formulae is estimated by the statistical model for J/P=1/2+, J/P=3/2+, incorporating the contributions from \sea" containing uu; dd; ss pairs and gluons . The measured masses are presented and found to be matching good with some of the experimental and theoretical data., Comment: 14 pages, 4 tables

Recently LHCb predicted spin 1 and spin 3 states D* s1(2860) and D* s3(2860) which are studied through their strong decays, and are assigned to fit the 13D1and 13D3 states in the charm spectroscopy. In this paper,using the heavy quark effective theory, we state that assigning D*s1(2860) as the mixing of 13D1 - 23S1 states, is rather a better justification to its observed experimental values than a pure state. We study its decay modes variation with hadronic coupling constant gxh and the mixing angle . We appoint spin 3 state D* s3(2860) as the missing 1D 3- JP state, and also study its decay channel behavior with coupling constant gyh. To appreciate the above results, we check the variation of decay modes for their spin partners states i.e. 1D2 and 1D'2 with their masses and strong coupling constant i.e. gxh and gyh. Our calculation using HQET approach give mixing angle between the 13D1 - 23S1 state for D* s1(2860) to lie in the range (-1.6 radians < theta < -1.2 radians). Our calculation for coupling constant values gives gxh to lie between value 0:17 < gxh < 0:20 and gyh to be 0.40. We expect from experiments to observe this mixing angle to verify our results., Comment: 11 pages, 9 figure and 5 Tables, EPJC 2015 communicated

A suitable wave function for baryon decuplet is framed with inclusion of sea containing quark- gluon Fock states. Relevant operator formalism is applied to calculate magnetic moments of JP = 3 2 + baryon decuplet. Statistical model assumes decomposition of baryonic state in various quark-gluon Fock states such as jqqqijgi; jqqqijggi; jqqqijgggi with possibility gluon emitting qq pairs condensates due to the subprocesses like g , qq; g , gg and g , qg where qq = uu; dd; ss. Statistical approach and detailed balance principle in combination is used to find the relative probabilities of these Fock states in avor, spin and color space. The total number of partons (sea) in this formalism are restricted to three gluons due to limited free energy of gluon and suppressed number of strange quark-antiquark pairs. The combined approach is used to calculate the magnetic moments, importance of strangeness in the sea (scalar, vector and tensor). Our approach has confirmed the scalar-tensor sea dominancy over vector sea. Various modifications in the model are used to check the validity of statistical approach. The results are matched with theoretical data available. Good consistency with the experimental data have been achieved for Delta++, Delta+ and Omega-., Comment: 20 Pages, 7 Table and 1 figure

Using an effective Lagrangian approach based on heavy quark symmetry and chiral dynamics, we explore the strong decay widths and branching ratios of various resonances and suggest their JP find the coupling constants involved in the strong decays through pseudoscalar mesons. The present work also discusses about the possible spin-parity assignments of recently observed states by LHCb collaboration., Comment: 13 pages, 3 tables and 6 plots, 2015(EPJC: Communicated)

We present the mass formula for heavy-light charm meson for one loop, using heavy quark effective theory. Formulating an effective Lagrangian, the masses of the ground state heavy mesons have been studied in the heavy quark limit including leading corrections from finite heavy quark masses and nonzero light quark masses using a constrained fit for the eight equation having eleven parameters including three coupling constants g, h and g'. Masses determined from this approach is fitted to the experimentally known decay widths to estimate the strong coupling constants, showing a better match with available theoretical and experimental data, Comment: 16 pages and 12 figures. arXiv admin note: text overlap with arXiv:hep-ph/0503134 by other authors

We conclude that nucleon is a many body complex system whose low-energy behaviour is determined mainly by strong interaction. Non-perturbative approach to QCD, such as QCD sum rule and the QCD based effective theory, and the models such as a statistical model, have a complementary role in exposing different aspects of nucleonic properties., Comment: Ph.D Thesis submitted(2006),120 Pages, M.S University of Baroda, Vadodara

Gluonic contributions to the self-energy of a nucleon have been investigated in an effective theory. The couplings of the topological charge density to nucleons give rise to OZI violating nucleon interactions. The one-loop self-energy of a nucleon arising due to these interactions have been calculated using a heavy baryon chiral perturbation theory. The divergences have been regularized using form factors. The nontrivial structure of the QCD vacuum has also been taken into account., Comment: 10 Pages, 2 figures

Using the vacuum-to-pion matrix element of the correlation function of the interpolating fields of the two nucleons, the isospin splitting in the diagonal pion-nucleon coupling constant has been studied in the framework of the conventional QCD sum rule. Some of the implications of this splitting has also been discussed., Comment: 13 pages, 4 Figures and 1 Table

We decompose various quark-gluon Fock states of a nucleon in a set of states in which each of the three-quark core and the rest of the stuff, termed as a sea, appears with definite spin and color quantum number, their weight being determined, statistically, from their multiplicities. The expansion coefficients in the quark-gluon Fock states have been taken from a recently proposed statistical model. We have also considered two modifications of this model with a view to reduce the contributions of the sea components with higher multiplicities. With certain approximations, we have calculated the quark contributions to the spin of the nucleon,the ratio of the magnetic moments of nucleons, their weak decay constant, and the ratio of SU(3) reduced matrix elements for the axial current. A reasonably close agreement with the corresponding experimental values have been obtained in all the three cases., Comment: 19 pages