82 research outputs found

    Spectroscopy of the hidden-charm [qc][qˉcˉ][qc][\bar q \bar c] and [sc][sˉcˉ][sc][\bar s \bar c] tetraquarks

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    We calculate the spectrum of qqˉccˉq\bar q c \bar c and ssˉccˉs\bar s c \bar c tetraquarks, where qq, ss and cc stand for light (u,du,d), strange and charm quarks, respectively, in a relativized diquark model, characterized by one-gluon-exchange (OGE) plus confining potential. In the diquark model, a qqˉccˉq\bar q c \bar c (ssˉccˉs\bar s c \bar c) tetraquark configuration is made up of a heavy-light diquark, qcq c (scsc), and anti-diquark, qˉcˉ\bar q \bar c (sˉcˉ\bar s \bar c). According to our results, 13 charmonium-like observed states can be accommodated in the tetraquark picture, both in the hidden-charm (qqˉccˉq\bar q c \bar c) and hidden-charm hidden-strange (ssˉccˉs\bar s c \bar c) sectors.Comment: Discussions extended, references adde

    Heavy Quark Spin Symmetry Violating Hadronic Transitions of Higher Charmonia

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    In heavy quarkonia, hadronic transitions serve as an enlightened probe for the structure and help to establish the understanding of light quark coupling with a heavy degree of freedom. Moreover, in recent years, hadronic transitions revealed remarkable discoveries to identify the new conventional heavy quarkonia and extracting useful information about the so called "XYZ" exotic states. In this contribution, we present our predictions for heavy quark spin symmetry (HQSS) breaking hadronic transitions of higher SS and DD wave vector charmonia based on our recently proposed model (inspired by Nambu-Jona-Lasinio (NJL) model) to create light meson(s) in heavy quarkonium transitions. We also suggest spectroscopic quantum numbers (2S+1LJ)(^{2S+1}L_J) for several observed charmoniumlike states. Our analysis indicates that the Y(4360)Y(4360) is most likely to be a 3D3D dominant state.Comment: Proceedings of the talk presented at "XVII International Conference on Hadron Spectroscopy and Structure (Hadron2017)", 25-29 September 2017, Salamanca, Spai

    Tetraquark mass relations in quark and diquark models

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    We present new linear relations among the masses of S-wave tetraquarks with either one flavour (QQQˉQˉQQ \bar Q \bar Q) or two (QQqˉqˉQQ\bar q \bar q). Because the relations are sensitive to the hidden-colour, spin, and spatial degrees of freedom, comparison to experimental data can help to reveal the internal structure of tetraquarks, and discriminate among different theoretical models. Depending on the model, the relations are either exact, or valid in perturbation theory, and a thorough comparison with existing literature confirms their validity at the MeV level. Additionally, we explore the connections among tetraquark models, and show how those with effective (quark or diquark) masses are related to dynamical potential models. We also show how the spectrum of diquark models is effectively a limiting case of (more general) quark models, and in particular, that the diquark concept is most relevant in the particular combination QQqˉqˉQQ\bar q \bar q, where QQ is much heavier than qˉ\bar q.Comment: Published versio

    Structure of cccˉcˉcc \bar c \bar c tetraquarks and interpretation of LHC states

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    Motivated by recent experimental evidence for apparent cccˉcˉcc\bar c \bar c states at LHCb, CMS and ATLAS, we consider how the mass spectrum and decays of such states can be used to discriminate among their possible theoretical interpretations, with a particular focus on identifying whether quarks or diquarks are the most relevant degrees of freedom. Our preferred scenario is that X(6600)X(6600) and its apparent partner state X(6400)X(6400) are the tensor (2++)(2^{++}) and scalar (0++)(0^{++}) states of an S-wave multiplet of cccˉcˉcc\bar c \bar c states. Using tetraquark mass relations which are independent of (or only weakly dependent on) model parameters, we give predictions for the masses of additional partner states with axial and scalar quantum numbers. Additionally, we give predictions for relations among decay branching fractions to J/ψJ/ψJ/\psi J/\psi, J/ψηcJ/\psi \eta_c, ηcηc\eta_c\eta_c and D(∗)Dˉ(∗)D^{(*)} \bar{D}^{(*)} channels. The scenario we consider is consistent with existing experimental data on J/ψJ/ψJ/\psi J/\psi, and our predictions for partner states and their decays can be confronted with future experimental data, to discriminate between quark and diquark models

    Evaluation of anxiety and depression in chronic liver disease patients.

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    Objective: To evaluate the risk factors of anxiety and depression in chronic liver disease patientsMethodology: In this longitudinal study seven hundred fifty-five patients (mean age 51+ 5 years, 59% males). All the patients were suffering from chronic hepatitis B, chronic Hepatitis C, Alcoholic liver disease and non-alcoholic fatty stomach disease. Questionnaires were included anxiety, using the Hamilton depressing rating scale (HDRS) and Hamilton anxiety scale (HARS), including socio-demographic, health status and family support. The criteria for inclusion in the study were having liver disease from last 15 months. Clinical functional and psychological assessments were performed.Results: In this study patients with depression was 59.3%, with anxiety 17.4% patients and both anxiety and depression were noted in 36.7% patients. After measuring and calculating all the variables score of depression and anxiety were recorded. A higher HDRS score was noted in patients older than 46 years (p=0.024). Patients with gastrointestinal bleeding had a prominent higher score of anxiety than those without bleeding (p=0.019). A higher HARS score was present in the women (p=0.011), unemployed patients (p=0.009) and those with alcoholic liver disease (p=0.006). There was direct correlation between the duration of disease and the value of HDRA and HARS score.Conclusion: In the chronic liver disease patients’ depression and anxiety are increasingly high with passage of time, gastrointestinal bleeding and unemployment. Increased prevalence of relax by patients are more likely to be due to the low acceptance of disease prognosis

    Spectroscopy and decays of the fully-heavy tetraquarks

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    We discuss the possible existence of the fully-heavy tetraquarks. We calculate the ground-state energy of the bbbˉbˉbb \bar b \bar b bound state, where bb stands for the bottom quark, in a nonrelativistic effective field theory framework with one-gluon-exchange (OGE) color Coulomb interaction, and in a relativized diquark model characterized by OGE plus a confining potential. Our analysis advocates the existence of uni-flavor heavy four-quark bound states. The ground state bbbˉbˉbb\bar b\bar b tetraquark mass is predicted to be (18.72±0.02)(18.72\pm0.02)~GeV. Mass inequality relations among the lowest QQQˉQˉQQ\bar{Q}\bar{Q} state, where Q∈{c,b}Q\in \{c, b\}, and the corresponding heavy quarkonia are presented, which give the upper limit on the mass of ground state QQQˉQˉQQ\bar{Q}\bar{Q}. The possible decays of the lowest bbbˉbˉbb\bar{b}\bar{b} are highlighted, which might provide useful references in the search for them in ongoing LHC experiments, and its width is estimated to be a few tens of MeV.Comment: Version accepted for publication in Eur. Phys. J.

    χb(3P)\chi_{b}(3P) Multiplet Revisited: Ultrafine Mass Splitting and Radiative Transitions

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    Invoked by the recent CMS observation regarding candidates of the χb(3P)\chi_b(3P) multiplet, we analyze the ultrafine and mass splittings among 3P3P multiplet in our unquenched quark model (UQM) studies. The mass difference of χb2\chi_{b2} and χb1\chi_{b1} in 3P3P multiplet measured by CMS collaboration (10.6±0.64±0.1710.6 \pm 0.64 \pm 0.17 MeV) is very close to our theoretical prediction (1212 MeV). Our corresponding mass splitting of χb1\chi_{b1} and χb0\chi_{b0} enables us to predict more precisely the mass of χb0(3P)\chi_{b0}(3P) to be (10490±310490\pm 3) MeV. Moreover, we predict ratios of the radiative decays of χbJ(nP)\chi_{bJ}(nP) candidates, both in UQM and quark potential model. Our predicted relative branching fraction of χb0(3P)→Υ(3S)γ\chi_{b0}(3P)\to\Upsilon(3S)\gamma is one order of magnitude smaller than χb2(3P)\chi_{b2}(3P), this naturally explains the non-observation of χb0(3P)\chi_{b0}(3P) in recent CMS search. We hope these results might provide useful references for forthcoming experimental searches

    An in silico approach to analyze HCV genotype-specific binding-site variation and its effect on drug-protein interaction

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    Genotype variation in viruses can affect the response of antiviral treatment. Several studies have established approaches to determine genotype-specific variations; however, analyses to determine the effect of these variations on drug-protein interactions remain unraveled. We present an in-silico approach to explore genotype-specific variations and their effect on drug-protein interaction. We have used HCV NS3 helicase and fluoroquinolones as a model for drug-protein interaction and have investigated the effect of amino acid variations in HCV NS3 of genotype 1a, 1b, 2b and 3a on NS3-fluoroquinolone interaction. We retrieved 687, 667, 101 and 248 nucleotide sequences of HCV NS3 genotypes 1a, 1b, 2b, and 3a, respectively, and translated these into amino acid sequences and used for genotype variation analysis, and also to construct 3D protein models for 2b and 3a genotypes. For 1a and 1b, crystal structures were used. Drug-protein interactions were determined using molecular docking analyses. Our results revealed that individual genotype-specific HCV NS3 showed substantial sequence heterogeneity that resulted in variations in docking interactions. We believe that our approach can be extrapolated to include other viruses to study the clinical significance of genotype-specific variations in drug-protein interactions
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