Mass spectrum and leptonic decay constants of ground and radially excited states of ηc and ηb in a Bethe–Salpeter equation framework

2015 ◽  
Vol 24 (04) ◽  
pp. 1550030 ◽  
Author(s):  
Hluf Negash ◽  
Shashank Bhatnagar
Keyword(s):  
Mass Spectrum ◽  
Excited States ◽  
Ground State ◽  
Reasonable Agreement ◽  
Equal Mass ◽  
Leptonic Decay ◽  
Decay Constants ◽  
Pseudoscalar Mesons

In this paper, we study the mass spectrum and decay constants of ground state (1S) and radially excited states (2S and 3S) of heavy equal mass pseudoscalar mesons, ηc and ηb. We have employed the framework of Bethe–Salpeter equation (BSE) under Covariant Instantaneous Ansatz (CIA). Our predictions are in reasonable agreement with the data on available states and results of other models.

scholarly journals Radiative Decay Widths of Ground and Excited States of Vector Charmonium and Bottomonium

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Hluf Negash ◽  
Shashank Bhatnagar
Keyword(s):  
Mass Spectrum ◽  
Excited States ◽  
Mass Spectra ◽  
Reasonable Agreement ◽  
Radiative Decay ◽  
Decay Constants ◽  
Two Photon ◽  
Quantum Numbers ◽  
Decay Widths ◽  
Input Parameters

We study the radiative decay widths of vector quarkonia for the process of J/ψ(nS)→ηc(nS)γ and Υ(nS)→ηb(nS)γ (for principal quantum numbers n=1,2,3) in the framework of Bethe-Salpeter equation under the covariant instantaneous ansatz using a 4×4 form of BSE. The parameters of the framework were determined by a fit to the mass spectrum of ground states of pseudoscalar and vector quarkonia, such as ηc, ηb, J/ψ, and Υ. These input parameters so fixed were found to give good agreements with data on mass spectra of ground and excited states of pseudoscalar and vector quarkonia, leptonic decay constants of pseudoscalar and vector quarkonia, two-photon decays, and two-gluon decays of pseudoscalar quarkonia in our recent paper. With these input parameters so fixed, the radiative decay widths of ground (1S) and excited (2S,3S) states of heavy vector quarkonia (J/Ψ and Υ) are calculated and found to be in reasonable agreement with data.

SPECTROSCOPY OF LIGHT HADRONS ON ANISOTROPIC LATTICES

2006 ◽  
Vol 21 (26) ◽  
pp. 5253-5274
Author(s):  
FRANK X. LEE
Keyword(s):  
Mass Spectrum ◽  
Lattice Qcd ◽  
Excited States ◽  
Ground State ◽  
Quark Mass ◽  
Tree Level ◽  
Mass Dependence ◽  
Anisotropic Lattices ◽  
Quark Mass Dependence ◽  
The Masses

The mass spectrum of spin-1/2 baryons in both parity channels is computed using the methods of lattice QCD in the quenched approximation. An anisotropic action with anisotropy as/at = 3 is employed, using tree-level coefficients with tadpole improvement. Clear splittings from the nucleon ground state are observed with smeared operators and 500 configurations. Methods for extracting the first excited states are investigated. Using the quark mass dependence of the masses, qualitative comparisons are made with previous calculations and experiment.

WEAK LEPTONIC DECAY OF LIGHT AND HEAVY PSEUDOSCALAR MESONS IN A FIELD-THEORETIC QUARK MODEL

1993 ◽  
Vol 08 (29) ◽  
pp. 2775-2783 ◽  
Author(s):  
L. MAHARANA ◽  
A. NATH ◽  
A. R. PANDA
Keyword(s):  
Harmonic Oscillator ◽  
Quark Model ◽  
Constituent Quark ◽  
Leptonic Decay ◽  
Decay Constants ◽  
Quark Masses ◽  
Leptonic Decays ◽  
Pseudoscalar Mesons ◽  
Oscillator Wave Function ◽  
Harmonic Oscillator Wave Function

Weak leptonic decays of light and heavy pseudoscalar mesons are studied in a field-theoretic quark model where the mesons are described by constituent quarks and antiquarks with a particular ansatz and a Harmonic oscillator wave function. With constituent quark masses and Harmonic oscillator radii for mesons as parameters of the model, decay constants are calculated and found as (fπ, fk, fD, fB) = (132 MeV , 161 MeV , 160 MeV , 115 MeV ) indicating a reasonable agreement with the experimental data wherever available. Partial decay widths and branching ratios for kinematically allowed leptonic decay processes are also estimated and compared with the experiments wherever available.

scholarly journals MESON DECAY IN AN INDEPENDENT QUARK MODEL

2000 ◽  
Vol 09 (05) ◽  
pp. 407-415 ◽  
Author(s):  
HAKAN CİFTCİ ◽  
HÜSEYIN KORU
Keyword(s):  
Experimental Data ◽  
Quark Model ◽  
Weak Decay ◽  
Leptonic Decay ◽  
Meson Decay ◽  
Decay Constants ◽  
Pseudoscalar Mesons ◽  
Light Vector ◽  
Decay Widths ◽  
Good Agreement

Leptonic decay widths and leptonic decay constants of light vector mesons and weak leptonic decay widths and weak decay constants of light and heavy pseudoscalar mesons have been studied in a field-theoretic framework based on the independent quark model with a scalar-vector power-law potential. The results are in very good agreement with the experimental data.

scholarly journals Spectroscopy of ground and excited states of pseudoscalar and vector charmonium and bottomonium

2016 ◽  
Vol 25 (08) ◽  
pp. 1650059 ◽  
Author(s):  
Hluf Negash ◽  
Shashank Bhatnagar
Keyword(s):  
Mass Spectrum ◽  
Excited States ◽  
Weak Decay ◽  
Mass Spectral ◽  
Decay Constants ◽  
Photon Decay ◽  
Oscillator Basis ◽  
Decay Widths ◽  
State Formula ◽  
Spectral Equation

In this paper, we calculate the mass spectrum, weak decay constants, two photon decay widths, and two-gluon decay widths of ground ([Formula: see text]) and radially excited ([Formula: see text]) states of pseudoscalar charmoniuum and bottomonium such as [Formula: see text] and [Formula: see text], as well as the mass spectrum and leptonic decay constants of ground state ([Formula: see text]), excited ([Formula: see text]) states of vector charmonium and bottomonium such as [Formula: see text], and [Formula: see text], using the formulation of Bethe–Salpeter equation under covariant instantaneous ansatz (CIA). Our results are in good agreement with data (where ever available) and other models. In this framework, from the beginning, we employ a [Formula: see text] representation for two-body ([Formula: see text]) BS amplitude for calculating both the mass spectra as well as the transition amplitudes. However, the price we have to pay is to solve a coupled set of equations for both pseudoscalar and vector quarkonia, which we have explicitly shown get decoupled in the heavy-quark approximation, leading to mass spectral equation with analytical solutions for both masses, as well as eigenfunctions for all the above states, in an approximate harmonic oscillator basis. The analytical forms of eigenfunctions for ground and excited states so obtained are used to evaluate the decay constants and decay widths for different processes.

scholarly journals Revisit the tetraquark candidates in the J/ψJ/ψ mass spectrum

2021 ◽  
Vol 36 (02) ◽  
pp. 2150014
Author(s):  
Zhi-Gang Wang
Keyword(s):  
Mass Spectrum ◽  
Excited States ◽  
Ground State ◽  
Sum Rules ◽  
Qcd Sum Rules ◽  
Text Type ◽  
State Formula ◽  
Broad Structure ◽  
Basic Constituent

In this paper, we introduce a relative [Formula: see text]-wave to construct the doubly-charm axialvector diquark operator, then take the doubly-charm axialvector (anti-)diquark operator as the basic constituent to construct the scalar and tensor tetraquark currents to study the scalar, axialvector and tensor fully-charm tetraquark states with the QCD sum rules. We observe that the ground state [Formula: see text]-type tetraquark states and the first radial excited states of the [Formula: see text]-type tetraquark states have almost degenerated masses, where the [Formula: see text] and [Formula: see text] stand for the diquark operators with and without the relative [Formula: see text]-wave, respectively, the broad structure above the [Formula: see text] threshold maybe consist of several diquark–antidiquark-type fully-charm tetraquark states.

Excited-State Dynamics in the RNA Nucleotide Uridine 5’-Monophosphate Investigated by Femtosecond Broadband Transient Absorption Spectroscopy

2019 ◽  
Author(s):  
Matthew M. Brister ◽  
Carlos Crespo-Hernández
Keyword(s):  
Excited State ◽  
Excited States ◽  
Ground State ◽  
Transient Absorption ◽  
Electronic Energy ◽  
Transient Absorption Spectroscopy ◽  
Electronic Relaxation ◽  
Vibrationally Excited ◽  
Excited State Dynamics ◽  
Π State

<p></p><p> Damage to RNA from ultraviolet radiation induce chemical modifications to the nucleobases. Unraveling the excited states involved in these reactions is essential, but investigations aimed at understanding the electronic-energy relaxation pathways of the RNA nucleotide uridine 5’-monophosphate (UMP) have not received enough attention. In this Letter, the excited-state dynamics of UMP is investigated in aqueous solution. Excitation at 267 nm results in a trifurcation event that leads to the simultaneous population of the vibrationally-excited ground state, a longlived <sup>1</sup>n<sub>O</sub>π* state, and a receiver triplet state within 200 fs. The receiver state internally convert to the long-lived <sup>3</sup>ππ* state in an ultrafast time scale. The results elucidate the electronic relaxation pathways and clarify earlier transient absorption experiments performed for uracil derivatives in solution. This mechanistic information is important because long-lived nπ* and ππ* excited states of both singlet and triplet multiplicities are thought to lead to the formation of harmful photoproducts.</p><p></p>

Charge Transfer Between CO22+ and Ar or Ne at Collision Energies 3-10 eV

2003 ◽  
Vol 68 (1) ◽  
pp. 178-188 ◽  
Author(s):  
Libor Mrázek ◽  
Ján Žabka ◽  
Zdeněk Dolejšek ◽  
Zdeněk Herman
Keyword(s):  
Charge Transfer ◽  
Excited States ◽  
Ground State ◽  
Scattering Method ◽  
Translational Energy ◽  
Centre Of Mass ◽  
Energy Distributions ◽  
Zener Model ◽  
Beam Scattering ◽  
Product Ions

The beam scattering method was used to investigate non-dissociative single-electron charge transfer between the molecular dication CO22+ and Ar or Ne at several collision energies between 3-10 eV (centre-of-mass, c.m.). Relative translational energy distributions of the product ions showed that in the reaction with Ar the CO2+ product was mainly formed in reactions of the ground state of the dication, CO22+(X3Σg-), leading to the excited states of the product CO2+(A2Πu) and CO2+(B2Σu+). In the reaction with Ne, the largest probability had the process from the reactant dication excited state CO22+(1Σg+) leading to the product ion ground state CO2+(X2Πg). Less probable were processes between the other excited states of the dication CO22+, (1∆g), (1Σu-), (3∆u), also leading to the product ion ground state CO2+(X2Πg). Using the Landau-Zener model of the reaction window, relative populations of the ground and excited states of the dication CO22+ in the reactant beam were roughly estimated as (X3Σg):(1∆g):(1Σg+):(1Σu-):(3∆u) = 1.0:0.6:0.5:0.25:0.25.

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