scholarly journals Spectrum of scalar and pseudoscalar glueballs from functional methods

2020 ◽  
Vol 80 (11) ◽  
Author(s):  
Markus Q. Huber ◽  
Christian S. Fischer ◽  
Hèlios Sanchis-Alepuz

AbstractWe provide results for the spectrum of scalar and pseudoscalar glueballs in pure Yang–Mills theory using a parameter-free fully self-contained truncation of Dyson–Schwinger and Bethe–Salpeter equations. The only input, the scale, is fixed by comparison with lattice calculations. We obtain ground state masses of $$1.9\,\text {GeV}$$ 1.9 GeV and $$2.6\,\text {GeV}$$ 2.6 GeV for the scalar and pseudoscalar glueballs, respectively, and $$2.6\,\text {GeV}$$ 2.6 GeV and $$3.9\,\text {GeV}$$ 3.9 GeV for the corresponding first excited states. This is in very good quantitative agreement with available lattice results. Furthermore, we predict masses for the second excited states at $$3.7\,\text {GeV}$$ 3.7 GeV and $$4.3\,\text {GeV}$$ 4.3 GeV . The quality of the results hinges crucially on the self-consistency of the employed input. The masses are independent of a specific choice for the infrared behavior of the ghost propagator providing further evidence that this only reflects a nonperturbative gauge completion.

2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Markus Q. Huber ◽  
Christian S. Fischer ◽  
Hèlios Sanchis-Alepuz

AbstractWe calculate the glueball spectrum for spin up to $$J=$$ J = 4 and positive charge parity in pure Yang–Mills theory. We construct the full bases for $$J=$$ J = 0, 1, 2, 3, 4 and discuss the relation to gauge invariant operators. Using a fully self-contained truncation of Dyson–Schwinger equations as input, we obtain ground states and first and second excited states from extrapolations of the eigenvalue curves. Where available, we find good quantitative agreement with lattice results


2006 ◽  
Vol 21 (26) ◽  
pp. 5253-5274
Author(s):  
FRANK X. LEE

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.


2016 ◽  
Vol 25 (08) ◽  
pp. 1650053 ◽  
Author(s):  
Emre Tabar ◽  
Hakan Yakut ◽  
Ali Akbar Kuliev

The ground state magnetic moments and the low-lying magnetic dipole (Ml) transitions from the ground to excited states in heavy deformed odd-mass [Formula: see text]Ta have been microscopically investigated on the basis of the quasiparticle-phonon nuclear model (QPNM). The problem of the spurious state mixing in M1 excitations is overcome by a restoration method allowing a self-consistent determination of the separable effective restoration forces. Due to the self-consistency of the method, these effective forces contain no arbitrary parameters. The results of calculations are compared with the available experimental data, the agreement being reasonably satisfactory.


Potential energy diagrams for ground and excited states have been calculated approximately for trans stilbene and several geometrical configurations, including a planar cis form, generated by twisting about the central double bond. The calculations show that on twisting the lowest triplet 3 B becomes the most stable state, and that the π -electron distribution of this state in the perpendicular model is equivalent to separation into two benzyl systems. The lowest singlet 1 A that corresponds to the ground state in cis and trans stilbene does not separate in this way. Quantitative agreement is obtained with observed thermal and spectroscopic evidence. The potential energy diagrams provide a satisfactory interpretation of the qualitative features of the ultraviolet and fluorescent spectra, the absence of phosphorescence, and the mechanisms of the thermal, the photochemical and the photosensitized isomerization reactions.


2019 ◽  
Author(s):  
Matthew M. Brister ◽  
Carlos Crespo-Hernández

<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>


2003 ◽  
Vol 68 (1) ◽  
pp. 178-188 ◽  
Author(s):  
Libor Mrázek ◽  
Ján Žabka ◽  
Zdeněk Dolejšek ◽  
Zdeněk Herman

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.


1985 ◽  
Vol 40 (9) ◽  
pp. 913-919
Author(s):  
Juan Carlos López ◽  
José L. Alonso

Abstract The rotational transitions of 3,4-dihydro-1,2-pyran in the ground state and six vibrationally excited states have been assigned. The rotational constants for the ground state (A = 5198.1847(24), B = 4747.8716(24) and C = 2710.9161(24) have been derived by fitting μa, μb and μc-type transitions. The dipole moment was determined from Stark displacement measurements to be 1.400(8) D with its principal axis components |μa| =1.240(2), |μb| = 0.588(10) and |μc| = 0.278(8) D. A model calculation to reproduce the ground state rotational constants indicates that the data are consistent with a twisted ring conformation. The average intensity ratio gives vibrational separations between the ground and excited states of the ring-bending and ring-twisting modes of ~ 178 and ~ 277 cm-1 respectively.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Riccardo Conti ◽  
Davide Masoero

Abstract We study the large momentum limit of the monster potentials of Bazhanov-Lukyanov-Zamolodchikov, which — according to the ODE/IM correspondence — should correspond to excited states of the Quantum KdV model.We prove that the poles of these potentials asymptotically condensate about the complex equilibria of the ground state potential, and we express the leading correction to such asymptotics in terms of the roots of Wronskians of Hermite polynomials.This allows us to associate to each partition of N a unique monster potential with N roots, of which we compute the spectrum. As a consequence, we prove — up to a few mathematical technicalities — that, fixed an integer N , the number of monster potentials with N roots coincides with the number of integer partitions of N , which is the dimension of the level N subspace of the quantum KdV model. In striking accordance with the ODE/IM correspondence.


1977 ◽  
Vol 32 (12) ◽  
pp. 1541-1543
Author(s):  
H. Sterk ◽  
J. J. Suschnigg

Abstract Attempts to the Calculation of the Chemical Shift with Especial Consideration of the Paramagnetic Term The calculation of the paramagnetic term according to the Pople formalism of the chemical shift is expanded. The hitherto constant value of the energy gap between the ground state and the excited states is replaced by the value of the lowest lying excitation. This leads to a remarkably better differentiation of the paramagnetic terms of different compounds. The influence is shown on ethane, ethene and ethine.


Sign in / Sign up

Export Citation Format

Share Document