scholarly journals The decay τ → K∗0(892)K−ντ in the extended NJL model

2020 ◽  
Vol 35 (06) ◽  
pp. 2050035 ◽  
Author(s):  
M. K. Volkov ◽  
A. A. Pivovarov ◽  
K. Nurlan

In the extended Nambu–Jona-Lasinio model, the branching fraction of [Formula: see text] is calculated. The contributions from the contact diagram and the diagrams with intermediate axial-vector, vector and pseudoscalar mesons in the ground and first radially excited states are taken into account. It is shown that an axial-vector and vector channel with a contact diagram give a dominant contribution to the branching fraction. The obtained results for the branching fraction [Formula: see text] are in satisfactory agreement with experimental data. A prediction for the differential distribution over the invariant mass of the meson pair [Formula: see text] is given.

2009 ◽  
Vol 24 (13) ◽  
pp. 2415-2430 ◽  
Author(s):  
B. A. ARBUZOV ◽  
M. K. VOLKOV ◽  
I. V. ZAITSEV

In previous works effective nonlocal SU (2)× SU (2) NJL model was proposed in which all the parameters are expressed through those of the fundamental QCD: current light quark mass m0 and average nonperturbative αs. The results for scalar and pseudoscalar mesons are in satisfactory correspondence to existing data. In the present work the same model without introduction of any additional parameters is applied for a description of masses and strong decay widths of ρ- and a1-mesons. The results for both scalar and vector sectors agree with data up to accuracy of the model.


2014 ◽  
Vol 29 (24) ◽  
pp. 1450125 ◽  
Author(s):  
A. V. Vishneva ◽  
M. K. Volkov

The first radial excitations of axial-vector mesons are considered in the framework of the extended U(3) × U(3) Nambu–Jona-Lasinio model. We calculate the mass spectrum of a1, f1 and also strange axial-vector mesons. For description of radially excited states, we used the form factors of polynomial type of the second order in transverse quark momentum. For the ground- and excited-state mesons consisting of light quarks we have calculated the widths of a number of strong and radiative decays. We got satisfactory agreement with experimental data for the ground states. A set of predictions for the excited states of mesons is given.


2018 ◽  
Vol 178 ◽  
pp. 02023
Author(s):  
G.X. Zhang ◽  
H. Watanabe ◽  
F.G. Kondev ◽  
G.J. Lane ◽  
P.H. Regan ◽  
...  

This contribution will report on the experimental work on the level structure of 168Dy. The experimental data have been taken as part of the EURICA decay spectroscopy campaign at RIBF, RIKEN in November 2014. In the experiment, a 238U primary beam is accelerated up to 345 MeV/u with an average intensity of 12 pnA. The nuclei of interest are produced by in-flight fission of 238U impinging on Be target with a thickness of 5 mm. The excited states of 168Dy have been populated through the decay from a newly identified isomeric state and via the β decay from 168Tb. In this contribution, scientific motivations, experimental procedure and some preliminary results for this study are presented.


1989 ◽  
Vol 67 (12) ◽  
pp. 2178-2187 ◽  
Author(s):  
Peter S. Martin ◽  
Keith Yates ◽  
Imre G. Csizmadia

RHF SCF 3-21G calculations are reported for the 1Σg+, 1A1, 3A′, and 1,3A″ states of simple substituted acetylenes (Y—C≡C—H, where Y = H, F, Cl,CH3, andCF3), the 1A1, 1A′, and 1.3A″ states of their Markovnikov (M) vinyl cations (Y—C+ = CH2), the 1A′ and 1.3A″ states of their anti-Markovnikov (aM) vinyl cations (YCH=C+H), and the corresponding hydrated vinyl cations. Equilibrium electronic structures and the mechanism of adiabatic protonation are described qualitatively via Lewis/resonance schematic representations of the species involved. Calculated proton affinities (PA) suggest that relative to ground state Y—C≡C—H (1Σ+/1A1), Y—C≡C—H* (1.3A″) is of greatly enhanced basicity with respect to protonation of both regiocenters. A graphical representation of the ordered pairs PA(M) versus PA(aM) as a function of substituent Y and electronic state, leads to the conclusions: (1) irrespective of both regiocenter (M/aM) and state (1Σ1+/1A1, 3A, 1.3A″) the PA's for Y—C≡C—H decrease in the order CH3 > H > Cl> F > CF3; (2) in proceeding from CH3C≡CH to CF3C≡CH, a change in protonation regiospecificity (M → aM) is experienced to approximately the same extent for both S0 and S1; (3) T2 exhibits no significant protonation regioselectivity. Critical comparison of the calculated results is made with available experimental data. An approximate picture of the energy profiles for the adiabatic hydrations of Y—C≡C—H via its ground, triplet and singlet states has been developed, based on the fixed points acetylene, vinyl cation and hydrated vinyl cation. Predicted relative reactivities of these three states are in excellent accord with available experimental data on rates of hydration. Keywords: excited states, proton transfer, photohydration.


Author(s):  
А.А. Семакова ◽  
В.В. Романов ◽  
Н.Л. Баженов ◽  
К.Д. Мынбаев ◽  
К.Д. Моисеев

The results of a study of the electroluminescence of the asymmetric InAs/InAs1−ySby/InAsSbP LED heterostructures with a molar fraction of InSb in the ternary solid solution in the active region y=0.15 and y=0.16 in the temperature range 4.2−300 K are presented. Based on the experimental data, the formation of a staggered type II heterojunction at the InAs1−ySby/InAsSbP heterointerface was determined. The dominant contribution of the interface radiative transitions at the type II heterointerface in the temperature range 4.2−180 K was shown, which makes it possible to minimize the temperature dependence of the operating wavelength of the LEDs.


1990 ◽  
Vol 05 (30) ◽  
pp. 2537-2542 ◽  
Author(s):  
M. RAJASEKARAN ◽  
N. MEENAKUMARI ◽  
V. DEVANATHAN

Incorporating the effects of spin and isospin degrees of freedom in the MIT bag model, the masses of the ground and excited states of baryons are investigated in the framework of a statistical theory. The results are found to agree reasonably well with the experimental data.


2006 ◽  
Vol 21 (31n33) ◽  
pp. 2403-2409
Author(s):  
Yoshiko Kanada-En'yo

Structures of excited states in 11 C and 11 B were studied based on variational calculations after spin-parity projection in a framework of antisymmetrized molecular dynamics (AMD). The calculations systematically reproduce experimental data of the transition strengths such as Gamov-Teller(GT) and M1 transitions. A well-developed cluster structure of 2α+3 He (t) was found in the [Formula: see text] state of 11 C (11 B ). We assigned this state to the observed [Formula: see text] state at 8 MeV. The calculations reproduce the small [Formula: see text] which has been measured in the recent experiments. It was found that the [Formula: see text] state has a dilute cluster state, and its features are similar to those of the [Formula: see text] which is considered to be a gas state of three α clusters.


2015 ◽  
Vol 24 (04) ◽  
pp. 1550030 ◽  
Author(s):  
Hluf Negash ◽  
Shashank Bhatnagar

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.


2005 ◽  
Vol 70 (6) ◽  
pp. 811-825 ◽  
Author(s):  
Monika Musiał ◽  
Leszek Meissner

Our recently developed intermediate Hamiltonian Fock-space coupled-cluster (FS-CC) method with singles and doubles is applied to calculation of equilibrium geometries, harmonic frequencies and adiabatic excitation energies for some excited states of N2 and CO. Due to the intermediate Hamiltonian formulation, which provides a robust computational scheme for solving the FS-CC equations, and the efficient factorization strategy, relatively large basis sets and reference spaces are employed permitting a comparison of calculated properties with experimental data.


2009 ◽  
Vol 24 (31) ◽  
pp. 5845-5860 ◽  
Author(s):  
K. AZIZI ◽  
R. KHOSRAVI ◽  
F. FALAHATI

Using the factorization approach and considering the contributions of the current–current, QCD penguin and electroweak penguin operators at the leading approximation, the decay amplitudes and decay widths of [Formula: see text] and [Formula: see text] transitions, where q = u, d, s and P and V are pseudoscalar and vector mesons, are calculated in terms of the transition form factors of the Bq→Dq and [Formula: see text]. Having computed those form factors in three-point QCD sum rules, the branching fraction for these decays are also evaluated. A comparison of our results with the predictions of the perturbative QCD as well as the existing experimental data is presented.


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