共查询到20条相似文献,搜索用时 625 毫秒
1.
The phenomenological non-relativistic quark model (NRQM) has been employedto obtain the masses of bottomonium states. In the frame work of
NRQM an exhaustive study of radiative and leptonic decays has been made.The Hamiltonian used in the investigation has kinetic energy, confinement potential and one gluon exchange potential (OGEP). An overall agreement is obtained with the experimental masses and decay widths. 相似文献
2.
The decay properties of the D and D s mesons are computed in a nonrelativistic phenomenological quark-antiquark potential of the type V (r) =-4 3 α s r+ Ar ν with different choices of ν.Numerical method to solve the Schrdinger equation has been used to obtain the spectroscopy of qQ mesons.The numerically obtained radial solutions are employed to obtain the decay constant and leptonic decay widths.It has been observed that predictions of the ground state masses and the decay widths are consistent with other model predictions as well as with the known experimental values. 相似文献
3.
A nonrelativistic Hamiltonian with plausible spin dependent corrections is proposed for the quarkonia below their respective
strong decay thresholds. With only six free parameters this model reproduces the nine known masses of the bottomonia within
about 1 MeV, the six known masses of the charmonia within a few MeV and the five known leptonic decay widths of the states within about 20%. The model is then used to predict the masses of the remaining 43 qu arkonia (some of them for the
first time) and of the leptonic decay widths of the two states. Comparison with some other models is made.
Received: 17 June 1997 相似文献
4.
The manner in which isobaric multiplet decay widths are modified by electromagnetic interaction is studied. Arguments based on lowest-order perturbation theory are given that the widths should be quadratic in Tz, if the multiplet is particle unstable in the absence of electromagnetism, but quartic for stable multiplets. The total widths of experimentally known multiplets are analyzed to determine their algebraic Tz, dependence and both quadratic and non-quadratic cases are found. On the basis of a simple model of the Coulomb energy we then determine the masses of these multiplets in the absence of electromagnetism as well as the masses of the lowest T-allowed decay channels. We find the isobaric multiplet width equation to work in some cases while it has been found to be inconclusive in others; because of these uncertainties as to its correctness or range of applicability, we have constructed a soluble model in which tests may be carried out. To avoid difficulties such as the many-body problem, a non-local separable potential model simple enough to solve explicitly was chosen. Although the model is an oversimplification of the real nuclear situation it has been found to work very well. Namely, the quadratic quartic nature of the widths was borne out in the model. 相似文献
5.
We investigate the spectrum and decay rates of charmonium states within the framework of the non relativistic quark model by employing a Coulomb like potential from the perturbative one gluon exchange and the linear confining potential along with the potential derived from instanton vacuum to account for the hyperfine mass splitting of charmonium states in variational approach. We predict radiative E1, M1, two-photon, lepton and two-gluon decay rates of low lying charmonium states. An overall agreement is obtained with the experimental masses and decay widths.We have estimated the branching ratio of two gluons decaying into light hadrons. 相似文献
6.
《Nuclear Physics A》1999,653(3):277-300
The modifications of hadronic masses and decay widths at finite temperature and baryon density are investigated using a phenomenological model of hadronic interactions in the Relativistic Hartree Approximation. We consider an exhaustive set of hadronic reactions and vector meson decays to estimate the photon emission from hot and dense hadronic matter. The reduction in the vector meson masses and decay widths is seen to cause an enhancement in the photon production. It is observed that the effect of p-decay width on photon spectra is negligible. The effects on dilepton production from pion annihilation are also indicated. 相似文献
7.
The decay widths for the radiative decays of heavy baryons are calculated in the heavy quark effective theory. Introducing
the interpolating fields for heavy baryons we obtain the transition matrix elements and the corresponding decay widths. Considering
theSU(6) flavor-spin wave functions for heavy baryons, the coupling constants are calculated in the nonrelativistic quark model.
Since the masses of the heavy baryons are not available, we have taken the predicted bag model masses. We find our results
are quite different from that of the heavy quark bag model calculations. 相似文献
8.
Using the variational method we calculate mesonic wave function. We report masses and decay constants for heavy-light mesons. Leptonic decay widths of charmed and beauty mesons are also calculated. The obtained results are compared with the available experimental and theoretical data. 相似文献
9.
A. Djouadi Y. Mambrini M. Mühlleitner 《The European Physical Journal C - Particles and Fields》2001,20(3):563-584
We perform a comprehensive analysis of the decays of charginos and neutralinos in the minimal supersymmetric standard model
where the neutralino is assumed to be the lightest supersymmetric particle. We focus, in particular, on the three-body decays of the next-to-lightest
neutralino and the lightest chargino into the lightest neutralino and fermion–antifermion pairs and include vector boson,
Higgs boson and sfermion exchange diagrams, where in the latter contribution the full mixing in the third generation is included.
The radiative corrections to the heavy fermion and SUSY particle masses will also be taken into account. We present complete
analytical formulae for the Dalitz densities and the integrated partial decay widths in the massless fermion case, as well
as the expressions of the differential decay widths including the masses of the final fermions and the polarization of the
decaying charginos and neutralinos. We then discuss these decay modes, in particular in scenarios where the parameter is large and in models without universal gaugino masses at the grand unification scale, where some new decay channels, such
as decays into gluinos and pairs, open up.
Received: 12 April 2001 / Published online: 8 June 2001 相似文献
10.
Excited state mass spectra,decay properties and Regge trajectories of charm and charm-strange mesons
The framework of a phenomenological quark-antiquark potential(Coulomb plus linear confinement)model with a Gaussian wave function is used for detailed study of masses of the ground, orbitally and radially excited states of heavy-light Qq,(Q=c,q=u/d,s) mesons. We incorporate a O(1/m) correction to the potential energy term and relativistic corrections to the kinetic energy term of the Hamiltonian. The spin-hyperfine, spin-orbit and tensor interactions incorporating the effect of mixing are employed to obtain the pseudoscalar, vector, radially and orbitally excited state meson masses. The Regge trajectories in the(J,M~2) and(nr,M~2) planes for heavy-light mesons are investigated with their corresponding parameters. Leptonic and radiative leptonic decay widths and corresponding branching ratios are computed. The mixing parameters are also estimated. Our predictions are in good agreement with experimental results as well as lattice and other theoretical models. 相似文献
11.
Physics of Atomic Nuclei - A new relativistic semiclassical expression is derived for leptonic decay widths of vector mesons as a composite system of two quarks having equal masses and interacting... 相似文献
12.
The di-gamma and di-gluon decay widths of P-wave cc mesons are computed in nonrelativistic phenomenological quark-antiquark potential of the type V (r) =-4 3 α s r+ Ar ν with different choices of ν using spectroscopic parameters.The numerically obtained radial solutions are employed to obtain the di-gamma and di-gluon decay widths.The computed decay widths are consistent with other model predictions as well as with the known experimental values in the range of potential index 0.7 ≤ν≤ 1.1. 相似文献
13.
Jürgen Baacke Yuji Igarashi Gerhard Kasperidus 《Zeitschrift fur Physik C Particles and Fields》1982,13(2):131-137
We present a phenomenological analysis of a self-consistent (fixed) bag approach to heavyQ \(\bar Q\) bags developed previously by us. The scheme includes all first order relativistic corrections consistently. The agreement of our results with the experimentally observed masses and decay widths is of the same quality as in potential models. 相似文献
14.
Based on the large rate of radiative Z decays, estimates for production and subsequent γ decay of possible narrow scalar or vector resonances are derived for e+e? colliders. From this, also model-independent lower bounds on their total production rates can be deduced. γγ experiments could set stringent limits on masses and widths of (pseudo) scalar states. 相似文献
15.
M. Zieliński 《Zeitschrift fur Physik C Particles and Fields》1987,34(2):255-256
I discuss constraints on properties of isoscalarJ PC =1?+ exotic hybrid mesons, assuming their dominant decay mode is ηπ. This work expands on a similar study by the Rochester-Minnesota-Fermilab collaboration, which excluded ?π as the dominant decay channel for such hybrids. The experimental limits are based on Primakoff production of such states and on a VDM argument relating their radiative widths to their ?π decay modes. Using data on coherent production of ηπ+ systems in π+ collisions with nuclei, I obtain few percent limits on the ?π branching ratios for hybrid masses ?1.5 GeV. 相似文献
16.
17.
The mass spectrum ofcb meson is investigated with an effective quark-antiquark potential of the form -αc/r +Ar
νwith ν varying from 0.5 to 2.0. TheS andP-wave masses, pseudoscalar decay constant, weak decay partial widths in spectator model and the lifetime ofB
cmeson are computed. The properties calculated here are found to be in good agreement with other theoretical and experimental
values at potential index,ν = 1 相似文献
18.
Zahra Ghalenovi 《International Journal of Theoretical Physics》2018,57(9):2628-2639
Light flavour baryons are studied in a non-relativistic potential model with colour Coulomb plus linear confinement potential using a simple variational method. The ground-state masses and magnetic moments of the light baryons are computed using a spin- and isospin-dependent potential. We extend our scheme to predict the transition magnetic moments of \(B_{(J^{P}={3/2}^{+})} \rightarrow B_{(J^{P}={1/2}^{+})}\gamma \) processes. We also compute the radiative decay widths and branching ratios of light baryons. A comparison of our results with those of other works and experimental data is also presented. 相似文献
19.
Bikash Sinha 《Pramana》2000,54(4):573-587
Successive equilibration of quark degrees of freedom and its effects on electromagnetic signals of quark gluon plasma are
discussed. The effects of the variation of vector meson masses and decay widths on photon production from hot strongly interacting
matter formed after Pb + Pb and S + Au collisions at CERN SPS energies are considered. It has been shown that the present
photon spectra measured by WA80 and WA98 Collaborations can not distinguish between the formation of quark matter and hadronic
matter in the initial state. 相似文献
20.
In the framework of relativistic harmonic confinement model for quarks and antiquarks, the masses of S- and P-wave mesons and pseudoscalar decay constants from light flavour to heavy flavour sectors are computed. The residual two-body
Coulomb interaction and the spin-dependent interaction of the confined one gluon exchange effects (COGEP) such as spin-spin
and spin-orbit interactions are perturbatively incorporated with the confinement energy to get the respective vector-pseudoscalar
meson mass differences. Here we employ the same parametrization and model parameters as used in a recent study of low-lying
hadron masses and leptonic decay widths. The results are being compared with the values obtained from other theoretical models
and the experimental values. 相似文献