6599022
LEPTONIC AND SEMILEPTONIC DECAYS OF PSEUDOSCALAR MESONS
Abstract We employ the relativistic constituent quark model to give a unified description of the leptonic and semileptonic decays of pseudoscalar mesons ( π , K , D , D s , B , B s ). The calculated leptonic decay constants and form factors are found to be in good agreement with available experimental data and other approaches. We reproduce the results of spin-flavor symmetry in the heavy quark limit.
995629
The Semileptonic decays of the $B_c$ meson
We study the semileptonic transitionsBc → �c, J/ , D, D ∗ , B, B ∗ , Bs, B ∗ s in the framework of a relativistic constituent quark model. We use experimental data on leptonic J/ decay, lattice and QCD sum rule results on leptonic Bc decay, and experimental data on radiativec transitions to adjust the quark model parameters. We compute all form factors of the above semileptonic Bc-transitions and give predictions for various semileptonic Bc decay modes including their �-modes when they are kinematically accessible. The impli- cations of heavy quark symmetry for the semileptonic decays are discussed and are shown to be manifest in our explicit relativistic quark model calcu- lation. A comparison of our results with the results of other calculations is performed.
121608979
Heavy baryons in the relativistic quark model
Abstract We present a summary of results for exclusive decays of single and double heavy-flavored baryons in the relativistic three-quark model.
119335036
Exclusive semileptonic and nonleptonic decays of the B c meson
We study exclusive nonleptonic and semileptonic decays of the B{sub c}-meson within a relativistic constituent quark model previously developed by us. For the nonleptonic decays we use the factorizing approximation. We update our model parameters by using new experimental data for the mass and the lifetime of the B{sub c} meson and the leptonic decay constants of the D-meson. We calculate the branching ratios for a large set of exclusive nonleptonic and semileptonic decays of the B{sub c} meson and compare our results with the results of other studies. As a guide for further experimental exploration we provide explicit formulas for the full angular decay distributions in the cascade decays B{sub c}{sup -}{yields}J/{psi}({yields}l{sup +}l{sup -})+{rho}{sup -}({yields}{pi}{sup -}{pi}{sup 0}) and B{sub c}{sup -}{yields}J/{psi}({yields}l{sup +}l{sup -})+W{sub off-shell}{sup -}({yields}l{sup -}+{nu}{sub l})
117870749
On the mesonic Lagrangian of order p^6 in chiral SU(2)
We show that the number of operators in the presently known mesonic chiral Lagrangian of order p^6 in the two-flavour sector can be reduced by at least one from 57 to 56 by providing an explicit relation among the operators. We briefly discuss the relevance of this new relation.
198488906
The Box anomaly and radiative decays of eta(eta-prime) mesons
We report on a confined quark model calculation of the transition form factors for the radiative decays of \eta(\eta')->\gamma l^+l^- and \eta(\eta')->\gamma\pi^+\pi^-. The \eta-\eta' mixing angle \theta_P is determined from the set of data on the electromagnetic \eta(\eta') decays. It is found that \theta_P\sim -16.5. The analysis of the dipionic mass distribution in the decay \eta'->\gamma\pi^+\pi^- confirms the existence of a non-resonant contribution which is the box anomaly.
8984328
The graviton background: a new way to quantum gravity
Graviton pairing and destruction of these pairs under collisions with bodies may lead to the Newtonian attraction. It opens us a new way to a very-low-energy quantum gravity model. In the model by the author, cosmological redshifts are caused by interactions of photons with gravitons of the background. Non-forehead collisions with gravitons lead to an additional relaxation of any photonic flux. Total galaxy number counts/redshift and galaxy number counts/magnitude relations are computed and found to be in a good agreement with galaxy observations.
56021013
Another possible interplay between gravitation and cosmology
I describe here some features of a non-geometrical approach to quantum gravity which leads to another picture of ties of gravitation and cosmology. The role of taking into account the effect of time dilation of the standard cosmological model is considered. It is shown that the correction for no time dilation leads to a good accordance of Supernovae 1a data and predictions of the considered model. The distributions of stretch factor values of Supernovae 1a for the cases of time dilation and no time dilation are discussed.
18218791
Non-Dopplerian cosmological redshift parameters in a model of graviton-dusty universe
Possible effects, which could be caused by a hypothetical super-strong interaction of photons or massive bodies with single gravitons of the graviton background, are considered. If full cosmological redshift magnitudes are caused by the interaction, then the luminosity distance in a flat non-expanding universe as a function of redshift is very similar to the specific function which fits supernova cosmology data by Riess et al (1998 Astron. J. 116 1009). From another side, in this case every massive body, moving slowly relative to the background, would experience a constant acceleration, proportional to the Hubble constant, of the same order as a small additional acceleration of Pioneer 10, 11.
15370571
Gravitons as super-strong interacting particles, and low-energy quantum gravity
It is shown by the author that if gravitons are super-strong interacting particles and the low-temperature graviton background exists, the basic cosmological conjecture about the Dopplerian nature of redshifts may be false. In this case, a full magnitude of cosmological redshift would be caused by interactions of photons with gravitons. A new dimensional constant which characterizes one act of interaction is introduced and estimated. Non-forehead collisions with gravitons will lead to a very specific additional relaxation of any photonic flux. It gives a possibility of another interpretation of supernovae 1a data - without any kinematics. Of course, all of these facts may implicate a necessity to change the standard cosmological paradigm. Some features of a new paradigm are discussed here, too. A quantum mechanism of classical gravity based on an existence of this sea of gravitons is described for the Newtonian limit. This mechanism needs graviton pairing and "an atomic structure" of matter for working it, and leads to the time asymmetry. If the considered quantum mechanism of classical gravity is realized in the nature, than an existence of black holes contradicts to Einstein's equivalence principle. It is shown that in this approach the two fundamental constants - Hubble's and Newton's ones - should be connected between themselves. The theoretical value of the Hubble constant is computed. In this approach, every massive body would be decelerated due to collisions with gravitons that may be connected with the Pioneer 10 anomaly. It is shown that the predicted and observed values of deceleration are in good agreement. Some unsolved problems are discussed, so as possibilities to verify some conjectures in laser-based experiments.
14365154
Lorentz symmetry violation due to interactions of photons with the graviton background
The average time delay of photons due to multiple interactions with gravitons of the background is computed in a frame of the model of low-energy quantum gravity by the author. The two variants of evaluation of the lifetime of a virtual photon are considered: 1$)$ on a basis of the uncertainties relation (it is a common place in physics of particles) and 2$)$ using a conjecture about constancy of the proper lifetime of a virtual photon. It is shown that in the first case Lorentz violation is negligible: the ratio of the average time delay of photons to their propagation time is equal approximately to $10^{-28}$; in the second one (with a new free parameter of the model), the time-lag is proportional to the difference $\sqrt{E_{01}}-\sqrt{E_{02}}$, where $E_{01}, E_{02}$ are initial energies of photons, and more energetic photons should arrive later, also as in the first case. The effect of graviton pairing is taken into account, too.