arXiv subjects

V. M. Belyaev

Publications and source records attributed to V. M. Belyaev.

21 records · Page 2Linked to original sources

arXiv1993

QCD Calculation of the $B \rightarrow π,K$ Form Factors

We calculate the form factors for the heavy-to-light transitions $B\rightarrow π,K $ by means of QCD sum rules using $π$ and $K$ light-cone wave functions. Higher twist contributions as well as gluonic corrections are taken into account. The sensitivity to the shape of the leading-twist wave functions and effects of SU(3)-breaking are discussed. The results are compared with quark model predictions and with the results from QCD sum rules for three-point correlators.

hep-ph↗

arXiv1993

Soft Modes Contribution into Path Integral

A method for nonperturbative path integral calculation is proposed. Quantum mechanics as a simplest example of a quantum field theory is considered. All modes are decomposed into hard (with frequencies $ω^2 >ω^2_0$) and soft (with frequencies $ω^2 <ω^2_0$) ones, $ω_0$ is a some parameter. Hard modes contribution is considered by weak coupling expansion. A low energy effective Lagrangian for soft modes is used. In the case of soft modes we apply a strong coupling expansion. To realize this expansion a special basis in functional space of trajectories is considered. A good convergency of proposed procedure in the case of potential $V(x)=λx^4$ is demonstrated. Ground state energy of the unharmonic oscillator is calculated.

hep-ph↗

arXiv1993

Delta-Isobar Magnetic Form Factor in QCD

We consider the QCD sum rules approach for Delta-isobar magnetic form factor in the infra-red region $0<Q^2<1GeV^2$. The QCD sum rules in external variable field are used. The obtained formfactor is in agreement with quark model predictions for the Delta-isobar magnetic moment.

hep-ph↗