# M. V. Bondarenco

## Publications Authored By M. V. Bondarenco

Existence of different types of interference in the spectrum of radiation emitted by a doubly hard scattered electron is demonstrated. The spectrum develops oscillations in two regions: the hard, where the oscillations depend on the electron Lorentz factor, and the soft, where the oscillations depend on the electron scattering angles. This interference pattern owes to the presence of jetlike radiation configurations, formed by a piecewise-rectilinearly moving electron and the accompanying photon. Read More

Evaluation of the angular distribution function of particles scattered in an amorphous medium is improved by deforming the integration path in the Fourier integral representation into the complex plane. That allows us to present the distribution function as a sum of two positive components, soft and hard, the soft component being close to a Gaussian, and the hard component vanishing in the forward direction, while including the Rutherford asymptotics and all the power corrections to it at large scattering angles. Detailed properties of those components, and their interplay at intermediate deflection angles are discussed. Read More

Recent results in the theory of multiphoton spectra for coherent radiation sources are overviewed, with the emphasis on channeling radiation. For the latter case, the importance of the order of resummation and averaging is illustrated. Limiting shapes of multiphoton spectra at high intensity are discussed for different channeling regimes. Read More

We investigate the interference pattern in the spectrum of non-dipole bremsstrahlung on two amorphous foils. Apart from suppression at lowest $\omega$, the spectrum exhibits an enhancement adjacent to it. In classical electrodynamics, the net effect of suppression and enhancement proves to be zero. Read More

At measurements of gamma-radiation spectra from ultra-relativistic electrons in periodic structures, pileup of events in the calorimeter may cause significant deviation of the detector signal from the classically evaluated spectrum. That requires appropriate resummation of multiphoton contributions. We describe the resummation procedure for the photon spectral intensity and for the photon multiplicity spectrum, and apply it to the study of spectra of coherent radiation with an admixture of incoherent component. Read More

We propose a simple parameterization for $q_T$-spectrum of inclusive $Z$-boson production, and test it against world collider data at different energies. The fit gives good agreement with the data, and indicates the existence of two distinguishable breaks in the $q_T$-spectrum. Energy dependences of the fitted parameters are discussed. Read More

It is argued that $W/Z$ boson production in ultra-relativistic $pp$ collisions in the fragmentation region, subject to a kinematic cut on the boson transverse momentum $Q_\perp>Q_{\perp\min}$, with 1 GeV/c$\ll Q_{\perp\min}\ll M_{W/Z}$, must be dominated by the Compton mechanism $qg\to q'W/Z$. We propose applications for boson hadroproduction in this kinematics and formulate the factorization theorem. The analysis of QCD enhancements indicates that Regge behavior should manifest itself not only in the $s$ but also in $Q_\perp$-dependence of the boson production differential cross-section. Read More

For a particle traversing a bent crystal in the regime of volume reflection we evaluate the probability of interaction with atomic nuclei. Regardless of the continuous potential shape, this probability is found to differ from the corresponding value in an amorphous target by an amount proportional to the crystal bending radius, and the particle deflection angle. Based on this result, we evaluate the rate of inelastic nuclear interactions, and the final beam angular dispersion due to multiple Coulomb scattering. Read More

Recent theoretical results on charged particle interaction with planarly oriented thin bent crystals are reviewed, with the emphasis on dynamics in the continuous potential. Influence of boundary conditions on the volume-reflected beam profile is discussed. Basic properties of coherent bremsstrahlung in a bent crystal are highlighted. Read More

It is shown that for a constituent quark in the intra-nucleon self-consistent field the spin-orbit interaction lowers the quark rest energy to values $\sim100$ MeV, which agrees with the DIS momentum sum rule. The possibility of violation of the spectral condition for the light-cone momentum component of a bound quark is discussed. Read More

For volume reflection process in a bent crystal, exact analytic expressions for positively- and negatively-charged particle trajectories are obtained within a model of parabolic continuous potential in each interplanar interval, with the neglect of incoherent multiple scattering. In the limit of the crystal bending radius greatly exceeding the critical value, asymptotic formulas are obtained for the particle mean deflection angle in units of Lindhard's critical angle, and for the final beam profile. Volume reflection of negatively charged particles is shown to contain effects of rainbow scattering and orbiting, whereas with positively charged particles none of these effects arise within the given model. Read More

Radiation spectrum from high energy $e^\pm$ in a bent crystal with arbitrary curvature distribution along the longitudinal coordinate is evaluated, based on the stationary phase approximation. For a uniformly bent crystal a closed-form expression for the spectrum is derived. Features such as sharp end of spectrum and volume reflection turnover at beginning of the spectrum are discussed. Read More

Bremsstrahlung from relativistic electrons is considered under conditions when some transverse direction of momentum transfer is statistically preferred. It is shown that in the dipole approximation all the medium anisotropy effects can be accumulated into a special modulus-bound transverse vector, $\bm N$. To exemplify a target with $N^2\sim1$, we calculate radiation from electron incident at a small angle on an atomic row in oriented crystal. Read More

The Kirschner-Lipatov result for the DLLA of high-energy $qq'$ backward scattering is re-derived without the use of integral equations. It is shown that part of the inequalities between the variables in the logarithmically-divergent integrals is inconsequential. The light-cone wave-function interpretation under the conditions of backward scattering is discussed. Read More

The 2-quark back-angle scattering mechanism is shown to reproduce main features of high-energy $hh$ flavor-exchange reactions. Prospects for reduction of the reaction matrix element to a form of convolution of hadron wave functions with the hard scattering kernel are discussed. Wave function models suitable for convolution with the kernel, which is singular at small $x$, and the emerging form-factor types, are discussed. Read More

An economic technique for calculation of polarized bremsstrahlung process is proposed, assuming typical atomic momentum transfer $q\ll m$. The adopted approach is based on the natural reduction of the matrix element to the form $V^{\alpha}\gamma^{\alpha}+A_{5}\gamma ^{5}$. Polarization distribution in the fully differential cross-section is analyzed. Read More