About me

I am a Professor of Physics at the Old Dominion University (ODU) and a Senior Staff Member of the Theory Division at Thomas Jefferson Lab National Accelerator Facility (JLab). I received my Ph.D. in Physics from Petersburg Nuclear Physics Institute (St. Petersburg, Russia) in 1984. After that I worked at PNPI, Penn State University, MIT, and from 1996 I am at ODU/JLab.

My main sphere of interest is Quantum Chromodynamics (QCD). I have around 100 papers published in leading Physics Journals with the total number of citations over 10000. My two favorite results are the BFKL pomeron in QCD and the BK equation for the evolution of color dipoles.


Professional Interests

There are two reasons why the Theory of High-Energy Scattering in Quantum Chromodynamics (QCD) is still interesting thirty years after its creation. First, the information about the fundamental structure of matter comes from experiments performed at high-energy accelerators such as the new Large Hadron Collider (LHC). To search for a New Physics at LHC one needs to separate the signal (creation of a new particle) from the background (emission of several hundred of `old' particles) which sould be described by QCD with sufficient accuracy. Second, there are accelerators that probe the structure of QCD matter both in normal circumstances (Jefferson Lab) and under extreme conditions which may have existed at the Beginning of the Universe (studies of quark-gluon plasma at RHIC accelerator at Brookhaven National Laboratory).

My main interest at the moment is the study of the high-energy behavior in high-density QCD. The most studied case is the Deep Inelastic Scattering (DIS) at small values of Bjorken variable x. The small-x behavior of DIS structure functions is described by the evolution of color dipoles. In the leading order it is given by the Balitsky-Kovchegov (BK) equation which is now a starting point of discussion of the small-x evolution in the saturation regime. The BK equation is an asymptotic one, and in order to find whether it is relevant at present energies one needs to know the next-to-leading order (NLO) corrections. This was the long-standing problem in the Saturation Physics, and after a year of calculations my student G. Chirlilli and I we were able to solve it. Careful analysis of the NLO corrections is very important from both theoretical and experimental points of view since it determines whether the description of DIS in terms of color dipoles may be useful for the future Electron-Ion Collider.

Another process which is somewhat less understood theoretically is the heavy-ion scattering studied at RHIC and LHC. Unlike the DIS which can be interpreted (in the lab-frame) as a creation of dipoles by virtual photon with subsequent scattering of these dipoles from the nucleus, the scattering of two heavy nuclei should involve the evolution going both ways to any of the nuclei. It appears that the only hope for the analytical calculation in QCD is to construct a 2+1 effective action (with time = rapidity) which incorporates the two evolutions. Such an effective action would include both creation and annihilation of the dipoles and hence admit the pomeron loops which are arguably the source of the unitarization of high-energy amplitudes. If obtained, such high-energy effective action would describe the scattering of heavy ions in QCD which up to now has been investigated only by numerical simulations. In my recent papers I suggested a new approach to the high-energy effective action based on the rapidity factorization. Within this framework, the effective action is determined by the amplitude of scattering of shock waves in QCD and in next few years I intend to pursue studies in this direction.