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Alexander Andrianov

Publications and source records attributed to Alexander Andrianov.

5 recordsLinked to original sources
arXiv2020

Vector mesons spectrum in a medium with a chiral imbalance induced by the vacuum of fermions

The properties of the light vector mesons in the presence of local parity breaking medium with a chiral imbalance are considered in the vector-meson dominance model. Applying the finite lowest-order radiatively induced local effective Lagrangian, initially developed for the QED, for the vector $ρ$ and $ω$ mesons, we obtained the mass spectrum as a function of momentum and chiral chemical potential $μ_5$. We showed that in addition to the Chern-Simons term, splitting the transverse polarisations of the mesons, there is another radiatively induced contribution that becomes important at momentum and $μ_5$ around a few hundred MeV.

hep-ph↗
arXiv2018

2+1-dimensional gravity coupled to a dust shell: quantization in terms of global phase space variables

We perform canonical analysis of a model in which gravity is coupled to a spherically symmetric dust shell in 2+1 spacetime dimensions. The result is a reduced action depending on a finite number of degrees of freedom. The emphasis is made on finding canonical variables providing the global chart for the entire phase space of the model. It turns out that all the distinct pieces of momentum space could be assembled into a single manifold which has ADS^{2}-geometry, and the global chart for it is provided by the Euler angles. This results in both non-commutativity and discreteness in coordinate space, which allows to resolve the central singularity. We also find the map between ADS^{2} momentum space obtained here and momentum space in Kuchar variables, which could be helpful in extending the present results to 3+1 dimensions.

gr-qc↗
arXiv2010

Abnormal dilepton yield from parity breaking in dense nuclear matter

At finite density parity can be spontaneously broken in strong interactions with far reaching implications. In particular, a time-dependent pseudoscalar background would modify QED by adding a Chern-Simons term to the lagrangian. As a striking consequence we propose a novel explanation for the dilepton excess observed in heavy ion collisions at low invariant masses. The presence of local parity breaking due to a time-dependent pseudoscalar condensate substantially modifies the dispersion relation of photons and vector mesons propagating in such a medium, changing the $ρ$ spectral function and resulting in a potentially large excess of dileptons with respect to the predictions based in a `cocktail' of known processes.

hep-ph↗
arXiv2010

Abnormal dilepton yield from local parity breaking in heavy-ion collisions

We propose a novel explanation for the dilepton excess observed in heavy ion collisions at invariant masses below 1 GeV. We argue that the presence of local parity breaking due to a time-dependent isosinglet and/or isotriplet pseudoscalar condensate substantially modifies the dispersion relation of photons and vector mesons propagating in such a medium, changing the ρ~ spectral function and resulting in a potentially large excess of e+e- and μ+μ- with respect to the theoretical predictions based in a 'cocktail' of known hadronic processes. Possible signatures to prove or disprove this effect are discussed.

hep-ph↗