  A generically observed mechanism that drives the self-organization of living
systems is interaction via chemical signals among the individual elements --
which may represent cells, bacteria, or even enzymes. Here we propose a novel
mechanism for such interactions, in the context of chemotaxis, which originates
from the polarity of the particles and which generalizes the well-known
Keller--Segel interaction term. We study the resulting large-scale dynamical
properties of a system of such chemotactic particles using the exact stochastic
formulation of Dean and Kawasaki along with dynamical renormalization group
analysis of the critical state of the system. At this critical point, an
emergent "Galilean" symmetry is identified, which allows us to obtain the
dynamical scaling exponents exactly; these exponents reveal superdiffusive
density fluctuations and non-Poissonian number fluctuations. We expect our
results to shed light on how molecular regulation of chemotactic circuits can
determine large-scale behavior of cell colonies and tissues.
