424,019 research outputs found
Catalysis of Dynamical Chiral Symmetry Breaking by Chiral Chemical Potential in Dirac semimetals
In this paper we study how dynamical chiral symmetry breaking is affected by
nonzero chiral chemical potential in Dirac semimetals. To perform this study we
applied lattice quantum Monte Carlo simulations of Dirac semimetals. Within
lattice simulation we calculated the chiral condensate for various fermion
masses, the chiral chemical potentials and effective coupling constants. For
all parameters under consideration we have found that the chiral condensate is
enhanced by chiral chemical potential. Thus our results confirms that in Dirac
semimetals the chiral chemical potential plays a role of the catalyst of the
dynamical chiral symmetry breaking.Comment: 11 pages, 3 figure
Chiral Ionic Liquids: Synthesis, Properties, and Enantiomeric Recognition
We have synthesized a series of structurally novel chiral ionic liquids which have a either chiral cation, chiral anion, or both. Cations are an imidazolium group, while anions are based on a borate ion with spiral structure and chiral substituents. Both (or all) stereoisomeric forms of each compound in the series can be readily synthesized in optically pure form by a simple one-step process from commercially available reagents. In addition to the ease of preparation, most of the chiral ILs in this series are liquid at room temperature with a solid to liquid transformation temperature as low as −70 °C and have relatively high thermal stability (up to at least 300 °C). Circular dichroism and X-ray crystallographic results confirm that the reaction to form the chiral spiral borate anion is stereospecific, namely, only one of two possible spiral stereoisomers was formed. Results of NMR studies including 1H{15N} heteronuclear single quantum coherence (HSQC) show that these chiral ILs exhibit intramolecular as well as intermolecular enantiomeric recognition. Intramolecularly, the chiral anion of an IL was found to exhibit chiral recognition toward the cation. Specifically, for a chiral IL composing with a chiral anion and a racemic cation, enantiomeric recognition of the chiral anion toward both enantiomers of the cation lead to pronounced differences in the NMR bands of the cation enantiomers. The chiral recognition was found to be dependent on solvent dielectric constant, concentration, and structure of the ILs. Stronger enantiomeric recognition was found in solvent with relatively lower dielectric constants (CDCl3 compared to CD3CN) and at higher concentration of ILs. Also, stronger chiral recognition was found for anions with a relatively larger substituent group (e.g., chiral anion with a phenylmethyl group exhibits stronger chiral recognition compared to that with a phenyl group, and an anion with an isobutyl group has the weakest chiral recognition). Chiral anions were also found to exhibit intermolecular chiral recognition. Enantiomeric discrimination was found for a chiral IL composed of a chiral anion and achiral cation toward another chiral molecule such as a quinine derivative
Thermal chiral vortical and magnetic waves: new excitation modes in chiral fluids
In certain circumstances, chiral (parity-violating) medium can be described
hydrodynamically as a chiral fluid with microscopic quantum anomalies. Possible
examples of such systems include strongly coupled quark-gluon plasma, liquid
helium 3He-A, neutron stars and the Early Universe. We study first-order
hydrodynamics of a chiral fluid on a vortex background and in an external
magnetic field. We show that there are two previously undiscovered modes
describing heat waves propagating along the vortex and magnetic field. We call
them the Thermal Chiral Vortical Wave and Thermal Chiral Magnetic Wave. We also
identify known gapless excitations of density (chiral vortical and chiral
magnetic waves) and transverse velocity (chiral Alfven wave). We demonstrate
that the velocity of the chiral vortical wave is zero, when the full
hydrodynamic framework is applied, and hence the wave is absent and the
excitation reduces to the charge diffusion mode. We also comment on the
frame-dependent contributions to the obtained propagation velocities.Comment: 5 pages. Version to appear in Nucl. Phys.
Partition Function of Chiral Boson on 2-Torus from Floreanini-Jackiw Lagrangian
We revisit the problem of quantizing a chiral boson on a torus. The
conventional approach is to extract the partition function of a chiral boson
from the path integral of a non-chiral boson. Instead we compute it directly
from the chiral boson Lagrangian of Floreanini and Jackiw modified by
topological terms involving auxiliary fields. A careful analysis of the
gauge-fixing condition for the extra gauge symmetry reproduces the correct
results for the free chiral boson, and has the advantage of being applicable to
a wider class of interacting chiral boson theories.Comment: 31 pages, minor modificatio
Chiral and Critical Behavior in Strong Coupling QCD
We use a cluster algorithm to study the critical behavior of strongly coupled
lattice QCD in the chiral limit. We show that the finite temperature chiral
phase transition belongs to the O(2) universality class as expected. When we
compute the finite size effects of the chiral susceptibility in the low
temperature phase close to the transition, we find clear evidence for chiral
singularities predicted by chiral perturbation theory (ChPT). On the other hand
it is difficult to reconcile the quark mass dependence of various quantities
near the chiral limit with ChPT.Comment: 3 Pages, 3 figures, Lattice2003(nonzero
New quantum effects in relativistic magnetohydrodynamics
Chiral anomaly induces a new kind of macroscopic quantum behavior in
relativistic magnetohydrodynamics, including the chiral magnetic effect. In
this talk we present two new quantum effects present in fluids that contain
charged chiral fermions: 1) the turbulent inverse cascade driven by the chiral
anomaly; 2) quantized chiral magnetic current induced by the reconnections of
magnetic flux. We also discuss the implications for the evolution of the
quark-gluon plasma produced in heavy ion collisions.Comment: 4 pages, 3 figures. Talk given at Quark Matter 2017 conference,
Chicago, IL; to appear in the proceeding
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