A Missing Partner Model With 24-plet Breaking SU(5)

We give a missing partner model using 24-plet instead of 75-plet to break the SU(5) symmetry. Fermion masses and mixing are generated through the Georgi-Jarlskog mechanism. The model is constructed at renormalizable level at very high energy. The perturbative region is extended for the unification gauge coupling. Constrains by proton decay is also satisfied.Comment: 18 pages, 6 figure

Ising parameterization of QCD Landau free energy and its dynamics

We present a general linear parameterization scheme for the QCD Landau free energy in the vicinity of the critical point of chiral phase transition in the $\mu$-$T$ plane. Based on the parametric free energy, we show that, due to the finite size effects, the regions of fluctuations of the order parameter (i.e. the $\sigma$ field) are broadened, and the discontinuities of the first order phase transition are smoothed. Meanwhile, the kurtosis of the $\sigma$ field is universally negative around the critical point. Using the Fokker-Plank equation, we derive the dynamical corrections to the free energy. The dynamical cumulants of the $\sigma$ field on the freeze-out line, record earlier information in the first order phase transition region as compared to the crossover region. The typical behavior of dynamical cumulants can be understood from the equilibrium cumulants by considering the memory effects.Comment: 8 pages, 5 figures. Fig.1 is replaced. More discussions are adde

Superfluidity enhanced by spin-flip tunnelling in the presence of a magnetic field

It is well-known that when the magnetic field is stronger than a critical value, the spin imbalance can break the Cooper pairs of electrons and hence hinder the superconductivity in a spin-singlet channel. In a bilayer system of ultra-cold Fermi gases, however, we demonstrate that the critical value of the magnetic field at zero temperature can be significantly increased by including a spin-flip tunnelling, which opens a gap in the spin-triplet channel near the Fermi surface and hence reduces the influence of the effective magnetic field on the superfluidity. The phase transition also changes from first order to second order when the tunnelling exceeds a critical value. Considering a realistic experiment, this mechanism can be implemented by applying an intralayer Raman coupling between the spin states with a phase difference between the two layers.Comment: 10+4 pages, 8 figure

On anti-gravitational phenomenon of excited states in quantum systems

It is common belief that gravity is an attractive interaction between all things with mass or energy, affecting the motion of objects at the macroscopic scale and determining the large-scale structure of the universe. Contrary to the conventional cognition, here we reveal that gravitational repulsion is also ubiquitous in quantum systems -- the anomalous response of the position of the particles at (topologically) excited states to the gravitational field in confined systems. We prove that this anti-gravitational phenomenon results from a principle called `quantum-state exclusion' inherited from the orthogonality of quantum states. We further predict that, in an inflating space, this gravitational anomaly may cause quantum matter in excited states to expand even faster than space, leading to an observable accumulation of quantum matter near the boundary of the space. These unique phenomena can be simulated in ultracold atom experiments by using Bose-Einstein condensates with solitons. The accelerating expansion phenomenon in quantum systems also sheds new light on understanding the evolution of the universe, where the vacuum state may also be an excitation with topological defects.Comment: 7 pages, 2+2 figures (abstract and introduction are updated

Dynamically observing the spectra of quantum droplets in optical lattice

Optical lattice plays an important role on stability and dynamics of quantum droplets. In this letter, we investigate the Bogoliubov excitation spectrum of quantum droplets in optical lattice in the thermodynamic limit. We classify the collective excitations as synchronous modes, Bloch phononic modes, and site-density imbalanced modes. For synchronous modes, we measure the dipole oscillation frequencies by quench dynamics with a sudden shift of the optical lattice, and the breathing frequencies by Floquet dynamics with a periodic change of the lattice depth. Bloch phononic modes are observable from the Landau critical velocity of the droplets. We further discuss the instability induced by the site-dependent density fluctuations, and calculate the critical filling of atoms where the growth of lattice vacancy breaks down the translational symmetry of the system. This work makes essential steps towards measuring the excitation spectrum and understanding the superfluid nature of quantum droplets in optical lattice.Comment: 5 figure