Baryon states with open beauty in the extended local hidden gauge approach

In this paper we examine the interaction of \bar B N, \bar B \Delta, \bar B^* N and \bar B^* \Delta states, together with their coupled channels, using a mapping from the light meson sector. The assumption that the heavy quarks act as spectators at the quark level automatically leads us to the results of the heavy quark spin symmetry for pion exchange and reproduces the results of the Weinberg Tomozawa term, coming from light vector exchanges in the extended local hidden gauge approach. With this dynamics we look for states dynamically generated from the interaction and find two states with nearly zero width, which we associate to the \Lambda_b(5912) and \Lambda_b(5920) states. The states couple mostly to \bar B^* N, which are degenerate with the Weinberg Tomozawa interaction. The difference of masses between these two states, with J=1/2, 3/2 respectively, is due to pion exchange connecting these states to intermediate \bar B N states. In addition to these two \Lambda_b states, we find three more states with I=0, one of them nearly degenerate in two states of J=1/2,3/2. Furthermore we also find eight more states in $I=1$, two of them degenerate in J=1/2, 3/2, and other two degenerate in J=1/2, 3/2, 5/2.Comment: 26 pages, 9 figures, 24 table

Interacting Dirac fermions under spatially alternating pseudo-magnetic field: Realization of spontaneous quantum Hall effect

Both topological crystalline insulators surfaces and graphene host multi-valley massless Dirac fermions which are not pinned to a high-symmetry point of the Brillouin zone. Strain couples to the low-energy electrons as a time-reversal invariant gauge field, leading to the formation of pseudo-Landau levels (PLL). Here we study periodic pseudo-magnetic fields originating from strain superlattices. We study the low-energy Dirac PLL spectrum induced by the strain superlattice and analyze the effect of various polarized states. Through self-consistent Hartree-Fock calculations we establish that, due to the strain superlattice and PLL electronic structure, a valley-ordered state spontaneously breaking time-reversal and realizing a quantum Hall phase is favored, while others are suppressed.Comment: 13 pages + 2 appendices, 9 figure

Non-mechanical optical path switching and its application to dual beam spectroscopy including gas filter correlation radiometry

A non-mechanical optical switch is developed for alternately switching a monochromatic or quasi-monochromatic light beam along two optical paths. A polarizer polarizes light into a single, e.g., vertical component which is then rapidly modulated into vertical and horizontal components by a polarization modulator. A polarization beam splitter then reflects one of these components along one path and transmits the other along the second path. In the specific application of gas filter correlation radiometry, one path is directed through a vacuum cell and one path is directed through a gas correlation cell containing a desired gas. Reflecting mirrors cause these two paths to intersect at a second polarization beam splitter which reflects one component and transmits the other to recombine them into a polarization modulated beam which can be detected by an appropriate single sensor

Baryon states with open charm in the extended local hidden gauge approach

In this paper we examine the interaction of $D N$ and $D^* N$ states, together with their coupled channels, by using an extension of the local hidden gauge formalism from the light meson sector, which is based on heavy quark spin symmetry. The scheme is based on the use of the impulse approximation at the quark level, with the heavy quarks acting as spectators, which occurs for the dominant terms where there is the exchange of a light meson. The pion exchange and the Weinberg-Tomozawa interactions are generalized and with this dynamics we look for states generated from the interaction, with a unitary coupled channels approach that mixes the pseudoscalar-baryon and vector-baryon states. We find two states with nearly zero width which are associated to the $\Lambda_c(2595)$ and $\Lambda_c(2625)$. The lower state, with $J^P = 1/2^-$, couples to $D N$ and $D^* N$, and the second one, with $J^P = 3/2^-$, to $D^* N$. In addition to these two $\Lambda_c$ states, we find four more states with $I=0$, one of them nearly degenerate in two states of $J=1/2,\ 3/2$. Furthermore we find three states in $I=1$, two of them degenerate in $J=1/2, 3/2$.Comment: v3: version to appear in Eur.Phys.J.

Description of ρ(1700)\rho (1700) as a ρKKˉ\rho K \bar{K} system with the fixed center approximation

We study the $\rho K\bar{K}$ system with an aim to describe the $\rho (1700)$ resonance. The chiral unitary approach has achieved success in a description of systems of the light hadron sector. With this method, the $K \bar{K}$ system in the isospin sector $I=0$, is found to be a dominant component of the $f_0 (980)$ resonance. Therefore, by regarding the $K\bar{K}$ system as a cluster, the $f_0 (980)$ resonance, we evaluate the $\rho K\bar{K}$ system applying the fixed center approximation to the Faddeev equations. We construct the $\rho K$ unitarized amplitude using the chiral unitary approach. As a result, we find a peak in the three-body amplitude around 1739 MeV and a width of about 227 MeV. The effect of the width of $\rho$ and $f_0 (980)$ is also discussed. We associate this peak to the $\rho (1700)$ which has a mass of $1720 \pm 20$ MeV and a width of $250 \pm 100$ MeV

General Relationship Between the Entanglement Spectrum and the Edge State Spectrum of Topological Quantum States

We consider (2+1)-dimensional topological quantum states which possess edge states described by a chiral (1+1)-dimensional Conformal Field Theory (CFT), such as e.g. a general quantum Hall state. We demonstrate that for such states the reduced density matrix of a finite spatial region of the gapped topological state is a thermal density matrix of the chiral edge state CFT which would appear at the spatial boundary of that region. We obtain this result by applying a physical instantaneous cut to the gapped system, and by viewing the cutting process as a sudden "quantum quench" into a CFT, using the tools of boundary conformal field theory. We thus provide a demonstration of the observation made by Li and Haldane about the relationship between the entanglement spectrum and the spectrum of a physical edge state.Comment: 7 pages, 2 figures. A presentation of this work can be found in the following talk at KITP: http://online.itp.ucsb.edu/online/compqcm10/qi

Resolution of Occlusive Carotid Artery Thrombus Treated with Anticoagulation as Demonstrated on Duplex Ultrasonography.

BACKGROUND AND PURPOSE: While the majority of cerebral ischemic events due to carotid occlusive disease result from atherosclerotic plaque rupture, intraluminal carotid artery thrombus occasionally occurs in patients without preexisting carotid atherosclerosis. Identification of nonatherosclerotic thrombus as the cause of the carotid occlusive disease can obviate the need for an interventional procedure, and resolution of thrombus can be monitored with B-mode duplex ultrasonography. METHODS: We reviewed 3 patients treated on The Mount Sinai Hospital Stroke Unit with anticoagulation for nonatherosclerotic carotid thrombi and followed with serial Doppler ultrasonogrpahy for resolution of thrombus. RESULTS: Occlusive carotid thrombus was successfully treated in all 3 patients with systemic anticoagulation. B-mode duplex ultrasonography allowed for demonstration of resolving thrombus. CONCLUSION: Differentiation between a stenotic plaque and occlusive thrombus can be achieved by ultrasonographic analysis of thrombus morphology, attachment site potential, and characteristics of a resolving thrombus. Systemic anticoagulation can safely and effectively eliminate the risk for future embolization and complete occlusion of the carotid artery in patients who present with transient ischemic events or completed infarcts of small size