Determinations of |V_ub| and |V_cb| from measurements of B -> X_u,c\ell\nu differential decay rates

Methods are described in the framework of light-cone expansion which allow one to determine the Cabibbo-Kobayashi-Maskawa matrix elements |V_ub| and |V_cb| from measurements of the differential decay rates as a function of the scaling variables in the inclusive semileptonic decays of B mesons. By these model-independent methods the dominant hadronic uncertainties can be avoided and the B -> X_u\ell\nu decay can be very efficiently differentiated from the B -> X_c\ell\nu decay, which may lead to precise determinations of |V_ub| and |V_cb|.Comment: 11 pages, 2 figures, version as published in Mod. Phys. Lett. A, more discussion, references added, title chang

Variation of the solar magnetic flux spectrum during solar cycle 23

By using the unique database of SOHO/MDI full disk magnetograms from 1996 September to 2011 January, covering the entire solar cycle 23, we analyze the time-variability of the solar magnetic flux spectrum and study the properties of extended minimum of cycle 23. We totally identify 11.5 million magnetic structures. It has been revealed that magnetic features with different magnetic fluxes exhibit different cycle behaviors. The magnetic features with flux larger than $4.0 \times 10^{19}$ Mx, which cover solar active regions and strong network features, show exactly the same variation as sunspots; However, the remaining $82\%$ magnetic features which cover the majority of network elements show anti-phase variation with sunspots. We select a riterion that the monthly sunspot number is less than 20 to represent the Sun's low activity status. Then we find the extended minimum of cycle 23 is characterized by the long duration of low activity status, but the magnitude of magnetic flux in this period is not lower than previous cycle. Both the duration of low activity status and the minimum activity level defined by minimum sunspot number show a century period approximately. The extended minimum of cycle 23 shows similarities with solar cycle 11, which preceded the mini-maxima in later solar cycles. This similarity is suggestive that the solar cycles following cycle 23 are likely to have low activity.Comment: 24 pages, 7 figures, accepted by JGR in 201

Phase-kicked control of counter-rotating interactions in the quantum Rabi model

We present an interaction scheme to control counter-rotating terms in the quantum Rabi model. We show that by applying a sequence of $\pi/2$ phase kicks to a two-level atom and a single mode quantized field, the natural dynamics of the Rabi model can be interrupted in a way that counter-rotating transitions can be significantly enhanced. This is achieved by a suitable timing of the phase kicks determined by a phase matching condition. If the time between successive kicks is sufficiently short, our scheme is turned into a dynamical decoupling problem in which the effects of counter-rotating terms can be strongly suppressed under ultrastrong coupling.Comment: 6 pages, 6 figure

Low ionization state plasma in CMEs

The Ultraviolet Coronagraph Spectrometer on board the Solar and Heliospheric Observatory (SOHO) often observes low ionization state coronal mass ejection (CME) plasma at ultraviolet wavelengths. The CME plasmas are often detected in O VI (3x10^5K), C III (8x10^4K), LyA, and LyB, with the low ionization plasma confined to bright filaments or blobs that appear in small segments of the UVCS slit. On the other hand, in situ observations by the Solar Wind Ion Composition Spectrometer (SWICS) on board Advanced Composition Explorer (ACE) have shown mostly high ionization state plasmas in the magnetic clouds in interplanetary coronal mass ejections (ICME) events, while low ionization states are rarely seen. In this analysis, we investigate whether the low ionization state CME plasmas observed by UVCS occupy small enough fractions of the CME to be consistent with the small fraction of ACE ICMEs that show low ionization plasma, or whether the CME plasma must be further ionized after passing the UVCS slit. To do this, we determine the covering factors of low ionization state plasma for 10 CME events. We find that the low ionization state plasmas in CMEs observed by UVCS show average covering factors below 10%. This indicates that the lack of low ionization state ICME plasmas observed by the ACE results from a small probability that the spacecraft passes through a region of low ionization plasma. We also find that the low ionization state plasma covering factors in faster CMEs are smaller than in slower CMEs.Comment: 18 pages, 4 figures, To appear in Astrophysical Journa

Valuation of human deaths and illnesses resulting from pesticide uses in the United States

The objective of this study is to measure the costs associated with the unintentional human deaths and acute illnesses resulting from pesticide uses. This study also estimated comparative health costs among alternative pesticides that can be used for a certain crop. The annual total cost of human deaths and illnesses resulting from pesticide uses in the United States is estimated at $38.83 million. The average health cost per 1,000 pounds use ranges from$.40 for 2,4,D to $23,128 for diquat.Health Economics and Policy,

Relationship between spin squeezing and single-particle coherence in two-component Bose-Einstein condensates with Josephson coupling

We investigate spin squeezing of a two-mode boson system with a Josephson coupling. An exact relation between the squeezing and the single-particle coherence at the maximal-squeezing time is discovered, which provides a more direct way to measure the squeezing by readout the coherence in atomic interference experiments. We prove explicitly that the strongest squeezing is along the $J_z$ axis, indicating the appearance of atom number-squeezed state. Power laws of the strongest squeezing and the optimal coupling with particle number $N$ are obtained based upon a wide range of numerical simulations.Comment: 4 figures, revtex4, new refs. are adde

Strongly Nonlinear Waves in 3D Phononic Crystals

Three dimensional phononic crystal ("sonic vacuum" without prestress) was assembled from 137 vertical cavities arranged in hexagonal pattern in Silicone matrix filled with stainless steel spheres. This system has unique strongly nonlinear properties with respect to wave propagation inherited from nonlinear Hertz type elastic contact interaction. Trains of strongly nonlinear solitary waves excited by short duration impact were investigated. Solitary wave with speed below sound speed in the air and reflection from the boundary of two "sonic vacuums" were detected