B → X_sγ in BLMSSM

Applying the effective Lagrangian method,we study the flavor changing neutral current process b→ sγwithin the minimal supersymmetric extension of the Standard Model,where baryon and lepton numbers are local gauge symmetries.Constraints on the parameters are investigated numerically with the experimental data for the branching ratio of B→ X_sγ.Additionally,we present the corrections to direct CP-violation in B→ X_sγ and time-dependent CP-asymmetry in B→K~*γ.With appropriate assumptions on the parameters,we find the direct CP-violation Acp is very small,while one-loop contributions to S_(K~*_γ) can be significant.     

χcJ Decays into B\bar B in Quark-Pair Creation Model

A quark pair creation model is introduced to study the χ_cJ exclusive decays into baryon-antibaryon pairs. The decay widths for processes χ_cJ→B\bar B (J=0,2;B=Λ,Σ⁰, Ξ^-) are evaluated phenomenologically with an explicit inclusion of the properties for outgoing baryons described by wave functions in the naive quark model. The results show that states χ_cJ (J=0,2) decay into Λ\bar Λ pair with a larger branching ratio than into p\bar p pair.     

CP violation in B→φKs decay in R-parity violating supersymmetry

In the framework of R-parity violating supersymmetry, we investigate the time dependent CP asymmetry SφKs anomaly of B→φKs decay. When the values of the weak phase φ in the R-parity violating coupling fall into certain parameter spaces (246°<φ<263°) we find that this anomaly can be easily ex-plained; at the same time, the branching ratio of B →φKs decay can also be in agreement with experimental measurements.     

CP violation in B→φKs decay in R-parity violating supersymmetry

In the framework of R-parity violating supersymmetry, we investigate the time dependent CP asymmetry SφKs anomaly of B→φKs decay. When the values of the weak phase φ in the R-parity violating coupling fall into certain parameter spaces （246°〈 φ 〈 263°） we find that this anomaly can be easily explained; at the same time, the branching ratio of B→φKs decay can also be in agreement with experimental measurements.     

Bénard-Marangoni instability in a viscoelastic ferrofluid

In this paper we report theoretical and numerical results on convection of a magnetic fluid in a viscoelastic carrier liquid. The viscoelastic properties are given by the Oldroyd model. We impose the lower interface to be rigid, whereas the upper one is free and is assumed to be non-deformable and flat. Also, at the upper interface the surface tension is taken to vary linearly with the temperature. Using a spectral method we calculate numerically the convective thresholds for both stationary and oscillatory bifurcations. The effect of the viscoelasticity and the Kelvin force on the instability thresholds are emphasized.     

Self-pulsing Instability in Two-PhotonLasers of the Class B

1.IntroductionLasersystemshavebccnkno`"ntounderg0stabiIitychangesunderccrtainconditi0ns.Inthesingle-m0de1asers,forexampIc,thereisasecondthresh0Idvalueabovewhichafurtherinstability,namely,sclf-pulsing,sctsin[1'2J.H0\\'cver,inthccaseof0nc-ph0tonlasersoftheclassB,n0self-pulsinginstabilityoccursf0rthefrcc-runningandatresonance.Instabili-tiesin'tx"o-ph0t0nlasersystc112shavcals0bceninvcstigatcdthe0rctically.Inrecentyears,two-phQtonlaser0scillationhasbccnobscrvedinaFabry-Per0tcavityfil1edx"ithrub…     

Role of poloidal E × B drift in divertor heat transport in DIII-D

Simulations for DIII-D high confinement mode plasmas with the multifluid code UEDGE show a strong role of poloidal E × B drifts on divertor heat transport, challenging the paradigm of conduction-limited scrape-off layer (SOL) transport. While simulations with reduced drift magnitude are well aligned with the assumption that electron heat conduction dominates the SOL heat transport, simulations with drifts predict that the poloidal convective E × B heat transport dominates over electron heat conduction in both attached and detached conditions. As poloidal E × B flow propagates across magnetic field lines, poloidal transport with shallow magnetic pitch angles can reach values that are of the same order as would be provided by sonic flows parallel to the field lines. These flows can lead to strong convection-dominated divertor heat transport, increasing the poloidal volume of radiative power front, consistent with previous measurements at DIII-D. Due to these convective flows, the Lengyel integral approach, assuming zero convective fraction, is expected to provide a pessimistic estimate for the radiative capability of impurities in the divertor. For the DIII-D simulations shown here, the Lengyel integral approach underestimates the radiated power by a factor of 6, indicating that, for reliable DIII-D divertor power exhaust predictions, full two-dimensional (2D) calculations, including drifts, would be necessary.     

Interface mixing in Fe–B–Ag multilayers

Multilayers with Ag/Fe/B and Ag/B/Fe layer sequence were studied in order to reveal differences of top and bottom interfaces of Fe. The hyperfine field distribution depends on the layer sequence and the differences could be attributed to a different B concentration distribution at the top and bottom Fe–B interface.     

Side wall effects in Rayleigh Bénard experiments

In Rayleigh Bénard experiments, the side wall conductivity is traditionally taken into account by subtracting the empty cell heat conductivity from the measured one. We present a model showing that the correction to apply could be considerably larger. We compare to experiments and find good agreement. One of the consequences is that the Nusselt behavior for Ra < 10¹⁰ could be closer to Nu∝Ra ^1/3 than currently assumed. Also, the wall effect can appear as a continuous change in the γ exponent Nu∝Ra ^γ. Received 26 April and Received in final form 1st October 2001     

Nonlinearity acoustic parameter B/A in organic liquids

1IntroductionWiththeapplicationofultrasoundinmedicaldiagnosisandtherapy,somenonlinearacousticphenomenawereobserved,andmanyinvestigatorsdidsomeresearchworksinthisfield.Theyfoundthat,thenonlinearityacousticparameterB/Awasnotonlytheparameterdescribingthedegreeofnonlinearitybutalsotheparameterwhichmightprovidesomestructuralandstateinformationofmedia,andnonlinearityacousticparameterB/AwasofpotentialpossibilitytobetreatedasanewparameterintissueCharacterizinganddiagnosisimaging.Thestudyofrelationbe…     

2α + t Cluster Structure in 11B

Structures of excited states in ¹¹B are investigated with a method of β – γ constraint antisymmetrized molecular dynamics in combination with the generator coordinate method. Various cluster structures are suggested in excited states. For negative-parity states, we suggest a band with a 2α + t cluster structure. This band starts from the ${3/2^{-}_{3}}$ state and can correspond to the experimental band observed recently. We find that the feature of the ${3/2^{-}_{3}}$ is quite similar to the ${0^{+}_{2}}$ state in ¹²C.     

Survival probability in one dimension for theA+B→B reaction with hard-core repulsion

We study the effect of hard-core repulsion (known as the bus effect) betweenB particles on the reaction-diffusion systemA+BB in the continuous-time random walk model in one dimension with theA particles stationary. We show rigorously that the survival probability of theA particles is asymptotically bounded asC ₁lim _t{[–logS(t)]/t ^0.5}C ₂, whereC ₁ andC ₂ are constants. We also do simulations to confirm our results.     

Probe the R-Parity Violating Supersymmetry Effects in the B0s—B0s Mixing

The recent measurements of the B_s mass difference Δ M_s by the CDF and DO collaborations are roughly consistent with the Standard Model predictions, therefore, these measurements will afford an opportunity to constrain new physics scenarios beyond the Standard Model. We consider the impact of the R-parity violating supersymmetry in the B0s—B0s mixing, and use the latest experimental results of ΔM_s to constrain the size of the R-parity violating tree level couplings in the B0s—B0s mixing. Then, using the constrained RPV parameter space from ΔM_s, we show the R-parity violating effects on the B_s width difference ΔΓ_s.     

Evidence for slow velocity relaxation in front propagation in Rayleigh–Bénard convection

Recent theoretical work has shown that so-called pulled fronts propagating into an unstable state always converge very slowly to their asymptotic speed and shape. In the light of these predictions, we reanalyze earlier experiments by Fineberg and Steinberg on front propagation in a Rayleigh–Bénard cell. In contrast to the original interpretation, we argue that in the experiments the observed front velocities were some 15% below the asymptotic front speed and that this is in rough agreement with the predicted slow relaxation of the front speed for the time scales probed in the experiments. We also discuss the possible origin of the unusually large variation of the wavelength of the pattern generated by the front as a function of the dimensionless control parameter.