Observation of Top Quark Production in Proton-Nucleus Collisions

Peer reviewe

Study of B Meson Production in p plus Pb Collisions at root s(NN)=5.02 TeV Using Exclusive Hadronic Decays

Peer reviewe

Free flux flow resistivity in strongly overdoped high-T_c cuprate; purely viscous motion of the vortices in semiclassical d-wave superconductor

We report the free flux flow (FFF) resistivity associated with a purely viscous motion of the vortices in moderately clean d-wave superconductor Bi:2201 in the strongly overdoped regime (T_c=16K) for a wide range of the magnetic field in the vortex state. The FFF resistivity is obtained by measuring the microwave surface impedance at different microwave frequencies. It is found that the FFF resistivity is remarkably different from that of conventional s-wave superconductors. At low fields (H<0.2H_c2) the FFF resistivity increases linearly with H with a coefficient which is far larger than that found in conventional s-wave superconductors. At higher fields, the FFF resistivity increases in proportion to \sqrt H up to H_c2. Based on these results, the energy dissipation mechanism associated with the viscous vortex motion in "semiclassical" d-wave superconductors with gap nodes is discussed. Two possible scenarios are put forth for these field dependence; the enhancement of the quasiparticle relaxation rate and the reduction of the number of the quasiparticles participating the energy dissipation in d-wave vortex state.Comment: 9 pages 7 figures, to appear in Phys. Rev.

Ultracold atom-molecule collisions with fermionic atoms

Elastic and inelastic properties of weakly bound s- and p-wave molecules of fermionic atoms that collide with a third atom are investigated. Analysis of calculated collisional properties of s-wave dimers of fermions in different spin states permit us to compare and highlight the physical mechanisms that determine the stability of s-wave and p-wave molecules. In contrast to s-wave molecules, the collisional properties of p-wave molecules are found to be largely insensitive to variations of the p-wave scattering length and that these collisions will usually result in short molecular lifetimes. We also discuss the importance of this result for both theories and experiments involving degenerate Fermi gases.Comment: 6 pages, 2 figure

Measurement of the top quark mass in the dileptonic t(t)over-bar decay channel using the mass observables M-bl, M-T2, and M-blv in pp collisions at root=8 TeV

Peer reviewe

Search for supersymmetry in multijet events with missing transverse momentum in proton-proton collisions at 13 TeV

Peer reviewe

Towards wafer scale inductive determination of magnetostatic and dynamic parameters of magnetic thin films and multilayers

We investigate an inductive probe head suitable for non-invasive characterization of the magnetostatic and dynamic parameters of magnetic thin films and multilayers on the wafer scale. The probe is based on a planar waveguide with rearward high frequency connectors that can be brought in close contact to the wafer surface. Inductive characterization of the magnetic material is carried out by vector network analyzer ferromagnetic resonance. Analysis of the field dispersion of the resonance allows the determination of key material parameters such as the saturation magnetization MS or the effective damping parameter Meff. Three waveguide designs are tested. The broadband frequency response is characterized and the suitability for inductive determination of MS and Meff is compared. Integration of such probes in a wafer prober could in the future allow wafer scale in-line testing of magnetostatic and dynamic key material parameters of magnetic thin films and multilayers

Localization of the number of photons of ground states in nonrelativistic QED

One electron system minimally coupled to a quantized radiation field is considered. It is assumed that the quantized radiation field is {\it massless}, and {\it no} infrared cutoff is imposed. The Hamiltonian, $H$, of this system is defined as a self-adjoint operator acting on \LR\otimes\fff\cong L^2(\BR;\fff), where \fff is the Boson Fock space over L^2(\BR\times\{1,2\}). It is shown that the ground state, \gr, of $H$ belongs to $\cap_{k=1}^\infty D(1\otimes N^k)$, where $N$ denotes the number operator of \fff. Moreover it is shown that, for almost every electron position variable x\in\BR and for arbitrary $k\geq 0$, \|(1\otimes \N)\gr (x) \|_\fff \leq D_ke^{-\delta |x|^{m+1}} with some constants $m\geq 0$, $D_k>0$, and $\delta>0$ independent of $k$. In particular \gr\in \cap_{k=1}^\infty D (e^{\beta |x|^{m+1}}\otimes N^k) for $0<\beta<\delta/2$ is obtained.Comment: 43page

Accurate solutions of Colebrook-White’s friction factor formulae

Estimations of friction factor (Ff) in pipeline systems and fluid transport are essential ingredients in engineering fields and processes. In this paper explicit friction factor formulae (Fff) were proposed and evaluated with an aim of developing error free Fff. General Fff that relate Ff, Reynolds number (Re) and relative roughness (Rr) were proposed. Colebrook – White’s formula was used to compute different Ff for Re between 4 x 103 and 1.704 x 108, and Rr between 1.0 x 10-7 and 0.052 using Microsoft Excel Solver to fix the Fff. The fixed Fff were used to compute Ff for Re between 4 x 103 and 1.704 x 108 and Rr between 1.0 x 10-7 and 0.052. Accuracy of the fixed Fff was evaluated using relative error; model of selection (MSC) and Akaike Information Criterion (AIC) and compared with the previous Fff using Colebrook–White’s Ff as the reference. The study revealed that Ff estimated using the fixed Fff were the same as Ff estimated using Colebrook – White’s Fff. The fixed Fff provided the lowest relative error of (0.02 %; 0.06 % and 0.04 % ), the highest MSC (14.03; 12.42 and 13.07); and the lowest AIC (-73006; -64580 and -67982). The study concluded that modeling of Fff using numerical methods and Microsoft Excel Solver are better tools for estimating Ff in pipeline flow problems.Keywords: Friction factor, MSC; AIC; Reynolds number; Engineering Field; pipe flow, statistical method