816 research outputs found

    Rare BB-Decays and Heavy to Light Semileptonic Transitions in the Isgur and Wise Limit

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    From the experimental branching ratios for B−−−>ρ0l−ΜˉlB^- --> \rho^0 l^-\bar\nu_l and D^+ --> {\overl K}^{*0}({\overl K}^0) e^+ \nu_e one finds, in the Heavy Quark Limit of HQETHQET, ∣Vbu∣=(8.1±1.7)x10−3 |V_{bu}|=(8.1\pm 1.7) x 10^{-3}, larger but consistent with the actual quoted range (2−7)x10−3(2 - 7) x 10^{-3}. In the same framework one predicts for R(B−−>K∗γ)=(2±2)10−2R(B --> K^*\gamma)=( 2 \pm 2 ) 10^{-2}.Comment: 9 pages, 1 Figure avalaible on request from [email protected]

    The enhancement of prostate cancer treatment using gold nanoparticles and high energy photons

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    Gold nanoparticles (AuNPs) are widely used for medical applications, because it ability to convert as colloidal solution, have no interaction with biotic tissue, low toxicity, easy in the detection, and thermally stabile. This study focuses on the treatment of prostate cancer by interaction the gamma ray (6 MeV) with Gold nanoparticles, without the extirpation of prostate. This method occurs in a minimum dose given for the patient for the improvement of radiotherapy that is used in prostate cancer treatment by depended on pair production phenomenon. Keywords: gold nanoparticles(AuNPs), gamma photons, prostate cancer, pair production

    Are Topological Charge Fluctuations in QCD Instanton Dominated?

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    We consider a recent proposal by Horv\'ath {\em et al.} to address the question whether topological charge fluctuations in QCD are instanton dominated via the response of fermions using lattice fermions with exact chiral symmetry, the overlap fermions. Considering several volumes and lattice spacings we find strong evidence for chirality of a finite density of low-lying eigenvectors of the overlap-Dirac operator in the regions where these modes are peaked. This result suggests instanton dominance of topological charge fluctuations in quenched QCD.Comment: LaTeX, 15 pages, 8 postscript figures, minor improvements, version to appear in PR

    The Virtual International Stroke Trials Archive

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    BACKGROUND AND PURPOSE: Stroke has global importance and it causes an increasing amount of human suffering and economic burden, but its management is far from optimal. The unsuccessful outcome of several research programs highlights the need for reliable data on which to plan future clinical trials. The Virtual International Stroke Trials Archive aims to aid the planning of clinical trials by collating and providing access to a rich resource of patient data to perform exploratory analyses. METHODS: Data were contributed by the principal investigators of numerous trials from the past 16 years. These data have been centrally collated and are available for anonymized analysis and hypothesis testing. RESULTS: Currently, the Virtual International Stroke Trials Archive contains 21 trials. There are data on \u3e15,000 patients with both ischemic and hemorrhagic stroke. Ages range between 18 and 103 years, with a mean age of 69+/-12 years. Outcome measures include the Barthel Index, Scandinavian Stroke Scale, National Institutes of Health Stroke Scale, Orgogozo Scale, and modified Rankin Scale. Medical history and onset-to-treatment time are readily available, and computed tomography lesion data are available for selected trials. CONCLUSIONS: This resource has the potential to influence clinical trial design and implementation through data analyses that inform planning

    Measurement of hybrid content of heavy quarkonia using lattice NRQCD

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    Using lowest-order lattice NRQCD to create heavy meson propagators and applying the spin-dependent interaction, cB−g2mqσ⃗⋅B⃗c_B^{} \frac{-g}{2m_q}\vec\sigma\cdot\vec{B}, at varying intermediate time slices, we compute the off-diagonal matrix element of the Hamiltonian for the quarkonium-hybrid two-state system. Thus far, we have results for one set of quenched lattices with an interpolation in quark mass to match the bottomonium spectrum. After diagonalization of the two-state Hamiltonian, we find the ground state of the ΄\Upsilon to show a 0.0035(1)cB20.0035(1)c_B^2 (with cB2∌1.5−3.1c_B^2 \sim 1.5-3.1) probability admixture of hybrid, ∣bbˉg>|b\bar{b}g>.Comment: 11 pages, 4 figures, to appear in Phys Rev

    KEBERLANJUTAN USAHA PENANGKAPAN PURSE SEINE DI PEKALONGAN DITINJAU DARI ASPEK EFISIENSI USAHA

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    Tujuan dari penelitian ini adalah menghitung efiensi teknis usaha penangkapan purse seine di PPN Pekalongan secara stokastik dan deterministik dan menganalisis efisiensi teknis untuk mengetahui prospek keberlanjutan usaha penangkapan purse seine di PPN Pekalongan. Metode analisis menggunakan Stochastic Frontier Analysis (SFA) dan Deterministic Frontier Analysis (DFA). SFA dan DFA merupakan model parametrik yang digunakan untuk mengukur efisiensi teknis. Model 1: DFA dengan data cross-section akan diestimasi dengan COLS. Model 2: SFA dengan data cross-section akan diestimasi dengan ML (Maximum Likelihood). Model 3: SFA dengan data panel diestimasi dengan proses ML. Variabel independent yang digunakan pada penelitian ini adalah lama trip (fishing days atau X1), GRT (Gross Registered Tonnage atau X2) kapal, jumlah ABK (crew members atau X3) sebagai faktor determinan yang digunakan oleh penangkapan purse seine di lokasi penelitian. Dan variabel terikat (Y) adalah output yaitu produksi tangkapan per tahun dari tahun 2015-2017. Fokus penelitian pada kapal purse seine berukuran 60-90 GT. Hasil dari penelitian ini adalah efisiensi teknis dari kedua kelompok kapal menunjukkan nilai inefisiensi dalam penggunaan ketiga variabel input. Hal ini diperkuat dengan hasil nilai korelasi (R) pada metode Deterministik Frontier dan Stokastik Frontier dengan data cross section serta panel data yang rendah (0,39 dan 0,311). Variabel X1 (lama trip) memiliki hubungan negatif dengan variabel Y (produksi) sedangkan X2 dan X3 memiliki hubungan positif terhadap Y. Pada armada penangkapan purse seine ukuran 60-90 GT, ketiga variabel input tidak mempunyai pengaruh yang signifikan terhadap perubahan jumlah produksi penangkapan

    Numerical study of O(a) improved Wilson quark action on anisotropic lattice

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    The O(a)O(a) improved Wilson quark action on the anisotropic lattice is investigated. We carry out numerical simulations in the quenched approximation at three values of lattice spacing (aσ−1=1a_{\sigma}^{-1}=1--2 GeV) with the anisotropy Ο=aσ/aτ=4\xi=a_{\sigma}/a_{\tau}=4, where aσa_{\sigma} and aτa_{\tau} are the spatial and the temporal lattice spacings, respectively. The bare anisotropy ÎłF\gamma_F in the quark field action is numerically tuned by the dispersion relation of mesons so that the renormalized fermionic anisotropy coincides with that of gauge field. This calibration of bare anisotropy is performed to the level of 1 % statistical accuracy in the quark mass region below the charm quark mass. The systematic uncertainty in the calibration is estimated by comparing the results from different types of dispersion relations, which results in 3 % on our coarsest lattice and tends to vanish in the continuum limit. In the chiral limit, there is an additional systematic uncertainty of 1 % from the chiral extrapolation. Taking the central value ÎłF=ÎłF∗\gamma_F=\gamma_F^* from the result of the calibration, we compute the light hadron spectrum. Our hadron spectrum is consistent with the result by UKQCD Collaboration on the isotropic lattice. We also study the response of the hadron spectrum to the change of anisotropic parameter, ÎłF→γF∗+ÎŽÎłF\gamma_F \to \gamma_F^* + \delta\gamma_F. We find that the change of ÎłF\gamma_F by 2 % induces a change of 1 % in the spectrum for physical quark masses. Thus the systematic uncertainty on the anisotropic lattice, as well as the statistical one, is under control.Comment: 27 pages, 25 eps figures, LaTe

    b-physics signals of the lightest CP-odd Higgs in the NMSSM at large tan beta

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    We investigate the low energy phenomenology of the lighter pseudoscalar A10A_1^0 in the NMSSM. The A10A_1^0 mass can naturally be small due to a global U(1)RU(1)_R symmetry of the Higgs potential, which is only broken by trilinear soft terms. The A10A_1^0 mass is further protected from renormalization group effects in the large tan⁥ÎČ\tan \beta limit. We calculate the b→sA10b \to s A_1^0 amplitude at leading order in tan⁥ÎČ\tan \beta and work out the contributions to rare KK, BB and radiative ΄\Upsilon-decays and B−BˉB -\bar B mixing. We obtain constraints on the A10A_1^0 mass and couplings and show that masses down to O(10){\cal{O}}(10) MeV are allowed. The bb-physics phenomenology of the NMSSM differs from the MSSM in the appearance of sizeable renormalization effects from neutral Higgses to the photon and gluon dipole operators and the breakdown of the MSSM correlation between the Bs→Ό+Ό−B_s \to \mu^+ \mu^- branching ratio and Bs−BˉsB_s - \bar B_s mixing. For A10A_1^0 masses above the tau threshold the A10A_1^0 can be searched for in b→sτ+τ−b \to s \tau^+ \tau^- processes with branching ratios \lsim 10^{-3}.Comment: 18 pages, 3 figures; references adde
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