10,574 research outputs found

    B Decays in an Asymmetric Left-Right Model

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    Motivated by recently observed disagreements with the SM predictions in BB decays, we study bd,sb \to d, s transitions in an asymmetric class of SU(2)L×SU(2)R×U(1)BLSU(2)_L \times SU(2)_R \times U(1)_{B-L} models, with a simple one-parameter structure of the right handed mixing matrix for the quarks, which obeys the constraints from kaon physics. We use experimental constraints on the branching ratios of bsγb \to s \gamma, bceνˉeb \to c e {\bar \nu}_e, and Bd,s0Bˉd,s0B_{d,s}^0 -\bar{B}^0_{d,s} mixing to restrict the parameters of the model: gR/gL,MW2,MH±,tanβ\displaystyle {g_R}/{g_L}, M_{W_2}, M_{H^\pm}, \tan \beta as well as the elements of the right-handed quark mixing matrix VCKMRV^R_{CKM}. We present a comparison with the more commonly used (manifest) left-right symmetric model. Our analysis exposes the parameters most sensitive to bb transitions and reveals a large parameter space where left- and right-handed quarks mix differently, opening the possibility of observing marked differences in behaviour between the standard model and the left-right model.Comment: 32 pages and 8 figure

    Improved AdS/QCD Model with Matter

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    We study an improved AdS/QCD model at finite temperature and chemical potential. An Ansatz for the beta-function for the boundary theory allows for the derivation of a charged dilatonic black hole in bulk. The solution is asymptotically RN-AdS in the UV and AdS2 * R3 in the IR. We discuss the thermodynamical aspects of the solution. The fermionic susceptibilities are shown to deviate from the free fermionic limits at asymptotic temperatures despite the asymptotically free nature of the gauge coupling at the boundary. The Polyakov line, the temporal and spatial string tensions dependence on both temperature and chemical potential are also discussed

    Classical Strongly Coupled QGP: VII. Shear Viscosity and Self Diffusion

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    We construct the Liouville operator for the SU(2) classical colored Coulomb plasma (cQGP) for arbitrary values of the Coulomb coupling Γ=V/K\Gamma=V/K, the ratio of the mean Coulomb to kinetic energy. We show that its resolvent in the classical colored phase space obeys a hierarchy of equations. We use a free streaming approximation to close the hierarchy and derive an integral equation for the time-dependent structure factor. Its reduction by projection yields hydrodynamical equations in the long-wavelength limit. We discuss the character of the hydrodynamical modes at strong coupling. The shear viscosity is shown to exhibit a minimum at Γ8\Gamma\approx 8 near the liquid point. This minimum follows from the cross-over between the single particle collisional regime which drops as 1/Γ5/21/\Gamma^{5/2} and the hydrodynamical collisional regime which rises as Γ1/2\Gamma^{1/2}. The self-diffusion constant drops as 1/Γ3/21/\Gamma^{3/2} irrespective of the regime. We compare our results to molecular dynamics simulations of the SU(2) colored Coulomb plasma. We also discuss the relevance of our results for the quantum and strongly coupled quark gluon plasma (sQGP)Comment: 36 pages, 14 figure

    Perbandingan Analisis Finansial USAha Penangkapan Payang Rumpon Dan Payang Lampu Di Pelabuhan Perikanan Pantai (Ppp) Tawang Kabupaten Kendal

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    Kabupaten Kendal memiliki Pelabuhan Perikanan Pantai (PPP) Tawang yang terletak di Desa Gempolsari kecamatan Rowosari. PPP Tawang tersebut membawahi 4 TPI. TPI Tawang merupakan TPI terbesar yang ada di kabupaten Kendal dengan jumlah produksi pada tahun 2011 sebesar 1.530,8 ton. Alat tangkap yang digunakan sebagai objek penelitian adalah alat tangkap payang di Pelabuhan Perikanan Pantai Tawang, Kendal. Tujuan dari penelitian ini adalah untuk menganalisis teknis penangkapan payang rumpon dan payang lampu serta membandingkan kelayakan USAha penangkapan dengan menganalisis aspek finansial USAha penangkapan payang lampu dan payang rumpon dengan menghitung kriteria NPV (Net Present Value), IRR (Internal Rate of Return), PP (Payback Period), dan B/C Ratio. Penelitian ini dilaksanakan pada bulan September-Oktober 2012. Metode penelitian yang digunakan adalah metode deskriptif bersifat studi kasus dengan jumlah sampel 23 nelayan. Metode pengambilan sampel yang digunakan adalah purposive sampling. Hasil penelitian menunjukkan bahwa USAha alat tangkap payang lampu dan payang rumpon layak untuk dijalankan, karena mempunyai nilai NPV payang rumpon sebesar Rp. 331.543.445,- (NPV = positif); IRR sebesar 76 % (IRR> i); PP selama 2 tahun 2 bulan dan B/C Ratio sebesar 1,36 (> 1). Sedangkan untuk nilai NPV payang lampu Rp. 357.775.712,- (NPV = positif); IRR sebesar 61 % (IRR> i); PP selama 2 tahun 4 bulan dan B/C Ratio sebesar 1,30 (> 1). Payang rumpon lebih layak dijalankan dibandingkan dengan payang lampu karena mempunyai nilai IRR dan B/C yang lebih tinggi dari payang rumpon selain itu tingkat pengembalian modal payang rumpon juga lebih cepat dari payang lampu

    Higgs Properties in the Fourth Generation MSSM: Boosted Signals Over the 3G Plan

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    The generalization of the MSSM to the case of four chiral fermion generations (4GMSSM) can lead to significant changes in the phenomenology of the otherwise familiar Higgs sector. In most of the 3GMSSM parameter space, the lighter CP-even hh is 115125\sim 115-125 GeV and mostly Standard Model-like while H,A,H±H,A,H^\pm are all relatively heavy. Furthermore, the ratio of Higgs vevs, tanβ\tan \beta, is relatively unconstrained. In contrast to this, in the 4GMSSM, heavy fourth generation fermion loops drive the masses of h,H,H±h,H,H^\pm to large values while the CP-odd boson, AA, can remain relatively light and tanβ\tan \beta is restricted to the range 1/2 \lsim \tan \beta \lsim 2 due to perturbativity requirements on Yukawa couplings. We explore this scenario in some detail, concentrating on the collider signatures of the light CP-odd Higgs at both the Tevatron and LHC. We find that while ggAgg \to A may lead to a potential signal in the τ+τ\tau^+\tau^- channel at the LHC, AA may first be observed in the γγ\gamma \gamma channel due to a highly loop-enhanced cross section that can be more than an order of magnitude greater than that of a SM Higgs for AA masses of 115120\sim 115-120 and tanβ<1\tan\beta<1. We find that the CP-even states h,Hh,H are highly mixed and can have atypical branching fractions. Precision electroweak constraints, particularly for the light AA parameter space region, are examined in detail.Comment: 20 pages, 7 figures; typos fixed, refs adde

    Curvature Inheritance Symmetry In Riemannian Spaces with Applications to String Cloud and String Fluids

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    We study, in this paper, curvature inheritance symmetry (CI), £ξRbcda=2αRbcda\pounds_{\xi}R_{bcd}^{a}=2\alpha R_{bcd}^{a}, where α\alpha is a scalar function, for string cloud and string fluid in the context of general relativity. Also, we have obtained some result when a proper CI (i.e., α0\alpha \neq 0) is also a conformal Killing vector.Comment: 14 pages, Latex, no figures, to appear in the International Journal of Modern Physics D (IJMPD), Vol.8, No.5(Oct.,1999

    Study and modification of the reactivity of carbon fibers

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    The reactivity to air of polyactylonitrile-based carbon fiber cloth was enhanced by the addition of metals to the cloth. The cloth was oxidized in 54 wt% nitric acid in order to increase the surface area of the cloth and to add carbonyl groups to the surface. Metal addition was then achieved by soaking the cloth in metal acetate solution to effect exchange between the metal carbon and hydrogen on the carbonyl groups. The addition of potassium, sodium, calcium and barium enhanced fiber cloth reactivity to air at 573 K. Extended studies using potassium addition showed that success in enhancing fiber cloth reactivity to air depends on: extent of cloth oxidation in nitric acid, time of exchange in potassium acetate solution and the thoroughness of removing metal acetate from the fiber pore structure following exchange. Cloth reactivity increases essentially linearly with increase in potassium addition via exchange
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