10,753 research outputs found
B Decays in an Asymmetric Left-Right Model
Motivated by recently observed disagreements with the SM predictions in
decays, we study transitions in an asymmetric class of 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
, , and
mixing to restrict the parameters of the model: as well as the elements of the right-handed
quark mixing matrix . We present a comparison with the more commonly
used (manifest) left-right symmetric model. Our analysis exposes the parameters
most sensitive to 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
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
We construct the Liouville operator for the SU(2) classical colored Coulomb
plasma (cQGP) for arbitrary values of the Coulomb coupling , 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 near the liquid point. This minimum
follows from the cross-over between the single particle collisional regime
which drops as and the hydrodynamical collisional regime which
rises as . The self-diffusion constant drops as
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
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
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 is GeV and mostly Standard Model-like while
are all relatively heavy. Furthermore, the ratio of Higgs vevs,
, is relatively unconstrained. In contrast to this, in the 4GMSSM,
heavy fourth generation fermion loops drive the masses of to large
values while the CP-odd boson, , can remain relatively light and 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 may lead to a
potential signal in the channel at the LHC, may first be
observed in the 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 masses of and . We find that the
CP-even states are highly mixed and can have atypical branching
fractions. Precision electroweak constraints, particularly for the light
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
We study, in this paper, curvature inheritance symmetry (CI),
, where 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., ) 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
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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