Lambda-parameter of lattice QCD with Symanzik improved gluon actions

We compute the ratio Lambda_L/Lambda_MS, where the scale parameter Lambda_L is associated with a lattice formulation of QCD. We consider a 3-parameter family of gluon actions, which are most frequently used for O(a) improvement a` la Symanzik. The gluon action is put togeter with standard discretizations for fermions (Wilson/clover, overlap), to provide Lambda_L for several possible combinations of fermion and gluon actions. We employ the background field technique in order to calculate the 1PI 2-point function of the background field; this leads to the coupling constant renormalization function, Z_g, at 1-loop level. Our results are obtained for an extensive range of values for the Symanzik coefficients.Comment: 11 pages, 3 figures, 3 table

The Critical Hopping Parameter in O(a) improved Lattice QCD

We calculate the critical value of the hopping parameter, $\kappa_c$, in O(a) improved Lattice QCD, to two loops in perturbation theory. We employ the Sheikholeslami-Wohlert (clover) improved action for Wilson fermions. The quantity which we study is a typical case of a vacuum expectation value resulting in an additive renormalization; as such, it is characterized by a power (linear) divergence in the lattice spacing, and its calculation lies at the limits of applicability of perturbation theory. The dependence of our results on the number of colors $N$, the number of fermionic flavors $N_f$, and the clover parameter $c_{SW}$, is shown explicitly. We compare our results to non perturbative evaluations of $\kappa_c$ coming from Monte Carlo simulations.Comment: 11 pages, 2 EPS figures. The only change with respect to the original version is inclusion of the standard formulae for the gauge fixing and ghost parts of the action. Accepted for publication in Physical Review

Effects of doping on thermally excited quasiparticles in the high-TcT_c superconducting state

The physical properties of low energy superconducting quasiparticles in high- $T_c$ superconductors are examined using magnetic penetration depth and specific heat experimental data. We find that the low energy density of states of quasiparticles of La$_{2-x}$Sr$_x$CuO$_4$ scales with $(x-x_c)/T_c$ to the leading order approximation, where $x_c$ is the critical doping concentration below which $T_c=0$. The linear temperature term of the superfluid density is renormalized by quasiparticle interactions and the renormalization factor times the Fermi velocity is found to be doping independent.Comment: 3 pages, 3 figures, minor change to the content, fig1 is reploted, to appear in Phys Rev

Universal optimal hole-doping concentration in single-layer high-temperature cuprate superconductors

We argue that in cuprate physics there are two types, hole content per CuO$_2$ plane ($P_{pl}$) and the corresponding hole content per unit volume ($P_{3D}$), of hole-doping concentrations for addressing physical properties that are two-dimensional (2D) and three-dimensional (3D) in nature, respectively. We find that superconducting transition temperature ($T_c$) varies systematically with $P_{3D}$ as a superconducting \textquotedblleft $dome$\textquotedblright with a universal optimal hole-doping concentration $P_{3D}^{opt.}$ = 1.6 $\times$ 10$^{21}$ cm$^{-3}$ for single-layer high temperature superconductors. We suggest that $P_{3D}^{opt.}$ determines the upper bound of the electronic energy of underdoped single-layer high-$T_c$ cuprates.Comment: 8 pages, 4 figures; added references ;accepted for the publication in Supercond. Sci. Technol ; Ref. 13 is revise

Chateaubriand\u27s Florida and His Journey to America

The American writings of Chateaubriand have nearly been forgotten. Despite the beauty of their poetic prose and the power of their descriptions, historians now consider them obsolete. In 1968 the bicentennial year of his birth was celebrated in other parts of the world with special conferences and impressive publications, but in the United States no periodical commemorated the event, and no paper re-evaluating Chateaubriand’s contribution was read in any of the numerous historical meetings. And yet, Chateaubriand was not just another author. During the first half of the nineteenth century his writings played a great part in shaping French, if not European ideas about America. In the Parisian literary salons, eager young intellectuals tried to satisfy their insatiable curiosity about the New World by listening to his exotic tales. Among them was Alexis de Tocqueville, Chateaubriand’s distance cousin. And long after Chateaubriand’s death in 1848, Europeans who visited this country still carried with them preconceptions and cliches derived from his writings

The Background of the Greek Settlers in the New Smyrna Colony

Andrew Turnbull, the principal founder of the New Smyrna Colony, was not the first who thought of bringing Greeks to people Florida. Immediately after the Treaty of Paris in 1763, which transferred Florida into British hands, William Knox, in a memorial to Whitehall, had already made this suggestion in a very convincing way. Knox, who later was Under-Secretary of State for American Affairs from 1770 to 1782, made, in his memorial, a detailed analysis of conditions and possibilities of the newly acquired Province of Florida. Attempting to solve the urgent problem of peopling this area, completely depopulated after the departure of the Spanish, he had formed the opinion that the nature of the soil and climate and the sort of products which were best adapted to both, pointed to a special kind of settlers who ought to be encouraged to establish themselves in Florida

The Hagiographical Relations between Byzantium and the West during the Middle Byzantine Period

In the present study a special reference is made to the hagiographical relations between Byzantium and the West. The first part is dedicated to the "communication" of Byzantium with the West, on the role played by the Lives of Byzantine Saints, the transfer and honor of their relics and pilgrimages. The phenomenon developed after the 4th century, when an attempt was made to create a liturgical and worship communication between the two Churches and the Roman Martyrologium was formed in the West. The second part is dedicated to the "communication" of the West in Byzantium through the honor of the western Saints. In the next paragraph, we talk about "communication" through the holy relics of the Saints, and it is found that the phenomenon mainly concerned Saints of the East. The paper closes with some introductory notes on translators' translation options and techniques.En el presente estudio se hace una referencia especial a las relaciones hagiográficas entre Bizancio y Occidente. La primera parte está dedicada a la "comunicación" de Bizancio con Occidente, sobre el papel desempeñado por las Vidas de los santos bizantinos, la transferencia y el honor de sus reliquias y peregrinaciones. El fenómeno se desarrolló después del siglo IV, cuando se hizo un intento de crear una comunicación litúrgica y de adoración entre las dos Iglesias y el Martirologio Romano en Occidente. La segunda parte está dedicada a la "comunicación" de Occidente en Bizancio a través del honor de los santos occidentales. En el siguiente párrafo, hablamos de la "comunicación" a través de las reliquias santas de los santos, y se descubre que el fenómeno se refería principalmente a los santos de Oriente. El documento se cierra con algunas notas introductorias sobre las opciones y técnicas de traducción de los traductores

Strain-induced interface reconstruction in epitaxial heterostructures

We investigate in the framework of Landau theory the distortion of the strain fields at the interface of two dissimilar ferroelastic oxides that undergo a structural cubic-to-tetragonal phase transition. Simple analytical solutions are derived for the dilatational and the order parameter strains that are globally valid over the whole of the heterostructure. The solutions reveal that the dilatational strain exhibits compression close to the interface which may in turn affect the electronic properties in that region.Comment: 7 pages, 5 figures, to be published in Physical Review