# Brazilian Journal of Physics

Brazilian Journal of Physics > 2011 > 41 > 1 > 21-28

Brazilian Journal of Physics > 2011 > 41 > 1 > 50-58

*l*and other regimes. We employ the uniform approximation. The use of our expressions in low-energy scattering of charged particles is discussed and some...

Brazilian Journal of Physics > 2011 > 41 > 1 > 66-70

*SU*(3)

_{ C }⊗

*SU*(3)

_{ L }⊗

*U*(1)

_{ X }(3–3–1) model with right-handed neutrinos, we study the Higgsstrahlung process

*e*

^{ + }

*e*

^{ − }→

*ZH*and calculate the cross section of this process at leading order. Our numerical results showed that the production cross sections for this process can be significantly large as . With reasonable values of the

*Z*′ mass

*M*

_{ Z′},

*Z*′ exchange...

Brazilian Journal of Physics > 2011 > 41 > 1 > 38-43

_{2}at 4.3% enrichment. From its irradiation, the rate of radioactive capture and fission had been measured as a function of the radius of the pellet disk using a Ortec GMX HPGe detector. Lead collimators had been...

Brazilian Journal of Physics > 2011 > 41 > 1 > 71-77

Brazilian Journal of Physics > 2011 > 41 > 1 > 59-65

*q*plays a fundamental role. We derive the deceleration as a function of redshift

*q*(

*z*) in two scenarios:

*Λ*CDM model and modified Chaplygin gas (MCG) model. The function for the MCG model is then fitted to the cosmological data in order to obtain the cosmological parameters that minimize

*χ*

^{2}. We use the Fisher matrix to construct the covariance...

Brazilian Journal of Physics > 2011 > 41 > 1 > 1-6

_{1 − x }Ce

_{ x }Ba

_{2}Cu

_{3}O

_{7 − δ }with

*x*= 0.00, 0.05, and 0.10. The samples were produced by a standard solid-state reaction method, and the microstructure was analyzed by X-ray diffraction. To identify power-law divergences of the conductivity, the results were analyzed in terms of the temperature derivative of the resistivity...

Brazilian Journal of Physics > 2011 > 41 > 1 > 94-101

Brazilian Journal of Physics > 2011 > 41 > 1 > 44-49

*m*1-branes at angle in the presence of the background electric fields, in a partially compact spacetime. The branes have motions along a common direction that is perpendicular to both of them. Using the boundary state formalism, we calculate their interaction amplitude. Some special cases of this interaction will be studied in detail.

Brazilian Journal of Physics > 2011 > 41 > 1 > 29-37

Brazilian Journal of Physics > 2011 > 41 > 1 > 86-93

Brazilian Journal of Physics > 2011 > 41 > 1 > 7-14

Brazilian Journal of Physics > 2011 > 41 > 1 > 78-85

Brazilian Journal of Physics > 2011 > 41 > 1 > 15-20

Brazilian Journal of Physics > 2011 > 41 > 2-3 > 113-117

Brazilian Journal of Physics > 2011 > 41 > 2-3 > 123-128

Brazilian Journal of Physics > 2011 > 41 > 2-3 > 177-183

*p*-brane in the presence of the Kalb–Ramond field

*B*

_{ μν }, an internal

*U*(1) gauge field

*A*

_{ α }and a tachyon field, in the compact spacetime. According to this state, properties of the brane and a closed string, with mixed boundary conditions emitted from it, will be obtained. Using this boundary state, we calculate the interaction...

Brazilian Journal of Physics > 2011 > 41 > 2-3 > 171-176

*ϕ*

^{4}field equation of motion is presented, by constructing a collective coordinate system for the solitary solutions of this model. The interaction of

*ϕ*

^{4}solitons with a delta function potential barrier and also delta function potential well is investigated. Most of the characters of interaction are derived analytically while they...

Brazilian Journal of Physics > 2011 > 41 > 2-3 > 184-194

Brazilian Journal of Physics > 2011 > 41 > 2-3 > 159-166

*c*’ in the linear cum Coulomb potential. While it felicitates the inclusion of standard confinement parameter

*b*= 0.183 GeV

^{2}unlike in previous work, it still falls short of explaining the Isgur-Wise function for the

*B*mesons without ad hoc adjustment of the strong...