Search results for "Maxima"
showing 10 items of 371 documents
New Results on Multiphoton Free-Free Transitions
1988
Recently some of the present authors have reported on calculations concerning free-free transitions in the presence of very strong laser fields,1 in which a number of peculiar features were clearly displayed (among others, well pronounced maxima in the total cross sections and an oscillatory structure). In particular, those calculations concerned total cross sections of direct and inverse multiphoton bremsstrahlung, for several numbers of exchanged photons as functions of the field intensity. Figs. 1 and 2 show a sample of the typical results reported in Ref. 1.
Study of the structure of the Hoyle state by refractive α-scattering
2014
α + 12C elastic and inelastic to the Hoyle state (0+ 2, 7.65 MeV) differential cross-sections were measured at the energies 60 and 65 MeV with the aim of testing the microscopic wave function [1] widely used in modern structure calculations of 12C. Deep rainbow (Airy) minima were observed in all four curves. The minima in the inelastic angular distributions are shifted to the larger angles relatively those in the elastic ones, which testify the radius enhancement of the Hoyle state. In general, the DWBA calculations failed to reproduce the details of the cross sections in the region of the rainbow minima in the inelastic scattering data. However, by using the phenomenological density with r…
Simulation of propagation characteristics of ultrasonic guided waves in fractured long bone
2008
Using ultrasonic guided waves (GW) to assess fractures in long bones has gained considerable attention. This paper focuses on using an improved hybrid boundary element method (HBEM) to analyze and calculate reflection coefficients (RC) and transmission coefficients (TC) of low-order GWs for cracks with different depth-to-width ratios (d/w) in fractured long bones. The results showed that the primary received modes, which include the transmitted and reflected modes, are the same as the incident modes. For some values of d/w, the TC of different GW always had local maxima at adjacent frequencies. For some other cracks with different d/w, most of the TC curves had local maxima of which frequen…
Location of transition states and stable intermediates by MINIMAX/MINIMI optimization of synchronous transit pathways
1983
The MINIMAX/MINIMI concept for the location of transition states and/or stable intermediates of chemical reactions is introduced, based on the synchronous transit method. According to this strategy, minimization of quadratic synchronous transit path maxima or minima is achieved by constrained exhaustive optimization of internal coordinates. The method and its efficiency are demonstrated for two-dimensional model surfaces as well as for thermally allowed electrocyclic interconversions of cyclopropyl-/allyl-cation and cyclobutene-/butadiene (gauche) within the framework of MNDO-SCF calculations. Thus, in both cases a direct comparison with the exact solution determined by minimization of the …
Corrigendum to “On magnetic guidance of charged particles” [Phys. Lett. B 755 (2016) 409–413]
2016
The quantities α′ n and α′ n f are the positions where R(α) in Eqs. (7) and (9) have their maxima, respectively. In Fig. 1(a) the approximation based on these equations is compared with exact results obtained on the basis of Ref. [3]. The position of the spikes are now exactly reproduced. However, for small R ’s there remain some deviations. In particular, for the lowest orbit the expression (α2 + − α2 0) of [2, Eq. (13)] gets imaginary for R/r0 < 0.246 and causes a little kink, see Fig. 1(a). This fact prompted Dubbers [2] replacing for R ≤ 0.34 the quantity α+(R) by the approximation which reads corrected [4] α0[1 + (R/r0)/(8 sin2 α0/2)]. In addition, the statement in Ref. [2] that normal…
Restricted flavor structure of soft SUSY breaking trilinear couplings
2000
We analyze the flavor structure of the trilinear couplings in the different theoretical models of SUSY breaking. We generically obtain A_{ij}= A^L_i + A^R_j in all the models examined. In fact, this is the rigorous form when SUSY breaking effects appear through the Kahler metric of chiral fields or through wave-function renormalization. Indeed, the low-energy phenomenological requirements from the absence of charge and color breaking minima and the measurements in flavor changing neutral current (FCNC) observables strongly favor this restricted form of the trilinear matrices. As a straightforward consequence, the number of unknown parameters associated with the trilinear couplings is decrea…
Charge Breaking Minima in the Broken R-parity Minimal Supersymmetric Standard Model
2005
We reconsider the possible presence of charge and colour breaking minima in the scalar potential of the minimal supersymmetric standard model (MSSM) and its minimal generalization with R-parity explicitly broken by bilinear terms (RMSSM). First we generalize some results previously derived for the MSSM case. Next we investigate how robust is the MSSM against its RMSSM extension. We examine the constraints on the RMSSM parameter space that follow from the required absence of charge breaking minima in the scalar potential. We point out the possibility of generating non--zero vacuum expectation values for the charged Higgs field which is not present in the MSSM. However, given the smallness of…
Three-Dimensional 3-State Potts Model Revisited With New Techniques
1997
We report a fairly detailed finite-size scaling analysis of the first-order phase transition in the three-dimensional 3-state Potts model on cubic lattices with emphasis on recently introduced quantities whose infinite-volume extrapolations are governed `only' by exponentially small terms. In these quantities no asymptotic power series in the inverse volume are involved which complicate the finite-size scaling behaviour of standard observables related to the specific-heat maxima or Binder-parameter minima. Introduced initially for strong first-order phase transitions in q-state Potts models with ``large enough'' q, the new techniques prove to be surprisingly accurate for a q value as small …
ELECTROWEAK THEORY AND THE NEUTRINO-MASS AND NEUTRINO-OSCILLATION QUESTIONS
2007
It is shown that both conjectures of neutrino mass and neutrino oscillation can be made really well-grounded within the Standard Model provided that one adopts a recent new version of the electroweak scheme spontaneously giving also a fundamental explanation for the so-called "maximal parity-violation" effect. A crucial role is played by the prediction of two distinct, scalar and pseudoscalar, replicas of (electron, muon, and tau) lepton numbers that could fully account for an actual non-coincidence between neutrino mass-eigenstates and gauge-eigenstates.
Production of charged pions, kaons, and (anti-)protons in Pb-Pb and inelastic pp collisions at sNN=5.02 TeV
2020
Mid-rapidity production of $\pi^{\pm}$, $\rm{K}^{\pm}$ and ($\bar{\rm{p}}$)p measured by the ALICE experiment at the LHC, in Pb-Pb and inelastic pp collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV, is presented. The invariant yields are measured over a wide transverse momentum ($p_{\rm{T}}$) range from hundreds of MeV/$c$ up to 20 GeV/$c$. The results in Pb-Pb collisions are presented as a function of the collision centrality, in the range 0$-$90%. The comparison of the $p_{\rm{T}}$-integrated particle ratios, i.e. proton-to-pion (p/$\pi$) and kaon-to-pion (K/$\pi$) ratios, with similar measurements in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV show no significant energy dependence. B…