34 research outputs found
Izrada gantograma dokovanja na plutajućem doku
Brodovi i razni drugi pomorski objekti nakon određenog vremena provedenog u ekspoataciji, ili zbog nekih izvanrednih okolnosti kao što su havarije, moraju obaviti remont u nekom od remontnih
brodogradilišta. Objekti se najčešće dokuju zbog izvođenja raličitih radova vezanih uz podvodni dio trupa ili zbog periodičnih pregleda vještaka Registra i sl. Primjeri takvih radova su sanacije oštećenja
trupa, radovi na propeleru, listu kormila, AKZ tretman podvodnog dijela trupa. Remont se najčešće odvija na plutajućim dokovima na kojima se brod ili neki pomorski objekt relativno jednostavno digne
iz vode. Uz pomoć plutajućih dokova remont se može izvršiti jednostavno i brzo. Ovaj rad pokazuje detaljan prikaz procesa te akcije potrebne za izvršavanje nekog od istih te njihova moguća poboljšanja
Remarks on the hadronic matrix elements relevant to the SUSY K-Kbar mixing amplitude
We compute the 1-loop chiral corrections to the bag parameters which are
needed for the discussion of the SUSY K-Kbar mixing problem in both finite and
infinite volume. We then show how the bag parameters can be combined among
themselves and with some auxiliary quantities and thus sensibly reduce the
systematic errors due to chiral extrapolations as well as those due to finite
volume artefacts present in the results obtained from lattice QCD. We also show
that in some cases these advantages remain as such even after including the
2-loop chiral corrections. Similar discussion is also made for the K --> pi
electro-weak penguin operators.Comment: 13 pages, 3 figures [added 1 reference and a discussion about the
impact of the NNLO chiral corrections to the "golden ratios" (c.f. Sec.6)
B-parameters of the complete set of matrix elements of (Delta B = 2) operators from the lattice
We compute on the lattice the ``bag'' parameters of the five (Delta B = 2)
operators of the supersymmetric basis, by combining their values determined in
full QCD and in the static limit of HQET. The extrapolation of the QCD results
from the accessible heavy-light meson masses to the B-meson mass is constrained
by the static result. The matching of the corresponding results in HQET and in
QCD is for the first time made at NLO accuracy in the MSbar(NDR)
renormalization scheme. All results are obtained in the quenched approximation.Comment: 27 pages (5 figures
Estimate of the chiral condensate in quenched lattice QCD
We determine the value of the quark condensate from quenched QCD simulations
on the lattice in two ways: (i) by using the GMOR formula; (ii) by comparing
the OPE prediction for the Goldstone pole contribution to the pseudoscalar
vertex, at moderately large momenta. In the MSbar scheme at mu=2 GeV, from the
GMOR formula we obtain = -(273 +/- 19 MeV)^3. We show that the value
extracted from the pseudoscalar vertex, = - (312 +/- 24 MeV)^3, is
consistent with the result obtained from the first (standard) method.Comment: 13 pages, 2 figures [version published in PLB
On internal structure of the heavy-light mesons
We compute the radial distributions of the vector and axial charge density as
well as of the matter density in the heavy-light mesons on the lattice. The
results for the lowest lying static heavy-light mesons and their first excited
counterparts are obtained with Nf=2 dynamical quarks of Wilson (Clover) type
and with the various improved static heavy quark actions. From these
distributions we were able to compute the corresponding charges and slopes of
the form factors (i.e. ). Those results are also presented, and briefly
discussed too.Comment: 31 page, 6 figures (published version
Impact of the finite volume effects on the chiral behavior of fK and BK
We discuss the finite volume corrections to fK and BK by using the one-loop
chiral perturbation theory in full, quenched, and partially quenched QCD. We
show that the finite volume corrections to these quantities dominate the
physical (infinite volume) chiral logarithms.Comment: 16 pages, 3 figures [published version
Chiral behavior of the B(s,d)-Bbar(s,d) mixing amplitude in the Standard Model and beyond
We compute the chiral logarithmic corrections to the Bd and Bs mixing
amplitudes in the Standard Model and beyond. We then investigate the impact of
the inclusion of the lowest-lying scalar heavy-light states to the decay
constants and bag-parameters and show that this does not modify the pion chiral
logarithms, but it does produce corrections which are competitive in size with
the K- and eta-meson chiral logarithms. This conclusion is highly relevant to
the lattice studies since the pion chiral logarithms represent the most
important effect in guiding the chiral extrapolations of the lattice data for
these quantities. Also important is to stress that the pion chiral logarithmic
corrections are useful in guiding those extrapolations as long as Mpi << Delta,
where Delta is the mass gap between the scalar and pseudoscalar heavy-light
mesons.Comment: 16 pages, 5 figures (published version
g(B*Bpi)-coupling in the static heavy quark limit
By means of QCD simulations on the lattice, we compute the coupling of the
heavy-light mesons to a soft pion in the static heavy quark limit. The gauge
field configurations used in this calculations include the effect of N_f=2
dynamical Wilson quarks, while for the static quark propagator we use its
improved form (so called HYP). On the basis of our results we obtain that the
coupling g=0.44 +/- 0.03 (+0.07/-0.00), where the second error is flat (not
gaussian).Comment: 7 pages, 3 figs (published version
On the mass differences between the scalar and pseudoscalar heavy-light mesons
We discuss the recent experimental observation which suggested that the mass
difference between the scalar and pseudoscalar heavy-light mesons is larger for
the non-strange states than for the strange ones. After computing the chiral
corrections in the heavy quark limit we show that, contrary to experiment, the
mass difference in the non-strange case should be smaller.Comment: 10 pages, 2 figure
Soft Photon Problem in Leptonic B-decays
We point out at the peculiarity of B --> mu nu decay, namely the enhancement
of the soft photon events which originate from the structure dependent part of
the B --> mu nu gamma amplitude. This may be a dominant source of systematic
uncertainty and compromise the projected experimental uncertainty on Gamma(B
--> mu nu). We show that the effect of these soft photons can be controlled if
the experimental cut on identification of soft photons is lowered and
especially if the better resolution in identifying the momentum of muon
emerging from B --> mu nu, is made. A lattice QCD computation of the relevant
form factors would be highly helpful for a better numerical control over the
structure dependent soft photon emission.Comment: 16 pages, 3 figure