862 research outputs found

### Phenomenological research on professsional knowledge and educational relationship building

Following Dewey’s (1997) and Schwab’s (2013) ideas, Clandinin & Connelly (1992) developed
their notion of teacher as curriculum maker, it means, the “teacher not so much as a maker of
curriculum but as a part of it and to imagine a place for contexts, culture (Dewey´s notion of
interaction), and temporality (both past and future contained in Dewey´s notion of continuity)”
(p.365). In this way, teachers are not seen as implementers of curricular plans but as part of the
curriculum making process. In other words, they understand that students create their
curriculum in their experience at school when they interact with teachers and the environment.
Therefore, the educational relationship creates the framework where learning can take place
and students can build knowledge (Atkinson, 2015); it means, relationships generate meeting
places that allow the making and reshaping of curriculum.
If teaching takes place in the relationship, it means recognition (and acceptance) of the other
person, of the otherness. It supposes trying to come into relation with the other, and it implies
also acceptance of the uncertainty that otherness has. Therefore, education Is not about the
implementation of an education programme in order to achieve (pre)determined results. It is
not about intervention on students, but it is an experience of relationship where each one
constructs their own story (Molina, Blanco & Arbiol, 2016).
In short, curriculum is made through experiences that are lived in relation and, therefore, we
could say that education is an act of relationship (Piussi, 2006). In this way, education does not
require that teachers have the most appropriate knowledge and programme for every situation;
the educational experience is unpredictable and ineffable, we cannot anticipate or face it
completely (Van Manen, 2015). Thus, teaching requires becoming aware of how we build
relationships and how we see the other person (Contreras, 2002).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

### Meson-Baryon s-wave Resonances with Strangeness -3

Starting from a consistent SU(6) extension of the Weinberg-Tomozawa (WT)
meson-baryon chiral Lagrangian (Phys. Rev. D74 (2006) 034025), we study the
s-wave meson-baryon resonances in the strangeness S=-3 and negative parity
sector. Those resonances are generated by solving the Bethe-Salpeter equation
with the WT interaction used as kernel. The considered mesons are those of the
35-SU(6)-plet, which includes the pseudoscalar (PS) octet of pions and the
vector (V) nonet of the rho meson. For baryons we consider the 56-SU(6)-plet,
made of the 1/2+ octet of the nucleon and the 3/2+ decuplet of the Delta.
Quantum numbers I(J^P)=0(3/2^-) are suggested for the experimental resonances
Omega*(2250)- and Omega*(2380)-. Among other, resonances with I=1 are found,
with minimal quark content sss\bar{l}l', being s the strange quark and l, l'
any of the the light up or down quarks. A clear signal for such a pentaquark
would be a baryonic resonance with strangeness -3 and electric charge of -2 or
0, in proton charge units. We suggest looking for K- Xi- resonances with masses
around 2100 and 2240 MeV in the sector 1(1/2^-), and for pi Omega- and K- Xi*-
resonances with masses around 2260 MeV in the sector 1(3/2^-).Comment: 3 pages, 1 Postscript figure, 7 table

### Large Nc Weinberg-Tomozawa interaction and negative parity s--wave baryon resonances

It is shown that in the 70 and 700 SU(6) irreducible spaces, the SU(6)
extension of the Weinberg-Tomozawa (WT) s-wave meson-baryon interaction
incorporating vector mesons ({\it hep-ph/0505233}) scales as ${\cal O}(N_c^0)$,
instead of the well known ${\cal O}(N_c^{-1})$ behavior for its SU(3)
counterpart. However, the WT interaction behaves as order ${\cal O}(N_c^{-1})$
within the 56 and 1134 meson-baryon spaces. Explicit expressions for the WT
couplings (eigenvalues) in the irreducible SU(2$N_F$) spaces, for arbitrary
$N_F$ and $N_c$, are given. This extended interaction is used as a kernel of
the Bethe-Salpeter equation, to study the large $N_c$ scaling of masses and
widths of the lowest--lying negative parity s-wave baryon resonances.
Analytical expressions are found in the $N_c\to \infty$ limit, from which it
can be deduced that resonance widths and excitation energies $(M_R-M)$ behave
as order ${\cal O} (N^0_c)$, in agreement with model independent arguments, and
moreover they fall in the 70-plet, as expected in constituent quark models for
an orbital excitation. For the 56 and 1134 spaces, excitation energies and
widths grow ${\cal O} (N_c^{1/2})$ indicating that such resonances do not
survive in the large $N_c$ limit. The relation of this latter $N_c$ behavior
with the existence of exotic components in these resonances is discussed. The
interaction comes out repulsive in the 700.Comment: 21 pages, 3 figures, requires wick.sty and young.sty. Subsection
added. Conclusions revised. To appear in Physical Review

### Non-localities and Fermi motion corrections in $K^-$ atoms

We evaluate the p-wave $K^-N$ amplitudes from the chiral Lagrangians and from
there construct the p-wave part of the $K^-$ nucleus optical potential plus a
small s-wave part induced from the elementary p-wave amplitude and the nuclear
Fermi motion. Simultaneously, the momentum and energy dependence of the s-wave
optical potential, previously developed, are taken into account and shown to
generate a small p-wave correction to the optical potential. All the
corrections considered are small compared to the leading s-wave potential, and
lead to changes in the shifts and widths which are smaller than the
experimental errors.
A thorough study of the threshold region and low densities is conducted,
revealing mathematical problems for which a physical solution is given.Comment: revised version, 28 pages, Latex, 8 postscript figures. Submitted to
Nucl. Phys.

### D mesic nuclei

The energies and widths of several D^0 meson bound states for different
nuclei are obtained using a D-meson selfenergy in the nuclear medium, which is
evaluated in a selfconsistent manner using techniques of unitarized
coupled-channel theory. The kernel of the meson-baryon interaction is based on
a model that treats heavy pseudoscalar and heavy vector mesons on equal
footing, as required by heavy quark symmetry. We find D^0 bound states in all
studied nuclei, from 12C up to 208Pb. The inclusion of vector mesons is the
keystone for obtaining an attractive D-nucleus interaction that leads to the
existence of D^0-nucleus bound states, as compared to previous studies based on
SU(4) flavor symmetry. In some cases, the half widths are smaller than the
separation of the levels, what makes possible their experimental observation by
means of a nuclear reaction. This can be of particular interest for the future
PANDA@FAIR physics program. We also find a D^+ bound state in 12C, but it is
too broad and will have a significant overlap with the energies of the
continuum.Comment: 13 pages, 6 figures, 2 table

### Chiral Symmetry and s-wave Low-Lying Meson-Baryon Resonances

The $s-$wave meson-baryon scattering is analyzed for the isospin-strangeness
$I=1/2, S=0$ and $I=0,S=-1$ sectors, in a Bethe-Salpeter coupled channel
formalism incorporating Chiral Symmetry. For both sectors, four channels have
been considered: $\pi N$, $\eta N$, $K \Lambda$, $K \Sigma$ and $\pi \Sigma$,
$\bar K N$, $\eta \Lambda$, $K \Xi$, respectively. The needed two particle
irreducible matrix amplitudes are taken from lowest order Chiral Perturbation
Theory in a relativistic formalism. There appear undetermined low energy
constants, as a consequence of the renormalization of the amplitudes, which are
obtained from fits to the available data: elastic $\pi N$ phase-shifts, $\pi^-
p \to \eta n$ and $\pi^- p \to K^0 \Lambda$ cross sections and to
$\pi\Sigma\to\pi\Sigma$ mass-spectrum, the elastic $\bar K N \to \bar K N$ and
$\bar K N\to \pi \Sigma$ $t$--matrices and to the $K^- p \to \eta \Lambda$
cross section data. The position and residues of the complex poles in the
second Riemann sheet of the scattering amplitude determine masses, widths and
branching ratios of the $S_{11}-$ $N$(1535) and $-N$(1650) and $S_{01}-$
$\Lambda$(1405) and $-\Lambda$(1670) resonances, in reasonable agreement with
experiment. A good overall description of data, from threshold up to around 2
GeV is achieved despite the fact that three-body channels have not been
explicitly included.Comment: 5 Pages, 2 figures, invited contribution to Focus Session on Nature
of Threshold N*, to be published in Proceedings of Nstar 2002, Pittsburgh,
USA, October 9-12, 2002 (World Scientific

### Charmed hadrons in nuclear medium

We study the properties of charmed hadrons in dense matter within a
coupled-channel approach which accounts for Pauli blocking effects and meson
self-energies in a self-consistent manner. We analyze the behaviour in this
dense environment of dynamically-generated baryonic resonances as well as the
open-charm meson spectral functions. We discuss the implications of the
in-medium properties of open-charm mesons on the $D_{s0}(2317)$ and the
predicted X(3700) scalar resonances.Comment: 4 pages, 5 figures, invited parallel talk in the 5th International
Conference on Quarks and Nuclear Physics (QNP09), Beijing, September 21-26,
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