Nucl.Phys.B598:57-72,2001 We investigate certain fixed points in the boundary conformal field theory
representation of type IIA D-branes on Gepner points of K3. They correspond
geometrically to ...degenerate brane configurations, and physically lead to
enhanced gauge symmetries on the world-volume. Non-abelian gauge groups arise
if the stabilizer group of the fixed points is realized projectively, which is
similar to D-branes on orbifolds with discrete torsion. Moreover, the fixed
point boundary states can be resolved into several irreducible components.
These correspond to bound states at threshold and can be viewed as (non-locally
free) sub-sheaves of semi-stable sheaves. Thus, the BCFT fixed points appear to
carry two-fold geometrical information: on the one hand they probe the boundary
of the instanton moduli space on K3, on the other hand they probe discrete
torsion in D-geometry.
Phys.Lett.B495:427-434,2000 Universal formulas for the boundary and crosscap coefficients are presented,
which are valid for all symmetric simple current modifications of the charge
conjugation ...invariant of any rational conformal field theory.
Phys.Lett.B651:102-107,2007 We report new precise p$(\vec{e},e^\prime p)\pi^0$ measurements at the peak
of the $\Delta^{+}(1232)$ resonance at $Q^2=\unit0.20(GeV/c)^2$ performed at
the Mainz ...Microtron (MAMI). The new data are sensitive to both the electric
quadrupole ($E2$) and the coulomb quadrupole ($C2$) amplitudes of the $\gamma^*
N\to\Delta$ transition. They yield precise quadrupole to dipole amplitude
ratios CMR $= (-5.09 \pm 0.28_{stat+sys}\pm 0.30_{model})%$ and EMR $= (-1.96
\pm 0.68_{stat+sys} \pm 0.41_{model})%$ for $M^{3/2}_{1+} = (39.57 \pm
0.75_{stat+sys}\pm 0.40_{model})(10^{-3}/m_{\pi^+})$. The new results are in
disagreement with Constituent Quark Model predictions and in qualitative
agreement with models that account for mesonic contributions, including recent
Lattice calculations. They thus give further credence to the conjecture of
deformation in hadronic systems favoring the attribution of the origin of
deformation to the dominance of mesonic effects.
Incompressible Quantum Hall fluids (QHF's) can be described in the scaling limit by three-dimensional topological field theories. Thanks to the correspondence between three-dimensional topological ...field theories and two dimensional chiral conformal field theories (CCFT's), we propose to study QHF's from the point of view of CCFT's. We derive consistency conditions and stability criteria for those CCFT's that can be expected to describe a QHF. A general algorithm is presented which uses simple currents to construct interesting examples of such CCFT's. It generalizes the description of QHF's in terms of Quantum Hall lattices. Explicit examples, based on the coset construction, provide candidates for the description of Quantum Hall fluids with Hall conductivity s_H=1/2 e^2/h, 1/4 e^2/h, 3/5 e^2/h, e^2/h,...
Eur.Phys.J.C50:535-538,2007 We report on the observation of a K$_s$p resonance signal at a mass of
1765$\pm$5 MeV/c$^2$, with intrinsic width $\Gamma = 108\pm 22$ MeV/c$^2$,
produced inclusively in ...$\Sigma^-$-nucleus interactions at 340 GeV/c in the
hyperon beam experiment WA89 at CERN. The signal was observed in the kinematic
region $x_F>0.7$, in this region its production cross section rises
approximately linearly with $(1-x_F)$, reaching $BR(X\to K_S p)\cdot d\sigma
/dx_F = (5.2\pm 2.3) \mu b $ per nucleon at $x_F=0.8$. The hard \xf spectrum
suggests the presence of a strong leading particle effect in the production and
hence the identification as a $\Sigma^{*+}$ state. No corresponding peaks were
observed in the $K^- p$ and $\Lambda \pi^{\pm}$ mass spectra.
58 NHL-patients (9 large cell centrocytic, 18 centroblastic, 16 immunoblastic, 15 lymphoblastic lymphomas) were treated immediately after diagnosis with CHOP-chemotherapy regardless of the extent of ...disease. Because of the advanced age of the majority of patients (median age 61 years, range 22-85 years) a reduced dose in the first two cycles was administered. Statistically significant prognostic variables influencing survival were the following: histologic subtypes according to the Kiel-classification (p less than 0,05), B-symptoms (p less than 0,001), blood sedimentation rate (p less than 0,02) and LDH (p less than 0,0005). With regard to prognosis there was no difference between patients over 60 years of age and younger ones (p less than 0,4). Patients achieving complete remission survived significantly longer (p less than 0,0001). Ann Arbor stages were of limited value, since patients with CS II disease and accumulation of risk factors (B-symptoms, abdominal disease, bulky tumor masses) showed a poorer outcome than patients with CS III who did not have these risk factors. A risk factor score summarizing features influencing prognosis is described and might be a useful tool in stratifying the heterogeneous group of NHL with unfavorable prognosis.
ECONF C0604032:0144,2006 The KaoS spectrometer at the Mainz Microtron MAMI, Germany, is perceived as
the ideal candidate for a dedicated spectrometer in kaon and hypernuclei
electroproduction. KaoS ...will be equipped with new read-out electronics, a
completely new focal plane detector package consisting of scintillating fibres,
and a new trigger system. First prototypes of the fibre detectors and the
associated new front-end electronics are shown in this contribution. The Mainz
hypernuclei research program will complement the hypernuclear experiments at
the planned FAIR facility at GSI, Germany. At the proposed antiproton storage
ring the spectroscopy of double Lambda hypernuclei is one of the four main
topics which will be addressed by the PANDA Collaboration. The experiments
require the operation of high purity germanium (HPGe) detectors in high
magnetic fields (B= 1T) in the presence of a large hadronic background. The
performance of high resolution Ge detectors in such an environment has been
investigated.
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