Related papers: N* Spectrum using an O(a)-Improved Fermion Action
The parity doublet model, containing the SU(2) multiplets including the baryons identified as the chiral partners of the nucleons is applied to neutron stars. The maximum mass for the star is calculated for different stages of the cooling…
In this work, we outline the findings of our recent study of the properties of $N^*(1895)$ and its consequential impacts on the cross sections of the photoproduction of $\Lambda(1405)$. Further, we discuss the possibility of the existence…
We present one-loop matching coefficients between continuum and lattice QCD for the heavy-light four-fermion operators relevant for neutral B meson mixing both within and beyond the Standard Model. For the lattice theory we use…
In this work a mass model based on a SO(10) GUT with a global U(1) family symmetry is discussed which leads to an asymmetric Nearest Neighbour Interaction structure for the fermionic mass matrices. As a result of the analysis one gets three…
We compute the O(\alpha_s^2) contributions to the photon energy spectrum of the inclusive decay \bar{B} -> X_s \gamma associated with the magnetic penguin operator O_7. They are an essential part of the ongoing NNLO calculation of this…
A scaling hypothesis for the n-particle spectral densities of the O(3) nonlinear sigma-model is described. It states that for large particle numbers the n-particle spectral densities are ``self-similar'' in being basically rescaled copies…
A new approach of the QCD sum rule is proposed in which positive and negative-parity baryons couple with each other. With positive and negative-parity states explicitly taken into account, sum rules are derived by means of the dispersion…
A method is formulated for the description of lambda hypernuclei in the framework of the unitary-model-operator approach (UMOA). The method is applied to $_{\Lambda}^{17}$O. A lambda-nucleon effective interaction is derived, taking the…
We study the coupling of the Lambda(1520)= Lambda* resonance to the \bar K* vector meson and nucleon. This coupling is not directly measured from the resonance decay, but is expected to be important in hyperon production reactions, in…
We present first results from a simulation of quenched overlap fermions with improved gauge field action. Among the quantities we study are the spectral properties of the overlap operator, the chiral condensate and topological charge, quark…
Pairing gaps for fermionic atoms in harmonic oscillator traps are calculated for a wide range of interaction strengths and particle number, and compared to pairing in nuclei. Especially systems, where the pairing gap exceeds the level…
We compute the ratio Lambda_L/Lambda_MS, where the scale parameter Lambda_L is associated with a lattice formulation of QCD. We consider a 3-parameter family of gluon actions, which are most frequently used for O(a) improvement a` la…
We present a calculation of nuclear matter which goes beyond the usual quasi-particle approximation in that it includes part of the off-shell dependence of the self-energy in the self-consistent solution of the single-particle spectrum. The…
An new method of calculating the energy spectrum of neutrinos and antineutrinos produced in the electron-positron annihilation processes in hot stellar plasma is presented. Detection of these neutrinos, produced copiously in the…
We improve so called ``naive'' and ``mirror'' models for the positive and negative parity nucleons, $N$ and $N^{*}$, by introducing nonlinear terms allowed by chiral symmetry. Both models in this improvement reproduce the observed nucleon…
New limits on couplings $\lambda^i_{jk}{''}$, which break both the baryon number and the $R$--parity, are derived by using a new mechanism that contributes to the neutron-anti-neutron oscillation. The constraints due to proton decay and its…
The Random Phase Approximation theory is used to calculate the total cross sections of electron neutrinos on $^{12}$C nucleus. The role of the excitation of the discrete spectrum is discussed. A comparison with electron scattering and muon…
The cross section for n+p -> d+gamma is calculated at energies relevant to big bang nucleosynthesis using the recently developed effective field theory that describes the two-nucleon sector. The E1 amplitude is computed up to NNNLO and…
This thesis is dedicated to explore the feasibility of numerical calculations in the $\epsilon$--regime of QCD for the extraction of physical information. We apply two formulations of the Ginsparg-Wilson fermions the Neuberger operator and…
At future e+- e- linear colliders, the event rates and clean signals of scalar fermion production - in particular for the scalar leptons - allow very precise measurements of their masses and couplings and the determination of their quantum…