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In peripheral collisions of relativistic heavy ions highly excited spectators containing Lambda-hyperons can be produced. Such strange spectator matter may undergo a break-up into many fragments (multifragmentation) as it is well…

Nuclear Theory · Physics 2008-11-26 A. S. Botvina , J. Pochodzalla

A relativistic constituent quark model is used to calculate the semileptonic beta decay of nucleons and hyperons. The parameters of the model, namely, the constituent quark mass and the confinement scale, are fixed by a previous calculation…

High Energy Physics - Phenomenology · Physics 2011-08-17 Felix Schlumpf

We address an actual problem of baryon-resonance dominated meson-exchange processes in the low GeV regime, i.e. the phase and the structure of meson-NN* transition vertices. Our starting point is a quark-diquark model for the baryons…

Nuclear Theory · Physics 2008-11-26 M. Dillig , S. S. Rocha , G. F. Marranghello , E. F. Luetz , C. A. Z. Vasconcellos

The construction of baryonic operators for determining the N* excitation spectrum is discussed. The operators are designed with one eye towards maximizing overlaps with the low-lying states of interest, and the other eye towards minimizing…

High Energy Physics - Lattice · Physics 2014-11-17 LHP Collaboration , R. Edwards , R. Fiebig , G. Fleming , U. M. Heller , C. Morningstar , D. Richards , I. Sato , S. Wallace

The branching fractions of the semileptonic and rare $B_s$ decays are calculated in the framework of the QCD-motivated relativistic quark model. The form factors of the weak $B_s$ transitions are expressed through the overlap integrals of…

High Energy Physics - Phenomenology · Physics 2014-11-27 R. N. Faustov , V. O. Galkin

It is shown that the phenomenological description of the baryon magnetic moments in the quark model carries over to the Poincar\'e covariant extension of the model. This applies to all the three common forms of relativistic kinematics with…

High Energy Physics - Phenomenology · Physics 2009-11-10 B. Julia-Diaz , D. O. Riska

Baryonic excitation spectra, electroweak and strong decay properties are discussed within a relativistically covariant constituent quark model based on the instantaneous approximation to the three-body Bethe-Salpeter equation.

High Energy Physics - Phenomenology · Physics 2015-06-25 Bernard Metsch

Results for the proton and neutron electric and magnetic form factors as well as the nucleon axial form factor are presented for constituent quark models, based on either one-gluon-exchange and Goldstone-boson-exchange dynamics. The…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. F. Wagenbrunn , S. Boffi , L. Ya. Glozman , W. Klink , W. Plessas , M. Radici

In this paper scattering equivalences are used to simplify current operators in constituent quark models. The simplicity of the method is illustrated by applying it to a relativistic constituent quark model that fits the meson mass…

Nuclear Theory · Physics 2009-11-10 Evan Sengbusch , W. N. Polyzou

We report on a study of pi and eta decays of strange baryon resonances within relativistic constituent-quark models based on one-gluon-exchange and Goldstone-boson-exchange dynamics. The investigations are performed in the point form of…

Nuclear Theory · Physics 2008-11-26 T. Melde , W. Plessas , B. Sengl

The relativistic interacting quark-diquark model of baryons, recently developed, is here extended to introduce a spin-isospin transition interaction into the mass operator. The refined version of the model is used to calculate the non…

High Energy Physics - Phenomenology · Physics 2016-08-02 M. De Sanctis , J. Ferretti , E. Santopinto , A. Vassallo

We employ a model of nuclear structure that takes into account the quark substructure of the baryons to understand the behavior of static two-point correlation functions of meson fields in dense nuclear matter. We show that these…

Nuclear Theory · Physics 2025-09-23 Theo F. Motta , Gastão Krein

Weak $B^-\rightarrow D^0, \pi^0$ and $D^-\rightarrow {K}^0, \pi^0$ transition form factors are described in both the space- and time-like momentum transfer regions, within a constituent-quark model. Neutrino-meson scattering and…

High Energy Physics - Phenomenology · Physics 2022-02-09 Oliver Heger , María Gómez-Rocha , Wolfgang Schweiger

A Poincare-invariant description of mesonic baryon resonance decays is presented following the point form of relativistic quantum mechanics. In this contribution we focus on pionic decay modes. It is found that the theoretical results in…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. Melde , L. Canton , W. Plessas , R. F. Wagenbrunn

We present a relativistic point-form approach for the calculation of electroweak form factors of few-body bound states. As an example, the transition form factors for the semileptonic weak decay $B\to D^*e\bar \nu_e$ are discussed and it is…

High Energy Physics - Phenomenology · Physics 2012-11-06 María Gómez-Rocha , Wolfgang Schweiger

We study the influence of non-valence quark-pair contributions in weak transition form factors of heavy-light mesons. Form factors are first calculated for spacelike momentum transfers in a reference frame where such contributions are…

High Energy Physics - Phenomenology · Physics 2022-02-10 María Gómez-Rocha , Oliver Heger , Wolfgang Schweiger

Meson decays are considered within the constituent quark model, making use of the dispersion formulation of the model: Starting with spacelike momentum transfers $q$, meson transition form factors are expressed as relativistic invariant…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Melikhov

We present a microscopic derivation of the form factors of strong-interaction piNN and piNDelta vertices within a relativistic constituent quark model. The results are compared with form factors from phenomenological meson-baryon models and…

Nuclear Theory · Physics 2009-05-18 T. Melde , L. Canton , W. Plessas

Semileptonic and nonleptonic decays of the B_c meson to B_s and B mesons, caused by the c\to s,d quark transitions, are studied in the framework of the relativistic quark model. The heavy quark expansion in inverse powers of the active c…

High Energy Physics - Phenomenology · Physics 2011-03-23 D. Ebert , R. N. Faustov , V. O. Galkin

The general features of baryon form factors calculated with point form kinematics are derived. With point form kinematics and spectator currents hadronic form factors are functions of $\eta:={1\over 4}(v_{out}-v_{in})^2$ and, over a range…

Nuclear Theory · Physics 2015-06-26 F. Coester , D. O. Riska