Related papers: Algebraic Approach to Bare Nucleon Matrix Elements
We propose polynomial-time algorithms for finding nontrivial zeros of quadratic forms with four variables over rational function fields of characteristic 2. We apply these results to find prescribed quadratic subfields of quaternion…
A quark mass matrix model $M_q=M_e^{1/2} O_q M_e^{1/2} $ is proposed where $M_e^{1/2}={\rm diag}(\sqrt{m_e},\sqrt{m_\mu},\sqrt{m_\tau})$ and $O_q$ is a unit matrix plus a rank one matrix. Up- and down-quark mass matrices $M_u$ and $M_d$ are…
Quark-nuclear matter (QNM) is a many-body system containing hadrons and deconfined quarks. Starting from a microscopic quark-meson coupling (QMC) Hamiltonian with a density dependent quark-quark interaction, an effective quark-hadron…
Coulomb integrals, i.e., matrix elements of bare or screened Coulomb interaction between one-electron orbitals, are fundamental objects in many approaches developed to tackle the challenging problem of calculating the electronic structure…
We determine the strangeness and light quark fractions of the nucleon mass by computing the quark line connected and disconnected contributions to the matrix elements m_q <N|qbar q|N> in lattice QCD, using the non-perturbatively improved…
We investigate scalar matrix elements of the nucleon using $N_f=2+1+1$ flavors of maximally twisted mass fermions at a fixed value of the lattice spacing of $a\approx 0.078{\rm fm}$. We compute disconnected contributions to the relevant…
We consider matrix elements of two-nucleon operators that arise in chiral effective theories of the two-nucleon system. Generically, the short-distance piece of these operators scales as 1/r^n, with r the relative separation of the two…
The scalar heavy quark content of the nucleon, ${\cal M}_q = \bra{N} m_q \bar q q \ket{N},$ is relevant for computing the interaction of dark matter candidates with ordinary matter, while ${\cal M}_s$ is important for predicting the…
We study the nucleon matrix elements of the quark scalar-density operator using maximally twisted mass fermions with dynamical light ($u$,$d$), strange and charm degrees of freedom. We demonstrate that in this setup the nucleon matrix…
We compare recent theoretical determinations of weak matrix elements of the electroweak penguin operators Q7 and Q8. We pay special attention to the renormalization scheme dependence of these determinations as well as to the influence of…
The success of quantum physics in description of various physical interaction phenomena relies primarily on the accuracy of analytical methods used. In quantum mechanics, many of such interactions such as those found in quantum…
A review of methods for finding general expressions for matrix elements (non-diagonal with respect to configurations included) of any one- and two-particle operator for an arbitrary number of shells in an atomic configuration is given.…
Using the manifestly covariant spectator theory, and modeling the nucleon as a system of three constituent quarks with their own electromagnetic structure, we show that all four nucleon electromagnetic form factors can be very well…
The $B_K$ parameter is discussed in the general context of calculating beyond the factorization approximation for hadronic matrix elements. A variant of the $1/N_c$ method of Bardeen et al. is used. We present calculations within a low…
Interested in formalizing the generation of fast running code for linear algebra applications, the authors show how an index-free, calculational approach to matrix algebra can be developed by regarding matrices as morphisms of a category…
The accurate solution of some of the main problems in numerical linear algebra (linear system solving, eigenvalue computation, singular value computation and the least squares problem) for a totally positive Bernstein-Vandermonde matrix is…
Nonlinear equations are challenging to solve due to their inherently nonlinear nature. As analytical solutions typically do not exist, numerical methods have been developed to tackle their solutions. In this article, we give a quantum…
A dynamical quark model of hadron and nucleus structure is proposed. In the frame of the model, called the Strongly Correlated Quark Model, quarks and nucleons inside nuclei are arranged in a crystal--like structure.
Proton decay is one of possible signatures of baryon number violation, which has to exist to explain the baryon asymmetry and the existence of nuclear matter. Proton decays must be mediated through effective low-energy baryon number…
We study the non-singlet sectors of matrix quantum mechanics (MQM) through an operator algebra which generates the spectrum. The algebra is a nonlinear extension of the W_\infty algebra where the nonlinearity comes from the angular part of…