arXiv subjects

A. Dote

Publications and source records attributed to A. Dote.

9 recordsLinked to original sources

arXiv2019

Jump Markov Chains and Rejection-Free Metropolis Algorithms

We consider versions of the Metropolis algorithm which avoid the inefficiency of rejections. We first illustrate that a natural Uniform Selection Algorithm might not converge to the correct distribution. We then analyse the use of Markov jump chains which avoid successive repetitions of the same state. After exploring the properties of jump chains, we show how they can exploit parallelism in computer hardware to produce more efficient samples. We apply our results to the Metropolis algorithm, to Parallel Tempering, to a Bayesian model, to a two-dimensional ferromagnetic 4 x 4 Ising model, and to a pseudo-marginal MCMC algorithm.

math.ST↗

arXiv2015

Two, three, many body systems involving mesons. Multimeson condensates

In this talk we review results from studies with unconventional many hadron systems containing mesons: systems with two mesons and one baryon, three mesons, some novel systems with two baryons and one meson, and finally systems with many vector mesons, up to six, with their spins aligned forming states of increasing spin. We show that in many cases one has experimental counterparts for the states found, while in some other cases they remain as predictions, which we suggest to be searched in BESIII, Belle, LHCb, FAIR and other facilities.

hep-ph↗

arXiv2012

Narrow bound states of the DNN system

We report on a recent calculation of the properties of the $DNN$ system, a charmed meson with two nucleons. The system is analogous to the $\bar K NN$ system substituting a strange quark by a charm quark. Two different methods are used to evaluate the binding and width, the Fixed Center approximation to the Faddeev equations and a variational calculation. In both methods we find that the system is bound by about 200 MeV and the width is smaller than 40 MeV, a situation opposite to the one of the $\bar K NN$ system and which makes this state well suited for experimental observation.

nucl-th↗

arXiv2012

A narrow $DNN$ quasi-bound state

The energies and widths of $DNN$ quasi-bound states with isospin I=1/2 are evaluated in two methods, the fixed center approximation to the Faddeev equation and the variational method approach to the effective one-channel Hamiltonian. The $DN$ interactions are constructed so that they dynamically generate the $Λ_c(2595)$ (I=0, $J^π =1/2^-$) resonance state. We find that the system is bound by about 250 MeV from the $DNN$ threshold, $\sqrt{s} \sim 3500$ MeV. Its width including both the mesonic decay and the $D$ absorption, is estimated to be about 20-40 MeV. The I=0 $DN$ pair in the $DNN$ system is found to form a cluster that is similar to the $Λ_c(2595)$.

hep-ph↗

arXiv2005

Strange tribaryons as Kbar-mediated dense nuclear systems

We discuss the implications of recently discovered strange tribaryons in 4He(stopped-K-, p)S0 (3115) and 4He(stopped-K, n) S1 (3140) within the framework of deeply bound kbar states formed on shrunk nuclear cores. S1 (3140) corresponds to T=0 ppnK-, whereas S0 (3115) to T=1 pnnK-, which is an isobaric analog state of pppK-, predicted previously. The observed binding energies can be accounted for by including the relativistic effect and by invoking a medium-enhanced kbar-N interaction by 15%. We propose various experimental methods to further study these and related bound systems.

nucl-th↗

arXiv2002

High-density K nuclear systems with isovector deformation

Using a phenomenological KN potential which reproduces $Λ$(1405) as an I=0 bound state of KN, we investigated deeply bound kaonic nuclei, ppnK$^-$ and $^8$BeK$^-$, with the method of Antisymmetrized Molecular Dynamics. Our calculations show that strongly bound kaonic nuclear systems with unusual exotic structures are formed around the K$^-$, which attracts the surrounding nucleons to an extremely high-density assembly and induces a proton-neutron separation, ``isovector deformation''.

nucl-th↗

arXiv2002

Structures and Transitions in Light Unstable Nuclei

We study the structures of the unstable Be isotopes with the theoretical method of antisymmetrized molecular dynamics. It is found that various structures of the excited states appear in the low-energy region of neutron-rich Be nuclei. Focusing on the 2$α$ clustering, we analyze the intrinsic structures with the help of the experimental data of Gamow-Teller transitions.

nucl-th↗

arXiv1999

Structure of Excited States of 10Be studied with Antisymmetrized Molecular Dynamics

We study structure of excited states of 10Be with the method of variation after spin parity projection in the framework of antisymmetrized molecular dynamics. Present calculations describe many excited states and reproduce the experimental data of E2 and E1 transitions and the new data of the $β$ transition strength successfully. We make systematic discussions on the molecule-like structures of light unstable nuclei and the important role of the valence neutrons based on the results obtained with the framework which is free from such model assumptions as the existence of inert cores and clusters.

nucl-th↗

arXiv1997

AMD + HF model and its application to Be isotopes

In order to study light unstable nuclei systematically, we propose a new method ''AMD + Hartree-Fock''. This method introduces the concept of the single particle orbits into the usual AMD. Applying AMD + HF to Be isotopes, it is found that the calculated lowest intrinsic states with plus and minus parities have rather good correspondence with the explanation by the two-center shell model. In addition, by active use of the single particle orbits extracted from AMD wave function, we construct the first excited 0^+ state of $^{10}$Be. The obtained state appears in the vicinity of the lowest 1^- state. This result is consistent with the experimental data.

nucl-th↗