Nuclear Theory·nucl-th

Thursday·July 2, 2015

6 papers—3 primary·3 cross-listed

01
Collective inertia of Nambu-Goldstone mode from linear response theory
Nobuo Hinohara
Background: Spurious zero-energy Nambu-Goldstone (NG) modes appear when the symmetry of a system is spontaneously broken. The Thouless-Valatin inertia, the collective inertia of the NG mode, contains important information concerning collective motion. Purpose: To establish an efficient and precise method for deriving the collective inertia and the conjugate operator of a NG mode, we derive an expression for the response function in terms of the coordinate-momentum representation of the quasiparticle random-phase approximation which is valid even if a symmetry-restoring zero-energy mode is present. Methods: We use the finite amplitude method for computing the response function of superfluid nuclei with the nuclear density functional theory. Results: We derived analytically the collective inertia and the conjugate coordinate operator of the NG mode from the zero-energy linear response with the momentum operator of the NG mode. The formulation is tested in the cases of translational and pairing rotational modes. Illustrative calculations are performed for the neutron pairing rotation in Sn isotopes, the proton pairing rotation in N = 82 isotones, and the neutron and proton pairing rotations around the 130Xe nucleus. Conclusions: The proposed formulation allows us to compute the collective inertia of the NG mode precisely and efficiently. The conjugate coordinate operator can be utilized to remove spurious contributions to the strength distribution in the finite amplitude method.
nucl-thPRC(2015)·35 citations
02
The radiative 10Be(n,g)11be capture at thermal and astrophysical energies
S.B. Dubovichenko · A.V. Dzhazairov-Kakhramanov
Within the framework of the modified potential cluster model with the forbidden states and the classification of states according to Young tableaux the possibility of describing the available experimental data for the total reaction cross sections of the neutron radiative capture on 10Be at thermal and astrophysical energies was shown.
nucl-thJ.Phys.G(2016)·6 citations
03
Advanced density matrix renormalization group method for nuclear structure calculations
Ö. Legeza · L. Veis · A. Poves · J. Dukelsky
We present an efficient implementation of the Density Matrix Renormalization Group (DMRG) algorithm that includes an optimal ordering of the proton and neutron orbitals and an efficient expansion of the active space utilizing various concepts of quantum information theory. We first show how this new DMRG methodology could solve a previous $400$ KeV discrepancy in the ground state energy of $^{56}$ Ni. We then report the first DMRG results in the $p f + g 9/2$ shell model space for the ground $0^{+}$ and first $2^{+}$ states of $^{64}$ Ge which are benchmarked with reference data obtained from Monte Carlo shell model. The corresponding correlation structure among the proton and neutron orbitals is determined in terms of the two-orbital mutual information. Based on such correlation graphs we propose several further algorithmic improvement possibilities that can be utilized in a new generation of tensor network based algorithms.
nucl-thcond-mat.str-elphysics.chem-phPRC(2015)·62 citations
04
Bottomonium Mesons and Strategies for Their Observation
Stephen Godfrey🇨🇦 · Kenneth Moats (Carleton University)🇨🇦
The $B$ -factories and Large Hadron Collider experiments have demonstrated the ability to observe and measure the properties of bottomonium mesons. In order to discover missing states it is useful to know their properties to develop a successful search strategy. To this end we calculate the masses and decay properties of excited bottomonium states. We use the relativized quark model to calculate the masses and wavefunctions and the $^{3} P_{0}$ quark-pair creation model to calculate decay widths to open bottom. We also summarize results for radiative transitions, annihilation decays, hadronic transitions and production cross sections which are used to develop strategies to find these states. We find that the $b b ˉ$ system has a rich spectroscopy that we expect to be substantially extended by the LHC and $e^{+} e^{-}$ experiments in the near future. Some of the most promising possibilities at the LHC are observing the $χ_{b (1, 2)} (3 P)$ , $χ_{b (1, 2)} (4 P)$ and $η_{b} (3 S)$ states in $γ μ^{+} μ^{-}$ final states that proceed via radiative transitions through $Υ (n S)$ intermediate states and $1^{3} D_{J}$ and $2^{3} D_{J}$ into $γ γ μ^{+} μ^{-}$ final states proceeding via $1^{3} P_{J} \to 1^{3} S_{1}$ and $2^{3} P_{J} \to 2^{3} S_{1}$ intermediate states respectively. Some of the most interesting possibilities in $e^{+} e^{-}$ collisions are studying the $1^{3} D_{J}$ states via $4 γ$ cascades starting with the $Υ (3 S)$ and the $3^{3} P_{J}$ states in $γ γ μ^{+} μ^{-}$ final states starting with the $Υ (4 S)$ and proceeding via $Υ (n S)$ intermediate states. Completing the bottomonium spectrum is an important validation of lattice QCD calculations and a test of our understanding of bottomonium states in the context of the quark model.
↳ hep-phhep-exnucl-exnucl-thPRD(2015)·183 citations
05
Neutrinoless Double Beta Decay
Heinrich Päs🇩🇪 · Werner Rodejohann🇩🇪
We review the potential to probe new physics with neutrinoless double beta decay $(A, Z) \to (A, Z + 2) + 2 e^{-}$ . Both the standard long-range light neutrino mechanism as well as short-range mechanisms mediated by heavy particles are discussed. We also stress aspects of the connection to lepton number violation at colliders and the implications for baryogenesis.
↳ hep-phhep-exnucl-exnucl-thNew J.Phys.(2015)·153 citations
06
Configuration Mixing of Quark States in Baryons
B. Saghai🇫🇷 · Z. Li🇺🇸
Mixing angles are used to describe the $S U (6) \otimes O (3)$ symmetry breaking in $[70, 1^{-}]$ multiplet in the sector of the lowest mass nucleon resonances, which are investigated extensively in constituent quark models for baryon spectroscopy. The transition amplitudes for the meson photoproduction off nucleon can also be expressed in terms of the mixing angles to take into account the configuration mixing. Those amplitudes are derived as a function of the mixing angles between $∣ N^{2} P_{M} J^{-} ⟩$ and $∣ N^{4} P_{M} J^{-} ⟩$ states, with $J$ =1/2 and 3/2, for the processes $γ p \to η p, K^{+} Λ, K^{+} Σ^{\circ}, K^{\circ} Σ^{+}$ . The present status of our knowledge on the mixing angles between $S_{11} (1535)$ and $S_{11} (1650)$ ( $θ_{S}$ ), as well as between $D_{13} (1520)$ and $D_{13} (1700)$ ( $θ_{D}$ ) is reported. Since these resonances play very important role in the threshold region for both $η$ and kaon production mechanisms, they are expected to provide crucial tests of different quark models for the baryon spectroscopy.
↳ hep-phnucl-thFew Body Syst.(2010)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE

Collective inertia of Nambu-Goldstone mode from linear response theory

The radiative 10Be(n,g)11be capture at thermal and astrophysical energies

Advanced density matrix renormalization group method for nuclear structure calculations

Bottomonium Mesons and Strategies for Their Observation

Neutrinoless Double Beta Decay

Configuration Mixing of Quark States in Baryons

Affiliations