Nuclear Theory·nucl-th

Wednesday·July 8, 2015

9 papers—4 primary·5 cross-listed

01
Thermal Resonance Fusion
Bao-Guo Dong
We first show a possible mechanism to create a new type of nuclear fusion, thermal resonance fusion, i.e. low energy nuclear fusion with thermal resonance of light nuclei or atoms, such as deuterium or tritium. The fusion of two light nuclei has to overcome the Coulomb barrier between these two nuclei to reach up to the interacting region of nuclear force. We found nuclear fusion could be realized with thermal vibrations of crystal lattice atoms coupling with light atoms at low energy by resonance to overcome this Coulomb barrier. Thermal resonances combining with tunnel effects can greatly enhance the probability of the deuterium fusion to the detectable level. Our low energy nuclear fusion mechanism research - thermal resonance fusion mechanism results demonstrate how these light nuclei or atoms, such as deuterium, can be fused in the crystal of metal, such as Ni or alloy, with synthetic thermal vibrations and resonances at different modes and energies experimentally. The probability of tunnel effect at different resonance energy given by the WKB method is shown that indicates the thermal resonance fusion mode, especially combined with the tunnel effect, is possible and feasible. But the penetrating probability decreases very sharply when the input resonance energy decreases less than 3 keV, so for thermal resonance fusion, the key point is to increase the resonance peak or make the resonance sharp enough to the acceptable energy level by the suitable compound catalysts, and it is better to reach up more than 3 keV to make the penetrating probability larger than 10^{-10}.
nucl-th0 citations
02
Shear viscosity of pionic and nucleonic components from their different possible mesonic and baryonic thermal fluctuations
Sabyasachi Ghosh🇧🇷
Owing to the Kubo relation, the shear viscosities of pionic and nucleonic components have been evaluated from their corresponding retarded correlators of viscous stress tensor in the static limit, which become non-divergent only for the non-zero thermal widths of the constituent particles. In the real-time thermal field theory, the pion and nucleon thermal widths have respectively been obtained from the pion self-energy for different meson, baryon loops and the nucleon self-energy for different pion-baryon loops. We have found a non-monotonic momentum distributions of pion and nucleon thermal widths, which have been integrated out by their respective Bose-enhanced and Pauli-blocked phase space factors during evaluation of their shear viscosities. The viscosity to entropy density ratio for this mixed gas of pion-nucleon system decreases and approaches toward its lower bound as the temperature and baryon chemical potential increase within the relevant domain of hadronic matter.
nucl-thhep-phBraz.J.Phys.(2015)·15 citations
03
Thermal conductivity of hot pionic medium due to pion self-energy for $π σ$ and $π ρ$ loops
Sabyasachi Ghosh🇧🇷
The thermal conductivity of pionic medium has been evaluated with the help of its standard expression from the relaxation time approximation, where inverse of pion relaxation time or pion thermal width has been obtained from the imaginary part of pion self-energy. In the real-time formalism of thermal field theory, the finite temperature calculations of pion self-energy for $π σ$ and $π ρ$ loops have been done. The numerical value of our thermal conductivity increases with temperature very softly, though at particular temperature, our estimation has to consider a large band of phenomenological uncertainty.
nucl-thhep-phIJMPE(2015)·6 citations
04
Capture reactions into borromean two-proton systems at rp-waiting points
D. Hove · A.S. Jensen · H.O.U. Fynbo · N.T. Zinner · D.V. Fedorov · E. Garrido
We investigate even-even two-proton borromean systems at prominent intermediate heavy waiting points for the rapid proton capture process. The most likely single-particle levels are used to calculate three-body energy and structure as a function of proton-core resonance energy. We establish a linear dependence between two- and three-body energies with the same slope, but the absolute value slightly dependent on partial wave structure. Using these relations we predict low-lying excited states in the isotones following the critical waiting points. The capture rate for producing a borromean bound state is described both based on a full three-body calculation and on a very simple analytic rate expression for temperatures about $1 - 5$ ~GK. This rate is valid for both direct and sequential capture paths, and it only depends on the three-body resonance energy. As a result the relevant path of the radiative capture reactions can be determined. We present numerical results for $E 1$ and $E 2$ photon emission, and discuss occurrence preferences in general as well as relative sizes of these most likely processes. Finally, we present narrow estimated intervals for the proton capture rates relevant for the critical waiting points.
nucl-thastro-ph.HEPRC(2016)·9 citations
05
The role of spin-flipping terms in hadronic transitions of $Υ (4 S)$
Jorge Segovia🇪🇸 · Francisco Fernandez🇪🇸 · David R. Entem🇪🇸
Recent experimental data on the $Υ (4 S) \to Υ (1 S) η$ and $Υ (4 S) \to h_{b} (1 P) η$ processes seem to contradict the naive expectation that hadronic transitions with spin-flipping terms should be suppressed with respect those without spin-flip. We analyze these transitions using the QCD Multipole Expansion (QCDME) approach and within a constituent quark model framework that has been applied successfully to the heavy-quark sectors during the last years. The QCDME formalism requires the computation of hybrid intermediate states which has been performed in a natural, parameter-free extension of our constituent quark model based on the Quark Confining String (QCS) scheme. We show that i) the M1-M1 contribution in the decay rate of the $Υ (4 S) \to Υ (1 S) η$ is important and its supression until now is not justified; ii) the role played by the $L = 0$ hybrid states, which enter in the calculation of the M1-M1 contribution, explains the enhancement in the $Υ (4 S) \to Υ (1 S) η$ decay rate; and iii) the anomalously large decay rate of the $Υ (4 S) \to h_{b} (1 P) η$ process has the same physical origin.
↳ hep-phhep-exnucl-thFew Body Syst.(2016)·9 citations
06
Universality of multiplicity distribution in proton-proton and electron-positron collisions
Adam Bzdak🇵🇱
It is argued that the multiplicity distribution in proton-proton ( $pp$ ) collisions, which is often parameterized by the negative binomial distribution, may result from the multiplicity distribution measured in electron-positron ( $e^{+} e^{-}$ ) collisions, once the fluctuating energy carried by two leading protons in $pp$ is taken into account.
↳ hep-phhep-exnucl-exnucl-thPRD(2017)·5 citations
07
Searching for observable effects induced by anomalous triangle singularities
Xiao-Hai Liu🇯🇵 · Makoto Oka🇯🇵 · Qiang Zhao🇨🇳
We investigate the anomalous triangle singularity (ATS) and its possible manifestations in various processes. We show that the ATS should have important impact on our understanding of the nature of some newly observed threshold states. Discussions on how to distinguish the ATS phenomena from genuine dynamic pole structures are presented.
↳ hep-phhep-exnucl-exnucl-thPLB(2016)·146 citations
08
Strange particles production in relativistic nucleus-nucleus collisions at the RHIC BES energy region
Cong-Cong Zhang🇨🇳 · Xian-Bao Yuan🇨🇳 · Sheng-Qin Feng🇨🇳 · Zhong-Bao Yin🇨🇳
The parton and hadron cascade model PACIAE is used to investigate strange particle production in Au + Au collisions at GeV in different centralities and at 39, 11.5 and 7.7 GeV in the most central collision, respectively. It is shown that the transverse momentum distributions of strange particles by the PACIAE model fit the RHIC Beam Energy Scan experimental results well.
↳ hep-phnucl-thCPC(2016)·0 citations
09
On the Implementation of General Background Electromagnetic Fields on a Periodic Hypercubic Lattice
Zohreh Davoudi🇺🇸 · William Detmold🇺🇸
Nonuniform background electromagnetic fields, once implemented in lattice quantum chromodynamics calculations of hadronic systems, provide a means to constrain a large class of electromagnetic properties of hadrons and nuclei, from their higher electromagnetic moments and charge radii to their electromagnetic form factors. We show how nonuniform fields can be constructed on a periodic hypercubic lattice under certain conditions and determine the precise form of the background U(1) gauge links that must be imposed on the quantum chromodynamics gauge-field configurations to maintain periodicity. Once supplemented by a set of quantization conditions on the background-field parameters, this construction guarantees that no nonuniformity occurs in the hadronic correlation functions across the boundary of the lattice. The special cases of uniform electric and magnetic fields, a nonuniform electric field that varies linearly in one spatial coordinate (relevant to the determination of quadruple moment and charge radii), nonuniform electric and magnetic fields with given temporal and spatial dependences (relevant to the determination of nucleon spin polarizabilities) and plane-wave electromagnetic fields (relevant to the determination of electromagnetic form factors) are discussed explicitly.
↳ hep-lathep-phnucl-thPRD(2015)·21 citations

Affiliations

first authorsco-authorsvia INSPIRE