Nuclear Theory·nucl-th

Tuesday·December 8, 2015

13 papers—7 primary·6 cross-listed

08
SMWDs as SGRs/AXPs and the lepton number violation
J. Adam Jr.🇨🇿 · V.B. Belyaev🇷🇺 · P. Ricci🇮🇹 · F. Šimkovic🇷🇺 · E. Truhlík🇨🇿
Possible nature of strongly magnetized white dwarfs (SMWDs) is studied. It is shown that for relatively low values of the equatorial surface magnetic field $B \sim 1 0^{9} - 1 0^{11}$ G they can be good candidates for soft gamma-ray repeaters and anomalous X-ray pulsars (SGRs/AXPs). For the case of iron SMWDs the influence of a neutrinoless electron to positron conversion on the SGRs/AXPs luminosity is estimated.
↳ astro-ph.SRastro-ph.HEnucl-thAIP Conf.Proc.(2015)·0 citations
09
Kinetic theory of spin-polarized systems in electric and magnetic fields with spin-orbit coupling: I. Kinetic equation and anomalous Hall and spin-Hall effects
K. Morawetz
The coupled kinetic equation for density and spin Wigner functions are derived including spin-orbit coupling, electric and magnetic field as well as selfconsistent Hartree meanfields suited for SU(2) transport. The interactions are assumed to be with scalar and magnetic impurities as well as scalar and spin-flip potentials among the particles. The spin-orbit interaction is used in a form suitable to solid state physics with Rashba or Dresselhaus coupling, graphene, extrinsic spin-orbit coupling as well as effective nuclear matter coupling. The deficiencies of the two-fluid model are worked out consisting in the appearance of an effective in-medium spin-precession. The stationary solution of all these systems shows a band splitting controlled by an effective medium-dependent Zeeman field. The selfconsistent precession direction is discussed and a cancellation of linear spin-orbit coupling at zero temperature is reported. The precession of spin around this effective direction caused by spin-orbit coupling leads to anomalous charge and spin currents in an electric field. Anomalous Hall conductivity is shown to consists of the known results obtained from Kubo formula or Berry phases and a new symmetric part interpreted as inverse Hall effect. Analogously the spin-Hall and inverse spin-Hall effect of spin currents are discussed which are present even without magnetic fields showing a spin accumulation triggered by currents. The analytical dynamical expressions for zero temperature are derived and discussed in dependence on the magnetic field and effective magnetizations. The anomalous Hall and spin-Hall effect changes sign at higher than a critical frequency dependent on the relaxation time.
↳ cond-mat.str-elcond-mat.mes-hallmath-phmath.MP+2PRB(2015)·9 citations
10
Kinetic theory of spin-polarized systems in electric and magnetic fields with spin-orbit coupling: II. RPA response functions and collective modes
K. Morawetz
The spin and density response functions in the random phase approximation (RPA) are derived by linearizing the kinetic equation including a magnetic field, the spin-orbit coupling, and mean fields with respect to an external electric field. Different polarization functions appear describing various precession motions showing Rabi satellites due to an effective Zeeman field. The latter turns out to consist of the mean-field magnetization, the magnetic field, and the spin-orbit vector. The collective modes for charged and neutral systems are derived and a threefold splitting of the spin waves dependent on the polarization and spin-orbit coupling is shown. The dielectric function including spin-orbit coupling, polarization and magnetic fields is presented analytically for long wave lengths and in the static limit. The dynamical screening length as well as the long-wavelength dielectric function shows an instability in charge modes, which are interpreted as spin segregation and domain formation. The spin response describes a crossover from damped oscillatory behavior to exponentially damped behavior dependent on the polarization and collision frequency. The magnetic field causes ellipsoidal trajectories of the spin response to an external electric field and the spin-orbit coupling causes a rotation of the spin axes. The spin-dephasing times are extracted and discussed in dependence on the polarization, magnetic field, spin-orbit coupling and single-particle relaxation times.
↳ cond-mat.str-elcond-mat.mes-hallmath-phmath.MP+2PRB(2015)·2 citations
11
Strong decay patterns of the hidden-charm tetraquarks
Li Ma🇨🇳 · Wei-Zhen Deng🇨🇳 · Xiao-Lin Chen🇨🇳 · Shi-Lin Zhu🇨🇳
With the spin rearrangement, we have performed a comprehensive investigation of the decay patterns of the S-wave tetraquarks and P-wave tetraquarks where the P-wave excitation exists either between the diquark and anti-diquark pair or inside the diquark. Especially, we compare the decay patterns of $Y (4260)$ with different inner structures such as the conventional charmonium, the molecule, the P-wave tetraquark and the hybrid charmonium. We notice the $J / ψ π π$ mode is suppressed in the heavy quark symmetry limit if $Y (4260)$ is a molecular state. Moreover the hybrid charmonium and hidden-charm tetraquark have very similar decay patterns. Both of them decay into the $J / ψ π π$ and open charm modes easily. We also discuss the decay patterns of $X (3872)$ , $Y (4360)$ , and several charged states such as $Z_{c} (4020)$ . The $h_{c} π^{\pm}$ decay mode disfavors the tetraquark assumption of $Z_{c} (4020)$ .
↳ hep-phhep-exhep-latnucl-th9 citations
12
Observation of the Efimov state of the helium trimer
Maksim Kunitski · Stefan Zeller · Jörg Voigtsberger · Anton Kalinin · Lothar Ph. H. Schmidt · Markus Schöffler · Achim Czasch · Wieland Schöllkopf · Robert E. Grisenti · Till Jahnke · Dörte Blume · Reinhard Dörner
Quantum theory dictates that upon weakening the two-body interaction in a three-body system, an infinite number of three-body bound states of a huge spatial extent emerge just before these three-body states become unbound. Three helium atoms have been predicted to form a molecular system that manifests this peculiarity under natural conditions without artificial tuning of the attraction between particles by an external field. Here we report experimental observation of this long predicted but experimentally elusive Efimov state of $^{4}$ He $_{3}$ by means of Coulomb explosion imaging. We show spatial images of an Efimov state, confirming the predicted size and a typical structure where two atoms are close to each other while the third is far away.
↳ physics.atm-cluscond-mat.quant-gasnucl-exnucl-th+1Science(2015)·110 citations
13
Enhanced spin-dependent parity non-conservation effect in the $7 s^{2} S_{1/2} \to 6 d^{2} D_{5/2}$ transition in Fr: A possibility for unambiguous detection of nuclear anapole moment
B. K. Sahoo · T. Aoki · B. P. Das · Y. Sakemi
Employing the relativistic coupled-cluster method, comparative studies of the parity non-conserving electric dipole amplitudes for the $7 s^{2} S_{1/2} \to 6 d^{2} D_{5/2}$ transitions in $^{210}$ Fr and $^{211}$ Fr isotopes have been carried out. It is found that these transition amplitudes, sensitive only to the nuclear spin dependent effects, are enhanced by more than 3 orders compared to the low-lying $S - D_{5/2}$ transitions in Ba $^{+}$ and Ra $^{+}$ owing to the very large contributions from the electron core-polarization effects in Fr. This translates to a relatively large and, in principle, measurable induced light shift, which would be a signature of nuclear spin dependent parity nonconservation that is dominated by the nuclear anapole moment in a heavy atom like Fr. A plausible scheme to measure this quantity using the Cyclotron and Radioisotope Center (CYRIC) facility at Tohoku University has been outlined.
↳ physics.atom-phnucl-thphysics.comp-phphysics.opticsPRA(2016)·15 citations

Affiliations

first authorsco-authorsvia INSPIRE

SMWDs as SGRs/AXPs and the lepton number violation

Kinetic theory of spin-polarized systems in electric and magnetic fields with spin-orbit coupling: I. Kinetic equation and anomalous Hall and spin-Hall effects

Kinetic theory of spin-polarized systems in electric and magnetic fields with spin-orbit coupling: II. RPA response functions and collective modes

Strong decay patterns of the hidden-charm tetraquarks

Observation of the Efimov state of the helium trimer

Enhanced spin-dependent parity non-conservation effect in the 7s2S1/2​→6d2D5/2​ transition in Fr: A possibility for unambiguous detection of nuclear anapole moment

Affiliations

Enhanced spin-dependent parity non-conservation effect in the $7 s^{2} S_{1/2} \to 6 d^{2} D_{5/2}$ transition in Fr: A possibility for unambiguous detection of nuclear anapole moment