Nuclear Theory·nucl-th

Thursday·May 7, 2015

8 papers—4 primary·4 cross-listed

01
[Submitted on 6 May 2015]
A new renormalization procedure of the quasiparticle random phase approximation
A. A. Raduta · C. M. Raduta
The ground state of a many body Hamiltonian considered in the quasiparticle representation is redefined by accounting for the quasiparticle quadrupole pairing interaction. The residual interaction of the newly defined quasiparticles is treated by the QRPA. Solutions of the resulting equations exhibit specific features. In particular, there is no interaction strength where the first root is vanishing. A comparison with other renormalization methods is presented.
Comments:
16 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1505.01339 [pdf]
IJMPE(2016)·2 citations
02
[Submitted on 6 May 2015]
Three-body bremsstrahlung and the rotational character of the 12C-spectrum
E. Garrido · A.S. Jensen · D.V. Fedorov
The electric quadrupole transitions between $0^{+}$ , $2^{+}$ , and $4^{+}$ states in $^{12}$ C are investigated in a $3 α$ model. The three-body wave functions are obtained by means of the hyperspherical adiabatic expansion method, and the continuum is discretized by imposing a box boundary condition. Corresponding expressions for the continuum three-body ( $3 α$ ) bremsstrahlung and photon dissociation cross sections are derived and computed for two different $α - α$ potentials. The available experimental energy dependence is reproduced and a series of other cross sections are predicted. The transition strengths are defined and derived from the cross sections, and compared to schematic rotational model predictions. The computed properties of the $^{12}$ C resonances suggest that the two lowest bands are made, respectively, by the states ${0_{1}^{+}, 2_{1}^{+}, 4_{2}^{+}}$ and ${0_{2}^{+}, 2_{2}^{+}, 4_{1}^{+}}$ . The transitions between the states in the first band are consistent with the rotational pattern corresponding to three alphas in an equal sided triangular structure. For the second band, the transitions are also consistent with a rotational pattern, but with the three alphas in an aligned distribution.
Comments:
To be published in Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1505.01346 [pdf]
PRC(2015)·10 citations
03
[Submitted on 6 May 2015]
Three-body continuum wave functions with a box boundary condition
E. Garrido
In this work we investigate the connection between discretized three-body continuum wave functions, in particular via a box boundary condition, and the wave functions computed with the correct asymptotics. The three-body wave functions are in both cases obtained by means of the adiabatic expansion method. The information concerning all the possible incoming and outgoing channels, which appears naturally when the continuum is not discretized, seems to be lost when the discretization is implemented. In this work we show that both methods are fully equivalent, and the full information contained in the three-body wave function is actually preserved in the discrete spectrum. Therefore, in those cases when the asymptotic behaviour is not known analytically, i.e., when the Coulomb interaction is involved, the discretization technique can be safely used.
Comments:
to be published in Few-body Systems
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1505.01349 [pdf]
Few Body Syst.(2015)·5 citations
04
[Submitted on 6 May 2015]
Energy loss, hadronization and hadronic interactions of heavy flavors in relativistic heavy-ion collisions
Shanshan Cao🇺🇸 · Guang-You Qin🇨🇳 · Steffen A. Bass🇺🇸
We construct a theoretical framework to describe the evolution of heavy flavors produced in relativistic heavy-ion collisions. The in-medium energy loss of heavy quarks is described using our modified Langevin equation that incorporates both quasi-elastic scatterings and the medium-induced gluon radiation. The space-time profiles of the fireball is described by a (2+1)-dimensional hydrodynamics simulation. A hybrid model of fragmentation and coalescence is utilized for heavy quark hadronization, after which the produced heavy mesons together with the soft hadrons produced from the bulk QGP are fed into the hadron cascade UrQMD model to simulate the subsequent hadronic interactions. We find that the medium-induced gluon radiation contributes significantly to heavy quark energy loss at high $p_{T}$ ; heavy-light quark coalescence enhances heavy meson production at intermediate $p_{T}$ ; and scatterings inside the hadron gas further suppress the $D$ meson $R_{AA}$ at large $p_{T}$ and enhance its $v_{2}$ . Our calculations provide good descriptions of heavy meson suppression and elliptic flow observed at both the LHC and RHIC.
Comments:
13 pages, 12 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1505.01413 [pdf]
PRC(2015)·203 citations

Affiliations

first authorsco-authorsvia INSPIRE

A new renormalization procedure of the quasiparticle random phase approximation

Three-body bremsstrahlung and the rotational character of the 12C-spectrum

Three-body continuum wave functions with a box boundary condition

Energy loss, hadronization and hadronic interactions of heavy flavors in relativistic heavy-ion collisions

Affiliations