Nuclear Theory·nucl-th

Monday·March 21, 2016

7 papers—3 primary·4 cross-listed

01
Hadron-Hadron Correlation and Interaction from Heavy-Ion Collisions
Akira Ohnishi🇯🇵 · Kenji Morita🇯🇵 · Kenta Miyahara🇯🇵 · Tetsuo Hyodo🇯🇵
We investigate the $ΛΛ$ and $K^{-} p$ intensity correlations in high-energy heavy-ion collisions. First, we examine the dependence of the $ΛΛ$ correlation on the $ΛΛ$ interaction and the $ΛΛ$ pair purity probability $λ$ . For small $λ$ , the correlation function needs to be suppressed by the $ΛΛ$ interaction in order to explain the recently measured $ΛΛ$ correlation data. By comparison, when we adopt the $λ$ value evaluated from the experimentally measured $Σ^{0} /Λ$ ratio, the correlation function needs to be enhanced by the interaction. We demonstrate that these two cases correspond to the two analyses which gave opposite signs of the $ΛΛ$ scattering length. Next, we discuss the $K^{-} p$ correlation function. By using the local $K ˉ N$ potential which reproduces the kaonic hydrogen data by SIDDHARTA, we obtain the $K^{-} p$ correlation function. We find that the $K^{-} p$ correlation can provide a complementary information with the $K^{-} p$ elastic scattering amplitude.
nucl-thhep-phnucl-exNPA(2016)·74 citations
02
Highly-anisotropic hydrodynamics for central collisions
Radoslaw Ryblewski🇵🇱
The framework of leading-order anisotropic hydrodynamics is supplemented with realistic equation of state and self-consistent freeze-out prescription. The model is applied to central proton-nucleus collisions. The results are compared to those obtained within standard Israel-Stewart second-order viscous hydrodynamics. It is shown that the resulting hadron spectra are highly-sensitive to the hydrodynamic approach that has been used.
nucl-thhep-phActa Phys.Polon.Supp.(2016)·0 citations
03
Formation of deuterons by coalescence: Consequences on the deuteron number fluctuations
Zuzana Feckova🇸🇰 · Jan Steinheimer🇩🇪 · Boris Tomasik🇸🇰 · Marcus Bleicher🇩🇪
Two scenarios for cluster production have since long been discussed in the literature: i) direct emission of the clusters from a (grand canonical) thermal source or ii) subsequent formation of the clusters by coalescence of single nucleons. While both approaches have been successfully applied in the past it has not yet been clarified which of the two mechanisms dominates the cluster production. We propose to use recently developed event-by-event techniques to study particle multiplicity fluctuations on nuclear clusters and employ this analysis to the deuteron number fluctuations to disentangle the two production mechanisms. We argue that for a grand canonical cluster formation, the cluster fluctuations will follow Poisson distribution, while for the coalescence scenario, the fluctuations will strongly deviate from the Poisson expectation. We estimate the effect to be 10% for the variance and up to a factor of 5 for the kurtosis of the deuteron number multiplicity distribution. Our prediction can be tested in the beam energy scan program at RHIC as well as experiments at the FAIR and NICA facilities.
nucl-thnucl-exPRC(2016)·31 citations
04
General considerations on the nature of $Z_{b} (10610)$ and $Z_{b} (10650)$ from their pole positions
Xian-Wei Kang🇪🇸 · Zhi-Hui Guo🇩🇪 · J. A. Oller🇪🇸
The nature of the bottomonium-like states $Z_{b} (10610)$ and $Z_{b} (10650)$ is studied by calculating the $B^{(*)} B^{*}$ compositeness ( $X$ ) in those resonances. We first consider uncoupled isovector $S$ -wave scattering of $B^{(*)} B^{*}$ within the framework of effective-range expansion (ERE). Expressions for the scattering length ( $a$ ) and effective range ( $r$ ) are derived exclusively in terms of the masses and widths of the two $Z_{b}$ states. We then develop compositeness within ERE for the resonance case and deduce the expression $X = 1/ 2 r / a - 1$ , which is then applied to the systems of interest. Finally, the actual compositeness parameters are calculated in terms of resonance pole positions and their experimental branching ratios into $B^{(*)} B^{*}$ by using the method of Ref.[1]. We find the values $X = 0.66 \pm 0.11$ and $0.51 \pm 0.10$ for the $Z_{b} (10610)$ and $Z_{b} (10650)$ , respectively. We also compare the ERE with Breit-Wigner and Flatté parameterizations to discuss the applicability of the last two ones for near-threshold resonances with explicit examples.
↳ hep-phhep-exhep-latnucl-thPRD(2016)·73 citations
05
Enhanced violation of the Lorentz invariance and Einstein's equivalence principle in nuclei and atoms
V.V. Flambaum🇦🇺
Local Lorentz Invariance violating (LLIV) and Einstein equivalence principle violating (EEPV) effects in atomic experiments are discussed. The EEPV effects are strongly enhanced in the narrow 7.8 eV transition in 229Th nucleus. Nuclear LLIV momentum tensors describing anisotropy in the maximal attainable speed for massive particles (analog of Michelson-Morley experiment for light) are expressed in terms of the experimental values of nuclear quadrupole moments. Calculations for nuclei of experimental interest 133Cs, 85Rb, 87Rb, 201Hg, 131Xe and 21Ne have been performed. The results for 21Ne are used to improve the limits on the proton LLIV constants by 4 orders of magnitude.
↳ physics.atom-phhep-phnucl-thPRL(2016)·55 citations
06
Strange quark matter and quark stars with the Dyson-Schwinger quark model
H. Chen🇨🇳 · J.-B Wei🇨🇳 · H.-J. Schulze🇮🇹
We calculate the equation of state of strange quark matter and the interior structure of strange quark stars in a Dyson-Schwinger quark model within rainbow or Ball-Chiu vertex approximation. We emphasize constraints on the parameter space of the model due to stability conditions of ordinary nuclear matter. Respecting these constraints, we find that the maximum mass of strange quark stars is about 1.9 solar masses, and typical radii are 9 --11 km. We obtain an energy release as large as $3.6 \times 1 0^{53} erg$ from conversion of neutron stars into strange quark stars.
↳ astro-ph.SRhep-phnucl-thEPJA(2016)·24 citations
07
Matching universal behavior with potential models
R. Álvarez-Rodríguez · A. Deltuva. M. Gattobigio · A. Kievsky
Two-, three-, and four-boson systems are studied close to the unitary limit using potential models constructed to reproduce the minimal information given by the two-body scattering length $a$ and the two-body binding energy or virtual state energy $E_{2}$ . The particular path used to reach the unitary limit is given by varying the potential strength. In this way the energy spectrum in the three- and four-boson systems is computed. The lowest energy states show finite-range effects absorbed in the construction of level functions that can be used to study real systems. Higher energy levels are free from finite-range effects, therefore the corresponding level functions tend to the zero-range universal function. Using this property a zero-range equation for the four-boson system is proposed and the four-boson universal function is computed.
↳ cond-mat.quant-gasnucl-thPRA(2016)·21 citations

Affiliations

first authorsco-authorsvia INSPIRE

Hadron-Hadron Correlation and Interaction from Heavy-Ion Collisions

Highly-anisotropic hydrodynamics for central collisions

Formation of deuterons by coalescence: Consequences on the deuteron number fluctuations

General considerations on the nature of Zb​(10610) and Zb​(10650) from their pole positions

Enhanced violation of the Lorentz invariance and Einstein's equivalence principle in nuclei and atoms

Strange quark matter and quark stars with the Dyson-Schwinger quark model

Matching universal behavior with potential models

Affiliations

General considerations on the nature of $Z_{b} (10610)$ and $Z_{b} (10650)$ from their pole positions