scholarly journals Manifestation of hidden symmetries in baryonic matter: From finite nuclei to neutron stars

2021 ◽  
Vol 36 (13) ◽  
pp. 2130012
Author(s):  
Mannque Rho ◽  
Yong-Liang Ma
Keyword(s):  
Compact Stars ◽  
Light Nuclei ◽  
Baryonic Matter ◽  
Topology Change ◽  
Hidden Symmetries ◽  
Nuclear Matter Density ◽  
The Core ◽  
Long Time ◽  
Finite Nuclei ◽  
Gamow Teller

When hadron-quark continuity is formulated in terms of a topology change at a density higher than twice the nuclear matter density [Formula: see text], the core of massive compact stars can be described in terms of quasiparticles of fractional baryon charges, behaving neither like pure baryons nor like deconfined quarks. Hidden symmetries, both local gauge and pseudo-conformal (or broken scale), emerge and give rise both to the long-standing “effective [Formula: see text]” in nuclear Gamow–Teller (GT) transitions at [Formula: see text] and to the pseudo-conformal sound velocity [Formula: see text] at [Formula: see text]. It is suggested that what has been referred to, since a long time, as “quenched [Formula: see text]” in light nuclei reflects what leads to the dilaton-limit [Formula: see text] at near the (putative) infrared fixed point of scale invariance. These properties are confronted with the recent observations in GT transitions and in astrophysical observations.

scholarly journals FLAVOR SYMMETRY AND TOPOLOGY CHANGE IN NUCLEAR SYMMETRY ENERGY FOR COMPACT STARS

2013 ◽  
Vol 22 (03) ◽  
pp. 1330005 ◽  
Author(s):  
HYUN KYU LEE ◽  
MANNQUE RHO
Keyword(s):  
Symmetry Energy ◽  
Compact Star ◽  
Conformal Symmetry ◽  
Compact Stars ◽  
Stellar Structure ◽  
Mass Star ◽  
Nuclear Symmetry Energy ◽  
Baryonic Matter ◽  
Topology Change ◽  
Kaon Condensation

The nuclear symmetry energy figures crucially in the structure of asymmetric nuclei and, more importantly, in the equation of state (EoS) of compact stars. At present it is almost totally unknown, both experimentally and theoretically, in the density regime appropriate for the interior of neutron stars. Basing on a strong-coupled structure of dense baryonic matter encoded in the skyrmion crystal approach with a topology change and resorting to the notion of generalized hidden local symmetry in hadronic interactions, we address a variety of hitherto unexplored issues of nuclear interactions associated with the symmetry energy, i.e., kaon condensation and hyperons, possible topology change in dense matter, nuclear tensor forces, conformal symmetry, chiral symmetry, etc., in the EoS of dense compact-star matter. One of the surprising results coming from HLS structure that is distinct from what is given by standard phenomenological approaches is that at high density, baryonic matter is driven by renormalization group flow to the "dilaton-limit fixed point" constrained by "mended symmetries". We further propose how to formulate kaon condensation and hyperons in compact-star matter in a framework anchored on a single effective Lagrangian by treating hyperons as the Callan–Klebanov kaon-skyrmion bound states simulated on crystal lattice. This formulation suggests that hyperons can figure in the stellar matter — if at all — when or after kaons condense, in contrast to the standard phenomenological approaches where the hyperons appear as the first strangeness degree of freedom in matter, thereby suppressing or delaying kaon condensation. In our simplified description of the stellar structure in terms of symmetry energies, which is compatible with that of the 1.97 solar mass star, kaon condensation plays a role of "doorway state" to strange quark matter.

scholarly journals ${\bar K}$-NUCLEAR DEEPLY BOUND STATES?

2007 ◽  
Vol 16 (03) ◽  
pp. 891-903
Author(s):  
AVRAHAM GAL
Keyword(s):  
Bound States ◽  
Decay Channel ◽  
Matter Density ◽  
Binding Energies ◽  
Light Nuclei ◽  
Nuclear Level ◽  
Core Nucleus ◽  
Nuclear Matter Density ◽  
The Core ◽  
Energy Dependent

Following the prediction by Akaishi and Yamazaki of relatively narrow [Formula: see text]-nuclear states, deeply bound by over 100 MeV where the main decay channel [Formula: see text] is closed, several experimental signals in stopped K- reactions on light nuclei have been interpreted recently as due to such states. In this talk I review (i) the evidence from K--atom data for a deep[Formula: see text]-nucleus potential, as attractive as [Formula: see text] at nuclear matter density, that could support such states; and (ii) the theoretical arguments for a shallow potential, [Formula: see text]. I then review a recent work by Mareš, Friedman and Gal in which [Formula: see text]-nuclear bound states are generated dynamically across the periodic table, using a RMF Lagrangian that couples the [Formula: see text] to the scalar and vector meson fields mediating the nuclear interactions. The reduced phase space available for [Formula: see text] absorption from these bound states is taken into account by adding a density- and energy-dependent imaginary term, underlying the corresponding [Formula: see text]-nuclear level widths, with a strength constrained by K--atom fits. Substantial polarization of the core nucleus is found for light nuclei, with central nuclear densities enhanced by almost a factor of two. The binding energies and widths calculated in this dynamical model differ appreciably from those calculated for a static nucleus. These calculations provide a lower limit of [Formula: see text] on the width of nuclear bound states for [Formula: see text] binding energy in the range [Formula: see text].

scholarly journals Topology change, emergent symmetries and compact star matter

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Yong-Liang Ma ◽  
Mannque Rho
Keyword(s):  
Nuclear Matter ◽  
Compact Star ◽  
Momentum Tensor ◽  
Effective Field ◽  
Compact Stars ◽  
Strongly Correlated ◽  
Topology Change ◽  
Dense Nuclear Matter ◽  
Skyrmion Matter ◽  
Energy Constants

AbstractTopology effects have being extensively studied and confirmed in strongly correlated condensed matter physics. In the limit of large number of colors, baryons can be regarded as topological objects—skyrmions—and the baryonic matter can be regarded as a skyrmion matter. We review in this paper the generalized effective field theory for dense compact-star matter constructed with the robust inputs obtained from the skyrmion approach to dense nuclear matter, relying on possible “emergent” scale and local flavor symmetries at high density. All nuclear matter properties from the saturation density n0 up to several times n0 can be fairly well described. A uniquely novel—and unorthdox—feature of this theory is the precocious appearance of the pseudo-conformal sound velocity $v^{2}_{s}/c^{2} \approx 1/3$ v s 2 / c 2 ≈ 1 / 3 , with the non-vanishing trace of the energy momentum tensor of the system. The topology change encoded in the density scaling of low energy constants is interpreted as the quark-hadron continuity in the sense of Cheshire Cat Principle (CCP) at density $\gtrsim 2n_{0}$ ≳ 2 n 0 in accessing massive compact stars. We confront the approach with the data from GW170817 and GW190425.

Leaving Agent-Relative Value Behind

Utilitas ◽  
2020 ◽  
pp. 1-15
Author(s):  
Christa M. Johnson
Keyword(s):  
Left Behind ◽  
The Core ◽  
Relative Value ◽  
Long Time ◽  
Commonsense Morality

Abstract Commonsense morality seems to feature both agent-neutral and agent-relative elements. For a long time, the core debate between consequentialists and deontologists was which of these features should take centerstage. With the introduction of the consequentializing project and agent-relative value, however, agent-neutrality has been left behind. While I likewise favor an agent-relative view, agent-neutral views capture important features of commonsense morality. This article investigates whether an agent-relative view can maintain what is attractive about typical agent-neutral views. In particular, I argue that the agent-relative reasons-wielding deontologist is ultimately able to capture those features ordinarily associated with agent-neutral views, while the agent-relative value wielding consequentialist is left with a dilemma. The consequentializer either succumbs to the concerns of her agent-neutral opponents or else abandons the distinctive and attractive features of her view. Either way, I conclude that agent-relative value is best left behind.

Thermal Performance Evaluation of Cork Phenolic for Nozzle External Thermal Protection System Using 250 kW Plasma Jet Facility

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
L. Aravindakshan Pillai ◽  
N. Sreenivas ◽  
K. Krishnaraj ◽  
Vinay Unnikrishnan ◽  
M. Ajith
Keyword(s):  
Thermal Performance ◽  
Thermal Protection ◽  
Plasma Jet ◽  
Thermal Protection System ◽  
Protection System ◽  
Convective Heating ◽  
Launch Vehicles ◽  
Time Of Application ◽  
The Core ◽  
Long Time

In one of the launch vehicles of ISRO, there are two solid strap-ons attached to the core liquid engine. During the ascent phase, the external nozzle divergent of the strap-ons experiences heating due to radiation from the strap-ons as well as convective heating from the impingement of plumes from the core engine. Hence, the nozzle divergent of the strap-on beyond compliance ring is thermally protected by a coating of PC10 insulation applied over carbon/epoxy structural backup. Though the system worked satisfactorily, application of PC10 had increased the inert weight of each nozzle by 165 kg and took long time for realization. To reduce the inert weight as well as the time of application, precast phenolic based cork sheets (CkP) having lower density than PC10 were selected, as a replacement to PC10. As part of evaluating the thermal performance of the CkP material, specimen level tests with different configurations were carried out in 250 kW plasma jet facility of Vikram Sarabhai Space Centre (VSSC) wherein both the heat flux and the shear stress as expected in flight were simulated simultaneously. At the end of the test program, CkP was found to be superior to PC10 for external thermal protection system (TPS). This paper highlights details of the qualification tests carried out for clearing the cork phenolic system for use in the future launches.

Quartetting in Fermionic Matter and Alpha-Particle Condensation in Nuclear Systems

2006 ◽  
Vol 21 (31n33) ◽  
pp. 2513-2546 ◽  
Author(s):  
G. Röpke ◽  
P. Schuck
Keyword(s):  
Nuclear Matter ◽  
Cluster Formation ◽  
Mean Field ◽  
Field Approximation ◽  
Mean Field Approximation ◽  
Density Region ◽  
Nuclear Matter Density ◽  
Nuclear Systems ◽  
The Mean ◽  
Finite Nuclei

Quantum condensates in nuclear matter are treated beyond the mean-field approximation, with the inclusion of cluster formation. The occurrence of a separate binding pole in the four-particle propagator in nuclear matter is investigated with respect to the formation of a condensate of α-like particles (quartetting), which is dependent on temperature and density. Due to Pauli blocking, the formation of an α-like condensate is limited to the low-density region. Consequences for finite nuclei are considered. In particular, excitations of self-conjugate 2n-Z–2n-N nuclei near the n-α-breakup threshold are candidates for quartetting. We review some results and discuss their consequences. Exploratory calculations are performed for the density dependence of the α condensate fraction at zero temperature to address the suppression of the four-particle condensate below nuclear-matter density.

scholarly journals The Excess Secular Change in the Obliquity of the Ecliptic and Its Relation to the Internal Motion of the Earth

1972 ◽  
Vol 48 ◽  
pp. 192-195 ◽  
Author(s):  
Chuichi Kakuta ◽  
Shinko Aoki
Keyword(s):  
Time Variation ◽  
Rotational Speed ◽  
Internal Motion ◽  
Secular Change ◽  
Electrically Conducting ◽  
The Core ◽  
The Earth ◽  
Fluid Core ◽  
Electrical Conductivities ◽  
Long Time

The previous result (Aoki, 1969) on the explanation of the excess secular change in the obliquity of the ecliptic frictional couplings in the rigid constituents, the mantle and the core, is extended by using a model of an elastic and electrically conducting mantle and a hydromagnetic core. The secular change of the obliquity of the ecliptic referred to the mantle is found to be 1/3.2 times of the observed value, if the electrical conductivities of the fluid core and the mantle are assumed to be 3·10−6 emu and 3·10−9 emu respectively. A large secular deceleration of the Earth's rotational speed obtained in the previous result is proved to be strongly reduced because of weak excitation of the perturbing potential for a long time variation.

scholarly journals Population, and its social and religious composition in Ivanovo and Yaroslavl regions on the eve of the Axis aggression against the USSR (according to the censuses of the USSR in 1937 and 1939)

2021 ◽  
Vol 27 (1) ◽  
pp. 74-78
Author(s):  
Natalya S. Maiorova
Keyword(s):  
World War Ii ◽  
Rural Areas ◽  
Urban Population ◽  
Daily Life ◽  
World War ◽  
Religious Policy ◽  
The Core ◽  
Long Time ◽  
High Level ◽  
Anxiety And Fear

The article is devoted to the analysis of the results of population censuses conducted in the USSR in 1937 and 1939, in relation to Ivanovo and Yaroslavl regions. The research is based on census materials that had been classified for a long time and published only in the 1990s. Of all the various aspects of the censuses, the author's attention was focused on only three – population, its social structure, and religious composition. Based on the results of the censuses, conclusions are drawn about the prevalence of women in the region, both in rural areas and in cities. It was women who, in the conditions of World War II, became the strong rear, on whose shoulders the front was supported by food, uniforms, and weapons. The urban population was greater in Ivanovo Region, which was explained by its characteristic high rates of industrialisation. The 1937 census recorded a fairly high level of religiosity, despite the largely anti-religious policy that had been carried out for almost 20 years. The war led to an increase in religiosity, probably because often only faith could become the core around which daily life was built, full of deprivation, anxiety and fear for loved ones.

scholarly journals Thorium application in the medium-sized sodium-cooled fast reactor

2019 ◽  
Vol 137 ◽  
pp. 01030
Author(s):  
Eeshu Raaj Saasthaa Arumuga Kumar ◽  
Piotr Darnowski ◽  
Mihir Kiritbhai Pancholi ◽  
Aleksandra Dzido
Keyword(s):  
Fast Reactor ◽  
Waste Incineration ◽  
Computer Code ◽  
Fuel Cycles ◽  
Mixed Oxide Fuel ◽  
The Core ◽  
Long Time ◽  
The Impact ◽  
Thorium 232 ◽  
Full Core

The report presents an analysis of the medium-sized Sodium-Cooled Fast Reactor (SFR) core with Thorium-based Mixed-Oxide fuel. The introduction of Transuranics (TRU) to the fuel was to allow long-lived nuclear waste incineration. The studied core is based on the modified Advanced Burner Reactor (ABR) 1000MWth core design, which was analysed in the OECD/NEA “Benchmark for Neutronic Analysis of Sodium-Cooled Fast Reactor Cores with Various Fuel Types and Core Sizes”. The full-core simulations with SERPENT 2.1.31 Monte Carlo computer code and ENDF library were performed, including static criticality and fuel burnup calculations for five fuel cycles. The core inventories at the Beginning of Cycle (BOC) and End of Cycle (EOC) were studied, and the impact of thorium fuel was assessed. The proposed core design is a burner reactor which uses thorium fuel. The excess core reactivity stays positive for long time despite large net consumption of transuranic elements as new fissile Uranium 233 is constantly breed from Thorium 232. Breeding of uranium allows longer fuel cycles.

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