arXiv subjects

Mannque Rho

Publications and source records attributed to Mannque Rho.

At least 19 recordsLinked to original sources

arXiv2025

A Bottom-Up EFT Approach To Superdense Baryonic Matter

How to arrive at the densest matter in massive compact stars starting from Walecka's linear $\omega$-$\sigma$ mean-field model is described in a series of arguments anchored on hidden local symmetry, hidden scale symmetry and emergent parity-doublet symmetry. I follow the bottom-up approach from chiral symmetry with pions, coupled to hidden local and scale symmetry degrees of freedom. Exploiting the renormalization-group treatment \`a la Shankar and Polchinski of the fermionic interactions on the Fermi sphere, leading to Landau-Migdal Fermi-liquid, one obtains a sort of generalized ``Density Functional" that allows via a topology change hadrons transform to quarks without phase changes at the center of massive stars. The highly dense matter is ``pseudo-conformal" with the sound velocity $v_{pcs}^2/c^2\approx 1/3$ but the trace of the energy-momentum tensor is not equal to zero, hence the matter is non-conformal.

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arXiv2025

From Nuclear Matter with Quenched $g_A$ to Compact-Star Matter with a Signal for Emergent Hidden Scale Symmetry

An ``unorthodox" idea is developed that the long-standing mystery in nuclear physics of the effective axial-current coupling constant in nuclei, $g_A^{\rm eff}\approx 1$, could be interpreted in terms of an emerging hidden scale symmetry in dense compact-star matter. Arguments are presented using an effective field theory anchored on a renormalization-group approach to interacting baryons on the Fermi surface coupled with hidden symmetric heavy mesonic degrees of freedom that enables one to go beyond Weinberg's nuclear effective field theory involving nucleon and pion fields only, referred hereon to as $\chi$EFT$_\pi$. Both hidden local and scale symmetries, the former involving the vector mesons $\rho$ and $\omega$ and the latter the hidden scalar meson, a dilaton $\hat{\sigma}$ (i.e., $f_0(500)$), play the crucial role. Going beyond the density regime applicable to normal nuclear matter $n_0$, the notion of ``hadron-quark continuity HQC)" is brought in via the skyrmion structure of the nucleon argued to be valid in QCD at large $N_c$ limit and the large $N^\prime$ limit of the Grassmannian model $G/H= [O(N^\prime)/O(N^\prime-p) \times O(p)]$ where $N^\prime=4$ and $p=2$ for hidden local symmetry and the IR fixed point in QCD for $N_f \leq 3$ involving ``genuine/QCD-conformal dilaton" for hidden scale symmetry. The connection between the quenched $g_A$ and the sound speed $v^2_{s}/c^2\approx 1/3$ inside dense compact stars could be interpreted as a signal for emergent ``pseudo-conformal" symmetry.

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arXiv2024

Probing for an IR-fixed Point in QCD by Superallowed Gamow-Teller Transitions in Doubly Magic Nuclei

This brief note is to point out that the recent measurements at GSI and RIKEN of the superallowed Gamow-Teller transition in the doubly magic closed-shell nucleus $^{100}$Sn could give an indication for a possibly important {\it fundamental} quenching, thus-far unrecognized, of $g_A$, unambiguously distinct from nuclear correlation effects in the framework of nuclear effective field theory. The result, either confirmed or ruled out both experimentally and theory, can have strong impacts on nuclear physics vis-\`a-vis with nuclear effective field theory as well as on particle physics relevant for going beyond the Standard Model.

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arXiv2024

The Smile of Cheshire Cat At High Density

Baryons in finite nuclei, nuclear matter and dense compact-star matter are described in terms of Cheshire Cat for QCD. A potential conceptual link, admittedly short in mathematical rigor, between their manifestations is made by what's called Cheshire Cat Principle. Put in terms taken ``dual" to QCD variables, going to very high density exposes quantum Hall droplets -- or pancakes -- at which the dilaton-limit fixed point with $g_A\to 1$, $f_\pi\to f_\chi$ -- where $f_\pi$ and $f_\chi$ are respectively the pion and dilaton decay constants -- and the baryon parity-doubling are reached. This scenario suggests a thus-far totally unexplored structure of dual baryonic matter at high density which does neither require nor rule out (rapid) first-order phase transitions from hadrons to quarks in the core of compact stars on the verge of gravitational collapse.

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arXiv2024

The Quenched ${g_A}$ Puzzle in Nuclei & Nuclear Matter and "Pseudo-Conformality" in QCD

The long-standing puzzle of the quenched $g_A$ in nuclei is shown to have an extremely simple resolution in a renormalization-group (RG) treatment of a hidden local symmetric (HLS) and scale-symmetric (HSS) chiral Lagrangian. It is shown that the Landau-Migdal fixed-point approximation in nuclear matter (or $V_{lowk}$ in finite nuclei) in RG approach to strong correlations of fermionic hadrons on the Fermi surface {\it exactly} reproduces the superallowed Gamow-Teller transitions in the ``Extreme Single-Particle (shell-)Model (ESPM)" in doubly-magic closed shell nuclei. One arrives at the quenching factor $q\approx 0.78$ giving the quenched $g_A^{\rm eff} \approx 1$. This resolution exposes scale-chiral symmetry, hidden in QCD in the vacuum, emerging in nuclear matter from low density to high compact-star density. It has important implications on ``first principles" approaches to nuclear physics, such as the role of multi-body exchange currents in weak axial-current matrix elements in nuclei and in neutrinoless double $\beta$ decays for going Beyond the Standard Model. This resolution could put in serious doubt the most recent improved measurement of the superallowed Gamow-Teller transition in the doubly-magic closed shell nucleus $^{100}$Sn which if confirmed would require a ``{\it fundamental quenching}" $q_{ssb}\sim 1/2$.

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arXiv2024

$V_{lowk}$ Renormalization Group Flow, Vector Manifestation and Sound Velocity in Massive Compact Stars

The $V_{lowk}$-renormalization group approach on the surface of Fermi liquid for nuclear matter to which Tom Kuo made a pioneering contribution at Stony Brook is found to inject the pivotal input in the formulation of the generalized nuclear effective field theory with acronym ``G$n$EFT" applicable to superdense compact-star physics. A topology change in terms of skyrmions and half-skyrmions is shown to play the role of the ``putative" hadron-quark continuity (HQC)" conjectured in QCD. Crucially involved are hidden local symmetry (``HLS") and hidden scale symmetry (``HSS") with the vacuum sliding with density in nuclear medium, with the nuclear tensor force emerging as a Landau Fermi-liquid fixed-point quantity. A possibly novel paradigm, a ``Cheshire Catism," in nuclear correlations is suggested.

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arXiv2023

Corrections to Landau Fermi-liquid fixed-point approximation in nonlinear bosonized theory: Application to $g_A^L$ in nuclei

We calculated in nonlinear bosonized theory $1/\bar{N}$ corrections to the Landau Fermi-liquid fixed-point (FLFP) axial-vector coupling constant in nuclear matter $g_A^L\approx 1$ to which the Landau parameter $F_1^\omega$ predominantly contributes. We obtain the correction to $F_1^\omega$ to calculate the correction $\delta g_A^L$ to the axial-vector coupling constant $g_A^L$ at the nuclear saturation density. It comes out to be extremely small, $\delta g_A^L\sim O(10^{-4})$. We discuss how the "dilaton-limit fixed-point (DLFP)" result $g_A=1$ can be preserved from finite nuclei to high densities relevant to massive neutron stars and its possible impact on $0\nu\beta\beta$ decay processes involved in going beyond the Standard Model.

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arXiv2023

Dense Baryonic Matter Predicted in "Pseudo-Conformal Model"

The World-Class University/Hanyang Project launched in Korea in 2007 led to what's now called ``pseudo-conformal model" that addresses dense compact-star matter and is confronted in this short note with the presently available astrophysical observables, with focus on those from gravity waves. The predictions made nearly free of parameters by the model involving ``topology change" remain more or less intact ``un-torpedoed" by the data.

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arXiv2023

Anomaly-Induced Quenching of ${g_A}$ in Nuclear Matter and Impact on Search for Neutrinoless $\beta\beta$ Decay

How to disentangle the possible {\it genuine} quenching of $g_A$ caused by scale anomaly of QCD parameterized by the scale-symmetry-breaking quenching factor $q_{ssb}$ from nuclear correlation effects is described. This is done by matching the Fermi-liquid fixed point (FLFP) theory to the ``Extreme Single Particle (shell) Model" (acronym ESPM) in superallowed Gamow-Teller transitions in heavy doubly-magic shell nuclei. The recently experimentally observed indication for $(1-q_{ssb})\neq 0$ -- that one might identify as ``fundamental quenching ({\it FQ})" -- in certain experiments seems to be alarmingly significant. I present arguments how symmetries hidden in the matter-free vacuum can emerge and suppress such {\it FQ} in strong nuclear correlations. How to confirm or refute this observation is discussed in terms of the superallowed Gamow-Teller transition in the doubly-magic nucleus $^{100}$Sn and in the spectral shape in the multifold forbidden $\beta$ decay of $^{115}$In.

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arXiv2022

How and How Much is ${g_A}$ {\it Fundamentally} Quenched in Nuclei?

The superallowed Gamow-Teller transition in the doubly-magic-shell nucleus $^{100}$Sn and the high resolution spectral shape analysis in the fourth-forbidden nonunique transition in $^{115}$In indicate as much as $\sim 40\%$ {\it fundamental} quenching in the axial-current coupling constant $g_A$ in nuclei. This can be attributed to an effect of the trace anomaly in QCD "emerging" in nuclear medium. If confirmed, this would signal a major revamping to do in nuclear interactions consistent with chiral-scale symmetry in nuclear medium and a big impact on $0\nu$ and $\nu\nu$ double $\beta$ decays for BSM. I present an argument that such a big anomaly-induced quenching is incompatible with how hidden scale symmetry manifests in nuclear medium, A possible means to resolve this issue is discussed in terms of hidden scale symmetry permeating in baryonic matter from normal nuclear matter to massive compact-star matter.

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arXiv2022

Probing Fractional Quantum Hall Sheets in Dense Baryonic Matter

Unlike the octet baryons for $N_f=3$, there is no skyrmion coming from the $\eta^\prime$ meson. It is instead described as a fractional quantum Hall droplet, a pancake or a pita involving a singular $\eta^\prime$ ring in which Chern-Simons fields live. By incorporating hidden local symmetry and hidden scale symmetry in nuclear dynamics, I describe how to access baryon-charged quantum Hall droplets in dense nuclear matter in terms of the nuclear scale-chiral effective field theory approach ``G$n$EFT" with the $U_A(1)$ anomaly taken into account. I discuss how the single-flavor baryon that I will call ${\cal B}^s$ could be exposed in superdense baryonic matter, figuring, perhaps, in ``quark stars" associated with the baryon-quark continuity involving CFL or phase transitions.

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arXiv2022

"Pseudo-Conformal" Sound Speed in the Core of Compact Stars

We present the argument that "pseudo-conformal" symmetry permeates from low density near nuclear matter to high density in the core of massive neutron stars. As a support of this argument, we describe how the quenched $g_A\approx 1$ in nuclei and the sound speed $v_s^2/c^2\approx 1/3$ in compact stars are controlled by emerging scale invariance in nuclear interactions. In our description, quasi-baryons could "masquerade" de-confined quarks in the interior of compact stars.

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arXiv2022

What "quenches" ${g_A}$ in nuclei ?

The answer is found in the way the hidden scale symmetry involving a dilaton emerges in strong nuclear correlations in nuclear matter. It is suggested that the same mechanism is at the origin at higher densities of the sound speed converging in the core of massive compact stars to what could be called ``pseudo-conformal sound speed" $v_s^2/c^2\approx 1/3$. A precision measurement of the superallowed Gamow-Teller transitions in the doubly magic nucleus $^{100}$Sn is suggested to confirm or falsify this prediction. It could also lead to the possible determination of genuine ``fundamental renormalization" of $g_A$ in nuclear medium.

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arXiv2022

Mapping topology of skyrmions and fractional quantum Hall droplets to nuclear EFT for ultra-dense baryonic matter

We describe the mapping at high density of topological structure of baryonic matter to a nuclear effective field theory that implements hidden symmetries emergent from strong nuclear correlations. The theory so constructed is found to be consistent with no conflicts with the presently available observations in both normal nuclear matter and compact-star matter. The hidden symmetries involved are "local flavor symmetry" of the vector mesons identified to be (Seiberg-)dual to the gluons of QCD and hidden "quantum scale symmetry" with an IR fixed point with a "genuine dilaton (GD)" characterized by non-vanishing pion and dilaton decay constants. Both the skyrmion topology for $N_f \geq 2$ baryons and the fractional quantum Hall (FQH) droplet topology for $N_f=1$ baryons are unified in the "homogeneous/hidden" Wess-Zumino term in the hidden local symmetry (HLS) Lagrangian. The possible indispensable role of the FQH droplets in going beyond the density regime of compact stars approaching scale-chiral restoration is explored by moving toward the limit where both the dilaton and the pion go massless.

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arXiv2021

Skyrmions and Fractional Quantum Hall Droplets Unified by Hidden Symmetries in Dense Matter

A chain of connections in compressed baryonic matter, up-to-date glaringly missing in nuclear effective field theory, between intrinsic or emergent symmetries of QCD, mesons-gluons dualities, vector meson dominance and Chern-Simons fields has recently been revealed, presaging a possible new paradigm in nuclear theory. It indicates a ubiquitous role, thus far unexplored, of hidden symmetries -- flavor-local and scale -- permeating from dilute baryonic systems to normal nuclear matter and then to compact-star matter. Here I give a brief account of the possibly "indispensable" relevance of the $η^\prime$ singular ring, a.k.a. fractional quantum Hall (FQH) droplet, to the properties of the lowest-lying vector mesons $ω$ and $ρ$, relevant to dilepton production processes, argued to be Seiberg-dual to the gluons near the chiral restoration.

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arXiv2021

Multifarious roles of hidden chiral-scale symmetry:"Quenching" ${g_A}$ in nuclei

I discuss how the axial current coupling constant $g_A$ renormalized in scale symmetric chiral EFT defined at a chiral matching scale impacts on the axial current matrix elements on beta decays in nuclei with and without neutrinos. The "quenched" $g_A$ observed in nuclear superallowed Gamow-Teller transitions, a long-standing puzzle in nuclear physics, is shown to encode the emergence of chiral-scale symmetry hidden in QCD in the vacuum. This enables one to explore how trace-anomaly-induced scale symmetry breaking enters in the renormalized $g_A$ in nuclei applicable to certain non-unique forbidden processes involved in neutrinoless double beta decays. A parallel is made between the roles of chiral-scale symmetry in quenching $g_A$ in highly dense medium and in hadron-quark continuity in the EoS of dense matter in massive compact stars. A systematic chiral-scale EFT, presently lacking in nuclear theory and potentially crucial for the future progress, is suggested as a challenge in the field.

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arXiv2021

Dichotomy of Baryons as Quantum Hall Droplets and Skyrmions In Compact-Star Matter

We review the recent exploration of a possible "domain-wall structure" of compressed baryonic matter in massive compact stars in terms of fractional quantum Hall droplets and skyrmions for baryons in medium. The theoretical framework is anchored on an effective nuclear effective field theory that incorporates two hidden symmetries, flavor local symmetry and scale symmetry conjectured to be dual to the gluons and quarks of QCD. It hints at a basically different, hitherto undiscovered structure of nuclear matter at low as well as high densities. Hidden "genuine dilaton (GD)" symmetry and hidden local symmetry (HLS) gauge-equivalent at low density to nonlinear sigma model capturing chiral symmetry, put together in nuclear effective field theory, are seen to play an increasingly important role in providing hadron-quark duality in baryonic matter. This strongly motivates incorporating both symmetries in formulating "first-principles" approaches to nuclear dynamics encompassing from the nuclear matter density to the highest density stable in the Universe.

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arXiv2021

Topology change, emergent symmetries and compact star matter

Topology effects have being extensively studied and confirmed in strongly correlated condensed matter physics. In the large color number limit of QCD, 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 to possible ``emergent" scale and local flavor symmetries at high density. All nuclear matter properties from the saturation density $n_0$ up to several times $n_0$ can be fairly well described. A uniquely novel -- and unorthdox -- feature of this theory is the precocious appearance of the pseudo-conformal sound velocity $v^2_{s}/c^2 \approx 1/3$, 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 $\gsim 2n_0$ in accessing massive compact stars. We confront the approach with the data from GW170817 and GW190425.

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