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Nuclear Theory·nucl-th

Friday·May 28, 2021

8 papers—4 primary·4 cross-listed

All8Primary4Cross-lists4
  1. 05

    [Submitted on 26 May 2021] (cross-list from quant-ph)

    Qudit circuits with SU(d) symmetry: Locality imposes additional conservation laws

    Iman Marvian🇺🇸 · Hanqing Liu🇺🇸 · Austin Hulse🇺🇸

    Local symmetric quantum circuits provide a simple framework to study the dynamics and phases of complex quantum systems with conserved charges. However, some of their basic properties have not yet been understood. Recently, it has been shown that such quantum circuits only generate a restricted subset of symmetric unitary transformations [I. Marvian, Nature Physics, 2022]. In this paper, we consider circuits with 2-local SU(d)-invariant unitaries acting on qudits, i.e., d-dimensional quantum systems. Our results reveal a significant distinction between the cases of d = 2 and d>2. For qubits with SU(2) symmetry, arbitrary global rotationally-invariant unitaries can be generated with 2-local ones, up to relative phases between the subspaces corresponding to inequivalent irreducible representations (irreps) of the symmetry, i.e., sectors with different angular momenta. On the other hand, for d>2, in addition to similar constraints on the relative phases between the irreps, locality also restricts the generated unitaries inside these conserved subspaces. These constraints impose conservation laws that hold for dynamics under 2-local SU(d)-invariant unitaries, but are violated under general SU(d)-invariant unitaries. Based on this result, we show that the distribution of unitaries generated by random 2-local SU(d)-invariant unitaries does not converge to the Haar measure over the group of all SU(d)-invariant unitaries, and in fact, for d>2, is not even a 2-design for the Haar distribution.

    Comments:
    The results are further extended and the preliminary version is now split into multiple papers. 15 pages+19 pages of Appendices, 3 Figures
    Subjects:
    Quantum Physics (quant-ph); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics — Theory (hep-th); Mathematical Physics (math-ph); math.MP (math.MP); Nuclear Theory (nucl-th)
    arXiv:
    2105.12877 [pdf]
    28 citations
  2. 06

    [Submitted on 27 May 2021] (cross-list from hep-ph)

    Case for quarkyoniclike matter from a constituent quark model

    Aaron Park🇰🇷 · Kie Sang Jeong🇺🇸 · Su Houng Lee🇰🇷

    Based on the fact that the constituent quark model reproduces the recent lattice result on baryon-baryon repulsion at short distance and that it includes the quark dynamics with confinement, we analyze to what extent the quarkyonic modes appear in the phase space of baryons as one increases the density before only quark dynamics and hence deconfinement occurs. We find that as one increases the baryon density, the initial quark mode that appears will involve the -quark from a neutron (proton), which will leave the most attractive () diquark intact.

    Comments:
    8 pages, 6 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2105.12948 [pdf]
    PRD(2021)·11 citations
  3. 07

    [Submitted on 24 May 2021] (cross-list from physics.data-an)

    Effect of non-uniform efficiency on higher-order cumulants in heavy-ion collisions

    Fan Si🇨🇳 · Yifei Zhang🇨🇳 · Xiaofeng Luo🇨🇳

    We perform a systematic study on the effect of non-uniform track efficiency correction in higher-order cumulant analysis in heavy-ion collisions. Through analytical derivation, we find that the true values of cumulants can be successfully reproduced by the efficiency correction with an average of the realistic detector efficiency for particles with the same charges within each single phase space. The theoretical conclusions are supported by a toy model simulation by tuning the non-uniformity of the efficiency employed in the track-by-track efficiency correction method. The valid averaged efficiency is found to suppress the statistical uncertainties of the reproduced cumulants dramatically. Thus, usage of the averaged efficiency requires a careful study of phase space dependence. This study is important for carrying out precision measurements of higher-order cumulants in heavy-ion collision experiments at present and in future.

    Comments:
    21 pages and 17 figures
    Subjects:
    Data Analysis, Statistics and Probability (physics.data-an); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2105.13128 [pdf]
    CPC(2021)·1 citation
  4. 08

    [Submitted on 27 May 2021] (cross-list from astro-ph.HE)

    Neutron star asteroseismology and nuclear saturation parameter

    Hajime Sotani

    Adopting various unified equations of state (EOSs), we examine the quasinormal modes of gravitational waves from cold neutron stars. We focus on the fundamental (-), 1st pressure (-), and 1st spacetime (-) modes, and derive the empirical formulae for the frequencies and damping rate of those modes. With the resultant empirical formulae, we find that the value of , which is a specific combination of the nuclear saturation parameters, can be estimated within accuracy, if the -mode frequency from the neutron star whose mass is known would be observed or if the - and -mode frequencies would be simultaneously observed, even though this estimation is applicable only for the low-mass neutron stars. Additionally, we find that the mass and radius of canonical neutron stars can be estimated within a few per cent accuracy via the simultaneous observations of the - and -mode frequencies. We also find that, if the -, -, and -mode frequencies would be simultaneously observed, the mass of canonical neutron stars can be estimated within accuracy, while the radius can be estimated within for the neutron star with or within for the neutron star with constructed with the EOS constrained via the GW170817 event. Furthermore, we find the strong correlation between the maximum -mode frequency and the neutron star radius with the maximum mass, between the minimum -mode frequency and the maximum mass, and between the minimum damping rate of the -mode and the stellar compactness for the neutron star with the maximum mass.

    Comments:
    accepted for publication in PRD. arXiv admin note: text overlap with arXiv:2011.03167
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    2105.13212 [pdf]
    PRD(2021)·34 citations

Affiliations

first authorsco-authorsvia INSPIRE