Nuclear Theory·nucl-th

Thursday·November 12, 2020

10 papers—3 primary·7 cross-listed

01
[Submitted on 11 Nov 2020]
Strangeness $S = - 3$ and $- 4$ baryon-baryon interactions in relativistic chiral effective field theory
Zhi-Wei Liu🇨🇳 · Jing Song🇨🇳 · Kai-Wen Li🇨🇳 · Li-Sheng Geng🇨🇳
The strangeness $S = - 3$ and $- 4$ baryon-baryon interactions are investigated in the relativistic chiral effective field theory at leading order. First, the potentials are derived from the $S = - 1$ sector assuming that the corresponding low-energy constants are related to each other via SU(3) flavor symmetry. The comparison with the state-of-the-art lattice QCD simulations, show, however, that SU(3) flavor symmetry breaking effects can not be neglected. In order to take into account these effects, we redetermine two sets of low-energy constants by fitting to the lattice QCD data in the $ΞΣ$ and $ΞΞ$ channels respectively. The fitting results demonstrate that the lattice QCD $S$ -waves phase shifts for both channels can be described rather well. Without any additional free low-energy constants, the predicted phase shifts for the $^{3} D_{1}$ channel and the mixing angle $ε_{1}$ are also in qualitative agreement with the lattice QCD data for the $S = - 3$ channel, while the results for the $S = - 4$ channel remain to be checked by future lattice QCD simulations. With the so-obtained low-energy constants, the $S$ -wave scattering lengths and effective ranges are calculated for these two channels at the physical point. Finally, in combination with the $S = 0$ and $- 2$ results obtained in our previous works, we study the evolution of the irreducible representation $27$ in the baryon-baryon interactions as a function of increasing strangeness. It is shown that the attraction decreases dramatically as strangeness increases from $S = 0$ to $S = - 2$ , but then remains relatively stable until $S = - 4$ . The results indicate that the existence of bound states in the $ΞΣ$ and $ΞΞ$ channels is rather unlikely.
Comments:
9 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2011.05510 [pdf]
PRC(2021)·22 citations
02
[Submitted on 11 Nov 2020]
The subtle connection between shape coexistence and quantum phase transition. The Zr case
J.E. García-Ramos · K. Heyde
Background: Zr region is characterized by very rapid changes in the ground state structure of the nuclei. In particular, the onset of deformation when passing from $^{98}$ Zr to $^{100}$ Zr is one of the fastest ever observed in the nuclear chart. It has been probed both experimental and theoretically that certain low-lying excited states of Zr isotopes own different shapes than the ground state. Purpose: We intend to disentangle the interplay between the sudden changes in the ground state shape, i.e., the existence of a quantum phase transition, and the presence in the spectra of coexisting states with very different deformation, i.e., the presence of shape coexistence. Method: We rely on a previous calculation using the Interacting Boson Model with Configuration Mixing (IBM-CM) which reproduces in detail the spectroscopic properties of $^{96 - 110}$ Zr. This IBM-CM calculation allows to compute mean-field energy surfaces, wave functions and any other observable related with the presence of shape coexistence or with a quantum phase transition. Results: We obtain energy surfaces and the equilibrium value of the deformation parameter $β$ , the U(5) decomposition of the wave functions and the density of states. Conclusions: We confirm that Zr is a clear example of quantum phase transition that originates from the crossing of two configurations with a very different degree of deformation. Moreover, we observe how the intruder configuration exhibits its own evolution which resembles a quantum phase transition too.
Comments:
Accepted in Physical Review C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2011.05581 [pdf]
PRC(2020)·32 citations
03
[Submitted on 11 Nov 2020]
Neutron matter at finite temperature based on chiral effective field theory interactions
J. Keller · C. Wellenhofer · K. Hebeler · A. Schwenk
We study the equation of state of neutron matter at finite temperature based on two- and three-nucleon interactions derived within chiral effective field theory to next-to-next-to-next-to-leading order. The free energy, pressure, entropy, and internal energy are calculated using many-body perturbation theory including terms up to third order around the self-consistent Hartree-Fock solution. We include contributions from three-nucleon interactions without employing the normal-ordering approximation and provide theoretical uncertainty estimates based on an order-by-order analysis in the chiral expansion. Our results demonstrate that thermal effects can be captured remarkably well via a thermal index and a density-dependent effective mass. The presented framework provides the basis for studying the dense matter equation of state at general temperatures and proton fractions relevant for core-collapse supernovae and neutron star mergers.
Comments:
14 pages, 14 figures, minor changes, published version
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Experiment (nucl-ex)
arXiv:
2011.05855 [pdf]
PRC(2021)·66 citations
04
[Submitted on 9 Nov 2020] (cross-list from hep-th)
(Phenomenology/Lattice-Compatible) $S U (3)$ M $χ$ PT HD up to $O (p^{4})$ and the $O (R^{4})$ -Large- $N$ Connection
Vikas Yadav🇮🇳 · Gopal Yadav🇮🇳 · Aalok Misra🇮🇳
Obtaining the values of the coupling constants of the low energy effective theory corresponding to QCD, compatible with experimental data, even in the (vector) mesonic sector from (the $M$ -theory uplift of) a UV-complete string theory dual, has thus far been missing in the literature. We take the first step in this direction by obtaining the values of the coupling constants of the $O (p^{4})$ $χ$ PT Lagrangian in the chiral limit involving the NGBs and $ρ$ meson (and its flavor partners) from the $M$ -theory /type IIA dual of large- $N$ thermal QCD, inclusive of the $O (R^{4})$ corrections. We observe that ensuring compatibility with phenomenological/lattice results (the values ) as given in arXiv:1510.01634[hep-ph], requires a relationship relating the $O (R^{4})$ corrections and large- $N$ suppression. In other words, QCD demands that the higher derivative corrections and the large- $N$ suppressed corrections in its M/string theory dual are related. As a bonus, we explicitly show that the $O (R^{4})$ corrections in the UV to the $M$ -theory uplift of the type IIB dual of large- $N$ thermal QCD, can be consistently set to be vanishingly small.
Comments:
v2: 1+51 pages, LaTeX; Added refs and explanatory text- an app summarizing the HLS formalism (based on Harada and Yamawaki's Phys Rep review), an app on O(R^4) corrections in the D6-brane DBI action, a small discussion on holographic renormalization and a summary of results and a table (fitting the model-related parameters to phenomenological values of O(p^4) ChPT LECs); to appear in JHEP
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2011.04660 [pdf]
JHEP(2021)·17 citations
05
[Submitted on 10 Nov 2020] (cross-list from hep-th)
Many Phases of Generalized 3D Instanton Crystals
Matti Jarvinen🇮🇱 · Vadim Kaplunovsky🇺🇸 · Jacob Sonnenschein🇮🇱
Nuclear matter at large number of colors is necessarily in a solid phase. In particular holographic nuclear matter takes the form of a crystal of instantons of the flavor group. In this article we initiate the analysis of the three-dimensional crystal structures and the orientation patterns for the two-body potential that follows from holographic duality. The outcome of the analysis includes several unexpected results. We perform simulations of ensembles of O(10000) instantons whereby we identify the lattice structure and orientations for the different values of the weight factors of the non-Abelian orientation terms in the two-body potential. The resulting phase diagram is surprisingly complex, including a variety of ferromagnetic and antiferromagnetic crystals with various global orientation patterns, and various "non-Abelian" crystals where orientations have no preferred direction. The latter include variants of face-centered-cubic, hexagonal, and simple cubic crystals which may have remarkably large or small aspect ratios. The simulation results are augmented by analytic analysis of the long-distance divergences, and numerical computation of the (divergence free) energy differences between the non-Abelian crystals, which allows us to precisely determine the structure of the phase diagram.
Comments:
48 pages, 20 figures (including 5 interactive 3D figures). v3: minor comments and explanations added
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2011.05338 [pdf]
SciPost Phys.(2021)·11 citations
06
[Submitted on 10 Nov 2020] (cross-list from hep-ph)
W-boson production in TMD factorization
Daniel Gutierrez-Reyes🇪🇸 · Sergio Leal-Gomez🇦🇹 · Ignazio Scimemi🇪🇸
At hadron colliders, the differential cross section for $W$ production can be factorized and it is sensitive transverse momentum dependent distributions (TMD) for low boson transverse momentum. While, often, the corresponding non-perturbative QCD contributions are extrapolated from $Z$ boson production, here we use an existing extraction (based on the code Artemide) of TMD which includes data coming from Drell-Yan and semi-inclusive deep inelastic scattering, to provide checks and predictions for the $W$ case. Including fiducial cuts with different configurations and kinematical power corrections, we consider transverse momentum dependent cross sections within several intervals of the vector boson transverse mass. We perform the same study for the $p_{T}^{W^{-}} / p_{T}^{W^{+}}$ and $p_{T}^{Z} / p_{T}^{W}$ distributions. We compare our predictions with recent extractions of these quantities at ATLAS and CMS and results from TeVatron. The results encourage a broader experimental and phenomenological work, and a deeper study of TMD for the $W$ case.
Comments:
v3: version accepted for publication; table added, some plots revised
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2011.05351 [pdf]
EPJC(2021)·4 citations
07
[Submitted on 11 Nov 2020] (cross-list from hep-lat)
Relativistic three-particle quantization condition for nondegenerate scalars
Tyler D. Blanton🇺🇸 · Stephen R. Sharpe🇺🇸
The formalism relating the relativistic three-particle infinite-volume scattering amplitude to the finite-volume spectrum has been developed thus far only for identical or degenerate particles. We provide the generalization to the case of three nondegenerate scalar particles with arbitrary masses. A key quantity in this formalism is the quantization condition, which relates the spectrum to an intermediate K matrix. We derive three versions of this quantization condition, each a natural generalization of the corresponding results for identical particles. In each case we also determine the integral equations relating the intermediate K matrix to the three-particle scattering amplitude, $M_{3}$ . The version that is likely to be most practical involves a single Lorentz-invariant intermediate K matrix, $K_{df, 3}$ . The other versions involve a matrix of K matrices, with elements distinguished by the choice of which initial and final particles are the spectators. Our approach should allow a straightforward generalization of the relativistic approach to all other three-particle systems of interest.
Comments:
34 pages, 7 figures; v2: added section 2 providing general recipe for developing formalism; fixed typos; matches with published version
Subjects:
High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2011.05520 [pdf]
PRD(2021)·78 citations
08
[Submitted on 9 Nov 2020] (cross-list from quant-ph)
Wavefunction structure in quantum many-fermion systems with $k$ -body interactions: conditional $q$ -normal form of strength functions
V.K.B. Kota · Manan Vyas
For finite quantum many-particle systems modeled with say $m$ fermions in $N$ single particle states and interacting with $k$ -body interactions ( $k \leq m$ ), the wavefunction structure is studied using random matrix theory. Hamiltonian for the system is chosen to be $H = H_{0} (t) + λV (k)$ with the unperturbed $H_{0} (t)$ Hamiltonian being a $t$ -body operator and $V (k)$ a $k$ -body operator with interaction strength $λ$ . Representing $H_{0} (t)$ and $V (k)$ by independent Gaussian orthogonal ensembles (GOE) of random matrices in $t$ and $k$ fermion spaces respectively, first four moments, in $m$ -fermion spaces, of the strength functions $F_{κ} (E)$ are derived; strength functions contain all the information about wavefunction structure. With $E$ denoting the $H$ energies or eigenvalues and $κ$ denoting unperturbed basis states with energy $E_{κ}$ , the $F_{κ} (E)$ give the spreading of the $κ$ states over the eigenstates $E$ . It is shown that the first four moments of $F_{κ} (E)$ are essentially same as that of the conditional $q$ -normal distribution given in: P.J. Szabowski, Electronic Journal of Probability {\bf 15}, 1296 (2010). This naturally gives asymmetry in $F_{κ} (E)$ with respect to $E$ as $E_{κ}$ increases and also the peak value changes with $E_{κ}$ . Thus, the wavefunction structure in quantum many-fermion systems with $k$ -body interactions follows in general the conditional $q$ -normal distribution.
Comments:
23 pages, 3 figures
Subjects:
Quantum Physics (quant-ph); Mathematical Physics (math-ph); math.MP (math.MP); Nuclear Theory (nucl-th)
arXiv:
2011.05799 [pdf]
J.Stat.Mech.(2021)·4 citations
09
[Submitted on 11 Nov 2020] (cross-list from hep-ph)
Ballistic diffusion of heavy quarks in the early stage of relativistic heavy ion collisions at RHIC and LHC
Jun-Hong Liu🇨🇳 · Santosh K. Das🇮🇳 · Vincenzo Greco🇮🇹 · Marco Ruggieri🇨🇳
We study the diffusion of charm quarks in the early stage of high energy nuclear collisions at the RHIC and the LHC. The main novelty of the present study is the introduction of the color current carried by the heavy quarks that propagate in the evolving Glasma (Ev-Glasma), that is responsible of the energy loss via polarization of the medium. We compute the transverse momentum broadening, $σ_{p}$ , of charm in the pre-thermalization stage, and the impact of the diffusion on the nuclear modification factor in nucleus-nucleus collisions. The net effect of energy loss is marginal in the pre-thermalization stage. The study is completed by the calculation of coordinate spreading, $σ_{x}$ , and by a comparison with Langevin dynamics. $σ_{p}$ in Ev-Glasma overshoots the result of standard Langevin dynamics at the end of the pre-hydro regime. We interpret this as a result of memory of the color force acting on the charm quarks that implies $σ_{p} \propto t^{2}$ . Moreover, $σ_{x} \propto t^{2}$ in the pre-hydro stage shows that the charm quark in the Ev-Glasma is in the regime of ballistic diffusion.
Comments:
12 pages, 5 figures. In V2 we have corrected the presentation on how color charges are initialized in the code. A few clarifying comments have been added, to justify the use of the SU(2) color group, and to improve the presentation of the Langevin equation with the nonlocal dissipative kernel. V2 is the version accepted for publication on Phys. Rev. D
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2011.05818 [pdf]
PRD(2021)·34 citations
10
[Submitted on 11 Nov 2020] (cross-list from hep-ph)
Flavor-dependent radiative corrections in coherent elastic neutrino-nucleus scattering
Oleksandr Tomalak🇺🇸 · Pedro Machado🇺🇸 · Vishvas Pandey🇺🇸 · Ryan Plestid🇺🇸
We calculate coherent elastic neutrino-nucleus scattering cross sections on spin-0 nuclei (e.g. $^{40}$ Ar and $^{28}$ Si) at energies below 100 MeV within the Standard Model and account for all effects of permille size. We provide a complete error budget including uncertainties at nuclear, nucleon, hadronic, and quark levels separately as well as perturbative error. Our calculation starts from the four-fermion effective field theory to explicitly separate heavy-particle mediated corrections (which are absorbed by Wilson coefficients) from light-particle contributions. Electrons and muons running in loops introduce a nontrivial dependence on the momentum transfer due to their relatively light masses. These same loops, and those mediated by tau leptons, break the flavor universality because of mass-dependent electromagnetic radiative corrections. Nuclear physics uncertainties significantly cancel in flavor asymmetries resulting in subpercent relative errors. We find that for low neutrino energies, the cross section can be predicted with a relative precision that is competitive with neutrino-electron scattering. We highlight potentially useful applications of such a precise cross section prediction ranging from precision tests of the Standard Model, to searches for new physics and to the monitoring of nuclear reactors.
Comments:
42 pages, 6 figures, v2: journal version; references added; legends to figures added; definition of the weak charge extended; definition of the weak form factor simplified, typos corrected
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2011.05960 [pdf]
JHEP(2021)·90 citations

Affiliations

first authorsco-authorsvia INSPIRE