Nuclear Theory·nucl-th

Tuesday·January 1, 2019

14 papers—5 primary·9 cross-listed

06
[Submitted on 28 Dec 2018] (cross-list from hep-lat)
Lattice QCD and nuclear physics for searches of physics beyond the Standard Model
Emanuele Mereghetti🇺🇸
Low-energy tests of fundamental symmetries are extremely sensitive probes of physics beyond the Standard Model, reaching scales that are comparable, if not higher, than directly accessible at the energy frontier. The interpretation of low-energy precision experiments and their connection with models of physics beyond the Standard Model relies on controlling the theoretical uncertainties induced by the nonperturbative nature of QCD at low energy and of the nuclear interactions. In these proceedings, I will discuss how the interplay of Lattice QCD and nuclear Effective Field Theories can lead to improved predictions for low-energy experiments, with controlled uncertainties. I will describe the framework of chiral Effective Field Theory, and then discuss a few examples, including non-standard $β$ decays, neutrinoless double beta decay and searches for electric dipole moments, to highlight the progress achieved in recent years, and the role that Lattice QCD will play in addressing the remaining open problems.
Comments:
10 pages, 1 figure. Presented at the 36th International Symposium on Lattice Field Theory (Lattice 2018)
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1812.11238 [pdf]
PoS(2019)·2 citations
07
[Submitted on 29 Dec 2018] (cross-list from hep-th)
Magneto-transport in an anomalous fluid with weakly broken symmetries, in weak and strong regime
Navid Abbasi🇮🇷 · Armin Ghazi🇮🇷 · Farid Taghinavaz🇮🇷 · Omid Tavakol🇮🇷
We consider a general system with weakly broken time and translation symmetries. We assume the system also possesses a $U (1)$ symmetry which is not only weakly broken, but is anomalous. We use the second order chiral quasi-hydrodynamics to compute the magneto-conductivities in the system in the presence of a weak magnetic field. Analogous to electrical and thermoelectric conductivities, it turns out that the thermal conductivity is identified with a coefficient which depends on the mixed gauge-gravitational anomaly. By applying our general formulas to a free system of Weyl fermions at low temperature limit $T ≪ μ$ , we find that our system is Onsager reciprocal if the relaxation in all energy, momentum and charge channels occurs at the same rate. In the high temperature limit $T ≫ μ$ , we consider a strongly coupled $S U (N_{c})$ gauge theory with $N_{c} ≫ 1$ in the hydrodynamic limit. Its gravity dual is a magnetized charged brane to which, we apply our formulas and compute the conductivities. On the way, we show that analogous to the weak regime, an energy cut-off emerges to regulate the thermodynamic quantities. From this gravity background we also find the coefficients of chiral magnetic effect in agreement with the well-known result of the Son-Surowka.
Comments:
36 pages, v2: journal version; references added
Subjects:
High Energy Physics — Theory (hep-th); Strongly Correlated Electrons (cond-mat.str-el); Nuclear Theory (nucl-th)
arXiv:
1812.11310 [pdf]
JHEP(2019)·12 citations
08
[Submitted on 29 Dec 2018] (cross-list from hep-ph)
Particle Yields and Ratios within Equilibrium and Non-Equilibrium Statistics
Abdel Nasser Tawfik (Nile U., Cairo & Egyptian Ctr. Theor. Phys., Cairo & WLCAPP, Cairo)🇪🇬 · Hayam Yassin🇪🇬 · Eman R. Abo Elyazeed (Ain Shams U., Cairo & Egyptian Ctr. Theor. Phys., Cairo & WLCAPP, Cairo)🇪🇬
In characterizing the yields and ratios various of well identified particles in the ALICE experiment, we utilize extensive {\it additive} thermal approaches, to which various missing states of the hadron resonances are taken into consideration, as well. Despite some non-equilibrium conditions that are slightly driving this statistical approach away from equilibrium, the approaches are and remain additive and extensive. Besides van der Waals repulsive interactions (assuming that the gas constituents are no longer point-like, i.e. finite-volume corrections taken into consideration), finite pion chemical potentials as well as perturbations to the light and strange quark occupation factors are taken into account. When confronting our calculations to the ALICE measurements, we conclude that the proposed conditions for various aspects deriving the system out of equilibrium notably improve the reproduction of the experimental results, i.e. improving the statistical fits, especially the finite pion chemical potential. This points out to the great role that the non-equilibrium pion production would play, and the contributions that the hadron resonance missing states come up with, even when the principles of statistical extensivity and additivity aren't violated. These results seem to propose revising the conclusions propagated by most of the field, that the produced particles quickly reach a state of local equilibrium leading to a collective expansion often described by fluid dynamics. This situation seems not remaining restrictively valid, at very large collision energies.
Comments:
15 pages, 4 figures, submitted to EPL
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1812.11347 [pdf]
EPL(2019)·3 citations
09
[Submitted on 29 Dec 2018] (cross-list from quant-ph)
Nuclear quantum memory and time sequencing of a single $γ$ photon
Xiwen Zhang🇺🇸 · Wen-Te Liao🇺🇸 · Alexey Kalachev🇷🇺 · Rustem Shakhmuratov🇷🇺 · Marlan Scully🇺🇸 · Olga Kocharovskaya🇺🇸
A $γ$ -ray-nuclear quantum interface is suggested as a new platform for quantum information processing, motivated by remarkable progresses in $γ$ -ray quantum optics. The main advantages of a $γ$ photon over an optical photon lie in its almost perfect detectability and much tighter, potentially sub-angstrom, focusability. Nuclear ensembles hold important advantages over atomic ensembles in a unique combination of high nuclear density in bulk solids with narrow, lifetime-broadening Mössbauer transitions even at room temperature. This may lead to the densest long-lived quantum memories and the smallest size photon processors. Here we propose a technique for $γ$ photon quantum memory through a Doppler frequency comb, produced by a set of resonantly absorbing nuclear targets that move with different velocities. It provides a reliable storage, an on-demand generation, and a time sequencing of a single $γ$ photon. This scheme presents the first $γ$ -photon-nuclear-ensemble interface opening a new direction of research in quantum information science.
Subjects:
Quantum Physics (quant-ph); Nuclear Theory (nucl-th)
arXiv:
1812.11441 [pdf]
PRL(2019)·17 citations
10
[Submitted on 30 Dec 2018] (cross-list from cond-mat.quant-gas)
Efimov physics beyond three particles
Betzalel Bazak🇮🇱
Efimov physics originally refers to a system of three particles. Here we review recent theoretical progress seeking for manifestations of Efimov physics in systems composed of more than three particles. Clusters of more than three bosons are tied to each Efimov trimer, but no independent Efimov physics exists there beyond three bosons. The case of a few heavy fermions interacting with a lighter atom is also considered, where the mass ratio of the constituent particles plays a significant role. Following Efimov's study of the (2+1) system, the (3+1) system was shown to have its own critical mass ratio to become Efimovian. We show that the (4+1) system becomes Efimovian at a mass ratio which is smaller than its sub-systems thresholds, giving a pure five-body Efimov effect. The (5+1) and (6+1) systems are also discussed, and we show the absence of 6- and 7-body Efimov physics there.
Subjects:
Quantum Gases (cond-mat.quant-gas); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
1812.11499 [pdf]
Springer Proc.Phys.(2020)·0 citations
11
[Submitted on 30 Dec 2018] (cross-list from hep-ph)
Early time dynamics and hard probes in heavy-ion collisions
S. Schlichting🇩🇪
We present an overview of the current state of understanding of the early time dynamics of high-energy heavy-ion collisions, emphasizing recent developments and connections between the physics of the initial state and that of hard probes in heavy-ion collisions. Based on a weak-coupling description, we first establish a microscopic picture of the early time dynamics and equilibration process and subsequently discuss their macroscopic manifestations along with a novel macroscopic description of the pre-equilibrium phase. Some phenomenological consequences concerning the role of the pre-equilibrium phase in large (AA) and small (pp/pA) collision systems are briefly discussed along with open questions and opportunities for future improvements.
Comments:
Proceedings of the Hard Probes 2018 conference, 30 Sept. - 5 Oct. 2018, Aix-les-Bains, France; 8 pages, 4 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1812.11529 [pdf]
PoS(2019)·2 citations
12
[Submitted on 30 Dec 2018] (cross-list from hep-ph)
Jet fragmentation in a QCD medium: Universal quark/gluon ration and Wave turbulence
Y. Mehtar-Tani🇺🇸 · S. Schlichting🇩🇪
We calculate the evolution of a jet shower due to medium induced splittings in the deep LPM regime. Due to the characteristic energy dependence of the formation time $t_{form} (ω) = ω / q ˉ^$ , the radiative break-up process exhibits turbulent characteristics, allowing for analytic predictions of various inclusive properties of the medium induced cascade in an inertial range of energies $T ≪ ω ≪ E$ , where $E$ is the energy of the jet and $T$ is the temperature of the medium.
Comments:
Proceedings of the Hard Probes 2018 conference, 30 Sept. - 5 Oct. 2018, Aix-les-Bains, France; 4 pages, 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1812.11533 [pdf]
PoS(2018)·0 citations
13
[Submitted on 31 Dec 2018] (cross-list from hep-ph)
Mesonic Condensation in Isospin Matter under Rotation
Hui Zhang🇨🇳 · Defu Hou🇨🇳 · Jinfeng Liao🇺🇸
We investigate the mesonic condensation in isospin matter under rotation. Using the two-flavor NJL effective model under the presence of global rotation, we demonstrate two important effects of the rotation on its phase structure: a rotational suppression of the scalar-channel condensates, in particular the pion condensation region; and a rotational enhancement of the rho condensation region with vector-channel condensate. A new phase diagram for isospin matter under rotation is mapped out on the $ω - μ_{I}$ plane where three distinctive phases, corresponding to $σ$ , $π$ , $ρ$ dominated regions respectively, are separated by a second-order line at low isospin chemical potential and a first-order line at high rotation which are further connected at a tri-critical point.
Comments:
6 pages, 4 figures, v3: FIG.4 is replaced
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1812.11787 [pdf]
CPC(2020)·54 citations
14
[Submitted on 31 Dec 2018] (cross-list from hep-lat)
The path from finite to infinite volume: Hadronic observables from lattice QCD
Zohreh Davoudi🇺🇸
Standard Model determinations of properties of strongly interacting systems of hadrons have become possible with the powerful method of lattice quantum chromodynamics (LQCD), a method with growing applicability and reliability. While growth in computational power and innovations in algorithmic and computational approaches have been essential in advancing the state of the field, conceptual and formal developments have played a crucial role in turning the output of LQCD computations to phenomenologically valuable results. From the invention of finite-volume technology to access physical observables by Martin Lüscher over three decades ago to date, this field has grown in scope and complexity, enabling studies of scattering amplitudes and reaction rates, as well as spectroscopy of excited states of quantum chromodynamics (QCD) and resonances. Further, LQCD studies are augmented with the inclusion of quantum electrodynamics (QED), and subtleties related to the finite volume of systems in presence of QED have been understood and largely controlled. In this talk, I focus on selected developments to give a taste of the status of the field concerning the mapping between the finite and infinite-volume physics and its state-of-the-art applications.
Comments:
24 pages, 12 figures. Talk presented at the 36th International Symposium on Lattice Field Theory (LATTICE2018), 22-28 July, 2018, Michigan State University, East Lansing, MI, USA. Version with extended references
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1812.11899 [pdf]
PoS(2018)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE