Thu·Jun 17, 2021Thursday·June 17, 2021

1. 01*

   Locating the critical endpoint of QCD: mesonic backcoupling effects

   Pascal J. Gunkel🇩🇪 · Christian S. Fischer🇩🇪

   We study the effects of pion and sigma meson backcoupling on the chiral order parameters and the QCD phase diagram and determine their effect on the location of the chiral critical endpoint. To this end, we solve a coupled set of truncated Dyson--Schwinger equations for Landau gauge quark and gluon propagators with $N_f=2+1$ dynamical quark flavors and explicitly backcoupled mesons. The corresponding meson bound-state properties and the quark-meson Bethe--Salpeter vertices are obtained from their homogeneous Bethe--Salpeter equation. We find chiral-restoration effects of the pion and/or sigma meson backcoupling and observe a (small) shift of the critical endpoint towards smaller chemical potentials. The curvature of the chiral crossover line decreases. Our results indicate that the location of the critical endpoint in the phase diagram is mainly determined by the microscopic degrees of freedom of QCD (in contrast to its critical properties).

   hep-phPRD(2021)·160 citations
2. 02*

   Regarding the distribution of glue in the pion

   Lei Chang🇨🇳 · Craig D. Roberts🇨🇳

   Understanding why the scale of emergent hadron mass is obvious in the proton but hidden in the pion may rest on mapping the distribution functions (DFs) of all partons within the pion and comparing them with those in the proton; and since glue provides binding in quantum chromodynamics, the glue DF could play a special role. Producing reliable predictions for the proton's DFs is difficult because the proton is a three valence-body bound-state problem. As sketched herein, the situation for the pion, a two valence-body problem, is much better, with continuum and lattice predictions for the valence-quark and glue DFs in agreement. This beginning of theory alignment is timely because experimental facilities now either in operation or planning promise to realise the longstanding goal of providing pion targets, thereby enabling precision experimental tests of rigorous theory predictions concerning Nature's most fundamental Nambu-Goldstone bosons.

   hep-phhep-exhep-latnucl-ex+1Chin.Phys.Lett.(2021)·31 citations
3. 03*

   Langevin dynamics of heavy quarks in a soft-hard factorized approach

   Shuang Li🇨🇳 · Fei Sun🇨🇳 · Wei Xie🇨🇳 · Wei Xiong🇨🇳

   By utilizing a soft-hard factorized model, which combines a thermal perturbative description of soft scatterings and a perturbative QCD-based calculation for hard collisions, we study the energy and temperature dependence of the heavy quark diffusion coefficients in Langevin dynamics. The adjustable parameters are fixed from the comprehensive model-data comparison. We find that a small value of the spatial diffusion coefficient at transition temperature is preferred by data $2\pi T{D}_s(T_c)\simeq 6$. With the parameter-optimized model, we are able to describe simultaneously the prompt $D^0$ $R_{\mathrm{AA}}$ and $v_2$ data at $p_{\mathrm{T}}\le 8$ GeV in Pb--Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ and $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV. We also make predictions for non-prompt $D^0$ meson for future experimental tests down to the low momentum region.

   hep-phnucl-thEPJC(2021)·7 citations
4. 04*

   Dynamical measurements of deviations from Newton's $1/r^2$ law

   J. Baeza-Ballesteros🇪🇸 · A. Donini🇪🇸 · S. Nadal-Gisbert🇪🇸

   In a previous work (arXiv:1609.05654v2), an experimental setup aiming at the measurement of deviations from the Newtonian $1/r^2$ distance dependence of gravitational interactions was proposed. The theoretical idea behind this setup was to study the trajectories of a "Satellite" with a mass $m_{\mathrm{S}}\sim \mathcal{O}(10^{-9})$ $\mathrm{g}$ around a "Planet" with mass $m_{\mathrm{P}}\in [10^{-7},10^{-5}]$ $\mathrm{g}$, looking for precession of the orbit. The observation of such feature induced by gravitational interactions would be an unambiguous indication of a gravitational potential with terms different from $1/r$ and, thus, a powerful tool to detect deviations from Newton's $1/r^2$ law. In this paper we optimize the proposed setup in order to achieve maximal sensitivity to look for {\em Beyond-Newtonian} corrections. We study in detail possible background sources that could induce precession and quantify their impact on the achievable sensitivity. We conclude that a dynamical measurement of deviations from newtonianity can test Yukawa-like corrections to the $1/r$ potential with strength as low as $\alpha \sim 10^{-2}$ for distances as small as $\lambda \sim 10\mu \mathrm{m}$.

   hep-phgr-qchep-exEPJC(2022)·9 citations
5. 05*

   Virtual QCD corrections to gluon-initiated diphoton plus jet production at hadron colliders

   Simon Badger🇮🇹 · Christian Brønnum-Hansen🇩🇪 · Dmitry Chicherin🇫🇷 · Thomas Gehrmann🇨🇭 · Heribertus Bayu Hartanto🇬🇧 · Johannes Henn🇩🇪 · Matteo Marcoli🇨🇭 · Ryan Moodie🇬🇧 · Tiziano Peraro🇮🇹 · Simone Zoia🇮🇹

   We present an analytic computation of the gluon-initiated contribution to diphoton plus jet production at hadron colliders up to two loops in QCD. We reconstruct the analytic form of the finite remainders from numerical evaluations over finite fields including all colour contributions. Compact expressions are found using the pentagon function basis. We provide a fast and stable implementation for the colour- and helicity-summed interference between the one-loop and two-loop finite remainders in C++ as part of the NJet library.

   hep-phhep-thJHEP(2021)·101 citations
6. 06*

   The Radial Excited Heavy Mesons

   Muyang Chen🇨🇳

   In this paper, the first radial excited heavy pseudoscalar and vector mesons (${\eta }_c(2S)$, $\psi (2S)$, $B_c(2S)$, $B_c^{\ast }(2S)$, ${\eta }_b(2S)$, ${\rm Y}(2S)$) are studied in the Dyson-Schwinger equation and Bethe-Salpeter equation approach. It is showed that the effective interactions of the radial excited states are harder than that of the ground states. With the interaction well determined by fitting the masses and leptonic decay constants of $\psi (2S)$ and ${\rm Y}(2S)$, the first radial excited heavy mesons could be quantitatively described in the rainbow ladder approximation. The masses and leptonic decay constants of ${\eta }_c(2S)$, $B_c(2S)$, $B_c^{\ast }(2S)$ and ${\eta }_b(2S)$ are predicted.

   hep-phnucl-thCPC(2021)·3 citations
7. 07*

   Astrophysical Searches and Constraints on Ultralight Bosonic Dark Matter

   David J. E. Marsh🇬🇧 · Sebastian Hoof🇩🇪

   Starting from the evidence that dark matter indeed exists and permeates the entire cosmos, various bounds on its properties can be estimated. Beginning with the cosmic microwave background and large scale structure, we summarize bounds on the ultralight bosonic dark matter (UBDM) mass and cosmic density. These bounds are extended to larger masses by considering galaxy formation and evolution, and the phenomenon of black hole superradiance. We then discuss the formation of different classes of UBDM compact objects including solitons/axion stars and miniclusters. Next, we consider astrophysical constraints on the couplings of UBDM to Standard Model particles, from stellar cooling (production of UBDM) and indirect searches (decays or conversion of UBDM). Throughout, there are short discussions of "hints and opportunities" in searching for UBDM in each area.

   hep-phastro-ph.COastro-ph.GA21 citations
8. 08*

   Long Dead Winos

   Mark D. Goodsell🇫🇷 · Lakshmi Priya🇮🇳

   We describe a new code and approach using particle-level information to recast the recent CMS disappearing track searches including all run 2 data. Notably, the simulation relies on knowledge of the detector geometry, and we also include the simulation of pileup events directly rather than as an efficiency function. We validate it against provided acceptances and cutflows, and use it in combination with heavy stable charged particle searches to place limits on winos with any proper decay length above a centimetre. We also provide limits for a simple model of a charged scalar that is only produced in pairs, that decays to electrons plus an invisible fermion.

   hep-phEPJC(2022)·14 citations
9. 09*

   Deep Learning for the Classification of Quenched Jets

   L. Apolinário🇵🇹 · N. F. Castro🇵🇹 · M. Crispim Romão🇵🇹 · J. G. Milhano🇵🇹 · R. Pedro🇵🇹 · F. C. R. Peres🇵🇹

   An important aspect of the study of Quark-Gluon Plasma (QGP) in ultra-relativistic collisions of heavy ions is the ability to identify, in experimental data, a subset of the jets that were strongly modified by the interaction with the QGP. In this work, we propose studying deep learning techniques for this purpose. Samples of $Z+$jet events were simulated in vacuum and medium and used to train deep neural networks with the objective of discriminating between medium- and vacuum-like jets. Dedicated Convolutional Neural Networks, Dense Neural Networks and Recurrent Neural Networks were developed and trained, and their performance was studied. Our results show the potential of these techniques for the identification of jet quenching effects induced by the presence of the QGP.

   hep-phhep-exphysics.comp-phJHEP(2021)·35 citations
10. 10*

    Mass corrections to the hard thermal/dense loops

    Marc Comadran🇪🇸 · Cristina Manuel🇪🇸

    We compute corrections to the hard thermal (or dense) loop photon polarization tensor associated to a small mass $m$ of the fermions of an electromagnetic plasma at high temperature $T$ (or chemical potential $\mu$). To this aim we use the on-shell effective field theory, amended with mass corrections. We also carry out the computation using transport theory, reaching to the same result. Interemediate steps in the computations reveal the presence of potential infrared divergencies. We use dimensional regularization, as it is respectful with the gauge symmetry, and then show that all infrared divergencies cancel in the final result. We compare the mass corrections with both the power and two-loop corrections, and claim that they are equally important if the mass is soft, that is, of order $eT$ (or $e\mu$), where $e$ is the gauge coupling constant, but are dominat if the mass obeys $eT<m\ll T$ (or $e\mu <m\ll \mu )$.

    hep-phPRD(2021)·8 citations
11. 11*

    An effective field theory of the Delta-resonance

    Juan Carlos Criado🇬🇧 · Abdelhak Djouadi🇪🇸 · Niko Koivunen🇪🇪 · Kristjan Müürsepp🇪🇪 · Martti Raidal🇪🇪 · Hardi Veermäe🇪🇪

    We present an effective field theory of the $\Delta$-resonance as an interacting Weinberg's $(3/2,0)\oplus (0,3/2)$ field in the multi-spinor formalism. We derive its interactions with nucleons $N$, pions $\pi$ and photons $\gamma$, and compute the $\Delta$-resonance cross-sections in pion-nucleon scattering and pion photo-production. The theory contains only the physical spin-3/2 degrees of freedom. Thus, it is intrinsically consistent at the Hamiltonian level and, unlike the commonly used Rarita-Schwinger framework, does not require any additional ad hoc manipulation of couplings or propagators. The symmetries of hadronic physics select a unique operator for each coupling $N\pi \Delta$ and $\gamma \pi \Delta$. The proposed framework can be extended to also describe other higher-spin hadronic resonances.

    hep-phnucl-th5 citations
12. 12*

    Stellar Shocks From Dark Matter Asteroid Impacts

    Anirban Das🇺🇸 · Sebastian A. R. Ellis🇺🇸 · Philip C. Schuster🇺🇸 · Kevin Zhou🇺🇸

    Macroscopic dark matter is almost unconstrained over a wide "asteroid-like" mass range, where it could scatter on baryonic matter with geometric cross section. We show that when such an object travels through a star, it produces shock waves which reach the stellar surface, leading to a distinctive transient optical, UV and X-ray emission. This signature can be searched for on a variety of stellar types and locations. In a dense globular cluster, such events occur far more often than flare backgrounds, and an existing UV telescope could probe orders of magnitude in dark matter mass in one week of dedicated observation.

    hep-phastro-ph.COastro-ph.HEastro-ph.SRPRL(2022)·18 citations
13. 13*

    Vacuum stability with radiative Yukawa couplings

    Emidio Gabrielli🇮🇹 · Luca Marzola🇪🇪 · Kristjan Müürsepp🇪🇪 · Ruiwen Ouyang🇪🇪

    We explore the electroweak vacuum stability in the framework of a recently proposed paradigm for the origin of Yukawa couplings. These arise as low energy effective couplings radiatively generated by portal interactions with a hidden, or dark, sector at the one-loop level. Possible tree-level Yukawa couplings are forbidden by a new underlying symmetry, assumed to be spontaneously broken by the vacuum expectation value of a new scalar field above the electroweak scale. As a consequence, the top Yukawa interaction ceases to behave as a local operator at energies above the new sector scale and, therefore, cannot contribute to the running of the quartic Higgs coupling at higher energies. By studying two complementary scenarios, we explicitly show that the framework can achieve the stability of the electroweak vacuum without particular tuning of parameters. The proposed mechanism requires the existence of a dark sector and new portal messenger scalar interactions that, connecting the Standard Model to the dark sector fields, could be tested at the LHC and future collider experiments.

    hep-phJHEP(2022)·4 citations
14. 14*

    Cannibalism's lingering imprint on the matter power spectrum

    Adrienne L. Erickcek🇺🇸 · Pranjal Ralegankar🇺🇸 · Jessie Shelton🇺🇸

    The early universe may have contained internally thermalized dark sectors that were decoupled from the Standard Model. In such scenarios, the relic dark thermal bath, composed of the lightest particle in the dark sector, can give rise to an epoch of early matter domination prior to Big Bang Nucleosynthesis, which has a potentially observable impact on the smallest dark matter structures. This lightest dark particle can easily and generically have number-changing self-interactions that give rise to "cannibal" behavior. We consider cosmologies where an initially sub-dominant cannibal species comes to temporarily drive the expansion of the universe, and we provide a simple map between the particle properties of the cannibal species and the key features of the enhanced dark matter perturbation growth in such cosmologies. We further demonstrate that cannibal self-interactions can determine the small-scale cutoff in the matter power spectrum even when the cannibal self-interactions freeze out prior to cannibal domination.

    hep-phastro-ph.COJCAP(2022)·33 citations
15. 15*

    Quantum simulation of non-equilibrium dynamics and thermalization in the Schwinger model

    Wibe A. de Jong🇺🇸 · Kyle Lee🇺🇸 · James Mulligan🇺🇸 · Mateusz Płoskoń🇺🇸 · Felix Ringer🇺🇸 · Xiaojun Yao🇺🇸

    We present simulations of non-equilibrium dynamics of quantum field theories on digital quantum computers. As a representative example, we consider the Schwinger model, a 1+1 dimensional U(1) gauge theory, coupled through a Yukawa-type interaction to a thermal environment described by a scalar field theory. We use the Hamiltonian formulation of the Schwinger model discretized on a spatial lattice. With the thermal scalar fields traced out, the Schwinger model can be treated as an open quantum system and its real-time dynamics are governed by a Lindblad equation in the Markovian limit. The interaction with the environment ultimately drives the system to thermal equilibrium. In the quantum Brownian motion limit, the Lindblad equation is related to a field theoretical Caldeira-Leggett equation. By using the Stinespring dilation theorem with ancillary qubits, we perform studies of both the non-equilibrium dynamics and the preparation of a thermal state in the Schwinger model using IBM's simulator and quantum devices. The real-time dynamics of field theories as open quantum systems and the thermal state preparation studied here are relevant for a variety of applications in nuclear and particle physics, quantum information and cosmology.

    ↳ quant-phhep-lathep-phnucl-thPRD(2022)·145 citations
16. 16*

    Mass gap for a monopole interacting with a nonlinear spinor field

    V. Dzhunushaliev🇰🇿 · N. Burtebayev🇰🇿 · V. Folomeev🇰🇬 · J. Kunz🇩🇪 · A. Serikbolova🇰🇿 · A. Tlemisov🇰🇿

    Within SU(2) Yang-Mills theory with a source of the non-Abelian gauge field in the form of a classical spinor field, we study the dependence of the mass gap on the coupling constant between the gauge and nonlinear spinor fields. It is shown that the total dimensionless energy of the monopole interacting with the nonlinear spinor fields depends only on the dimensionless coupling constant.

    ↳ hep-thhep-phPRD(2021)·8 citations
17. 17*

    Electroweak monopoles with a non-linearly realized weak hypercharge

    P. De Fabritiis🇧🇷 · J. A. Helayël-Neto🇧🇷

    We present a finite-energy electroweak-monopole solution obtained by considering non-linear extensions of the hypercharge sector of the Electroweak Theory, based on logarithmic and exponential versions of electrodynamics. We find constraints for a class of non-linear extensions and also work out an estimate for the monopole mass in this scenario. We finally derive a lower bound for the energy of the monopole and discuss the simpler case of a Dirac magnetic charge.

    ↳ hep-thhep-phEPJC(2021)·5 citations
18. 18*

    Domain Wall Fermions on the Brane

    Jesus Cruz Rojas🇬🇧 · Nick Evans🇬🇧 · Jack Mitchell🇬🇧

    We study domain wall fermions and their condensation in the D3/probe D7 system. A spatially dependent mass term for the N=2 hypermultiplet can be arranged to isolate distinct two component fermions on two 2+1 dimensional domain walls. We argue that the system shows condensation/mass generation analogous to the D3/probe D5 anti-D5 system. The chiral condensate and pion mass can be directly computed on the domain wall. We provide evidence that these systems with the domains separated by a width w have a bare (current) quark mass that scales as 1/w when the spatial dependent mass is large. Adding a magnetic field does not induce chiral symmetry breaking between the separated domain wall fermions, but a similar phenomenological dilaton factor can be made strong enough to introduce spontaneous symmetry breaking. We show a Gell-Man-Oakes-Renner relation for the pions in that case and also for the case where the D7 probe is in a back-reacted dilaton flow geometry. The vacuum configurations can also be interpreted as having a spontaneously generated mass by a Nambu-Jona-Lasinio four fermion operator, depending on the choice of boundary conditions on fluctuations, according to Witten's multi-trace prescription.

    ↳ hep-thhep-lathep-phPRD(2021)·3 citations
19. 19*

    Shape of atomic nuclei in heavy ion collisions

    Jiangyong Jia🇺🇸

    In the hydrodynamic model description of heavy ion collisions, the final-state anisotropic flow $v_n$ are linearly related to the strength of the multi-pole shape of the distribution of nucleons in the transverse plane ${\epsilon }_n$, $v_n\propto {\epsilon }_n$. The ${\epsilon }_n$, for $n=1,2,3,4$, are sensitive to the shape of the colliding ions, characterized by the quadrupole ${\beta }_2$, octupole ${\beta }_3$ and hexadecapole ${\beta }_4$ deformations. This sensitivity is investigated analytically and also in a Monte Carlo Glauber model. One observes a robust linear relation, $⟨{\epsilon }_n^2⟩=a_n^{\prime }+b_n^{\prime }{\beta }_n^2$, for events in a fixed centrality. The $⟨{\epsilon }_1^2⟩$ has a contribution from ${\beta }_3$ and ${\beta }_4$, and $⟨{\epsilon }_3^2⟩$ from ${\beta }_4$. In the ultra-central collisions, there are little cross contributions between ${\beta }_2$ and ${\epsilon }_3$ and between ${\beta }_3$ and ${\epsilon }_2$, but clear cross contributions are present in non-central collisions. Additionally, $⟨{\epsilon }_n^2⟩$ are insensitive to non-axial shape parameters such as the triaxiality. This is good news because the measurements of $v_2$, $v_3$ and $v_4$ can be used to constrain simultaneously the ${\beta }_2$, ${\beta }_3$, and ${\beta }_4$ values. This is best done by comparing two colliding ions with similar mass numbers and therefore nearly identical $a_n^{\prime }$, to obtain simple equation that relates the ${\beta }_n$ of the two species. This opens up the possibility to map the shape of the atomic nuclei at a timescale ($<10^{-24}$s) much shorter than probed by low-energy nuclear structure physics ($<10^{-21}$s), which ultimately may provide information complementary to those obtained in the nuclear structure experiments.

    ↳ nucl-thhep-phnucl-exPRC(2022)·122 citations
20. 20*

    Neutron Spin Structure from e-3He Scattering with Double Spectator Tagging at the Electron-Ion Collider

    Ivica Friscic🇺🇸 · Dien Nguyen🇺🇸 · Jackson Pybus🇺🇸 · Alex Jentsch🇺🇸 · Efrain Segarra🇺🇸 · Mark Baker🇺🇸 · Or Hen🇺🇸 · Douglas Higinbotham🇺🇸 · Richard Milner🇺🇸 · Arun Tadepalli🇺🇸 · Zhoudunming Tu🇺🇸 · Jennifer Rittenhouse West🇺🇸

    The spin structure function of the neutron is traditionally determined by measuring the spin asymmetry of inclusive electron deep inelastic scattering (DIS) off polarized3He nuclei. In such experiments, nuclear effects can lead to large model dependencies in the interpretation of experimental data. Here we study the feasibility of suppressing such model dependencies by tagging both spectator protons in the process of DIS off neutrons in3He at the forthcoming Electron-Ion Collider (EIC). This allows reconstructing the momentum of the struck neutron to ensure it was nearly at rest in the initial state, thereby reducing sensitivity to nuclear corrections, and suppress contributions from electron DIS off protonsin3He. Using realistic accelerator and detector configurations, we find that the EIC can probe the neutron spin structure from xB of 0.003 to 0.651. We further find that the double spectator tagging method results in reduced uncertainties bya factor of 4 on the extracted neutron spin asymmetries over all kinematics, and by a factor of 10 in the low-xB region,thereby providing valuable insight to the spin and flavor structure of nucleons

    ↳ nucl-exhep-phPLB(2021)·16 citations
21. 21*

    Axion clouds may survive the perturbative tidal interaction over the early inspiral phase of black hole binaries

    Takuya Takahashi🇯🇵 · Takahiro Tanaka🇯🇵

    Gravitational wave observation has the potential of probing ultralight bosonic fields such as axion. Axion forms a cloud around a rotating black hole (BH) by superradiant instability and should affect the gravitational waveform from binary BHs. On the other hand, considering the cloud associated with a BH in a binary system, tidal interaction depletes the cloud in some cases during the inspiral phase. We made the exhaustive study of cloud depletion numerically in a wide parameter range for equal mass binaries, assuming only the quadrupolar tidal perturbation is at work. We found that clouds can avoid disappearing due to the tidal effect only when $l=1$ mode is the fastest growing mode and when the binary orbit is counter-rotating in the non-relativistic parameter region.

    ↳ gr-qcastro-ph.COhep-phJCAP(2021)·34 citations
22. 22*

    A sufficient condition for counterexamples to the Nelson-Seiberg theorem

    Zheng Sun🇨🇳 · Zipeng Tan🇨🇳 · Lu Yang🇨🇳

    Several counterexample models to the Nelson-Seiberg theorem have been discovered in previous literature, with generic superpotentials respecting the R-symmetry and non-generic R-charge assignments for chiral fields. This work present a sufficient condition for such counterexample models: The number of R-charge 2 fields, which is greater than the number of R-charge 0 fields, must be less than or equal to the number of R-charge 0 fields plus the number of independent field pairs with opposite R-charges and satisfying some extra requirements. We give a correct count of such field pairs when there are multiple field pairs with degenerated R-charges. These models give supersymmetric vacua with spontaneous R-symmetry breaking, thus are counterexamples to both the Nelson-Seiberg theorem and its extensions.

    ↳ hep-thhep-phJHEP(2021)·8 citations
23. 23*

    Polarization tensor of magnetized quark-gluon plasma at nonzero baryon density

    Xinyang Wang🇨🇳 · Igor Shovkovy🇺🇸

    We derive a general expression for the absorptive part of the one-loop photon polarization tensor in a strongly magnetized quark-gluon plasma at nonzero baryon chemical potential. To demonstrate the application of the main result in the context of heavy-ion collisions, we study the effect of a nonzero baryon chemical potential on the photon emission rate. The rate and the ellipticity of photon emission are studied numerically as a function the transverse momentum (energy) for several values of temperature and chemical potential. When the chemical potential is small compared to the temperature, the rates of the quark and antiquark splitting processes (i.e., $q\to q+\gamma$ and $\bar{q}\to \bar{q}+\gamma$, respectively) are approximately the same. However, the quark splitting gradually becomes the dominant process with increasing the chemical potential. We also find that increasing the chemical potential leads to a growing total photon production rate but has only a small effect on the ellipticity of photon emission. The quark-antiquark annihilation ($q+\bar{q}\to \gamma$) also contributes to the photon production, but its contribution remains relatively small for a wide range of temperatures and chemical potentials investigated.

    ↳ nucl-thhep-phhep-thEPJC(2021)·27 citations
24. 24*

    Gauge protection in non-Abelian lattice gauge theories

    Jad C. Halimeh🇮🇹 · Haifeng Lang🇮🇹 · Philipp Hauke🇮🇹

    Protection of gauge invariance in experimental realizations of lattice gauge theories based on energy-penalty schemes has recently stimulated impressive efforts both theoretically and in setups of quantum synthetic matter. A major challenge is the reliability of such schemes in non-Abelian gauge theories where local conservation laws do not commute. Here, we show through exact diagonalization that non-Abelian gauge invariance can be reliably controlled using gauge-protection terms that energetically stabilize the target gauge sector in Hilbert space, suppressing gauge violations due to unitary gauge-breaking errors. We present analytic arguments that predict a volume-independent protection strength $V$, which when sufficiently large leads to the emergence of an \textit{adjusted} gauge theory with the same local gauge symmetry up to least a timescale $\propto \sqrt{V/V_0^3}$. Thereafter, a \textit{renormalized} gauge theory dominates up to a timescale $\propto \exp (V/V_0)/V_0$ with $V_0$ a volume-independent energy factor, similar to the case of faulty Abelian gauge theories. Moreover, we show for certain experimentally relevant errors that single-body protection terms robustly suppress gauge violations up to all accessible evolution times in exact diagonalization, and demonstrate that the adjusted gauge theory emerges in this case as well. These single-body protection terms can be readily implemented with fewer engineering requirements than the ideal gauge theory itself in current ultracold-atom setups and NISQ devices.

    ↳ cond-mat.quant-gascond-mat.str-elhep-lathep-ph+1New J.Phys.(2022)·70 citations
25. 25*

    Spherically symmetric exact vacuum solutions in Einstein-aether theory

    Jacob Oost🇺🇸 · Shinji Mukohyama🇯🇵 · Anzhong Wang🇺🇸

    We study spherically symmetric spacetimes in Einstein-aether theory in three different coordinate systems, the isotropic, Painlevè-Gullstrand, and Schwarzschild coordinates, in which the aether is always comoving, and present both time-dependent and time-independent exact vacuum solutions. In particular, in the isotropic coordinates we find a class of exact static solutions characterized by a single parameter $c_{14}$ in closed forms, which satisfies all the current observational constraints of the theory, and reduces to the Schwarzschild vacuum black hole solution in the decoupling limit ($c_{14}=0$). However, as long as $c_{14}\ne 0$, a marginally trapped throat with a finite non-zero radius always exists, and in one side of it the spacetime is asymptotically flat, while in the other side the spacetime becomes singular within a finite proper distance from the throat, although the geometric area is infinitely large at the singularity. Moreover, the singularity is a strong and spacetime curvature singularity, at which both of the Ricci and Kretschmann scalars become infinitely large.

    ↳ gr-qcastro-ph.GAhep-phhep-thUniverse(2021)·18 citations
26. 26*

    Searching for Dark Matter Particles with Compton Scattering Approach

    Shang Wang🇨🇳 · Changbo Fu🇨🇳 · DeChang Dai🇨🇳 · Hongwei Wang🇨🇳 · Gongtao Fan🇨🇳 · Xiguang Cao🇨🇳 · Yugang Ma🇨🇳

    The dark matter puzzle is one of the most important fundamental physics questions in 21 century. There is no doubt that solving the puzzle will be a new milestone for human beings in the way of deeper understanding the mother nature. Here we propose to use the Shanghai laser electron gamma source (SLEGS) to search for dark matter candidates particles, including dark pseudo scalar particles, dark scalar particles, and dark photons. Our simulations show that electron facilities like SLEGS with some upgrading could be competitive platforms in searching for light dark matter particles with mass under tens of keV.

    ↳ hep-exhep-phCPC(2021)·3 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.