ShantanuT01/DACTYL-Pretraining huggingface dataset:
We investigate the phenomenology of a model based on the $SU(3)_c\times SU(3)_L\times U(1)_X$ gauge theory, the so-called 331 model. In particular, we focus on the Higgs sector of the model which is composed of three $SU(3)_L$ triplet Higgs fields, and this corresponds to the minimal form to realize phenomenologically acceptable scenario. After the spontaneous symmetry breaking $SU(3)_L\times U(1)_X\to SU(2)_L\times U(1)_Y$, our Higgs sector effectively becomes that with two $SU(2)_L$ doublet scalar fields, in which the first and the second generation quarks couple to the different Higgs doublet from that couples to the third generation quarks. This structure causes the flavour changing neutral current mediated by Higgs bosons at the tree level. By taking an alignment limit of the mass matrix for the CP-even Higgs bosons, which is naturally realized in the case with the breaking scale of $SU(3)_L\times U(1)_X$ to be much larger than that of $SU(2)_L\times U(1)_Y$, we can avoid current constraints from flavour experiments such as the $B^0$-$\bar{B}^0$ mixing even for the Higgs bosons masses being ${\cal O}(100)$ GeV. In this allowed parameter space, we clarify that a characteristic deviation in quark Yukawa couplings of the standard model-like Higgs boson is predicted, which has a different pattern from that seen in two Higgs doublet models with a softly-broken $Z_2$ symmetry. We also find that the flavour violating decay modes of the extra Higgs boson, e.g., $H/A \to tc$ and $H^\pm \to ts$ can be dominant, and they yield the important signature to distinguish our model from the two Higgs doublet models.
The Cold Spot (CS) is a clear feature in the Cosmic Microwave Background (CMB); it could be of primordial origin, or caused by a intervening structure along the line of sight. We identified a large projected underdensity in the recently constructed WISE-2MASS all-sky infrared galaxy catalogue aligned with the Cold Spot direction at $(l,b)\approx(209^\circ,-57^\circ)$. It has an angular size of tens of degrees, and shows a $\sim20\%$ galaxy underdensity in the center. Moreover, we find another large underdensity in the projected WISE-2MASS galaxy map at $(l,b)\approx(101^\circ,46^\circ)$ (hereafter Draco Supervoid), also aligned with a CMB decrement, although less significant than that of the CS direction. Motivated by these findings, we develop spherically symmetric Lemaitre-Tolman-Bondi (LTB) compensated void models to explain the observed CMB decrements with these two underdensities, or "supervoids". Within our perturbative treatment of the LTB voids, we find that the Integrated Sachs-Wolfe and Riess-Sciama effects due to the Draco Supervoid can account for the CMB decrement observed in the same direction. On the contrary, the extremely deep CMB decrement in the CS direction is more difficult to explain by the presence of the CS supervoid only. Nevertheless, the probability of a random alignment between the CS and the corresponding supervoid is disfavored, and thus its contribution as a secondary anisotropy cannot be neglected. We comment on how the approximations used in this paper, in particular the assumption of spherical symmetry, could change quantitatively our conclusions and might provide a better explanation for the CMB CS.
We observed a strong modulation in the current-voltage characteristics of SrRuO$_3$/Nb:SrTiO$_3$ Schottky junctions by Mn substitution in SrRuO$_3$, which induces a metal-insulator transition in bulk. The temperature dependence of the junction ideality factor indicates an increased spatial inhomogeneity of the interface potential with substitution. Furthermore, negative differential resistance was observed at low temperatures, indicating the formation of a resonant state by Mn substitution. By spatially varying the position of the Mn dopants across the interface with single unit cell control, we can isolate the origin of this resonant state to the interface SrRuO$_3$ layer. These results demonstrate a conceptually different approach to controlling interface states by utilizing the highly sensitive response of conducting perovskites to impurities.
Bursts of millisecond duration were recently discovered in the 1 GHz band. There is a strong evidence that they come from $\sim 1 $ Gpc distances, which implies extraordinary high brightness temperature. I propose that these bursts could be attributed to synchrotron maser emission from relativistic, magnetized shocks. At the onset of the magnetar flare, a strongly magnetized pulse is formed, which propagates away through the relativistic magnetar wind and eventually reaches the nebula inflated by the wind within the surrounding medium. I show that the observed radio bursts could be generated at shocks formed via the interaction of the magnetic pulse with the plasma within the nebula. The model predicts strong millisecond bursts in the TeV band, which could be observed even from distant galaxies.
Alternative gravitations of Milgrom (MOND), Moffat (MOG), and CDM scenarios all simulate rotation curves of spirals with reasonable details. They display significant disparities however in predicting the stellar mass-to-light ($M_*/L$) ratios of the galaxies. We maintain this feature could serve as a distinguishing factor between different alternative theories. We analyze the rotation curves of 46 low- and high-surface brightness galaxies and compare the resulting $M_*/L$s with the predictions of the Stellar Population Synthesis (SPS) scheme. The color-$M_*/L$ correlation obtained for MOND is consistent with predictions of SPS models. MOG does not show this consistency, and the $M_*/L$s of CDM model shows large dispersions. Furthermore, $M_*/L$ ratios of MOND with Bekenstein interpolating function favor Kroupa's initial mass function (IMF) of the SPS scheme, while those of MOND with standard and simple interpolating functions are consistent with Salpeter's IMF. Here is another indication to differentiate between different IMFs that are used in SPS context.
NLO QCD fits using the DGLAP formalism have been made to the high precision ZEUS $e^+p$ reduced cross-section data and to fixed target structure function data, in order to detrmine parton distribution functions and the value of $\alpha_s(M^2_Z)$, taking full account of correlated systematic errors. Preliminary results are reported.
The momentum and isospin dependence of the single-particle potential for the in-medium nucleon are the key quantities in the Relativistic Brueckner-Hartree-Fock (RBHF) theory. It depends on how to extract the scalar and the vector components of the single-particle potential inside nuclear matter. In contrast to the RBHF calculations in the Dirac space with the positive-energy states (PESs) only, the single-particle potential can be determined in a unique way by the RBHF theory together with the negative-energy states (NESs), i.e., the RBHF theory in the full Dirac space. The saturation properties of symmetric and asymmetric nuclear matter in the full Dirac space are systematically investigated based on the realistic Bonn nucleon-nucleon potentials. In order to further specify the importance of the calculations in the full Dirac space, the neutron star properties are investigated. The direct URCA process in neutron star cooling will happen at density $\rho_{\rm{DURCA}}=0.43,~0.48,~0.52$ fm$^{-3}$ with the proton fractions $Y_{p,\rm{DURCA}}=0.13$. The radii of a $1.4M_\odot$ neutron star are predicated as $R_{1.4M_\odot}=11.97,~12.13,~12.27$ km, and their tidal deformabilities are $\Lambda_{1.4M_\odot}=376,~405,~433$ for potential Bonn A, B, C. Comparing with the results obtained in the Dirac space with PESs only, full-Dirac-space RBHF calculation predicts the softest symmetry energy which would be more favored by the gravitational waves (GW) detection from GW170817. Furthermore, the results from full-Dirac-space RBHF theory are consistent with the recent astronomical observations of massive neutron stars and simultaneous mass-radius measurement.
We show that a Kondo-type model with an orbital degeneracy has a new non-Fermi-liquid fixed point. Near the fixed point the spin degrees of freedom are completely quenched, and the residual charge degrees of freedom lead to the multi-channel Kondo effect. Anomalous behavior appears in electric and thermal properties, but the magnetic susceptibility should show the local Fermi-liquid behavior. The non-Fermi-liquid fixed point becomes unstable against perturbations breaking the particle-hole symmetry. We derive these results using the third-order scaling for a spherically symmetric model with a fictitious spin. In contrast to the Coqblin-Schrieffer model, the present model respects different time-reversal properties of multipole operators.
A non-covariant but approximately relativistic two-body wave equation (Breit equation) describing the quantum mechanics of two fermions interacting with one another through a potential containing scalar, pseudoscalar and vector parts is presented. After expressing the sixteen component two-body wavefunction in terms of a radial and an angular function by means of the multipole expansion, the initial equation can be reduced into a set of sixteen radial equations which, in turn, can be classified in accordance to the parity and the state of the wavefunctions involved. The adequacy of the reduced equations in describing real problems is discussed by applying the theory to QCD problems and the calculation of the energies of bound states of quark-antiquark systems is performed to order $\alpha^4$. We show that bound states of heavy quarks can be described adequately by the Breit equation for a funnel interaction between the particles
Although the gamma-ray emission in blazars dominates the power output, there are crucial informations carried by the X-rays. Indeed, their paucity, together with the short variability timescales observed both at X and gamma-ray energies constrains the location, along the jet, of the active region responsible for most of the emission. Furthermore, the knowledge of the X-ray flux and spectrum helps in defining the overall spectral energy distribution (SED) of blazars, allowing to discriminate between models.
The color distributions of globular clusters (GCs) in individual early-type galaxies show great diversity in their morphology. Based on the conventional "linear" relationship between the colors and metallicities of GCs, the GC metallicity distributions inferred from colors and in turn their formation histories, should be as diverse as they appear. In contrast, here we show that an alternative scenario rooted in the "nonlinear" nature of the metallicity-to-color transformation points to a simpler and more coherent picture. Our simulations of the color distributions for $\sim$80 GC systems in early-type galaxies from the ACS Virgo and Fornax Cluster Surveys suggest that the majority ($\sim$70$\%$) of early-type galaxies have old ($\sim$13 Gyr) and coeval GCs. Their variety in the color distribution morphology stems mainly from one parameter, the mean metallicity of a GC system. Furthermore, the color distributions of the remaining ($\sim$30$\%$) GC systems are also explained by the nonlinearity scenario, assuming additional young or intermediate-age GCs with a number fraction of $\sim$20$\%$ of underlying old GCs. Our results reinforce the nonlinearity explanation for the GC color bimodality and provide a new perspective on early-type galaxy formation in the cluster environment, such as the Virgo and Fornax galaxy clusters.
Measurement-device-independent quantum key distribution (MDI-QKD) is immune to all security loopholes on detection. Previous experiments on MDI-QKD required spatially separated signal lasers and complicated stabilization systems. In this paper, we perform a proof-of-principle experimental demonstration of plug-and-play MDI-QKD over an asymmetric channel setting with a single signal laser, in which the whole system is automatically stabilized in spectrum, polarization, arrival time and phase reference. Both the signal laser and the single-photon detectors are in the possession of a common server. A passive timing calibration technique is applied to ensure the precise and stable overlap of signal pulses. The results pave the way for the realization of a quantum network, in which the users only need the encoding devices.
We consider the critical dissipative SQG equation in bounded domains, with the square root of the Dirichlet Laplacian dissipation. We prove global a priori interior $C^{\alpha}$ and Lipschitz bounds for large data.
In this review we present the theoretical background for treating General Relativity as an effective field theory and focus on the concrete results of such a treatment. As a result we present the calculations of the low-energy leading gravitational corrections to the Newtonian potential between two sources.
The aim of this work is to develop a framework for realising quantum network algorithms with the use of prior knowledge about the structure of the network. We seek to obtain computational methods that allows us to locally determine network properties in a quantum superposition and drive the walk behaviour accordingly. In particular, we consider a network that consists of different types of edges, such that the transitions between nodes result in extra edge-dependent phase shift. We combine amplitude amplification and phase estimation to develop an algorithm for exploring such networks. In the layered neural network inspired case we obtain linear increase of the search complexity with exponential growth of the nodes number. We show that in consequence one is able to perform quantum search algorithms with exponential speed-up compared to quantum search that neglects the extra phase shifts.
The potential of the $B$ meson and the pseudoscalar meson is constructed up to the next-to-leading order Lagrangian, and then the $B \bar{K}$ and $B_s \pi$ interaction is studied in the unitary coupled-channel approximation, and a resonant state with a mass about $5568MeV$ and $J^P=0^+$ is generated dynamically, which can be associated with the $X(5568)$ state announced by D0 Collaboration recently. The mass and the decay width of this resonant state depend on the regularization scale in the dimensional regularization scheme, or the maximum momentum in the momentum cutoff regularization scheme. The scattering amplitude of the vector $B$ meson and the pseudoscalar meson is calculated, and an axial-vector state with a mass near $5620MeV$ and $J^P=1^+$ is produced. Moreover, their partners in the charm sector are also discussed.
Given a smooth projective variety V of dimension n, one may say that V has motivic dimension less than d+1 if the cohomology of V comes from varieties of dimensions less than d+1 in some geometric way. In this paper, we show that a smooth complete interesection of k quadrics has a motivic dimension less than k.
Quantum effects such as the environment assisted quantum transport (ENAQT) displayed in photosynthetic Fenna-Mathews-Olson (FMO) complex has been simulated on analog quantum simulators. Digital quantum simulations offer greater universality and flexibility over analog simulations. However, digital quantum simulations of open quantum systems face a theoretical challenge; one does not know the solutions of the continuous time master equation for developing quantum gate operators. We give a theoretical framework for digital quantum simulation of ENAQT by introducing new quantum evolution operators. We develop the dynamical equation for the operators and prove that it is an analytical solution of the master equation. As an example, using the dynamical equations, we simulate the FMO complex in the digital setting, reproducing theoretical and experimental evidence of the dynamics. The framework gives an optimal method for {quantum circuit} implementation, giving a log reduction in complexity over known methods. The generic framework can be extrapolated to study other open quantum systems.
A primordial magnetic field (PMF) present before recombination can leave specific signatures on the cosmic microwave background (CMB) fluctuations. Of particular importance is its contribution to the B-mode polarization power spectrum. Indeed, vortical modes sourced by the PMF can dominate the B-mode power spectrum on small scales, as they survive damping up to a small fraction of the Silk length. Therefore, measurements of the B-mode polarization at high-$\ell$ , such as the one recently performed by the South Pole Telescope (SPT), have the potential to provide stringent constraints on the PMF. We use the publicly released SPT B-mode polarization spectrum, along with the temperature and polarization data from the Planck satellite, to derive constraints on the magnitude, the spectral index and the energy scale at which the PMF was generated. We find that, while Planck data constrains the magnetic amplitude to $B_{1 \, \text{Mpc}} < 3.3$ nG at 95\% confidence level (CL), the SPT measurement improves the constraint to $B_{1 \, \text{Mpc}} < 1.5$ nG. The magnetic spectral index, $n_B$, and the time of the generation of the PMF are unconstrained. For a nearly scale-invariant PMF, predicted by simplest inflationary magnetogenesis models, the bound from Planck+SPT is $B_{1 \, \text{Mpc}} < 1.2$ nG at 95% CL. For PMF with $n_B=2$, expected for fields generated in post-inflationary phase transitions, the 95% CL bound is $B_{1 \, \text{Mpc}} < 0.002$ nG, corresponding to the magnetic fraction of the radiation density $\Omega_{B\gamma} < 10^{-3}$ or the effective field $B_{\rm eff} < 100$ nG. The patches for the Boltzmann code CAMB and the Markov Chain Monte Carlo engine CosmoMC, incorporating the PMF effects on CMB, are made publicly available.
We report on the dielectric properties of epitaxial [001] and [100]-textured thin films of antiferromagnetic orthorhombic YMnO3 and their variation under compressive epitaxial strain. It is found that weakly strained YMnO3 films are ferroelectric with a polarization along c-axis switchable by 90 degrees by an external magnetic field. When reducing film thickness and increasing epitaxial strain, the ferroelectric order is progressively suppressed. Analysis of structural, dielectric and magnetic data indicates that suppression of ferroelectricity when reducing thickness is accompanied by an enlarged ratio a/b of the in-plane cell parameters of the orthorhombic structure and the appearance of a net magnetization. All results can be well described by considering the multiferroic phase diagram of orthorhombic manganites.
A method parametrizing all inelastic final state interactions (FSI) in $B\to PP$ decays is presented ($P$ - pseudoscalar meson). The method explicitly shows how rescattering leads to the replacement of the short-distance amplitudes with the effective quark diagram amplitudes, and how it affects the extraction of the unitarity triangle angle $\gamma $ from the data. It is furthermore pointed out that the size of FSI effects cannot be determined from $B^0_d \to K^+ K^-$ decays in a satisfactory way. The case of SU(3)-violating FSI is also discussed. When fits to the branching ratios of all $B \to PP$ decays are performed with all inelastic FSI included, the extracted value of $ \gamma $ is shifted down by some $20^o-30^o$ when compared to the no-FSI analyses, and becomes consistent with the Standard Model value of $ 65^o \pm 7^o$.
In this paper an extensive survey of the star forming complex Sh2-252 has been undertaken with an aim to explore its hidden young stellar population as well as to understand the structure and star formation history. This complex is composed of five embedded clusters associated with the sub-regions A, C, E, NGC 2175s and Teu 136. Using 2MASS-NIR and Spitzer-IRAC, MIPS photometry we identified 577 young stellar objects (YSOs), of which, 163 are Class I, 400 are Class II and 14 are transition disk YSOs. Spatial distribution of the candidate YSOs shows that they are mostly clustered around the sub-regions in the western half of the complex, suggesting enhanced star formation activity towards its west. Using the spectral energy distribution and optical colour-magnitude diagram based age analyses, we derived probable evolutionary status of the sub-regions of Sh2-252. Our analysis shows that the region A is the youngest (~ 0.5 Myr), the regions B, C and E are of similar evolutionary stage (~ 1-2 Myr) and the clusters NGC 2175s and Teu 136 are slightly evolved (~ 2-3 Myr). Morphology of the region in the 1.1 mm map shows a semi-circular shaped molecular shell composed of several clumps and YSOs bordering the western ionization front of Sh2-252. Our analyses suggest that next generation star formation is currently under way along this border and that possibly fragmentation of the matter collected during the expansion of the HII region as one of the major processes responsible for such stars. We observed the densest concentration of YSOs (mostly Class I, ~ 0.5 Myr) at the western outskirts of the complex, within a molecular clump associated with water and methanol masers and we suggest that it is indeed a site of cluster formation at a very early evolutionary stage, sandwiched between the two relatively evolved CHII regions A and B.
Controllable synthesis of defect-free graphene is crucial for applications since the properties of graphene are highly sensitive to any deviations from the crystalline lattice. We focus here on the emerging use of liquid Cu catalysts, which has high potential for fast and efficient industrial-scale production of high-quality graphene. The interface between graphene and liquid Cu is studied using force field and ab initio molecular dynamics, revealing a complete or partial embedding of finite-sized flakes. By analyzing flakes of different sizes we find that the size-dependence of the embedding can be rationalized based on the energy cost of embedding versus bending the graphene flake. The embedding itself is driven by the formation of covalent bonds between the under-coordinated edge C atoms and the liquid Cu surface, which is accompanied by a significant charge transfer. In contrast, the central flake atoms are located around or slightly above 3 {\AA} from the liquid Cu surface and exhibit weak vdW-bonding and much lower charge transfer. The structural and electronic properties of the embedded state revealed in our work provides the atomic-scale information needed to develop effective models to explain the special growth observed in experiments where various interesting phenomena such as flake self-assembly and rotational alignment, high growth speeds and low defect densities in the final graphene product have been observed.
We establish asymptotic formulae for various correlations involving general divisor functions $d_k(n)$ and partial divisor functions $d_l(n,A)=\sum_{q|n:q\leq n^A}d_{l-1}(q)$, where $A\in[0,1]$ is a parameter and $k,l\in\mathbb{N}$ are fixed. Our results relate the parameter $A$ to the lengths of arithmetic progressions in which $d_k(n)$ is uniformly distributed. As applications to additive divisor sums, we establish new lower bounds and a new equivalent condition for the conjectured asymptotic. We also prove a Tauberian theorem for general additive divisor sums.
The two-dimensional ($2$D) spin-$S=1$ $XY$ model was investigated numerically as a realization of the $(2+1)$D superfluid-Mott-insulator (SF-MI) transition. The interaction parameters are extended so as to suppress corrections to finite-size scaling. Thereby, the external field of a unit flux quantum ($\Phi=2\pi$) is applied to the 2D cluster by incorporating the phase factor $e^{i\phi_{ij}}$ ($\phi_{ij}$: gauge angle between the $i$ and $j$ sites) into the hopping amplitudes. Taking the advantage in that the exact-diagonalization method allows us to treat such a complex-valued matrix element, we evaluated the excess energy cost $\Delta E(2\pi)$ due to the magnetic flux $\Phi=2\pi$ explicitly in the SF ($XY$) phase. As a result, we found that the amplitude ratio $\rho_s / \Delta E(2\pi)$ ($\rho_s$: spin stiffness) makes sense in proximity to the critical point, exhibiting a notable plateau in the SF-phase side. The plateau height is estimated, and compared to the related studies.