Tree Level Research Articles

Effective field theory of the two Higgs doublet model

We revisit the effective field theory of the two Higgs doublet model at tree level. The introduction of a novel basis in the UV theory allows us to derive matching coefficients in the effective description that resum important contributions from the Higgs vacuum expectation value. The new basis typically provides a significantly better approximation of the full theory prediction than the traditional approach that utilizes the Higgs basis, particularly for alignment away from the decoupling limit.

TaintGuard: Preventing implicit privilege leakage in smart contract based on taint tracking at abstract syntax tree level

Solidity smart contracts play an important role in enabling interactions and collaborations among users in a decentralized blockchain-based community, and their security has received much attention in the industry. One of the most serious security issues faced by Solidity smart contracts is that the use of delegatecall to make cross-contract calls will tamper with contract privilege, which is difficult to detect. To improve the robustness of smart contract privilege control mechanisms at the level of source code, this paper designs and implements a new cross-contract static analysis tool called TaintGuard based on the abstract syntax tree of Solidity code and by combining taint analysis and instrumentation monitoring. TaintGuard uses solc to obtain the abstract syntax tree of the contract source code and then traverses the nodes of the tree to filter call relations that use delegatecall for cross-contract calls. Then, TaintGuard obtains the control flow graph within the target function, determines whether there are problematic paths in the control flow graph that may cause implicit leakage of contract privileges through static taint analysis, and instruments monitoring code in the corresponding position of the program. In this way, the contract status in the runtime stage is monitored to prevent the contract privileges from being tampered with by malicious callers. Finally, TaintGuard is evaluated against existing static analysis tools for Solidity smart contracts. The evaluation results indicate that TaintGuard outperforms other tools in terms of execution efficiency. Also, it can effectively fix the contract code with privilege leaks with a acceptable overhead.

Regional distribution of pericoronary inflammation in post COVID-19 patients - an angio-CT study of epicardial fat attenuation

Abstract Funding Acknowledgements Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): This work was supported by the George Emil Palade University of Medicine, Pharmacy, Science, and Technology of Târgu Mureș, Research Grant number 164/20/10.01.2023. Background Epicardial fat (EF) and pericoronary adipose tissue (PCAT) have been extensively studied in the last decade as markers and promotors of local coronary inflammation. Quantification of EF and PCAT via CCTA, can predict the risk of acute events across various cardiovascular disorders, and has been linked to markers of local or systemic inflammation. Mapping the fat attenuation index (FAI) on routine CCTA can detect coronary artery inflammation at different levels of the coronary tree. Objectives This study aimed to evaluate the regional differences between left and right coronary inflammation in patients who had CCTA examinations for chest pain in the early stages after COVID-19 infection COVID-19 infection, using the AI-powered CaRi-Heart® medical software. Methods In this study, we included 172 patients (mean age: 62.43 ± 11.62 years) with chest pain and low to intermediate clinical likelihood of CAD, who underwent 128-slice CCTA to assess coronary anatomy, atherosclerosis, and FAI – Score determination. The study population was divided into two groups: Group 1 (n = 80) – with COVID-19 infection 2–3 months prior to their CCTA examination, Group 2 (n = 92) – adjusted for age and gender, without COVID-19 infection. For each patient, we recorded and analyzed demographic and clinical characteristics, cardiovascular risk factors, and the onset of signs and symptoms before the CCTA examination. Results The FAI - Score was considerably higher in the non COVID-19 group: LAD (11.87 ± 8.23 vs. 9.12 ± 6.20, p = 0.05), LCX (13.02 ± 6.76 vs. 10.77 ± 6.13, p = 0.05), RCA (15.88 ± 10.36 vs. 14.74 ± 12.24, p = ns), the average FAI - Score (13.23 ± 8.92 vs. 10.34 ± 7.22, p = 0.001). Comparing the FAI - Score between the left and right coronary artery, we found that for the entire study population, the FAI score was significantly higher at the RCA level (15.23 ± 11.97 vs. 11.21 ± 6.98, p = 0.02), and this difference was also maintained in the COVID-19 positive group (14.54 ± 12.17 vs. 9.77 ± 5.94, p = 0.0002), but not in the non-COVID-19 group (14.20 ± 10.78 vs. 12.88 ± 7.41, p = ns). In both groups, the CaRi Heart® Risk (p < 0.0001) and Duke Score (p < 0.0001) were significantly higher for the COVID-negative patients. Conclusions COVID-19 infection is associated with a higher risk of coronary plaque destabilization, as shown by increased inflammation in the PCAT. For the entire study population, the FAI - Score was significantly higher at the RCA level, the difference being driven by the increased RCA inflammation in the post-COVID group. This indicates a potential role of local hemorheological factors in the complex process of inflammation-mediated plaque vulnerabilization.

Electroweak baryogenesis in the three-loop neutrino mass model with dark matter

Baryon asymmetry of the Universe is evaluated in the model originally proposed in Phys. Rev. Lett. 102 (2009) 051805, where Majorana masses of neutrinos are generated via three-loop diagrams composed of additional scalar bosons including the dark matter candidate which is odd under an unbroken $Z_2$ symmetry. In order for the model to include multiple CP-violating phases, we do not impose the softly broken $Z_2$ symmetry imposed in the original model to avoid the flavor-changing neutral current at tree level. Instead, for simplicity, we assume the flavor alignment structure in the Yukawa interactions. We also simply assume the alignment structure in the Higgs potential so that the Higgs couplings coincide with those in the SM at tree level. Under these phenomenological simplifications, the model still contains multiple CP-violating phases. By using destructive interferences among them, it is compatible with the stringent constraint from the electric dipole moment measurements to generate the observed baryon asymmetry along with the scenario of electroweak baryogenesis. We show a benchmark scenario which can explain neutrino mass, dark matter and baryon asymmetry of the universe simultaneously and can satisfy all the other available experimental data. Some phenomenological predictions of the model are also discussed.

The ρ parameter and the CDF-II W-mass anomaly: observations on the role of scalar triplets

The ρ parameter, together with the W and Z masses, acts as Occam’s razor on extensions of the electroweak symmetry-breaking sectors. We apply this to non-doublet Higgs scenarios, by examining the CDF-II claim on the W-boson mass. Suspending any judgment on the CDF claim, we show that in general, if one works at the tree level, theoretical models that predict ρ = 1 at the tree level are inconsistent with the CDF claims at 4–6 standard deviations if one confines oneself to the existing Z-boson mass and the earlier W-boson mass from either the global fit or the ATLAS data. We take some well-motivated scenarios containing one or more scalar SU(2) triplets in addition to the usual doublet and show that both a scenario including a complex scalar triplet and one with a complex as well as a real triplet (the Georgi–Machacek model) can be made consistent with the new data, where a small splitting between the complex and real triplet vacuum expectation values are required in the second scenario. We explore the consequences of this splitting, either at the tree level or via incalculable new physics contribution to W-boson mass and indicate as illustrations its implications in H ± W ∓ Z type interaction vertices.

CP violation in a model with Higgs triplets

We discuss CP-violation in a model with a real and a complex isospin triplet Higgs fields without introducing any symmetries except for the electroweak gauge symmetry. This corresponds to the minimal extension of the Higgs sector with the following properties: (i) providing new source of CP violation, (ii) absence of quark flavor changing neutral currents at tree level, and (iii) enabling the electroweak rho parameter to be unity at tree level in the scenario without imposing any new symmetries. Our model can be regarded as the generalized version of the Georgi-Machacek model, in which the global SU(2)L × SU(2)R symmetry is explicitly broken due to CP-violating terms in the potential. We present analytic formulas for theoretical constraints from perturbative unitarity and vacuum stability as well as contributions to the electron electric dipole moment (EDM) and the neutron EDM from all the Barr-Zee type diagrams. We then examine the parameter space allowed by the constraints mentioned above and also those from the uniqueness of the vacuum, measurements at Tevatron and LHC by using HEPfit to perform a global parameter fit. We find that the decays of the two lightest extra neutral (singly-charged) scalars, H1 and {H}_2left({H}_1^{pm}right) , into hZ (WZ) can be significant at the same time under the constraints, which can serve as direct evidence of CP violation in our model, but not from models with multi-doublet extensions.

Crowd-enabled multiple Pareto-optimal queries for multi-criteria decision-making services

The widespread usage of crowdsourcing systems, which leverage human intelligence to do computer-hard tasks, has created an urgent need to combine crowdsourcing with automated computation while optimizing performance issues, such as monetary cost. The Pareto-optimal query, which is a popular tool for multi-criteria decision-making services, is demanded by many crowdsourcing applications. Traditional researches require explicit attribute values where choices (or objects) are naturally totally ordered. However, it is hard for crowdsourcing workers to provide numerical values, and preferences are partially ordered in many real-life cases. In this paper, we study the problem of multiple Pareto-optimal queries over partial orders by leveraging crowdsourcing to obtain preference relations. The goal is to minimize the number of pairwise comparison questions, thereby reducing the monetary cost. We first introduce the concept of strict dominance where a strictly-dominated non-Pareto-optimal object can be safely pruned without false hits in the final results. We then present a preference tree-based query scheme, where objects in higher levels of this pre-constructed tree are more capable of (strictly-) dominating others. This tree structure enables the crowdsourcing platform to quickly identify non-Pareto-optimal objects and prune strictly-dominated non-Pareto-optimal objects. Extensive experiments demonstrate that the strictly-dominated non-Pareto-optimal objects take up more than 70% of the uniform data set, and the proposed approach effectively reduces the number of comparison questions.

Loop enhancement of direct detection cross section in a fermionic dark matter model

We investigate the effect of one loop quantum corrections on the elastic scattering of dark matter off the nucleon in a fermionic dark matter model. The model introduces two new singlet fermions and a singlet scalar. The fermions communicate with the SM particles through a Higgs portal. It is found that some viable regions in the parameter space respecting the bounds from the observed relic density, the Higgs invisible decay width, and direct detection experiment, will be shrunk significantly when one loop effects are taken into account. The regions already resided below the neutrino floor, partly may come into regions which are testable by the current or future direct detection experiments. In addition, some regions being viable at tree level, may be excluded when quantum corrections are included.

Floristic composition and structure of Eurycoma longifolia habitat in Muka Kuning Nature Tourism Park, Riau Islands, Indonesia

Abstract. Susilowati A, Rachmat HH, Yulita KS, Wijaya K. 2023. Floristic composition and structure of Eurycoma longifolia habitat in Muka Kuning Nature Tourism Park, Riau Islands, Indonesia. Biodiversitas 24: 2836-2842. Eurycoma longifolia Jack, locally called as pasak bumi,is a popular medicinal plant which is known to have properties in curing various diseases. The root of E. longifolia is the organ that has the highest aphrodisiac content so hunting for the roots of E. longifolia destructively causes a significant population decline. Information regarding vegetation community around the habitat of this species is crucial in determining appropriate conservation actions. Muka Kuning Nature Tourism Park (TWA) located in Batam Island, Riau Islands Province is one of the natural habitats of E. longifolia, yet information regarding the state of vegetation in this area has not been obtained. This study aims to determine the floristic composition and structure of vegetation in the habitat of E. longifolia in Muka Kuning Nature Tourism Park focusing on the parameters of Important Value Index (IVI) and biodiversity indices. Vegetation analysis was applied using purposive sampling method based on the presence of E. longifolia individuals. The results showed that the IVI of E. longifolia at the growth stage of seedlings, saplings, poles and trees were 18.1%, 21.9%, 12.14% and 0%, respectively. No individual E. longifolia was found at the tree level which might be attributable to the habitus of this species which is small-sized tree or woody shrub with maximum height of 15 m. The vegetation community at the studied area had Shanon-Wienner diversity index (H') from 2.27 to 3.12 and the Evenness index from 0.88 to 0.98, which is categorized as high. The results of this study imply that the natural habitat of pasak bumi in the TWA Muka Kuning is classified as good and tighter area protection is highly recommended to protect valuable biodiversity in it including E. longifolia.

Remarks on the two-point string amplitudes

The two-point string amplitude at tree level in flat spacetime reproduces the expected expression for free particles. This has been proven by Erbin, Maldacena and Skliros in [JHEP 07 (2019) 139] by two methods. Here, we provide an alternative proof of this result. Our method consists in considering a timelike Liouville direction as a regularization parameter, which suffices to break time translation invariance and, at the same time, to stabilize the residual conformal symmetry in the worldsheet. This allows taking a limit and restoring Poincare symmetry in a controlled way, thus reproducing the correct expression of the two-point amplitude.

Positivity bounds at one-loop level: the Higgs sector

In this paper, we promote the convex cone method of positive bounds from tree level to loop level. This method is general and can be applied to obtain leading s2 positivity bounds on the forward scattering process in the standard model effective field theory. To obtain the loop level bounds, the original tree level bounds are modified by loop corrections, which involve low dimensional coefficients. New positivity bounds being valid at one loop level on the four-Higgs scattering have been provided. We study some specific ultraviolet models to check the validity of the new bounds. In addition, the renormalisation group effect on positivity is explored. We point out that as long as the new bounds are satisfied at the cutoff scale Λ, they will also be satisfied at all scales below Λ.

The S-matrix of 2D type 0B string theory. Part I. Perturbation theory revisited

We study the perturbative S-matrix of closed strings in the two-dimensional type 0B string theory from the worldsheet perspective, by directly integrating correlation functions of mathcal{N} = 1 Liouville theory. The latter is computed numerically using recurrence relations for super-Virasoro conformal blocks. We show that the tree level 3- and 4-point amplitudes are in agreement with the proposed dual matrix quantum mechanics. The non-perturbative aspects of the duality will be analyzed in a companion paper.

Vegetation Analysis of Target Species for Feeding Lesser Yellow Bird of Paradise (Paradisaea minor jobiensis Rothschild, 1897) in the Imbowiari Forest Area of Barawai Village, Yapen Islands District, Papua Province, Indonesia

The research aims to determine the plant species, structure, and composition of the food sources of P. minor jobiensis in the Imbowiari Barawai forest area, Yapen Islands Regency. The method used in this research the method of observation, interviews, documentation, literature, and the checkered line method. Data analysis techniques used are density, dominance, frequency, relative density, relative dominance, relative frequency, important value index, and diversity index. The results of the study found 6 species of plants as food for P. minor jobiensis and spread at the level of seedlings, poles, saplings, and trees namely Elaeocarpus sphaericus, Ficus benjamina, Gnetum gnemon, Syzygium sp., Myristica sp., and Palaquium ambounense

Spectral separability of bark beetle infestation stages: A single-tree time-series analysis using Planet imagery

Bark beetles cause severe damage to European forests leading to impacts on many sectors, from the environmental to the economical. Timely mapping of the different stages of an attack is very important. Remote sensing has been widely used to map bark beetle damage using both airborne and satellite data. Newly available satellite multispectral data with a daily revisit time and high spatial resolution has the potential to monitor an attack in all its phases. This study explores the spectral separability of bark beetle infestation stages using the Planet imagery at individual tree level. Multi-temporal spectral analysis of 78 trees in different stages of a spruce bark beetle attack was carried out. Bands and vegetation indexes derived from 42 multispectral images were compared to eleven field surveys over a time span of approximately four months. The spectral separability analysis was done considering three criteria exploring: 1) the significance of the differences, 2) the magnitude of the differences and 3) the separability in a supervised classification context. The field surveys reported different effects depending on the season of the bark beetle attack - spring vs. summer. Spectral bands and indexes extracted from trees in the healthy and red-stage were significantly different. Trees in the green-attack stage at the end of the summer showed a statistically significant difference from healthy trees. The separability measured with a supervised classifier showed that it is possible to separate healthy, green-attack and red-stage trees with high accuracy values (kappa accuracy above 0.9).

Scattering in black hole backgrounds and higher-spin amplitudes. Part II

We continue to investigate correspondences between, on the one hand, scattering amplitudes for massive higher-spin particles and gravitons in appropriate quantum-to-classical limits, and on the other hand, classical gravitational interactions of spinning black holes according to general relativity. We first construct an ansatz for a gravitational Compton amplitude, at tree level, constrained only by locality, crossing symmetry, unitarity and consistency with the linearized-Kerr 3-point amplitude, to all orders in the black hole’s spin. We then explore the extent to which a unique classical Compton amplitude can be identified by comparing with the results of the classical process of scattering long-wavelength gravitational waves off an exact Kerr black hole, determined by appropriate solutions of the Teukolsky equation. Up to fourth order in spin, we find complete agreement with a previously conjectured exponential form of the tree-level Compton amplitude. At higher orders, we extract tree-level contributions from the Teukolsky amplitude by an analytic continuation from a physical (a/GM < 1) to a particle-like (a/GM > 1) regime. Up to the sixth order in spin, we identify a unique conservative part of the amplitude which is insensitive both to the choice of boundary conditions at the black hole horizon and to branch choices in the analytic continuation. The remainder of the amplitude is determined modulo an overall sign from a branch choice, with the sign flipping under exchanging purely ingoing and purely outgoing boundary conditions at the horizon. Along the way, we make contact with novel applications of massive spinor-helicity variables pertaining to their relation to EFT operators and (spinning) partial amplitudes.

Loop-level double-copy for massive fermions in the fundamental

We find that unitarity cuts and the duality between color and kinematics are sufficient constraints to bootstrap D-dimensional QCD scattering amplitudes starting from three-particle tree-level. Specifically, we calculate tree level amplitudes through six-points, as well as the four-point one-loop correction for massive fermions in the fundamental representation of the gauge group — constructing a color-dual representation of the latter for the first time. To do so we clarify a prescription for functional kinematic ansatze involving fermionic matter. The advantages of color-dual calculation, familiar from particles in the adjoint, also apply here: only a small number of basis topologies must be constrained via physical information of the theory, and algebraic relations propagate this to a full solution. As all the QCD amplitudes we construct here are color-dual, they trivially generate D-dimensional amplitudes in gravitational theories via double-copy construction.

Search for dark matter lines at the Galactic Center with 14 years of Fermi data

Dark matter (DM) in the Milky Way halo may annihilate or decay to photons, producing monochromatic gamma rays. We search for DM-induced spectral lines using 14 years of data from the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope ($\textit{Fermi}$-LAT) between $10\,\mathrm{GeV}$ and $2\,\mathrm{TeV}$ in the inner Milky Way leveraging both the spatial and spectral morphology of an expected signal. We present new constraints as strong as $\langle \sigma v \rangle \lesssim 6\times 10^{-30}\, \mathrm{cm}^3/\mathrm{s}$ for the two-to-two annihilations and $\tau \gtrsim 10^{30}\,\mathrm{s}$ for one-to-two decays, representing leading sensitivity between $10\,\mathrm{GeV}$ and $\sim$$500\,\mathrm{GeV}$. We consider the implications of our line-constraints on the Galactic Center Excess (GCE), which is a previously-observed excess of continuum $\sim$GeV gamma-rays that may be explained by DM annihilation. The Higgs portal and neutralino-like DM scenarios, which have been extensively discussed as possible origins of the GCE, are constrained by our work because of the lack of observed one-loop decays to two photons. More generally, we interpret our null results in a variety of annihilating and decaying DM models, such as neutralinos, gravitinos, and glueballs, showing that in many cases the line search is more powerful than the continuum, despite the continuum annihilation being at tree level.

Constructing EYM amplitudes by inverse soft limit

It is well known that gravity amplitudes in four dimensions can be reconstructed by the inverse soft limit (ISL) method. According to ISL, a tree level n-graviton maximally-helicity-violating (MHV) amplitude is expressed in terms of deformed (n − 1)-graviton amplitudes accompanied by soft graviton factors. On another hand, single- and double-trace tree-level Einstein-Yang-Mills (EYM) MHV amplitudes have been proven to satisfy spanning forest formulas, where each edge in a forest has the same form with a term in soft graviton factor. It is not transparent that the formulas satisfied by EYM amplitudes can be constructed with ISL. In this paper, we construct the single- and double-trace MHV amplitudes in EYM, by the ISL and show that the known formulas can be precisely reproduced. Interesting identities which are based on Schouten identity and characterized by graphs are also introduced.

An energy-efficient command broadcast protocol in dynamic WSNs

In wireless sensor networks (WSNs), a sink must broadcast periodically a command message to a group of nodes or all nodes to control the operation of the network. However, the sparse distribution and limited resources of nodes bring difficulties for efficient broadcasting. In this paper, we propose an energy-efficient command broadcast protocol based on the construction of a spanning tree which includes maximizing the number of leaf nodes, and the allocation of one sharable slot to each tree level. The sharable slot that allocates to tree level will be divided into multiple mini slots, and non-leaf nodes at the same level will compete for broadcasting; in this way, collision can be reduced. Moreover, a node that moves to another level can use the sharable slot allocated to the new level without reallocating the slots. Extensive simulations prove that this approach not only achieves high reliability of message delivery but also energy efficiency.

Automatic Extraction of Forest Inventory Variables at the Tree Level by Using Smartphone Images to Construct a Three-Dimensional Model

This paper focuses on the current urgent demand for the accurate measurement of forest inventory variables in the fields of forestry carbon sink measurement, ecosystem research, and forest resource conservation, and proposes the use of images to construct a three-dimensional measurement model of forest inventory variables, which is a new method to realize the automatic extraction of forest inventory variables. This method obtains sample site information by using high-definition images taken in the forest by a smartphone, which significantly improves the field operation efficiency and simple operation, and effectively alleviates the problems of long field operation times, complicated operations, and expensive equipment used by current methods for obtaining forest inventory variables. We propose to optimize the Eps parameters of the DBSCAN algorithm based on the MVO algorithm for point cloud clustering to obtain single wood point clouds, which improves the accuracy of the model and can effectively solve the problem of large interference from human factors. The scale coefficients of the image and the actual model are obtained by the actual measurement of tree height and diameter at breast height to complete the construction of the three-dimensional measurement model of the stand and are then combined with the AdQSM algorithm to realize the automatic extraction of forest inventory variables, which provides a new interdisciplinary method for the comprehensive extraction of forest inventory variables. The accuracy of the model measured in the experimental sample site of Fraxinus mandshurica Rupr was as follows: the absolute error of tree height measurement ranged from 0.05 to 0.37 m, the highest relative error of measurement was 2.03%, and the average relative error was 1.53%; for the absolute error of diameter at breast height, measurement ranged from 0.007 to 0.057 m, the highest relative error of measurement was 7.358%, and the average relative error was 3.616%. The method proposed in this study can be directly applied to the process of acquiring and visualizing the variables of forest inventory in the field of ecological research, which has good flexibility and can meet individual research needs.