Composite dark matter and Higgs Wu, Yongcheng; Ma, Teng; Zhang, Bin ...
The journal of high energy physics,
11/2017, Letnik:
2017, Številka:
11
Journal Article
Recenzirano
Odprti dostop
A
bstract
We investigate the possibility that Dark Matter arises as a composite state of a fundamental confining dynamics, together with the Higgs boson. We focus on the minimal SU(4)×SU(4)/SU(4) ...model which has both a Dark Matter and a Higgs candidates arising as pseudo-Nambu-Goldstone bosons. At the same time, a simple underlying gauge-fermion theory can be defined providing an existence proof of, and useful constraints on, the effective field theory description. We focus on the parameter space where the Dark Matter candidate is mostly a gauge singlet. We present a complete calculation of its relic abundance and find preferred masses between 500 GeV to a few TeV. Direct Dark Matter detection already probes part of the parameter space, ruling out masses above 1 TeV, while Indirect Detection is relevant only if non-thermal production is assumed. The prospects for detection of the odd composite scalars at the LHC are also established.
A
bstract
We describe the on-shell method to derive the Renormalization Group (RG) evolution of Wilson coefficients of high dimensional operators at one loop, which is a necessary part in the ...on-shell construction of the Standard Model Effective Field Theory (SMEFT), and exceptionally efficient based on the amplitude basis in hand. The UV divergence is obtained by firstly calculating the coefficients of scalar bubble integrals by unitary cuts, then subtracting the IR divergence in the massless bubbles, which can be easily read from the collinear factors we obtained for the Standard Model fields. Examples of deriving the anomalous dimensions at dimension six are presented in a pedagogical manner. We also give the results of contributions from the dimension-8
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Chronic exposure to geogenic contaminated groundwaters (GCGs) has caused serious health problems among billions of people worldwide. The hydrogeological features, main sources of geogenic hazardous ...substances, dominant hydrogeochemical processes and key factors controlling the occurrence of high arsenic (As ≥ 10 μg/L), high fluoride (F ≥ 1 mg/L), and high iodine (I ≥ 100 μg/L) groundwater are discussed in this review. Although the global and/or regional occurrence, and the environmental and geochemical behaviors of groundwater As, F and I have been well documented in the past three decades, there is still a lack of holistic theoretical analysis to demonstrate the hydrogeological patterns of their (co)occurrence. We here propose four basic genetic types of GCGs by summarizing the characteristics of the distribution and major hydrogeochemical processes: leaching-enrichment type, burial-dissolution type, compaction-release type, and evaporation-concentration type. The complex genetic mechanisms of GCGs are thus integrated into a new theoretical framework to improve our understanding of their genesis and our capability of predicting their spatial and temporal distribution. Moreover, new paradigms of interdisciplinary convergent research are required to find best solutions to ensure the sustainable safe supply of groundwater resources and the well-being of the groundwater-dependent ecosystems and the human society.
PurposeThe role of corporate social responsibility (CSR) fulfillment is critical when building resilience of project-based organizations (PBOs). However, fulfilling CSR to build a highly resilient ...PBO remains a black box problem. This study explores the different CSR combinations that enhance PBO resilience.Design/methodology/approachThis study defines CSR in terms of shareholder, employee, and social CSR, and analyzes corporate characteristics in terms of corporate scale and nature. Data are collected from Hexun.com and the China Stock Market and Accounting Research Database (CSMAR). The qualitative comparative analysis (QCA) method is used to analyze 48 listed construction and engineering companies from China to explore the CSR configurations for PBOs in enhancing organizational resilience.FindingsA large firm size is a necessary condition for high organizational resilience. We find six paths to build high and non-high resilience in PBOs, and the driving mechanisms of high and non-high resilience exhibit an asymmetric relationship.Research limitations/implicationsThis study cracks the black box of CSR fulfillment and PBO resilience. It reveals the CSR configurations that enhance or inhibit the resilience of PBOs. It also provides scientific basis for PBOs in their fulfillment of CSR in response to crises, and the enhancement of organizational resilience. Future research can be expanded to other industries, as the study sample is only limited to civil engineering construction companies. Since this study uses cross-sectional data, time series can be introduced in the future to further explore the relationship between CSR and organizational resilience.Practical implicationsThis study provides targeted suggestions that can help decision-makers of construction companies to determine how they can fulfill CSR to enhance organizational resilience. At the same time, it can provide intellectual support for PBOs to cope with systemic crises and promote the fulfillment of CSR.Originality/valueIn terms of theoretical value, on the one hand, this study verifies the relationship between CSR fulfillment and PBO resilience, revealing its mechanism of action and multiple paths; on the other hand, it provides a new way of thinking for management research methods and enriches the theoretical study of organizational resilience.
Human cerebral organoids derived from induced pluripotent stem cells (iPSCs) provide novel tools for recapitulating the cytoarchitecture of human brain and for studying biological mechanisms of ...neurological disorders. However, the heterotypic interactions of neurovascular units, composed of neurons, pericytes, astrocytes, and brain microvascular endothelial cells, in brain-like tissues are less investigated. The objective of this study is to investigate the impacts of neural spheroids and vascular spheroids interactions on the regional brain-like tissue patterning in cortical spheroids derived from human iPSCs. Hybrid neurovascular spheroids were constructed by fusion of human iPSC-derived cortical neural progenitor cell (iNPC) spheroids, endothelial cell (iEC) spheroids, and the supporting human mesenchymal stem cells (MSCs). Single hybrid spheroids were constructed at different iNPC: iEC: MSC ratios of 4:2:0, 3:2:1 2:2:2, and 1:2:3 in low-attachment 96-well plates. The incorporation of MSCs upregulated the secretion levels of cytokines VEGF-A, PGE2, and TGF-β1 in hybrid spheroid system. In addition, tri-cultured spheroids had high levels of TBR1 (deep cortical layer VI) and Nkx2.1 (ventral cells), and matrix remodeling genes, MMP2 and MMP3, as well as Notch-1, indicating the crucial role of matrix remodeling and cell-cell communications on cortical spheroid and organoid patterning. Moreover, tri-culture system elevated blood-brain barrier gene expression (e.g., GLUT-1), CD31, and tight junction protein ZO1 expression. Treatment with AMD3100, a CXCR4 antagonist, showed the immobilization of MSCs during spheroid fusion, indicating a CXCR4-dependent manner of hMSC migration and homing. This forebrain-like model has potential applications in understanding heterotypic cell-cell interactions and novel drug screening in diseased human brain.
Cyanines have been widely used as the photosensitizers (PSs) in the biomedical field, but controlling their molecular aggregates in nanoparticles (NPs) remains a major challenge. Moreover, the impact ...of aggregate behaviors of cyanines on the photosensitization is still unclear. Herein, the first anionic cyanine PSs based on a tricyanofuran end group have been designed by achieving supramolecular J‐type aggregates in NPs via counterion engineering. Our results indicate that J‐type aggregates in NPs can not only bring significantly red‐shifted emission, negatively charged surface, and high photostability, but also enable a significant 5‐fold increase in singlet oxygen generation efficiency compared to that in the nonaggregate state, providing strong experimental evidence for the superiority of J‐aggregates in enhancing photosensitization. Thus, combined with the mitochondria‐targeting ability, the J‐type aggregate NPs show remarkable in vivo antitumor phototheranostic efficacy, making them have a potential for clinical use.
For the first time, anionic cyanines are designed as the phototherapy agents by controlling their aggregates through counterion engineering. The resulting J‐type aggregate nanoparticles show NIR emission, high photostability, negatively charge surface, mitochondria‐targeting ability, and significantly enhanced singlet oxygen generation efficiency, leading to efficient antitumor phototherapy efficacy.
Optical harmonic generation occurs when high intensity light (>10
W m
) interacts with a nonlinear material. Electrical control of the nonlinear optical response enables applications such as ...gate-tunable switches and frequency converters. Graphene displays exceptionally strong light-matter interaction and electrically and broadband tunable third-order nonlinear susceptibility. Here, we show that the third-harmonic generation efficiency in graphene can be increased by almost two orders of magnitude by controlling the Fermi energy and the incident photon energy. This enhancement is due to logarithmic resonances in the imaginary part of the nonlinear conductivity arising from resonant multiphoton transitions. Thanks to the linear dispersion of the massless Dirac fermions, gate controllable third-harmonic enhancement can be achieved over an ultrabroad bandwidth, paving the way for electrically tunable broadband frequency converters for applications in optical communications and signal processing.
We introduce the
-adic weighted central Campanato spaces
and characterize
by the boundedness of the commutators of
-adic
-dimensional Hardy operators on
-adic weighted central Morrey spaces for
. In ...particular, the characterizations of
-adic weighted central
spaces are also obtained.
Stealth decaying spin-1 dark matter Delaunay, Cédric; Ma, Teng; Soreq, Yotam
The journal of high energy physics,
02/2021, Letnik:
2021, Številka:
2
Journal Article
Recenzirano
Odprti dostop
A
bstract
We consider models of decaying spin-1 dark matter whose dominant coupling to the standard model sector is through a dark-Higgs Yukawa portal connecting a TeV-scale vector-like lepton to the ...standard model (right-handed) electron. Below the electron-positron threshold, dark matter has very slow, loop-suppressed decays to photons and (electron) neutrinos, and is stable on cosmological time-scale for sufficiently small gauge coupling values. Its relic abundance is set by in-equilibrium dark lepton decays, through the freeze-in mechanism. We show that this model accommodates the observed dark matter abundance for natural values of its parameters and a dark matter mass in the ∼ 5 keV to 1 MeV range, while evading constraints from direct detection, indirect detection, stellar cooling and cosmology. We also consider the possibility of a nonzero gauge kinetic mixing with the standard model hypercharge field, which is found to yield a mild impact on the model’s phenomenology.
By adopting the autoregressive-distributed lag error correction model, we examine both the short- and long-term impacts of feed-in policies on renewable energy deployment. The estimation results show ...that the feed-in premium scheme achieved its objective of encouraging the market integration of wind energy but discouraged and retarded investment in solar power technologies. Compared to the market mechanism, fixed price feed-in policy creates greater investment security for solar power projects.
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