848 research outputs found

    UV-finite scalar field theory with unitarity

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    In this paper we show how to define the UV completion of a scalar field theory such that it is both UV-finite and perturbatively unitary. In the UV completed theory, the propagator is an infinite sum of ordinary propagators. To eliminate the UV divergences, we choose the coefficients and masses in the propagator to satisfy certain algebraic relations, and define the infinite sums involved in Feynman diagram calculation by analytic continuation. Unitarity can be proved relatively easily by Cutkosky's rules. The theory is equivalent to infinitely many particles with specific masses and interactions. We take the Ï•4\phi^4 theory as an example and demonstrate our idea through explicit Feynman diagram computation.Comment: 14 pages, references adde

    Three-body molecules DˉDˉ∗Σc\bar{D}\bar{D}^{\ast}\Sigma_{c}- understanding the nature of TccT_{cc}, Pc(4312)P_{c}(4312), Pc(4440)P_{c}(4440) and Pc(4457)P_{c}(4457)

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    The nature of the three pentaquark states, Pc(4312)P_{c}(4312), Pc(4440)P_{c}(4440) and Pc(4457)P_{c}(4457), discovered by the LHCb Collaboration in 2019, is still under debate, although the Dˉ(∗)Σc\bar{D}^{(\ast)}\Sigma_{c} molecular interpretation seems to be the most popular. In this work, by adding a Dˉ\bar{D} meson into the Dˉ∗Σc\bar{D}^{\ast}\Sigma_{c} pair, we investigate the mass and decay width of the three-body molecules DˉDˉ∗Σc\bar{D}\bar{D}^{\ast}\Sigma_{c} and explore the correlation between the existence of the DˉDˉ∗Σc\bar{D}\bar{D}^{\ast}\Sigma_{c} molecules with the existence of Dˉ(∗)Σc\bar{D}^{(\ast)}\Sigma_{c} and Dˉ∗Dˉ\bar{D}^{\ast}\bar{D} two-body molecules. The latter can be identified with the doubly charmed tetraquark state TccT_{cc} recently discovered by the LHCb Collaboration. Based on the molecular nature of Pc(4312)P_{c}(4312), Pc(4440)P_{c}(4440), Pc(4457)P_{c}(4457), and TccT_{cc}, our results indicate that there exist two three-body bound states of DˉDˉ∗Σc\bar{D}\bar{D}^{\ast}\Sigma_{c} with I(JP)=1(1/2+)I(J^{P})=1(1/2^{+}) and I(JP)=1(3/2+)I(J^{P})=1(3/2^{+}), and binding energies 37.2437.24 MeV and 29.6329.63 MeV below the DˉDˉ∗Σc\bar{D}\bar{D}^{\ast}\Sigma_{c} mass threshold. In addition, we find that the mass splitting of these two three-body molecules are correlated to the mass splitting of Pc(4440)P_{c}(4440) and Pc(4457)P_{c}(4457), which offers a non-trivial way to reveal the molecular nature of these states. The partial widths of two DˉDˉ∗Σc\bar{D}\bar{D}^{\ast}\Sigma_{c} molecules decaying into J/ψpDˉJ/\psi p \bar{D} and J/ψpDˉ∗J/\psi p \bar{D}^{\ast} are found to be several MeV. We recommend the experimental searches for the DˉDˉ∗Σc\bar{D}\bar{D}^{\ast}\Sigma_{c} molecules in the J/ψpDˉJ/\psi p \bar{D} and J/ψpDˉ∗J/\psi p \bar{D}^{\ast} invariant mass distributions

    Automatic Blastomere Recognition from a Single Embryo Image

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    The number of blastomeres of human day 3 embryos is one of the most important criteria for evaluating embryo viability. However, due to the transparency and overlap of blastomeres, it is a challenge to recognize blastomeres automatically using a single embryo image. This study proposes an approach based on least square curve fitting (LSCF) for automatic blastomere recognition from a single image. First, combining edge detection, deletion of multiple connected points, and dilation and erosion, an effective preprocessing method was designed to obtain part of blastomere edges that were singly connected. Next, an automatic recognition method for blastomeres was proposed using least square circle fitting. This algorithm was tested on 381 embryo microscopic images obtained from the eight-cell period, and the results were compared with those provided by experts. Embryos were recognized with a 0 error rate occupancy of 21.59%, and the ratio of embryos in which the false recognition number was less than or equal to 2 was 83.16%. This experiment demonstrated that our method could efficiently and rapidly recognize the number of blastomeres from a single embryo image without the need to reconstruct the three-dimensional model of the blastomeres first; this method is simple and efficient

    The neural correlates of value hierarchies: a prospective typology based on personal value profiles of emerging adults

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    IntroductionValue hierarchies, as motivational goals anchored in the self-schema, may be correlated with spontaneous activity in the resting brain, especially those involving self-relevance. This study aims to investigate the neural correlates of value hierarchies from the perspective of typology.MethodsA total of 610 Chinese college students (30.31% women), aged 18 to 23, completed the personal values questionnaire and underwent resting-state functional magnetic resonance imaging.ResultsThe latent profile analysis revealed three personal value profiles: traditional social orientation, modernized orientation, and undifferentiated orientation. Neuroimaging results revealed that individuals with modernized orientation prioritized openness to change value, and this personal-focus is related to the higher low-frequency amplitude of the posterior insula; individuals with traditional social orientation prioritized self-transcendence and conservation values, and this social-focus is related to the stronger functional connectivity of the middle insula with the inferior temporal gyrus, temporal gyrus, posterior occipital cortex, and basal ganglia, as well as weaker functional connections within the right middle insula.DiscussionTaken together, these findings potentially indicate the intra-generational differentiation of contemporary Chinese emerging adults’ value hierarchies. At the neural level, these are correlated with brain activities involved in processing self- and other-relevance

    Acute Kidney Injury Biomarkers for Patients in a Coronary Care Unit: A Prospective Cohort Study

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    Background: Renal dysfunction is an established predictor of all-cause mortality in intensive care units. This study analyzed the outcomes of coronary care unit (CCU) patients and evaluated several biomarkers of acute kidney injury (AKI), including neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18) and cystatin C (CysC) on the first day of CCU admission. Methodology/Principal Findings: Serum and urinary samples collected from 150 patients in the coronary care unit of a tertiary care university hospital between September 2009 and August 2010 were tested for NGAL, IL-18 and CysC. Prospective demographic, clinical and laboratory data were evaluated as predictors of survival in this patient group. The most common cause of CCU admission was acute myocardial infarction (80%). According to Acute Kidney Injury Network criteria, 28.7 % (43/150) of CCU patients had AKI of varying severity. Cumulative survival rates at 6-month follow-up following hospital discharge differed significantly (p,0.05) between patients with AKI versus those without AKI. For predicting AKI, serum CysC displayed an excellent areas under the receiver operating characteristic curve (AUROC) (0.89560.031, p,0.001). The overall 180-day survival rate was 88.7 % (133/150). Multiple Cox logistic regression hazard analysis revealed that urinary NGAL, serum IL-18, Acute Physiology, Age and Chronic Health Evaluation II (APACHE II) and sodium on CCU admission day one were independent risk factors for 6-month mortality. In terms of 6-month mortality, urinary NGAL had the best discriminatory power, the best Youden index, and the highest overall correctness of prediction
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