2,935 research outputs found

    Monopole confinement by flux tube

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    We revisit Nambu's model of quark confinement by a tube of magnetic flux, with two additional features. The quarks are taken to be magnetic monopoles external to the tube, which seal the ends, and are also taken to be fermions. This ensures that the model is inconsistent unless there are at least two species of fermions being confined.Comment: 7pp; brief additions relating monopole strength to winding number, and discussion on length of stable flux tube; one reference adde

    Surface holonomy and gauge 2-group

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    Just as point objects are parallel transported along curves, giving holonomies, string-like objects are parallel transported along surfaces, giving surface holonomies. Composition of these surfaces correspond to products in a category theoretic generalization of the gauge group, called a 2-group. I consider two different ways of constructing surface holonomies, one by using a pair of one and two form connections, and another by using a pair of one-form connections. Both procedures result in the structure of a 2-group.Comment: 8pp, RevTeX4, Submitted upon invitation to IJGMM

    Gap bootstrap methods for massive data sets with an application to transportation engineering

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    In this paper we describe two bootstrap methods for massive data sets. Naive applications of common resampling methodology are often impractical for massive data sets due to computational burden and due to complex patterns of inhomogeneity. In contrast, the proposed methods exploit certain structural properties of a large class of massive data sets to break up the original problem into a set of simpler subproblems, solve each subproblem separately where the data exhibit approximate uniformity and where computational complexity can be reduced to a manageable level, and then combine the results through certain analytical considerations. The validity of the proposed methods is proved and their finite sample properties are studied through a moderately large simulation study. The methodology is illustrated with a real data example from Transportation Engineering, which motivated the development of the proposed methods.Comment: Published in at http://dx.doi.org/10.1214/12-AOAS587 the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Top Yukawa coupling measurement with indefinite CP Higgs in e+ettˉΦe^+e^-\to t\bar{t}\Phi

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    We consider the issue of the top quark Yukawa coupling measurement in a model in dependent and general case with the inclusion of CP-violation in the coupling. Arguably the best process to study this coupling is the associa ted production of Higgs boson along with a ttˉt\bar t pair in a machine like the International Linear Collider (ILC). While detailed analyses of the sensitivity of the measurement assuming a Standard Model (SM) - like coupling are available in the context of ILC, conclude that th e coupling could be pinned down at about 10\% level with modest luminosity, our investigations show that the scenario could be different in case of a more general coupling. The modified Lorentz structure resulting in a changed functional dependence of the cross section on the couplin g, along with the difference in the cross section itself leads to considerable deviation in the sensitivity. Our studies with an ILC of center of mass energies of 500 GeV, 800 GeV and 1000 GeV show that moderate CP-mixing in the Higgs sector could change the sensitivity to about 20\ %, while it could be worsened to 75\% in cases which could accommodate more dramatic changes in the coupling. While detailed considerations of the decay distributions point to a need for a relook at the analysis strategy followed for the case of SM such as for a model independent analysis of the top quark Yukawa coupling measurement. This study strongly suggests that, a joint analysis of the CP properties and the Yukawa coupling measurement would be the way forward at the ILC and that caution must be excercised in the measurem ent of the Yukawa couplings and the conclusions drawn from it.Comment: 18 pages, 7 figures, uses revte

    Parallel transport on non-Abelian flux tubes

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    I propose a way of unambiguously parallel transporting fields on non-Abelian flux tubes, or strings, by means of two gauge fields. One gauge field transports along the tube, while the other transports normal to the tube. Ambiguity is removed by imposing an integrability condition on the pair of fields. The construction leads to a gauge theory of mathematical objects known as Lie 2-groups, which are known to result also from the parallel transport of the flux tubes themselves. The integrability condition is also shown to be equivalent to the assumption that parallel transport along nearby string configurations are equal up to arbitrary gauge transformations. Attempts to implement this condition in a field theory leads to effective actions for two-form fields.Comment: significant portions of text rewritten, references adde

    Evaluation of maternal and perinatal morbidity and mortality in eclampsia by early termination of pregnancy

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     Background: Eclampsia is one of the leading causes of maternal mortality in India.Methods: A prospective observational study was done on 200 pregnant women admitted with antepartum eclampsia in Malda Medical College from 1 April 2017 to 30 October 2019. Group A included patients who delivered through vaginal route within 10 to 12 hrs of eclampsia by stabilisation of patients while Group B included subjects who underwent early caesarean section for uncontrolled convulsions or poor Bishop score. Maternal and perinatal outcomes were compared between the groups. Data was recorded in a pretested performa and was analyzed using appropriate statistical methods with SPSS.Results: Caesarean section (group B) was done in 130 cases (65%) while vaginal delivery (group A) was done in 65 cases (37.5%). Group A had higher maternal mortality (10.7%) in comparison to group B (4.6%) which was statistically not significant (p=0.1075). There were 32 neonatal deaths (24.6%) and 11 still births (8.46%) in group A while there were 12 neonatal deaths (18.46%) and 3 still births (4.61%) in group B. There was a statistically significant difference (p<0.0001) between the groups with respect to total perinatal deaths.Conclusions: Antenatal and intranatal eclampsia should be managed by early termination of pregnancy preferably with Caesarean section. Early presentation and timely decision to terminate pregnancy will improve the maternal and perinatal outcome

    Artificial neural network model with the parameter tuning assisted by a differential evolution technique: the study of the hold up of the slurry flow in a pipeline

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    This paper describes a robust hybrid artificial neural network (ANN) methodology which can offer a superior performance for the important process engineering problems. The method incorporates a hybrid artificial neural network and differential evolution technique (ANN-DE) for the efficient tuning of ANN meta parameters. The algorithm has been applied for the prediction of the hold up of the solid liquid slurry flow. A comparison with selected correlations in the literature showed that the developed ANN correlation noticeably improved the prediction of hold up over a wide range of operating conditions, physical properties, and pipe diameters
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