Top quark mass and property measurements at Tevatron

The top quark, discovered in 1995 at the Fermilab Tevatron collider from CDF and D0 experiments, remains by far the most interesting particle to test standard model because of its large mass and unique properties. Having data collected about 10 fb$^{-1}$ of integrated luminosity of $p\bar{p}$ collision, both experiments have been studied the top quark in all the possible directions. In this article, we present the recent measurements of the top quark properties from Tevatron including the mass, width, spin correlation, and $W$ boson helicity using $t\bar{t}$ signature.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 4 pages, 6 figur

Top-Quark Mass Measurement in the Dilepton Channel Using {\it in situ} Jet Energy Scale Calibration

We employ a top-quark mass measurement technique in the dilepton channel with {\it in situ} jet energy scale calibration. Three variables having different jet energy scale dependences are used simultaneously to extract not only the top-quark mass but also the energy scale of the jet from a single likelihood fit. Monte Carlo studies with events corresponding to an integrated luminosity of 5 fb$^{-1}$ proton-proton collisions at the Large Hadron Collider $\sqrt{s} = 7$ TeV are performed. Our analysis suggests that the overall jet energy scale uncertainty can be significantly reduced and the top-quark mass can be determined with a precision of less than 1 GeV/c$^2$, including jet energy scale uncertainty, at the Large Hadron Collider.Comment: Submitted to Phys. Rev.

Top physics at Tevatron

The top quark, discovered in 1995 at the Fermilab Tevatron collider from CDF and D0 experiments, remains by far the most interesting particle to test standard model. Having data collected more than 7 fb−1 of integrated luminosity of p¯p collision, both experiments have been studied the top quark in all the possible directions. In this article, we present the recent measurements of the top quark properties including the mass, width, spin correlation, and W helicity as well as new particle searches using t¯t signature

Side-View Operando Optical Microscopy Analysis of a Graphite Anode to Study Its Kinetic Hysteresis

Operando analyses have provided several breakthroughs in the construction of high-performance materials and devices, including energy storage systems. However, despite the advances in electrode engineering, the formidable issues of lithium intercalation and deintercalation kinetics cannot be investigated by using planar observations. This study concerns side-view operando observation by optical microscopy of a graphite anode based on its color changes during electrochemical lithiation. Since the graphite color varies according to the optical energy gap during lithiation and delithiation, this technique can be used to study the corresponding charge-discharge kinetics. In addition, the cell configuration uses liquid electrolytes similar to commercial cells, allowing practical application. Furthermore, this side-view observation has shown that microscale spatial variations in rate and composition control the insertion and deinsertion, revealing the kinetics throughout the whole electrode. The results of this study could enhance the fundamental understanding of the kinetics of battery materials

Solar and supernova neutrino physics with future NaI(Tl) dark matter search detectors

We investigate the prospects for measuring the coherent elastic neutrino-nucleus scattering of solar and supernova neutrinos in future NaI(Tl) dark matter detection experiments. Considering the reduced background and improved light yield of the recently developed NaI(Tl) crystals, more than 3$\sigma$ observation sensitivities of the supernova neutrino within the Milky Way are demonstrated. In the case of the solar neutrino, approximately 3 observations are marginal with a 1 ton NaI(Tl) experiment assuming an order of magnitude reduced background, five photoelectron thresholds, and 5-year data exposure

Interests, Institutions, and Trade Politics in Democracies.

My dissertation develops a theoretical framework explaining variations in the structure of trade protection within and across countries. Much of the literature on trade policy has exclusively focused on either interest group influence on sectoral protection or the effects of domestic political institutions on trade openness at the national level. Unlike previous research, my dissertation aims to explain the ways in which the partisan and electoral incentives of representative policymakers affect the allocation of protectionist rents across domestic constituencies. I argue that the structure of trade barriers depends on the strategic context shaped by two factors: first, the economic characteristics of domestic constituencies that shape their trade policy preferences; second, electoral institutions and conditions which define the political importance of domestic constituencies to representative policymakers. To test the validity of my arguments, I conduct a set of empirical tests. Chapters 3-5 analyze within-country variation in protection across electoral constituencies and industries in the United States from 1989 through 2004. Using sectoral data on tariff and nontariff protection, district-level election outcomes, and geographical data on the distribution of industrial employment, I evaluate the extent to which protectionist demands of domestic constituencies and their electoral characteristics explain the allocation of protectionist rents across the electorate. My findings demonstrate that competitive constituencies tends to receive higher levels of tariff protection than safe constituencies and that electoral competitiveness increases the marginal effects of protectionist interests on trade policy outcomes both at the district and industry level. Chapter 6 examines variation in the skill-bias of tariff protection across countries. I maintain that the extent to which governments provide higher tariff rates for skill-intensive industries over unskilled-intensive industries is influenced by two factors: first, a country’s factor endowments that determine the median voter’s sector-specific trade policy preference; and, second, the level of political particularism in electoral systems. My empirical analysis shows that the skill-bias of tariff protection tends to be lower in candidate-centered electoral systems which induce legislators to build personal support bases and that an increase in the national capital-labor ratio moderates the effects of political particularism on the skill-bias of tariff structure.PHDPolitical ScienceUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/95938/1/suhyun_1.pd

Contribution of the family environment to depression in Korean adults with epilepsy

AbstractPurposeDepression is common in adults with epilepsy and an important factor that affects quality of life in these individuals. However, there are few studies on the interactions between epilepsy and family factors in adults and we here investigate this association.MethodsThis cross-sectional, multicenter study collected data on 391 adults with epilepsy and their caregivers recruited from 27 hospitals throughout Korea. The Beck Depression Inventory (BDI), Stigma Scale, and Caregiver Burden Inventory (CBI) were used to evaluate the study population. Multivariate analysis was conducted using hierarchical linear regression. The Sobel test and structural equation modeling were used to examine interrelationships among the potential factors.ResultsThe mean patient BDI score was 16.3 (SD=11.1). Depressive symptoms (BDI≥10) were in 68.3% and 57.0% in patients and their caregivers, respectively. Hierarchical linear regression analysis only identified caregiver BDI (β=0.219; p<0.001) as an independent factor related to patient BDI. The mediational model suggested that caregiver BDI mediated the effects of other family factors on patient BDI: caregiver's educational level (p=0.002), caregiver's CBI score (p<0.001), caregiver's Stigma Scale score (p<0.001), and family APGAR score (p<0.001). In addition, structural equation modeling showed that the relation between caregiver and patient BDI was unidirectional.ConclusionCaregiver depression is the most important contributor to depression in adults with epilepsy. The other family factors such as caregiver's perception of burden and the level of family function are indirectly correlated with patient depression via the mediating effects of caregiver depression