Doctor of Philosophy in Physics

dissertationThe purpose of this dissertation is to provide high-precision lattice quantum chromodynamics (QCD) simulation results for the mass splittings of low-lying charmonium states as the test of the Standard Model, and, further, to study the nature of a higher mass charmonium-like state called X(3872). Since the discovery of charmonium, it has played an important role in the study of QCD. However, it had been impossible to study charmonium energy levels at a low energy regime in QCD perturbative theory due to color connement, which is the consequence of the SU(3) nonabelian gauge theory in QCD. From this point of view, numerical simulation with lattice QCD is a unique method that provides a nonperturbative, ab initio approach for studying hadronic states governed by the strong interactions. In this dissertation, I describe a high-precision study of the splittings of the low-lying charmonium states, particularly the 1S and 1P states, including a chiral-continuum extrapolation. The highly excited charmonium states, discovered in the past decade, are much more challenging to study because their energy levels lie near or above the D^0 D^0 threshold, so they cannot be explained within the conventional quark model. Among those, we are interested in the narrow charmonium-like state, X(3872), due to its closeness to the DD* threshold and its possible four-quark nature. Since the X(3872) mass is within 1 MeV of the DD* threshold, it is a strong candidate for a DD* molecular state. Therefore, we use interpolating operators including both the conventional, excited P-wave charmonium state, Xc1, and the DD* open charm state for the isospin 0 channel. I provide the theoretical background for the lattice calculation and the corresponding methodologies, report on our high-precision results for the mass splittings of low-lying charmonium states, I introduce a new methodology called the \staggered variational method"", which is a variational method applied to the staggered fermion formalism, and nally, I present the simulation results for the X(3872) with quantum numbers J^{PC} = 1^{++} and isospin 0, using lattice QCD, as well as the detailed analysis and our interpretation to reveal the physical nature of X(3872)

Ferromagnetism in Mn-doped Chalcopyrite AlGaP2 Semiconductor

The electronic property and the magnetism of AlGaMnP2 compound by 3.125 %, 6.25 %, and 9.375 % Mn concentrations were investigated using the first-principles calculations. The Mn-doped AlGaP2 chalcopyrite with or without defect of Al, Ga, or P atom yields a strong half-metallic ground state. The ferromagnetic state is the most energetically favorable one. The spin-polarization of Mn dopant is stable with a magnetic moment close to 4μB due to intra-atomic exchange coupling. The states of host Al, Ga, or P atoms at the Fermi level are mainly a P-3p character, which mediates a strong interaction between the Mn-3d and P-3p states. The ferromagnetic state with high magnetic moment is originated from the hybridized P(3p)-Mn(3d)-P(3p) interaction formed through the p-d coupling without the defects. It is noted that the ferromagnetism arises from two distinguishing characteristics by polarons and by holes-mediated exchange-coupling

Low lying charmonium states at the physical point

We present results for the mass splittings of low-lying charmonium states from a calculation with Wilson clover valence quarks with the Fermilab interpretation on an asqtad sea. We use five lattice spacings and two values of the light sea quark mass to extrapolate our results to the physical point. Sources of systematic uncertainty in our calculation are discussed and we compare our results for the 1S hyperfine splitting, the 1P-1S splitting and the P-wave spin orbit and tensor splittings to experiment.Comment: For the Fermilab Lattice and MILC Collaborations; 7 pages, 6 figures; Contribution to the 32nd International Symposium on Lattice Field Theory, 23-28 June, 2014, Columbia University New York, N

Charmonium mass splittings at the physical point

We present results from an ongoing study of mass splittings of the lowest lying states in the charmonium system. We use clover valence charm quarks in the Fermilab interpretation, an improved staggered (asqtad) action for sea quarks, and the one-loop, tadpole-improved gauge action for gluons. This study includes five lattice spacings, 0.15, 0.12, 0.09, 0.06, and 0.045 fm, with two sets of degenerate up- and down-quark masses for most spacings. We use an enlarged set of interpolation operators and a variational analysis that permits study of various low-lying excited states. The masses of the sea quarks and charm valence quark are adjusted to their physical values. This large set of gauge configurations allows us to extrapolate results to the continuum physical point and test the methodology.Comment: 7 pp, 6 figs, Lattice 201

The Logical Form : A Theory and Its Application to German

The purpose of this paper is to present a method of semantic interpretation of the logical form (LF) which has recently been developed in the GB-Theory. For this purpose we develop two kinds of indexing filter mechanisms. Only the well-formed LFs of the sentences which are filtered out from the S-Structures and the LFs by the two indexing filter mechanisms are translated into the structures of the languages of intensional logic. We will call this structure of intensional logic the LF's. We exemplify in this paper some translation rules based on Bartsch (1977, 1979). There are several new rules developed in this paper, for instance, rules for translating controlled PRO and arbitray PRO, rules for translating null B-role terms, rules for translating quantifier phrases and their variables left by quantifier raising, and rules for detransitivization, etc

The small mixing angle θ13\theta_{13} and the lepton asymmetry

We present the correlation of low energy CP phases, both Dirac and Majorana, and the lepton asymmetry for the baryon asymmetry in the universe, with a certain class of Yukawa matrices that consist of two right-handed neutrinos and include one texture zero in themselves. For cases in which the amount of the lepton asymmetry $Y_L$ turns out to be proportional to $\theta_{13}^2$, we consider the relation between two types of CP phases and the relation of $Y_L$ versus the Jarlskog invariant or the amplitude of neutrinoless double beta decay as $\theta_{13}$ varies.Comment: 17 pages, 14 figures, information for figures added, version published in PR

Effect of Emotional Labor and Stress on Premenstrual Syndrome among Hospital Nurses

PURPOSE: This study is an explorative survey to examine emotional labor, stress, and premenstrual syndrome among hospital nurses and to examine relationships among them. METHODS: Data were collected from 228 nurses working at hospitals using structured questionnaires from September to October, 2014. Data were analyzed using SPSS 21.0 by frequency, descriptive statistics, t-test, one-way ANOVA, and Pearson's correlation coefficient. RESULTS: Score of emotional labor was different by work time per week (F=4.03, p=.019), and menstrual amount (F=5.18, p=.006). Level of stress was different by marital status (t=2.29, p=.023), pattern of work (t=-3.63, p<.001), work time per week (F=3.39, p=.035), regularity of menstrual cycle (t=-4.20, p<.001), and exercise frequency (F=4.28, p=.015). Scores of premenstrual syndrome were different by regularity of menstrual cycle (t=-3.18, p=.002), and menstrual amount (F=5.88, p=.003). Emotional labor was related with perceived stress (r=.40, p<.001) and premenstrual syndrome (r=.23, p<.001). Also, perceived stress was related with premenstrual syndrome (r=.33, p<.001). CONCLUSION: Nurses' emotional labor, stress, and premenstrual syndrome were higher than the average. Emotional labor was correlated with stress and premenstrual syndrome, premenstrual syndrome with stress. This study shows that it is necessary to understand these relationships and to search for nursing intervention to ease emotional labor, stress, and premenstrual syndrome