956 research outputs found
Kadanoff-Baym approach to the thermal resonant leptogenesis
Using the non-equilibrium Green function method (Kadanoff-Baym equations) in
the expanding universe, we investigate evolution of the lepton number asymmetry
when the right-handed (RH) neutrinos have almost degenerate masses
. The resonantly enhanced -violating parameter
associated with the decay of the RH neutrino is obtained.
It is proportional to an enhancement factor with the regulator . The result is consistent with the previous result obtained by Garny
et al., in a constant background with an out-of-equilibrium initial state. We
discuss the origin of such a regulator, and why it is not like .Comment: 51 pages + appendices (46 pages), 5 figures; typos corrected,
references adde
Neck Dissection for Thoracic Esophageal Squamous Cell Carcinoma
Subtotal esophagectomy with extended lymph node dissection is a standard procedure for thoracic esophageal squamous cell carcinoma. Three-field lymphadenectomy, including neck dissection, is a standard type of lymph node dissection for complete clearance of tumor cells. Based on various series of analyses for lymph node metastases, the appropriate indication for neck dissection has been clarified. Herein, we describe the established techniques of neck dissection and review recent topics of three-field lymph node dissection for thoracic esophageal squamous cell carcinoma
Entanglement Generation and Decoherence in a Two-Qubit System Mediated by Relativistic Quantum Field
Motivated by the Bose et al.-Matletto-Vedral (BMV) proposal for detecting
quantum superposition of spacetime geometries, we study a toy model of a
quantum entanglement generation between two spins (qubits) mediated by a
relativistic free scalar field. After time evolution, spin correlation is
generated through the interactions with the field. Because of the associated
particle creation into an open system, the quantum state of spins is partially
decohered. In this paper, we give a comprehensive study of the model based on
the closed-time path formalism, focussing on relativistic causality and quantum
mechanical complementarity. We calculate various quantities such as spin
correlations, entanglement entropies, mutual information and negativity, and
study their behaviors in various limiting situations. In particular, we
calculate the mutual information of the two spins and compare it with spin
correlation functions. We also discuss why no quantum entanglement can be
generated unless both spins are causally affected by one another while spin
correlations are generated.Comment: 45 pages, 19 figure
CASE STUDY ON ATTITUDE AND BEHAVIOR OF SCHOOL LUNCH OFFICIALS REGARDING UTILIZATION OF LOCAL PRODUCE -FOCUSING ON THE DIFFERENCE OF OCCUPATION
This study was conducted in January 2010 to identify influential factors for utilization of local produce in school lunch services and factor-correlations in terms of employment types and item types and to review the evaluation index for shokuiku. The research participants were 56 nutrition teachers, 91 school principals, and 23 school lunch directors. The study revealed that school lunch staff had high awareness and behavioral motivation for using local ingredients. School lunch directors were concerned about managerial aspects such as “high price” and “not enough variety and quantity” for making lunches with local ingredients only. The principals expressed high opinion on educational or administrative advantages of using local ingredients in “increased number of local cuisine in the menu” and “securing food safety” but showed low awareness on problems related to using local produce to cook for entire student body such as “longer cooking time” and “not enough providers.” Correlation between questionnaire items revealed that there was a strong positive relation between items emphasizing advantages of using local produce. The results showed that using local produce for providing school lunches could induce changes in behaviors, such as frequenting local produce markets, and it is considered to become a good evaluation index for developing shokuiku
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