234,025 research outputs found
Naturalness, dark matter, and the muon anomalous magnetic moment in supersymmetric extensions of the standard model with a pseudo-Dirac gluino
We study the naturalness, dark matter, and muon anomalous magnetic moment in
the Supersymmetric Standard Models (SSMs) with a pseudo-Dirac gluino (PDGSSMs)
from hybrid and term supersymmetry (SUSY) breakings. To obtain the
observed dark matter relic density and explain the muon anomalous magnetic
moment, we find that the low energy fine-tuning measures are larger than about
30 due to strong constraints from the LUX and PANDAX experiments. Thus, to
study the natural PDGSSMs, we consider multi-component dark matter and then the
relic density of the lighest supersymmetric particle (LSP) neutralino is
smaller than the correct value. We classify our models into six kinds: (i) Case
A is a general case, which has small low energy fine-tuning measure and can
explain the anomalous magnetic moment of the muon; (ii) Case B with the LSP
neutralino and light stau coannihilation; (iii) Case C with Higgs funnel; (iv)
Case D with Higgsino LSP; (v) Case E with light stau coannihilation and
Higgsino LSP; (vi) Case F with Higgs funnel and Higgsino LSP. We study these
Cases in details, and show that our models can be natural and consistent with
the LUX and PANDAX experiments, as well as explain the muon anomalous magnetic
moment. In particular, all these cases except the stau coannihilation can even
have low energy fine-tuning measures around 10.Comment: 19 pages, 18 figure
Voices from the diaspora: changing hierarchies and dynamics of Chinese multilingualism
The so-called Chinese diasporas, i.e. Chinese communities outside Greater China (China, Hong Kong, Macau, and Taiwan), have traditionally been dialect dominant; that is, the vast majority of Chinese immigrants are speakers of (especially Southern) dialects. Cantonese and Hokkien are two of the most prominent dialects. With globalization and the rise of China as a world politico-economic power, the national, standardized variety, Putonghua, is gaining particular prestige amongst the Chinese diasporas. For example, all the Cantonese schools for British Chinese children in the UK now also teach Putonghua, but none of the Putonghua schools teach Cantonese. Using ethnographic interviews with and participant observation of Chinese people of different generations in various diasporic communities, this paper examines the changing hierarchies of varieties of Chinese, the implications of such changes for the education and identity development of the young, and the constitution of a (speech) community in the post-modern era. It focuses on language attitude and linguistic practices (including literacy practices). It also investigates the tensions between the competing ideologies and discourses on national and ethnic identities, nationalism, community relations and cultural values
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