460 research outputs found
PAMELA data and leptonically decaying dark matter
No full textRecently PAMELA released their first results on the positron and antiproton ratios. Stimulated by the new data, we studied the cosmic ray propagation models and calculated the secondary positron and antiproton spectra. The low energy positron ratio can be consistent with data in the convection propagation model. Above similar to 10 GeV PAMELA data shows a clear excess on the positron ratio. However, the secondary antiproton is roughly consistent with the data. The positron excess may be evidence of dark matter annihilation or decay. We compare the positron and antiproton spectra with the data by assuming that dark matter annihilates or decays into different final states. The PAMELA data actually excludes quark pairs being the main final states, and disfavors gauge boson final states. Only in the case of leptonic final states can the positron and antiproton spectra be explained simultaneously. We also compare the decaying and annihilating dark matter scenarios which can account for the PAMELA results and find that the decaying dark matter is preferred. Finally, we consider a decaying neutralino dark matter model in the frame of supersymmetry with R-parity violation. The PAMELA data is well fitted with a neutralino mass of 600 similar to 2000 GeV and a lifetime of similar to 10(26) seconds. We also demonstrate that a neutralino with mass around 2 TeV can fit PAMELA and ATIC data simultaneously.Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)0REVIEW2null7
R-parity breaking via type II seesaw, decaying gravitino dark matter and PAMELA positron excess
No full textWe propose a new class of R-parity violating extension of MSSM with type 11 seesaw mechanism for neutrino masses where an unstable gravitino is the dark matter of the Universe. It decays predominantly into three leptons final states, thereby providing a natural explanation of the positron excess but no antiproton excess in the PAMELA experiment. The model can explain neutrino masses without invoking any high scale physics while keeping the pre-existing baryon asymmetry of the universe in tact. (C) 2009 Elsevier B.V. All rights reserved.Physics, MultidisciplinarySCI(E)40ARTICLE5311-31767
Richardson, Barbauld, and the construction of an early modern fan club
No full textMPhilMuch has been written about the life and long works of the eighteenth century epistolary novelist, Samuel Richardson, but the prospect of his position as the first celebrity novelist – responsible for courting his own fame as well as initiating his own fan club – has largely been ignored. The body of manuscripts housed at the National Art Library in the Victoria and Albert Museum in London provides the modern scholar with evidence of the skeletal beginnings of an early fan club. This thesis aims to show how these manuscripts were turned into a saleable commodity by the publisher and entrepreneur Richard Phillips, while under the guiding hand of another, slightly later, literary celebrity, Anna Laetitia Barbauld. In order to restore Richardson’s reputation amongst a new nineteenth century audience, Barbauld was required to construct her own idea of him as an eighteenth century celebrity author, and in doing so the insecurities of a self-professed, apparently diffident man, are revealed. Barbauld’s capacious, but heavily edited selection of letters is analyzed in this thesis, providing ample evidence that Richardson’s correspondents were more than just eager letter writers. By using Barbauld’s biography of Richardson this thesis aims to show how she manipulates the genre of life writing in her construction of him.
This thesis offers an alternative reading of how the Richardson manuscripts are viewed, redefining them as not simply a collection of letters, but as a collective entity, deliberately selected and archived as evidence of an early modern fan club, and its celebrity managing director
Parameters in a class of leptophilic dark matter models from PAMELA, ATIC and FERMI
No full textAbstractIn this work we study a class of leptophilic dark matter models, where the dark matter interacts with the standard model particles via the U(1)Li−Lj gauge boson, to explain the e± excess in cosmic rays observed by ATIC and PAMELA experiments, and more recently by Fermi experiment. There are three types of U(1)Li−Lj models: (a) U(1)Le−Lμ, (b) U(1)Le−Lτ, and (c) U(1)Le−Lτ. Although ATIC or Fermi data are consistent with PAMELA data separately, ATIC and Fermi data do not agree with each other. We therefore aim to identify which of the three models can explain which data set better. We find that models (a) and (b) can give correct dark matter relic density and explain the ATIC and PAMELA data simultaneously recur to the Breit–Wigner enhancement. Whereas model (c) with a larger Z′ mass can explain Fermi and PAMELA data simultaneously. In all cases the model parameters are restricted to narrow regions. Future improved data will decide which set of data is correct and also help to decide the correct dark matter model
ATIC and PAMELA results on cosmic e(+/-) excesses and neutrino masses
No full textRecently the ATIC and PAMELA collaborations released their results which show the abundant e(+/-) excess in cosmic rays well above the background, but not for the (p) over bar. Their data if interpreted as the dark matter particles' annihilation imply that the new physics with the dark matter is closely related to the lepton sector. In this paper we study the possible connection of the new physics responsible for the cosmic e(+/-) excesses to the neutrino mass generation. We consider a class of models and do the detailed numerical calculations. We find that some models can account for the ATIC and PAMELA e(+/-) and (p) over bar data and at the same time generate the small neutrino masses.Physics, Particles & FieldsSCI(E)0ARTICLE4nul
A coral ensemble record of the El Niño southern oscillation over the mid-to-late holocene
No full textThe El Niño-Southern Oscillation (ENSO) represents the largest source of year-to-year global climate extremes. However, its sensitivity to external climate forcing, whether natural or anthropogenic, is difficult to assess with available records. Paleoclimate reconstructions from the central tropical Pacific provide much-needed targets for climate models that are used to simulate future projections of ENSO variability under enhanced greenhouse emissions. Coral oxygen isotopes track variations in sea surface temperature and sea surface salinity, which is largely driven by ENSO. To date, paleo records rely on rare but decades-long fossil coral sequences that date to the last 7,000 years [Cobb et al., 2013]. This study turns to using abundant but shorter sequences (7-20yrs-long) of fossil coral rubble samples to produce a more statistically robust reconstruction of ENSO from the central tropical Pacific through the last 7,000 years. In Chapter 1, I provide relevant background information on ENSO in order to place this dissertation into broader scientific context. This includes the basics on ENSO dynamics and the different spatial patterns of El Niño events. I also explain the different proxies that have evolved our understanding of ENSO throughout the Holocene. Lastly, I mention where we currently are in understanding future projections of ENSO behavior under greenhouse gas emissions. In Chapter 2, I address one of the largest challenges in using a large number of fossil corals for paleoclimate reconstruction, which involves dating hundreds of coral samples cheaply and quickly. I compared the coral dating results from a rapid radiocarbon (14C) dating method, developed at the University of California Irvine, to high precision uranium-thorium (U/Th) dates, considered the gold standard of coral dating. The rapid 14C dating method allows for ~300 samples to be analyzed per week at 500/sample for U/Th dating. My results demonstrate the utility of employing 14C dating to screen large numbers of corals, followed by more limited U/Th dating on samples chosen for paleoclimate reconstruction. In addition, my extensive fossil coral dating has provided a map of fossil coral age distributions across Christmas Island in the central tropical Pacific. In Chapter 3, we extend the paleo-ENSO record through the generation of 16 new fossil coral δ18O timeseries, averaging 15yrs each, for a total of 233 years of data that greatly augment the available paleo-ENSO archive. Combining this new dataset with published data, we quantify the differences in natural variations in ENSO from the early mid-Holocene to present. In this study, we document a significant increase in recent ENSO variance as compared to the last 7,000 years, implying a role for greenhouse gases in driving an intensification of ENSO. We also find a significant reduction in ENSO variance of roughly 20% from 3,000-5,000yr before present, relative to the preceding and subsequent intervals of data. The causes of the late mid-Holocene reduction in ENSO variance may be linked to the influence of fall and/or spring equatorial insolation forcing, which perturbs the seasonal cycle at the critical growth and decay phases of ENSO extremes, respectively. In distinguishing between natural variability and forced changes in ENSO, we assess the significance of our results using a variety of different null hypotheses that includes output from both a statistical and dynamical model of ENSO variability. Our findings imply that ENSO is sensitive to external forcing, both natural and anthropogenic, although the precise mechanisms for such responses require further study. Our results imply that anthropogenic climate change likely contributed to the record-breaking 2015/2016 El Niño event, and that future ENSO variance is unlikely to decrease under continued greenhouse forcing. In Chapter 4, I conclude the major work presented in this study and highlight the next steps in this research towards understanding how mean climate has changed throughout the Holocene and how it affects ENSO variability.Ph.D
Arthur William Upfield: a biography
No full textThis dissertation is an exhaustive account of the life and work of Arthur William Upfield (1890-1964). It is presented as a critical biography and narrates the life of the writer, in his socio-cultural milieu, from birth. It also positions Upfield as a writer who dealt with issues of Aboriginality at a time when this was a singularly polemical subject. My work is informed by the theory of Zygmunt Bauman and others and is posited in the context of late-modern biography theory.
English-born, Upfield arrived in Australia in 1911 and took work in the bush, serving overseas with the Australian army at the outbreak of World War I and marrying an Australian army nurse in Egypt. Returning with his wife and son to Australia in 1921 he intermittently carried his swag until he was employed patrolling the Western Australian number 1 rabbit-proof fence for three years to 1931. By that time he had published four novels, including two crime novels featuring his fictional creation, the part-Aboriginal, part-European, Detective-Inspector Napoleon Bonaparte ('Bony'), arguably the first fully-developed character in Australian popular fiction.
Leaving the fence, Upfield settled with his family in Perth and wrote full-time until joining the Melbourne Herald in 1933. Retrenched, he resumed career writing to be further interrupted by a war-time intelligence posting in 1939. In 1943 the first Bony mysteries were published in America, where Upfield's critical success was maintained until his death. In 1945 he left his wife for Jessica Uren, to whom he remained devoted.
Upfield's in all twenty-nine Bony novels, many of which have been translated across eleven languages, afforded him notable success both at home and abroad, in good part due to his descriptive gifts and the uniqueness of his fictional character, the part-Aboriginal Bony
Decaying asymmetric dark matter relaxes the AMS-Fermi tension
No full textThe first result of AMS-02 confirms the positron fraction excess observed by PAMELA, but the spectrum is somewhat softer than that of PAMELA. In the dark matter (DM) interpretation it brings a tension between AMS-02 and Fermi-LAT, which reported an excess of the electron plus positron flux. In this work we point out that the asymmetric cosmic ray from asymmetric dark matter (ADM) decay relaxes the tension. It is found that in the case of two-body decay a bosonic ADM around 2.4 TeV and decaying into mu(-)tau(+) can significantly improve the fits. Based on the R-parity-violating supersymmetry with operators LLEe, we propose a minimal model to realize that ADM. The model introduces only a pair of singlets (X, (X) over bar) with a tiny coupling LHuX, which makes the ADM share the lepton asymmetry and decay into mu(-)tau(+) along the operator LLEe.Astronomy & AstrophysicsPhysics, Particles & FieldsSCI(E)5ARTICLE10nul
A critical analysis of the plays of Sarah Daniels.
No full textAs one of the forerunners of 'second wave' feminist playwriting, Sarah Daniels has for the
past fifteen years been one of Britain's most prolific writers for the stage. This thesis is the
first to offer a detailed critical analysis of all her published plays along with a developmental
account of her career. My approach throughout is text-based and non-prescriptive,
although I do at certain points indicate where Daniels reflects or voices differing feminist
perspectives. I also consider, beginning in Chapter Three, the critical reception and
'gendered' reviewing the playwright has received over the years.
The thesis is organised into five chapters with an Afterword. Chapter One, the
Introduction, offers an overview of Daniels' career as well as certain key characteristics of
her work. In Chapter Two I analyse the early plays, Ripen Our Darkness, The Devil's
Gateway and Neaptide, and consider in particular how they reflect, along with other
women's playwriting at the time, certain ideals of the Women's Liberation Movement.
Chapter Three is devoted entirely to Masterpieces, Daniels' most controversial and, on
many levels, successful play to date. Chapter Four is an analysis of the 'history plays',
Byrthrite and The Gut Girls. In addition to giving voice to women traditionally silenced in
and by history, these plays (especially Byrthrite) also echo particular strands of modern
feminist debate. Chapter Five examines Daniels' plays of the 1990s (Beside Herself, Head-
Rot Holiday and The Madness of Esme and Shaz) with their central theme of 'women and
madness'. This is also a fitting theme with which to conclude the thesis as it brings together
and expands on the most significant motif running throughout the playwright's work. In the
Afterword I consider the effect of Esme and Shaz's critical reception on Daniels, as well as
her current 'work in progress'. Finally, the two Appendices provide a chronological table of
Daniels' productions and a list of subsequent professional productions as well as awards
"Die erfrischende pause": Marketing Coca-Cola in Hitler's Germany
No full textThe chapter, ""Die erfrischende pause": Marketing Coca-Cola in Hitler's Germany" was written by Jeff R. Schutts (Douglas College Faculty). The sheer intensity and violence of Germany’s twentieth century—through the end of an empire, two world wars, two democracies, and two dictatorships—provide a unique opportunity to assess the power and endurance of commercial imagery in the most extreme circumstances. Selling Modernity places advertising and advertisements in this tumultuous historical setting, exploring such themes as the relationship between advertising and propaganda in Nazi Germany, the influence of the United States on German advertising, the use of advertising to promote mass consumption in West Germany, and the ideological uses and eventual prohibition of advertising in East Germany.
While the essays are informed by the burgeoning literature on consumer society, Selling Modernity focuses on the actors who had the greatest stake in successful merchandising: company managers, advertising executives, copywriters, graphic artists, market researchers, and salespeople, all of whom helped shape the depiction of a company’s products, reputation, and visions of modern life. The contributors consider topics ranging from critiques of capitalism triggered by the growth of advertising in the 1890s to the racial politics of Coca-Cola’s marketing strategies during the Nazi era, and from the post-1945 career of an erotica entrepreneur to a federal anti-drug campaign in West Germany. Whether analyzing the growing fascination with racialized discourse reflected in early-twentieth-century professional advertising journals or the postwar efforts of Lufthansa to lure holiday and business travelers back to a country associated with mass murder, the contributors reveal advertising’s central role in debates about German culture, business, politics, and society.book chapterPublished
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