5,618 research outputs found
More Anomalies from Fractional Branes
In this note we show how the anomalies of both pure and matter coupled N=1,2
supersymmetric gauge theories describing the low energy dynamics of fractional
branes on orbifolds can be derived from supergravity.Comment: 11 pages, latex; v2: minor typos fixe
Supersymmetry breaking at the end of a cascade of Seiberg dualities
We study the IR dynamics of the cascading non-conformal quiver theory on N
regular and M fractional D3 branes at the tip of the complex cone over the
first del Pezzo surface. The horizon of this cone is the irregular
Sasaki-Einstein manifold Y^{2,1}. Our analysis shows that at the end of the
cascade supersymmetry is dynamically broken.Comment: 12 pages, 2 figures, minor changes, typos correcte
CP violation as a probe of flavor origin in Supersymmetry
We address the question of the relation between supersymmetry breaking and
the origin of flavor in the context of CP violating phenomena. We prove that,
in the absence of the Cabibbo-Kobayashi-Maskawa phase, a general Minimal
Supersymmetric Standard Model with all possible phases in the soft-breaking
terms, but no new flavor structure beyond the usual Yukawa matrices, can never
give a sizeable contribution to , or
hadronic CP asymmetries. Observation of supersymmetric contributions to
CP asymmetries in B decays would hint at a non-flavor blind mechanism of
supersymmetry breaking.Comment: Reference added. 7 pages, no figure
Valles Marineris, Mars: Are pit chains formed by erosion and troughs by tectonism?
The origin of the Valles Marineris remains controversial. Erosional, tectonic, and hybrid processes have been proposed. To clarify these contradictions, the widths and depths of pit chains and troughs were compared and it was found that the features do not form a continuum. Rather, results are consistent with the hypothesis that pit chains formed by surficial collapse and troughs by deeper seated and coherent failure. All pit chains and linear depressions in the Valles Marineris region were classified by inspection into six morphologic categories: pit chains (linear arrays of small pits); floored chains (arrays of pit chains having flat or hummocky floors); scalloped troughs (wider linear depressions with scalloped wall segments); narrow troughs (depressions of intermediate width with straight wall segments); wide troughs (broad, linear depressions); and chaotic troughs (more irregular depressions displaying some channel morphologies). Topographic profiles were drawn across the classified depressions and the erosional width was determined between plateau margins along with the depth from the surrounding plateau level to the deepest part
An Examination of Behaviors and Attitudes toward Food Based on the Self-Reported Desire to Lose Weight: A Comparison of Two Groups in the United States and Italy
This research uses a survey instrument in the United States and Italy to examine the relationship between consumers’ demographics, attitudes, and behaviors toward food purchasing and their self-described desire to lose weight. Approximately two-thirds of consumers in the United States and slightly over half of consumers in Italy indicated a desire to lose weight. Married consumers with children in the household in both countries are more likely to desire to lose weight. Furthermore, consumers from both countries who desire to lose weight were more likely to agree that “the main meal of the day is the most important time of the day for my household.†Although the main meal of the day is more important to consumers from both countries who desire to lose weight, consumers in the United States who desire to lose weight were more likely to indicate that every member of their families eat the main meal together. Consumers in Italy who desire to lose weight were less likely to indicate that every member of their families eat the main meal together. The self-described overweight consumers in both countries enjoy cooking and have sufficient food for their families. However, the overweight consumer in the United States is often too busy to cook. This research finds no difference in the number of meals eaten away from home in a typical week between those in each country who desire to lose weight and those who do not. Furthermore, in the United States the sources of foods eaten away from home, such as fast food, are not related to the importance to the consumer of weight loss.Food Consumption/Nutrition/Food Safety, Health Economics and Policy,
Non-factorizable contributions to
It is pointed out that decays of the type have no
factorizable contributions, unless at least one of the charmed mesons in the
final state is a vector meson. The dominant contributions to the decay
amplitudes arise from chiral loop contributions and tree level amplitudes
generated by soft gluon emissions forming a gluon condensate. We predict that
the branching ratios for the processes ,
and are all of
order , while has a
branching ratio 5 to 10 times bigger. We emphasize that the branching ratios
are sensitive to corrections.Comment: 4 pages, 4 figures. Based on talk by J.O. Eeg at BEACH 2004, 6th
international conference on Hyperons, Charm and Beauty Hadrons, Illionois
Institute of Technology, Chicago, june. 27 - july 3, 200
Non-extremal fractional branes
We construct non-extremal fractional D-brane solutions of type-II string
theory at the Z_2 orbifold point of K3. These solutions generalize known
extremal fractional-brane solutions and provide further insights into N=2
supersymmetric gauge theories and dual descriptions thereof. In particular, we
find that for these solutions the horizon radius cannot exceed the non-extremal
enhancon radius. As a consequence, we conclude that a system of non-extremal
fractional branes cannot develop into a black brane. This conclusion is in
agreement with known dual descriptions of the system.Comment: 29 pages, LaTeX. v2: 30 pages; equation (3.4) corrected; typos fixed;
discussion in section 3 streamlined and slightly extended; reference adde
Grounding the case for a European approach to the regulation of automated driving: the technology-selection effect of liability rules
In the current paper, we discuss the need for regulation at EU level of Connected and Automated Driving solutions (henceforth CAD) based on multiple considerations, namely (i) the need for uniformity of criteria across European Member States, and (ii) the impact that regulation—or the absence of it—has on the proliferation of specific technological solutions. The analysis is grounded on legal and economic considerations of possible interactions between vehicles with different levels of automation, and shows how the existing framework delays innovation. A Risk-Management Approach, identifying one sole responsible party ex ante (one-stop-shop), liable under all circumstances—pursuant to a strict, if not absolute liability rule—is to be preferred. We analyse the solution adopted by some Member States in light of those considerations and conclude that none truly corresponds to a RMA approach, and differences will also cause market fragmentation. We conclude that because legal rules determine what kind of technological application is favoured over others—and thence they are not technology-neutral—uniformity across MSs is of essential relevance, and discuss possible policy approaches to be adopted at European level
Anomalies and Tadpoles in Open/Closed String Duality
We discuss the role played by the divergences appearing in the interaction
between a fractional D3 brane dressed with an SU(N) gauge field and a stack of
N fractional D3 branes on the orbifolds C^2/Z_2 and C^3/(Z_2 x Z_2). In
particular we show that the logarithmic divergences in the closed string
channel, interpreted as due to twisted massless tadpoles, are mapped, under
open/closed string duality, in the logarithmic ones in the open string channel,
due to the massless states circulating in the annulus diagram and corresponding
to the one-loop divergences that one finds in the gauge theory living in the
world volume of the brane. This result provides a quantitative evidence of why
the chiral and scale anomalies of the supersymmetric and non conformal gauge
theories supported by the world volume of the branes can be inferred from
supergravity calculations.Comment: LaTeX, 8 pages. Contribution to the proceedings of the workshop of
the RTN Network "The quantum structure of space-time and the geometric nature
of fundamental interactions", Copenhagen, September 200
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