1,328 research outputs found
Probing Supersymmetric Flavor Models with
We discuss the supersymmetric contribution to in various
supersymmetric flavor models. We find that in alignment models the
supersymmetric contribution could be significant while in heavy squark models
it is expected to be small. The situation is particularly interesting in models
that solve the flavor problems by either of the above mechanisms and the
remaining CP problems by means of approximate CP, that is, all CP violating
phases are small. In such models, the standard model contributions cannot
account for and a failure of the supersymmetric
contributions to do so would exclude the model. In models of alignment and
approximate CP, the supersymmetric contributions can account for
only if both the supersymmetric model parameters and the
hadronic parameters assume rather extreme values. Such models are then strongly
disfavored by the measurements. Models of heavy squarks
and approximate CP are excluded.Comment: 16 pages, harvmac. v2: We added a discussion of the intriguing
implications that would follow if a recent lattice result is confirme
An empirical analysis of habit and addiction to antibiotics
Because of bacterial resistance, current antibiotic consumption is reinforced by past use, and future utility is lower. The purpose of this article is to provide evidence on habit and addictive behavior toward antibiotics by exploring variations in the average consumption of antibiotics across 20 Italian regions. Using a balanced panel data set (2000-2009), we estimate myopic and rational addiction models, in which antibiotic consumption depends upon demographic and socioeconomic characteristics of the population, the supply of health care in the community, antibiotic price, and the "capital stockâ of endogenous bacterial resistance measured by past and future consumption. Our empirical evidence shows that past antibiotic consumption stimulates current consumption and is also consistent with the rational addiction hypothesis. The low price elasticity of antibiotic demand suggests that policy measures targeted at antibiotic co-payments may not be effective in controlling antibiotic consumption. There is scope for other policy interventions, such as incentives and information campaigns targeted at doctor
Stochastic Maximum Principle for optimal advertising models with delay and non-convex control space
In this paper we study optimal advertising problems that model the introduction of a new product into the market in the presence of carryover effects of the advertisement and with memory effects in the level of goodwill. In particular, we let the dynamics of the product goodwill to depend on the past, and also on past advertising efforts. We treat the problem by means of the stochastic Pontryagin maximum principle, that here is considered for a class of problems where in the state equation either the state or the control depend on the past. Moreover the control acts on the martingale term and the space of controls U can be chosen to be non-convex but now the space of controls U can be chosen to be non-convex. The maximum principle is thus formulated using a first-order adjoint Backward Stochastic Differential Equations (BSDEs), which can be explicitly computed due to the specific characteristics of the model, and a second-order adjoint relation
Direct CP violation in K->3pi decays induced by SUSY chromomagnetic penguins
An analysis of the CP violating asymmetry in decays in
the Standard Model and, by means of the mass insertion approximation, in a wide
class of possible supersymmetric extensions, is presented. We find that the
natural order of magnitude for this asymmetry is \cO(10^{-5}) in both cases.
Within supersymmetric models effects as large as \cO(10^{-4}) are possible,
but only in a restricted range of the relevant parameters.Comment: Latex, 11 pages, 1 figur
Two-body nonleptonic B decays in the Standard Model and beyond
We briefly discuss the phenomenology of B to pi pi, B to K pi and B to phi K
decays in the Standard Model and in Supersymmetry.Comment: 7 pages, 2 figures, uses moriond.sty. Talk given by L. Silvestrini at
the XXXIXth Rencontres de Moriond on ElectroWeak Interactions and Unified
Theories, La Thuile, Aosta Valley, Italy, March 21st-28th 200
Fermion Virtual Effects in Cross Section
We analyse the contribution of new heavy virtual fermions to the cross section. We find that there exists a relevant
interplay between trilinear and bilinear oblique corrections. The result
strongly depends on the chiral or vector--like nature of the new fermions. As
for the chiral case we consider sequential fermions: one obtains substantial
deviation from the Standard model prediction, making the effect possibly
detectable at or GeV linear colliders. As an example for
the vector--like case we take a SUSY extension with heavy charginos and
neutralinos: due to cancellation, the final effect turns out to be negligible.Comment: uuencoded, gz-compressed, tar-ed file. 8 pages, 4 EPS figures, uses
EPSFIG.ST
Increasing smoking cessation adherence: Do we need to consider the role of executive function and rumination?
Despite the cost and health consequences, a large number of people continue to smoke cigarettes worldwide every day. Notwithstanding, there have been a number of interventions to help people stop smoking but, in general, these have produced only limited success, and better interventions are needed. Accruing evidence affirmed that rumination and executive function play a pivotal role in cigarette smoking behavior, and in this editorial, we describe and discuss the key findings between these constructs and smoking, and argue that an impairment in executive functions does not act alone, but interacts with rumination by directing attention to depressive thoughts, thereby reducing the ability of smokers to engage in constructive behaviors, such as quitting smoking. Finally, we offer a new theory-driven model based on a deep understanding of the interactions between executive functions and rumination and potential moderator effects
Hybrid Inflation from Supersymmetric SU(5)
A scheme of hybrid inflation is considered in the framework of the minimal
supersymmetric SU(5) model with an extra singlet. The relevant role of the
cubic term in the adjoint representation in the renormalizable superpotential
is pointed out in order to have a quite wide region of initial conditions
compatible with inflation efficiency, monopole density and perturbations
constraint.Comment: Latex file, 12 pages, 2 figures, revised version with discussion of
mass spectrum extended and computation of the spectral index adde
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