33 research outputs found
Saturation of counterterms by resonances in decays
The decays , and are
reinvestigated within the framework of chiral perturbation theory. The
counterterms induced by strong, electromagnetic and weak interactions are
determined assuming the resonance exchange. The weak deformation model, the
factorization model and the large limit are used to create a weak
Lagrangian. It is found that the results of the first two approaches depend on
the coupling, defined in the effective chiral Lagrangian of the order. The set of parameters used in the extended Nambu and
Jona-Lasinio model can accommodete
decay rate within the factorization approach. The CP violating decay rate is discussed.Comment: 24 pages, LaTe
Phenomenology of flavor-mediated supersymmetry breaking
The phenomenology of a new economical SUSY model that utilizes dynamical SUSY
breaking and gauge-mediation (GM) for the generation of the sparticle spectrum
and the hierarchy of fermion masses is discussed. Similarities between the
communication of SUSY breaking through a messenger sector, and the generation
of flavor using the Froggatt-Nielsen (FN) mechanism are exploited, leading to
the identification of vector-like messenger fields with FN fields, and the
messenger U(1) as a flavor symmetry. An immediate consequence is that the first
and second generation scalars acquire flavor-dependent masses, but do not
violate FCNC bounds since their mass scale, consistent with effective SUSY, is
of order 10 TeV. We define and advocate a minimal flavor-mediated model (MFMM),
recently introduced in the literature, that successfully accommodates the small
flavor-breaking parameters of the standard model using order one couplings and
ratios of flavon field vevs. The mediation of SUSY breaking occurs via two-loop
log-enhanced GM contributions, as well as several one-loop and two-loop
Yukawa-mediated contributions for which we provide analytical expressions. The
MFMM is parameterized by a small set of masses and couplings, with values
restricted by several model constraints and experimental data. The
next-to-lightest sparticle (NLSP) always has a decay length that is larger than
the scale of a detector, and is either the lightest stau or the lightest
neutralino. Similar to ordinary GM models, the best collider search strategies
are, respectively, inclusive production of at least one highly ionizing track,
or events with many taus plus missing energy. In addition, D^0 - \bar{D}^0
mixing is also a generic low energy signal. Finally, the dynamical generation
of the neutrino masses is briefly discussed.Comment: 54 pages, LaTeX, 8 figure
Entropic force approach to noncommutative Schwarzschild black holes signals a failure of current physical ideas
Recently, a new perspective of gravitational-thermodynamic duality as an
entropic force arising from alterations in the information connected to the
positions of material bodies is found. In this paper, we generalize some
aspects of this model in the presence of noncommutative Schwarzschild black
hole by applying the method of coordinate coherent states describing smeared
structures. We implement two different distributions: (a) Gaussian and (b)
Lorentzian. Both mass distributions prepare the similar quantitative aspects
for the entropic force. Our study shows, the entropic force on the smallest
fundamental unit of a holographic screen with radius vanishes. As a
result, black hole remnants are unconditionally inert even gravitational
interactions do not exist therein. So, a distinction between gravitational and
inertial mass in the size of black hole remnant is observed, i.e. the failure
of the principle of equivalence. In addition, if one considers the screen
radius to be less than the radius of the smallest holographic surface at the
Planckian regime, then one encounters some unusual dynamical features leading
to gravitational repulsive force and negative energy. On the other hand, the
significant distinction between the two distributions is conceived to occur
around , and that is worth of mentioning: at this regime either our
analysis is not the proper one, or non-extensive statistics should be employed.Comment: 15 pages, 2 figures, new references added, minor revision, Title
changed, to appear in EPJ Plu