629 research outputs found
The accuracy of merging approximation in generalized St. Petersburg games
Merging asymptotic expansions of arbitrary length are established for the
distribution functions and for the probabilities of suitably centered and
normalized cumulative winnings in a full sequence of generalized St. Petersburg
games, extending the short expansions due to Cs\"org\H{o}, S., Merging
asymptotic expansions in generalized St. Petersburg games, \textit{Acta Sci.
Math. (Szeged)} \textbf{73} 297--331, 2007. These expansions are given in terms
of suitably chosen members from the classes of subsequential semistable
infinitely divisible asymptotic distribution functions and certain derivatives
of these functions. The length of the expansion depends upon the tail
parameter. Both uniform and nonuniform bounds are presented.Comment: 30 pages long version (to appear in Journal of Theoretical
Probability); some corrected typo
Bi-large Neutrino Mixing and Mass of the Lightest Neutrino from Third Generation Dominance in a Democratic Approach
We show that both small mixing in the quark sector and large mixing in the
lepton sector can be obtained from a simple assumption of universality of
Yukawa couplings and the right-handed neutrino Majorana mass matrix in leading
order. We discuss conditions under which bi-large mixing in the lepton sector
is achieved with a minimal amount of fine-tuning requirements for possible
models. From knowledge of the solar and atmospheric mixing angles we determine
the allowed values of sin \theta_{13}. If embedded into grand unified theories,
the third generation Yukawa coupling unification is a generic feature while
masses of the first two generations of charged fermions depend on small
perturbations. In the neutrino sector, the heavier two neutrinos are model
dependent, while the mass of the lightest neutrino in this approach does not
depend on perturbations in the leading order. The right-handed neutrino mass
scale can be identified with the GUT scale in which case the mass of the
lightest neutrino is given as (m_{top}^2/M_{GUT}) sin^2 \theta_{23} sin^2
\theta_{12} in the limit sin \theta_{13} = 0. Discussing symmetries we make a
connection with hierarchical models and show that the basis independent
characteristic of this scenario is a strong dominance of the third generation
right-handed neutrino, M_1, M_2 < 10^{-4} M_3, M_3 = M_{GUT}.Comment: typos correcte
Rearranging Edgeworth-Cornish-Fisher Expansions
This paper applies a regularization procedure called increasing rearrangement
to monotonize Edgeworth and Cornish-Fisher expansions and any other related
approximations of distribution and quantile functions of sample statistics.
Besides satisfying the logical monotonicity, required of distribution and
quantile functions, the procedure often delivers strikingly better
approximations to the distribution and quantile functions of the sample mean
than the original Edgeworth-Cornish-Fisher expansions.Comment: 17 pages, 3 figure
Possible Gauge Theoretic Origin for Quark-Lepton Complementarity
Similarity between the weak interaction properties of quarks and leptons has
led to suggestions that the origin of lepton mixing angles may be related to
those of quarks. In this paper, we present a gauge model based on group that leads to a new form for the quark
lepton complementarity which predicts the solar neutrino mixing angle in terms
of the Cabibbo angle for the case of inverted mass hierarchy for neutrinos. We
also indicate how these ideas can be implemented in an inspired
trinification model, which is more
closely allied to string theory by the AdS/CFT correspondence.Comment: 9 pages, latex, no figures; presentation improved; results unchanged;
minor typos correcte
b -> s gamma in the left-right supersymmetric model
The rare decay is studied in the left-right supersymmetric
model. We give explicit expressions for all the amplitudes associated with the
supersymmetric contributions coming from gluinos, charginos and neutralinos in
the model to one-loop level. The branching ratio is enhanced significantly
compared to the standard model and minimal supersymmetric standard model values
by contributions from the right-handed gaugino and squark sector. We give
numerical results coming from the leading order contributions. If the only
source of flavor violation comes from the CKM matrix, we constrain the scalar
fermion-gaugino sector. If intergenerational mixings are allowed in the squark
mass matrix, we constrain such supersymmetric sources of flavor violation. The
decay sets constraints on the parameters of the model and
provides distinguishing signs from other supersymmetric scenarios.Comment: 12 figure
Flavor Alignment Solutions to the Strong CP Problem in Supersymmetry
An approach to solving the Strong CP Problem in supersymmetric theories is
discussed which uses abelian family symmetries to align the mass matrices of
the quarks and squarks. In this way both the Strong CP Problem and the
characteristic flavor and CP problems of supersymmetry can be solved in a
single way.Comment: 13 pages, LaTe
Signals of neutralinos and charginos from gauge boson fusion at the CERN Large Hadron Collider
We point out that interesting signals of the non-strongly interacting sector
of the supersymmetric standard model arise from the production of charginos and
neutralinos via vector boson fusion (VBF) at the Large Hadron Collider (LHC).
In particular, if R-parity is violated, the hadronically quiet signals of
charginos and neutralinos through direct production get considerably
suppressed. We show that in such cases, the VBF channel can be useful in
identifying this sector through clean and background-free final states.Comment: 10 pages Latex, 8 figures, minor changes in text and few references
added, to be published in Phys. Rev.
Reexamining nonstandard interaction effects on supernova neutrino flavor oscillations
Several extensions of the standard electroweak model allow new four-fermion
interactions (nu_a nu_b * ff) with strength eps_ab*G_F, where (a,b) are flavor
indices. We revisit their effects on flavor oscillations of massive
(anti)neutrinos in supernovae, in order to achieve, in the region above the
protoneutron star, an analytical treatment valid for generic values of the
neutrino mixing angles (omega,phi,psi)=(theta_12,theta_13,theta_23). Assuming
that eps_ab<<1, we find that the leading effects on the flavor transitions
occurring at high (H) and low (L) density along the supernova matter profile
can be simply embedded through the replacements phi-->phi+eps_H and
omega-->omega+eps_L, respectively, where eps_H and eps_L are specific linear
combinations of the eps_ab's. Similar replacements hold for eventual
oscillations in the Earth matter. From a phenomenological point of view, the
most relevant consequence is a possible uncontrolled bias (phi-->phi+eps_H) in
the value of the mixing angle phi inferred by inversion of supernova neutrino
data. Such a drawback, however, does not preclude the discrimination of the
neutrino mass spectrum hierarchy (direct or inverse) through supernova neutrino
oscillations.Comment: Text clarified, one figure added. To appear in PR
U(2)-like Flavor Symmetries and Approximate Bimaximal Neutrino Mixing
Models involving a U(2) flavor symmetry, or any of a number of its
non-Abelian discrete subgroups, can explain the observed hierarchy of charged
fermion masses and CKM angles. It is known that a large neutrino mixing angle
connecting second and third generation fields may arise via the seesaw
mechanism in these models, without a fine tuning of parameters. Here we show
that it is possible to obtain approximate bimaximal mixing in a class of models
with U(2)-like Yukawa textures. We find a minimal form for Dirac and Majorana
neutrino mass matrices that leads to two large mixing angles, and show that our
result can quantitatively explain atmospheric neutrino oscillations while
accommodating the favored, large angle MSW solution to the solar neutrino
problem. We demonstrate that these textures can arise in models by presenting a
number of explicit examples.Comment: 20 pages RevTex4, 2 figure
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