5,406 research outputs found
Seesaw mirroring between light and heavy Majorana neutrinos with the help of the reflection symmetry
In the canonical seesaw mechanism we require the relevant neutrino mass terms
to be invariant under the charge-conjugation transformations of left-
and right-handed neutrino fields. Then both the Dirac mass matrix and the right-handed neutrino mass matrix are well
constrained, so is the effective light Majorana neutrino mass matrix
via the seesaw formula. We find that these mass matrices can be classified into
22 categories, among which some textures respect the well-known -
permutation or reflection symmetry and flavor democracy. It is also found that
there exist remarkable structural equalities or similarities between
and , reflecting a seesaw mirroring relationship between light
and heavy Majorana neutrinos. We calculate the corresponding light neutrino
masses and flavor mixing parameters as well as the CP-violating asymmetries in
decays of the lightest heavy Majorana neutrino, and show that only the flavored
leptogenesis mechanism is possible to work for three categories of and in the reflection symmetry limit.Comment: 33 pages, 1 table. v2: matches the version accepted for publication
in JHE
On the Unitarity Triangles of the CKM Matrix
The unitarity triangles of the Cabibbo-Kobayashi-Maskawa (CKM)
matrix are studied in a systematic way. We show that the phases of the nine CKM
rephasing invariants are indeed the outer angles of the six unitarity triangles
and measurable in the -violating decay modes of and mesons.
An economical notation system is introduced for describing properties of the
unitarity triangles. To test unitarity of the CKM matrix we present some
approximate but useful relations among the sides and angles of the unitarity
triangles, which can be confronted with the accessible experiments of quark
mixing and violation.Comment: 9 Latex pages; LMU-07/94 and PVAMU-HEP-94-5 (A few minor changes are
made, accepted for publication in Phys. Lett. B
Production of the top-pions from the higgsless--top-Higgs model at the LHC
The top-pions() predicted by extra dimensional descriptions
of the topcolor scenario have similar feature with those in four dimensional
topcolor scenario, which have large Yukawa couplings to the third generation
quarks. In the context of the higgsless--top-Higgs(HTH) model, we discuss the
production of these new particles at the CERN Large Hadron Collider(LHC) via
various suitable mechanisms (gluon-gluon fusion, bottom-bottom fusion,
gluon-bottom fusion, and the usual Drell-Yan processes) and estimate their
production rates. We find that, as long as the top-pions are not too heavy,
they can be abundantly produced at the LHC. The possible signatures of these
new particles might be detected at the LHC experiments.Comment: 18pages, 6 figures, discussions and references added, typos correcte
The breaking of flavor democracy in the quark sector
The democracy of quark flavors is a well-motivated flavor symmetry, but it
must be properly broken in order to explain the observed quark mass spectrum
and flavor mixing pattern. We reconstruct the texture of flavor democracy
breaking and evaluate its strength in a novel way, by assuming a parallelism
between the Q=+2/3 and Q=-1/3 quark sectors and using a nontrivial
parametrization of the flavor mixing matrix. Some phenomenological implications
of such democratic quark mass matrices, including their variations in the
hierarchy basis and their evolution from the electroweak scale to a
superhigh-energy scale, are also discussed.Comment: 14 pages. References added. Accepted for publication in Chinese Phys.
GP-GAN: Gender Preserving GAN for Synthesizing Faces from Landmarks
Facial landmarks constitute the most compressed representation of faces and
are known to preserve information such as pose, gender and facial structure
present in the faces. Several works exist that attempt to perform high-level
face-related analysis tasks based on landmarks. In contrast, in this work, an
attempt is made to tackle the inverse problem of synthesizing faces from their
respective landmarks. The primary aim of this work is to demonstrate that
information preserved by landmarks (gender in particular) can be further
accentuated by leveraging generative models to synthesize corresponding faces.
Though the problem is particularly challenging due to its ill-posed nature, we
believe that successful synthesis will enable several applications such as
boosting performance of high-level face related tasks using landmark points and
performing dataset augmentation. To this end, a novel face-synthesis method
known as Gender Preserving Generative Adversarial Network (GP-GAN) that is
guided by adversarial loss, perceptual loss and a gender preserving loss is
presented. Further, we propose a novel generator sub-network UDeNet for GP-GAN
that leverages advantages of U-Net and DenseNet architectures. Extensive
experiments and comparison with recent methods are performed to verify the
effectiveness of the proposed method.Comment: 6 pages, 5 figures, this paper is accepted as 2018 24th International
Conference on Pattern Recognition (ICPR2018
Rare decays and in \the topcolor-assisted technicolor model
We examine the rare decays and in the
framework of the topcolor-assisted technicolor () model. The contributions
of the new particles predicted by this model to these rare decay processes are
evaluated. We find that the values of their branching ratios are larger than
the standard model predictions by one order of magnitude in wide range of the
parameter space. The longitudinal polarization asymmetry of leptons in can approach \ord(10^{-2}). The forward-backward asymmetry of leptons
in is not large enough to be measured in future experiments. We
also give some discussions about the branching ratios and the asymmetry
observables related to these rare decay processes in the littlest Higgs model
with T-parity.Comment: 29 pages, 9 figure, corrected typos, the version to appear in PR
Polarimetric Thermal to Visible Face Verification via Self-Attention Guided Synthesis
Polarimetric thermal to visible face verification entails matching two images
that contain significant domain differences. Several recent approaches have
attempted to synthesize visible faces from thermal images for cross-modal
matching. In this paper, we take a different approach in which rather than
focusing only on synthesizing visible faces from thermal faces, we also propose
to synthesize thermal faces from visible faces. Our intuition is based on the
fact that thermal images also contain some discriminative information about the
person for verification. Deep features from a pre-trained Convolutional Neural
Network (CNN) are extracted from the original as well as the synthesized
images. These features are then fused to generate a template which is then used
for verification. The proposed synthesis network is based on the self-attention
generative adversarial network (SAGAN) which essentially allows efficient
attention-guided image synthesis. Extensive experiments on the ARL polarimetric
thermal face dataset demonstrate that the proposed method achieves
state-of-the-art performance.Comment: This work is accepted at the 12th IAPR International Conference On
Biometrics (ICB 2019
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