5,406 research outputs found

    Seesaw mirroring between light and heavy Majorana neutrinos with the help of the S3S^{}_3 reflection symmetry

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    In the canonical seesaw mechanism we require the relevant neutrino mass terms to be invariant under the S3S^{}_3 charge-conjugation transformations of left- and right-handed neutrino fields. Then both the Dirac mass matrix MDM^{}_{\rm D} and the right-handed neutrino mass matrix MRM^{}_{\rm R} are well constrained, so is the effective light Majorana neutrino mass matrix MνM^{}_\nu via the seesaw formula. We find that these mass matrices can be classified into 22 categories, among which some textures respect the well-known μ\mu-τ\tau permutation or reflection symmetry and flavor democracy. It is also found that there exist remarkable structural equalities or similarities between MνM^{}_\nu and MRM^{}_{\rm R}, 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 MDM^{}_{\rm D} and MRM^{}_{\rm R} in the S3S^{}_3 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

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    The unitarity triangles of the 3×33\times 3 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 CPCP-violating decay modes of BdB_{d} and BsB_{s} 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 CPCP 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

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    The top-pions(πt0,±\pi_{t}^{0,\pm}) 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

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    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

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    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 Bs→l+l−B_s\to l^+l^- and B→Kl+l−B\to Kl^+l^- in \the topcolor-assisted technicolor model

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    We examine the rare decays Bs→l+l−B_s\to l^+l^- and B→Kl+l−B\to Kl^+l^- in the framework of the topcolor-assisted technicolor (TC2TC2) 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 Bs→l+l−B_s \to l^+l^- can approach \ord(10^{-2}). The forward-backward asymmetry of leptons in B→Kl+l−B \to Kl^+l^- 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

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    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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