81 research outputs found
No scale SUGRA SO(10) derived Starobinsky Model of Inflation
We show that a supersymmetric renormalizable theory based on gauge group
SO(10) and Higgs system {\bf {10 210 126
}} with no scale supergravity can lead to a Starobinsky
kind of potential for inflation. Successful inflation is possible in the cases
where the potential during inflation corresponds to , and flipped intermediate symmetry with a suitable choice of superpotential
parameters. The reheating in such a scenario can occur via non perturbative
decay of inflaton i.e. through "preheating". After the end of reheating, when
universe cools down, the finite temperature potential can have a minimum which
corresponds to MSSM.Comment: 6 pages, 2 figures, Replaced with version to appear in Phys Lett
NMSGUT emergence and Trans-Unification RG flows
Consistency of trans-unification RG evolution is used to discuss the domain
of definition of the New Minimal Supersymmetric SO(10) GUT (NMSGUT). We compute
the 1-loop RGE functions, simplifying generic formulae using
constraints of gauge invariance and superpotential structure. We also calculate
the 2 loop contributions to the gauge coupling and gaugino mass and indicate
how to get full 2 loop results for all couplings. Our method overcomes
combinatorial barriers that frustrate computer algebra based attempts to
calculate SO(10) functions involving large irreps. Use of the RGEs
identifies a perturbative domain , where is the
\emph{scale of emergence} where the NMSGUT, with GUT compatible soft
supersymmetry breaking terms emerges from the strong UV dynamics associated
with the Landau poles in gauge and Yukawa couplings. Due to the strength of the
RG flows the Landau poles for gauge and Yukawa couplings lie near a cutoff
scale for the perturbative dynamics of the NMSGUT which just above
. SO(10) RG flows into the IR are shown to facilitate small gaugino masses
and generation of negative Non Universal Higgs masses squared needed by
realistic NMSGUT fits of low energy data. Running the simple canonical theory
emergent at through down to the electroweak scale enables tests of
candidate scenarios such as supergravity based NMSGUT with canonical kinetic
terms and NMSGUT based dynamical Yukawa unification.Comment: 36 pages, 1 Figure, 4 Tables, 77 equations, 42 references, RevTeX4
PDFLateX. Version published in Phys. Rev.
Baryon Stability on the Higgs Dissolution Edge : Threshold corrections and suppression of Baryon violation in the NMSGUT
Superheavy threshold corrections to the matching condition between matter
Yukawa couplings of the effective Minimal Supersymmetric Standard Model (MSSM)
and the New Minimal Supersymmetric (SO(10)) GUT(NMSGUT) provide a novel and
generic mechanism for reducing the long standing and generically problematic
operator dimension 5 Baryon decay rates. In suitable regions of the parameter
space strong wave function renormalization of the effective MSSM Higgs doublets
due to the large number of heavy fields can take the wave function
renormalization of the MSSM Higgs field close to the dissolution value
(). Rescaling to canonical kinetic terms lowers the
SO(10) Yukawas required to match the MSSM fermion data. Since the same Yukawas
determine the dimension 5 B violation operator coefficients, the associated
rates can be suppressed to levels compatible with current limits. Including
these threshold effects also relaxes the constraint operative between plet generated tree
level MSSM matter fermion Yukawas . We exhibit accurate fits of the MSSM
fermion mass-mixing data in terms of NMSGUT superpotential couplings and 5
independent soft Susy breaking parameters specified at GeV with
the claimed suppression of Baryon decay rates. As before, our s-spectra are of
the mini split supersymmetry type with large TeV, light gauginos and normal s-hierarchy. Large and soft
masses allow significant deviation from the canonical GUT gaugino mass ratios
and ensure vacuum safety. Even without optimization, prominent candidates for
BSM discovery such as the muon magnetic anomaly, and
Lepto-genesis CP violation emerge in the preferred ball park.Comment: PdfLatex. 50 pages. Version accepted for publication in Nuclear
Phys.B(2014). Available online at
http://dx.doi.org/10.1016/j.nuclphysb.2014.03.003. arXiv admin note:
substantial text overlap with arXiv:1107.296
Origin of Shifts in the Surface Plasmon Resonance Frequencies for Au and Ag Nanoparticles
Origin of shifts in the surface plasmon resonance (SPR) frequency for noble
metal (Au, Ag) nanoclusters are discussed in this book chapter. Spill out of
electron from the Fermi surface is considered as the origin of red shift. On
the other hand, both screening of electrons of the noble metal in porous media
and quantum effect of screen surface electron are considered for the observed
blue shift in the SPR peak position.Comment: 37 pages, 14 Figures in the submitted book chapter of The Annual
Reviews in Plasmonics, edited by Professor Chris D. Geddes. Springer Scinec
c-Jun N-Terminal Kinase 1 Is Required for Toll-Like Receptor 1 Gene Expression in Macrophages
P. 5027-5034The regulation of innate immune responses to pathogens occurs through the interaction of Toll-like receptors
(TLRs) with pathogen-associated molecular patterns and the activation of several signaling pathways
whose contribution to the overall innate immune response to pathogens is poorly understood. We demonstrate
a mechanism of control of murine macrophage responses mediated by TLR1/2 heterodimers through c-Jun
N-terminal kinase 1 (JNK1) activity. JNK controls tumor necrosis factor alpha production and TLR-mediated
macrophage responses to Borrelia burgdorferi, the causative agent of Lyme disease, and the TLR1/TLR2-specific
agonist PAM3CSK4. JNK1, but not JNK2, activity regulates the expression of the tlr1 gene in the macrophage
cell line RAW264.7, as well as in primary CD11b cells. We also show that the proximal promoter region of
the human tlr1 gene contains an AP-1 binding site that is subjected to regulation by the kinase and binds two
complexes that involve the JNK substrates c-Jun, JunD, and ATF-2. These results demonstrate that JNK1
regulates the response to TLR1/2 ligands and suggest a positive feedback loop that may serve to increase the
innate immune response to the spirocheteS
Cancer metabolism: current perspectives and future directions
Cellular metabolism influences life and death decisions. An emerging theme in cancer biology is that metabolic regulation is intricately linked to cancer progression. In part, this is due to the fact that proliferation is tightly regulated by availability of nutrients. Mitogenic signals promote nutrient uptake and synthesis of DNA, RNA, proteins and lipids. Therefore, it seems straight-forward that oncogenes, that often promote proliferation, also promote metabolic changes. In this review we summarize our current understanding of how ‘metabolic transformation' is linked to oncogenic transformation, and why inhibition of metabolism may prove a cancer′s ‘Achilles' heel'. On one hand, mutation of metabolic enzymes and metabolic stress sensors confers synthetic lethality with inhibitors of metabolism. On the other hand, hyperactivation of oncogenic pathways makes tumors more susceptible to metabolic inhibition. Conversely, an adequate nutrient supply and active metabolism regulates Bcl-2 family proteins and inhibits susceptibility to apoptosis. Here, we provide an overview of the metabolic pathways that represent anti-cancer targets and the cell death pathways engaged by metabolic inhibitors. Additionally, we will detail the similarities between metabolism of cancer cells and metabolism of proliferating cells
Electroweak vacuum stability in presence of singlet scalar dark matter in TeV scale seesaw models
We consider singlet extensions of the standard model, both in the fermion and the scalar sector, to account for the generation of neutrino mass at the TeV scale and the existence of dark matter respectively. For the neutrino sector we consider models with extra singlet fermions which can generate neutrino mass via the so called inverse or linear seesaw mechanism whereas a singlet scalar is introduced as the candidate for dark matter. We show that although these two sectors are disconnected at low energy, the coupling constants of both the sectors get correlated at high energy scale by the constraints coming from the perturbativity and stability/metastability of the electroweak vacuum. The singlet fermions try to destabilize the electroweak vacuum while the singlet scalar aids the stability. As an upshot, the electroweak vacuum may attain absolute stability even upto the Planck scale for suitable values of the parameters. We delineate the parameter space for the singlet fermion and the scalar couplings for which the electroweak vacuum remains stable/metastable and at the same time giving the correct relic density and neutrino masses and mixing angles as observed.by Ila Garg, Srubabati Goswami, Vishnudath K. N. and Najimuddin Kha
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