1,389 research outputs found
Grand unification through gravitational effects
We systematically study the unification of gauge couplings in the presence of
(one or more) effective dimension-5 operators cHGG/4MPl, induced into the grand
unified theory by gravitational interactions at the Planck scale MPl. These
operators alter the usual condition for gauge coupling unification, which can,
depending on the Higgs content H and vacuum expectation value, result in
unification at scales MX significantly different than naively expected. We find
non-supersymmetric models of SU(5) and SO(10) unification, with natural Wilson
coefficients c, that easily satisfy the constraints from proton decay.
Furthermore, gauge coupling unification at scales as high as the Planck scale
seems feasible, possibly hinting at simultaneous unification of gauge and
gravitational interactions. In the Appendix we work out the group theoretical
aspects of this scenario for SU(5) and SO(10) unified groups in detail; this
material is also relevant in the analysis of non-universal gaugino masses
obtained from supergravity.Comment: 27 pages, 5 figures, 8 tables, 1 appendix, revtex; v2: introduction
and conclusion expanded, references added, minor changes, version published
in PR
InP solid state detector and the observation of low energy solar neutrinos
A large volume radiation detectors using a semi-insulating Indium Phosphide (InP) wafer have been developed for Indium Project on Neutrino Observation for Solar interior (IPNOS) experiment. The volume has achieved to 20mm3 , and this is world largest size among the detector observed gammas at hundred keV region. Although the depletion layer, most of charge are generated by an induction, and the charge collection efficiency achieves 50 to 60%, which is determined by the detector thickness and the carrier drift length (Ld = 120μm). The energy resolution is obtained by 25%. We measured actual backgrounds from 115 In beta decay, and also the effect of radiative Bremsstrahlung from those betas. No significant event was found in the measurement and the radiation such as Bremsstrahlung from InP detector could be negligible
Perturbative SO(10) Grand Unification
We consider a phenomenologically viable SO(10) grand unification model of the
unification scale around GeV which reproduces the MSSM at low
energy and allows perturbative calculations up to the Planck scale or the
string scale . Both requirements strongly restrict a choice of Higgs
representations in a model. We propose a simple SO(10) model with a set of
Higgs representations and show its phenomenological viability. This model can indeed
reproduce the low-energy experimental data relating the charged fermion masses
and mixings. Neutrino oscillation data can be consistently incorporated in the
model, leading to the right-handed neutrino mass scale .
Furthermore, there exists a parameter region which results the proton life time
consistent with the experimental results.Comment: 14 pages, no figure, section5 was slightly modifie
Tight--binding description of the quasiparticle dispersion of graphite and few--layer graphene
A universal set of third--nearest neighbour tight--binding (TB) parameters is
presented for calculation of the quasiparticle (QP) dispersion of stacked
graphene layers () with stacking sequence. The QP
bands are strongly renormalized by electron--electron interactions which
results in a 20% increase of the nearest neighbour in--plane and out--of--plane
TB parameters when compared to band structure from density functional theory.
With the new set of TB parameters we determine the Fermi surface and evaluate
exciton energies, charge carrier plasmon frequencies and the conductivities
which are relevant for recent angle--resolved photoemission, optical, electron
energy loss and transport measurements. A comparision of these quantitities to
experiments yields an excellent agreement. Furthermore we discuss the
transition from few layer graphene to graphite and a semimetal to metal
transition in a TB framework.Comment: Corresponding author: A. Gr\"uneis Tel.: +49 351 4659 519 e--mail:
[email protected]
Fine-tuning the functional properties of carbon nanotubes via the interconversion of encapsulated molecules
Tweaking the properties of carbon nanotubes is a prerequisite for their
practical applications. Here we demonstrate fine-tuning the electronic
properties of single-wall carbon nanotubes via filling with ferrocene
molecules. The evolution of the bonding and charge transfer within the tube is
demonstrated via chemical reaction of the ferrocene filler ending up as
secondary inner tube. The charge transfer nature is interpreted well within
density functional theory. This work gives the first direct observation of a
fine-tuned continuous amphoteric doping of single-wall carbon nanotubes
Lattice QCD calculation of the proton decay matrix element in the continuum limit
We present a quenched lattice QCD calculation of the \alpha and \beta
parameters of the proton decay matrix element. The simulation is carried out
using the Wilson quark action at three values of the lattice spacing in the
range a\approx 0.1-0.064 fm to study the scaling violation effect. We find only
mild scaling violation when the lattice scale is determined by the nucleon
mass. We obtain in the continuum limit,
|\alpha(NDR,2GeV)|=0.0090(09)(^{+5}_{-19})GeV^3 and
|\beta(NDR,2GeV)|=0.0096(09)(^{+6}_{-20})GeV^3 with \alpha and \beta in a
relatively opposite sign, where the first error is statistical and the second
is due to the uncertainty in the determination of the physical scale.Comment: 4 pages, 3 figure
Clinical efficacy of long-acting neuraminidase inhibitor, laninamivir octanoate hydrate, in postmarketing surveillance
Continuation of Methotrexate Resulted in Better Clinical and Radiographic Outcomes Than Discontinuation upon Starting Etanercept in Patients with Rheumatoid Arthritis: 52-week Results from the JESMR Study
ABSTRACT. Objective. The aim of the Efficacy and Safety of Etanercept on Active Rheumatoid Arthritis Despite Methotrexate Therapy in Japan (JESMR) study is to compare the efficacy of continuation versus discontinuation of methotrexate (MTX) when starting etanercept (ETN) in patients with active rheumatoid arthritis (RA). Methods. In total, 151 patients with active RA who had been taking MTX were randomized to either ETN 25 mg twice a week with 6-8 mg/week MTX (the E+M group), or ETN alone (the E group). The primary endpoint at Week 52 was the radiographic progression assessed by van der Heijde-modified Sharp score. Results. The mean progression in total score at Week 52 was not significantly different, statistically, between the E+M group and the E group (0.8 vs 3.6, respectively; p = 0.06). However, a significant difference was observed in radiographic progression between Weeks 24 and 52 (0.3 vs 2.5; p = 0.03), and the mean progression of the erosion score was negative in the E+M group, which was significantly better than the E group at Week 52 (-0.2 vs 1.8; p = 0.02). Clinically, the cumulative probability plot of the American College of Rheumatology (ACR)-N values at Week 52 clearly demonstrated a superior response in the E+M group than in the E group. ACR20, 50, and 70 response rates at Week 52 in the E+M group (86.3%, 76.7%, and 50.7%) were significantly greater than those in the E group (63.8%; p = 0.003, 43.5%; p < 0.0001 and 29.0%; p = 0.01, respectively). Conclusion. MTX should be continued when starting ETN in patients with active RA
MTX and ETN Personal non-commercial use only
ABSTRACT. Objective. The aim of the Efficacy and Safety of Etanercept on Active Rheumatoid Arthritis Despite Methotrexate Therapy in Japan (JESMR) study is to compare the efficacy of continuation versus discontinuation of methotrexate (MTX) when starting etanercept (ETN) in patients with active rheumatoid arthritis (RA). Methods. In total, 151 patients with active RA who had been taking MTX were randomized to either ETN 25 mg twice a week with 6-8 mg/week MTX (the E+M group), or ETN alone (the E group). The primary endpoint at Week 52 was the radiographic progression assessed by van der Heijde-modified Sharp score. Results. The mean progression in total score at Week 52 was not significantly different, statistically, between the E+M group and the E group (0.8 vs 3.6, respectively; p = 0.06). However, a significant difference was observed in radiographic progression between Weeks 24 and 52 (0.3 vs 2.5; p = 0.03), and the mean progression of the erosion score was negative in the E+M group, which was significantly better than the E group at Week 52 (-0.2 vs 1.8; p = 0.02). Clinically, the cumulative probability plot of the American College of Rheumatology (ACR)-N values at Week 52 clearly demonstrated a superior response in the E+M group than in the E group. ACR20, 50, and 70 response rates at Week 52 in the E+M group (86.3%, 76.7%, and 50.7%) were significantly greater than those in the E group (63.8%; p = 0.003, 43.5%; p < 0.0001 and 29.0%; p = 0.01, respectively). Conclusion. MTX should be continued when starting ETN in patients with active RA
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