8,193 research outputs found
NNMSM Type-II and III
We suggest two types of extension of the standard model, which are the
so-called next to new minimal standard model (NNMSM) type-II and -III. They can
achieve gauge coupling unification as well as suitable dark matter abundance,
small neutrino masses, baryon asymmetry of the universe, inflation, and dark
energy. The gauge coupling unification can be realized by introducing extra two
or three new fields, and could explain the charge quantization. We also show
that there are regions in which the vacuum stability, coupling perturbativity,
and correct dark matter abundance can be realized with current experimental
data at the same time.Comment: 20 pages, 5 figures, comments added. arXiv admin note: substantial
text overlap with arXiv:1309.123
Noncommutative generalizations of theorems of Cohen and Kaplansky
This paper investigates situations where a property of a ring can be tested
on a set of "prime right ideals." Generalizing theorems of Cohen and Kaplansky,
we show that every right ideal of a ring is finitely generated (resp.
principal) iff every "prime right ideal" is finitely generated (resp.
principal), where the phrase "prime right ideal" can be interpreted in one of
many different ways. We also use our methods to show that other properties can
be tested on special sets of right ideals, such as the right artinian property
and various homological properties. Applying these methods, we prove the
following noncommutative generalization of a result of Kaplansky: a (left and
right) noetherian ring is a principal right ideal ring iff all of its maximal
right ideals are principal. A counterexample shows that the left noetherian
hypothesis cannot be dropped. Finally, we compare our results to earlier
generalizations of Cohen's and Kaplansky's theorems in the literature.Comment: 41 pages. To appear in Algebras and Representation Theory. Minor
changes were made to the numbering system, in order to remain consistent with
the published versio
A caseâstudy of coldâair pool evolution in hilly terrain using field measurements from COLPEX
A caseâstudy investigation of coldâair pool (CAP) evolution in hilly terrain is conducted using field measurements made during IOP 16 of the COLdâair Pool EXperiment (COLPEX). COLPEX was designed to study coldâair pooling in smallâscale valleys typical of the UK (âŒ100â200âm deep, âŒ1âkm wide). The synoptic conditions during IOP 16 are typical of those required for CAPs to form during the night, with high pressure, clear skies and low ambient winds. Initially a CAP forms around sunset and grows uninterrupted for several hours. However, starting 4âhr after sunset, a number of interruptions to this steady cooling rate occur. Three episodes are highlighted from the observations and the cause of disruption attributed to (a) wave activity, in the form of gravity waves and/or KelvinâHelmholtz (KH) instability, (b) increases in the aboveâvalley winds resulting from the development of a nocturnal lowâlevel jet (NLLJ), (c) shearâinduced mixing resulting from instability of the NLLJ. A weakly stable residual layer provides the conditions for wave activity during Episode 1. This residual layer is eroded by a developing NLLJ from the top down during Episode 2. The sustained increase in winds at hillâtop levels â attributed to the NLLJ â continue to disrupt the CAP through Episode 3. Although cooling is interrupted, the CAP is never completely eroded during the night. Complete CAP breakâup occurs some 3.5âhr after local sunrise. This caseâstudy highlights a number of meteorological phenomena that can disrupt CAP evolution even in ideal CAP conditions. These processes are unlikely to be sufficiently represented by current operational weather forecast models and can be challenging even for highâresolution research models
Mid- and far-infrared polarimetric studies of the core of OMC-1: the inner field configuration
We present imaging polarimetry of the central 30 arcsec of OMC-1 at 12.5 and 17 ÎŒm with arcsecond resolution, together with complementary spectropolarimetry in the ranges 8â13 and 16â22 ÎŒ ;m at selected positions, and polarimetry at 800 ÎŒm over an approximately 1-arcmin field.
The polarization is due to the dichroism of aligned grains in emission in the farinfrared, and predominantly due to absorption in the mid-infrared. The images reveal large variations of polarization fraction and position angle in BNKL, the central region, and these can explain the low fractional polarization observed when this region is unresolved, as in the far-infrared. The mid-infrared polarization indicates that a substantial component of magnetic field is aligned with the plane of the disc-like structures inferred from millimetre-wave studies, and suggests the presence of a toroidal field within the disc
Novel HSPB1 mutation causes both motor neuronopathy and distal myopathy.
OBJECTIVE: To identify the cause of isolated distal weakness in a family with both neuropathic and myopathic features on EMG and muscle histology. METHODS: Case study with exome sequencing in 2 affected individuals, bioinformatic prioritization of genetic variants, and segregation analysis of the likely causal mutation. Functional studies included Western blot analysis of the candidate protein before and after heat shock treatment of primary skin fibroblasts. RESULTS: A novel HSPB1 variant (c.387C>G, p.Asp129Glu) segregated with the phenotype and was predicted to alter the conserved α-crystallin domain common to small heat shock proteins. At baseline, there was no difference in HSPB1 protein levels nor its binding partner αB-crystallin. Heat shock treatment increased HSPB1 protein levels in both patient-derived and control fibroblasts, but the associated increase in αB-crystallin expression was greater in patient-derived than control fibroblasts. CONCLUSIONS: The HSPB1 variant (c.387C>G, p.Asp129Glu) is the likely cause of distal neuromyopathy in this pedigree with pathogenic effects mediated through binding to its partner heat shock protein αB-crystallin. Mutations in HSBP1 classically cause a motor axonopathy, but this family shows that the distal weakness can be both myopathic and neuropathic. The traditional clinical classification of distal weakness into "myopathic" or "neuropathic" forms may be misleading in some instances, and future treatments need to address the pathology in both tissues.This study was funded by Wellcome Trust (101876/Z/13/Z and 096919Z/11/Z), Medical Research Council (UK) (G0601943), and Medical Research Council Mitochondrial Biology Unit (MC_UP_1501/2). Funding bodies had no influence on study design or data interpretation.This is the final version of the article. It first appeared from Wolters Kluwer via http://dx.doi.org/10.1212/NXG.000000000000011
A Large Scale Double Beta and Dark Matter Experiment: GENIUS
The recent results from the HEIDELBERG-MOSCOW experiment have demonstrated
the large potential of double beta decay to search for new physics beyond the
Standard Model. To increase by a major step the present sensitivity for double
beta decay and dark matter search much bigger source strengths and much lower
backgrounds are needed than used in experiments under operation at present or
under construction. We present here a study of a project proposed recently,
which would operate one ton of 'naked' enriched GErmanium-detectors in liquid
NItrogen as shielding in an Underground Setup (GENIUS). It improves the
sensitivity to neutrino masses to 0.01 eV. A ten ton version would probe
neutrino masses even down to 10^-3 eV. The first version would allow to test
the atmospheric neutrino problem, the second at least part of the solar
neutrino problem. Both versions would allow in addition significant
contributions to testing several classes of GUT models. These are especially
tests of R-parity breaking supersymmetry models, leptoquark masses and
mechanism and right-handed W-boson masses comparable to LHC. The second issue
of the experiment is the search for dark matter in the universe. The entire
MSSM parameter space for prediction of neutralinos as dark matter particles
could be covered already in a first step of the full experiment - with the same
purity requirements but using only 100 kg of 76Ge or even of natural Ge -
making the experiment competitive to LHC in the search for supersymmetry.
The layout of the proposed experiment is discussed and the shielding and
purity requirements are studied using GEANT Monte Carlo simulations. As a
demonstration of the feasibility of the experiment first results of operating a
'naked' Ge detector in liquid nitrogen are presented.Comment: 22 pages, 12 figures, see also
http://pluto.mpi-hd.mpg.de/~betalit/genius.htm
The Rydberg-Atom-Cavity Axion Search
We report on the present progress in development of the dark matter axion
search experiment with Rydberg-atom-cavity detectors in Kyoto, CARRACK I and
CARRACK II. The axion search has been performed with CARRACK I in the 8 % mass
range around , and CARRACK II is now ready for the search in
the wide range . We have also developed
quantum theoretical calculations on the axion-photon-atom system in the
resonant cavity in order to estimate precisely the detection sensitivity for
the axion signal. Some essential features on the axion-photon-atom interaction
are clarified, which provide the optimum experimental setup for the axion
search.Comment: 8 pages, 2 figures, Invited talk presented at the Dark2000,
Heidelberg, Germany,10-15 July, 200
Vectorlike Confinement at the LHC
We argue for the plausibility of a broad class of vectorlike confining gauge
theories at the TeV scale which interact with the Standard Model predominantly
via gauge interactions. These theories have a rich phenomenology at the LHC if
confinement occurs at the TeV scale, while ensuring negligible impact on
precision electroweak and flavor observables. Spin-1 bound states can be
resonantly produced via their mixing with Standard Model gauge bosons. The
resonances promptly decay to pseudo-Goldstone bosons, some of which promptly
decay to a pair of Standard Model gauge bosons, while others are charged and
stable on collider time scales. The diverse set of final states with little
background include multiple photons and leptons, missing energy, massive stable
charged particles and the possibility of highly displaced vertices in dilepton,
leptoquark or diquark decays. Among others, a novel experimental signature of
resonance reconstruction out of massive stable charged particles is
highlighted. Some of the long-lived states also constitute Dark Matter
candidates.Comment: 33 pages, 6 figures. v4: expanded discussion of Z_2 symmetry for
stability, one reference adde
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