229 research outputs found
The Neutralino Sector of the Next-to-Minimal Supersymmetric Standard Model
The Next-to-Minimal Supersymmetric Standard Model (NMSSM) includes a Higgs
iso-singlet superfield in addition to the two Higgs doublet superfields of the
minimal extension. If the Higgs fields remain weakly coupled up to the GUT
scale, as naturally motivated by the concept of supersymmetry, the mixing
between singlet and doublet fields is small and can be treated perturbatively.
The mass spectrum and mixing matrix of the neutralino sector can be analyzed
analytically and the structure of this 5-state system is under good theoretical
control. We also determine decay modes and production channels in sfermion
cascade decays to these particles at the LHC and pair production in e+e-
colliders.Comment: 27 pages, 8 figure
Dark matter constraints on the parameter space and particle spectra in the nonminimal SUSY standard model
We investigate the dark matter constraints for the nonminimal SUSY standard
model (NMSSM). The cosmologically restricted mass spectra of the NMSSM are
compared to the minimal SUSY standard model (MSSM). The differences of the two
models concerning the neutralino, sfermion and Higgs sector are discussed. The
dark matter condition leads to cosmologically allowed mass ranges for the SUSY
particles in the NMSSM: m_{\tilde{\chi}^0_1} < 300 GeV, m_{\tilde{e}_R} < 300
GeV, 300 GeV < m_{\tilde{u}_R} < 1900 GeV, 200 GeV < m_{\tilde{t}_1} < 1500
GeV, 350 GeV < m_{\tilde{g}} < 2100 GeV and for the mass of the lightest scalar
Higgs m_{S_1} < 140 GeV.Comment: revised version to appear in Phys. Lett. B, 18 pages, LaTeX, 3
figures, uses epsfig.sty and amssymb.st
About direct Dark Matter detection in Next-to-Minimal Supersymmetric Standard Model
Direct dark matter detection is considered in the Next-to-Minimal
Supersymmetric Standard Model (NMSSM). The effective neutralino-quark
Lagrangian is obtained and event rates are calculated for the Ge-73 isotope.
Accelerator and cosmological constraints on the NMSSM parameter space are
included. By means of scanning the parameter space at the Fermi scale we show
that the lightest neutralino could be detected in dark matter experiments with
sizable event rate.Comment: latex, 12 pages, 2 ps-figures; extra LEP constraint is included,
extra figure is added, recorrected version, resubmitted to Phys.Rev.
Tracing the Route of Modern Humans out of Africa by Using 225 Human Genome Sequences from Ethiopians and Egyptians
The predominantly African origin of all modern human populations is well established, but the route taken out of Africa is still unclear. Two alternative routes, via Egypt and Sinai or across the Bab el Mandeb strait into Arabia, have traditionally been proposed as feasible gateways in light of geographic, paleoclimatic, archaeological, and genetic evidence. Distinguishing among these alternatives has been difficult. We generated 225 whole-genome sequences (225 at 8× depth, of which 8 were increased to 30×; Illumina HiSeq 2000) from six modern Northeast African populations (100 Egyptians and five Ethiopian populations each represented by 25 individuals). West Eurasian components were masked out, and the remaining African haplotypes were compared with a panel of sub-Saharan African and non-African genomes. We showed that masked Northeast African haplotypes overall were more similar to non-African haplotypes and more frequently present outside Africa than were any sets of haplotypes derived from a West African population. Furthermore, the masked Egyptian haplotypes showed these properties more markedly than the masked Ethiopian haplotypes, pointing to Egypt as the more likely gateway in the exodus to the rest of the world. Using five Ethiopian and three Egyptian high-coverage masked genomes and the multiple sequentially Markovian coalescent (MSMC) approach, we estimated the genetic split times of Egyptians and Ethiopians from non-African populations at 55,000 and 65,000 years ago, respectively, whereas that of West Africans was estimated to be 75,000 years ago. Both the haplotype and MSMC analyses thus suggest a predominant northern route out of Africa via Egypt
A proposal for a coordinated effort for the determination of brainwide neuroanatomical connectivity in model organisms at a mesoscopic scale
In this era of complete genomes, our knowledge of neuroanatomical circuitry
remains surprisingly sparse. Such knowledge is however critical both for basic
and clinical research into brain function. Here we advocate for a concerted
effort to fill this gap, through systematic, experimental mapping of neural
circuits at a mesoscopic scale of resolution suitable for comprehensive,
brain-wide coverage, using injections of tracers or viral vectors. We detail
the scientific and medical rationale and briefly review existing knowledge and
experimental techniques. We define a set of desiderata, including brain-wide
coverage; validated and extensible experimental techniques suitable for
standardization and automation; centralized, open access data repository;
compatibility with existing resources, and tractability with current
informatics technology. We discuss a hypothetical but tractable plan for mouse,
additional efforts for the macaque, and technique development for human. We
estimate that the mouse connectivity project could be completed within five
years with a comparatively modest budget.Comment: 41 page
QUBE – Quantum Key Distribution with CubeSat
QUBE (Quantum Key Distribution with CubeSat) is one out of three pilot projects in the frame of the national
German initiative QUTEGA to promote quantum technologies. The project is funded by the German Federal Ministry
of Education and Research (BMBF) with co-funding of industry as preparation for the European flagship on Quantum
Technology. With the current development pace in quantum computation, it has been predicted that in less than two
decades quantum computers will be able to break encryption codes deployed today, which are currently based on
mathematical problems difficult to solve with classical computation. This shows the urgent need for quantum-safe
encryption that is resistant to attacks of both, quantum and classical, computers. A long term solution for quantumsafe encryption is the use of a completely random, so-called One-Time-Pad generated with true Random Number
Generation (RNG) and distributed via Quantum Key Distribution (QKD). The QKD in fiber networks is limited to
approx. 100 km due to damping within the carrier medium. For longer distances so far only satellite based techniques
are able to transmit the keys. As a pathfinder, QUBE plans perform an in-orbit demonstration of the core technologies
on a CubeSat platform
The Next-to-Minimal Supersymmetric Standard Model
We review the theoretical and phenomenological aspects of the Next-to-Minimal
Supersymmetric Standard Model: the Higgs sector including radiative corrections
and the 2-loop beta-functions for all parameters of the general NMSSM; the
tadpole and domain wall problems, baryogenesis; NMSSM phenomenology at
colliders, B physics and dark matter; specific scenarios as the constrained
NMSSM, Gauge Mediated Supersymmetry Breaking, U(1)'-extensions, CP and R-parity
violation.Comment: 144 pages, 11 figures, corrections in Eqs.(2.2), (2.21), (B.9
Patterns of somatic structural variation in human cancer genomes.
A key mutational process in cancer is structural variation, in which rearrangements delete, amplify or reorder genomic segments that range in size from kilobases to whole chromosomes1-7. Here we develop methods to group, classify and describe somatic structural variants, using data from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA), which aggregated whole-genome sequencing data from 2,658 cancers across 38 tumour types8. Sixteen signatures of structural variation emerged. Deletions have a multimodal size distribution, assort unevenly across tumour types and patients, are enriched in late-replicating regions and correlate with inversions. Tandem duplications also have a multimodal size distribution, but are enriched in early-replicating regions-as are unbalanced translocations. Replication-based mechanisms of rearrangement generate varied chromosomal structures with low-level copy-number gains and frequent inverted rearrangements. One prominent structure consists of 2-7 templates copied from distinct regions of the genome strung together within one locus. Such cycles of templated insertions correlate with tandem duplications, and-in liver cancer-frequently activate the telomerase gene TERT. A wide variety of rearrangement processes are active in cancer, which generate complex configurations of the genome upon which selection can act
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