12,617 research outputs found
The young cluster NGC 2282 : a multi-wavelength perspective
We present the analysis of the stellar content of NGC~2282, a young cluster
in the Monoceros constellation, using deep optical and IPHAS photometry
along with infrared (IR) data from UKIDSS and -IRAC. Based on the
stellar surface density analysis using nearest neighborhood method, the radius
of the cluster is estimated as 3.15\arcmin. From optical spectroscopic
analysis of 8 bright sources, we have classified three early B-type members in
the cluster, which includes, HD 289120, a previously known B2V type star, a
Herbig Ae/Be star (B0.5 Ve) and a B5 V star. From spectrophotometric analyses,
the distance to the cluster has been estimated as 1.65 kpc. The -band
extinction map is estimated using nearest neighborhood technique, and the mean
extinction within the cluster area is found to be A 3.9 mag. Using
IR colour-colour criteria and H-emission properties, we have
identified a total of 152 candidate young stellar objects (YSOs) in the region,
of which, 75 are classified as Class II, 9 are Class I YSOs. Our YSO catalog
also includes 50 H-emission line sources, identified using slitless
spectroscopy and IPHAS photometry data. Based on the optical and near-IR
colour-magnitude diagram analyses, the cluster age has been estimated to be in
the range of 2 5 Myr, which is in agreement with the estimated age from
disc fraction ( 58\%). Masses of these YSOs are found to be
0.12.0 M. Spatial distribution of the candidate YSOs shows spherical
morphology, more or less similar to the surface density map.Comment: 16 pages, 19 Figure
Nuclear effects in Neutrino Nuclear Cross-sections
Nuclear effects in the quasielastic and inelastic scattering of
neutrinos(antineutrinos) from nuclear targets have been studied. The
calculations are done in the local density approximation which take into
account the effect of nucleon motion as well as renormalisation of weak
transition strengths in the nuclear medium. The inelastic reaction leading to
production of pions is calculated in a dominance model taking into
account the renormalization of properties in the nuclear medium.Comment: 4 pages,3 figures, Ninth International Workshop on Neutrino
Factories, Superbeams and Betabeams (NuFact07), August 6-11, 2007, Okayama
University, Okayama, Japa
A robot design for wind generator support structure inspection
In recent time, the development of wind tower inspection has been very crucial for the overall performance of the wind turbine. In order to maintain, monitor and determine the life span of the tower, an investigation of robot design is discussed. It presents how to design and construct a robot that can climb the tower and rotate 360° . A ring system which is in a circular shape robot is designed that allows the device to fit in the structure of the wind generator tower. The rotational module is designed to allow the wheels to rotate and be able to go in a circular motion. Also it is designed with a suspension that allows the robot to go through any obstacle. This paper also presents the FEA spring stress analysis and Simulink control system model to find the optimal parameters that are required for the wind tower climbing robot
Global NLO Analysis of Nuclear Parton Distribution Functions
Nuclear parton distribution functions (NPDFs) are determined by a global
analysis of experimental measurements on structure-function ratios
F_2^A/F_2^{A'} and Drell-Yan cross section ratios
\sigma_{DY}^A/\sigma_{DY}^{A'}, and their uncertainties are estimated by the
Hessian method. The NPDFs are obtained in both leading order (LO) and
next-to-leading order (NLO) of \alpha_s. As a result, valence-quark
distributions are relatively well determined, whereas antiquark distributions
at x>0.2 and gluon distributions in the whole x region have large
uncertainties. The NLO uncertainties are slightly smaller than the LO ones;
however, such a NLO improvement is not as significant as the nucleonic case.Comment: 3 pages, LaTeX, 4 eps files, to be published in the AIP proceedings
of the 9th International Workshop on Neutrino Factories, Superbeams and
Betabeams (NuFact07), Okayama, Japan, August 6 - 11, 2007. A code for
calculating our nuclear parton distribution functions and their uncertainties
can be obtained from http://research.kek.jp/people/kumanos/nuclp.htm
Limits on monopole fluxes from KFG experiment
The nucleon decay experiment at KGF at a depth of 2.3 Km is eminently suited for the search of Grand Unified theory (GUT) monopoles, whose velocities at the present epoch are predicted to be around 0.001C. At this depth the cosmic ray background is at a level 2/day in the detector of size 4m x 6m x 3.7m and one can look for monopoles traversing the detector in all directions, using three methods, i.e., (1) dE/dx (ionization); (2) time of flight and (3) catalysis of nucleon decay. The detector is composed of 34 layers of proportional counters arranged in horizontal planes one above the other in an orthogonal maxtrix. Each of the 1594 counters are instrumented to measure ionization in the gas (90% Argon + 10% Methane) as well as the time of arrival of particles
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Explaining a CMS eejj excess with R -parity violating supersymmetry and implications for neutrinoless double beta decay
A recent CMS search for the right handed gauge boson reports an
interesting deviation from the Standard Model. The search has been conducted in
the channel and has shown a 2.8 excess around
TeV. In this work, we explain the reported CMS excess with R-parity violating
supersymmetry (SUSY). We consider resonant selectron and sneutrino production,
followed by the three body decays of the neutralino and chargino via an
parity violating coupling. We fit the excess for slepton masses
around 2 TeV. The scenario can further be tested in neutrinoless double beta
decay () experiments. GERDA Phase-II will probe a significant
portion of the good-fit parameter space.This work has been partially supported by STFC. MM acknowledges partial support of the ITN INVISIBLES (Marie Curie Actions, PITN-GA-2011-289442).This is the accepted manuscript. The final version is available from APS at http://journals.aps.org/prd/abstract/10.1103/PhysRevD.91.01170
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Resonant slepton production yields CMS eejj and e p Tjj excesses
Recent CMS searches for di-leptoquark production report local excesses of
2.4 in a channel and 2.6 in a missing
channel. Here, we simultaneously explain both excesses with resonant slepton
production in parity violating supersymmetry (SUSY). We consider
resonant slepton production, which decays to a lepton and a
chargino/neutralino, followed by three-body decays of the neutralino/chargino
via an parity violating coupling. There are regions of parameter
space which are also compatible at the 95% confidence level (CL) with a
2.8 excess in a recent CMS search, while being compatible
with other direct search constraints. Phase-II of the GERDA neutrinoless double
beta decay () experiment will probe a sizeable portion of the
good-fit region.This work has been partially supported by STFC. We thank the Cambridge SUSY working group for stimulating discussions. M. M. acknowledges partial support of the ITN INVISIBLES (Marie Curie Actions, PITN-GA-2011-289442).This is the accepted version. The final version is available from APS at http://journals.aps.org/prd/abstract/10.1103/PhysRevD.91.015011
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