383 research outputs found
Direct observation of 4+ to 2+ gamma transition in 8Be
The low lying states in Be are believed to have a two-alpha cluster
structure and hence a large intrinsic quadrupole deformation. An earlier
calculation showed a large collective enhancement in gamma transition
probability between the low lying states leading to a 4 to 2 gamma
branch of and a resonant radiative cross section of 134 nb for
the entrance channel. We report here the first experimental
evidence for this transition through a coincidence
measurement in the reaction He()He using a gas
target. The measured cross sections on and off the 4 resonance are 165
41 (stat) 35 (sys) nb and 39 25 (stat) 7 (sys) nb,
respectively.Comment: Total 4 pages, 4 figures, in RevTeX format, submitted to PR
On the classification of Kahler-Ricci solitons on Gorenstein del Pezzo surfaces
We give a classification of all pairs (X,v) of Gorenstein del Pezzo surfaces
X and vector fields v which are K-stable in the sense of Berman-Nystrom and
therefore are expected to admit a Kahler-Ricci solition. Moreover, we provide
some new examples of Fano threefolds admitting a Kahler-Ricci soliton.Comment: 21 pages, ancillary files containing calculations in SageMath; minor
correction
Microfilaria in malignant pleural effusion: an unusual incidental finding or causative association?
Lymphatic filariasis is common in tropical countries and is endemic in India. Filaria has a wide spectrum of presentation. Filarial lung involvement is usually in the form of tropical pulmonary eosinophilia with pulmonary infiltrates and peripheral eosinophilia. Filariasis presenting with pleural effusion is an unusual presentation. Malignancy in association with filarial pleural effusion is extremely rare and its role in tumorigenesis is controversial. In this context, we hereby report a case of 60 year old male, chronic smoker, who presented with left sided chest pain, cough, breathlessness, generalized weakness and swelling over left infrascapular region. Pleural fluid cytology repeated thrice due to degenerative changes, finally revealed malignant cells along with microfilaria. FNAC from left infrascapular swelling showed cytological features suggestive of metastatic deposits of Adenocarcinoma
Improving Time and Position Resolution of RPC detectors using Time Over Threshold Information
INO-ICAL is a proposed underground particle physics experiment to study the
neutrino oscillation parameters by detecting neutrinos produced in the
atmospheric air showers. Iron CALorimeter (ICAL) is to have 151 layers of iron
stacked vertically, with active detector elements in between the iron layers.
The iron layers will be magnetized to enable the measurement of momentum and
charge of the (or ) produced by (or )
interactions. Resistive Plate Chambers (RPCs) have been chosen as the active
detector elements due to their large area coverage, uncompromised sensitivity,
consistent performance for decades, as well as cost effectiveness. The major
factors that decide the physics potential of the ICAL experiment are
efficiency, position resolution and time resolution of the large area RPCs. A
prototype detector called miniICAL (with 11 iron layers) was commissioned to
understand the engineering challenges in building the large scale magnet and
its ancillary systems, and also to study the performance of the RPC detectors
and readout electronics developed by the INO collaboration. As part of the
performance study of the RPC detectors, an attempt is made to improve the
position and time resolution of them. Even a small improvement in the position
and time resolution will help to improve the measurements of momentum and
directionality of the neutrinos in ICAL. The Time-over-Threshold (ToT) of the
RPC pulses (signals) is recorded by the readout electronics. ToT is a measure
of the pulse width and consequently the amplitude. This information is used to
improve the time and position resolution of the RPCs and consequently INO
physics potential
Astrophysical S_{17}(0) factor from a measurement of d(7Be,8B)n reaction at E_{c.m.} = 4.5 MeV
Angular distribution measurements of H(Be,Be)H and
H(Be,B) reactions at ~4.5 MeV were performed to
extract the astrophysical factor using the asymptotic normalization
coefficient (ANC) method. For this purpose a pure, low emittance Be beam
was separated from the primary Li beam by a recoil mass spectrometer
operated in a novel mode. A beam stopper at 0 allowed the use of a
higher Be beam intensity. Measurement of the elastic scattering in the
entrance channel using kinematic coincidence, facilitated the determination of
the optical model parameters needed for the analysis of the transfer data. The
present measurement significantly reduces errors in the extracted
Be(p,) cross section using the ANC method. We get
~(0)~=~20.7~~2.4 eV~b.Comment: 15 pages including 3 eps figures, one figure removed and discussions
updated. Version to appear in Physical Review
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