17 research outputs found
Preparation of Neutron-activated Xenon for Liquid Xenon Detector Calibration
We report the preparation of neutron-activated xenon for the calibration of
liquid xenon (LXe) detectors. Gamma rays from the decay of xenon metastable
states, produced by fast neutron activation, were detected and their activities
measured in a LXe scintillation detector. Following a five-day activation of
natural xenon gas with a Cf-252 (4 x 10^5 n/s) source, the activities of two
gamma ray lines at 164 keV and 236 keV, from Xe-131m and Xe-129m metastable
states, were measured at about 95 and 130 Bq/kg, respectively. We also observed
three additional lines at 35 keV, 100 keV and 275 keV, which decay away within
a few days. No long-lifetime activity was observed after the neutron
activation.Comment: to be published in NIM A, corrected typos in Table 1 and Fig.6 of the
previous versio
Domain walls of N=2 supergravity in five dimensions from hypermultiplet moduli spaces
We study domain wall solutions in d=5, N=2 supergravity coupled to a single
hypermultiplet whose moduli space is described by certain inhomogeneous, toric
ESD manifolds constructed recently by Calderbank and Singer. Upon gauging a
generic U(1) isometry of these spaces, we obtain an infinite family of models
whose "superpotential" admits an arbitrary number of isolated critical points.
By investigating the associated supersymmetric flows, we prove the existence of
domain walls of Randall-Sundrum type for each member of our family, and find
chains of domain walls interpolating between various AdS_5 backgrounds. Our
models are described by a discrete infinity of smooth and complete
one-hypermultiplet moduli spaces, which live on an open subset of the minimal
resolution of certain cyclic quotient singularities. These spaces generalize
the Pedersen metrics considered recently by Behrndt and Dall' Agata.Comment: 39 pages, numerous figures; v4: two references adde
Study of KS KL Coupled Decays and KL -Be Interactions with the CMD-2 Detector at VEPP-2M Collider
The integrated luminosity about 4000 inverse nanobarn of around phi meson
mass ( 5 millions of phi mesons) has been collected with the CMD-2 detector at
the VEPP-2M collider. A latest analysis of the KS KL coupled decays based on 30
% of available data is presented in this paper.
The KS KL pairs from phi meson decays were reconstructed in the drift chamber
when both kaons decayed into two charged particles. From a sample of 1423
coupled decays a selection of candidates to the CP violating KL into pi+ pi-
decay was performed. CP violating decays were not identified because of the
domination of events with a KL regenerating at the Be beam pipe into KS and a
background from KL semileptonic decays.
The regeneration cross section of 110 MeV/c KL mesons was found to be 53 +-
17 mb in agreement with theoretical expectations. The angular distribution of
KS mesons after regeneration and the total cross section of KL for Be have been
measured.Comment: 14 pages, 8 figure
Recent advances in neutrinoless double beta decay search
Even after the discovery of neutrino flavour oscillations, based on data from
atmospheric, solar, reactor, and accelerator experiments, many characteristics
of the neutrino remain unknown. Only the neutrino square-mass differences and
the mixing angle values have been estimated, while the value of each mass
eigenstate still hasn't. Its nature (massive Majorana or Dirac particle) is
still escaping. Neutrinoless double beta decay (-DBD) experimental
discovery could be the ultimate answer to some delicate questions of elementary
particle and nuclear physics. The Majorana description of neutrinos allows the
-DBD process, and consequently either a mass value could be measured or
the existence of physics beyond the standard should be confirmed without any
doubt. As expected, the -DBD measurement is a very difficult field of
application for experimentalists. In this paper, after a short summary of the
latest results in neutrino physics, the experimental status, the R&D projects,
and perspectives in -DBD sector are reviewed.Comment: 36 pages, 7 figures, To be publish in Czech Journal of Physic
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Beam Physics of Integrable Optics Test Accelerator at Fermilab
Fermilab's Integrable Optics Test Accelerator (IOTA) is an electron storage ring designed for testing advanced accelerator physics concepts, including implementation of nonlinear integrable beam optics and experiments on optical stochastic cooling. The machine is currently under construction at the Advanced Superconducting Test Accelerator facility. In this report we present the goals and the current status of the project, and describe the details of machine design. In particular, we concentrate on numerical simulations setting the requirements on the design and supporting the choice of machine parameters
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Design and Simulation of IOTA - a Novel Concept of Integrable Optics Test Accelerator
The use of nonlinear lattices with large betatron tune spreads can increase instability and space charge thresholds due to improved Landau damping. Unfortunately, the majority of nonlinear accelerator lattices turn out to be nonintegrable, producing chaotic motion and a complex network of stable and unstable resonances. Recent advances in finding the integrable nonlinear accelerator lattices have led to a proposal to construct at Fermilab a test accelerator with strong nonlinear focusing which avoids resonances and chaotic particle motion. This presentation will outline the main challenges, theoretical design solutions and construction status of the Integrable Optics Test Accelerator (IOTA) underway at Fermilab