LUX-ZEPLIN (LZ) is a dark matter detector expected to obtain world-leading sensitivity to weakly interacting massive particles (WIMPs) interacting via nuclear recoils with a ~7-tonne xenon target ...mass. This manuscript presents sensitivity projections to several low-energy signals of the complementary electron recoil signal type: 1) an effective neutrino magnetic moment and 2) an effective neutrino millicharge, both for pp-chain solar neutrinos, 3) an axion flux generated by the Sun, 4) axion-like particles forming the galactic dark matter, 5) hidden photons, 6) mirror dark matter, and 7) leptophilic dark matter. World-leading sensitivities are expected in each case, a result of the large 5.6t 1000d exposure and low expected rate of electron recoil backgrounds in the \(<\)100keV energy regime. A consistent signal generation, background model and profile-likelihood analysis framework is used throughout.
Two-phase xenon detectors, such as that at the core of the forthcoming LZ dark matter experiment, use photomultiplier tubes to sense the primary (S1) and secondary (S2) scintillation signals ...resulting from particle interactions in their liquid xenon target. This paper describes a simulation study exploring two techniques to lower the energy threshold of LZ to gain sensitivity to low-mass dark matter and astrophysical neutrinos, which will be applicable to other liquid xenon detectors. The energy threshold is determined by the number of detected S1 photons; typically, these must be recorded in three or more photomultiplier channels to avoid dark count coincidences that mimic real signals. To lower this threshold: a) we take advantage of the double photoelectron emission effect, whereby a single vacuum ultraviolet photon has a \(\sim20\%\) probability of ejecting two photoelectrons from a photomultiplier tube photocathode; and b) we drop the requirement of an S1 signal altogether, and use only the ionization signal, which can be detected more efficiently. For both techniques we develop signal and background models for the nominal exposure, and explore accompanying systematic effects, including the dependence on the free electron lifetime in the liquid xenon. When incorporating double photoelectron signals, we predict a factor of \(\sim 4\) sensitivity improvement to the dark matter-nucleon scattering cross-section at \(2.5\) GeV/c\(^2\), and a factor of \(\sim1.6\) increase in the solar \(^8\)B neutrino detection rate. Dropping the S1 requirement may allow sensitivity gains of two orders of magnitude in both cases. Finally, we apply these techniques to even lower masses by taking into account the atomic Migdal effect; this could lower the dark matter particle mass threshold to \(80\) MeV/c\(^2\).
The LUX-ZEPLIN dark matter search aims to achieve a sensitivity to the WIMP-nucleon spin-independent cross-section down to (1--2)\(\times10^{-12}\)\,pb at a WIMP mass of 40 GeV/\(c^2\). This paper ...describes the simulations framework that, along with radioactivity measurements, was used to support this projection, and also to provide mock data for validating reconstruction and analysis software. Of particular note are the event generators, which allow us to model the background radiation, and the detector response physics used in the production of raw signals, which can be converted into digitized waveforms similar to data from the operational detector. Inclusion of the detector response allows us to process simulated data using the same analysis routines as developed to process the experimental data.
Deep underground environments are ideal for low background searches due to the attenuation of cosmic rays by passage through the earth. However, they are affected by backgrounds from \(\gamma\)-rays ...emitted by \(^{40}\)K and the \(^{238}\)U and \(^{232}\)Th decay chains in the surrounding rock. The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a liquid xenon TPC located within the Davis campus at the Sanford Underground Research Facility, Lead, South Dakota, at the 4,850-foot level. In order to characterise the cavern background, in-situ \(\gamma\)-ray measurements were taken with a sodium iodide detector in various locations and with lead shielding. The integral count rates (0--3300~keV) varied from 596~Hz to 1355~Hz for unshielded measurements, corresponding to a total flux in the cavern of \(1.9\pm0.4\)~\(\gamma~\)cm\(^{-2}\)s\(^{-1}\). The resulting activity in the walls of the cavern can be characterised as \(220\pm60\)~Bq/kg of \(^{40}\)K, \(29\pm15\)~Bq/kg of \(^{238}\)U, and \(13\pm3\)~Bq/kg of \(^{232}\)Th.
Phys. Rev. C 102, 014602 (2020) The LUX-ZEPLIN (LZ) experiment will enable a neutrinoless double beta decay
search in parallel to the main science goal of discovering dark matter particle
...interactions. We report the expected LZ sensitivity to $^{136}$Xe neutrinoless
double beta decay, taking advantage of the significant ($>$600 kg) $^{136}$Xe
mass contained within the active volume of LZ without isotopic enrichment.
After 1000 live-days, the median exclusion sensitivity to the half-life of
$^{136}$Xe is projected to be 1.06$\times$10$^{26}$ years (90% confidence
level), similar to existing constraints. We also report the expected
sensitivity of a possible subsequent dedicated exposure using 90% enrichment
with $^{136}$Xe at 1.06$\times$10$^{27}$ years.
Of all the panoramas of nuclear power in the world, none is so disputatious or as pivotal as the issue of nuclear waste and its management. While there is no contiguous reason for alarm, an immense ...amount of amelioration is needed if the worlds custody of its radioactive waste is to become a programmed and prosecuted success. Disposal of waste can highly jeopardize the atmosphere and environment. Already waste disposal in ocean is proscribed by the governments of developed countries. As energy sources are going to be diminished, our future prognoses certainly run towards nuclear power as it is already weighed as a safe and clean alternative energy. As, tralatitious waste disposal system is hazardous, rumination about nuclear waste management, treatment and processing via adopting different physical and chemical technologies is of grave importance. Virility of nuclear waste needs to be controlled and mitigated for safe industrial purposes and fuel consumptions. In this paper, overhauled radioactive waste treatment processes as well as assured data transmission from nuclear power plant to National Load Dispatch Center (NLDC) using digital watermarking is proposed as this type of penetrable data transmission is an affair of cracking concern.
This paper presents a theory of 1.5 factor nonlinear down-sampling, reconstruction and noise elimination. For linear down sampling of two or three factor, one sample is taken and next one or two ...samples are not taken/discarded. Here in non-linear down sampling two or three samples are taken and the next one is not taken. The purpose of this nonlinear down sampling is to send less data samples in voice communication. Though one sample is discarded after taking two samples value of this sample can be reconstructed from values of other samples. Here, two samples are at original sampling period, T s interval and next two samples are at 2T s interval. High-frequency sharp changes were extracted when sampled at T s interval. From received signal, discarded sample can be reconstructed from nearby four samples (Previous two and next two). When original signal contains higher frequency some error signal is introduced, after reconstruction. This error signal depends on original signal. Error signal is eliminated using original signal. Down-sampling is performed after sampling and signal reconstruction is performed just before hearing the sound.
Digital watermarking is the newfangled idea in digital media. As the replication and modification of digital media content is done frequently and without any significant obstruction, secrecy and ...authenticity become vulnerable to attacks. In the information hiding community digital watermarking has achieved immense popularity due to its righteous stronghold against piracy and non-repudiation. Many watermarking algorithm has been developed in recent years. From the context of the purposes, as they serve, they differ from each other. Here we propose some basic algorithms of digital watermarking technique using LSB (Least Significant Bit) and DCT (Discrete Cosine Transformation).
Nowadays internet-based banking is getting popularity because of its several advantages, such as ease of operation and virtual monetary activities, i.e., client's physical presence at different bank ...locations is no more required. However, because of scarcity of accessibility at different locations, cost, and slow speed, number of people using internet communication is a small percentage of the mobile phone users, especially in the developing countries. Moreover, security in internet-based banking is still a major concern. Most of the financial institutions have their own domain and offer web-based transaction facilities. In this paper, we propose a scheme to utilize the internet based existing banking facility via short message service (SMS) available in mobile phone technology without having the internet connection. In view of ensuring a high level of security, we introduce two-level security scheme: voice verification and digital watermarking.
The LUX-ZEPLIN (LZ) experiment will enable a neutrinoless double beta decay search in parallel to the main science goal of discovering dark matter particle interactions. We report the expected LZ ...sensitivity to \(^{136}\)Xe neutrinoless double beta decay, taking advantage of the significant (\(>\)600 kg) \(^{136}\)Xe mass contained within the active volume of LZ without isotopic enrichment. After 1000 live-days, the median exclusion sensitivity to the half-life of \(^{136}\)Xe is projected to be 1.06\(\times\)10\(^{26}\) years (90% confidence level), similar to existing constraints. We also report the expected sensitivity of a possible subsequent dedicated exposure using 90% enrichment with \(^{136}\)Xe at 1.06\(\times\)10\(^{27}\) years.
