scholarly journals A 500 MS/s waveform digitizer for PandaX dark matter experiments

2021 ◽  
Vol 16 (12) ◽  
pp. T12015
Author(s):  
C. He ◽  
J. Liu ◽  
X. Ren ◽  
X. Shang ◽  
X. Wei ◽  
...  
Keyword(s):  
Dark Matter ◽  
System Performance ◽  
Particle Physics ◽  
Sampling Rate ◽  
Real Data ◽  
Full Waveform ◽  
Low Threshold ◽  
Physics Experiments ◽  
Low Rate

Abstract Waveform digitizers are key readout instruments in particle physics experiments. In this paper, we present a waveform digitizer for the PandaX dark matter experiments. It supports both external-trigger readout and triggerless readout, accommodating the needs of low rate full-waveform readout and channel-independent low threshold acquisition, respectively. This digitizer is a 8-channel VME board with a sampling rate of 500 MS/s and 14-bit resolution for each channel. A digitizer system consisting of 72 channels has been tested in situ of the PandaX-4T experiment. We report the system performance with real data.

scholarly journals PROBING GRAVITATIONAL INTERACTIONS OF ELEMENTARY PARTICLES

2004 ◽  
Vol 13 (10) ◽  
pp. 2355-2359 ◽  
Author(s):  
JONATHAN L. FENG ◽  
ARVIND RAJARAMAN ◽  
FUMIHIRO TAKAYAMA
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Particle Physics ◽  
Gravitational Constant ◽  
Planck Scale ◽  
Elementary Particles ◽  
Supersymmetric Particle ◽  
Small Scales ◽  
Physics Experiments ◽  
Shed Light

The gravitational interactions of elementary particles are suppressed by the Planck scale M*~1018 GeV and are typically expected to be far too weak to be probed by experiments. We show that, contrary to conventional wisdom, such interactions may be studied by particle physics experiments in the next few years. As an example, we consider conventional supergravity with a stable gravitino as the lightest supersymmetric particle. The next-lightest supersymmetric particle (NLSP) decays to the gravitino through gravitational interactions after about a year. This lifetime can be measured by stopping NLSPs at colliders and observing their decays. Such studies will yield a measurement of Newton's gravitational constant on unprecedentedly small scales, shed light on dark matter, and provide a window on the early universe.

Searches for new, massive particles with AMO experiments

2019 ◽  
pp. 29-81
Author(s):  
David DeMille
Keyword(s):  
Dark Matter ◽  
Cp Violation ◽  
Particle Physics ◽  
High Energy ◽  
Higgs Bosons ◽  
Substantial Impact ◽  
Molecular Hamiltonian ◽  
Physics Experiments ◽  
Pedagogical Goal ◽  
New Particles

These lectures aim to explain how certain types of atomic, molecular, and optical physics experiments can have a substantial impact in modern particle physics. A central pedagogical goal is to describe, using only concepts familiar to atomic experimentalists, how new particles can lead to new terms in the atomic or molecular Hamiltonian. Well-motivated examples are discussed, including potential dark matter candidates known as “dark photons”, known and as-yet unknown Higgs bosons, and supersymmetric particles leading to CP violation. The observable effects of new Hamiltonian terms associated with these phenomena are worked out, and state-of-the-art strategies for detecting them, using atomic and molecular experiments, are described for some cases. Remarkably, the sensitivity of atomic/molecular experiments can make it possible to detect new particles even more massive than those that can be created directly at the largest high-energy colliders.

DARK MATTER SEARCH

2002 ◽  
Vol 17 (24) ◽  
pp. 3421-3431 ◽  
Author(s):  
◽  
H. V. KLAPDOR-KLEINGROTHAUS
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Exciting Field ◽  
Dark Matter Search ◽  
The Status

Dark matter is at present one of the most exciting field of particle physics and cosmology. We review the status of undergound experiments looking for cold and hot dark matter.

scholarly journals Xenon-1T excess as a possible signal of a sub-GeV hidden sector dark matter

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Amin Aboubrahim ◽  
Michael Klasen ◽  
Pran Nath
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Small Mass ◽  
Big Bang ◽  
Mass Splitting ◽  
Recoil Energy ◽  
Dirac Fermions ◽  
Dark Sector ◽  
Dark Photon ◽  
Physics Model

Abstract We present a particle physics model to explain the observed enhancement in the Xenon-1T data at an electron recoil energy of 2.5 keV. The model is based on a U(1) extension of the Standard Model where the dark sector consists of two essentially mass degenerate Dirac fermions in the sub-GeV region with a small mass splitting interacting with a dark photon. The dark photon is unstable and decays before the big bang nucleosynthesis, which leads to the dark matter constituted of two essentially mass degenerate Dirac fermions. The Xenon-1T excess is computed via the inelastic exothermic scattering of the heavier dark fermion from a bound electron in xenon to the lighter dark fermion producing the observed excess events in the recoil electron energy. The model can be tested with further data from Xenon-1T and in future experiments such as SuperCDMS.

Least‐squares inversion of in‐situ sonic Q measurements: Stability and resolution

Geophysics ◽  
2004 ◽  
Vol 69 (2) ◽  
pp. 378-385 ◽  
Author(s):  
Aristotelis Dasios ◽  
Clive McCann ◽  
Timothy Astin
Keyword(s):  
High Resolution ◽  
Least Squares ◽  
Instantaneous Frequency ◽  
Spectral Ratio ◽  
Full Waveform ◽  
Multiple Measurements ◽  
Sandstone Reservoir ◽  
Gas Bearing

We minimize the effect of noise and increase both the reliability and the resolution of attenuation estimates obtained from multireceiver full‐waveform sonics. Multiple measurements of effective attenuation were generated from full‐waveform sonic data recorded by an eight‐receiver sonic tool in a gas‐bearing sandstone reservoir using two independent techniques: the logarithmic spectral ratio (LSR) and the instantaneous frequency (IF) method. After rejecting unstable estimates [receiver separation <2 ft (0.61 m)], least‐squares inversion was used to combine the multiple estimates into high‐resolution attenuation logs. The procedure was applied to raw attenuation data obtained with both the LSR and IF methods, and the resulting logs showed that the attenuation estimates obtained for the maximum receiver separation of 3.5 ft (1.07 m) provide a smoothed approximation of the high‐resolution measurements. The approximation is better for the IF method, with the normalized crosscorrelation factor between the low‐ and high‐resolution logs being 0.90 for the IF method and 0.88 for the LSR method.

A new parameter set for anisotropic multiparameter full-waveform inversion and application to a North Sea data set

Geophysics ◽  
2016 ◽  
Vol 81 (4) ◽  
pp. U25-U38 ◽  
Author(s):  
Nuno V. da Silva ◽  
Andrew Ratcliffe ◽  
Vetle Vinje ◽  
Graham Conroy
Keyword(s):  
North Sea ◽  
Waveform Inversion ◽  
Real Data ◽  
Model Parameters ◽  
Full Waveform Inversion ◽  
Radiation Patterns ◽  
Data Set ◽  
Full Waveform ◽  
Seismic Image ◽  
Central North Sea

Parameterization lies at the center of anisotropic full-waveform inversion (FWI) with multiparameter updates. This is because FWI aims to update the long and short wavelengths of the perturbations. Thus, it is important that the parameterization accommodates this. Recently, there has been an intensive effort to determine the optimal parameterization, centering the fundamental discussion mainly on the analysis of radiation patterns for each one of these parameterizations, and aiming to determine which is best suited for multiparameter inversion. We have developed a new parameterization in the scope of FWI, based on the concept of kinematically equivalent media, as originally proposed in other areas of seismic data analysis. Our analysis is also based on radiation patterns, as well as the relation between the perturbation of this set of parameters and perturbation in traveltime. The radiation pattern reveals that this parameterization combines some of the characteristics of parameterizations with one velocity and two Thomsen’s parameters and parameterizations using two velocities and one Thomsen’s parameter. The study of perturbation of traveltime with perturbation of model parameters shows that the new parameterization is less ambiguous when relating these quantities in comparison with other more commonly used parameterizations. We have concluded that our new parameterization is well-suited for inverting diving waves, which are of paramount importance to carry out practical FWI successfully. We have demonstrated that the new parameterization produces good inversion results with synthetic and real data examples. In the latter case of the real data example from the Central North Sea, the inverted models show good agreement with the geologic structures, leading to an improvement of the seismic image and flatness of the common image gathers.

scholarly journals Dark matter, dark energy and gravity

2015 ◽  
Vol 24 (02) ◽  
pp. 1550012 ◽  
Author(s):  
B. A. Robson
Keyword(s):  
Dark Matter ◽  
Dark Energy ◽  
Particle Physics ◽  
Composite Structures ◽  
Gravitational Interaction ◽  
Asymptotic Freedom ◽  
Generation Model ◽  
Newtonian Gravitation ◽  
Color Confinement ◽  
Vector Bosons

Within the framework of the Generation Model (GM) of particle physics, gravity is identified with the very weak, universal and attractive residual color interactions acting between the colorless particles of ordinary matter (electrons, neutrons and protons), which are composite structures. This gravitational interaction is mediated by massless vector bosons (hypergluons), which self-interact so that the interaction has two additional features not present in Newtonian gravitation: (i) asymptotic freedom and (ii) color confinement. These two additional properties of the gravitational interaction negate the need for the notions of both dark matter and dark energy.

scholarly journals Evaluation of a Multicommuted Flow System for Photometric Environmental Measurements

2006 ◽  
Vol 2006 ◽  
pp. 1-9 ◽  
Author(s):  
Eva Ródenas-Torralba ◽  
Fábio R. P. Rocha ◽  
Boaventura F. Reis ◽  
Ángel Morales-Rubio ◽  
Miguel de la Guardia
Keyword(s):  
Sodium Nitroprusside ◽  
Confidence Level ◽  
System Performance ◽  
Flow System ◽  
Flow Analysis ◽  
Light Emitting ◽  
Analysis Instrument ◽  
Hardware Configuration ◽  
Photometric Measurements

A portable flow analysis instrument is described for in situ photometric measurements. This system is based on light-emitting diodes (LEDs) and a photodiode detector, coupled to a multipumping flow system. The whole equipment presents dimensions of25 cm×22 cm×10 cm, weighs circa 3 kg, and costs 650 €. System performance was evaluated for different chemistries without changing hardware configuration for determinations of (i)Fe3+withSCN-, (ii) iodometric nitrite determination, (iii) phenol with sodium nitroprusside, and (iv) 1-naphthol-N-methylcarbamate (carbaryl) withp-aminophenol. The detection limits were estimated as 22, 60, 25, and 60 ngmL-1for iron, nitrite, phenol, and carbaryl at the 99.7% confidence level with RSD of 2.3, 1.0, 1.8, and 0.8%, respectively. Reagent and waste volumes were lower than those obtained by flow systems with continuous reagent addition. Sampling rates of 100, 110, 65, and 72 determinations per hour were achieved for iron, nitrite, phenol, and carbaryl determinations

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