111,716 research outputs found
Electroweak Cross-sections and Widths
The status of W and Z cross-section and width measurements from the CDF and
D0 experiments is reviewed. Recent results that are discussed: the
cross-section for Z production times the branching ratio to tau pairs, the
rapidity and transverse momentum distributions of Z production in the electron
channel, and the direct measurements of the W width and the Z invisible width;
the latter from an analysis of events with large missing transverse energy and
one or more energetic jets.Comment: Contribution to the Proceedings of the 34th International Conference
on High Energy Physics; 4 pages, 2 figure
A Holistic Investigation on Terahertz Propagation and Channel Modeling Toward Vertical Heterogeneous Networks
User-centric and low latency communications can be enabled not only by small
cells but also through ubiquitous connectivity. Recently, the vertical
heterogeneous network (V-HetNet) architecture is proposed to backhaul/fronthaul
a large number of small cells. Like an orchestra, the V-HetNet is a polyphony
of different communication ensembles, including geostationary orbit (GEO), and
low-earth orbit (LEO) satellites (e.g., CubeSats), and networked flying
platforms (NFPs) along with terrestrial communication links. In this study, we
propose the Terahertz (THz) communications to enable the elements of V-HetNets
to function in harmony. As THz links offer a large bandwidth, leading to
ultra-high data rates, it is suitable for backhauling and fronthauling small
cells. Furthermore, THz communications can support numerous applications from
inter-satellite links to in-vivo nanonetworks. However, to savor this harmony,
we need accurate channel models. In this paper, the insights obtained through
our measurement campaigns are highlighted, to reveal the true potential of THz
communications in V-HetNets.Comment: It has been accepted for the publication in IEEE Communications
Magazin
Precision Measurements of the W-Boson Mass
The Standard Model of electroweak interactions has had great success in
describing the observed data over the last three decades. The precision of
experimental measurements affords tests of the Standard Model at the quantum
loop level beyond leading order. Despite this great success it is important to
continue confronting experimental measurements with the Standard Model
predictions as any deviation would signal new physics. As a fundamental
parameter of the Standard Model, the mass of the W-boson, M_W, is of particular
importance. Aside from being an important test of the SM itself, a precision
measurement of M_W can be used to constrain the mass of the Higgs boson, M_H.
In this article we review the principal experimental techniques for determining
M_W and discuss their combination into a single precision M_W measurement,
which is then used to yield constraints on M_H. We conclude by briefly
discussing future prospects for precision measurements of the W-boson mass.Comment: 37 pages, 13 figures, LaTex, to be published in volume 50 of Annual
Review of Nuclear and Particle Scienc
Wideband Self-Adaptive RF Cancellation Circuit for Full-Duplex Radio: Operating Principle and Measurements
This paper presents a novel RF circuit architecture for self-interference
cancellation in inband full-duplex radio transceivers. The developed canceller
is able to provide wideband cancellation with waveform bandwidths in the order
of 100 MHz or beyond and contains also self-adaptive or self-healing features
enabling automatic tracking of time-varying self-interference channel
characteristics. In addition to architecture and operating principle
descriptions, we also provide actual RF measurements at 2.4 GHz ISM band
demonstrating the achievable cancellation levels with different bandwidths and
when operating in different antenna configurations and under low-cost highly
nonlinear power amplifier. In a very challenging example with a 100 MHz
waveform bandwidth, around 41 dB total cancellation is obtained while the
corresponding cancellation figure is close to 60 dB with the more conventional
20 MHz carrier bandwidth. Also, efficient tracking in time-varying reflection
scenarios is demonstrated.Comment: 7 pages, to be presented in 2015 IEEE 81st Vehicular Technology
Conferenc
Analytical and numerical modeling methods for impedance analysis of single cells on-chip
Electrical impedance spectroscopy (EIS) is a noninvasive method for characterizing the dielectric properties of biological particles. The technique can differentiate between cell types and provide information on cell properties through measurement of the permittivity and conductivity of the cell membrane and cytoplasm. In terms of lab-on-a-chip (LOC) technology, cells pass sequentially through the microfluidic channel at high speed and are analyzed individually, rather than as traditionally done on a mixture of particles in suspension. This paper describes the analytical and numerical modeling methods for EIS of single cell analysis in a microfluidic cytometer. The presented modeling methods include Maxwell’s mixture theory, equivalent circuit model and finite element method. The difference and advantages of these methods have been discussed. The modeling work has covered the static case — an immobilized cell in suspension and the dynamic case — a moving cell in the channel
Energy Calibration of b-Quark Jets with Z->b-bbar Decays at the Tevatron Collider
The energy measurement of jets produced by b-quarks at hadron colliders
suffers from biases due to the peculiarities of the hadronization and decay of
the originating B hadron. The impact of these effects can be estimated by
reconstructing the mass of Z boson decays into pairs of b-quark jets. From a
sample of 584 pb-1 of data collected by the CDF experiment in 1.96 TeV
proton-antiproton collisions at the Tevatron collider, we show how the Z signal
can be identified and measured. Using the reconstructed mass of Z candidates we
determine a jet energy scale factor for b-quark jets with a precision better
than 2%. This measurement allows a reduction of one of the dominant source of
uncertainty in analyses based on high transverse momentum b-quark jets. We also
determine, as a cross-check of our analysis, the Z boson cross section in
hadronic collisions using the b-bbar final state as sigma x B(Z->b-bbar) = 1578
+636 -410 pb.Comment: 35 pages, 9 figures, submitted to Nuclear Instruments and Methods in
Physics Research Section
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