scholarly journals Coulomb drag of massless fermions in graphene

2011 ◽  
Vol 83 (16) ◽  
Author(s):  
Seyoung Kim ◽  
Insun Jo ◽  
Junghyo Nah ◽  
Z. Yao ◽  
S. K. Banerjee ◽  
...  
Keyword(s):  
Coulomb Drag ◽  
Massless Fermions

scholarly journals CONVOLUTION FORMULA AND FINITE W BOSON WIDTH EFFECTS IN TOP QUARK WIDTH

2008 ◽  
Vol 23 (22) ◽  
pp. 3525-3533 ◽  
Author(s):  
G. CALDERÓN ◽  
G. LÓPEZ CASTRO
Keyword(s):  
Top Quark ◽  
W Boson ◽  
Matrix Theory ◽  
Finite Width ◽  
Current Limit ◽  
Fermion Masses ◽  
Convolution Formula ◽  
Boson Resonance ◽  
Three Body ◽  
Massless Fermions

In the Standard Model, the top quark decay width Γt is computed from the exclusive t → bW decay. We argue in favor of using the three body decays [Formula: see text] to compute Γt as a sum over these exclusive modes. As dictated by the S-matrix theory, these three body decays of the top quark involve only asymptotic states and incorporate the width of the W boson resonance in a natural way. The convolution formula commonly used to include the finite width effects is found to be valid, in the general case, when the intermediate resonance couples to a conserved current (limit of massless fermions in the case of W bosons). The relation Γt = Γ(t → bW) is recovered by taking the limit of massless fermions followed by the W boson narrow width approximation. Although both calculations of Γt are different at the formal level, their results would differ only by tiny effects induced by light fermion masses and higher-order radiative corrections.

Experimental studies of Coulomb drag between ballistic quantum wires

2001 ◽  
Vol 13 (14) ◽  
pp. 3389-3402 ◽  
Author(s):  
P Debray ◽  
V Zverev ◽  
O Raichev ◽  
R Klesse ◽  
P Vasilopoulos ◽  
...  
Keyword(s):  
Quantum Wires ◽  
Experimental Studies ◽  
Coulomb Drag

FORESAIL-1 and ESTCube-2 Cubesat experiments of Coulomb drag propulsion

2021 ◽  
Author(s):  
Pekka Janhunen ◽  
Petri Toivanen ◽  
Jarmo Kivekäs ◽  
Matias Meskanen ◽  
Jouni Polkko
Keyword(s):  
Solar Wind ◽  
Orbital Motion ◽  
General Purpose ◽  
Low Earth Orbit ◽  
Voltage Source ◽  
Status Report ◽  
Plasma Stream ◽  
Low Thrust ◽  
Coulomb Drag ◽  
Positive Mode

<p>Coulomb drag propulsion taps momentum from a natural plasma stream to generate propellantless low-thrust propulsion for a spacecraft. The plasma is attached to by means of a long, thin, charged metallic tether. The tether's electrostatic field deflects the motion of streaming plasma ions and transfers momentum from them. The technique can be applied in the solar wind (i.e., outside Earth's magnetosphere) to produce general-purpose interplanetar propulsion. This application is called the electric solar wind sail (E-sail). It can also be applied in low Earth orbit (LEO) to brake the satellite's orbital motion. Here the relevant plasma stream is the ram flow of the ionosphere due to the satellite's orbital motion. This application is called the plasma brake and it is useful for satellite deorbiting for mitigating the growing problem of orbital debris.</p> <p>Here we report on progress of two CubeSat missions (FORESAIL-1 and ESTCube-2) that are under construction for measuring the Coulomb drag effect in LEO.  Both are scheduled to fly in 2022. Both satellites deploy up to 300 m long tether, charge it up by a high-voltage source and measure the resulting Coulomb drag. The satellites are slowly spinning and the tether is tightened by the centrifugal force. The tether is deployed from a reel which is rotated slowly by an electric motor.  Both satellites use negative tether polarity, which is the case relevant for the plasma brake. ESTCube-2 contains, in addition, a positive mode experiment which is relevant for the E-sail. The plasma environment in LEO differs from the solar wind, so the measured positive mode Coulomb drag must be scaled to yield a prediction of the strength of the E-sail effect in the solar wind.</p> <p>The Coulomb drag is measured by two independent methods. In the first method we set the tether voltage on and off in sync with the satellite's rotation and thereby accumulate a change of the system's angular momentum. The Coulomb drag is inferred from the measured change of the spin rate per time unit. In the second method we estimate Coulomb drag from the speeded-up lowering of the satelllite's orbital altitude.</p> <p>The presentation is a status report of the technical progress of these two Coulomb drag CubeSat missions; FORESAIL-1 and ESTCube-2.</p>

scholarly journals Chiral fluids: a few theoretical issues

2018 ◽  
Vol 182 ◽  
pp. 02131
Author(s):  
V. I. Zakharov ◽  
O. V. Teryaev
Keyword(s):  
Chiral Fluids ◽  
Theoretical Issues ◽  
Massless Fermions

We review briefly a few topic concerning physics of fluids whose constituents are massless fermions interacting in chiral invariant way. Macroscopic manifestations of the chral anomaly is one of central issues. Another topic is ultraviolet vs infrared sensistivity of chiral magnetic and vortical effects. To clarify dynamical issues involved we rely mostly on a (well-known) toy model of pionic superfluidity.

scholarly journals Coulomb Drag by Small Momentum Transfer between Quantum Wires

2003 ◽  
Vol 91 (12) ◽  
Author(s):  
M. Pustilnik ◽  
E. G. Mishchenko ◽  
L. I. Glazman ◽  
A. V. Andreev
Keyword(s):  
Momentum Transfer ◽  
Quantum Wires ◽  
Small Momentum Transfer ◽  
Coulomb Drag ◽  
Small Momentum

scholarly journals NUMERICAL SOLUTIONS IN 5D STANDING WAVE BRANEWORLD

2013 ◽  
Vol 28 (20) ◽  
pp. 1350092 ◽  
Author(s):  
MERAB GOGBERASHVILI ◽  
OTARI SAKHELASHVILI ◽  
GIORGI TUKHASHVILI
Keyword(s):  
Standing Wave ◽  
Numerical Solutions ◽  
Braneworld Model ◽  
The Right ◽  
Matter Fields ◽  
Massless Fermions ◽  
Kaluza Klein

Within the 5D standing wave braneworld model numerical solutions of the equations for matter fields with various spins are found. It is shown that corresponding action integrals are factorizable and convergent over the extra coordinate, i.e. 4D fields are localized on the brane. We find that only left massless fermions are localized on the brane, while the right fermions are localized in the bulk. We demonstrate also quantization of Kaluza–Klein excited modes in our model.

scholarly journals Mesoscopic Coulomb Drag, Broken Detailed Balance, and Fluctuation Relations

2010 ◽  
Vol 104 (7) ◽  
Author(s):  
Rafael Sánchez ◽  
Rosa López ◽  
David Sánchez ◽  
Markus Büttiker
Keyword(s):  
Detailed Balance ◽  
Coulomb Drag ◽  
Fluctuation Relations
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