48,063 research outputs found
Unparticle effects in rare (t -> c g g) decay
Rare (t -> c g g) decay can only appear at loop level in the Standard Model
(SM), and naturally they are strongly suppressed. These flavor changing decays
induced by the mediation of spin-0 and spin-2 unparticles, can appear at tree
level in unparticle physics. In this work the virtual effects of unparticle
physics in the flavor-changing (t -> c g g) decay is studied. Using the SM
result for the branching ratio of the (t -> c g g) decay, the parameter space
of d_U and Lambda_U, where the branching ratio of this decay exceeds the one
predicted by the SM, is obtained. Measurement of the branching ratio larger
than 10^(-9) can give valuable information for establishing unparticle physics.Comment: 15 pages, 7 figures, LaTeX formatte
A 233 km Tunnel for Lepton and Hadron Colliders
A decade ago, a cost analysis was conducted to bore a 233 km circumference
Very Large Hadron Collider (VLHC) tunnel passing through Fermilab. Here we
outline implementations of , , and collider
rings in this tunnel using recent technological innovations. The 240 and 500
GeV colliders employ Crab Waist Crossings, ultra low emittance damped
bunches, short vertical IP focal lengths, superconducting RF, and low
coercivity, grain oriented silicon steel/concrete dipoles. Some details are
also provided for a high luminosity 240 GeV collider and 1.75 TeV
muon accelerator in a Fermilab site filler tunnel. The 40 TeV
collider uses the high intensity Fermilab source, exploits high cross
sections for production of high mass states, and uses 2 Tesla ultra
low carbon steel/YBCO superconducting magnets run with liquid neon. The 35 TeV
muon ring ramps the 2 Tesla superconducting magnets at 9 Hz every 0.4 seconds,
uses 250 GV of superconducting RF to accelerate muons from 1.75 to 17.5 TeV in
63 orbits with 71% survival, and mitigates neutrino radiation with phase
shifting, roller coaster motion in a FODO lattice.Comment: LaTex, 6 pages, 1 figure, Advanced Accelerator Concepts Workshop,
Austin, TX, 10-15 June 201
Interpolation function of the genocchi type polynomials
The main purpose of this paper is to construct not only generating functions
of the new approach Genocchi type numbers and polynomials but also
interpolation function of these numbers and polynomials which are related to a,
b, c arbitrary positive real parameters. We prove multiplication theorem of
these polynomials. Furthermore, we give some identities and applications
associated with these numbers, polynomials and their interpolation functions.Comment: 14 page
Femtosecond Population Inversion and Stimulated Emission of Dense Dirac Fermions in Graphene
We show that strongly photoexcited graphene monolayers with 35fs pulses
quasi-instantaneously build up a broadband, inverted Dirac fermion population.
Optical gain emerges and directly manifests itself via a negative optical
conductivity for the first 200fs, where stimulated emission completely
compensates absorption loss in the graphene layer. Our experiment-theory
comparison with two distinct electron and hole chemical potentials reproduce
absorption saturation and gain at 40fs, revealing, particularly, the evolution
of the transient state from a hot classical gas to a dense quantum fluid with
increasing the photoexcitation
Two-loop Renormalization Group Equations in General Gauge Field Theories
The complete set of two-loop renormalization group equations in general gauge
field theories is presented. This includes the \beta functions of parameters
with and without a mass dimension
BDGS: A Scalable Big Data Generator Suite in Big Data Benchmarking
Data generation is a key issue in big data benchmarking that aims to generate
application-specific data sets to meet the 4V requirements of big data.
Specifically, big data generators need to generate scalable data (Volume) of
different types (Variety) under controllable generation rates (Velocity) while
keeping the important characteristics of raw data (Veracity). This gives rise
to various new challenges about how we design generators efficiently and
successfully. To date, most existing techniques can only generate limited types
of data and support specific big data systems such as Hadoop. Hence we develop
a tool, called Big Data Generator Suite (BDGS), to efficiently generate
scalable big data while employing data models derived from real data to
preserve data veracity. The effectiveness of BDGS is demonstrated by developing
six data generators covering three representative data types (structured,
semi-structured and unstructured) and three data sources (text, graph, and
table data)
Crystal orientation and thickness dependence of superconductivity on tetragonal FeSe1-x thin films
Superconductivity was recently found in the simple tetragonal FeSe structure.
Recent studies suggest that FeSe is unconventional, with the symmetry of the
superconducting pairing state still under debate. To tackle these problems,
clean single crystals and thin films are required. Here we report the
fabrication of superconducting beta-phase FeSe1-x thin films on different
substrates using a pulsed laser deposition (PLD) technique. Quite
interestingly, the crystal orientation, and thus, superconductivity in these
thin films is sensitive to the growth temperature. At 320C, films grow
preferably along c-axis, but the onset of superconductivity depends on film
thickness. At 500C, films grow along (101), with little thickness dependence.
These results suggest that the low temperature structural deformation
previously found is crucial to the superconductivity of this material
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