2,979 research outputs found
QCD Factorization for Spin-Dependent Cross Sections in DIS and Drell-Yan Processes at Low Transverse Momentum
Based on a recent work on the quantum chromodynamic (QCD) factorization for
semi-inclusive deep-inelastic scattering (DIS), we present a set of
factorization formulas for the spin-dependent DIS and Drell-Yan cross sections
at low transverse momentum.Comment: 12 pages, two figures include
Longitudinal/Goldstone boson equivalence and phenomenology of probing the electroweak symmetry breaking
We formulate the equivalence between the longitudinal weak-boson and the
Goldstone boson as a criterion for sensitively probing the electroweak symmetry
breaking mechanism and develop a precise power counting rule for chiral
Lagrangian formulated electroweak theories. With these we semi-quatitatively
analyze the sensitivities to various effective operators related to
electrowaeak symmetry breaking via weak-boson scatterings at the CERN Large
Hadron Collider (LHC).Comment: 6 pages, LaTex, 1 postscript figure included using psfig.te
Sensitivity of the LHC to Electroweak Symmetry Breaking: Equivalence Theorem as a Criterion
Based upon our recent study on the intrinsic connection between the
longitudinal weak-boson scatterings and probing the electroweak symmetry
breaking (EWSB) mechanism, we reveal the profound physical content of the
Equivalence Theorem (ET) as being able to discriminate physical processes which
are sensitive/insensitive to probing the EWSB sector. With this physical
content of the ET as a criterion, we analyze the complete set of the bosonic
operators in the electroweak chiral Lagrangian and systematically classify the
sensitivities to probing all these operators at the CERN LHC via the weak-boson
fusion in channel. This is achieved by developing a precise power
counting rule (a generalization from Weinberg's counting method) to {\it
separately} count the power dependences on the energy and all relevant mass
scales.Comment: 33 pages, LaTeX, 10 figures and Table-1b are in the separate file
figtab.uu. (The only change made from the previous version is to fix the bugs
in the uuencoded file.
Threshold Resummation for Higgs Production in Effective Field Theory
We present an effective field theory to resum the large double logarithms
originated from soft-gluon radiations at small final-state hadron invariant
masses in Higgs and vector boson (\gamma^*, and ) production at hadron
colliders. The approach is conceptually simple, indepaendent of details of an
effective field theory formulation, and valid to all orders in sub-leading
logarithms. As an example, we show the result of summing the
next-to-next-to-next leading logarithms is identical to that of standard pQCD
factorization method.Comment: A version to appear in Phys. Rev.
VLBI astrometry of two millisecond pulsars
We present astrometric results on two millisecond pulsars, PSR B1257+12 and
PSR J1022+1001, as carried out through VLBI. For PSR B1257+12, a
model-independent distance of pc and proper motion of
( mas/yr,
mas/yr) were obtained from 5 epochs of VLBA and 4 epochs of EVN observations,
spanning about 2 years. The two dimensional proper motion of PSR J1022+1001
( mas/yr, mas/yr) was
also estimated, using 3 epochs of EVN observations. Based on our results, the
X-ray efficiency of PSR B1257+12 should be in the same range as other
millisecond pulsars, and not as low as previously thought.Comment: Proceedings of IAUS 291 "Neutron Stars and Pulsars: Challenges and
Opportunities after 80 years", J. van Leeuwen (ed.); 3 page
Building quantum neural networks based on swap test
Artificial neural network, consisting of many neurons in different layers, is
an important method to simulate humain brain. Usually, one neuron has two
operations: one is linear, the other is nonlinear. The linear operation is
inner product and the nonlinear operation is represented by an activation
function. In this work, we introduce a kind of quantum neuron whose inputs and
outputs are quantum states. The inner product and activation operator of the
quantum neurons can be realized by quantum circuits. Based on the quantum
neuron, we propose a model of quantum neural network in which the weights
between neurons are all quantum states. We also construct a quantum circuit to
realize this quantum neural network model. A learning algorithm is proposed
meanwhile. We show the validity of learning algorithm theoretically and
demonstrate the potential of the quantum neural network numerically.Comment: 10 pages, 13 figure
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