347 research outputs found
Description of a domain by a squeezed state in a scalar field theory
The author attempted to describe a domain by using a squeezed state in
quantum field theory. An extended squeeze operator was used to construct the
state. In a scalar field theory, the author described a domain that the
distributions of the condensate and of the fluctuation are Gaussian. The
momentum distribution, chaoticity and correlation length were calculated. It
was found that the typical value of the momentum is about the inverse of the
domain size, and that the chaoticity reflects the ratio of the size of the
squeeze region to that of the coherent region. The results indicate that the
quantum state of a domain is surmised by these quantities under the assumption
that the distributions are Gaussian. As an example, this method was applied to
a pion field, and the momentum distribution and the chaoticity were shown.Comment: 10 pages, 5 figures, a typographical error in the reference is
correcte
Vertex operator approach for form factors of Belavin's -symmetric model
Belavin's -symmetric model is considered on the
basis of bosonization of vertex operators in the model and
vertex-face transformation. Free field representations of nonlocal tail
operators are constructed for off diagonal matrix elements with respect to the
ground state sectors. As a result, integral formulae for form factors of any
local operators in the -symmetric model can be
obtained, in principle.Comment: 24 pages, 4 figures, published in J. Phys. A: Math. Theor. 43 (2010)
085202. For the next thirty days from Feb 5 2010, the full text of the
article will be completely free to access through our 'This Month's Papers'
service (www.iop.org/journals/thismonth), helping you to benefit from maximum
visibilit
Parametric amplification with a friction in heavy ion collisions
We study the effects of the expansion of the system and the friction on the
parametric amplification of mesonic fields in high energy heavy ion collisions
within the linear model . The equation of motion which is similar to
Mathieu equation is derived to describe the time development of classical
fields in the last stage of a heavy ion collision after the freezeout time. The
enhanced mode is extracted analytically by comparison with Mathieu equation and
the equation of motion is solved numerically to examine whether soft modes will
be enhanced or not. It is found that the strong peak appears around 267 MeV in
the pion transverse momentum distribution in cases with weak friction and high
maximum temperature. This enhancement can be extracted by taking the ratio
between different modes in the pion transverse momentum distribution.Comment: 10 pages, 9 figures LaTeX: appendix adde
Compound basis arising from the basic -module
A new basis for the polynomial ring of infinitely many variables is
constructed which consists of products of Schur functions and Q-functions. The
transition matrix from the natural Schur function basis is investigated.Comment: 12 page
Form factors of the XXZ model and the affine quantum group symmetry
We present new expressions of form factors of the XXZ model which satisfy
Smirnov's three axioms. These new form factors are obtained by acting the
affine quantum group to the known ones obtained
in our previous works. We also find the relations among all the new and known
form factors, i.e., all other form factors can be expressed as kind of
descendents of a special one.Comment: 11 pages, latex; Some explanation is adde
Annihilation poles of a Smirnov-type integral formula for solutions to quantum Knizhnik--Zamolodchikov equation
We consider the recently obtained integral representation of quantum
Knizhnik-Zamolodchikov equation of level 0. We obtain the condition for the
integral kernel such that these solutions satisfy three axioms for form factor
\'{a} la Smirnov. We discuss the relation between this integral representation
and the form factor of XXZ spin chain.Comment: 14 pages, latex, no figures
Squeezed Correlations and Spectra for Mass-Shifted Bosons
Huge back-to-back correlations are shown to arise for thermal ensembles of
bosonic states with medium-modified masses. The effect is experimentally
observable in high energy heavy ion collisions.Comment: 4 pages (RevTex) including 2 eps figures via psfig, published versio
Elucidation of the molecular signatures of renal cell carcinoma by gene expression profiling
Renal cell carcinoma (RCC) is the 10th most common cancer in United States. It is a heterogeneous disease with various histologic types. Since high-throughput technologies such as microarrays have been introduced, molecular confirmation of previously known findings in RCC has been made and new molecular findings have emerged. We review the accumulating advances in this field and their clinical implications. The published data so far have proved to be significant and promising, and numerous microarray studies with larger number of cases are currently ongoing or being planned. Although various clinical parameters are being refined for diagnosis and prognosis, these data obtained by microarray studies will undoubtedly contribute to both and eventually impacts the treatment of RCC
Dynamical Pion Production via Parametric Resonance from Disoriented Chiral Condensate
We discuss a dynamical mechanism of pion production from disoriented chiral
condensates (DCC). It leads to an explosive production of pions via the
parametric amplification mechanism, which is similar to the reheating mechanism
in inflationary cosmology. Classically, it is related with the instability in
the solutions of the Mathieu equation and we explore the quantum aspects of the
mechanism. We show that nonlinearlities and back reactions can be ignorable for
sufficiently long time under the small amplitude approximations of background
oscillations, which may be appropriate for the late stage of
nonequilibrium phase transition. It allows us to obtain an explicit quantum
state of the produced pions and , the squeezed state of BCS type.
Single particle distributions and two-pion correlation functions are computed
within these approximations. The results obtained illuminate the characteristic
features of multi-pion states produced through the parametric amplification
mechanism. In particular, two-pion correlations of various charge combinations
contain back-to-back correlations which cannot be masked by the identical
particle interference effect.Comment: REVTEX 18 pages and 10 figure
Comprehensive Analysis of Market Conditions in the Foreign Exchange Market: Fluctuation Scaling and Variance-Covariance Matrix
We investigate quotation and transaction activities in the foreign exchange
market for every week during the period of June 2007 to December 2010. A
scaling relationship between the mean values of number of quotations (or number
of transactions) for various currency pairs and the corresponding standard
deviations holds for a majority of the weeks. However, the scaling breaks in
some time intervals, which is related to the emergence of market shocks. There
is a monotonous relationship between values of scaling indices and global
averages of currency pair cross-correlations when both quantities are observed
for various window lengths .Comment: 13 pages, 10 figure
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