374 research outputs found
Dirac-mode expansion for confinement and chiral symmetry breaking
We develop a manifestly gauge-covariant expansion and projection using the
eigen-mode of the QCD Dirac operator. Applying this method to the Wilson loop
and the Polyakov loop, we perform a direct analysis of the correlation between
confinement and chiral symmetry breaking in SU(3) lattice QCD calculation on
6^4 at beta=5.6 at the quenched level. Notably, the Wilson loop is found to
obey the area law, and the slope parameter corresponding to the string tension
or the confinement force is almost unchanged, even after removing the low-lying
Dirac modes, which are responsible to chiral symmetry breaking. We find also
that the Polyakov loop remains to be almost zero even without the low-lying
Dirac modes, which indicates the Z_3-unbroken confinement phase. These results
indicate that one-to-one correspondence does not hold between confinement and
chiral symmetry breaking in QCD.Comment: 7 pages, 6 figures, Talk given at Conference: Lattice 201
Instantaneous Interquark Potential in Generalized Landau Gauge in SU(3) Lattice QCD: A Linkage between the Landau and the Coulomb Gauges
We investigate in detail "instantaneous interquark potentials", interesting
gauge-dependent quantities defined from the spatial correlators of the temporal
link-variable , in generalized Landau gauge using SU(3) quenched lattice
QCD. The instantaneous Q potential has no linear part in the
Landau gauge, and it is expressed by the Coulomb plus linear potential in the
Coulomb gauge, where the slope is 2-3 times larger than the physical string
tension. Using the generalized Landau gauge, we find that the instantaneous
potential can be continuously described between the Landau and the Coulomb
gauges, and its linear part rapidly grows in the neighborhood of the Coulomb
gauge. We also investigate the instantaneous 3Q potential in the generalized
Landau gauge, and obtain similar results to the Q case. -length
terminated Polyakov-line correlators and their corresponding "finite-time
potentials" are also investigated in generalized Landau gauge
The crepant transformation conjecture for toric complete intersections
Let X and Y be K-equivalent toric Deligne-Mumford stacks related by a single toric wall-crossing. We prove the Crepant Transformation Conjecture in this case, fully-equivariantly and in genus zero. That is, we show that the equivariant quantum connections for X and Y become gauge-equivalent after analytic continuation in quantum parameters. Furthermore we identify the gauge transformation involved, which can be thought of as a linear symplectomorphism between the Givental spaces for X and Y, with a Fourier-Mukai transformation between the K-groups of X and Y, via an equivariant version of the Gamma-integral structure on quantum cohomology. We prove similar results for toric complete intersections. We impose only very weak geometric hypotheses on X and Y: they can be non-compact, for example, and need not be weak Fano or have Gorenstein coarse moduli space. Our main tools are the Mirror Theorems for toric Deligne-Mumford stacks and toric complete intersections, and the Mellin-Barnes method for analytic continuation of hypergeometric functions
Off-diagonal Gluon Mass Generation and Infrared Abelian Dominance in Maximally Abelian Gauge in SU(3) Lattice QCD
In SU(3) lattice QCD formalism, we propose a method to extract gauge fields
from link-variables analytically. With this method, we perform the first study
on effective mass generation of off-diagonal gluons and infrared Abelian
dominance in the maximally Abelian (MA) gauge in the SU(3) case. Using SU(3)
lattice QCD, we investigate the propagator and the effective mass of the gluon
fields in the MA gauge with U(1)_3 \timesU(1)_8 Landau gauge fixing. The
Monte Carlo simulation is performed on at =5.7, 5.8 and 6.0 at
the quenched level. The off-diagonal gluons behave as massive vector bosons
with the approximate effective mass in the region of fm, and the propagation is
limited within a short range, while the propagation of diagonal gluons remains
even in a large range. In this way, infrared Abelian dominance is shown in
terms of short-range propagation of off-diagonal gluons. Furthermore, we
investigate the functional form of the off-diagonal gluon propagator. The
functional form is well described by the four-dimensional Euclidean Yukawa-type
function with
for fm. This also indicates that the spectral function of
off-diagonal gluons has the negative-value region
Mirage in Temporal Correlation functions for Baryon-Baryon Interactions in Lattice QCD
Single state saturation of the temporal correlation function is a key
condition to extract physical observables such as energies and matrix elements
of hadrons from lattice QCD simulations. A method commonly employed to check
the saturation is to seek for a plateau of the observables for large Euclidean
time. Identifying the plateau in the cases having nearby states, however, is
non-trivial and one may even be misled by a fake plateau. Such a situation
takes place typically for the system with two or more baryons. In this study,
we demonstrate explicitly the danger from a possible fake plateau in the
temporal correlation functions mainly for two baryons ( and ), and
three and four baryons ( and as well, employing
(2+1)-flavor lattice QCD at GeV on four lattice volumes with
2.9, 3.6, 4.3 and 5.8 fm. Caution is given for drawing conclusion on the
bound , and systems only based on the temporal correlation
functions.Comment: 32 pages, 13 figures, minor corrections, published version, typos
correcte
Hodge-theoretic mirror symmetry for toric stacks
Using the mirror theorem [CCIT15], we give a Landau-Ginzburg mirror description for the big equivariant quantum cohomology of toric Deligne-Mumford stacks. More precisely, we prove that the big equivariant quantum D-module of a toric Deligne-Mumford stack is isomorphic to the Saito structure associated to the mirror Landau-Ginzburg potential. We give a GKZ-style presentation of the quantum D-module, and a combinatorial description of quantum cohomology as a quantum Stanley-Reisner ring. We establish the convergence of the mirror isomorphism and of quantum cohomology in the big and equivariant setting
Precise Determination of Blackbody Radiation Shifts in a Strontium Molecular Lattice Clock
Molecular lattice clocks enable the search for new physics, such as fifth
forces or temporal variations of fundamental constants, in a manner
complementary to atomic clocks. Blackbody radiation (BBR) is a major
contributor to the systematic error budget of conventional atomic clocks and is
notoriously difficult to characterize and control. Here, we combine infrared
Stark-shift spectroscopy in a molecular lattice clock and modern quantum
chemistry methods to characterize the polarizabilities of the Sr molecule
from dc to infrared. Using this description, we determine the static and
dynamic blackbody radiation shifts for all possible vibrational clock
transitions to the level. This constitutes an important step towards
mHz-level molecular spectroscopy in Sr, and provides a framework for
evaluating BBR shifts in other homonuclear molecules.Comment: 6 pages, 4 figures, updated reference
LEUKEMIA-ASSOCIATED TRANSPLANTATION ANTIGENS RELATED TO MURINE LEUKEMIA VIRUS : THE X.1 SYSTEM: IMMUNE RESPONSE CONTROLLED BY A LOCUS LINKED TOH-2
Two BALB radiation leukemias are strongly rejected by hybrids of BALB with certain other mouse strains, although BALB mice themselves exhibit no detectable resistance whatever. Hybrids immunized with progressively increased inocula are resistant to 200 x 106 or more leukemia cells; their serum is cytotoxic for the leukemia cells in vitro and protects BALB mice against challenge with these BALB leukemias. The antigenic system thus identified has been named X.1. In (BALB x B6) hybrids the major determinant of resistance was shown to be a B6 gene in the K region of H-2. This is likely to be the Rgv-1 (Resistance to gross virus) locus of Lilly, which may thus be identified in this case as an Ir (Immune response) allele conferring ability to respond to X.1 antigen on MuLV and leukemia cells, and so responsible for production of X.1 antibody and the rejection of X.1+ leukemia cells by hybrid mice. Immunoelectron microscopy with X.1 antiserum (from immunized hybrids) shows labeling both on the cell surface and on virions produced by the leukemia cells. It is not known whether X.1 comprises only one or more than one antigen. Three radiation-induced BALB leukemias, one A strain radiation-induced leukemia, and 15/15 AKR primary spontaneous leukemias were typed X.1+ by the cytotoxicity test. Several other leukemias, including one induced by passage A Gross virus and one long-transplanted AKR ascites leukemia carried in (B6 x AKR)F1 hybrids, were X.1-. Normal mice of strains with a high incidence of leukemia and one other strain (129) express X.1 antigen, but evidently in amounts too small for certain detection in vitro; by the method of absorption in vivo, however, these strains could be typed X.1+ and other strains X.1-. We ascribe the X.1 antigen system tentatively to a sub-type of MuLV that is not passage A Gross virus and is probably not the dominant sub-type in strains with a high incidence of leukemia. After repeated passage in hybrids, one of the BALB leukemias became relatively resistant to rejection by the hybrid, partially lost its sensitivity to X.1 antiserum in vitro, and in electron micrographs was seen to produce fewer virions. The serum of untreated (BALB x B6) hybrids often contains cytotoxic antibody against leukemia cells, some of it probably anti-X.1. But another commonly occurring antibody, which is cytotoxic for C57BL leukemia EL4, appears to belong to another (undefined) system
Mirror Map as Generating Function of Intersection Numbers: Toric Manifolds with Two K\"ahler Forms
In this paper, we extend our geometrical derivation of expansion coefficients
of mirror maps by localization computation to the case of toric manifolds with
two K\"ahler forms. Especially, we take Hirzebruch surfaces F_{0}, F_{3} and
Calabi-Yau hypersurface in weighted projective space P(1,1,2,2,2) as examples.
We expect that our results can be easily generalized to arbitrary toric
manifold.Comment: 45 pages, 2 figures, minor errors are corrected, English is refined.
Section 1 and Section 2 are enlarged. Especially in Section 2, confusion
between the notion of resolution and the notion of compactification is
resolved. Computation under non-zero equivariant parameters are added in
Section
A terahertz vibrational molecular clock with systematic uncertainty at the level
Neutral quantum absorbers in optical lattices have emerged as a leading
platform for achieving clocks with exquisite spectroscopic resolution. However,
the studies of these clocks and their systematic shifts have so far been
limited to atoms. Here, we extend this architecture to an ensemble of diatomic
molecules and experimentally realize an accurate lattice clock based on pure
molecular vibration. We evaluate the leading systematics, including the
characterization of nonlinear trap-induced light shifts, achieving a total
systematic uncertainty of . The absolute frequency of the
vibrational splitting is measured to be 31 825 183 207 592.8(5.1) Hz, enabling
the dissociation energy of our molecule to be determined with record accuracy.
Our results represent an important milestone in molecular spectroscopy and
THz-frequency standards, and may be generalized to other neutral molecular
species with applications for fundamental physics, including tests of molecular
quantum electrodynamics and the search for new interactions.Comment: 17 pages, 8 figure
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