907 research outputs found
The QCD phase diagram in the space of imaginary chemical potential via 't Hooft anomalies
The QCD phase diagram in the space of temperature and imaginary baryon
chemical potential has been an interesting subject in numerical lattice QCD
simulations because of the absence of the sign problem and its deep structure
related to confinement/deconfinement. We study constraints on the phase diagram
by using an 't Hooft anomaly. The relevant anomaly is an anomaly in the space
of imaginary chemical potential. We compute it in the UV, and discuss how it is
matched by the pion effective field theory at low temperatures. Then we study
implications of the anomaly to the phase diagram. There must be a line of phase
transition studied in the past by Roberge and Weiss such that the expectation
value of the Polyakov loop is not smooth when we cross the line. Moreover, if
the greatest common divisor of the color and flavor numbers is greater than
one, the phase transition across the Roberge-Weiss line must be either a first
order phase transition, or a second order phase transition described by a
nontrivial interacting three-dimensional CFT.Comment: 28 pages, 6 figure
Runaway Dynamics and Supersymmetry Breaking
Supersymmetric SU(N_C) gauge theories possess runaway-type superpotentials
for N_F < N_C, where N_F is the flavor number of massless quarks. We show that
the runaway behavior can be stabilized for N_F nearly equal to N_C by
introducing singlets with the aid of perturbative corrections to the Kahler
potential, generating (local) minima of supersymmetry breaking.Comment: 6 page
Variant Supercurrents and Linearized Supergravity
In this paper the variant supercurrents based on consistency and completion
in off-shell N=1 supergravity are studied. We formulate the embedding relations
for supersymmetric current and energy tensor into supercurrent multiplet.
Corresponding linearized supergravity is obtained with appropriate choice of
Wess-Zumino gauge in each gravity supermultiplet.Comment: v1: 9 pp; v2: minor changes; v3: 10 pp, published versio
Near infrared imaging of the cometary globule CG12
Cometary globule 12 is a relatively little investigated medium- and low mass
star forming region 210 pc above the Galactic plane. NIR J, H, and Ks imaging
and stellar photometry is used to analyse the stellar content and the structure
of CG 12. Several new members and member candidates of the CG 12 stellar
cluster were found. The new members include in particular a highly embedded
source with a circumstellar disk or shell and a variable star with a
circumstellar disk which forms a binary with a previously known A spectral type
cluster member. The central source of the known collimated molecular outflow in
CG 12 and an associated "hourglass"-shaped object due to reflected light from
the source were also detected. HIRES-enhanced IRAS images are used together
with SOFI J,H,Ks imaging to study the two associated IRAS point sources,
13546-3941 and 13547-3944. Two new 12 micrometer sources coinciding with NIR
excess stars were detected in the direction of IRAS 13546-3941. The IRAS
13547-3944 emission at 12 and 25 micrometers originates in the Herbig AeBe star
h4636n and the 60 and 100 micrometer emission from an adjacent cold source.Comment: Accepted Astronomy and Astrophysics Oct. 15 200
A Preliminary Examination of Effect of Massage and Aroma Oil Massage in Foot Care Nursing
AbstractFoot care nursing is attracting attention as a medically effective treatment for the foot lesions caused by such problems as diabetes or aging. In this study, we experimentally examined how aromatherapy affects human brain functions during foot care nursing using near-infrared spectroscopy (NIRS). 11 subjects received both foot care nursing massages and aroma oil massages. We analyzed the changes in their oxygenated hemoglobin (oxy-Hb) concentrations based on their brain activity by t-tests, and the t-test results showed significant differences between two kinds of massages in both the somatosensory and prefrontal association areas. The oxy-Hb concentration in both massages with and without aroma oil also showed a tendency to decrease with time. Our questionnaire results showed that our subjects felt more comfortable and relaxed while receiving foot care nursing with aroma oils. These results suggest that aroma oil massages are an effective foot care nursing tool and that foot care nursing is a medically effective treatment
On the Trace Anomaly and the Anomaly Puzzle in N=1 Pure Yang-Mills
The trace anomaly of the energy-momentum tensor is usually quoted in the form
which is proportional to the beta function of the theory. However, there are in
general many definitions of gauge couplings depending on renormalization
schemes, and hence many beta functions. In particular, N=1 supersymmetric pure
Yang-Mills has the holomorphic gauge coupling whose beta function is one-loop
exact, and the canonical gauge coupling whose beta function is given by the
Novikov-Shifman-Vainshtein-Zakharov beta function. In this paper, we study
which beta function should appear in the trace anomaly in N=1 pure Yang-Mills.
We calculate the trace anomaly by employing the N=4 regularization of N=1 pure
Yang-Mills. It is shown that the trace anomaly is given by one-loop exact form
if the composite operator appearing in the trace anomaly is renormalized in a
preferred way. This result gives the simplest resolution to the anomaly puzzle
in N=1 pure Yang-Mills. The most important point is to examine in which scheme
the quantum action principle is valid, which is crucial in the derivation of
the trace anomaly.Comment: 25 pages, 1 figure; v2:slight correction in sec.5, minor addition in
appendi
Clarifying Some Remaining Questions in the Anomaly Puzzle
We discuss several points that may help to clarify some questions that remain
about the anomaly puzzle in supersymmetric theories. In particular, we consider
a general N=1 supersymmetric Yang-Mills theory. The anomaly puzzle concerns the
question of whether there is a consistent way to put the R-current and the
stress tensor in a single supercurrent, even though in the classical theory
they are in the same supermultiplet. As is well known, the classically
conserved supercurrent bifurcates into two supercurrents having different
anomalies in the quantum regime. The most interesting result we obtain is an
explicit expression for the lowest component of one of the two supercurrents in
4-dimensional spacetime, namely the supercurrent that has the energy-momentum
tensor as one of its components. This expression for the lowest component is an
energy-dependent linear combination of two chiral currents, which itself does
not correspond to a classically conserved chiral current. The lowest component
of the other supercurrent, namely, the R-current, satisfies the Adler-Bardeen
theorem. The lowest component of the first supercurrent has an anomaly that we
show is consistent with the anomaly of the trace of the energy-momentum tensor.
Therefore, we conclude that there is no consistent way to put the R-current and
the stress tensor in a single supercurrent in the quantized theory. We also
discuss and try to clarify some technical points in the derivations of the
two-supercurrents in the literature. These latter points concern the
significance of infrared contributions to the NSVZ beta-function and the role
of the equations of motion in deriving the two supercurrents.Comment: 22 pages, no figure. v2: minor changes. v3: sections re-organized.
new subsections (IVA, IVB) added. references adde
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