200 research outputs found
Conformal Window of Gauge Theories with Four-Fermion Interactions and Ideal Walking
We investigate the effects of four-fermion interactions on the phase diagram
of strongly interacting theories for any representation as function of the
number of colors and flavors. We show that the conformal window, for any
representation, shrinks with respect to the case in which the four-fermion
interactions are neglected. The anomalous dimension of the mass increases
beyond the unity value at the lower boundary of the new conformal window. We
plot the new phase diagram which can be used, together with the information
about the anomalous dimension, to propose ideal models of walking technicolor.
We discover that when the extended technicolor sector, responsible for giving
masses to the standard model fermions, is sufficiently strongly coupled the
technicolor theory, in isolation, must have an infrared fixed point for the
full model to be phenomenologically viable. Using the new phase diagram we show
that the simplest one family and minimal walking technicolor models are the
archetypes of models of dynamical electroweak symmetry breaking. Our
predictions can be verified via first principle lattice simulations.Comment: RevTeX4, 22 pages, 16 figure
Laccase-catalyzed decolorization of the synthetic azo-dye diamond black PV 200 and of some structurally related derivatives
The kinetics of laccase-catalyzed transformation of the azo-dye Diamond Black PV 200 (CI Mordant Black 9) and various related synthesized derivatives were analyzed for dependence on pH and substrate structure. The reaction mixture of Diamond Black PV 200 was analyzed
by HPLC/MS_/MS and it was shown that upon laccase oxidation, reactive chinoid fragments of lower molecular weight were formed. These may further oligomerize as indicated by the appearance of a number of compounds
with increased molecular weight. The pH optimum for the decolorization was pH 5 for Diamond Black PV 200 which did not change significantly when the substitution pattern of its basic structure was varied. Biodegradability, however, was strongly dependent on the structure of the dyes
Bounds on fourth generation induced Lepton Flavour Violating double insertions in Supersymmetry
We derive bounds on leptonic double mass insertions of the type
in four generational MSSM, using the present
limits on . Two main features distinguish the rates of
these processes in MSSM4 from MSSM3 : (a) tan is restricted to be very
small and (b) the large masses for the fourth generation leptons.
In spite of small , there is an enhancement in amplitudes with
() type insertions which pick up the
mass of the fourth generation lepton, . We find these bounds to be
at least two orders of magnitude more stringent than those in MSSM3.Comment: Latex, 15 pages and 7 figures, Published versio
Increased secretion of salivary glands produced by facial vibrotactile stimulation
Patients with low-back pain can be evaluated immediately by means of an electrical tool that produces bony vibration to the lumbar spinal processes (Yrjama M, Vanharanta H. Bony vibrotactile stimulation: A new, non-invasive method for examining intradiscal pain. European Spine Journal 1994;3:233–235). In the rehabilitation of masticatory disturbance and dysphagia, an electric toothbrush is commonly used as an oral motor exercise tool for the facilitation of blood flow and metabolism in the orofacial region in Japanese hospitals. However, subjects receiving vibration in the facial regions reported increased salivary secretion. We attempted to develop an oral motor exercise apparatus modified by a headphone headset that was fixed and could be used for extended periods. The vibration apparatus of the heating conductor is protected by the polyethyle methacrylate (dental mucosa protective material), and electric motors for vibration control of the PWM circuit. We examined the amount of salivation during vibration stimuli on the bilateral masseter muscle belly, using a cotton roll positioned at the opening of the secretory duct for 3 min. Although the quantity of salivation in each subject showed various and large fluctuations in the right and left sides of the parotid and submandibular and sublingual glands, one or more of the salivary glands were effectively stimulated by 89 Hz vibration. The reported apparatus will be useful as an additional method in orofacial rehabilitation
Analysis of techni-dilaton as a dark matter candidate
The almost conformal dynamics of walking technicolor (TC) implies the
existence of the approximate scale invariance, which breaks down spontaneously
by the condensation of anti-techni and techni-fermions. According to the
Goldstone theorem, a spinless, parity-even particle, called techni-dilaton
(TD), then emerges at low energy. If TC exhibits an extreme walking, TD mass is
parametrically much smaller than that of techni-fermions (around 1 TeV), while
its decay constant is comparable to the cutoff scale of walking TC. We analyze
the light, decoupled TD as a dark matter candidate and study cosmological
productions of TD, both thermal and non-thermal, in the early Universe. The
thermal population is governed dominantly by single TD production processes
involving vertices breaking the scale symmetry, while the non-thermal
population is by the vacuum misalignment and is accumulated via harmonic and
coherent oscillations of misaligned classical TD fields. The non-thermal
population turns out to be dominant and large enough to explain the abundance
of presently observed dark matter, while the thermal population is highly
suppressed due to the large TD decay constant. Several cosmological and
astrophysical limits on the light, decoupled TD are examined to find that the
TD mass is constrained to be in a range between 0.01 eV and 500 eV. From the
combined constraints on cosmological productions and astrophysical
observations, we find that the light, decoupled TD can be a good dark matter
candidate with the mass around a few hundreds of eV for typical models of
(extreme) walking TC. We finally mention possible designated experiments to
detect the TD dark matter.Comment: 26 pages. 16 figures; v2, expanded Section 2.4 on composite Higgs in
light of newly discovered Higgs-like particle at LH
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