803 research outputs found
Diphoton Excess as a Hidden Monopole
We provide a theory with a monopole of a strongly-interacting hidden U(1)
gauge symmetry that can explain the 750-GeV diphoton excess reported by ATLAS
and CMS. The excess results from the resonance of monopole, which is produced
via gluon fusion and decays into two photons. In the low energy, there are only
mesons and a monopole in our model because any baryons cannot be gauge
invariant in terms of strongly interacting Abelian symmetry. This is
advantageous of our model because there is no unwanted relics around the BBN
epoch.Comment: 6 pages, 1 figur
Semi-direct Gauge Mediation in Conformal Windows of Vector-like Gauge Theories
Direct gauge mediation models using the Intriligator-Seiberg-Shih (ISS)
metastable vacua suffer from the Landau pole problem of the standard model
gauge couplings and the existence of R symmetry forbidding gaugino masses.
These problems may be solved by using the recently proposed SUSY breaking
models in a conformal window of the vector-like gauge theory with
gauge singlets. In this paper we propose a model of gauge mediation based on
the SUSY-breaking model in the conformal window, and study the dynamics for the
SUSY breaking. In the model, there are massive vector-like bifundamental fields
charged under both and the standard model gauge group, and our model
can be regarded as a semi-direct gauge mediation model. The color number
can be small to avoid the Landau pole problem, and the R symmetry is also
broken under a reasonable assumption on the strong dynamics of the model. The
model possesses only one free parameter, and the gaugino and sfermion masses
are naturally of the same order.Comment: 21 pages, 1 figur
Relaxing a constraint on the number of messengers in a low-scale gauge mediation
We propose a mechanism for relaxing a constraint on the number of messengers
in low-scale gauge mediation models. The Landau pole problem for the
standard-model gauge coupling constants in the low-scale gauge mediation can be
circumvented by using our mechanism. An essential ingredient is a large
positive anomalous dimension of messenger fields given by a large Yukawa
coupling in a conformal field theory at high energies. The positive anomalous
dimension reduces the contribution of the messengers to the beta function of
the standard-model gauge couplings.Comment: 22pages; v2:explanations expanded in sec.3.2, reference adde
Venture Capital in Japan: A Financial Instrument Supporting the Innovativeness of the Japanese Economy
Two factors: First, the relatively small number of new companies as well as the number of companies subject to liquidation over the year ("firm turnover") in Japan, and second, the insignificant prestige associated with the profession of entrepreneur do not foster growth in the dynamics of this form of financing ventures. The cited indicator for Japan in among the lowest in comparison with other highly developed countries1, while the profession of entrepreneur is not the foremost dream of college graduates. They would much rather prefer realizing their professional careers as members of the government bureaucracy or employees of a major corporation2. However, this mindset is slowly changing, if for no other reason then, in spite of popular conviction, because most small companies are not established during periods of prosperity, but near the end of the downward phase of the economic cycle. That is exactly the phase Japan has been dealing with for several years now. Young, creative people, recruited from the unemployed, are seeking self-employment, using all possible opportunities embedded in the "again starting up" machinery of the economy.Dwa czynniki: pierwszy - stosunkowo mała liczba nowych firm, a także firm likwidowanych w skali roku ("firm turnover") w Japonii oraz drugi - niewielki prestiż, jakim cieszy się zawód przedsiębiorcy, nie sprzyjają dynamizacji omawianej formy finansowania przedsięwzięć. Cytowany wskaźnik, dla Japonii należy do najniższych w porównaniu z innymi krajami wysoko rozwiniętymi (Grabowiecki 2000), zaś profesja przedsiębiorcy nie jest szczytem marzeń ludzi po studiach. Znacznie bardziej chcieliby oni swoją karierę zawodową realizować jako członkowie rządowej biurokracji lub pracownicy dużej korporacji (Corver 2008, s. 2). Ta świadomość ulega jednak stopniowej zmianie, chociażby dlatego, że wbrew popularnym przekonaniom, większość niewielkich przedsiębiorstw, powstaje nie w okresie prosperity, lecz pod koniec spadkowej fazy cyklu koniunkturalnego. Z taką fazą mamy do czynienia w Japonii od paru lat. Młodzi, kreatywni ludzie, rekrutujący się z bezrobotnych, poszukują samozatrudnienia, wykorzystują wszelakie szanse, tkwiące w "ruszającej na powrót" maszynerii gospodark (Yonekura, Lynskey 2003, s. 11)
Gauge Mediation with Sequestered Supersymmetry Breaking
Gauge mediation models have two drawbacks, that is, the so-called \mu-problem
and a lack of predictability of the gravitino dark matter abundance. We show
that conformal sequestering in the supersymmetry breaking sector offers
attractive solutions to both problems. The correct mass scale of the \mu and
B_\mu terms is generated by taking the gravitino mass of O(100) GeV without
causing the flavor-changing neutral-current problem. Moreover, a large
anomalous dimension of the supersymmetry breaking field naturally realizes the
small stau and neutralino mass difference required for the coannihilation to
work yielding the right dark matter abundance.Comment: 23 pages, 4 figures, 2 table
Observations of [C II] 158 micron Line and Far-infrared Continuum Emission toward the High-latitude Molecular Clouds in Ursa Major
We report the results of a rocket-borne observation of [C II] 158\micron line
and far-infrared continuum emission at 152.5\micron toward the high latitude
molecular clouds in Ursa Major. We also present the results of a follow-up
observation of the millimeter ^{12}CO J=1-0 line over a selected region
observed by the rocket-borne experiment. We have discovered three small CO
cloudlets from the follow-up ^{12}CO observations. We show that these molecular
cloudlets, as well as the MBM clouds(MBM 27/28/29/30), are not gravitationally
bound. Magnetic pressure and turbulent pressure dominate the dynamic balance of
the clouds. After removing the HI-correlated and background contributions, we
find that the [C II] emission peak is displaced from the 152.5\micron and CO
peaks, while the 152.5\micron continuum emission is spatially correlated with
the CO emission. We interpret this behavior by attributing the origin of [C II]
emission to the photodissociation regions around the molecular clouds
illuminated by the local UV radiation field. We also find that the ratio of the
molecular hydrogen column density to velocity-integrated CO intensity is
1.19+-0.29x10^{20} cm^{-2} (K kms^{-1})^{-1} from the FIR continuum and the CO
data. The average [C II] /FIR intensity ratio over the MBM clouds is 0.0071,
which is close to the all sky average of 0.0082 reported by the FIRAS on the
COBE satellite. The average [C II]/CO ratio over the same regions is 420, which
is significantly lower than that of molecular clouds in the Galactic plane.Comment: 15 pages, LaTeX (aaspp4.sty) + 2 tables(apjpt4.sty) + 6 postscript
figures; accepted for publication in the Astrophysical Journal; Astrophys. J.
in press (Vol. 490, December 1, 1997 issue
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