24,112 research outputs found
Gauge-Higgs Unification at the LHC
Higgs boson production by the gluon fusion and its decay into two photons at
the LHC are investigated in the context of the gauge-Higgs unification
scenario. The qualitative behaviors for these processes in the scenario are
quite distinguishable from those of the Standard Model and the universal extra
dimension scenario because of the overall sign difference for the effective
couplings induced by one-loop corrections through Kaluza-Klein modes.Comment: 7 pages, 2 figures, To appear in the proceedings of 2009 Nagoya
Global COE Workshop, Strong Coupling Gauge Theories in LHC era (SCGT09),
December 8-11 2009, Nagoya, Japa
The Unificatory Power of Scientific Realism
The no-miracles argument (Putnam, 1975) holds that science is successful because successful theories are (approximately) true. Frost-Arnold (2010) objects that this argument is unacceptable because it generates neither new predictions nor unifications. It is similar to the unacceptable explanation that opium puts people to sleep because it has a dormative virtue. I reply that on close examination, realism explains not only why some theories are successful but also why successful theories exist in current science. Therefore, it unifies the disparate phenomena
String Consistency for Unified Model Building
We explore the use of real fermionization as a test case for understanding
how specific features of phenomenological interest in the low-energy effective
superpotential are realized in exact solutions to heterotic superstring theory.
We present pedagogic examples of models which realize SO(10) as a level two
current algebra on the world-sheet, and discuss in general how higher level
current algebras can be realized in the tensor product of simple constituent
conformal field theories. We describe formal developments necessary to compute
couplings in models built using real fermionization. This allows us to isolate
cases of spin structures where the standard prescription for real
fermionization may break down.Comment: harvmac (available from xxx.lanl.gov), 30 pages (reduced format), if
you are using harvmac for the first time, make sure to adjust the "site
dependent options" at the beginning of the harvmac file. Shortened
introduction and added table 3, listing the complete massless spectrum with
U(1) charges of Model A. Version to appear in journa
750 GeV Diphotons from a D3-brane
Motivated by the recently reported diphoton excess at 750 GeV observed by
both CMS and ATLAS, we study string-based particle physics models which can
accommodate this signal. Quite remarkably, although Grand Unified Theories in
F-theory tend to impose tight restrictions on candidate extra sectors, the case
of a probe D3-brane near an E-type Yukawa point naturally leads to a class of
strongly coupled models capable of accommodating the observed signature. In
these models, the visible sector is realized by intersecting 7-branes, and the
750 GeV resonance is a scalar modulus associated with motion of the D3-brane in
the direction transverse to the Standard Model 7-branes. Integrating out heavy
3-7 string messenger states leads to dimension five operators for gluon fusion
production and diphoton decays. Due to the unified structure of interactions,
these models also predict that there should be additional decay channels to ZZ
and Z gamma. We also comment on models with distorted unification, where both
the production mechanism and decay channels can differ.Comment: v3: 12 pages, 1 figure, clarifications adde
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