430 research outputs found
On the enumeration of finite -algebras
We use Constraint Satisfaction Methods to construct and enumerate finite
-algebras up to isomorphism. These objects were recently introduced by Rump
and appear in Garside theory, algebraic logic, and the study of the
combinatorial Yang-Baxter equation. There are 377322225 isomorphism classes of
-algebras of size eight. The database constructed suggest the existence of
bijections between certain classes of -algebras and well-known combinatorial
objects. On the one hand, we prove that Bell numbers enumerate isomorphism
classes of finite linear -algebras. On the other hand, we also prove that
finite regular -algebras are in bijective correspondence with
infinite-dimensional Young diagrams.Comment: 17 pages, 3 tables, 2 figures. Postprint versio
Electric dipole and magnetic quadrupole moments of the boson via a CP-violating vertex in effective Lagrangians
The possibility of nonnegligible electric dipole ()
and magnetic quadrupole () moments induced by the most general
vertex is examined via the effective Lagrangian technique. It is assumed
that new heavy fermions induce an anomalous CP-odd component of the
vertex, which can be parametrized by an -invariant
dimension-six operator. This anomalous contribution, when combined with the
standard model CP-even contribution, lead to CP-odd electromagnetic properties
of the boson, which are characterized by the form factors and . It is found that is divergent, whereas is finite,
which reflects the fact that the latter cannot be generated at the one-loop
level in any renormalizable theory. Assuming reasonable values for the unknown
parameters, we found that e-cm,
which is eight orders of magnitude larger than the SM prediction and close to
the upper bound derived from the neutron electric dipole moment. The estimated
size of the somewhat less-studied moment is of the order of
e-cm^2, which is fifteen orders of magnitude above the SM
contribution.Comment: 7 pages, 6 figures, REVTEX styl
CP-odd static electromagnetic properties of the W gauge boson and the t quark via the anomalous tbW coupling
In the framework of the electroweak chiral Lagrangian, the one-loop induced
effects of the anomalous coupling, which includes both left- and
right-handed complex components, on the static electromagnetic properties of
the boson and the quark are studied. The attention is focused mainly on
the CP-violating electromagnetic properties. It is found that the
anomalous coupling can induce both CP-violating moments of the boson,
namely, its electric dipole () and magnetic quadrupole
() moments. As far as the quark is concerned, a potentially
large electric dipole moment can arise due to the anomalous
coupling. The most recent bounds on the left- and right-handed parameters from
meson physics lead to the following estimates e-cm and e-cm, which
are 7 and 14 orders of magnitude larger than the standard model (SM)
predictions, whereas may be as large as e-cm, which is about 8
orders of magnitude larger than its SM counterpart.Comment: This paper has been merged with hep-ph/0612171 for publication in
Physical Review
Effective Lagrangian approach to fermion electric dipole moments induced by a CP--violating vertex
The one--loop contribution of the two CP--violating components of the
vertex,
and $(\tilde{\lambda}_\gamma / m^2_W)W^+_{\mu \nu}W^{-\nu}_{\
\rho}\tilde{F}^{\rho \mu}SU_L(2)\times
U_Y(1)\tilde{\kappa}_\gamma|\tilde{\kappa}_\gamma| <5.2\times 10^{-5}\tilde{\lambda}_\gamma|\tilde{\lambda}_\gamma|<1.9\times10^{-2}\tilde{\kappa}_\gamma\tilde{\lambda}_\gammaW|d_W|<6.2\times 10^{-21} e\cdot cm|\tilde{Q}_W|<3\times 10^{-36} e\cdot cm^2 10^{-20} e\cdot cm10^{-21} e\cdot cmtb$ quarks, respectively.Comment: 14 pages and 2 figure
Braided racks, Hurwitz actions and Nichols algebras with many cubic relations
We classify Nichols algebras of irreducible Yetter-Drinfeld modules over
groups such that the underlying rack is braided and the homogeneous component
of degree three of the Nichols algebra satisfies a given inequality. This
assumption turns out to be equivalent to a factorization assumption on the
Hilbert series. Besides the known Nichols algebras we obtain a new example. Our
method is based on a combinatorial invariant of the Hurwitz orbits with respect
to the action of the braid group on three strands.Comment: v2: 35 pages, 6 tables, 14 figure
Super-conservative interpretation of muon g-2 results applied to supersymmetry
The recent developments in theory and experiment related to the anomalous
magnetic moment of the muon are applied to supersymmetry. We follow a very
cautious course, demanding that the supersymmetric contributions fit within
five standard deviations of the difference between experiment and the standard
model prediction. Arbitrarily small supersymmetric contributions are then
allowed, so no upper bounds on superpartner masses result. Nevertheless,
non-trivial exclusions are found. We characterize the substantial region of
parameter space ruled out by this analysis that has not been probed by any
previous experiment. We also discuss some implications of the results for
forthcoming collider experiments.Comment: 10 pages, latex, 3 fig
Characterization of variable EST SSR markers for Norway spruce (Picea abies L.)
<p>Abstract</p> <p>Background</p> <p>Norway spruce is widely distributed across Europe and the predominant tree of the Alpine region. Fast growth and the fact that timber can be harvested cost-effectively in relatively young populations define its status as one of the economically most important tree species of Northern Europe. In this study, EST derived simple sequence repeat (SSR) markers were developed for the assessment of putative functional diversity in Austrian Norway spruce stands.</p> <p>Results</p> <p>SSR sequences were identified by analyzing 14,022 publicly available EST sequences. Tri-nucleotide repeat motifs were most abundant in the data set followed by penta- and hexa-nucleotide repeats. Specific primer pairs were designed for sixty loci. Among these, 27 displayed polymorphism in a testing population of 16 <it>P. abies </it>individuals sampled across Austria and in an additional screening population of 96 <it>P. abies </it>individuals from two geographically distinct Austrian populations. Allele numbers per locus ranged from two to 17 with observed heterozygosity ranging from 0.075 to 0.99.</p> <p>Conclusions</p> <p>We have characterized variable EST SSR markers for Norway spruce detected in expressed genes. Due to their moderate to high degree of variability in the two tested screening populations, these newly developed SSR markers are well suited for the analysis of stress related functional variation present in Norway spruce populations.</p
Very light CP-odd scalar in the Two-Higgs-Doublet Model
We show that a general two-Higgs-doublet model (THDM) with a very light
CP-odd scalar (A) can be compatible with the rho parameter, Br(b --> s\gamma),
R_b, A_b, (g-2) of muon, Br(Upsilon --> A gamma), and the direct search via the
Yukawa process at LEP. For its mass around 0.2 GeV, the muon (g-2) and
Br(Upsilon --> A \gamma) data require tan(beta) to be about 1. Consequently, A
can behave like a fermiophobic CP-odd scalar and predominantly decay into a
photon pair ("gamma gamma"), which registers in detectors of high energy
collider experiments as a single photon signature when the momentum of A is
large. We compute the partial decay width of Z --> A A A and the production
rate of f \bar{f} --> Z A A --> Z +"gamma gamma", f^' {\bar f} --> W^{\pm} A A
--> W^\pm + "gamma gamma" and f \bar f --> H^+ H^- --> W^+ W^- A A --> W^+ W^-
+ "gamma gamma" at high energy colliders such as LEP, Tevatron, LHC, and future
Linear Colliders. Other production mechanisms of a light A, such as gg --> h
--> AA --> "gamma gamma", are also discussed.Comment: Some improvementes, references updated, 3 new figures, one new
appendix, abstract and conclusions unchaged. Version to appear in Physical
Review
Muon anomalous magnetic dipole moment in supersymmetric theories
We study the muon anomalous magnetic dipole moment in supersymmetric
theories. The impact of the recent Brookhaven E821 experimental measurement on
both model-independent and model-dependent supersymmetric parameter spaces is
discussed in detail. We find that values of tan\beta as low as 3 can be
obtained while remaining within the E821 one-sigma bound. This requires a light
smuon; however, we show that, somewhat surprisingly, no model-independent bound
can be placed on the mass of the lightest chargino for any tan\beta greater
than or equal to 3. We also show that the maximum contributions to the
anomalous magnetic moment are insensitive to CP-violating phases. We provide
analyses of the supersymmetric contribution to the muon anomalous magnetic
moment in dilaton-dominated supergravity models and gauge-mediated
supersymmetry-breaking models. Finally, we discuss how other phenomena, such as
, relic abundance of the lightest superpartner, and the Higgs
mass may be correlated with the anomalous magnetic moment, but do not
significantly impact the viability of a supersymmetric explanation, or the mass
limits obtainable on smuons and charginos.Comment: 28 page
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