250 research outputs found
Determining the top-antitop and Couplings of a Neutral Higgs Boson of Arbitrary CP Nature at the NLC
The optimal procedure for extracting the coefficients of different components
of a cross section which takes the form of unknown coefficients times functions
of known kinematical form is developed. When applied to \epem\to t\anti
t+Higgs production at \rts=1\tev and integrated luminosity of 200\fbi, we
find that the t\anti t\toHiggs CP-even and CP-odd couplings and, to a lesser
extent, the Higgs (CP-even) coupling can be extracted with reasonable
errors, assuming the Higgs sector parameter choices yield a significant
production rate. Indeed, the composition of a mixed-CP Higgs eigenstate can be
determined with sufficient accuracy that a SM-like CP-even Higgs boson can be
distinguished from a purely CP-odd Higgs boson at a high level of statistical
significance, and vice versa.Comment: 8 pages, full postscript file also available via anonymous ftp at
ftp://ucdhep.ucdavis.edu/gunion/eetottbh.p
Online Deep Learning from Doubly-Streaming Data
This paper investigates a new online learning problem with doubly-streaming data, where the data streams are described by feature spaces that constantly evolve, with new features emerging and old features fading away. A plausible idea to deal with such data streams is to establish a relationship between the old and new feature spaces, so that an online learner can leverage the knowledge learned from the old features to better the learning performance on the new features. Unfortunately, this idea does not scale up to high-dimensional multimedia data with complex feature interplay, which suffers a tradeoff between onlineness, which biases shallow learners, and expressiveness, which requires deep models. Motivated by this, we propose a novel OLD3S paradigm, where a shared latent subspace is discovered to summarize information from the old and new feature spaces, building an intermediate feature mapping relationship. A key trait of OLD3S is to treat the model capacity as a learnable semantics, aiming to yield optimal model depth and parameters jointly in accordance with the complexity and non-linearity of the input data streams in an online fashion. Both theoretical analysis and empirical studies substantiate the viability and effectiveness of our proposed approach. The code is available online at https://github.com/X1aoLian/OLD3S
RAD marker microarrays enable rapid mapping of zebrafish mutations
A RAD marker microarray was constructed to facilitate rapid genetic mapping of zebrafish mutations and used to localize previously unmapped mutations to genomic regions just a few centiMorgans in length
Demographic and temporal variations in immunity and condition of polar bears (\u3ci\u3eUrsus maritimus\u3c/i\u3e) from the southern Beaufort Sea
Assessing the health and condition of animals in their natural environment can be problematic. Many physiological metrics, including immunity, are highly influenced by specific context and recent events to which researchers may be unaware. Thus, using a multifaceted physiological approach and a context-specific analysis encompassing multiple time scales can be highly informative. Ecoimmunological tools in particular can provide important indications to the health of animals in the wild.We collected blood and hair samples from free-ranging polar bears (Ursus maritimus) in the southern Beaufort Sea and examined the influence of sex, age, and reproductive status on metrics of immunity, stress, and body condition during 2013–2015.We examined metrics of innate immunity (bactericidal ability and lysis) and stress (hair cortisol, reactive oxygen species, and oxidative barrier), in relation to indices of body condition considered to be short term (urea to creatinine ratio; UC ratio) and long term (storage energy and body mass index). We found the factors of sex, age, and reproductive status of the bear were critical for interpreting different physiological metrics. Additionally, the metrics of body condition were important predictors for stress indicators. Finally,many of these metrics differed between years, illustrating the need to examine populations on a longer time scale. Taken together, this study demonstrates the complex relationship between multiple facets of physiology and how interpretation requires us to examine individuals within a specific context
Modular and predictable assembly of porous organic molecular crystals
Nanoporous molecular frameworks are important in applications such as separation, storage and catalysis. Empirical rules exist for their assembly but it is still challenging to place and segregate functionality in three-dimensional porous solids in a predictable way. Indeed, recent studies of mixed crystalline frameworks suggest a preference for the statistical distribution of functionalities throughout the pores rather than, for example, the functional group localization found in the reactive sites of enzymes. This is a potential limitation for 'one-pot' chemical syntheses of porous frameworks from simple starting materials. An alternative strategy is to prepare porous solids from synthetically preorganized molecular pores. In principle, functional organic pore modules could be covalently prefabricated and then assembled to produce materials with specific properties. However, this vision of mix-and-match assembly is far from being realized, not least because of the challenge in reliably predicting three-dimensional structures for molecular crystals, which lack the strong directional bonding found in networks. Here we show that highly porous crystalline solids can be produced by mixing different organic cage modules that self-assemble by means of chiral recognition. The structures of the resulting materials can be predicted computationally, allowing in silico materials design strategies. The constituent pore modules are synthesized in high yields on gram scales in a one-step reaction. Assembly of the porous co-crystals is as simple as combining the modules in solution and removing the solvent. In some cases, the chiral recognition between modules can be exploited to produce porous organic nanoparticles. We show that the method is valid for four different cage modules and can in principle be generalized in a computationally predictable manner based on a lock-and-key assembly between modules
Ubiquitous CP violation in a top-inspired left-right model
We explore CP violation in a Left-Right Model that reproduces the quark mass
and CKM rotation angle hierarchies in a relatively natural way by fixing the
bidoublet Higgs VEVs to be in the ratio m_b:m_t. Our model is quite general and
allows for CP to be broken by both the Higgs VEVs and the Yukawa couplings.
Despite this generality, CP violation may be parameterized in terms of two
basic phases. A very interesting feature of the model is that the mixing angles
in the right-handed sector are found to be equal to their left-handed
counterparts to a very good approximation. Furthermore, the right-handed
analogue of the usual CKM phase delta_L is found to satisfy the relation
delta_R \approx delta_L. The parameter space of the model is explored by using
an adaptive Monte Carlo algorithm and the allowed regions in parameter space
are determined by enforcing experimental constraints from the K and B systems.
This method of solution allows us to evaluate the left- and right-handed CKM
matrices numerically for various combinations of the two fundamental CP-odd
phases in the model. We find that all experimental constraints may be satisfied
with right-handed W and Flavour Changing Neutral Higgs masses as low as about 2
TeV and 7 TeV, respectively.Comment: 37 pages, 13 figure
The CP-conserving two-Higgs-doublet model: the approach to the decoupling limit
A CP-even neutral Higgs boson with Standard-Model-like couplings may be the
lightest scalar of a two-Higgs-doublet model. We study the decoupling limit of
the most general CP-conserving two-Higgs-doublet model, where the mass of the
lightest Higgs scalar is significantly smaller than the masses of the other
Higgs bosons of the model. In this case, the properties of the lightest Higgs
boson are nearly indistinguishable from those of the Standard Model Higgs
boson. The first non-trivial corrections to Higgs couplings in the approach to
the decoupling limit are also evaluated. The importance of detecting such
deviations in precision Higgs measurements at future colliders is emphasized.
We also clarify the case in which a neutral Higgs boson can possess
Standard-Model-like couplings in a regime where the decoupling limit does not
apply. The two-Higgs-doublet sector of the minimal supersymmetric model
illustrates many of the above features.Comment: 54 pages, 2 tables, revtex4 format, some new material added
(including elegant forms for the three-Higgs and four-Higgs couplings) and
typographical errors fixe
Photon-Photon and Electron-Photon Colliders with Energies Below a TeV
We investigate the potential for detecting and studying Higgs bosons in and collisions at future linear colliders with energies below a TeV. Our study incorporates realistic spectra based on available laser technology, and NLC and CLIC acceleration techniques. Results include detector simulations. We study the cases of: a) a SM-like Higgs boson based on a devoted low energy machine with GeV; b) the heavy MSSM Higgs bosons; and c) charged Higgs bosons in collisions.We investigate the potential for detecting and studying Higgs bosons in and collisions at future linear colliders with energies below a TeV. Our study incorporates realistic spectra based on available laser technology, and NLC and CLIC acceleration techniques. Results include detector simulations. We study the cases of: a) a SM-like Higgs boson based on a devoted low energy machine with GeV; b) the heavy MSSM Higgs bosons; and c) charged Higgs bosons in collisions
CP Violation, Higgs Couplings, and Supersymmetry
Supersymmetric extensions of the standard model generically contain
additional sources of CP violation. We discuss how at one loop a potentially
large CP violating coupling of the lightest Higgs, h^0, to leptons is induced
in the minimal supersymmetric standard model (MSSM). The CP violating couplings
of h^0 in extensions of the MSSM, such as the next-to-minimal supersymmetric
standard model (NMSSM) are also considered. We indicate how this CP violation
might be observed; in particular a polarization-dependent production asymmetry,
in the context of a muon collider, provides a means to access this coupling
cleanly. In the MSSM, existing limits on the electric dipole moment (EDM) of
the electron, coupled with standard universality assumptions, severly
constrains any such signal. Nevertheless, extensions of the MSSM, such as the
NMSSM, allow CP-violating signals as large as 100%.Comment: 13 pages LaTeX, 4 figures (some typos fixed, discussion clarified
Measurement of the Branching Fraction for B- --> D0 K*-
We present a measurement of the branching fraction for the decay B- --> D0
K*- using a sample of approximately 86 million BBbar pairs collected by the
BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is
detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the
K*- through its decay to K0S pi-. We measure the branching fraction to be
B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}.Comment: 7 pages, 1 postscript figure, submitted to Phys. Rev. D (Rapid
Communications
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