549 research outputs found
Charged Higgs production from polarized top-quark decay in the 2HDM considering the general-mass variable-flavor-number scheme
Charged Higgs bosons are predicted by some non-minimal Higgs
scenarios, such as models containing Higgs triplets and two-Higgs-doublet
models, so that the experimental observation of these bosons would indicate
physics beyond the Standard Model. In the present work, we introduce a new
channel to indirect search for the charged Higgses through the hadronic decay
of polarized top quarks where a top quark decays into a charged Higgs and
a bottom-flavored hadron via the hadronization process of the produced
bottom quark, . To obtain the energy
spectrum of produced -hadrons we present, for the first time, an analytical
expression for the corrections to the differential decay
width of the process in the presence of a massive b-quark
in the General-Mass Variable-Flavor-Number Scheme (GM-VFNS). We find that the
most reliable predictions for the B-hadron energy spectrum are made in the
GM-VFN scheme, specifically, when the Type-II 2HDM scenario is concerned
Next-to-leading order corrections to the spin-dependent energy spectrum of hadrons from polarized top quark decay in the general two Higgs doublet model
In recent years, searches for the light and heavy charged Higgs bosons have
been done by the ATLAS and the CMS collaborations at the Large Hadron Collider
(LHC) in proton-proton collision. Nevertheless, a definitive search is a
program that still has to be carried out at the LHC. The experimental
observation of charged Higgs bosons would indicate physics beyond the Standard
Model. In the present work, we study the scaled-energy distribution of
bottom-flavored mesons () inclusively produced in polarized top quark decays
into a light charged Higgs boson and a massless bottom quark at next-to-leading
order in the two-Higgs-doublet model; . This
spin-dependent energy distribution is studied in a specific helicity coordinate
system where the polarization vector of the top quark is measured with respect
to the direction of the Higgs momentum. The study of these energy distributions
could be considered as a new channel to search for the charged Higgs bosons at
the LHC. For our numerical analysis and phenomenological predictions, we
restrict ourselves to the unexcluded regions of the MSSM
parameter space determined by the recent results of the CMS \cite{CMS:2014cdp}
and ATLAS \cite{TheATLAScollaboration:2013wia} collaborations.Comment: 10 pages, 6 figures. arXiv admin note: text overlap with
arXiv:1611.0801
Dynamical Systems on Hilbert C*-Modules
We investigate the generalized derivations and show that every generalized
derivation on a simple Hilbert -module either is closable or has a dense
range. We also describe dynamical systems on a full Hilbert -module
over a -algebra as a one-parameter group of
unitaries on and prove that if
is a dynamical system, where denotes the set of all unitary
operator on , then we can correspond a -dynamical system
on such that if and are the
infinitesimal generators of and respectively, then
is a -derivation.Comment: 7 pages, minor changes, to appear in Bull. Iranian Math. So
Indirect search for light charged Higgs bosons through the dominant semileptonic decays of top quark
In this work we introduce a new channel to indirect search for the light
charged Higgs bosons, which are predicted in several extensions of the standard
model (SM) such as the two-Higgs-doublet models (2HDMs). We calculate the
QCD radiative corrections to the energy distribution of
bottom- and charmed-flavored hadrons () produced in the dominant decays of
the polarized top quark in the 2HDM, i.e. . %This analysis is studied in a
specific helicity coordinate system where the polarization vector of the top
quark is evaluated with respect to the momentum direction of the bottom quark.
Generally, the energy distribution of hadrons is governed by the unpolarized
rate and the polar and the azimuthal correlation functions which are related to
the density matrix elements of the decay . In our
proposed channel, any deviation of the -meson energy spectrum from its
corresponding SM predictions can be considered as a signal for the existence of
charged Higgs at the LHC. We also calculate, for the first time, the azimuthal
correlation rate at next-to-leading order which vanishes at the
Born level.Comment: 10 pages, 5 figures, published in NPB 932 (2018) 50
Measuring Perceived Trust in XAI-Assisted Decision-Making by Eliciting a Mental Model
This empirical study proposes a novel methodology to measure users' perceived
trust in an Explainable Artificial Intelligence (XAI) model. To do so, users'
mental models are elicited using Fuzzy Cognitive Maps (FCMs). First, we exploit
an interpretable Machine Learning (ML) model to classify suspected COVID-19
patients into positive or negative cases. Then, Medical Experts' (MEs) conduct
a diagnostic decision-making task based on their knowledge and then prediction
and interpretations provided by the XAI model. In order to evaluate the impact
of interpretations on perceived trust, explanation satisfaction attributes are
rated by MEs through a survey. Then, they are considered as FCM's concepts to
determine their influences on each other and, ultimately, on the perceived
trust. Moreover, to consider MEs' mental subjectivity, fuzzy linguistic
variables are used to determine the strength of influences. After reaching the
steady state of FCMs, a quantified value is obtained to measure the perceived
trust of each ME. The results show that the quantified values can determine
whether MEs trust or distrust the XAI model. We analyze this behavior by
comparing the quantified values with MEs' performance in completing diagnostic
tasks.Comment: Accepted in IJCAI 2023 Workshop on Explainable Artificial
Intelligence (XAI
Measuring Perceived Trust in XAI-Assisted Decision-Making by Eliciting a Mental Model
This empirical study proposes a novel methodology to measure users' perceived trust in an Explainable Artificial Intelligence (XAI) model. To do so, users' mental models are elicited using Fuzzy Cognitive Maps (FCMs). First, we exploit an interpretable Machine Learning (ML) model to classify suspected COVID-19 patients into positive or negative cases. Then, Medical Experts' (MEs) conduct a diagnostic decision-making task based on their knowledge and then prediction and interpretations provided by the XAI model. In order to evaluate the impact of interpretations on perceived trust, explanation satisfaction attributes are rated by MEs through a survey. Then, they are considered as FCM's concepts to determine their influences on each other and, ultimately, on the perceived trust. Moreover, to consider MEs' mental subjectivity, fuzzy linguistic variables are used to determine the strength of influences. After reaching the steady state of FCMs, a quantified value is obtained to measure the perceived trust of each ME. The results show that the quantified values can determine whether MEs trust or distrust the XAI model. We analyze this behavior by comparing the quantified values with MEs' performance in completing diagnostic tasks
Ameliorative effects of salicylic acid on mineral concentrations in roots and leaves of two grapevine (Vitis vinifera L.) cultivars under salt stress
Salicylic acid (SA) acts as an endogenous signal molecule, synchronizing plant responses under abiotic stress and a component of tolerance in plants. The current study investigates the effects of SA on mineral nutrient concentrations in two grapevine (Vitis vinifera L.) cultivars, 'Qarah Shani' and 'Thompson Seedless' under NaCl stress. Grapevine rooted cuttings were planted in pots, containing a mixture of perlite and cocopeat (1:1 v/v) and placed in an open hydroponic system. Plants were exposed to five levels of salinity 0, 25, 50, 75 and 100 mM NaCl and four levels of SA 0, 100, 200 and 300 mg∙L-1. Results indicated that foliar spray with SA improved nutrient uptake by grape roots. Plant’s leaves and roots Na+ and Cl- contents increased significantly, and NO- 3-N, K+, Na+, Ca2+, Mg2+, Zn2+, Fe2+ and also K+/Na+ selectivity ratios decreased in both cultivars in response to salt treatments. Application of SA significantly reduced Na+ and Cl- accumulation in leaves and roots in both cultivars and it increased NO3-N, K+, Ca2+, Mg2+, Zn2+ and Fe2+ contents under NaCl stress. Therefore, SA could mitigate the detrimental effects of salinity on accumulation of harmful ions and improve the absorption of essential and beneficial elements in grapevine under salinity.
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