85 research outputs found
Type-III two Higgs doublet model plus a pseudoscalar confronted with , muon and dark matter
In this work, we introduce an extra singlet pseudoscalar into the Type-III
two Higgs doublet model (2HDM) which is supposed to solve a series of problems
in the modern particle-cosmology. With existence of a light pseudoscalar, the
excess measured at CMS and as well as the
anomaly could be simultaneously explained within certain parameter spaces that
can also tolerate the data on the flavor-violating processes
and Higgs decay gained at LHC. Within the same
parameter spaces, the DM relic abundance is well accounted. Moreover, the
recently observed Galactic Center gamma ray excess(GCE) is proposed to realize
through dark matter(DM) pair annihilations, and in this work, the scenario of
the annihilation being mediated by the pseudoscalar is also addressed.Comment: 14 pages, 8 figures, version to appear in NP
Exploring open-charm decay mode of charmonium-like state
The newly observed exotic states are definitely not in the standard
structures, thus their existence composes a challenge to our
understanding on the fundamental principles of hadron physics. Therefore the
studies on their decay patterns which are determined by the non-perturbative
QCD will definitely shed light on the concerned physics. Generally the
four-quark states might be in a molecular state or tetraquark or their mixture.
In this work, we adopt the suggestion that is a charmonium-like
tetraquark made of a diquark and an anti-diquark. If it is true, its favorable
decay mode should be decaying into an open-charm baryon pair, since
such a transition occurs via strong interaction and is super-OZI-allowed. In
this work, we calculate the decay width of
in the framework of the quark pair creation (QPC) model. Our numerical results
on the partial width computed in the tetraquark configuration coincide with the
Belle data within a certain error tolerance.Comment: 8 pages, 4 figures, 1 table. Accepted by Eur. Phys. J.
The algebraic geometry of perfect and sequential equilibrium: an extension
We extend the generic equivalence result of Blume and Zame (Econometrica 62: 783-794, 1994) to a broader context of perfectly and sequentially rational strategic behavior (including equilibrium and nonequilibrium behavior) through a unifying solution concept of "mutually acceptable course of action" (MACA) proposed by Greenberg et al. (2009). As a by-product, we show, in the affirmative, Dekel et al.'s (1999) conjecture on the generic equivalence between the sequential and perfect versions of rationalizable self-confirming equilibrium. JEL Classification: C70, C7
MIMO Interference Channels Assisted by Reconfigurable Intelligent Surfaces: Mutual Coupling Aware Sum-Rate Optimization Based on a Mutual Impedance Channel Model
We investigate a multi-user multiple-input multiple-output interference
network in the presence of multiple reconfigurable intelligent surfaces (RISs).
The entire system is described by using a circuit-based model for the
transmitters, receivers, and RISs. This is obtained by leveraging the
electromagnetic tool of mutual impedances, which accounts for the signal
propagation and the mutual coupling among closely-spaced scattering elements.
An iterative and provably convergent optimization algorithm that maximizes the
sum-rate of RIS-assisted multi-user interference channels is introduced.
Numerical results show that the sum-rate is enhanced if the mutual coupling
among the elements of the RISs is accounted for at the optimization stage.Comment: Article submitted for journal publicatio
Reconfigurable Intelligent Surface-Assisted Secret Key Generation in Spatially Correlated Channels
Reconfigurable intelligent surface (RIS) is a disruptive technology to
enhance the performance of physical-layer key generation (PKG) thanks to its
ability to smartly customize the radio environments. Existing RIS-assisted PKG
methods are mainly based on the idealistic assumption of an independent and
identically distributed (i.i.d.) channel model at both the base station (BS)
and the RIS. However, the i.i.d. model is inaccurate for a typical RIS in an
isotropic scattering environment and neglecting the existence of channel
spatial correlation would possibly degrade the PKG performance. In this paper,
we establish a general spatially correlated channel model and propose a new
channel probing framework based on the transmit and the reflective beamforming.
We derive a closed-form key generation rate (KGR) expression and formulate an
optimization problem, which is solved by using the low-complexity Block
Successive Upper-bound Minimization (BSUM) with Mirror-Prox method. Simulation
results show that compared to the existing methods based on the i.i.d. fading
model, our proposed method achieves about dB transmit power gain when the
spacing between two neighboring RIS elements is a quarter of the wavelength.
Also, the KGR increases significantly with the number of RIS elements while
that increases marginally with the number of BS antennas.Comment: arXiv admin note: text overlap with arXiv:2207.1175
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