Physics implication from higher weak isospin decomposition

The $SU(3)_L\otimes U(1)_X$ symmetry actually studied is directly broken to the electroweak symmetry $SU(2)_L\otimes U(1)_Y$ by a Higgs triplet, predicting a relevant new physics at TeV scale. This work argues, by contrast, that the higher weak isospin $SU(3)_L$ might be broken at a high energy scale, much beyond $1$ TeV, by a Higgs octet to an intermediate symmetry $SU(2)_L\otimes U(1)_{T_8}$ at TeV, before the latter $U(1)_{T_8}$ recombined with $U(1)_X$ defines (i.e., broken to) $U(1)_Y$ by a Higgs singlet. The new physics coupled to $SU(3)_L$ breaking phase is decoupled, whereas what remains is a novel family-nonuniversal abelian model, $U(1)_{T_8}\otimes U(1)_X$, significantly overhauling the standard model as well as yielding consistent results for neutrino mass, dark matter, $W$-mass anomaly, and FCNC, differently from the usual 3-3-1 model.Comment: 31 pages, 4 figures, 3 tables; Revised version with references added; Published in EPJ

Asymmetric matter from B−LB-L symmetry breaking

The present matter content of our universe may be governed by a $U(1)_{B-L}$ symmetry -- the simplest gauge completion of the seesaw mechanism which produces small neutrino masses. The matter parity results as a residual gauge symmetry, implying dark matter stability. The Higgs field that breaks the $B-L$ charge inflates the early universe successfully and then decays to right-handed neutrinos, which reheats the universe and generates both normal matter and dark matter manifestly.Comment: 21 pages; substantially improved with references and figures added; matches published version in EPJ

BER analysis of amplify-and-forward relaying FSO systems using APD receiver over strong atmospheric turbulence channels

In this paper, we theoretically analyze the performance of amplify-and-forward (AF) serial relaying free-space optical (FSO) systems using avalanche photodiodes (APD) and subcarrier quadrature amplitude modulation (SC-QAM) over strong atmospheric turbulence channels modelled by gamma-gamma distribution. Closed-form expression for average bit error rate (BER) of system is theoretically derived talking into account APD shot noise, thermal noise as well as the impact of atmospheric loss and turbulence. The numerical results show that using AF relay stations can extend the transmission distance and help to improve performance of FSO system significantly when compared with the direct transmission. Moreover, the selection of APD gain value is indispensable to the system performance. The proposed system could be achieved the best performance by selecting an optimal APD gain value. In addition, the optimal value of APD gain also significantly depends on various conditions, such as link distance, the number of relay stations and APD receiver noise

Can the Higgs field feel a dark force?

We argue that if an electroweak Higgs field possesses a dark gauge charge responsible for dark matter stability, the $W$-boson mass deviation is properly induced, besides appropriately generated neutrino masses. We examine a simple model in which the usual Higgs doublet plays the role but dark matter candidates are somewhat input by ad hoc. We look for a realistic model that fully realizes such observation, thereby neutrino mass and dark matter are naturally supplied by a dark non-abelian gauge symmetry.Comment: 22 pages, 4 figures, 3 table

Abelian charge inspired by family number

Quark has an electric charge either $-1/3$ or $2/3$ and a baryon number $1/3$, where the divisions $3$'s match the color number. Although the electric charge and the baryon number have a nature distinct from the color charge, the matching is necessary for the standard model or a relevant $B-L$ extension consistent at quantum level, since the relevant anomaly $[SU(2)_L]^2U(1)_A$ for $A=Y$ or $B-L$ must vanish. If elementary particles have a new $U(1)$ charge differently from $A$, such anomaly is not cancelled for each family. However, if we demand that the anomaly is cancelled over all families, this relates the color number to the family number instead of the electric charge and baryon number, and interestingly the family number guides us to a novel $U(1)$ theory. We will discuss the implication of this theory for neutrino mass, recent $W$-boson mass anomaly, FCNC, and particle colliders.Comment: 20 pages, 2 figure

Phenomenology of a minimal extension of the standard model with a family-dependent gauge symmetry

We consider a gauge symmetry extension of the standard model given by $SU(3)_C\otimes SU(2)_L\otimes U(1)_X\otimes U(1)_N\otimes Z_2$ with minimal particle content, where $X$ and $N$ are family dependent but determining the hypercharge as $Y=X+N$, while $Z_2$ is an exact discrete symmetry. In our scenario, $X$ (while $N$ is followed by $X-Y$) and $Z_2$ charge assignments are inspired by the number of fermion families and the stability of dark matter, as observed, respectively. We examine the mass spectra of fermions, scalars, and gauge bosons, as well as their interactions, in presence of a kinetic mixing term between $U(1)_{X,N}$ gauge fields. We discuss in detail the phenomenology of the new gauge boson and the right-handed neutrino dark matter stabilized by $Z_2$ conservation. We obtain parameter spaces simultaneously satisfying the recent CDF $W$-boson mass, electroweak precision measurements, particle colliders, as well as dark matter observables, if the kinetic mixing parameter is not necessarily small.Comment: 32 pages, 4 figures, 5 tables; Matches published version in PR

Misalignment fading effects on the ACC performance of relay-assisted MIMO/FSO systems over atmospheric turbulence channels

The continuous development of internet of things (IoT) technology enables many devices to be interconnected through the external environment. Meanwhile, 5G technology provides an enhanced quality of services with high data transmission rates, requiring IoT implementation in the 5G architecture. Free-space optical communication (FSO) is considered a promising technique that can provide high-speed communication links, so FSO is an optimal choice for wireless networks to fulfill the full potential of 5G technology, providing speeds of 100 Gb/s or more. By implementing 5G features in IoT, IoT coverage and performance will be enhanced by using FSO models. Therefore, the paper proposed and investigated the multiple-input and multiple-output/free-space optical communication (MIMO/FSO) model using subcarrier quadrature amplitude modulation (SC-QAM) and relay stations over atmospheric turbulence channels by log-normal and gamma-gamma distribution under different turbulence conditions. The performance is examined based on the average channel capacity (ACC), which is expressed in terms of average spectral efficiency (ASE) parameters while changing the different parameters of the model. The mathematical formulas of ACC for atmospheric turbulence cases are calculated and discussed the influence of turbulence strength, the different number of relay stations, misalignment effects, and different MIMO configurations