Modern Physics Letters A

About 30 years ago, I was among several students mentored by Professor Yang at Stony Brook to enter the field of particle accelerator physics. Since then, I have been fortunate to work on several major accelerator projects in USA and in China, guided and at times directly supported by Professor Yang. The field of accelerator physics is flourishing worldwide both providing indispensable tools for fundamental physics research and covering an increasingly wide spectrum of applications beneficial to our society.

From dispersion relation approach, a formalism that describes final state interaction among three particles in a coupled-channel system is presented. Different representations of coupled-channel three-body formalism for spinless particles in both initial and final states are derived.

The left–right twin Higgs (LRTH) model, which adds an extra set of the Higgs to the Standard Model (SM) Higgs spectrum by the left–right discrete symmetry, is one of the phenomenological realization of the new physics models to solve the little hierarchy problem. In this paper, we will, in the $R_{\xi }$ gauge, give the complete Lagrangians in this new physics model and then apply them to the processes $gg\to h$ and $h\to \gamma \gamma$.

In the previous work [A. P. Balachandran and S. Vaidya, Eur. Phys. J. Plus 128, 118 (2013)], we have argued that the algebra of non-Abelian superselection rules is spontaneously broken to its maximal Abelian subalgebra, that is, the algebra generated by its completing commuting set (the two Casimirs, isospin and a basis of its Cartan subalgebra). In this paper, alternative arguments confirming these results are presented. In addition, Lorentz invariance is shown to be broken in quantum chromodynamics (QCD), just as it is in quantum electrodynamics (QED). The experimental consequences of these results include fuzzy mass and spin shells of coloured particles like quarks, and decay life times which depend on the frame of observation [D. Buchholz, Phys. Lett. B 174, 331 (1986); D. Buchholz and K. Fredenhagen, Commun. Math. Phys. 84, 1 (1982; J. Fröhlich, G. Morchio and F. Strocchi, Phys. Lett. B 89, 61 (1979); A. P. Balachandran, S. Kürkçüoğlu, A. R. de Queiroz and S. Vaidya, Eur. Phys. J. C 75, 89 (2015); A. P. Balachandran, S. Kürkçüoğlu and A. R. de Queiroz, Mod. Phys. Lett. A 28, 1350028 (2013)].

In a paper under preparation, these results are extended to the ADM Poincaré group and the local Lorentz group of frames. The renormalisation of the ADM energy by infrared gravitons is also studied and estimated.

In this paper, we study thermal stability of an exotic fluid known as generalized cosmic Chaplygin gas (GCCG). We evaluate different physical parameters and examine how this fluid describes accelerated expansion of the universe. The stability conditions are formulated from thermodynamics which indicate that the respective fluid is stable adiabatically but it cannot be checked under isothermal condition.

A simple extension of the Standard Model (SM), based on the gauge group $\mathrm{\text{SU}}{(3)}_C\otimes \mathrm{\text{SU}}{(3)}_L\otimes \mathrm{\text{U}}{(1)}_Y$ with $Y$ being the hypercharge, is considered. We show that, by imposing an approximate global $\mathrm{\text{SU}}{(2)}_L\times \mathrm{\text{SU}}{(2)}_R$ custodial symmetry at the SM energy scale, the $Z-Z^{\prime }$ mixing is absent at tree level and the value of the $\rho$ parameter can be kept close to one. Tree-level flavor-changing neutral currents (FCNCs) are also reduced to three particles, namely $Z^{\prime }$, a CP-odd Higgs and a CP-even Higgs. The model predicts new leptons with electric charges of ±1/2e and new quarks with ±1/6e charges as well as new gauge and scalar bosons with ±1/2e charges. Electric charge conservation requires that one of them must be stable. Their masses are unfortunately free parameters.

In this paper, one presents a naive parametrization to $pp$ and $\bar{p}p$ total cross-sections. The main goal of this parametrization is to study the possible fractal structure present in the total cross-section. The result of the fitting procedure shows two different fractal dimensions: a negative (low-energies) and a positive (high-energies). The negative fractal dimension represents the emptiness of the total cross-section structure and the positive represents the filling up process with the energy increase. Hence, the total cross-section presents a multifractal behavior. At low-energies, the odderon exchange may be associated with the negative fractal dimension and at high-energies, the pomeron may be associated with the positive fractal dimension. Therefore, the exchange of odderons and pomerons may be viewed as a transition from a less well-defined to a more well-defined internal structure, depending on the energy.