Light Dark Matter Search and Spectroscopy -- Brief Review and An Experimental Technique.

A brief review of light dark matter particles and their spectroscopy is presented, specifically aimed at understanding the interaction mechanisms of axion and Axion-Like Particles (ALPs) with matter and an interim proposal and some ideas for possible detection of these evasive particles. In order to venture into the highly challenging spectral regions and extremely weak signals involved with these searches (especially for the DFSZ axions), a different scheme is proposed departing from the conventional resonant cavity mass scan and heterodyne detection methods. We aim to look for a fixed mass axionic field and concentrate our search at the corresponding resonant frequency and its higher harmonics using a simple phase-sensitive dc detection method, which could possibly be helpful in substantially reducing both the hardware, experiment complexities and long run times. The probable mass range suggested in the model presented here begins with 22.5microeV, corresponding to a resonant frequency of 5.4GHz, going all the way to its two multiples of 90 and 112.5microeV (corresponding to 24.3 and 27.0GHz frequencies, respectively), with high probability of finding an axion or ALP around these mass values. We present a comprehensive measurement strategy and spectroscopy technique based upon this model which revolves around a three-stage amplification and phase-sensitive detection scheme to maximize and detect a resonant axionic coupling to the U(1) fields under a coherent Primakoff effect interaction. The feasibility of proposed scheme is demonstrated with some calculations, simulations and preliminary tests. This experimental technique and ideas reported here have significant potential to be developed into an extremely sensitive narrow-range dark matter axion/ALP spectroscopy experiment.