We have initiated a search for a new type of nuclear matter, theη-mesic nucleus, using beams from the multi-GeV hadron facility, COSY at Juelich, Germany. A large acceptance scintillator detector, ENSTAR has been designed and built at BARC, Mumbai and fully assembled and tested at COSY. A test run for calibration and evaluation has been completed. In this contribution we present the design and technical details of the ENSTAR detector and how it will be used to detect protons and pions (the decay products ofη-mesic bound state). The detector is made of plastic scintillators arranged in three concentric cylindrical layers. The readout of the detectors is by means of optical fibres. The layers are used to generate ΔE –E spectra for particle identification and total energy information of stopped particles. The granularity of the detector allows for position (θ and ϕø determination making the event reconstruction kinematically complete

We have studied isospin symmetry violation in nuclear reactions by measuring simultaneously the cross-section of the following two reactionsp +d →³H π⁺ andp +d →³He π⁰. The experiment was perfomed at the cooler synchrotron accelerator COSY, Jülich at several beam energies close to the correspondingη production threshold. We also have ongoing programmes onη-nucleus final-state interaction studies viap+⁶ Li →⁷ Be +η reactions, high resolution search for dibaryonic resonances and lambda-proton final state interaction studies. The experimental details and results obtained so far are presented here

The question of possible existence ofη-mesic nuclei is quite intriguing. Answer to this question will deeply enrich our understanding ofη-nucleus interaction which is not so well-understood. We review the experimental efforts for the search ofη-mesic nuclei and describe the physics motivation behind it. We present the description of an experiment for the search ofη-nucleus bound state using the GeV proton beam, currently being performed at COSY

The elastic scattering and the ⁶He angular distributions were measured in ⁷Li + ⁷Li reaction at two energies, $E_{lab} = 20$ and 25 MeV. FRDWBA calculations have been performed to explain the measured ⁶He data. The calculations were very sensitive to the choice of the optical model potentials in entrance and exit channels. The one-step proton transfer was found to be the dominant reaction mechanism in ⁶He production.

Cross-sections for one- and multinucleon transfer reactions, namely, ⁵⁸Ni(¹²C, ¹³C), ⁵⁸Ni(¹²C, ¹¹C), ⁵⁸Ni(¹²C, ¹¹B), ⁵⁸Ni(¹²C, ¹⁰B), ⁵⁸Ni(¹²C, ¹⁰Be), ⁵⁸Ni(¹²C, ⁹Be), ⁵⁸Ni(¹²C, ⁸Be_𝑔.s.), ⁵⁸Ni(¹²C, ⁷Be), ⁵⁸Ni(¹²C, ⁷Li) and ⁵⁸Ni(¹²C, ⁶Li) have been measured at an incident energy of 60 MeV. The reaction cross-section for the corresponding transfer channels in the system ¹²C+⁵⁶Fe have also been measured under the same kinematical conditions. Angular distribution of the elastic scattering cross-section is measured at 60 MeV. The measured elastic scattering angular distributions for these two systems have been analysed using the optical model search code SFRESCO and the potential parameters are extracted. The multinucleon transfer data are analysed to obtain cross-section dependence on the number of nucleons transferred and on the ground state 𝑄-values. The transfer probabilities for multinucleon stripping are extracted. A detailed comparison in the multiparticle stripping and elastic scattering cross-sections between these two systems are made to understand the mechanism of multinucleon transfer and possible role of two extra protons in ⁵⁸Ni target nucleus as compared to the ⁵⁶Fe core.