No abstract

In this study, we have prepared cobalt selenide (CoSe2) due to its useful aspects from a catalysis point of view such as abundant active sites from Se edges, and significant stability in alkaline conditions.

The measured charged particle $$p_T$$ p T spectra in proton-proton collisions obtained by the CMS experiment at CERN is compared with the simulation results of EPOS–LHC and Pythia8.24 models at 7 TeV center-of-mass energy. The Pythia8.24 model describes the experimental data very well, particularly in the high $$p_T$$ p T region. The model also predicts the $$p_T$$ p T spectra for $$|$$ | $$\eta $$ η $$|$$ | < 2.4 at 0 $$\le $$ ≤ $$p_T$$ p T $$\le $$ ≤ 6 $$\text {GeV/}c$$ GeV/ c . The EPOS–LHC model underpredicts the $$p_T$$ p T spectra from 0.1 to 2 $$\text {GeV/}c$$ GeV/ c in all $$\eta $$ η bins for about 20% and the $$p_T$$ p T spectrum from 0.1 to 4.2 $$\text {GeV/}c$$ GeV/ c for $$|$$ | $$\eta $$ η $$|$$ | < 2.4 by about 15% while reasonably predicts well for $$p_T$$ p T > 4.2 $$\text {GeV/}c$$ GeV/ c within the experimental errors. Furthermore, to get information about collective properties of the hadronic matter, modified Hagedorn function with embedded transverse flow velocity and thermodynamically consistent Tsallis distribution functions are used to fit the experimental data and simulated results. The values of $$\chi ^2/ndf$$ χ 2 / n d f show that the functions fit the data and simulation results well. The parameter extracted by the functions: $$\beta _T$$ β T , $$T_0$$ T 0 , and $$T_{eff}$$ T eff decreases with increasing $$\eta $$ η . The decrease in $$\beta _T$$ β T with increasing $$\eta $$ η is due to the large energy deposition in lower rapidity bins producing rapid expansion due to large pressure gradient resulting quick expansion of the fireball. Similarly, large energy transfer in the lower pseudo-rapidity bin results in higher degree of excitation of the system which results larger values of $$T_0$$ T 0 and $$T_{eff}$$ T eff . The values of the fit constant $$N_0$$ N 0 increase with $$\eta $$ η where the values of $$N_0$$ N 0 extracted from Pythia8.24 are closer to the data than the EPOS–LHC model. The Pythia8.24 model has better prediction than the EPOS–LHC model which might be connected to its flow-like features and color re-connections resulting from different Parton interactions in the initial and final state.

We analyze the transverse momentum (pT ) spectra, 1=Nev[(1/2pT ) d2N/dydpT ], of kaon, proton, deuteron and triton in different centrality events in gold-gold (Au-Au) collisions at Relativistic Heavy Ion Collisions (RHIC) by Hagedorn thermal model and extracted the excitation function of effective temperature, kinetic freeze-out volume, initial temperature and kinetic freeze-out temperature. We perceived that the effective temperature, initial temperature and kinetic freeze-out temperature sharply increases from 7.7 GeV to 14.5 GeV and then remain static from 14.5-39 GeV, and this consistency may disclose that the onset energy of the phase transition of partial deconfinement and the whole deconfinement are 14.5 and 39 GeV respectively. The kinetic freeze-out volume and mean transverse momentum grows with the rise of collision energy. Furthermore, the different extracted temperatures are observed in the order of time evolution of the interacting system, and they (as well as kinetic freeze-out volume) have an increasing trend from peripheral to central collisions. We also observed the mass dependence of the effective temperature and kinetic freeze-out volume where former increases while the later decreases for heavier particles, which indicates the early freeze-out of the heavier particles.

No abstract