3 Search Results

The procedure for the energy calibration of the high granularity electromagnetic calorimeter PHOS of the ALICE experiment is presented. The methods used to perform the relative gain calibration, to evaluate the geometrical alignment and the corresponding correction of the absolute energy scale, to obtain the nonlinearity correction coefficients and finally, to calculate the time-dependent calibration corrections, are discussed and illustrated by the PHOS performance in proton-proton (pp) collisions at √s = 13 TeV. After applying all corrections, the achieved mass resolutions for π⁰ and η mesons for p_T > 1.7 GeV/c are σ_m^π0 = 4.56 ± 0.03 MeV/c² and σ_m^ηmore » = 15.3 ± 1.0 MeV/c², respectively.« less

Here, a highly granular electromagnetic calorimeter with scintillator strip readout is being developed for future linear collider experiments. A prototype of 21.5 $X_0$ depth and $180\times 180{\mathrm{mm}}^2$ transverse dimensions was constructed, consisting of 2160 individually read out $10\times 45\times 3{\mathrm{mm}}^3$ scintillator strips. This prototype was tested using electrons of 2–32 $\mathrm{Ge}\mathrm{V}$ at the Fermilab Test Beam Facility in 2009. Deviations from linear energy response were less than 1.1%, and the intrinsic energy resolution was determined tomore » be $(12.5\pm 0.1\left(\mathrm{stat.}\right)\pm 0.4\left(\mathrm{syst.}\right))\text{\%}/\sqrt{E\left[\mathrm{Ge}\mathrm{V}\right]}\oplus (1.2\pm 0.1{\left(\mathrm{stat.}\right)}_{-0.7}^{+0.6}\left(\mathrm{syst.}\right))\text{\%}$, where the uncertainties correspond to statistical and systematic sources, respectively.« less

We present here the first statistically meaningful results from two-$${K}_{s}^{0}$$ interferometry in heavy-ion collisions at $$\sqrt{{s}_{\mathit{NN}}}=200$$ GeV. A model that takes the effect of the strong interaction into account has been used to fit the measured correlation function. The effects of single and coupled channels were explored. At the mean transverse mass $${\langle}{m}_{T}{\rangle}=1.07$$ GeV, we obtain the values $$R=4.09\pm{}0.46(\mathrm{stat})\pm{}0.31(\mathrm{sys})$$ fm and $${\lambda}=0.92\pm{}0.23(\mathrm{stat})\pm{}0.13(\mathrm{sys})$$, where $$R$$ and λ are the invariant radius and chaoticity parameters, respectively. The results are qualitatively consistent with $${m}_{T}$$ systematics established with pions in a scenario characterized by a strong collective flow.