Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userMultiplicity dependence of (multi-)strange baryons in the canonical ensemble with phase shift corrections
54
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The increase in strangeness production with charged particle multiplicity, as seen by the ALICE collaboration at CERN in p-p, p-Pb and Pb-Pb collisions, is investigated in the hadron resonance gas model taking into account interactions among hadrons using S-matrix corrections based on known phase shift analyses. Strangeness conservation is taken into account in the framework of the canonical strangeness ensemble. A very good description is obtained for the variation of the strangeness content in the final state as a function of the number of charged hadrons in the mid-rapidity region using the same fixed temperature value as obtained in the most central Pb-Pb collisions. It is shown that the number of charged hadrons is linearly proportional to the volume of the system. For small multiplicities the canonical ensemble with local strangeness conservation restricted to mid-rapidity leads to a stronger suppression of (multi-)strange baryons than seen in the data. This is compensated by introducing a global conservation of strangeness in the whole phase-space which is parameterized by the canonical correlation volume larger than the fireball volume at the mid-rapidity. The results on comparing the hadron resonance gas model with and without S-matrix corrections, are presented in detail. It is shown that the interactions introduced by the phase shift analysis via the S-matrix formalism are essential for a better description of the yields data.
rate research
Read More
The transverse momentum ($p_{rm T}$) spectra in proton-proton collisions at $sqrt{s}$ = 7 TeV, measured by the ALICE experiment at the LHC are analyzed with a thermodynamically consistent Tsallis distribution. The information about the freeze-out surface in terms of freeze-out volume, temperature and the non-extenisivity parameter, $q$, for $K^{0}_{S}$, $Lambda+bar{Lambda}$, $Xi^{-}+bar{Xi}^{+}$ and $Omega^{-}+bar{Omega}^{+}$ are extracted by fitting the $p_{rm T}$ spectra with Tsallis distribution function. The freeze-out parameters of these particles are studied as a function of charged particle multiplicity density ($dN_{ch}/deta$). In addition, we also study these parameters as a function of particle mass to see any possible mass ordering. The strange and multi-strange particles show mass ordering in volume, temperature, non-extensive parameter and also a strong dependence on multiplicity classes. It is observed that with increase in particle multiplicity, the non-extensivity parameter, $q$ decreases, which indicates the tendency of the produced system towards thermodynamic equilibration. The increase in strange particle multiplicity is observed to be due to the increase of temperature and not to the size of the freeze-out volume.
We present the energy spectra of the low lying doubly-charmed baryons using lattice quantum chromodynamics. We precisely predict the ground state mass of the charmed-strange Omega(cc) (1/2+) baryon to be 3712(11)(12) MeV which could well be the next doubly-charmed baryon to be discovered at the LHCb experiment at CERN. We also predict masses of other doubly-charmed strange baryons with quantum numbers 3/2+, 1/2-, and 3/2-.
The charge radii and quadrupole moments of baryons with nonzero strangeness are calculated using a parametrization method based on the symmetries of the strong interaction.
The transverse momentum (mass) spectra of the multi-strange and non-multi-strange (i.e. other identified) particles in central gold-gold (Au-Au), lead-lead (Pb-Pb), argon-muriate (Ar-KCl) and nickel-nickel (Ni-Ni) collisions over a wide energy range have been studied in this work. The experimental data measured by various collaborations have been analyzed. The blast-wave fit with Tsallis statistics is used to extract the kinetic freeze-out temperature and transverse flow velocity from the experimental data of transverse momentum (mass) spectra. The extracted parameters increase with the increase of collision energy and appear with the trend of saturation at the Beam Energy Scan (BES) energies at the Relativistic Heavy Ion Collider (RHIC). This saturation implies that the onset energy of phase transition of partial deconfinement is 7.7 GeV and that of whole deconfinement is 39 GeV. Furthermore, the energy scan/dependence of kinetic freeze-out scenarios are observed for the multi-strange and other identified particles, though the multiple freeze-out scenarios are also observed for various particles.
We report the multiplicity dependence of charged particle productions for $pi^{pm}$, $K^{pm}$, $p$, $overline{p}$ and $phi$ meson at $|y| < 1.0$ in p+p collisions at $sqrt{rm s}$ = 200 GeV with $rm PYTHIA$ simulation. The impact of parton multiple interactions and gluon contributions is studied and found to be possible sources of the particle yields splitting as a function of $p_T$ with respect to multiplicity. No obvious particle species dependence for the splitting is observed. The multiplicity dependence on ratios of $K^-/pi^-$, $K^+/pi^+$, $overline{p}/pi^-$, $p/pi^+$ and $Lambda/K^{0}_{s}$ in mid-rapidity in p+p collisions is found following the similar tendency as that in Au+Au collisions at $sqrt{s_{NN}}$ = 200 GeV from RHIC, which heralds the similar underlying initial production mechanisms despite the differences in the initial colliding systems.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
