Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userParticle yields in pp interactions at $sqrt{s}=17.3$ GeV interpreted in the statistical hadronization model
79
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The unified set of yields of particles produced in proton-proton collisions at $sqrt{s}$ = 17.3 GeV (laboratory beam momentum 158 GeV/c) is evaluated, combining the experimental results of the NA49 and NA61/SHINE collaborations at the CERN SPS. With the statistical hadronization code Thermal-Fist we confirm the unacceptably high value of $chi^2$, both in the canonical and grand canonical - strangeness canonical approach, and the common volume for all the hadrons. The use of the energy-dependent width of the Breit-Wigner parametrization for the mass distributions of unstable particles improves the quality of the description of particle yields only slightly. We confirm the observation that exclusion of the $phi$ meson yield makes the fit result acceptable. The complete experimental data set of particle yields can be reasonably fitted if the canonical volumes of hadrons without and with open strangeness are allowed to vary independently. The canonical volume of strangeness was found larger than that for non-strange hadrons, which is compatible with the femtoscopy measurements of p+p system at $sqrt{s} = $ 27.4 MeV and 900 MeV. The model with the best-fit parameters allows to predict the yields of several not yet measured particles emitted from p+p at $sqrt{s}$ = 17.3 GeV.
rate research
Read More
A thermal-model analysis of particle production of p-p collisions at sqrt(s) = 17 GeV using the latest available data is presented. The sensitivity of model parameters on data selections and model assumptions is studied. The system-size dependence of thermal parameters and recent differences in the statistical model analysis of p-p collisions at the super proton synchrotron (SPS) are discussed. It is shown that the temperature and strangeness undersaturation factor depend strongly on kaon yields which at present are still not well known experimentally. It is conclude, that within the presently available data at the SPS it is rather unlikely that the temperature in p-p collisions exceeds significantly that expected in central collisions of heavy ions at the same energy.
An analysis is made of the particle composition in the final state of $pp$ collisions at 7 TeV as a function of the charged particle multiplicity ($dN_{ch}/deta$). The thermal model is used to determine the chemical freeze-out temperature as well as the radius and strangeness suppression factor $gamma_s$. Three different ensembles are used in the analysis. The grand canonical ensemble, the canonical ensemble with exact strangeness conservation and the canonical ensemble with exact baryon number, strangeness and electric charge conservation. It is shown that for the highest multiplicity class the three ensembles lead to the same result. This allows us to conclude that this multiplicity class is close to the thermodynamic limit. It is estimated that the final state in $pp$ collisions could reach the thermodynamic limit when $dN_{ch}/deta$ is larger than twenty per unit of rapidity, corresponding to about 300 particles in the final state when integrated over the full rapidity interval.
We present the first inclusive measurements of the invariant and SoftDrop jet mass in proton-proton collisions at $sqrt{s}=200$ GeV at STAR. The measurements are fully corrected for detector effects, and reported differentially in both the jet transverse momentum and jet radius parameter. We compare the measurements to established leading-order Monte Carlo event generators and find that STAR-tuned PYTHIA-6 reproduces the data, while LHC tunes of PYTHIA-8 and HERWIG-7 do not agree with the data, providing further constraints on parameter tuning. Finally, we observe that SoftDrop grooming, for which the contribution of wide-angle non-perturbative radiation is suppressed, shifts the jet mass distributions into closer agreement with the partonic jet mass as determined by both PYTHIA-8 and a next-to-leading-logarithmic accuracy perturbative QCD calculation. These measurements complement recent LHC measurements in a different kinematic region, as well as establish a baseline for future jet mass measurements in heavy-ion collisions at RHIC.
Pentaquark states have been extensively investigated theoretically in the context of the constituent quark model. In this paper results of an experimental search for pentaquarks in the Ximpim, Ximpip, Xippim and Xippip invariant mass spectra in proton-proton interactions at $sqrt{s}$=17.3~GeV are presented. Previous possible evidence from the NA49 collaboration of the existence of a narrow Ximpim baryon resonance in p+p interactions is not confirmed with almost 10 times greater event statistics. The search was performed using the NASixtyOne detector which reuses the main components of the NA49 apparatus. No signal was observed with either the selection cuts of NA49 or newly optimised cuts.
In relativistic nuclear collisions the production of hadrons with light (u,d,s) quarks is quantitatively described in the framework of the Statistical Hadronization Model (SHM). Charm quarks are dominantly produced in initial hard collisions but interact strongly in the hot fireball and thermalize. Therefore charmed hadrons can be incorporated into the SHM by treating charm quarks as impurities with thermal distributions, while the total charm content of the fireball is fixed by the measured open charm cross section. We call this model SHMc and demonstrate that with SHMc the measured multiplicities of single charm hadrons in lead-lead collisions at LHC energies can be well described with the same thermal parameters as for (u,d,s) hadrons. Furthermore, transverse momentum distributions are computed in a blast-wave model, which includes the resonance decay kinematics. SHMc is extended to lighter collision systems down to oxygen-oxygen and includes doubly- and triply-charmed hadrons. We show predictions for production probabilities of such states exhibiting a characteristic and quite spectacular enhancement hierarchy.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
