We examined the transverse momentum(pT)spectra of various identified particles,encompassing both light-flavored and strange hadrons(π++π−,K++K−,p+p¯,ϕ,K0s,Λ+Λ¯,Ξ−+Ξ¯+,andΩ−+Ω¯+),across diff...We examined the transverse momentum(pT)spectra of various identified particles,encompassing both light-flavored and strange hadrons(π++π−,K++K−,p+p¯,ϕ,K0s,Λ+Λ¯,Ξ−+Ξ¯+,andΩ−+Ω¯+),across different multiplicity classes in proton-proton collisions(p-p)at a center-of-mass energy of s√=7 TeV.Utilizing the Tsallis and Hagedorn models,parameters relevant to the bulk properties of nuclear matter were extracted.Both models exhibit good agreement with experimental data.In our analyses,we observed a consistent decrease in the effective temperature(T)for the Tsallis model and the kinetic or thermal freeze-out temperature(T0)for the Hagedorn model,as we transitioned from higher multiplicity(class-I)to lower multiplicity(class-X).This trend is attributed to the diminished energy transfer in higher multiplicity classes.Additionally,we observed that the transverse flow velocity(βT)experiences a decline from class-I to class-X.The normalization constant,which represents the multiplicity of produced particles,was observed to decrease as we moved toward higher multiplicity classes.While the effective and kinetic freeze-out temperatures,as well as the transverse flow velocity,show a mild dependency on multiplicity for lighter particles,this dependency becomes more pronounced for heavier particles.The multiplicity parameter for heavier particles was observed to be smaller than that of lighter particles,indicating a greater abundance of lighter hadrons compared to heavier ones.Various particle species were observed to undergo decoupling from the fireball at distinct temperatures:lighter particles exhibit lower temperatures,while heavier ones show higher temperatures,thereby supporting the concept of multiple freeze-out scenarios.Moreover,we identified a positive correlation between the kinetic freeze-out temperature and transverse flow velocity,a scenario where particles experience stronger collective motion at a higher freeze-out temperature.The reason for this positive correlation is that,as the multiplicity increases,more energy is transferred into the system.This increased energy causes greater excitation and pressure within the system,leading to a quick expansion.展开更多
The transverse momentum distributions of charged hadrons produced in proton-proton collisions at center-of-mass energies(√s)of 0.9 TeV and 2.36 TeV,as measured by the CMS detector at the Large Hadron Collider(LHC),ha...The transverse momentum distributions of charged hadrons produced in proton-proton collisions at center-of-mass energies(√s)of 0.9 TeV and 2.36 TeV,as measured by the CMS detector at the Large Hadron Collider(LHC),have been analyzed within various pseudorapidity classes utilizing the thermodynamically consistent Tsallis distribution.The fitting procedure resulted in the key parameters,namely,effective temperature(T),non-extensivity parameter(q),and kinetic freezeout volume(V).Additionally,the mean transverse momentum(<pT>)and initial temperature(T_(i))of the particle source are determined through the fit function and string percolation method,respectively.An alternative method is employed to calculate the kinetic freezeout temperature(T_(0))and transverse flow velocity(β_(T))from T.Furthermore,thermodynamic quantities at the freezeout,including energy density(ε),particle density(n),entropy density(s),pressure(P),and squared speed of sound(C_(s)^(2)),are computed using the extracted T and q.It is also observed that,with a decrease in pseudorapidity,all thermodynamic quantities except V and q increase.This trend is attributed to greater energy transfer along the mid pseudorapidity.q increases towards higher values of pseudorapidity,indicating that particles close to the beam axis are far from equilibrium.Meanwhile,V remains nearly independent of pseudorapidity.The excitation function of these parameters(q)shows a direct(inverse)correlation with collision energy.The ε,n,s,and P show a strong dependence on collision energies at low pseudorapidities.Explicit verification of the thermodynamic inequality ε≥3P suggests the formation of a highly dense droplet-like Quark-Gluon Plasma(QGP).Additionally,the inequality T_(i)>T>T_(0)is explicitly confirmed,aligning with the evolution of the produced fireball.展开更多
基金Supported by Princess Nourah bint Abdulrahman University,Researchers Supporting Project Number PNURSP2024R106Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabia+3 种基金We would like to express our gratitude for the support received from Abdul Wali Khan University Mardan,PakistanHubei Uni versity of Automotive Technology,Doctoral Research Fund number BK202313University of GuyanaUniversity of Tabuk,Saudi Arabia and Qassim University,Saudi Arabia,whichhave contributed to creating a conducive research environment.
文摘We examined the transverse momentum(pT)spectra of various identified particles,encompassing both light-flavored and strange hadrons(π++π−,K++K−,p+p¯,ϕ,K0s,Λ+Λ¯,Ξ−+Ξ¯+,andΩ−+Ω¯+),across different multiplicity classes in proton-proton collisions(p-p)at a center-of-mass energy of s√=7 TeV.Utilizing the Tsallis and Hagedorn models,parameters relevant to the bulk properties of nuclear matter were extracted.Both models exhibit good agreement with experimental data.In our analyses,we observed a consistent decrease in the effective temperature(T)for the Tsallis model and the kinetic or thermal freeze-out temperature(T0)for the Hagedorn model,as we transitioned from higher multiplicity(class-I)to lower multiplicity(class-X).This trend is attributed to the diminished energy transfer in higher multiplicity classes.Additionally,we observed that the transverse flow velocity(βT)experiences a decline from class-I to class-X.The normalization constant,which represents the multiplicity of produced particles,was observed to decrease as we moved toward higher multiplicity classes.While the effective and kinetic freeze-out temperatures,as well as the transverse flow velocity,show a mild dependency on multiplicity for lighter particles,this dependency becomes more pronounced for heavier particles.The multiplicity parameter for heavier particles was observed to be smaller than that of lighter particles,indicating a greater abundance of lighter hadrons compared to heavier ones.Various particle species were observed to undergo decoupling from the fireball at distinct temperatures:lighter particles exhibit lower temperatures,while heavier ones show higher temperatures,thereby supporting the concept of multiple freeze-out scenarios.Moreover,we identified a positive correlation between the kinetic freeze-out temperature and transverse flow velocity,a scenario where particles experience stronger collective motion at a higher freeze-out temperature.The reason for this positive correlation is that,as the multiplicity increases,more energy is transferred into the system.This increased energy causes greater excitation and pressure within the system,leading to a quick expansion.
基金Supported by Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2024R106), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabiathe authors extend their appreciation to the Deanship of Scientific Research at Northern Border University, Arar, KSA for funding this research work through the project number “NBU-FFR-2024-2461-04”University,Riyadh,Saudi Arabia.In addition,the authors extend their appreciation to the Deanship of Scientific Research at Northern Border University,Arar,KSA for funding this research work through the project number“NBU-FFR-2024-2461-04”。
文摘The transverse momentum distributions of charged hadrons produced in proton-proton collisions at center-of-mass energies(√s)of 0.9 TeV and 2.36 TeV,as measured by the CMS detector at the Large Hadron Collider(LHC),have been analyzed within various pseudorapidity classes utilizing the thermodynamically consistent Tsallis distribution.The fitting procedure resulted in the key parameters,namely,effective temperature(T),non-extensivity parameter(q),and kinetic freezeout volume(V).Additionally,the mean transverse momentum(<pT>)and initial temperature(T_(i))of the particle source are determined through the fit function and string percolation method,respectively.An alternative method is employed to calculate the kinetic freezeout temperature(T_(0))and transverse flow velocity(β_(T))from T.Furthermore,thermodynamic quantities at the freezeout,including energy density(ε),particle density(n),entropy density(s),pressure(P),and squared speed of sound(C_(s)^(2)),are computed using the extracted T and q.It is also observed that,with a decrease in pseudorapidity,all thermodynamic quantities except V and q increase.This trend is attributed to greater energy transfer along the mid pseudorapidity.q increases towards higher values of pseudorapidity,indicating that particles close to the beam axis are far from equilibrium.Meanwhile,V remains nearly independent of pseudorapidity.The excitation function of these parameters(q)shows a direct(inverse)correlation with collision energy.The ε,n,s,and P show a strong dependence on collision energies at low pseudorapidities.Explicit verification of the thermodynamic inequality ε≥3P suggests the formation of a highly dense droplet-like Quark-Gluon Plasma(QGP).Additionally,the inequality T_(i)>T>T_(0)is explicitly confirmed,aligning with the evolution of the produced fireball.
