Excitation Function of Kinetic Freeze-Out Parameters at 6.3, 17.3, 31, 900 and 7000 GeV

oleh: Muhammad Waqas, Abd Al Karim Haj Ismail, Muhammad Ajaz, Atef AbdelKader

Format: Article
Diterbitkan: MDPI AG 2022-02-01

Deskripsi

The transverse momentum spectra of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>π</mi><mo>+</mo></msup></semantics></math></inline-formula> (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mi>π</mi><mo>−</mo></msup></semantics></math></inline-formula>)(<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msup><mi>π</mi><mo>+</mo></msup><mo>+</mo><msup><mi>π</mi><mo>−</mo></msup></mrow></semantics></math></inline-formula>) at 6.3, 17.3, 31, 900 and 7000 GeV are analyzed by the blast-wave model with Tsallis statistics (TBW) in proton-proton collisions. We took the value of flow profile <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>n</mi><mn>0</mn></msub></semantics></math></inline-formula> = 1 and 2 in order to see the difference in the results of the extracted parameters in the two cases. Different rapidity slices at 31 GeV are also analyzed, and the values of the related parameters, such as kinetic freeze-out temperature, transverse flow velocity and kinetic freeze-out volume, are obtained. The above parameters rise with the increase of collision energy, while at 31 GeV, they decrease with increasing rapidity, except for the kinetic freeze-out volume, which increases. We also extracted the parameter <i>q</i>, which is an entropy-based parameter, and its rising trend is noticed with increasing collision energy, while at 31 GeV, no specific dependence of <i>q</i> is observed on rapidity. In addition, the multiplicity parameter <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>N</mi><mn>0</mn></msub></semantics></math></inline-formula> and mean transverse momentum are extracted, which increase with increasing collision energy and decrease with increasing rapidity. We notice that the kinetic freeze-out temperature and mean transverse momentum are slightly larger with <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>n</mi><mn>0</mn></msub></semantics></math></inline-formula> = 2, while the transverse flow velocity is larger in the case of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>n</mi><mn>0</mn></msub></semantics></math></inline-formula> = 1, but the difference is very small and hence insignificant.