The non-extensivity parameter of a thermodynamical model of hadronic interactions at LHC energies

Tadeusz Wibig (1)

1 The Andrzej Sołtan Institute for Nuclear Studies

The LHC measurements above SPS and Tevatron energies give an opportunity to test predictions of the non-extensive thermodynamical picture of hadronic interaction to examine the measured transverse momentum distributions for new a interaction energy range. We determined the Tsallis model non-extensivity parameter for the hadronization process before short-lived particles decay and distort the initial p ⊥ distribution. We have shown that it follows exactly the smooth rise determined at lower energies below the present LHC record. The energy dependence of the q parameter is consistent with expectations and the evidence of the asymptotic limit may be seen. The thermodynamical concept of the hadronization process following the fifty-year old Hagedorn idea was recently successfully used in [ 1 ] to describe multiplicities in p¯ p, e + e −, and N N high energy interactions. However , the main problem of such a treatment: the nonexponential tails of transverse momentum distributions remains. One explanation is proposed in [ 2 ] introducing the pre-hadronization dynamics of fireballs. A different, more general, solution is to extend the standard, Boltzmann statistics following the Tsallis idea [ 3 ]. The generalised , non-extensive statistics technique is often used to describe different kinds of phenomena: from interstellar dynamics to the cosmic ray source puzzle [ 4 ]. Among them high energy interaction phenomenology is one of the fields where the new statistics is very successful. It was shown that such non-extensive statistics works well for p ⊥ spectra in e + e − [ 5 ], and could be used for p¯ p and pp interactions too [ 6, 7 ]. Here we show that the results of the Tsallis generalisation of the Becattini canonical thermodynamics works well when applied also to the LHC energies: 2.36 and 7 TeV. In Refs. [ 9 ] and [ 10 ] the function of the form inspired by the Tsallis formula

Mots clés: 12.40.Ee; 13.85.Hd; 13.85.Rm; 89.75.-k

Tadeusz Wibig. The non-extensivity parameter of a thermodynamical model of hadronic interactions at LHC energies. Journal of Physics G: Nuclear and Particle Physics, 2010, 37 (11), pp.115009. ⟨10.1088/0954-3899/37/11/115009⟩. ⟨hal-00600778⟩