Simple parameterization of nuclear attenuation data

Abstract

Based on the nuclear attenuation data obtained by the HERMES experiment on nitrogen and krypton nuclei, it is shown that the nuclear attenuation R h M can be parametrised in a form of a linear polynomial P1 = a11 + τ a12, where τ is the formation time, which depends on the energy of the virtual photon ν and fraction of that energy z carried by the final hadron. Three widely known parameterizations for τ were used for the performed fit. The fit parameters a11 and a12 do not depend on ν and z.

Multidimensional study of hadronization in nuclei

“…The wealth of theoretical model calculations and studies [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] reflect the strong interest of the community in hadron-multiplicities on nuclei, as they provide information on the space (time) structure of the hadronization process. It is beyond the scope of this paper to compare the results of the various models with the data.…”

Study of the hadronization process in cold nuclear medium

“…where n exp and n par are numbers of experimental points and parameters; R h M (theor) is the theoretical value for ratio at given point; (15). In version with τ c (4) ( Table 2) for each choice of σ str we have approximately equal values ofχ 2 for NDFs from (15) and (16).…”

“…2 Fit of version with τ c (4) can depend from the standard Lund model parameter C. The widely using value of this parameter is C = 0.3 [32]. For study the dependence of fit from this parameter we performed three parametric fit with τ c (4), σ str (10), NDF from (15). As parameters serve σ q , parameter c, and Lund parameter C, which in our fit can changes in limits 0.2 ≤ C ≤ 0.5.…”

“…In the above formula more variables like the photon virtuality-Q 2 , transverse hadron momentum in respect to the virtual photon direction-p t , over which the NA is averaged, are not written. At present, several phenomenological models for description of the NA [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] are available. The simple version of the string model, so called TwoScale Model (TSM), was proposed by European Muon Collaboration for the description of its experimental data [2].…”

Nuclear attenuation - 2 dimensional dependences at HERMES

“…[7][8][9][10][11][12] and references therein. It is beyond the scope of this report to compare the results of the various models with the data.…”