Class eos_had_potential (o2scl)

O2scl : Class List

class eos_had_potential : public o2scl::eos_had_eden_base

Generalized potential model equation of state.

The single particle energy is defined by the functional derivative of the energy density with respect to the distribution function

\[ e_{\tau} = \frac{\delta \varepsilon}{\delta f_{\tau}} \]

The effective mass is defined by

\[ \frac{m^{*}}{m} = \left( \frac{m}{k} \frac{d e_{\tau}}{d k} \right)^{-1}_{k=k_F} \]

In all of the models, the kinetic energy density is \(\tau_n+\tau_p\) where

\[ \tau_i = \frac{2}{(2 \pi)^3} \int d^3 k~ \left(\frac{k^2}{2 m}\right)f_i(k,T) \]
and the number density is
\[ \rho_i = \frac{2}{(2 \pi)^3} \int d^3 k~f_i(k,T) \]

See the review in [Li01].

When form is equal to mdi_form or gbd_form, the potential energy density is given by

\[ V(\rho,\delta) = \frac{Au}{\rho_0} \rho_n \rho_p + \frac{A_l}{2 \rho_0} \left(\rho_n^2+\rho_p^2\right)+ \frac{B}{\sigma+1} \frac{\rho^{\sigma+1}}{\rho_0^{\sigma}} \left(1-x \delta^2\right)+V_{mom}(\rho,\delta) \]
where \(\delta=1-2 \rho_p/(\rho_n+\rho_p)\).

This potential energy is from [Das03].

If form is equal to mdi_form, then

\[ V_{mom}(\rho,\delta)= \frac{1}{\rho_0} \sum_{\tau,\tau^{\prime}} C_{\tau,\tau^{\prime}} \int \int d^3 k d^3 k^{\prime} \frac{f_{\tau}(\vec{k}) f_{{\tau}^{\prime}} (\vec{k}^{\prime})} {1-(\vec{k}-\vec{k}^{\prime})^2/\Lambda^2} \]
where \(C_{1/2,1/2}=C_{-1/2,-1/2}=C_{\ell}\) and \(C_{1/2,-1/2}=C_{-1/2,1/2}=C_{u}\). Later

parameterizations in this form are given in [Chen05].

Otherwise if form is equal to gbd_form, then

\[ V_{mom}(\rho,\delta)= \frac{1}{\rho_0}\left[ C_{\ell} \left( \rho_n g_n + \rho_p g_p \right)+ C_u \left( \rho_n g_p + \rho_p g_n \right) \right] \]
where
\[ g_i=\frac{\Lambda^2}{\pi^2}\left[ k_{F,i}-\Lambda \mathrm{tan}^{-1} \left(k_{F,i}/\Lambda\right) \right] \]

Otherwise, if form is equal to bgbd_form, bpal_form or sl_form, then the potential energy density is given by:

\[ V(\rho,\delta) = V_A+V_B+V_C \]
\[ V_A = \frac{2 A}{3 \rho_0} \left[ \left(1+\frac{x_0}{2}\right)\rho^2- \left(\frac{1}{2}+x_0\right)\left(\rho_n^2+\rho_p^2\right)\right] \]
\[ V_B=\frac{4 B}{3 \rho_0^{\sigma}} \frac{T}{1+4 B^{\prime} T / \left(3 \rho_0^{\sigma-1} \rho^2\right)} \]
where
\[ T = \rho^{\sigma-1} \left[ \left( 1+\frac{x_3}{2} \right) \rho^2 - \left(\frac{1}{2}+x_3\right)\left(\rho_n^2+\rho_p^2\right)\right] \]
The term \(V_C\) is:
\[ V_C=\sum_{i=1}^{i_{\mathrm{max}}} \frac{4}{5} \left(C_{i}+2 z_i\right) \rho (g_{n,i}+g_{p,i})+\frac{2}{5}\left(C_i -8 z_i\right) (\rho_n g_{n,i} + \rho_p g_{p,i}) \]
where
\[ g_{\tau,i} = \frac{2}{(2 \pi)^3} \int d^3 k f_{\tau}(k,T) g_i(k) \]

This potential energy is from [Bombaci01].

For form is equal to bgbd_form or form is equal to bpal_form, the form factor is given by

\[ g_i(k) = \left(1+\frac{k^2}{\Lambda_i^2}\right)^{-1} \]
while for form is equal to sl_form, the form factor is given by
\[ g_i(k) = 1-\frac{k^2}{\Lambda_i^2} \]
where \(\Lambda_1\) is specified in the parameter Lambda when necessary.

Bug:

The BGBD and SL EOSs do not work.

Idea for Future:

Calculate the chemical potentials analytically.

Subclassed by o2scl::eos_had_sym4_mdi

The parameters for the various interactions

double x
double Au
double Al
double rho0
double B
double sigma
double Cl
double Cu
double Lambda
double A
double x0
double x3
double Bp
double C1
double z1
double Lambda2
double C2
double z2
double bpal_esym
int sym_index
int form

Form of potential.

deriv_gsl def_mu_deriv

The default derivative object for calculating chemical potentials.

static const int mdi_form = 1

The “momentum-dependent-interaction” form from Das et al. (2003)

See [Das03].

static const int bgbd_form = 2

The modifed GBD form.

static const int bpal_form = 3

The form from Prakash et al. (1988) as formulated in Bombaci et al. (2001)

See [Prakash88] and [Bombaci01].

static const int sl_form = 4

The “SL” form. See Bombaci et al. (2001)

See [Bombaci01].

static const int gbd_form = 5

The Gale, Bertsch, Das Gupta from Gale et al. 1987.

See [Gale87].

static const int pal_form = 6

The form from Prakash et al. 1988.

See [Prakash88].

fermion_nonrel nrf

Non-relativistic fermion thermodyanmics.

bool mu_deriv_set

True of the derivative object has been set.

deriv_base *mu_deriv_ptr

The derivative object.

eos_had_potential()
inline virtual int calc_temp_f_gen(double nB, double nQ, double nS, double T, thermo &th)

Equation of state as a function of baryon, charge, and strangeness density at finite temperature.

virtual int calc_e(fermion &ne, fermion &pr, thermo &lt)

Equation of state as a function of density.

inline int set_mu_deriv(deriv_base<> &de)

Set the derivative object to calculate the chemical potentials.

inline virtual const char *type()

Return string denoting type (“eos_had_potential”)

double mom_integral(double pft, double pftp)

Compute the momentum integral for mdi_form.

The mode for the energy() function [protected]

int mode
static const int nmode = 1
static const int pmode = 2
static const int normal = 0
double energy(double x)

Compute the energy.