Trying to get symbols to display a formula in title of uiaxes bar plot

I am trying to get symbols to display a formula in title of uiaxes bar plot. In the beginning it was like this. I enter this code :

app.UIAxes_4.Title.String = 'Sigma of each cell, $$\sigma = \sqrt{1/N*\Sigma_N(E-R_{ref})^2}$$'

and then I got this.

This is correct. But I want to add this along with it

This is from another normal plot and i generated this by using the code :

titl1 ='best \sigma = ';
titl2 = num2str(app.bestSigma);
titl3 = ' worst \sigma= ';
titl4 = num2str(app.worstSigma);
titl = strcat(titl1,titl2,titl3,titl4);
app.UIAxes_3.Title.String = titl;

And now I try to combine this :

titl1 ='Sigma of each cell, $$\sigma = \sqrt{1/N*\Sigma_N(E-R_{ref})^2}$$, best \sigma = ';
titl2 = num2str(app.bestSigma);
titl3 = ' worst \sigma= ';
titl4 = num2str(app.worstSigma);
titl = strcat(titl1,titl2,titl3,titl4);
app.UIAxes_4.Title.String = titl;

But I end up getting this :

I even tried this :

app.UIAxes_4.Title.String = "Sigma of each cell, $$\sigma = \sqrt{1/N*\Sigma_N(E-R_{ref})^2}$$, best \sigma = " + num2str(app.bestSigma) + " worst \sigma= " + num2str(app.worstSigma);

and still ended up getting the same wrong answer.

So how can I combine the first two images to get the solutioin for a title in an UIaxes bar plot. Thank you.

[Epsilon]

Try:

titl = sprintf(['Sigma of each cell, $$\\sigma = \\sqrt{\\frac{1}{N}\\sum_N(E-R_{ref})^2}$$, ', ...
                'best $\\sigma = %.3f$, worst $\\sigma = %.3f$'], ...
                app.bestSigma, app.worstSigma);
app.UIAxes_4.Title.String = titl;
app.UIAxes_4.Title.Interpreter = 'latex';

Answer 1

[Govind Sankar Madhavan Pillai Ramachandran Nair]

Thank you very much. It worked, but there is a new issue. This issue was there before as well, that as you can see in the title sigma of each cell and the formula are in two different lines. I ignored it at that, but when we add the new stuff to it, the whole title is in 3 lines which makes the plot too small and totally doesnt look good.

I tried changing the title from char array to a string, but didnt help, it went to the old issue, of not showing the formula. Is it possible to put it in one line or its either 3 lines or nothing.