How to force Mathematica to plot the function near zero?

Question

I have the code of the function

InversedsToGeV = 1/(1.5*10^24);
GammatotalBInInverseds = (1.638*10^-12)^-1;
GammatotalB = GammatotalBInInverseds*InversedsToGeV
mB = 5.279;
mK = 0.493;
mPi = 0.14;
vhiggs = 240;
ebs = 3.6*10^-4;
ebd = 7.9*10^-5;
fBK = 0.33;
fBpi = 0.258;
MBpole = Sqrt[38];
msquark = 0.09;
mbquark = 4.65;
BKFormFactor[S_] = fBK/(1 - S/MBpole^2);
BpiFormFactor[S_] = fBpi/(1 - S/MBpole^2);
BrscalarBtoK[MS_] = 
  Piecewise[{{1/(8*Pi) 1/(
      mB GammatotalB) (mbquark/vhiggs*BKFormFactor[MS^2]*
        ebs*(mB^2 - mK^2)/(mbquark - msquark))^2 (1 + MS^4/mB^4 + 
        mK^4/mB^4 - 2*MS^2*mK^2/mB^4 - 2*mK^2/mB^2 - 2*MS^2/mB^2)^(
      1/2)/2, MS < mB - mK}, {0, True}}];

I try to plot the function BrscalarBtoK with the code

LogPlot[{BrscalarBtoK[m\[Phi]]}, {m\[Phi], 0.21, 10}, 
 FrameLabel -> {"\!\(\*SubscriptBox[\(m\), \(\[Phi]\)]\) [GeV]", 
   "\!\(\*SubscriptBox[\(P\), \(meson\)]\)/\!\(\*SuperscriptBox[\(\
\[Theta]\), \(2\)]\)"}, Frame -> True, 
 FrameStyle -> Directive[Black, 35], 
 PlotRange -> {{0, 10}, {10^-5, 5}}, 
 PlotStyle -> {{Thick, Blue, Thickness[0.005]}}, 
 GridLines -> Automatic, ImageSize -> Large]

The result is on the left picture below. However, I want it to be like on the right picture below and don't understand what is the reason for this incorrect plotting. Can you please help me with this problem?

Answer 1

Add a second plot that is focused on the region you want, with increased PlotPoints to help the sampling:

plot2 = LogPlot[{BrscalarBtoK[m\[Phi]]}, {m\[Phi], mB - mK - 10^-2, 
   mB - mK}, PlotRange -> All, PlotPoints -> 2000, ImageSize -> Large,
   PlotStyle -> Red]

Show[plot1,plot2]