Hi,
I've asked this question while ago but I haven't heard anything.
I raised two issues but only one is real.
E*theta^2 distribution appears to be out of kinematic limit but that's
effect of beam angle spread from non-zero transverse size of beam
decay pipe.
The other issue was electron rest mass, which I don't think it can not
make real effect itself on observable in the experiment.
But the odd behavior of software might be a hint of bug (big or small)
in the code.
thanks,
Jaewon
On Mon, Aug 19, 2013 at 11:06 AM, Jaewon Park <[log in to unmask]> wrote:
> Hi,
>
> I found an odd behavior of electron invariant mass from nu-e scattering.
> If I calculate electron rest mass using 4-momentum, i.e. m=sqrt(E^2-p^2), it
> shows odd tail besides an electron mass spike (h_e_mass_NUE.png)
> This plot contains both initial electron and recoil electron.
> If I plot them separately, it's more clearer.
> Initial electron mass is OK (h_e_mass_NUE_initial.png) but recoil electron
> mass is bad (h_e_mass_NUE_final.png)
>
> As a check, I did same thing for muon from inverse muon decay, I got right
> muon mass (h_muon_mass_IMD.png)
> In another check, rest mass from nu_e CC electron was also correct
> (h_e_mass_allevt.png).
>
> There is another odd behavior that might be related with the invariant mass
> problem.
> From pure two body kinematics, it should obey E*theta^2 < 2*(electron mass)
> but tail sneaks out (h_true_Eth2.png)
>
> thanks,
>
> Jaewon
>
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