Estimation of $e^-$, $\pi^-$ and $e^+$ cross sections for E99-117

Estimation of $e^-$, $\pi^-$ and $e^+$ cross sections for E99-117 is listed below. We expect Wiser and Whitlow's fit are good in E99-117 kinematic region for $\pi^-$ and $e^+$, respectively. Then estimation of $\pi^-$ and $e^+$ background are presented based on these two codes.

$p_e$(GeV/c)	1.450	1.200	0.890
$\pi^-$(epc)(nb/GeV-sr)	0.259	0.304	0.390
$\pi^-$(wiser)(nb/GeV-sr)	4.520	29.452	223.922
$e^-$(qfs)(nb/GeV-sr)	1.700	2.949	5.084
$e^-$(whitlow)(nb/GeV-sr)	0.875	1.830	3.485
$e^-$(rosetail)	0.012	0.040	0.198
$e^+$(epc)(nb/GeV-sr)	0.00465	0.00568	0.00858
$e^+$(wiser) (nb/GeV-sr)	0.01578	0.11424	1.11099
$\pi^-/e^-$(epc/[qfs+rosetail])	0.151	0.102	0.07386
$\pi^-/e^-$(wiser/[qfs+rosetail])	2.639	9.853	42.391
$\pi^-/e^-$(epc/[whitlow+rosetail])	0.292	0.162	0.106
$\pi^-/e^-$(wiser/[whitlow+rosetail])	5.096	15.748	60.796
$\pi^-/e^-$(estimation)	$\sim$10	$\sim$20	$\sim$100
$e^+/e^-$(epc/[qfs+rosetail])	0.00269	0.00189	0.00161
$e^+/e^-$(wiser/[qfs+rosetail])	0.00921	0.03822	0.21032
$e^+/e^-$(epc/[whitlow+rosetail])	0.00519	0.00301	0.00231
$e^+/e^-$(wiser/[whitlow+rosetail])	0.01779	0.06108	0.30164
$e^+/e^-$(estimation)	$\sim$ 0.7%	$\sim$ 2%	$\sim$ 5%

From the above table we can conclude that $\pi$ background is not high and it is sufficient to use Cerenkov and shower-preshower counter to extract it. For positron background we need some positron runs.