From 3fef8b22a8c62c66b6149e0d5d207d4e0ac77a61 Mon Sep 17 00:00:00 2001
From: David Nathan Brown <dave_brown@lbl.gov>
Date: Tue, 17 Sep 2024 17:42:30 -0700
Subject: [PATCH] Fix sign bug

---
 Trajectory/LoopHelix.hh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Trajectory/LoopHelix.hh b/Trajectory/LoopHelix.hh
index 3ca68451..19319bce 100644
--- a/Trajectory/LoopHelix.hh
+++ b/Trajectory/LoopHelix.hh
@@ -79,7 +79,7 @@ namespace KinKal {
       double momentumVariance(double time=0) const;
       double positionVariance(double time,MomBasis::Direction dir) const;
       PMAT planeCovariance(double time,Plane const& plane) const;
-      double energy(double time=0) const  { return  ebar()*Q(); }
+      double energy(double time=0) const  { return  fabs(ebar()*Q()); }
       VEC3 direction(double time, MomBasis::Direction mdir= MomBasis::momdir_) const;
       double mass() const { return mass_;} // mass
       int charge() const { return charge_;} // charge in proton charge units