[PWGLF] Fix histogram filling (#11933)

Co-authored-by: Francesco Mazzaschi <fmazzasc@alipap1.cern.ch>

Author: fmazzasc

PWGLF/Tasks/Resonances/lambda1405analysis.cxx

@@ -178,7 +178,13 @@ struct lambda1405analysis {
     if (std::abs(sigmaCand.dcaMothPv()) > cutDCAtoPVSigma || std::abs(sigmaCand.dcaDaugPv()) < cutDCAtoPVPiFromSigma || sigmaRad < cutSigmaRadius) {
       return false;
     }
-    rLambda1405.fill(HIST("h2PtMassSigmaBeforeCuts"), sigmaCand.mothSign() * sigmaCand.ptMoth(), sigmaCand.mSigmaMinus());
+    if (lambda1405Cand.isSigmaMinus) {
+      rLambda1405.fill(HIST("h2PtMassSigmaBeforeCuts_0"), sigmaCand.mothSign() * sigmaCand.ptMoth(), sigmaCand.mSigmaMinus());
+    }
+    if (lambda1405Cand.isSigmaPlus) {
+      rLambda1405.fill(HIST("h2PtMassSigmaBeforeCuts_1"), sigmaCand.mothSign() * sigmaCand.ptMoth(), sigmaCand.mSigmaPlus());
+    }
+
     for (const auto& piTrack : tracks) {
       if (!doLSBkg) {
         if (piTrack.sign() == sigmaCand.mothSign()) {