From cf6a95b74592282ee6e8278020a1982ce476baf3 Mon Sep 17 00:00:00 2001
From: hristov <hristov@f7af4fe6-9843-0410-8265-dc069ae4e863>
Date: Mon, 22 Mar 2004 07:27:17 +0000
Subject: [PATCH] Density effect added (Yu.Belikov)

---
 TPC/AliTPCpidESD.cxx | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/TPC/AliTPCpidESD.cxx b/TPC/AliTPCpidESD.cxx
index 32a21190560..29f447e44dc 100644
--- a/TPC/AliTPCpidESD.cxx
+++ b/TPC/AliTPCpidESD.cxx
@@ -41,7 +41,11 @@ Double_t AliTPCpidESD::Bethe(Double_t bg) {
   // This is the Bethe-Bloch function normalised to 1 at the minimum
   //
   Double_t bg2=bg*bg;
-  Double_t bethe=(1.+ bg2)/bg2*(log(5940*bg2) - bg2/(1.+ bg2));
+  Double_t bethe;
+  if (bg<3.5e1) 
+      bethe=(1.+ bg2)/bg2*(log(5940*bg2) - bg2/(1.+ bg2));
+  else // Density effect ( approximately :) 
+      bethe=1.15*(1.+ bg2)/bg2*(log(3.5*5940*bg) - bg2/(1.+ bg2));
   return bethe/11.091;
 }
 
-- 
2.31.1