From 468c0a74e1fd37450c16f92279fbaee7952d21ba Mon Sep 17 00:00:00 2001
From: Michael Pitt <m_u_pitt@yahoo.com>
Date: Wed, 16 Oct 2024 22:18:33 +0300
Subject: [PATCH] update dynamic range of B0 ECAL (#1623)

### Briefly, what does this PR introduce?
This RP solves the truncation in energy response of the B0 calorimeter
as reported in slide 11
[here](https://indico.bnl.gov/event/24923/#12-b0-emcal). The energy
threshold based on the simulated light yields of calorimeter crystals
interfaces with the readout (slide 12 from the presentation above)

### What kind of change does this PR introduce?
- [ ] Bug fix (issue #__)
- [ ] New feature (issue #__)
- [ ] Documentation update
- [X] Other: update thresholds in reconstruction

### Please check if this PR fulfills the following:
- [ ] Tests for the changes have been added
- [ ] Documentation has been added / updated
- [ ] Changes have been communicated to collaborators

### Does this PR introduce breaking changes? What changes might users
need to make to their code?
no
### Does this PR change default behavior?
restore correct energy response for B0 ECAL.

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
---
 src/detectors/B0ECAL/B0ECAL.cc | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/detectors/B0ECAL/B0ECAL.cc b/src/detectors/B0ECAL/B0ECAL.cc
index 9d912a822..10e8be761 100644
--- a/src/detectors/B0ECAL/B0ECAL.cc
+++ b/src/detectors/B0ECAL/B0ECAL.cc
@@ -33,11 +33,12 @@ extern "C" {
           {"B0ECalRawHits"},
 #endif
           {
-            .eRes = {0.0 * sqrt(dd4hep::GeV), 0.02, 0.0 * dd4hep::GeV},
+                         // The stocastic term is set using light yield in PbOW4 of N_photons = 145.75 / GeV / mm, for 6x6 mm2 sensors with PDE=0.18 (a=1/sqrt(145.75*36*0.18))
+            .eRes = {0.0326 * sqrt(dd4hep::GeV), 0.00, 0.0 * dd4hep::GeV},
             .tRes = 0.0 * dd4hep::ns,
             .threshold= 5.0 * dd4hep::MeV,
             .capADC = 16384,
-            .dyRangeADC = 20 * dd4hep::GeV,
+            .dyRangeADC = 170 * dd4hep::GeV,
             .pedMeanADC = 100,
             .pedSigmaADC = 1,
             .resolutionTDC = 1e-11,
@@ -50,12 +51,12 @@ extern "C" {
           "B0ECalRecHits", {"B0ECalRawHits"}, {"B0ECalRecHits"},
           {
             .capADC = 16384,
-            .dyRangeADC = 20. * dd4hep::GeV,
+            .dyRangeADC = 170. * dd4hep::GeV,
             .pedMeanADC = 100,
             .pedSigmaADC = 1,
             .resolutionTDC = 1e-11,
             .thresholdFactor = 0.0,
-            .thresholdValue = 0.0,
+            .thresholdValue = 1.0, // using threshold of 10 photons = 10 MeV = 1 ADC
             .sampFrac = "0.998",
             .readout = "B0ECalHits",
             .sectorField = "sector",