Energy reconstruction of hadrons in highly granular combined ECAL and HCAL systems
This paper discusses the hadronic energy reconstruction of two combined electromagnetic and hadronic calorimeter systems using physics prototypes of the CALICE collaboration: the silicon-tungsten electromagnetic calorimeter (Si-W ECAL) and the scintillator-SiPM based analog hadron calorimeter (AHCAL); and the scintillator-tungsten electromagnetic calorimeter (ScECAL) and the AHCAL. These systems were operated in hadron beams at CERN and FNAL, permitting the study of the performance in combined ECAL and HCAL systems. Two techniques for the energy reconstruction are used, a standard reconstruction based on calibrated sub-detector energy sums, and one based on a software compensation algorithm making use of the local energy density information provided by the high granularity of the detectors. The software compensation-based algorithm improves the hadronic energy resolution by up to 30% compared to the standard reconstruction. The combined system data show comparable energy resolutions to the one achieved for data with showers starting only in the AHCAL and therefore demonstrate the success of the inter-calibration of the different sub-systems, despite of their different geometries and different readout technologies.
Energy Reconstruction of Hadrons in a Highly Granular SiW ECAL and Plastic Scintillator HCAL Calorimeter System
The hadronic energy resolution for the combined CALICE Si-W ECAL, AHCAL and TCMT setup is studied in the energy range of 4 GeV to 80 GeV using data recorded at CERN and at FNAL with and without software compensation. Up to 30% improvement of energy resolution is achieved with software compensation, resulting in a stochastic term of 42.55%/ √ E/GeV and a constant term of 2.5%. This performance is comparable to previous studies for hadron showers starting in the AHCAL. ∗Corresponding authors: Yasmine Israeli (israeli@mpp.mpg.de), Frank Simon (fsimon@mpp.mpg.de)
Palaeomicrobiology: current issues and perspectives
Palaeomicrobiology is an emerging field that is devoted to the detection, identification and characterization of microorganisms in ancient remains. Data indicate that host-associated microbial DNA can survive for almost 20,000 years, and environmental bacterial DNA preserved in permafrost samples has been dated to 400,000–600,000 years. In addition to frozen and mummified soft tissues, bone and dental pulp can also be used to search for microbial pathogens. Various techniques, including microscopy and immunodetection, can be used in palaeomicrobiology, but most data have been obtained using PCR-based molecular techniques. Infections caused by bacteria, viruses and parasites have all been diagnosed using palaeomicrobiological techniques. Additionally, molecular typing of ancient pathogens could help to reconstruct the epidemiology of past epidemics and could feed into current models of emerging infections, therefore contributing to the development of appropriate preventative measures.