Abstract
We review recent discussions regarding the parity-odd contribution to the trace anomaly of a chiral fermion. We pay special attention to the perturbative approach in terms of Feynman ...diagrams, comparing in detail the results obtained using dimensional regularization and the Breitenlohner–Maison prescription with other approaches.
Motivated by the strong constraints to noncommutative quantum theories coming from Gamma Ray Bursts and the precision attained by SQUID devices in measuring magnetic fields, we study in this article ...the thermodynamic behaviour of a Fermi gas subject to the action of a background magnetic field, in two and three dimensional space with noncommutative coordinates and momenta. An explicit expression is obtained for the magnetization and magnetic susceptibility of the gas, both for Landau’s diamagnetism and Pauli’s paramagnetism. We are lead in this way to an upper bound
θ
≲
(
10
Gev
)
-
2
for the noncommutative parameter.
Tests of a dual-readout fiber calorimeter with SiPM light sensors Antonello, M.; Caccia, M.; Cascella, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2018, Letnik:
899, Številka:
C
Journal Article
Recenzirano
Odprti dostop
In this paper, we describe the first tests of a dual-readout fiber calorimeter in which silicon photomultipliers are used to sense the (scintillation and Čerenkov) light signals. The main challenge ...in this detector is implementing a design that minimizes the optical crosstalk between the two types of fibers, which are located very close to each other and carry light signals that differ in intensity by about a factor of 60. The experimental data, which were obtained with beams of high-energy electrons and muons as well as in lab tests, illustrate to what extent this challenge was met. The Čerenkov light yield, a limiting factor for the energy resolution of this type of calorimeter, was measured to be about twice that of the previously tested configurations based on photomultiplier tubes. The lateral profiles of electromagnetic showers were measured on a scale of millimeters from the shower axis and significant differences were found between the profiles measured with the scintillating and the Čerenkov fibers.
Future circular electron–positron colliders operating at s=90, 160, 240 and 350 GeV as Z, W, H and t factories will demand experiments with superior momentum and energy resolution for all the ...possible final-state particles produced. The IDEA Detector aims at satisfying these requests by exploiting an ultra-light drift chamber as the largest central tracker and a dual-readout fiber calorimeter for both electromagnetic and hadronic energy measurements. In this paper I review the dual-readout calorimeter baseline choices, as well as the related R&D work.
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