MALTA is part of the Depleted Monolithic Active Pixel sensors designed in Tower 180 nm CMOS imaging technology. A custom telescope with six MALTA planes has been developed for test beam campaigns at SPS, CERN, with the ability to host several devices under test. The telescope system has a dedicated custom readout, online monitoring integrated into DAQ with realtime hit map, time distribution and event hit multiplicity. It hosts a dedicated fully configurable trigger system enabling to trigger on coincidence between telescope planes and timing reference from a scintillator. The excellent time resolution performance allows for fast track reconstruction, due to the possibility to retain a low hit multiplicity per event which reduces the combinatorics. This paper reviews the architecture of the system and its performance during the 2021 and 2022 test beam campaign at the SPS North Area.

CERN

Norway

Milou Rijnbach

Giuliano Gustavino

United Kingdom

Phil Allport

Ignacio Tortajada

Germany

Dumitru Berlea

Daniela Bortoletto

Craig Buttar

Switzerland

Edoardo Charbon

Florian Dachs

Valerio Dao

Croatia

Dominik Dobrijevic

Leyre Acedo

Andrea Gabrielli

Martin Gazi

Laura Gonella

Spain

Vicente Gonzalez

Stefan Guidon

Matt LeBlanc

Heinz Pernegger

Francesco Piro

Petra Riedler

Heidi Sandaker

Abhishek Sharma

Carlos Sanchez

Walter Snoeys

Tomislav Suligoj

Marcos Nunez

Julian Weick

Steven Worm

Abdelhak Zoubir

Performance of the MALTA telescope

We study CPT-odd non-minimal Lorentz-symmetry violating couplings in the electroweak sector modifying the interactions between leptons, gauge mediators and the Higgs boson. The tree-level (differential) cross sections for three important electroweak processes are discussed: <math><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><mspace width="0.2em"></mspace><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo>→</mo><mi>Z</mi><mspace width="0.2em"></mspace><mi>H</mi></math>, <math><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><mspace width="0.2em"></mspace><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup><mo>→</mo><mi>Z</mi><mspace width="0.2em"></mspace><mi>Z</mi></math> and <math><mi>γ</mi><mspace width="0.2em"></mspace><mi>γ</mi><mo>→</mo><msup><mrow><mi>W</mi></mrow><mrow><mo>+</mo></mrow></msup><mspace width="0.2em"></mspace><msup><mrow><mi>W</mi></mrow><mrow><mo>−</mo></mrow></msup></math>. By considering next-generation <math><msup><mrow><mi>e</mi></mrow><mrow><mo>+</mo></mrow></msup><mspace width="0.2em"></mspace><msup><mrow><mi>e</mi></mrow><mrow><mo>−</mo></mrow></msup></math> colliders reaching center-of-mass energies at the TeV scale and the estimated improved precision for the measurements of the respective cross sections, we are able to project upper bounds on the purely time-like background 4-vector as strict as <math><mo>≲</mo><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>5</mn></mrow></msup><mspace width="0.25em"></mspace><msup><mrow><mtext>GeV</mtext></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></math>, in agreement with previous work on similar Lorentz-violating couplings.

Brazil

P. De Fabritiis

P.C. Malta

M.J. Neves

Lorentz-symmetry violation in the electroweak sector: Scattering processes in future  Colliders

L.P.R. Ospedal

K. Veiga

J.A. Helayël-Neto

Corrigendum to “Comparative Aspects of Spin-Dependent Interaction Potentials for Spin-1/2 and Spin-1 Matter Fields”

This paper sets out to establish a comparative study between classes of spin- and velocity-dependent potentials for spin-1/2 and spin-1 matter currents/sources in the nonrelativistic regime. Both (neutral massive) scalar and vector particles are considered to mediate the interactions between (pseudo-)scalar sources or (pseudo-)vector currents. Though our discussion is more general, we contemplate specific cases in which our results may describe the electromagnetic interaction with a massive (Proca-type) photon exchanged between two spin-1/2 or two spin-1 carriers. We highlight the similarities and peculiarities of the potentials for the two different types of charged matter and also focus our attention on the comparison between the particular aspects of two different field representations for spin-1 matter particles. We believe that our results may contribute to a further discussion of the relation between charge, spin, and extensibility of elementary particles.

Comparative Aspects of Spin-Dependent Interaction Potentials for Spin-1/2 and Spin-1 Matter Fields

We investigate the role played by particular field representations of an intermediate massive spin-1 boson in the context of spin-dependent interparticle potentials between fermionic sources in the limit of low momentum transfer. The comparison between the well-known case of the Proca field and that of an exchanged spin-1 boson (with gauge-invariant mass) described by a 2-form potential mixed with a 4-vector gauge field is established in order to pursue an analysis of spin- as well as velocity-dependent profiles of the interparticle potentials. We discuss possible applications and derive an upper bound on the product of vector and pseudo-tensor coupling constants.

F.A. Gomes Ferreira

Topologically massive spin-1 particles and spin-dependent potentials