papers

Publications (18)

hep-ph2025

ALP Production from Abelian Gauge Bosons: Beyond Hard Thermal Loops

Mathias Becker, Julia Harz, Enrico Morgante +2

Previous computations of feebly interacting particle production have encountered issues with unphysical (negative) interaction rates at soft momenta. We address this problem by stu…

hep-ph2023

Impact of Sommerfeld Effect and Bound State Formation in Simplified -Channel Dark Matter Models

Mathias Becker, Emanuele Copello, Julia Harz +2

The existence of a dark matter model with a rich dark sector could be the reason why WIMP dark matter has evaded its detection so far. For instance, colored co-annihilation natural…

hep-ph2025

Dark matter freeze-in from non-equilibrium QFT: towards a consistent treatment of thermal effects

Mathias Becker, Emanuele Copello, Julia Harz +1

We study thermal corrections to a model of real scalar dark matter (DM) interacting feebly with a SM fermion and a gauge-charged vector-like fermion mediator. We employ the Closed-…

hep-ph2024

Impact of Bound State Formation on Baryogenesis

Mathias Becker, KÃ¥re Fridell, Julia Harz +1

The mechanism behind the generation of the baryon asymmetry of the Universe (BAU) is one of the biggest open questions of (astro-)particle physics. Popular mechanisms to generate t…

math.PR2011

Self-intersection local times of random walks: Exponential moments in subcritical dimensions

Mathias Becker, Wolfgang König

Fix , not necessarily integer, with . We study the -fold self-intersection local time of a simple random walk on the lattice up to time . This is the $p…

hep-ph2024

Confronting Dark Matter Freeze-In during Reheating with Constraints from Inflation

Mathias Becker, Emanuele Copello, Julia Harz +2

We investigate the production of particle Dark Matter (DM) in a minimal freeze-in model considering a non-instantaneous reheating phase after inflation. We demonstrate that for low…

hep-ph2020

Two-component asymmetric dark matter via bound states and freeze-in decay

Mathias Becker, Wei-Chih Huang

We propose a novel mechanism to realize two-component asymmetric dark matter of very different mass scales through bound state formation and late freeze-in decay. Assuming a partic…

hep-ph2026

Ultralight Dark Matter from the Edge of Field Space

Mathias Becker, Francesco D'Eramo, Ville Vaskonen

We introduce a novel class of bosonic dark matter candidates that we dub wallions, featuring boundaries in field space. The wallion mass is exponentially suppressed when the separa…

hep-ph2026

Sommerfeld Effect and Bound State Formation for Dark Matter Models with Colored Mediators with SE+BSF4DM

Mathias Becker, Emanuele Copello, Julia Harz +1

In the universal framework of simplified -channel dark matter models, the calculation of the relic abundance can be dominated by mediator annihilation when the dark matter and m…

hep-ph2026

Manual for SE+BSF4DM -- A micrOMEGAs package for Sommerfeld Effect and Bound State Formation in colored Dark Sectors

Mathias Becker, Emanuele Copello, Julia Harz +1

This manual describes the usage and implementation of SE+BSF4DM, an add-on package for micrOMEGAs that includes the Sommerfeld effect and bound state formation in the numerical eva…

hep-ph2021

Fermionic Singlet Dark Matter in One-Loop Solutions to the Anomaly: A Systematic Study

Mathias Becker, Dominik Döring, Siddhartha Karmakar +1

We study the dark matter phenomenology of Standard Model extensions addressing the reported anomaly in the observable at one-loop. The article covers the case of fermionic si…

hep-ph2018

Leptonic Flavor Structure in the Brane Shifted Extra Dimensional Seesaw Mechanism

Mathias Becker, Heinrich Päs

We discuss the leptonic flavor structure generated by a brane shifted extra dimensional seesaw model with a single right handed neutrino in the bulk. In contrast to previous works,…

hep-ex2022

The Forward Physics Facility at the High-Luminosity LHC

Jonathan L. Feng, Felix Kling, Mary Hall Reno +233

High energy collisions at the High-Luminosity Large Hadron Collider (LHC) produce a large number of particles along the beam collision axis, outside of the acceptance of existing L…

eess.IV2020

Spinal Metastases Segmentation in MR Imaging using Deep Convolutional Neural Networks

Georg Hille, Johannes Steffen, Max Dünnwald +3

This study's objective was to segment spinal metastases in diagnostic MR images using a deep learning-based approach. Segmentation of such lesions can present a pivotal step toward…

hep-ph2019

Dark Matter from Freeze-In via the Neutrino Portal

Mathias Becker

We investigate a minimal neutrino portal dark matter (DM) model where a right-handed neutrino both generates the observed neutrino masses and mediates between the SM and the dark s…

hep-ph2025

Multiple Soft Scatterings in Scalar Dark Matter Freeze-In

Mathias Becker, Maria Jose Fernandez Lozano, Julia Harz +1

We present an improved calculation of the freeze-in production rate for scalar dark matter (DM) from a gauge-charged parent particle via a renormalizable interaction. Building on t…

hep-ph2025

t-channel dark matter at the LHC -- a whitepaper

Chiara Arina, Benjamin Fuks, Luca Panizzi +67

This report, summarising work achieved in the context of the LHC Dark Matter Working Group, investigates the phenomenology of -channel dark matter models, spanning minimal setup…

math.PR2008

Moments and distribution of the local times of a transient random walk on

Mathias Becker, Wolfgang Konig

Consider an arbitrary transient random walk on with . Pick and let be the spatial sum of the -th power of the -step local times of…