arXiv subjects

Ulrich Heintz

Publications and source records attributed to Ulrich Heintz.

13 recordsLinked to original sources

arXiv2024

A novel internship program in HEP

The U.S. CMS collaboration has designed a novel internship program for undergraduates to enhance the participation of students from under-represented populations, including those at minority serving institutions, in High Energy Physics (HEP). These students traditionally face several barriers including lack of research infrastructure and opportunities, insufficient mentoring, lack of support networks, and financial hardship, among many others, resulting in a lack of participation in STEM fields. We had recently reported about a fully virtual 10-week internship pilot program called "U.S. CMS - PURSUE (Program for Undergraduate Research SUmmer Experience)" to address dismantling such barriers. The 2023 iteration of this program builds on it by imparting not only an in-person summer internship experience but extends it into the academic semester as well. Students are selected predominantly from Minority Serving Institutions with no research program in HEP and from under-represented groups. They experience a structured hands-on research experience with an initial two-week "bootcamp" on software training modules followed by an 8-week HEP project targeting physics analysis, software, computing or instrumentation work on the CMS Experiment. A subset of interns continue the experience into the academic semester, enabling a further in-depth knowledge of the field and a motivation to persist in STEM areas. In this paper, we describe our recent experience with this upgraded internship program. The paper is dedicated to the memory of Prof. Meenakshi Narain (Brown University) who was the driving force behind this internship program and U.S CMS diversity, equity and inclusion efforts.

physics.ed-ph↗

arXiv2022

Report of the Snowmass 2021 e$^+$e$^-$-Collider Forum

A summary of the Snowmass 2021 e$^+$e$^-$-Collider Forum discussions, white papers submitted to the Snowmass 2021 community study, submissions of the Energy Frontier (EF) subgroups and the Accelerator Frontier (AF) Integrated Task Force (ITF) are presented.

hep-ex↗

arXiv2022

Strange quark as a probe for new physics in the Higgs sector

This paper describes a novel algorithm for tagging jets originating from the hadronisation of strange quarks (strange-tagging) with the future International Large Detector (ILD) at the International Linear Collider (ILC). It also presents the first application of such a strange-tagger to a Higgs to strange ($h \rightarrow s\bar{s}$) analysis with the $P(e^-,e^+) = (-80\%,+30\%)$ polarisation scenario, corresponding to 900 fb$^{-1}$ of the initial proposed 2000 fb$^{-1}$ of data which will be collected by ILD during its first 10 years of data taking at $\sqrt{s} = 250$ GeV. Upper limits on the Standard Model Higgs-strange coupling strength modifier, $κ_s$, are derived at the 95% confidence level to be 7.14. The paper includes as well a preliminary study of a Ring Imaging Cherenkov (RICH) system capable of discriminating between kaons and pions at high momenta (up to 25 GeV), and thus enhancing strange-tagging performance at future Higgs factory detectors.

hep-ex↗

arXiv2022

End-to-End Jet Classification of Boosted Top Quarks with the CMS Open Data

We describe a novel application of the end-to-end deep learning technique to the task of discriminating top quark-initiated jets from those originating from the hadronization of a light quark or a gluon. The end-to-end deep learning technique combines deep learning algorithms and low-level detector representation of the high-energy collision event. In this study, we use low-level detector information from the simulated CMS Open Data samples to construct the top jet classifiers. To optimize classifier performance we progressively add low-level information from the CMS tracking detector, including pixel detector reconstructed hits and impact parameters, and demonstrate the value of additional tracking information even when no new spatial structures are added. Relying only on calorimeter energy deposits and reconstructed pixel detector hits, the end-to-end classifier achieves an AUC score of 0.975$\pm$0.002 for the task of classifying boosted top quark jets. After adding derived track quantities, the classifier AUC score increases to 0.9824$\pm$0.0013, serving as the first performance benchmark for these CMS Open Data samples. We additionally provide a timing performance comparison of different processor unit architectures for training the network.

physics.data-an↗

arXiv2019

End-to-end particle and event identification at the Large Hadron Collider with CMS Open Data

From particle identification to the discovery of the Higgs boson, deep learning algorithms have become an increasingly important tool for data analysis at the Large Hadron Collider (LHC). We present an innovative end-to-end deep learning approach for jet identification at the Compact Muon Solenoid (CMS) experiment at the LHC. The method combines deep neural networks with low-level detector information, such as calorimeter energy deposits and tracking information, to build a discriminator to identify different particle species. Using two physics examples as references: electron vs. photon discrimination and quark vs. gluon discrimination, we demonstrate the performance of the end-to-end approach on simulated events with full detector geometry as available in the CMS Open Data. We also offer insights into the importance of the information extracted from various sub-detectors and describe how end-to-end techniques can be extended to event-level classification using information from the whole CMS detector.

hep-ex↗

arXiv2019

Machine Learning in High Energy Physics Community White Paper

Machine learning has been applied to several problems in particle physics research, beginning with applications to high-level physics analysis in the 1990s and 2000s, followed by an explosion of applications in particle and event identification and reconstruction in the 2010s. In this document we discuss promising future research and development areas for machine learning in particle physics. We detail a roadmap for their implementation, software and hardware resource requirements, collaborative initiatives with the data science community, academia and industry, and training the particle physics community in data science. The main objective of the document is to connect and motivate these areas of research and development with the physics drivers of the High-Luminosity Large Hadron Collider and future neutrino experiments and identify the resource needs for their implementation. Additionally we identify areas where collaboration with external communities will be of great benefit.

physics.comp-ph↗

arXiv2013

Heavy Higgs Scalars at Future Hadron Colliders (A Snowmass Whitepaper)

We investigate the prospects for discovery or exclusion of additional Higgs scalars at the 14 TeV and 33 TeV LHC in the context of theories with two Higgs doublets. We focus on the modes with the largest production rates at hadron colliders, namely gluon fusion production of a heavy CP-even scalar H or a heavy CP-odd pseudoscalar A. We consider the sensitivity of the decay channels H to ZZ to 4l, and A to Zh with Z to ll and h to bb or h to tautau.

hep-ex↗

arXiv2013

Instrumentation for the Energy Frontier

The Instrumentation Frontier was set up as a part of the Snowmass 2013 Community Summer Study to examine the instrumentation R&D needed to support particle physics research over the coming decade. This report summarizes the findings of the Energy Frontier subgroup of the Instrumentation Frontier.

physics.ins-det↗

arXiv2013

Prospects for a Heavy Vector-Like Charge 2/3 Quark T search at the LHC with \sqrt{s}=14 TeV and 33 TeV. "A Snowmass 2013 Whitepaper"

We present the prospects for the discovery or exclusion of heavy vector-like charge 2/3 quarks, T, in proton-proton collisions at two center-of-mass energies, 14 and 33 TeV at the LHC. In this note, the pair production of T quark and its antiparticle, with decays to W boson and a b quark (Wb), a top quark and the Higgs boson (tH), and a top quark and Z boson (tZ) are investigated. Higgs boson decays to $b\bar b$ and $W^+W^-$ final states are selected for this study.

hep-ex↗

arXiv2012

Searches for High Mass Resonances and Exotics at the Tevatron

I review recent searches for physics beyond the standard model from the CDF and D0 experiments at the Fermilab Tevatron collider, covering searches for fourth generation quarks, exotic resonances, universal extra dimensions, and dark matter particles.

hep-ex↗

arXiv2008

Top quark mass measurements at the Tevatron

The mass of the top quark has been measured at Fermilab using the Tevatron ppbar collider to a precision of less than 1%. I discuss the individual measurements that go into this result and its impact on our understanding of the standard model of the electroweak interactions.

hep-ex↗

arXiv2001

Testing the Standard Model at the Fermilab Tevatron

In this note we study the prospect of high-precision measurements of W boson mass, top quark mass, and forward-backward asymmetry in Z->ee decays and the search for the Higgs boson during Run 2 to challenge the standard model.

hep-ph↗

arXiv2000

Precision Measurements of the W-Boson Mass

The Standard Model of electroweak interactions has had great success in describing the observed data over the last three decades. The precision of experimental measurements affords tests of the Standard Model at the quantum loop level beyond leading order. Despite this great success it is important to continue confronting experimental measurements with the Standard Model predictions as any deviation would signal new physics. As a fundamental parameter of the Standard Model, the mass of the W-boson, M_W, is of particular importance. Aside from being an important test of the SM itself, a precision measurement of M_W can be used to constrain the mass of the Higgs boson, M_H. In this article we review the principal experimental techniques for determining M_W and discuss their combination into a single precision M_W measurement, which is then used to yield constraints on M_H. We conclude by briefly discussing future prospects for precision measurements of the W-boson mass.

hep-ex↗