A
bstract
The Light Dark Matter eXperiment (LDMX) is an electron-beam fixed-target experiment designed to achieve comprehensive model independent sensitivity to dark matter particles in the sub-GeV ...mass region. An upgrade to the LCLS-II accelerator will increase the beam energy available to LDMX from 4 to 8 GeV. Using detailed GEANT4-based simulations, we investigate the effect of the increased beam energy on the capabilities to separate signal and background, and demonstrate that the veto methodology developed for 4 GeV successfully rejects photon-induced backgrounds for at least 2
×
10
14
electrons on target at 8 GeV.
A
bstract
Fixed-target experiments using primary electron beams can be powerful discovery tools for light dark matter in the sub-GeV mass range. The Light Dark Matter eXperiment (LDMX) is designed to ...measure missing momentum in high-rate electron fixed-target reactions with beam energies of 4 GeV to 16 GeV. A prerequisite for achieving several important sensitivity milestones is the capability to efficiently reject backgrounds associated with few-GeV bremsstrahlung, by twelve orders of magnitude, while maintaining high efficiency for signal. The primary challenge arises from events with photo-nuclear reactions faking the missing-momentum property of a dark matter signal. We present a methodology developed for the LDMX detector concept that is capable of the required rejection. By employing a detailed Geant4-based model of the detector response, we demonstrate that the sampling calorimetry proposed for LDMX can achieve better than 10
−
13
rejection of few-GeV photons. This suggests that the luminosity-limited sensitivity of LDMX can be realized at 4 GeV and higher beam energies.
Building a Distributed Computing System for LDMX Bryngemark, Lene Kristian; Cameron, David; Dutta, Valentina ...
EPJ Web of Conferences,
01/2021, Letnik:
251
Conference Proceeding, Journal Article
Recenzirano
Odprti dostop
Particle physics experiments rely extensively on computing and data services, making e-infrastructure an integral part of the research collaboration. Constructing and operating distributed computing ...can however be challenging for a smaller-scale collaboration. The Light Dark Matter eXperiment (LDMX) is a planned small-scale accelerator-based experiment to search for dark matter in the sub-GeV mass region. Finalizing the design of the detector relies on Monte-Carlo simulation of expected physics processes. A distributed computing pilot project was proposed to better utilize available resources at the collaborating institutes, and to improve scalability and reproducibility. This paper outlines the chosen lightweight distributed solution, presenting requirements, the component integration steps, and the experiences using a pilot system for tests with large-scale simulations. The system leverages existing technologies wherever possible, minimizing the need for software development, and deploys only non-intrusive components at the participating sites. The pilot proved that integrating existing components can dramatically reduce the effort needed to build and operate a distributed e-infrastructure, making it attainable even for smaller research collaborations.
Baryon number violation in supersymmetry Calibbi, Lorenzo; Ferretti, Gabriele; Milstead, David A. ...
The journal of high energy physics,
2016, Letnik:
5, Številka:
5
Journal Article
Recenzirano
Odprti dostop
We study baryon number violation in R-parity violating supersymmetry with focus on Delta B = 2 processes which allow neutron-anti-neutron (n - (n) over bar) oscillations. We provide prospects for ...going beyond the present limits by means of a new search for n oscillations. The motivation is the recently proposed n - (n) over bar oscillation experiment at the European Spallation Source in Lund, which is projected to be able to improve the current bound on the transition probability in the quasi-free regime by three orders of magnitude. We consider various processes giving rise to baryon number violation and extract the corresponding simplified models, including only the relevant superpartners and couplings. In terms of these models we determine the exclusion limits from LHC searches as well as from searches for flavor transitions, CP violation and di-nucleon decays. We find that, for certain regions of parameter space, the proposed n - (n) over bar experiment has a reach that goes beyond all other experiments, as it can probe gluino and squark masses in the multi-TeV range.
A
bstract
We study baryon number violation in
R
-parity violating supersymmetry with focus on Δ
B
= 2 processes which allow neutron-anti-neutron (
n
−
n
¯
) oscillations. We provide prospects for ...going beyond the present limits by means of a new search for
n
−
n
¯
oscillations. The motivation is the recently proposed
n
−
n
¯
oscillation experiment at the European Spallation Source in Lund, which is projected to be able to improve the current bound on the transition probability in the quasi-free regime by three orders of magnitude. We consider various processes giving rise to baryon number violation and extract the corresponding simplified models, including only the relevant superpartners and couplings. In terms of these models we determine the exclusion limits from LHC searches as well as from searches for flavor transitions, CP violation and di-nucleon decays. We find that, for certain regions of parameter space, the proposed
n
−
n
¯
experiment has a reach that goes beyond all other experiments, as it can probe gluino and squark masses in the multi-TeV range.
Various models for new physics not described by the Standard Model predict event topologies with large missing transverse energy due to invisible new particles. Such events can be identified in the ...detector if they are accompanied by an energetic photon or a jet with high transverse energy. This article presents results from searches for new physics with both signatures in proton-proton collision data with the ATLAS detector at the LHC. The focus is on the analyses using the full 2011 data set with an integrated luminosity of at a center of mass energy of TeV but the article also includes an update of the monojet analysis with of data recorded in 2012 at TeV. The results are translated into exclusion limits on parameters of different theoretical models.
(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image) Abstract We study baryon number violation in R-parity violating supersymmetry with focus on DeltaB = 2 processes which ...allow neutron-anti-neutron (n - ...) oscillations. We provide prospects for going beyond the present limits by means of a new search for n - ... oscillations. The motivation is the recently proposed n - ... oscillation experiment at the European Spallation Source in Lund, which is projected to be able to improve the current bound on the transition probability in the quasi-free regime by three orders of magnitude. We consider various processes giving rise to baryon number violation and extract the corresponding simplified models, including only the relevant superpartners and couplings. In terms of these models we determine the exclusion limits from LHC searches as well as from searches for flavor transitions, CP violation and di-nucleon decays. We find that, for certain regions of parameter space, the proposed n - ... experiment has a reach that goes beyond all other experiments, as it can probe gluino and squark masses in the multi-TeV range.
Particle physics experiments rely extensively on computing and data services, making e-infrastructure an integral part of the research collaboration. Constructing and operating distributed computing ...can however be challenging for a smaller-scale collaboration.
The Light Dark Matter eXperiment (LDMX) is a planned small-scale accelerator-based experiment to search for dark matter in the sub-GeV mass region. Finalizing the design of the detector relies on Monte-Carlo simulation of expected physics processes. A distributed computing pilot project was proposed to better utilize available resources at the collaborating institutes, and to improve scalability and reproducibility.
This paper outlines the chosen lightweight distributed solution, presenting requirements, the component integration steps, and the experiences using a pilot system for tests with large-scale simulations. The system leverages existing technologies wherever possible, minimizing the need for software development, and deploys only non-intrusive components at the participating sites. The pilot proved that integrating existing components can dramatically reduce the effort needed to build and operate a distributed e-infrastructure, making it attainable even for smaller research collaborations.
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