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LumiDays 25
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Europe/Zurich
774/R-013 (CERN)
David Stickland
(Princeton University (US)),
Witold Kozanecki
(University of Oregon (US))
Description
Following the successful 2011, 2012 and 2019 workshops, we propose a new edition of the LHC LumiDays. The goal is to review the progress, since 2019 and over the first three years of Run 3, in the determination, by each Experiment, of the absolute LHC luminosity; the measurement of relevant beam parameters such as tunes, bunch populations, emittance evolution, or orbit drifts; and the characterization and mitigation of both accelerator- and luminometer-related systematic uncertainties.
This workshop will cover Run-2 results and the preliminary analyses of Run-3 data, with an emphasis on identifying studies and operational improvements that may prove useful in the upcoming last two years of Run-3 operations, or that will contribute to achieving high-accuracy luminosity determination in the early days of Run 4.
Program organization:
V. Balagura (LHCb), H. Bartosik (BE-ABP), F. Ferrari (LHCb), M. Gagliardi (ALICE), M. Gonzales-Berges (LHC-BI), M Hostettler (LHC-OP), W. Kozanecki (co-chair, ATLAS), K. Mönig (ATLAS), G. Pasztor (CMS), D. Stickland (co-chair, CMS), E. Torrence (ATLAS), J. Wanczyk (LHC-OP), C. Young (LPC)
Proceedings
Speakers should write up their contributions (1 paper per talk, no page limit but a recommended length of approximately 5 pages) using the JACoW templates.
All papers (format pdf and Word or LATeX with images) are to be uploaded directly to the Indico timetable, with as a target date the end of June 2025.
On Monday March 17 at 16:00 a Review meeting will be held in the same room at which summaries and takeaways from the workshop will be presented
Indico Link
Monday Recordings
Registration
Registration for in person attendance at LumiDays '25
Webcast
There is a live webcast for this event
Zoom Meeting ID
69411308851
Host
David Stickland
Alternative hosts
Benoit Loyer, John Cassar
Useful links
Join via phone
Zoom URL
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14:00
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15:30
Luminosity determination in Run III, and associated uncertainties: 1AConvener: Eric Torrence (University of Oregon (US))
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14:00
Welcome – workshop program, goals and scope 10mSpeaker: David Stickland (Princeton University (US))
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14:10
Overview of ATLAS luminosity determination 30m
Overview of ATLAS luminosity-determination methodology in
Run III, and comparison to Run-II methodology (both pp and HI)
Introduction to common vdM [avoid duplication in next talk!]
• Global view of:
- calibration strategy: vdM, LSC, calibration-transfer / non-
linearity corrections, instrumental corrections, ...
- long-term monitoring strategy, conceptual definition of CT +
LTS systematic uncertainties
• Description of calibration procedures (vdM scans, LSC,
calibration-transfer, instrumental corrections) & associated systs
• What was achieved; key issuesSpeaker: Brian Andrew Cole (Columbia University (US)) -
14:50
Overview of CMS luminosity determination 30m
Overview of CMS luminosity-determination methodology in
Run III, and comparison to Run-II methodology (both pp and HI)• Global view of
- calibration strategy: vdM, LSC, calibration-transfer / non-
linearity corrections, instrumental corrections, ...
- long-term monitoring strategy, conceptual definition of CT +
LTS systematic uncertainties
• Description of calibration procedures (vdM scans, LSC,
calibration-transfer, instrumental corrections) & associated systs
• What was achieved; key issuesSpeaker: Gabriella Pasztor (Eötvös University, Budapest)
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16:00
Tea/Coffee Break 30m
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17:30
Luminosity determination in Run III, and associated uncertainties: 1BConvener: Gabriella Pasztor (Eötvös University, Budapest)
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16:00
HI-specific vdM-calibration issues (ALICE Speaker) 25m
For instance: fitting procedures with challenging scan shapes;
dealing with low-statistics in scan tails; BCID-dependent satellite
corrections; satellite collisions; NF corrections; use of ZDC as
high-statistics L monitor
Include HI-specific contributions from All experimentsSpeaker: Martino Gagliardi (Universita e INFN Torino (IT)) -
16:35
ALICE final Run-II luminosity measurements 15mSpeaker: Prof. Jesus Guillermo Contreras Nuno (Czech Technical University in Prague (CZ))
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17:00
LHCb methods & techniques for luminosity measurements in pp collisions 25m
• Reminder of what was used in Run II, and main results
• brief intro to the new LHCb luminometers in Run III
• possibly some preliminary results for LHCb Run-III luminositySpeaker: Daniele Passaro (SNS & INFN Pisa (IT))
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Impact of beam dynamics on vdM calibrations: 2AConvener: Hannes Bartosik (CERN)
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09:00
Overview of the accelerator issues that impact the absolute luminosity calibrations at the LHC 30mSpeaker: Witold Kozanecki (University of Oregon (US))
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09:40
Sources & mitigation of non-factorization in the injectors & the LHC 20m
• mechanisms of generating non-factorization in the proton-density
distributions, and its transport through the injector chain
• optimized beam preparation for vdM beams — how to optimize
factorization already before the vdM fill (e.g. scraping
measurements in LHC at injection to confirm factorization, further
optimization of beam production schemes in the injectors
• collimation in the LHC?Speaker: Foteini Asvesta (CERN) -
10:10
Results of the 2024 Non-factorization MD: accelerator measurements 15mSpeaker: Elleanor Lamb
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10:30
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11:00
Coffee/Tea Break 30m
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12:30
Impact of beam dynamics on vdM calibrations: 2BConvener: Witold Kozanecki (University of Oregon (US))
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11:00
LHCb non-factorization analyses 20m
• 2-D vdM analysis
• LHCb BGI results from the NF MDSpeaker: Vladislav Balagura (Centre National de la Recherche Scientifique (FR)) -
11:30
CMS non-factorization analyses 20m
2-D vdM, beam-beam imaging and LRE analyses
• Including CMS results from the NF MD?Speaker: Peter Major (University of Maryland (US)) -
12:00
ATLAS non-factorization analyses 20m
2-D vdM and LRE analyses
• Including ATLAS results from the NF MD?
• Include some ALICE LRE results if so requestedSpeaker: Tim Barklow (SLAC National Accelerator Laboratory (US))
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Lunch 1h 30m
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Impact of beam dynamics on vdM calibrations: 2CConvener: Dr Tatiana Pieloni (EPFL)
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14:00
Summary of beam-beam simulation studies during LS2 25m
Summary of the beam-beam papers, with the emphasis on
(i) bb-related vdM uncertainties as currently understood, and
(ii) pending issuesSpeaker: Witold Kozanecki (University of Oregon (US)) -
14:35
Recent developments in beam-beam studies 20m
For instance:
• Results of the 2022 beam-beam MD
• New simulation results on Lu/L0 ambiguity
• Interplay between beam-beam & non-factorization biasesSpeaker: Joanna Wanczyk -
15:05
Generalization of parameterized beam-beam corrections to 2-D vdM scans 15mSpeaker: Ivan Kralik (Slovak Academy of Sciences (SK))
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Tea/Coffee Break 30m
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16:00
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18:20
Impact of accelerator instrumental issues on luminosity calibrations: 3AConvener: Manuel Gonzalez Berges (CERN)
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16:00
Tune measurements in vdM fills, before and during collisions 15mSpeaker: Tom Levens (CERN)
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16:20
LHC bunch-population measurements in Run III & beyond: a status report 20m
• DCCT, FBCT, BSRL: performance, issues, new developments.
• also: BPTX @ IP1 & IP5, w/ applicable functionalities; BQM
• also: 1-2 slides on planned HL-LHC upgrades of the beam
instrumentation relevant to bunch-current measurements?Speaker: Alexander Nicholas Jury (University of Liverpool (GB)) -
16:50
LHCb ghost-charge measurements 15m
• Run-III results and performance to date
• brief mention of plans for further improvementsSpeaker: Niall Thomas Mchugh (University of Glasgow (GB)) -
17:10
Numerical Tools for Studying Beam Dynamics Effects on Luminosity Calibration: COMBI and XSUITE 15m
- XSUITE: Overview and Recent Luminosity Developments
- Benchmarking Luminosity Calculations: COMBI vs. XSUITE (private version)
- First Studies on Linear Coupling (Local and Global) as an Example Case
- Potential Uses of XSUITE in Future Studies and Plans (e.g., adding the entire LHC lattice, including errors, long-range beam-beam interactions, etc.)
Speaker: Dr Tatiana Pieloni (EPFL) -
17:30
Follow-up questions and discussion 25mSpeaker: Witold Kozanecki (University of Oregon (US))
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10:30
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Impact of accelerator instrumental issues on luminosity calibrations: 3BConvener: David Stickland (Princeton University (US))
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09:00
Impact of magnetic non-linearities, BPM performance & x-y coupling on ATLAS length-scale calibrations 25m
• including the systematic. uncertainties associated w/ DOROS-
BPM performance limitations, e.g. non-reproducibility of the
BPM length scale, their response to beam-beam deflections and
their apparent out-of-plane couplingSpeaker: Richard Hawkings (CERN) -
09:35
Status report on LHC beam-position measurements at the experimental IPs 15m
• DOROS BPMs: improvements since the start of Run III,
performance, known limitations & issues
• Brief comments about Arc BPMS in the context of orbit-drift
monitoring?Speaker: Dr Marek Gasior (CERN) -
10:00
BPM- and BGI-based beam-displacement measurements at IP8 20mSpeaker: Vladislav Balagura (Centre National de la Recherche Scientifique (FR))
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09:00
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Coffee/Tea Break 30m
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Impact of accelerator instrumental issues on luminosity calibrations: 3CConvener: David Stickland (Princeton University (US))
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11:00
Emittance evolution in physics and luminosity-calibration fills: what measurements do we have and what did we learn from them? 25mSpeaker: Sofia Kostoglou (CERN)
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Luminometer non-linearities and integration uncertainties: 4AConvener: Martino Gagliardi (Universita e INFN Torino (IT))
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Uses of Emittance Scans and Planning for 25-26 15m
- How are LHC experiments and LHC Operations using Emittance scans today
- Is there a preference for early or late scans
- How frequently should they be run
- List improvements that either have been implemented in the analysis since Run II , or are definitely needed (e.g.: BB corrections, all expts), or are being dreamt about (e.g. characterization of long-range BB effects in the scans with trains)
Speaker: David Stickland (Princeton University (US)) -
11:50
Long term stability, non-linearity corrections, integration methodologies and systematic uncertainties in CMS 30mSpeaker: Francesco Romeo (Vanderbilt University)
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Lunch 1h 30m
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Luminometer non-linearities and integration uncertainties: 4BConvener: Martino Gagliardi (Universita e INFN Torino (IT))
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14:00
Calibration-transfer and long-term stability in ATLAS: corrections & systematic uncertainties. 25m
Examples of corrections that could be mentioned:
• LUCID HV adjustments based on Bi calibrations
• LUCID non-linearity correction using track-counting-based L
Examples of systematics that could be discussed:
• CT uncertainty (from TILE/tracks)
• Anchoring uncertainty
• Long-term stability & consistency uncertaintySpeaker: Giulia Ripellino (Uppsala University (SE))
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What can we do better in the remainder of Run III, and looking to Run 4: 5AConvener: Richard Hawkings (CERN)
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14:30
Use of reference physics processes for long-term relative-stability monitoring 25m
For instance:
• in pp: Z-, but also J/psi- & Upsilon- counting
• in PbPb: UPC dimuons (CMS)
• in PbPb: photonuclear signatures in the ZDCsSpeaker: David Walter (Massachusetts Inst. of Technology (US)) -
15:05
New LHCb luminometers in Run III 20m
what has LHCB learnt from PLUME (and other luminometers) in
Run III, and how it informs the LHCb strategy for Run 4Speaker: Edoardo Franzoso (Universita e INFN, Ferrara (IT))
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14:30
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Tea/Coffee Break 25m
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16:00
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What can we do better in the remainder of Run III, and looking to Run 4: 5BConvener: Richard Hawkings (CERN)
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16:00
Looking to Run 4: ATLAS Run-3 experience with LUCID prototypes for HL- LHC 20mSpeaker: Vincent Hedberg (Lund University (SE))
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16:30
Looking to Run 4 in CMS 20m
For instance (under consideration; not an exhaustive list):
• experience with BCM1F in Run 3, and how it informs the CMS
strategy for Run 4
• proposal for very-high µ (µ > 120) fill with a mixture of indivs &
trains (as done in 2016) for characterizing the BCID-dependent
response, and the relative µ-dependence, of the CMS
luminometers (also of interest to ATLAS)
• scouting
• outer-tracker potential for L monitoring in Run 4 (simulation
results)Speaker: Alexey Shevelev (University of Maryland (US)) -
17:00
Discussion and Closeout 10m
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