Roadmap of Dark Matter models for Run 3

13 May 2024, 09:00 → 17 May 2024, 18:00 Europe/Zurich

40/S2-D01 - Salle Dirac (CERN)

Daniel Johnson (University of Birmingham (GB)), Deborah Pinna (University of Wisconsin Madison (US)), James Frost (University of Oxford (GB)), Matteo Cremonesi (Carnegie-Mellon University (US)), Spyros Argyropoulos (Albert Ludwigs Universitaet Freiburg (DE)), Tim M.P. Tait (University of California, Irvine), Uli Haisch, Xabier Cid Vidal (Instituto Galego de Física de Altas Enerxías), Zirui Wang (University of Michigan (US))

The main goals of this workshop are to discuss

• signatures which have not been explored (or only poorly explored) until Run 2 (new final states, final states with unusual objects, final states which require developing new triggers/selections/experimental techniques)
• ways to improve the interpretations of currently used DM benchmarks (update of parameter scans, new parameter scans, etc.)
• interplay with other experiments (LLP, low-mass signatures, etc.)

 

Videoconferencing

 

To access the zoom link and password you have to log in with your CERN credentials. The zoom link is accessible via the left menu under "Videoconferencing" or by clicking on "Timetable (indico style)".

 

Workshop dinner

 

The workshop dinner will take place on May 15th at CAFÉ HORTUS (https://cafehortus.ch/), just a short two-stop tram ride away from CERN.
Both regular and vegan menus are available. 

 

Please be aware that the restaurant does not accept separate payments for menu options. For colleagues who have completed the survey (https://indico.cern.ch/event/1340162/surveys/5247) and selected their menu options, we kindly request that they bring cash (65 CHF per person) for payment at the beginning of Tuesday morning sessions to Zirui Wang.

 

Access to the CERN site

Visitor badges will be provided automatically to people who do not have a CERN access card. Please indicate in the registration form whether you will need a badge.

 

Fees

The workshop is cost-free.

 

Travel and accommodation

Please make your own travel arrangements and book your accommodation early on. 

Note: If you receive any email offering you accommodation for the event, e.g. from "Global Travel Experts" please ignore it - this is a well-known scam targeting registrants of indico events.

 

CERN Webcam Policy - Speakers Release.pdf

GroupPhoto_2024LHCDMWGWorkshop.jpg

PosterLHCDMWG.pdf

Monday, 13 May

09:00 → 14:00 Arrival

14:00 → 14:10 Welcome

14:00 Organisational details

Speaker: Spyros Argyropoulos (Albert Ludwigs Universitaet Freiburg (DE))

Organisation.pdf

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14:10 → 18:20 LLP signatures

Conveners: Dean Robinson (Lawrence Berkeley National Laboratory (LBL)), Juliette Alimena (DESY), Dr Louie Corpe (Laboratoire de Physique Clermont Auvergne (LPCA))

14:20 LLP-DM overview: linking searches to models, and LLP experiment reach for DM model space

Speaker: David Curtin (University of Toronto)

davidcurtin_DM-LLP-connection_LHCLLP_2024.05.13_20m_v1.pdf

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14:55 Multiple track signatures

Speaker: Jackson Carl Burzynski (Simon Fraser University (CA))

Burzynski_LLPMultipleTrack_LHCDM.pdf

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15:20 Signatures with MET

Speaker: Joseph Reichert (Rutgers State Univ. of New Jersey (US))

2024-05-13 DM Workshop LLP Signatures with MET.pdf

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15:45 Pair-produced LLPs (to jets, leptons, photons...)

Speaker: Audrey Katherine Kvam (University of Massachusetts (US))

PairProducedLLP_Kvam.pdf

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16:10 Coffee break

16:45 Mass-independent searches

Speaker: Christina Wenlu Wang (California Institute of Technology (US))

Run3_DMworkshop_2024_CW.pdf

17:05 Recasting wishlist

Speakers: Prof. Andre Lessa (CCNH - Univ. Federal do ABC), Andre Lessa (IFGW - UNICAMP)

DMwokshop2024_LLPs.pdf

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17:30 Update on the CODEX-b Experiment

The High Luminosity LHC will be a tremendous opportunity to search for long lived particles (LLPs) from an extended hidden/dark sector, feebly connected to the known SM sector. Such LLP searches will require special detectors, placed far away from the proton-proton collision point and shielded against SM backgrounds. The CODEX-b detector, to be placed behind a thick shielding wall inside the LHCb cavern, around 25m from the LHCb interaction point, provides a novel solution. On the journey to construction of the full detector, a demonstrator (CODEX-𝛽) is foreseen for installation and operation during LHC Run 3. This talk will present the latest developments and will focus on the status and plans for CODEX-𝛽.

Speaker: Louis Henry (EPFL - Ecole Polytechnique Federale Lausanne (CH))

20240513_CodexB.pdf

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17:50 Discussion

Speaker: Dr Louie Dartmoor Corpe (Laboratoire de Physique Clermont Auvergne (LPCA))

Tuesday, 14 May

09:00 → 12:30 Unexplored signatures & wildcard ideas

Conveners: Alexander Grohsjean (Hamburg University (DE)), Giuliano Gustavino (Sapienza Universita e INFN, Roma I (IT)), Monika Blanke (Karlsruhe Institute of Technology)

09:00 A smoking gun signature of the 3HDM [20+10]

Speaker: Dr Atri Dey (Dublin Institute for Advanced Studies)

Recording

roadmap_of_DM_Atri.pdf

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09:30 Fermionic Portal to Vector Dark Matter [20+10]

We suggest a new class of models - Fermionic Portal Vector Dark Matter (FPVDM) which extends the Standard Model (SM) with SU(2)_D dark gauge sector. While FPVDM does not require kinetic mixing and Higgs portal. It is based on the Vector-Like (VL) fermionic doublet which couples the dark sector with the SM sector through the Yukawa interaction. The FPVDM framework provides a vector Dark Matter (DM) with Z_2 odd parity ensuring its stability. Multiple realisations are allowed depending on the VL partner and scalar potential, which explain not only DM but also could provide solutions of various BSM hints, including (g-2)_mu, flavour anomalies, W-boson mass measurement by CDF, etc.

Two examples will be discussed. One of them is the FPVDM realisation with only a VL top partner, which provides interesting and promising implications for DM direct and indirect detection experiments, relic density and collider searches. Another realisation of the FPDM framework with a doublet of new vector-like partners of muon can simultaneously explain DM relic density together with (g-2)_mu anomaly which has been in close focus of the HEP community over two decades. It predicts the mass of vector DM to be below GeV as well as the mass of the muon partner to be below 1 TeV, and provides novel multi-lepton signatures at the LHC.

The talk is based on 2203.04681, 2204.03510 arXiv papers as well as the new one which is coming this March-April.

Speaker: Prof. Alexander Belyaev (University of Southampton & Rutherford Appleton Laboratory)

Belyaev-FPVDM-CERN-DM-MODELS-WORKSHOP-MAY2024.pdf

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10:00 Inelastic Dark Matter at the LHC Lifetime Frontier [20+10]

Speaker: Max Fieg (University of California Irvine (US))

InelasticDMAtLHC_Fieg.pdf

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10:30 Search for Dark Matter with Anomaly Detection Techniques [20+10]

Speaker: Thea Aarrestad (ETH Zurich (CH))

ad_for_dm.pdf

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11:00 Coffee Break

11:30 Production of Kaluza-Klein States at LHC and Implication for Dark Matter [12+3]

t has been proposed that, in the large radius compactification (LRC) scenario, the Kaluza-Klein states might be considered as dark matter (DM) candidates. The universal extra dimension (UED) hypothesis, together with the LRC paradigm, holds the prospect of observing KK states at LHC if masses lie in the accessible LHC energy scale. If observed, they might be possible DM candidates, provided LKP is protected by a conservation law not to decay to SM particles. This work is based on axiomatic field theory approach to derive upper bound on production cross sections and bounds on near forward differential cross sections. These bounds are obtained without appealing to perturbation theory, i.e. cross-section bounds are obtained nonperturbatively. The bounds are based on principles of local field theories such as Lorentz invariance, causality and uniqueness of vacuum (respected by all local field theories). We shall depict the growth properties of relevant cross sections as a function of energy. It is speculated that KK states might be observed in cosmic ray experiments.

Speaker: Jnanadeva Maharana (National Institute of Science Education and Research (IN))

cern-dm24.pdf

11:45 Search for Anti Quark Nuggets via their interaction with the LHC beam: A reanalysis of stored data from the 4000 LHC monitors [12+3]

Anti-quark nuggets, AQNs, (ZHITNITSKY, 2003), have been suggested to solve the dark matter (DM) and the missing antimatter problem in the universe, and have been proposed as an explanation of various observations.

Their size is in the μm range and their density equal to the nuclear density with an expected flux of about 1 / km2 / year. For the typical velocity of DM constituents (~250 km/s), the solar system bodies act as highly performing gravitational lenses; Here we assume that DM streams or clusters are impinging, e.g., on the Earth, as was worked out for DM axions and WIMPs.

Interestingly, in the LHC beam, unforeseen beam losses are triggered by so-called UFOs (Unidentified Falling Objects), which are believed to be constituted of dust particles with a size in the μm range and a density several orders of magnitude lower than AQNs.

Prezeau suggested that streaming DM constituents incident on the Earth should result in jet-like structures (“hairs”) exiting the Earth. Such ideas open up novel directions in the search for DM.

This talk suggests a new analysis of the UFO results at the LHC, assuming that they are eventually, at least partly, due to AQNs. Specifically, a reanalysis of the existing data from the ~4000 beam monitors since the beginning of the LHC is proposed, arguing that dust and AQNs should behave differently. The feasibility of this idea has been discussed with three CERN accelerator experts and other collaborators.

Speaker: Konstantin Zioutas (University of Patras (GR))

DM WORKSHOP 14052024 CERN KZ xX.pdf

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12:00 The Triggerless Search for Exotic DM at Run-3 with the MoEDAL-MAPP Experiment [12+3]

The MoEDAL-MAPP experiment at Run-3 incorporates the MoEDAL and MAPP-1 (MoEDAL Apparatus for Penetrating Particles) detectors deployed at IP8 and in the UA83 tunnel on the LHC Ring, respectively. The passive, triggerless, MoEDAL detector has been taking data at Run-1 and Run-2 and is a world leader in the direct search for Highly Ionizing Particles (HIPs) at a Collider. HIP avatars of new physics include several exotic dark matter candidates including magnetic monopoles, Q-balls, nuclearites, microscopic black-hole remnants and lepton-like multi-charged constituents of composite dark matter, etc.

The MAPP-1 detector is currently being installed on the LHC ring and is primarily designed to search for Weakly Ionizing Particle (WIPs) messengers of new physics. However, it also has sensitivity to very long-lived charged and neutral particles (LLPs) exemplars of physics beyond the Standard Model, decaying to charged and photonic states. The MAPP-1 data acquisition rate is low enough that all data can be stored subject to optional “software a trigger” cuts. In this sense MAPP-1 is triggerless. The MAPP-1 detector will also be used in the search for exotic DM messengers of new physics such as: millicharged particles, light neutralinos and sterile neutrinos.

Speaker: James Pinfold (University of Alberta (CA))

DM-workshop-CERN-2024-new.pdf

12:15 Wrap-up and Discussion

Speaker: Spyros Argyropoulos (Albert Ludwigs Universitaet Freiburg (DE))

12:30 → 14:00 Lunch break

14:00 → 18:05 s-channel mediators and Higgs to invisible

Conveners: Katherine Pachal (TRIUMF (CA)), Patrick James Fox, Philip Coleman Harris (Massachusetts Inst. of Technology (US))

RoadmapBenchmarks.pdf

14:00 ATLAS Higgs to invisible plans and summary

Speaker: Diallo Boye (Brookhaven National Laboratory)

Recording

Roadmap_DM_Run3.pdf

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14:30 CMS Higgs to invisible plans and summary

Speaker: Andrea Malara (Universite Libre de Bruxelles (BE))

24_05_15_LHC_DM_Hinv_CMS.pdf

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15:00 ATLAS & CMS legacy s-channel results

Speaker: Matteo Bauce (Sapienza Universita e INFN, Roma I (IT))

LHCDMWG_workshop24_Bauce.pdf

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15:30 New experimental directions for s-channel

Speaker: David Yu (University of Nebraska Lincoln (US))

Recording

Slides_240514_schan.pdf

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16:00 Coffee break

16:30 EFT theory for Higgs to invisible

Speaker: Prof. Pyungwon Ko (KIAS (Korea Institute for Advanced Study))

DM@LHC Run3_2024_ko.pdf

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17:00 Beyond the Dark matter effective field theory and a simplified model approach at colliders

In this talk, I will review the importance of "Gauge invariance" in the search for Dark matter at the High Energy Collider including LHC.

The major topics I will include will be
1) The limit of effective field theory / simplified model approach at the High Energy collider
2) Dark matter showering at the High Energy collider

Speaker: Prof. Myeonghun Park (Seoultech)

PARK_CERN.pdf

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17:25 Is the light neutralino thermal dark matter in the pMSSM ruled out?

We explore the parameter space of the phenomenological Minimal Supersymmetric Standard Model (pMSSM) with a light neutralino thermal dark matter (M ̃χ01 ≤ Mh/2) that is consistent with current collider and astrophysical constraints. We identify that a narrow region with light Higgsinos having masses between 125-160 GeV survives the present constraints for the μ < 0 scenario, including the electroweakino searches implemented in recast frameworks like SModelS and CheckMATE, where μ is the Higgsino mass parameter. This hints towards either a gap in the present LHC searches or the unavailability of its proper recasting. We select benchmarks from this region, and our analysis using the machine learning framework of XGBOOST shows that these are well within the reach of the Run-3 of LHC, and dedicated efforts to probe this region should be pursued. We observe that the recent experimental results from the LHC and direct detection searches for dark matter by the LUX-ZEPLIN collaboration put the μ > 0 scenario under severe tension. We further investigate the impact of light staus on the parameter space, provide benchmarks that can be interesting for Run-3 of LHC, and analyse these benchmarks at the LHC using XGBOOST. Finally, we also discuss the effect of non-standard cosmology on the parameter space.

Speaker: Rhitaja Sengupta (BCTP and Physikalisches Institut der Universität Bonn, Germany)

Recording

Roadmap_pMSSM.pdf

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17:50 Darkonia at Colliders

Dark matter bound states may exist within the dark sector, characterized by a substantial dark force. Depending on the spins and parity properties of the force carriers, Standard Model particles may primarily couple with either the lowest or excited bound states. We discuss the associated collider signatures at the LHC for various simplified models.

Speaker: Yang Bai

Darkonia_YangBai.pdf

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Wednesday, 15 May

09:00 → 13:00 Extended Higgs sectors

Conveners: Priscilla Pani (Deutsches Elektronen-Synchrotron (DE)), Uli Haisch

2HDM+a open questions

09:00 Experimental introdution to extended higgs models: an ATLAS perspective (20'+10')

Speaker: Janna Katharina Behr (Deutsches Elektronen-Synchrotron (DE))

2HDMa_ATLAS_JKBehr.pdf

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09:30 Experimental introdution to extended higgs models: a CMS perspective (20'+10')

Speaker: Danyer Perez Adan (RWTH Aachen University (DE))

2HDMa-CMS_DanyerPerezAdan.pdf

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10:00 Theory introduction to extended higgs models: a collider perspective (20'+10')

Speakers: Jose Miguel No Redondo (Conseil Europeen Recherche Nucl. (CERN)-Unknown-Unknown), Jose Miguel No Redondo

2024_LHCDMWG_JMNo_Final.pdf

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10:30 Theory introduction to extended higgs models: a dark matter phenomenology perspective (20'+10')

Speakers: Giorgio Busoni (The University of Melbourne), Giorgio Busoni (The Australian National University)

LHCDM24_Busoni.pdf

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11:00 coffee break

11:30 Extended Higgs Sector in Singlet-Triplet Fermionic Model for Dark Matter and Neutrino Mass (12'+3')

Speaker: Dr Manimala Mitra (Institute of Physics (IOP))

LHCDMWG-Manimala.pdf

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11:45 Sensitivity of 2HDMa searches to Inert Doublet Model (12'+3')

Speaker: Dr Jayita Lahiri (II. Theoretical Institute for Physics, University of Hamburg)

LHCDMWG_Jayita.pdf

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12:00 Novel signatures in the Type-I 2HDMa model (12'+3')

The 2HDMa model is one of the main models used in the Dark Matter searches at the LHC. So far, all the 2HDMa benchmarks used by the LHC experiments feature a Type-II Yukawa sector with degenerate Higgses ($m_A=m_H=m_{H^{\pm}}$). The latter implies, together with the fact that flavour observables put lower bounds on the mass of the charged Higgses, that the $A/H/H^{\pm}$ bosons are all constrained to be heavy ($\gtrsim 600$ GeV).
In this talk, we present the first detailed study of a 2HDMa model with a Type-I Yukawa sector, which, for moderate values of $\tan\beta$, lifts the constraints from flavour observables, allowing the extra Higgs bosons to be even lighter than the SM Higgs boson. We discuss four benchmarks with degenerate and non-degenerate Higgses and the signatures that arise in this model, some of which have not yet been explored by the LHC experiments. The talk will present the dominant channels in these benchmarks and the expected sensitivity in Run 2 data using a truth-level analysis and will discuss potential improvements in the experimental searches for Run 3.

Speaker: Ilia Kalaitzidou (Albert Ludwigs Universitaet Freiburg (DE))

LHCDMWG24_IliaKalaitzidou.pdf

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12:15 Panelist discussion (invited speakers + session chairs) (45')

Speaker: Spyros Argyropoulos (Albert Ludwigs Universitaet Freiburg (DE))

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13:00 → 14:00 Lunch break

14:00 → 18:00 Low mass signatures, ALPs, dark photons

Conveners: J Michael Williams (Massachusetts Inst. of Technology (US)), Philip Ilten (University of Cincinnati (US)), Zirui Wang (University of Michigan (US))

14:00 Dark Photon Searches on LHCb (20'+10')

Speaker: Adrian Casais Vidal (Massachusetts Institute of Technology (MIT))

Dark Photons.pdf

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14:30 Dark Photon Searches on CMS (20'+10')

Speaker: Elisa Fontanesi (Boston University (US))

CMSDarkPhotonResults_2024May15_EF.pdf

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15:00 Dark Photon Searches on ATLAS (20'+10')

Speaker: Hassnae El Jarrari (CERN)

HassnaeElJarrariDarkPhotonATLAS2024.pdf

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15:30 Recasting Dark Photon Searches (20'+10')

Speaker: Yotam Soreq (Technion- Israel Institute of Technology (IL))

2024_05_Roadmap_DM_01.pdf

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16:00 Coffee break

16:30 Mono-X Signatures of a Fermionic Dark Matter at the LHC (15'+5')

Speaker: Kai Ma (Shaanxi University of Technology)

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talkHamate.pdf

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16:50 Dark Photon Theory Landscape (25'+10')

Speaker: Stefania Gori (UC Santa Cruz)

Recording

TalkCERN.pdf

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17:25 Dark Photon Exploration Beyond the LHC (25'+10')

Speaker: Bertrand Echenard (California Institute of Technology (US))

LHCDMWG-echenard.pdf

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Thursday, 16 May

09:00 → 12:30 t-channel mediators

Conveners: Benedikt Maier (KIT - Karlsruhe Institute of Technology (DE)), Benjamin Fuks

09:00 Cosmological perspectives and constraints on t-channel models [20'+10']

Speaker: Chiara Arina (CP3 UCLouvain)

Chiara_Arina_t_channel_cosmo.pdf

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09:30 A theory overview on t-channel models and their LHC phenomenology [30'+10']

Speaker: Luca Panizzi (Uppsala University)

DMtsimp_collider.pdf

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10:10 LHC Signatures of Flavoured Dark Matter [25'+10']

Speaker: Monika Blanke (Karlsruhe Institute of Technology)

Blanke_DM_roadmap.pdf

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10:45 Coffee break

11:15 Experimental bounds on t-channel models with heavy flavours [15'+5']

Speaker: Deborah Pinna (University of Wisconsin Madison (US))

DarkMatter_LHC_DMWG_DP.pdf

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11:35 Long-lived particles and t-channel models [20'+10']

Speakers: Dr Jan Heisig (Université catholique de Louvain (UCL)), Jan Heisig

Heisig_DMWG_CERN_WS.pdf

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12:05 t-channel dark matter, flavour anomalies and top flavour-changing neutral currents [20'+5']

Speaker: Dr Adil Jueid (Institute for Basic Science)

main.pdf

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12:20 Discussion

Speaker: Benjamin Fuks

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12:30 → 14:00 Lunch break

14:00 → 18:00 Dark Higgs

Conveners: Felix Kahlhoefer (Karlsruhe Institute of Technology), Matteo Cremonesi (Carnegie-Mellon University (US))

14:00 Theory and Motivation of dark Higgs Bosons [25+5]

Speaker: Dr Giorgio Arcadi (University of Messina (Italy))

DM_Roadmaps_arcadi.pdf

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14:30 Searches for Dark Higgs Bosons at ATLAS [15+5]

Speaker: Mr Changqiao Li (Max Planck Society (DE))

Recording

TalkAtLHCDMWS.pdf

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14:50 Searches for Dark Higgs Bosons at CMS [15+5]

Speakers: Alicia Calderon Tazon (Universidad de Cantabria and CSIC (ES)), Alicia Calderon tazon

DMWorkshopLHC_CMS_16May2024.pdf

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15:10 Review of Benchmark Models Used for Z'+MET Searches [15+5]

We present a review of the models used for the search for a new leptonically decaying neutral vector boson in association with missing transverse energy by ATLAS, which was published as a conference note (ATLAS-CONF-2023-045) in August 2023. Three signal regions were defined as bins in the $\text{E}_\text{T}^{\text{miss}}$ significance, and the search was performed by scanning across the dilepton invariant mass spectrum in each of these regions. No significant excess above the expected Standard Model background was observed, and limits were set on two benchmark models referred to as light-vector and dark-Higgs. It has been established that the particular benchmarks used in this search do not reproduce the observed dark-matter relic density, and we investigate possibilities for adjusting the models to satisfy the relic-density constraints. We also consider the impact on these models from other search constraints, in particular the $s$-channel constraints from the dark-matter summary effort by ATLAS (ATL-PHYS-PUB-2023-018), which for example includes limits from the inclusive dilepton and dijet searches. Plans are also made to provide fiducial cross-section limits for the signal regions used in the search in order ease reinterpretations of the search, but it is at the moment unclear if these limits will be available in time for this presentation.

Speaker: Even Simonsen Haaland (University of Oslo (NO))

Recording

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ZpMET_LHCDMWG_May2024.pdf

15:30 Coffee break

16:00 Searches for Extra Higgs Bosons and the 95 GeV Excess [25+5]

Speaker: Thomas Biekötter

Recording

slides.pdf

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16:30 Light Higgs Bosons ATLAS+CMS [15+5]

Speaker: Pallabi Das (Princeton University (US))

LightHiggsBosons.pdf

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16:50 Search for inelastic dark matter in association with a dark Higgs boson at Belle II [15+5]

Belle II has a unique reach for a broad class of models that postulate the existence of dark matter particles in the MeV-GeV mass range. One scenario is a model which involves inelastic dark matter, consisting of two dark matter states with a mass splitting between them and the presence of a dark Higgs boson. This model has a signature of up to two displaced vertices, one from the resonant decay of the dark Higgs and another non-resonant one emerging from the decay of the involved dark matter particles. This talk will present studies of an ongoing search for such signatures using Belle II simulation, which is not only challenging due to the presence of displaced vertices but also because of the seven-dimensional parameter space of the model.

Speaker: Patrick Ecker

2024_05_16_idmdh_at_belle2.pdf

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17:10 Discussion Session - Presentation of Dark Higgs Results

Speaker: Felix Kahlhoefer (Karlsruhe Institute of Technology)

Discussion.pdf

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Friday, 17 May

09:00 → 13:00 Dark showers

Conveners: Annapaola De Cosa (ETH Zurich (CH)), Suchita Kulkarni (University of Graz), Sukanya Sinha (University of Manchester (GB))

09:00 Introduction

Speakers: Annapaola De Cosa (ETH Zurich (CH)), Suchita Kulkarni (University of Graz), Sukanya Sinha (University of Manchester (GB))

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09:05 Strongly-interacting dark sectors and DM relic density: an overview

Speaker: Felix Kahlhoefer (Karlsruhe Institute of Technology)

SIMPs.pdf

09:35 Experimental results: ATLAS

Speaker: Dilia Maria Portillo Quintero (TRIUMF (CA))

DarkShowers_inATLAS_DJR_Roadmap_CERN_March2024 wBackups.pdf

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09:55 Experimental results: CMS

Speaker: Long Wang (University of Maryland (US))

dark showers searches in CMS.pdf

dark showers searches in CMS.pptx

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10:15 Reinterpretation of CMS emerging jets for Higgs-mediated dark showers

In this talk we will present the reinterpretation of the CMS emerging jets (that is, long-lived dark pions belonging to a strongly interacting dark sector), published in JHEP 01 (2024) 034 (arXiv:207.04847) and will show that particularly this search can set meaningful bounds on scenarios where the SM Higgs boson mediates between the visible and dark sectors. In particular we find that for dark pion lifetimes between 5-100 mm the reintepretation of this search, while suboptimal, would be more sensitive than the extrapolation of the BSM Higgs search (2.5 - 4 %, depending on the assumed systematics).

Hence, this talk combines:

a) dark showers, and in particular emerging jets, which is a LLP signature subset (and how to reinterpretate them)
b) s-channel mediators (the Higgs)
c) Higgs to invisible (or actually to "undetected", as we do expect the dark pions to decay into the SM).

Speaker: Dr José Francisco Zurita (IFIC - Univ. of Valencia and CSIC (ES))

Recording

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Zurita_EJ_recasting.pdf

10:30 Exploration of b-philic SVJ and new discriminating observables

After the first round of SVJ experimental results, the focus has shifted to exploring more specific topologies, as well as attempts to design more sensitive observables. In this presentation, we will cover an exploratory study of SVJs produced preferentially with bottom quarks, including looking at the sensitivity from current public results. The advantage of using variable radius jets will be discussed. In the second part, we will cover our attempts to discriminate SVJs better, by designing observables less sensitive to specifics of Pythia8 HV modelling.

Speaker: Deepak Kar (University of the Witwatersrand (ZA))

dkar-lhcdmwg.pdf

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10:45 Coffee

11:15 Dark sector glueballs

Speaker: Caleb Gemmell (University of Toronto)

gemmell_LHCDMWG.pdf

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11:40 Probing new signatures for semi-visible jets at the LHC

The Hidden Valley scenario consists of a set of models where the Standard Model is accompanied by a Hidden Sector and connected with it via a heavy mediator or a weak coupling. If realised in nature, the Hidden Valley scenario may result in unusual and little-studied phenomena at the LHC. Under the assumption of a QCD-like confining dark sector, novel experimental signatures emerge, characterized by sprays of particles resembling hadronic jets containing stable invisible dark matter bound states. The resulting signature is characterised by missing momentum aligned with one of the jets, defining an orthogonal phase-space compared to traditional WIMPs searches. These semi-visible jets have been studied theoretically and experimentally in the fully hadronic signature where the unstable composite dark bound states can only decay promptly back to Standard Model quarks. We present a set of new simplified models allowing the decays of the unstable dark bound states to leptons, photons and b-quarks. The new resulting signatures are semi-visible jets characterised by an enhanced presence of non-isolated leptons or photons, coming directly from dark bound states decays or from subsequent decays of tau leptons or B mesons. We discuss possible constraints from previous searches from the CMS and ATLAS experiments, as well as propose possible realistic analysis strategies for Run2 and Run3 leveraging the enhanced leptonic or photon content of these anomalous jets.

Speaker: Cesare Tiziano Cazzaniga (ETH Zurich (CH))

presentation_LHC_DM_WG.pdf

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11:55 Foundation Models as a new tool to uncover the dark sector?

Speaker: Joschka Birk (Hamburg University (DE))

2024_05_17_Foundation_Models_for_DM_Benato_Birk_Hallin_Kasieczka.pdf

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12:15 SIFTing for dark shower signals

I present ongoing work seeking to identify the presence of dark shower phenomena in otherwise ordinary-seeming jets using jet substructure techniques with a particular focus on the recently-proposed SIFT algorithm. The aim is to explicitly identify the mass scale signature of the dark shower products which then promptly decay back into SM quarks, giving effectively normal-looking SM jets. This is the most challenging case for detecting dark shower activity; if we can differentiate this from QCD the same tools should be useful to sharpen semi-visible or emerging jet searches as well.

Speaker: William Shepherd

PIONS.pdf

PIONS.pptx

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12:30 Discussion and wrap up

Speakers: Annapaola De Cosa (ETH Zurich (CH)), Suchita Kulkarni (University of Graz), Sukanya Sinha (University of Manchester (GB))

Dark showers discussion session.pdf

Recording

Video preview

13:00 → 13:10 Close out

Speaker: James Frost (University of Oxford (GB))

RoadmapCloseout.pdf