Prospective Sensitivities of Atom Interferometers to Gravitational Waves and Ultralight Dark Matter

Leonardo Badurina, Oliver Buchmueller, John Ellis, Marek Lewicki, Christopher McCabe, Ville Vaskonen

We survey the prospective sensitivities of terrestrial and space-borne atom interferometers (AIs) to gravitational waves (GWs) generated by cosmological and astrophysical sources, and to ultralight dark matter. We discuss the backgrounds from gravitational gradient noise (GGN) in terrestrial detectors, and also binary pulsar and asteroid backgrounds in space-borne detectors. We compare the sensitivities of LIGO and LISA with those of the 100m and 1km stages of the AION terrestrial AI project, as well as two options for the proposed AEDGE AI space mission with cold atom clouds either inside or outside the spacecraft, considering as possible sources the mergers of black holes and neutron stars, supernovae, phase transitions in the early Universe, cosmic strings and quantum fluctuations in the early Universe that could have generated primordial black holes. We also review the capabilities of AION and AEDGE for detecting coherent waves of ultralight scalar dark matter.

Prospects for dark matter detection with inelastic transitions of xenon

Christopher McCabe

Dark matter can scatter and excite a nucleus to a low-lying excitation in a direct detection experiment. This signature is distinct from the canonical elastic scattering signal because the inelastic signal also contains the energy deposited from the subsequent prompt de-excitation of the nucleus. A measurement of the elastic and inelastic signal will allow a single experiment to distinguish between a spin-independent and spin-dependent interaction. For the first time, we characterise the inelastic signal for two-phase xenon detectors in which dark matter inelastically scatters off the Xe-129 or Xe-131 isotope. We do this by implementing a realistic simulation of a typical tonne-scale two-phase xenon detector and by carefully estimating the relevant background signals. With our detector simulation, we explore whether the inelastic signal from the axial-vector interaction is detectable with upcoming tonne-scale detectors. We find that two-phase detectors allow for some discrimination between signal and background so that it is possible to detect dark matter that inelastically scatters off either the Xe-129 or Xe-131 isotope for dark matter particles that are heavier than approximately 100 GeV. If, after two years of data, the XENON1T search for elastic scattering nuclei finds no evidence for dark matter, the possibility of ever detecting an inelastic signal from the axial-vector interaction will be almost entirely excluded.

Inelastic Dark Matter, Non-Standard Halos and the DAMA/LIBRA Results

John March-Russell, Christopher McCabe, Matthew McCullough

The DAMA collaboration have claimed to detect particle dark matter (DM) via an annual modulation in their observed recoil event rate. This appears to be in strong disagreement with the null results of other experiments if interpreted in terms of elastic DM scattering, while agreement for a small region of parameter space is possible for inelastic DM (iDM) due to the altered kinematics of the collision. To date most analyses assume a simple galactic halo DM velocity distribution, the Standard Halo Model, but direct experimental support for the SHM is severely lacking and theoretical studies indicate possible significant differences. We investigate the dependence of DAMA and the other direct detection experiments on the local DM velocity distribution, utilizing the results of the Via Lactea and Dark Disc numerical simulations. We also investigate effects of varying the solar circular velocity, the DM escape velocity, and the DAMA quenching factor within experimental limits. Our data set includes the latest ZEPLIN-III results, as well as full publicly available data sets. Due to the more sensitive dependence of the inelastic cross section on the velocity distribution, we find that with Via Lactea the DAMA results can be consistent with all other experiments over an enlarged region of iDM parameter space, with higher mass particles being preferred, while Dark Disc does not lead to an improvement. A definitive test of DAMA for iDM requires heavy element detectors.

From RATs to riches: mitigating anthropogenic and synanthropic noise in atom interferometer searches for ultra-light dark matter

John Carlton, Christopher McCabe

Atom interferometers offer promising new avenues for detecting ultra-light dark matter (ULDM). The exceptional sensitivity of atom interferometers to fluctuations in the local gravitational potential exposes them to sources of noise from human (anthropogenic) and animal (synanthropic) activity, which may obscure signals from ULDM. We characterise potential anthropogenic and synanthropic noise sources and examine their influence on a year-long measurement campaign by AION-10, an upcoming atom interferometer experiment that will be located at the University of Oxford. We propose a data cleaning framework that identifies and then masks anthropogenic and synanthropic noise. With this framework, we demonstrate that even in noisy conditions, the sensitivity to ULDM can be restored to within between 10% and 40% of an atom shot noise-limited experiment, depending on the specific composition of the anthropogenic and synanthropic noise. This work provides an important step towards creating robust noise reduction analysis strategies in the pursuit of ULDM detection with atom interferometers.

Refined ultralight scalar dark matter searches with compact atom gradiometers

Leonardo Badurina, Diego Blas, Christopher McCabe

Atom interferometry is a powerful experimental technique that can be employed to search for the oscillation of atomic transition energies induced by ultralight scalar dark matter (ULDM). Previous studies have focused on the sensitivity to ULDM of km-length atom gradiometers, where atom interferometers are located at the ends of very long baselines. In this work, we generalize the treatment of the time-dependent signal induced by a linearly-coupled scalar ULDM candidate for vertical atom gradiometers of any length and find correction factors that especially impact the ULDM signal in short-baseline gradiometer configurations. Using these results, we refine the sensitivity estimates in the limit where shot noise dominates for AION-10, a compact 10 m gradiometer that will be operated in Oxford, and discuss optimal experimental parameters that enhance the reach of searches for linearly-coupled scalar ULDM. After comparing the reach of devices operating in broadband and resonant modes, we show that well-designed compact atom gradiometers are able to explore regions of dark matter parameter space that are not yet constrained.

Extended gamma-ray emission from Coy Dark Matter

Celine Boehm, Matthew J. Dolan, Christopher McCabe, Michael Spannowsky, Chris J. Wallace

We show that it is possible for WIMP dark matter to produce a large signal in indirect dark matter searches without producing signals elsewhere. We illustrate our point by fitting the Fermi-LAT extended galactic gamma-ray excess with a simple model of Dirac dark matter that annihilates primarily into b quarks via a pseudoscalar. Current collider constraints are weak while the 14 TeV LHC run will constrain a limited portion of the parameter space. No signal is expected in additional indirect searches or at future direct detection experiments. Our results emphasise the importance of fully understanding potential indirect signals of dark matter as they may provide the only information about the dark matter particle.

Characterising dark matter searches at colliders and direct detection experiments: Vector mediators

Oliver Buchmueller, Matthew J. Dolan, Sarah A. Malik, Christopher McCabe

We introduce a Minimal Simplified Dark Matter (MSDM) framework to quantitatively characterise dark matter (DM) searches at the LHC. We study two MSDM models where the DM is a Dirac fermion which interacts with a vector and axial-vector mediator. The models are characterised by four parameters: the DM and mediator masses, and the mediator couplings to DM and quarks. The MSDM models accurately capture the full event kinematics, and the dependence on all masses and couplings can be systematically studied. The interpretation of mono-jet searches in this framework can be used to establish an equal-footing comparison with direct detection experiments. For theories with a vector mediator, LHC mono-jet searches possess better sensitivity than direct detection searches for light DM masses (less than 5 GeV). For axial-vector mediators, LHC and direct detection searches generally probe orthogonal directions in the parameter space. We explore the projected limits of these searches from the ultimate reach of the LHC and multi-ton xenon direct detection experiments, and find that the complementarity of the searches remains. Finally, we provide a comparison of limits in the MSDM and effective field theory (EFT) frameworks to highlight the deficiencies of the EFT framework, particularly when exploring the complementarity of mono-jet and direct detection searches.

Interplay and Characterization of Dark Matter Searches at Colliders and in Direct Detection Experiments

Sarah A. Malik, Christopher McCabe, Henrique Araujo, Alexander Belyaev, Celine Boehm, Jim Brooke, Oliver Buchmueller, Gavin Davies, Albert De Roeck, Kees de Vries, Matthew J. Dolan, John Ellis, Malcolm Fairbairn, Henning Flaecher, Loukas Gouskos, Valentin V. Khoze, Greg Landsberg, Dave Newbold, Michele Papucci, Timothy Sumner, Marc Thomas, Steven Worm

In this White Paper we present and discuss a concrete proposal for the consistent interpretation of Dark Matter searches at colliders and in direct detection experiments. Based on a specific implementation of simplified models of vector and axial-vector mediator exchanges, this proposal demonstrates how the two search strategies can be compared on an equal footing.

Supernova neutrino physics with xenon dark matter detectors: A timely perspective

Rafael F. Lang, Christopher McCabe, Shayne Reichard, Marco Selvi, Irene Tamborra

Dark matter detectors that utilize liquid xenon have now achieved tonne-scale targets, giving them sensitivity to all flavours of supernova neutrinos via coherent elastic neutrino-nucleus scattering. Considering for the first time a realistic detector model, we simulate the expected supernova neutrino signal for different progenitor masses and nuclear equations of state in existing and upcoming dual-phase liquid xenon experiments. We show that the proportional scintillation signal (S2) of a dual-phase detector allows for a clear observation of the neutrino signal and guarantees a particularly low energy threshold, while the backgrounds are rendered negligible during the supernova burst. XENON1T (XENONnT and LZ; DARWIN) experiments will be sensitive to a supernova burst up to 25 (35; 65) kpc from Earth at a significance of more than 5 sigma, observing approximately 35 (123; 704) events from a 27 Msun supernova progenitor at 10 kpc. Moreover, it will be possible to measure the average neutrino energy of all flavours, to constrain the total explosion energy, and to reconstruct the supernova neutrino light curve. Our results suggest that a large xenon detector such as DARWIN will be competitive with dedicated neutrino telescopes, while providing complementary information that is not otherwise accessible.

Directly detecting sub-GeV dark matter with electrons from nuclear scattering

Matthew J. Dolan, Felix Kahlhoefer, Christopher McCabe

Dark matter (DM) particles with mass in the sub-GeV range are an attractive alternative to heavier weakly-interacting massive particles, but direct detection of such light particles is challenging. If however DM-nucleus scattering leads to ionisation of the recoiling atom, the resulting electron may be detected even if the nuclear recoil is unobservable. We demonstrate that including this effect significantly enhances direct detection sensitivity to sub-GeV DM. Existing experiments set world-leading limits, and future experiments may probe the cross sections relevant for thermal freeze-out.

Searching for screened scalar forces with long-baseline atom interferometers

Hannah Banks, John Carlton, Benjamin Elder, Thomas Hird, Christopher McCabe

Screened scalars are ubiquitous in many dark-sector models. They give rise to non-trivial fifth forces whilst evading experimental constraints through density-dependent screening mechanisms. We propose equipping a 10\,m-scale long-baseline atom interferometer with an annular planar source mass inside the vacuum chamber to search for such screened fifth forces. Two key challenges arise: distinguishing the static fifth force from backgrounds, and isolating it from the plate's Newtonian gravity. We introduce the `$Q$-flip protocol', which alternates between interferometry sequences to induce controllable time-dependence, aiding signal extraction and de-trending of transient noise. We further develop an \emph{in situ} calibration procedure to characterise the plate's Newtonian gravity and reach shot-noise-limited sensitivity. We show that our proposal could test theoretically motivated parameter space, advancing existing bounds in chameleon and symmetron screened scalar models by $1$ to $1.5$ orders of magnitude. Our proposal is directly applicable to forthcoming experiments, such as AION-10 or VLBAI, and is readily extensible to broader theoretical models and longer baselines.

A taste of dark matter: Flavour constraints on pseudoscalar mediators

Matthew J. Dolan, Felix Kahlhoefer, Christopher McCabe, Kai Schmidt-Hoberg

Dark matter interacting via the exchange of a light pseudoscalar can induce observable signals in indirect detection experiments and experience large self-interactions while evading the strong bounds from direct dark matter searches. The pseudoscalar mediator will however induce flavour-changing interactions in the Standard Model, providing a promising alternative way to test these models. We investigate in detail the constraints arising from rare meson decays and fixed target experiments for different coupling structures between the pseudoscalar and Standard Model fermions. The resulting bounds are highly complementary to the information inferred from the dark matter relic density and the constraints from primordial nucleosynthesis. We discuss the implications of our findings for the dark matter self-interaction cross section and the prospects of probing dark matter coupled to a light pseudoscalar with direct or indirect detection experiments. In particular, we find that a pseudoscalar mediator can only explain the Galactic Centre excess if its mass is above that of the B mesons, and that it is impossible to obtain a sufficiently large direct detection cross section to account for the DAMA modulation

Listening for ultra-heavy dark matter with underwater acoustic detectors

Damon Cleaver, Christopher McCabe, Ciaran A. J. O'Hare

Ultra-heavy dark matter candidates evade traditional direct detection experiments due to their low particle flux. We explore the potential of large underwater acoustic arrays, originally developed for ultra-high energy neutrino detection, to detect ultra-heavy dark matter interactions. These particles deposit energy via nuclear scattering while traversing seawater, generating thermo-acoustic waves detectable by hydrophones. We present the first robust first-principles calculation of dark matter-induced acoustic waves, establishing a theoretical framework for signal modelling and sensitivity estimates. Our framework incorporates frequency-dependent attenuation effects, including viscous and chemical relaxation, not considered in previous calculations. A sensitivity analysis for a hypothetical 100 cubic kilometre hydrophone array in the Mediterranean Sea demonstrates that such an array could extend sensitivity to the previously unexplored mass range of $0.1$-$10\,μ\mathrm{g}$ ($\sim10^{20}$-$10^{23}\,\mathrm{GeV}$), with sensitivity to both spin-independent and spin-dependent interactions. Our results establish acoustic detection as a complementary dark matter search method, enabling searches in existing hydrophone data and informing future detector designs.

Letter of Intent: AICE -- 100m Atom Interferometer Experiment at CERN

Charles Baynham, Andrea Bertoldi, Diego Blas, Oliver Buchmueller, Sergio Calatroni, Vassilis Charmandaris, Maria Luisa Chiofalo, Pierre Cladé, Jonathon Coleman, Fabio Di Pumpo, John Ellis, Naceur Gaaloul, Saïda Guellati-Khelifa, Tiffany Harte, Richard Hobson, Michael Holynski, Samuel Lellouch, Lucas Lombriser, Elias Lopez Asamar, Michele Maggiore, Christopher McCabe, Jeremiah Mitchell, Ernst M. Rasel, Federico Sanchez Nieto, Wolfgang Schleich, Dennis Schlippert, Ulrich Schneider, Steven Schramm, Marcelle Soares-Santos, Guglielmo M. Tino, Jonathan N. Tinsley, Tristan Valenzuela, Maurits van der Grinten, Wolf von Klitzing

We propose an O(100)m Atom Interferometer (AI) experiment -- AICE -- to be installed against a wall of the PX46 access shaft to the LHC. This experiment would probe unexplored ranges of the possible couplings of bosonic ultralight dark matter (ULDM) to atomic constituents and undertake a pioneering search for gravitational waves (GWs) at frequencies intermediate between those to which existing and planned experiments are sensitive, among other fundamental physics studies. A conceptual feasibility study showed that this AI experiment could be isolated from the LHC by installing a shielding wall in the TX46 gallery, and surveyed issues related to the proximity of the LHC machine, finding no technical obstacles. A detailed technical implementation study has shown that the preparatory civil-engineering work, installation of bespoke radiation shielding, deployment of access-control systems and safety alarms, and installation of an elevator platform could be carried out during LS3, allowing installation and operation of the AICE detector to proceed during Run 4 without impacting HL-LHC operation. These studies have established that PX46 is a uniquely promising location for an AI experiment. We foresee that, if the CERN management encourages this Letter of Intent, a significant fraction of the Terrestrial Very Long Baseline Atom Interferometer (TVLBAI) Proto-Collaboration may wish to contribute to AICE.

SHM$^{++}$: A Refinement of the Standard Halo Model for Dark Matter Searches in Light of the Gaia Sausage

N. Wyn Evans, Ciaran A. J. O'Hare, Christopher McCabe

Predicting signals in experiments to directly detect dark matter (DM) requires a form for the local DM velocity distribution. Hitherto, the standard halo model (SHM), in which velocities are isotropic and follow a truncated Gaussian law, has performed this job. New data, however, suggest that a substantial fraction of our stellar halo lies in a strongly radially anisotropic population, the 'Gaia Sausage'. Inspired by this recent discovery, we introduce an updated DM halo model, the SHM$^{++}$, which includes a `Sausage' component, thus better describing the known features of our galaxy. The SHM$^{++}$ is a simple analytic model with five parameters: the circular speed, local escape speed and local DM density, which we update to be consistent with the latest data, and two new parameters: the anisotropy and the density of DM in the Sausage. The impact of the SHM$^{++}$ on signal models for WIMPs and axions is rather modest since the multiple changes and updates have competing effects. The largest change occurs for directional detectors which have sensitivity to the full three-dimensional velocity distribution.

A Tale of Tails: Dark Matter Interpretations of the Fermi GeV Excess in Light of Background Model Systematics

Francesca Calore, Ilias Cholis, Christopher McCabe, Christoph Weniger

Several groups have identified an extended excess of gamma rays over the modeled foreground and background emissions towards the Galactic center (GC) based on observations with the Fermi Large Area Telescope. This excess emission is compatible in morphology and spectrum with a telltale sign from dark matter (DM) annihilation. Here, we present a critical reassessment of DM interpretations of the GC signal in light of the foreground and background uncertainties that some of us recently outlaid in Calore et al. 2014. We find that a much larger number of DM models fits the gamma-ray data than previously noted. In particular: (1) In the case of DM annihilation into $\bar{b}b$, we find that even large DM masses up to $m_χ\simeq$ 74 GeV are allowed with a $p$-value $> 0.05$. (2) Surprisingly, annihilation into non-relativistic hh gives a good fit to the data. (3) The inverse Compton emission from $μ^+μ^-$ with $m_χ\sim$ 60-70 GeV can also account for the excess at higher latitudes, $|b|>2^\circ$, both in its spectrum and morphology. We also present novel constraints on a large number of mixed annihilation channels, including cascade annihilation involving hidden sector mediators. Finally, we show that the current limits from dwarf spheroidal observations are not in tension with a DM interpretation when uncertainties on the DM halo profile are accounted for.

Cold Atoms in Space: Community Workshop Summary and Proposed Road-Map

Ivan Alonso, Cristiano Alpigiani, Brett Altschul, Henrique Araujo, Gianluigi Arduini, Jan Arlt, Leonardo Badurina, Antun Balaz, Satvika Bandarupally, Barry C Barish Michele Barone, Michele Barsanti, Steven Bass, Angelo Bassi, Baptiste Battelier, Charles F. A. Baynham, Quentin Beaufils, Aleksandar Belic, Joel Berge, Jose Bernabeu, Andrea Bertoldi, Robert Bingham, Sebastien Bize, Diego Blas, Kai Bongs, Philippe Bouyer, Carla Braitenberg, Christian Brand, Claus Braxmaier, Alexandre Bresson, Oliver Buchmueller, Dmitry Budker, Luıs Bugalho, Sergey Burdin, Luigi Cacciapuoti Simone Callegari, Xavier Calmet, Davide Calonico, Benjamin Canuel, Laurentiu-Ioan Caramete, Olivier Carraz, Donatella Cassettari, Pratik Chakraborty, Swapan Chattopadhyay, Upasna Chauhan, Xuzong Chen, Yu-Ao Chen, Maria Luisa Chiofalo, Jonathon Coleman, Robin Corgier, J. P. Cotter, A. Michael Cruise, Yanou Cui, Gavin Davies, Albert De Roeck, Marcel Demarteau, Andrei Derevianko, Marco Di Clemente, Goran S. Djordjevic, Sandro Donadi, Olivier Dore, Peter Dornan, Michael Doser, Giannis Drougakis, Jacob Dunningham, Sajan Easo, Joshua Eby, Gedminas Elertas, John Ellis, David Evans, Pandora Examilioti, Pavel Fadeev, Mattia Fanı, Farida Fassi, Marco Fattori, Michael A. Fedderke, Daniel Felea, Chen-Hao Feng, Jorge Ferreras, Robert Flack, Victor V. Flambaum, Rene Forsberg, Mark Fromhold, Naceur Gaaloul, Barry M. Garraway, Maria Georgousi, Andrew Geraci, Kurt Gibble, Valerie Gibson, Patrick Gill, Gian F. Giudice, Jon Goldwin, Oliver Gould, Oleg Grachov, Peter W. Graham, Dario Grasso, Paul F. Griffin, Christine Guerlin, Mustafa Gundogan, Ratnesh K Gupta, Martin Haehnelt, Ekim T. Hanımeli, Leonie Hawkins, Aurelien Hees, Victoria A. Henderson, Waldemar Herr, Sven Herrmann, Thomas Hird, Richard Hobson, Vincent Hock, Jason M. Hogan, Bodil Holst, Michael Holynski, Ulf Israelsson, Peter Jeglic, Philippe Jetzer, Gediminas Juzeliunas, Rainer Kaltenbaek, Jernej F. Kamenik, Alex Kehagias, Teodora Kirova, Marton Kiss-Toth, Sebastian Koke, Shimon Kolkowitz, Georgy Kornakov, Tim Kovachy, Markus Krutzik, Mukesh Kumar, Pradeep Kumar, Claus Lammerzahl, Greg Landsberg, Christophe Le Poncin-Lafitte, David R. Leibrandt, Thomas Leveque, Marek Lewicki, Rui Li, Anna Lipniacka, Christian Lisdat Mia Liu, J. L. Lopez-Gonzalez, Sina Loriani, Jorma Louko, Giuseppe Gaetano Luciano, Nathan Lundblad, Steve Maddox, M. A. Mahmoud, Azadeh Maleknejad, John March-Russell, Didier Massonnet, Christopher McCabe, Matthias Meister, Tadej Meznarsic, Salvatore Micalizio, Federica Migliaccio, Peter Millington, Milan Milosevic, Jeremiah Mitchell, Gavin W. Morley, Jurgen Muller, Eamonn Murphy, Ozgur E. Mustecaplıoglu, Val OShea, Daniel K. L. Oi, Judith Olson, Debapriya Pal, Dimitris G. Papazoglou, Elizabeth Pasatembou, Mauro Paternostro, Krzysztof Pawlowski, Emanuele Pelucchi, Franck Pereira dos Santos, Achim Peters, Igor Pikovski, Apostolos Pilaftsis, Alexandra Pinto, Marco Prevedelli, Vishnupriya Puthiya-Veettil, John Quenby, Johann Rafelski, Ernst M. Rasel, Cornelis Ravensbergen, Mirko Reguzzoni, Andrea Richaud, Isabelle Riou, Markus Rothacher, Albert Roura, Andreas Ruschhaupt, Dylan O. Sabulsky, Marianna Safronova, Ippocratis D. Saltas, Leonardo Salvi, Muhammed Sameed, Pandey Saurabh, Stefan Schaffer, Stephan Schiller, Manuel Schilling, Vladimir Schkolnik, Dennis Schlippert, Piet O. Schmidt, Harald Schnatz, Jean Schneider, Ulrich Schneider, Florian Schreck, Christian Schubert, Armin Shayeghi, Nathaniel Sherrill, Ian Shipsey, Carla Signorini, Rajeev Singh, Yeshpal Singh, Constantinos Skordis, Augusto Smerzi, Carlos F. Sopuerta, Fiodor Sorrentino, Paraskevas Sphicas, Yevgeny V. Stadnik, Petruta Stefanescu, Marco G. Tarallo, Silvia Tentindo, Guglielmo M. Tino, Jonathan N. Tinsley, Vincenza Tornatore, Philipp Treutlein, Andrea Trombettoni, Yu-Dai Tsai, Philip Tuckey, Melissa A Uchida, Tristan Valenzuela, Mathias Van Den Bossche, Ville Vaskonen, Gunjan Verma, Flavio Vetrano, Christian Vogt, Wolf von Klitzing, Pierre Waller, Reinhold Walser, Eric Wille Jason Williams, Patrick Windpassinger, Ulric Wittrock, Peter Wolf, Marian Woltmann, Lisa Worner, Andre Xuereb, Mohamed Yahia, Efe Yazgan, Nan Yu, Nassim Zahzam, Emmanuel Zambrini Cruzeiro, Mingsheng Zhan, Xinhao Zou, Jure Zupan, Erik Zupanic

Beyond Effective Field Theory for Dark Matter Searches at the LHC

O. Buchmueller, Matthew J. Dolan, Christopher McCabe

We study the validity of effective field theory (EFT) interpretations of monojet searches for dark matter at the LHC for vector and axial-vector interactions. We show that the EFT approach is valid when the mediator has mass m_med greater than 2.5 TeV. We find that the current limits on the contact interaction scale Lambda in the EFT apply to theories that are perturbative for dark matter mass m_DM < 800 GeV. However, for all values of m_DM in these theories, the mediator width is larger than the mass, so that a particle-like interpretation of the mediator is doubtful. Furthermore, consistency with the thermal relic density occurs only for 170 <m_DM < 520 GeV. For lighter mediator masses, the EFT limit either under-estimates the true limit (because the process is resonantly enhanced) or over-estimates it (because the missing energy distribution is too soft). We give some `rules of thumb' that can be used to estimate the limit on Lambda (to an accuracy of about 50%) for any dark matter and mediator masses from knowledge of the EFT limit. We also compare the relative sensitivities of monojet and dark matter direct detection searches finding that both dominate in different regions of the m_DM-m_med plane. Comparing only the EFT limit with direct searches is misleading and can lead to incorrect conclusions about the relative sensitivity of the two search approaches.

Terrestrial Very-Long-Baseline Atom Interferometry: Summary of the Second Workshop

Adam Abdalla, Mahiro Abe, Sven Abend, Mouine Abidi, Monika Aidelsburger, Ashkan Alibabaei, Baptiste Allard, John Antoniadis, Gianluigi Arduini, Nadja Augst, Philippos Balamatsias, Antun Balaz, Hannah Banks, Rachel L. Barcklay, Michele Barone, Michele Barsanti, Mark G. Bason, Angelo Bassi, Jean-Baptiste Bayle, Charles F. A. Baynham, Quentin Beaufils, Slyan Beldjoudi, Aleksandar Belic, Shayne Bennetts, Jose Bernabeu, Andrea Bertoldi, Clara Bigard, N. P. Bigelow, Robert Bingham, Diego Blas, Alexey Bobrick, Samuel Boehringer, Aleksandar Bogojevic, Kai Bongs, Daniela Bortoletto, Philippe Bouyer, Christian Brand, Oliver Buchmueller, Gabriela Buica, Sergio Calatroni, Lo Calmels, Priscilla Canizares, Benjamin Canuel, Ana Caramete, Laurentiu-Ioan Caramete, Matteo Carlesso, John Carlton, Samuel P. Carman, Andrew Carroll, Mateo Casariego, Minoas Chairetis, Vassilis Charmandaris, Upasna Chauhan, Jiajun Chen, Maria Luisa, Chiofalo, Donatella Ciampini, Alessia Cimbri, Pierre Clad, Jonathon Coleman, Florin Lucian Constantin, Carlo R. Contaldi, Robin Corgier, Bineet Dash, G. J. Davies, Claudia de Rham, Albert De Roeck, Daniel Derr, Soumyodeep Dey, Fabio Di Pumpo, Goran S. Djordjevic, Babette Doebrich, Peter Dornan, Michael Doser, Giannis Drougakis, Jacob Dunningham, Alisher Duspayev, Sajan Easo, Joshua Eby, Maxim Efremov, Gedminas Elertas, John Ellis, Nicholas Entin, Stephen Fairhurst, Mattia Fani, Farida Fassi, Pierre Fayet, Daniel Felea, Jie Feng, Robert Flack, Chris Foot, Tim Freegarde, Elina Fuchs, Naceur Gaaloul, Dongfeng Gao, Susan Gardner, Barry M. Garraway, Carlos L. Garrido Alzar, Alexandre Gauguet, Enno Giese, Patrick Gill, Gian F. Giudice, Eric P. Glasbrenner, Jonah Glick, Peter W. Graham, Eduardo Granados, Paul F. Griffin, Jordan Gue, Saida Guellati-Khelifa, Subhadeep Gupta, Vishu Gupta, Lucia Hackermueller, Martin Haehnelt, Timo Hakulinen, Klemens Hammerer, Ekim T. Hanimeli, Tiffany Harte, Sabrina Hartmann, Leonie Hawkins, Aurelien Hees, Alexander Herbst, Thomas M. Hird, Richard Hobson, Jason Hogan, Bodil Holst, Michael Holynski, Onur Hosten, Chung Chuan Hsu, Wayne Cheng-Wei Huang, Kenneth M. Hughes, Kamran Hussain, Gert Huetsi, Antonio Iovino, Maria-Catalina Isfan, Gregor Janson, Peter Jeglic, Philippe Jetzer, Yijun Jiang, Gediminas Juzeliunas, Wilhelm Kaenders, Matti Kalliokoski, Alex Kehagias, Eva Kilian, Carsten Klempt, Peter Knight, Soumen Koley, Bernd Konrad, Tim Kovachy, Markus Krutzik, Mukesh Kumar, Pradeep Kumar, Hamza Labiad, Shau-Yu Lan, Arnaud Landragin, Greg Landsberg, Mehdi Langlois, Bryony Lanigan, Christophe Le Poncin-Lafitte, Samuel Lellouch, Bruno Leone, Marek Lewicki, Yu-Hung Lien, Lucas Lombriser, Elias Lopez Asamar, J. Luis Lopez-Gonzalez, Adam Lowe, Chen Lu, Giuseppe Gaetano Luciano, Nathan Lundblad, Cristian de J. Lpez Monjaraz, Maena Mackoit-Sinkeviien, Michele Maggiore, Anirban Majumdar, Konstantinos Makris, Azadeh Maleknejad, Anna L. Marchant, Agnese Mariotti, Christos Markou, Barnaby Matthews, Anupam Mazumdar, Christopher McCabe, Matthias Meister, Giorgio Mentasti, Jonathan Menu, Giuseppe Messineo, Bernd Meyer-Hoppe, Salvatore Micalizio, Federica Migliaccio, Peter Millington, Milan Milosevic, Abhay Mishra, Jeremiah Mitchell, Gavin W. Morley, Noam Mouelle, Juergen Mueller, David Newbold, Wei-Tou Ni, Christian Niehof, Johannes Noller, Senad Odzak, Daniel K. L. Oi, Andreas Oikonomou, Yasser Omar, Chris Overstreet, Julia Pahl, Sean Paling, Zhongyin Pan, George Pappas, Vinay Pareek, Elizabeth Pasatembou, Mauro Paternostro, Vishal K. Pathak, Emanuele Pelucchi, Franck Pereira dos Santos, Achim Peters, Annie Pichery, Igor Pikovski, Apostolos Pilaftsis, Florentina-Crenguta Pislan, Robert Plunkett, Rosa Poggiani, Marco Prevedelli, Vishnupriya Puthiya Veettil, Johann Rafelski, Juhan Raidal, Martti Raidal, Ernst Maria Rasel, Sebastien Renaux-Petel, Andrea Richaud, Pedro Rivero-Antunez, Tangui Rodzinka, Albert Roura, Jan Rudolph, Dylan Sabulsky, Marianna S. Safronova, Mairi Sakellariadou, Leonardo Salvi, Muhammed Sameed, Sumit Sarkar, Patrik Schach, Stefan Alaric Schaeffer, Jesse Schelfhout, Manuel Schilling, Vladimir Schkolnik, Wolfgang P. Schleich, Dennis Schlippert, Ulrich Schneider, Florian Schreck, Ariel Schwartzman, Nico Schwersenz, Olga Sergijenko, Haifa Rejeb Sfar, Lijing Shao, Ian Shipsey, Jing Shu, Yeshpal Singh, Carlos F. Sopuerta, Marianna Sorba, Fiodor Sorrentino, Alessandro D. A. M Spallicci, Petruta Stefanescu, Nikolaos Stergioulas, Daniel Stoerk, Jannik Stroehle, Hrudya Thaivalappil Sunilkumar, Zoie Tam, Dhruv Tandon, Yijun Tang, Dorothee Tell, Jacques Tempere, Dylan J. Temples, Rohit P Thampy, Ingmari C. Tietje, Guglielmo M. Tino, Jonathan N. Tinsley, Ovidiu Tintareanu Mircea, Kimberly Tkalec, Andrew J. Tolley, Vincenza Tornatore, Alejandro Torres-Orjuela, Philipp Treutlein, Andrea Trombettoni, Christian Ufrecht, Juan Urrutia, Tristan Valenzuela, Linda R. Valerio, Maurits van der Grinten, Ville Vaskonen, Veronica Vazquez-Aceves, Hardi Veermae, Flavio Vetrano, Nikolay V. Vitanov, Wolf von Klitzing, Sebastian Wald, Thomas Walker, Reinhold Walser, Jin Wang, Yan Wang, C. A. Weidner, Andr Wenzlawski, Michael Werner, Lisa Woerner, Mohamed E. Yahia, Efe Yazgan, Emmanuel Zambrini Cruzeiro, M. Zarei, Mingsheng Zhan, Shengnan Zhang, Lin Zhou, Erik Zupanic

Long-Baseline Atom Interferometry

Antun Balaz, Diego Blas, Oliver Buchmueller, Sergio Calatroni, Laurentiu-Ioan Caramete, David Cerdeno, Maria Luisa Chiofalo, Fabio Di Pumpo, Goran Djordjevic, John Ellis, Pierre Fayet, Chris Foot, Naceur Gaaloul, Susan Gardner, Barry M Garraway, Alexandre Gauguet, Enno Giese, Jason M. Hogan, Onur Hosten, Alex Kehagias, Eva Kilian, Tim Kovachy, Carlos Lacasta, Marek Lewicki, Elias Lopez Asamar, J. Luis Lopez-Gonzalez, Nathan Lundblad, Michele Maggiore, Christopher McCabe, John McFerran, Gaetano Mileti, Peter Millington, Gavin W. Morley, Senad Odzak, Chris Overstreet, Krzysztof Pawlowski, Emanuele Pelucchi, Johann Rafelski, Albert Roura, Marianna S. Safronova, Florian Schreck, Olga Sergijenko, Yeshpal Singh, Marcelle Soares-Santos, Nikolaos Stergioulas, Guglielmo M. Tino, J. N. Tinsley, Hendrik Ulbricht, Maurits van der Grinten, Ville Vaskonen, Wolf von Klitzing, Andre Xuereb, Emmanuel Zambrini Cruzeiro

Long-baseline atom interferometry is a promising technique for probing various aspects of fundamental physics, astrophysics and cosmology, including searches for ultralight dark matter (ULDM) and for gravitational waves (GWs) in the frequency range around 1~Hz that is not covered by present and planned detectors using laser interferometry. The MAGIS detector is under construction at Fermilab, as is the MIGA detector in France. The PX46 access shaft to the LHC has been identified as a very suitable site for an atom interferometer of height $\sim 100$m, sites at the Boulby mine in the UK and the Canfranc Laboratory are also under investigation, and possible sites for km-class detectors have been suggested. The Terrestrial Very-Long-Baseline Atom Interferometry (TVLBAI) Proto-Collaboration proposes a coordinated programme of interferometers of increasing baselines.