Wed·Oct 7, 2020Wednesday·October 7, 2020

1. 01*

   Searching for QCD Instantons at Hadron Colliders

   Valentin V. Khoze🇬🇧 · Daniel L. Milne🇬🇧 · Michael Spannowsky🇬🇧

   QCD instantons are arguably the best motivated yet unobserved nonperturbative effects predicted by the Standard Model. A discovery and detailed study of instanton-generated processes at colliders would provide a new window into the phenomenological exploration of QCD and a vastly improved fundamental understanding of its non-perturbative dynamics. Building on the optical theorem, we numerically calculate the total instanton cross-section from the elastic scattering amplitude, also including quantum effects arising from resummed perturbative exchanges between hard gluons in the initial state, thereby improving in accuracy on previous results. Although QCD instanton processes are predicted to be produced with a large scattering cross-section at small centre-of-mass partonic energies, discovering them at hadron colliders is a challenging task that requires dedicated search strategies. We evaluate the sensitivity of high-luminosity LHC runs, as well as low-luminosity LHC and Tevatron runs. We find that LHC low-luminosity runs in particular, which do not suffer from large pileup and trigger thresholds, show a very good sensitivity for discovering QCD instanton-generated processes.

   hep-phhep-exhep-thPRD(2021)·17 citations
2. 02*

   $|\Delta \mathcal{B}|=2$: A State of the Field, and Looking Forward--A brief status report of theoretical and experimental physics opportunities

   Kaladi Babu · Joshua Barrow · Zurab Berezhiani · Leah Broussard · Marcel Demarteau · Bhupal Dev · Jordy de Vries · Alexey Fomin · Susan Gardner · Sudhakantha Girmohanta · Julian Heeck · Yuri Kamyshkov and 12 other authors

   The origin of the matter-antimatter asymmetry apparently obligates the laws of physics to include some mechanism of baryon number ($\mathcal{B}$) violation. Searches for interactions violating $\mathcal{B}$ and baryon-minus-lepton number $(\mathcal{B}-\mathcal{L})$ represent a rich and underutilized opportunity. These are complementary to the existing, broad program of searches for $\mathcal{L}$-violating modes such as neutrinoless double $\beta$-decay which could provide deeper understandings of the plausibility of leptogenesis, or $\mathcal{B}$-violating, $(\mathcal{B}-\mathcal{L})$-conserving processes such as proton decay. In particular, a low-scale, post-sphaleron violation mechanism of $(\mathcal{B}-\mathcal{L})$ could provide a \textit{testable} form of baryogenesis. Though theoretically compelling, searches for such $(\mathcal{B}-\mathcal{L})$-violating processes like $\Delta \mathcal{B}=2$ dinucleon decay and $n\to \bar{n}$ remain relatively underexplored experimentally compared to other rare processes. By taking advantage of upcoming facilities such as the Deep Underground Neutrino Experiment and the European Spallation Source, this gap can be addressed with new intranuclear and free searches for neutron transformations with very high sensitivity, perhaps greater than three orders of magnitude higher than previous experimental searches. This proceedings reports on recent theoretical and experimental advances and sensitivities of next-generation searches for neutron transformations were detailed as part of the Amherst Center for Fundamental Interactions Workshop, "Theoretical Innovations for Future Experiments Regarding Baryon Number Violation," directly coordinated with the Rare Processes and Precision Measurements Frontier.

   hep-phhep-exhep-thnucl-th21 citations
3. 03*

   Axion-Polaritons in the Magnetic Dual Chiral Density Wave Phase of Dense QCD

   Efrain J. Ferrer🇺🇸 · Vivian de la Incera🇺🇸

   We investigate the propagation of electromagnetic radiation in the magnetic dual chiral density wave (MDCDW) phase of dense quark matter. Considering the theory of low-energy fluctuations in this phase, we show how linearly polarized photons reaching the MDCDW medium couple to the fluctuation field to produce two hybridized modes of propagation that we call in analogy with similar phenomenon in condensed matter physics axion polaritons, one of them being gapless and the other gapped. The gapped mode's gap is proportional to the background magnetic field and inversely proportional to the amplitude of the inhomogeneous condensate. The generation of axion polaritons can be traced back to the presence of the chiral anomaly in the low-energy theory of the fluctuations. Considering the Primakoff effect in the MDCDW medium, we argued that axion polaritons can be generated inside quark stars bombarded by energetic photons coming from gamma-ray bursts and point out that this mechanism could serve to explain the missing pulsar paradox in the galaxy center.

   hep-phastro-ph.HEnucl-thNPB(2023)·12 citations
4. 04*

   Explaining muon $g-2$ anomaly in a non-universal $U(1{)}_X$ extended SUSY theory

   J. S. Alvarado🇨🇴 · M. A. Bulla🇨🇴 · D. G. Martinez🇺🇸 · R. Martinez🇨🇴

   A non-universal $U(1{)}_X$ extension to the Standard Model composed of two scalar doublets and two scalar singlets together with three additional quark singlets and two lepton singlets and three generations of right-handed and Majorana neutrinos is made to explain lepton mass hierarchy, neutrino masses via inverse seesaw mechanism and muon anomalous magnetic moment in an anomaly free framework. In the present model, exotic and Standard Model particles acquire mass thanks to vacuum expectation values at different scales, yet the electron and the lightest neutrino are tree level massless but massive at one-loop level. By considering a numerical exploration and under the constraint of the Higgs mass, neutrino mass differences and PMNS matrix, it is found that only contributions due to exotic neutrinos interacting with charged scalars are relevant to muon $g-2$, though they are negative. Thus, the SUSY extension is considered and it is found that muon $g-2$ can be explained by allowing $U(1{)}_X$ vacuum expectation values to lie in the TeV scale thanks to SUSY soft-breaking interactions for at least $\sim 10^5$ GeV masses. Thus, the contribution due to exotic neutrinos interacting with $W$ gauge bosons is positive and no longer negligible which added to all other contributions might explain the anomaly.

   hep-ph2 citations
5. 05*

   Bubble wall velocity: heavy physics effects

   Aleksandr Azatov🇮🇹 · Miguel Vanvlasselaer🇮🇹

   We analyse the dynamics of the relativistic bubble expansion during the first order phase transition focusing on the ultra relativistic velocities $\gamma \gg 1$. We show that fields much heavier than the scale of the phase transition can significantly contribute to the friction and modify the motion of the bubble wall leading to interesting phenomenological consequences. NLO effects on the friction due to the soft vector field emission are reviewed as well.

   hep-phJCAP(2021)·165 citations
6. 06*

   Obscure Higgs boson at Colliders

   Priyotosh Bandyopadhyay🇮🇳 · Antonio Costantini🇮🇹

   In this study we consider an extension of the Standard Model with a complex hypercharge zero triplet scalar. In this scenario one of the charged Higgs bosons remains purely triplet and does not couple to the fermions, making it elusive at colliders. Also the physical pseudoscalar is a pure triplet and this purity makes it a suitable dark matter candidate without the need of discrete symmetries, unlike other extensions. The bounds from relic density and direct dark matter search experiments select its mass to be $\sim 1.35-1.60$ TeV. The pure triplet charged Higgs gives rise to displaced signatures and their sensitivity at LHC and MATHUSLA have been studied. The prospects at present and future hadron/muon colliders of such exotic scalars are pointed out by calculating their productions cross-section and dominant decay modes. We present also the expected reach for the triplet states at a multi-TeV muon collider.

   hep-phPRD(2021)·63 citations
7. 07*

   Hadronic Resonance Gas Model and Multiplicity Dependence in p-p, p-Pb, Pb-Pb collisions: Strangeness Enhancement

   Jean Cleymans🇿🇦 · Pok Man Lo🇵🇱 · Krzysztof Redlich🇵🇱 · Natasha Sharma🇮🇳

   Recently the ALICE collaboration has observed an interesting systematic behaviour of ratios of identified particles to pions yields at the LHC, showing that they depend solely on the charged-particle multiplicity in pp, pPb and PbPb collisions. In particular, the yields of (multi)strange particles relative to pions, increases with multiplicity and the enhancement is mode pronounced with increasing strangeness content. We will argue, that such a pattern of arises naturally in the thermal model taking into account exact strangeness conservation. Furthermore, extending the thermal model by including hadron interactions within the S-matrix approach, the ALICE data can be well quantified by the thermal particle yields at the chiral-crossover temperature, as previously found in central Pb-Pb collisions.

   hep-phActa Phys.Polon.Supp.(2021)·2 citations
8. 08*

   Towards establishing the second $b$-flavored CKM unitarity triangle

   Zhi-zhong Xing🇨🇳 · Di Zhang🇨🇳

   Some fine differences between the twin $b$-flavored unitarity triangles are calculated by means of a generalized Wolfenstein parametrization of the CKM matrix, and a possibility of experimentally establishing the second triangle is briefly discussed. We find that the apexes of these two triangles, characterized respectively by $(\overline{\rho },\overline{\eta })$ and $(\tilde{\rho },\tilde{\eta })$, are located on the same circular arc in the complex plane. This observation provides us with a new way to test consistency of the CKM picture of CP violation in the quark sector and probe possible new physics. The differences between the apexes (i.e., $\tilde{\rho }-\overline{\rho }$ and $\tilde{\eta }-\overline{\eta }$) are found to be of $\mathcal{O}({\lambda }^2)$ with $\lambda \simeq 0.22$ being the Wolfenstein expansion parameter, and the shapes of these two triangles are found to be insensitive to the two-loop renormalization-group-equation running effects up to the accuracy of $\mathcal{O}\left({\lambda }^4\right)$.

   hep-phhep-exPoS(2021)·1 citation
9. 09*

   Axion strings are superconducting

   Hajime Fukuda🇺🇸 · Aneesh V. Manohar🇺🇸 · Hitoshi Murayama🇺🇸 · Ofri Telem🇺🇸

   We explore the cosmological consequences of the superconductivity of QCD axion strings. Axion strings can support a sizeable chiral electric current and charge, which alters their early universe dynamics. Shrinking axion string loops can become effectively stable remnants called vortons, supported by the electromagnetic force of the string current. Generically, vortons produced by axion strings overclose the universe, unless there are efficient current leakage processes. Furthermore, if a primordial magnetic field (PMF) exists in the early universe, a large current is induced on axion strings, creating a significant drag force from interactions with the surrounding plasma. As a result, the strings are slowed down, which leads to an orders of magnitude enhancement in the number of strings per Hubble volume. Finally, we study the implications for the QCD axion relic abundance. The QCD axion window is shifted by orders of magnitude in some parts of our parameter space.

   hep-phJHEP(2021)·32 citations
10. 10*

    Power-aligned 2HDM: a correlative perspective on $(g-2{)}_{e,\mu }$

    Shao-Ping Li🇨🇳 · Xin-Qiang Li🇨🇳 · Yuan-Yuan Li🇨🇳 · Ya-Dong Yang🇨🇳 · Xin Zhang🇨🇳

    With the hypothesis of minimal flavor violation, we find that there exists a power-aligned relation between the Yukawa couplings of the two scalar doublets in the two-Higgs-doublet model with Hermitian Yukawa matrices. Within such a power-aligned framework, it is found that a simultaneous explanation of the anomalies observed in the electron and muon anomalous magnetic moments can be reached with TeV-scale quasi-degenerate Higgs masses, and the resulting parameter space is also phenomenologically safer under the B-physics, $Z$ and $\tau$ decay data, as well as the current LHC bounds. Furthermore, the flavor-universal power that enhances the charged-lepton Yukawa couplings prompts an interesting correlation between the two anomalies, which makes the model distinguishable from the (generalized) linearly aligned and the lepton-specific two-Higgs-doublet models that address the same anomalies but in a non-correlative manner, and hence testable by future precise measurements.

    hep-phhep-exJHEP(2021)·57 citations
11. 11*

    Electroweak axion string and superconductivity

    Yoshihiko Abe🇯🇵 · Yu Hamada🇯🇵 · Koichi Yoshioka🇯🇵

    We study the axion strings with the electroweak gauge flux in the DFSZ axion model and show that these strings, called the electroweak axion strings, can exhibit superconductivity without fermionic zero modes. We construct three types of electroweak axion string solutions. Among them, the string with $W$-flux can be lightest in some parameter space, which leads to a stable superconducting cosmic string. We also show that a large electric current can flow along the string due to the Peccei-Quinn scale much higher than the electroweak scale. This large current induces a net attractive force between the axion strings with the same topological charge, which opens a novel possibility that the axion strings form Y-junctions in the early universe.

    hep-phastro-ph.COhep-thJHEP(2021)·35 citations
12. 12*

    Jet evolution in a dense QCD medium

    Paul Caucal🇫🇷

    To probe the properties of the quark-gluon plasma created in heavy-ion collisions, a very useful class of observables refers to the propagation of energetic jets. A jet is a collimated spray of particles generated via successive parton branchings, starting with a virtual quark or gluon produced by the collision. When such a jet is produced in the dense environment of a nucleus-nucleus collision, its interactions with the surrounding medium lead to a modification of its properties, phenomenon known as jet quenching. In this thesis, we develop a new theory to describe jet quenching. We compute for the first time the effects of the medium on multiple vacuum-like emissions, that is emissions triggered by the virtuality of the initial parton. We present a new physical picture for jet evolution, with notably a factorisation in time between vacuum-like emissions and medium-induced emissions. This picture is Markovian, hence well suited for a Monte Carlo implementation that we develop in the parton shower JetMed. We then investigate the phenomenological consequences of our new picture on jet observables and especially the jet nuclear modification factor $R_{AA}$, the Soft Drop $z_g$ distribution and the jet fragmentation function. Our Monte Carlo results prove to be in good agreement with the LHC measurements.

    hep-phnucl-th15 citations
13. 13*

    Viscous properties of hot and dense QCD matter in the presence of a magnetic field

    Shubhalaxmi Rath🇮🇳 · Binoy Krishna Patra🇮🇳

    We have studied the effect of strong magnetic field on the viscous properties of hot QCD matter at finite chemical potential by calculating the shear ($\eta$) and bulk ($\zeta$) viscosities. The viscosities are calculated using kinetic theory in the relaxation time approximation. The interactions are incorporated through the quasiparticle masses of partons at strong magnetic field and finite chemical potential. From this study, one can understand the effects of strong magnetic field and chemical potential on the sound attenuation through the Prandtl number (Pl), on the nature of the flow by the Reynolds number (Rl), and on the relative behavior between shear viscosity and bulk viscosity through the ratio $\zeta /\eta$. We have found that, $\eta$ and $\zeta$ get increased in a strong magnetic field and the additional presence of chemical potential further enhances their magnitudes. With the increase of temperature, $\eta$ increases in a strong magnetic field as well as in the absence of magnetic field, whereas $\zeta$ decreases with the temperature, contrary to its increase in the absence of magnetic field. We have observed that, the Prandtl number gets increased in the presence of strong magnetic field and chemical potential as compared to the isotropic one, but it always remains larger than 1, thus the momentum diffusion largely affects the sound attenuation in the medium. The Reynolds number gets lowered than 1 in a strong magnetic field and it becomes further decreased in an additional presence of chemical potential, so the kinematic viscosity dominates over the characteristic length scale of the system. Finally, $\zeta /\eta$ becomes larger than 1, contrary to its value in the absence of magnetic field and chemical potential where it is less than 1, so the bulk viscosity prevails over the shear viscosity for the hot and dense QCD matter in the presence of a strong magnetic field.

    hep-phnucl-thEPJC(2021)·19 citations
14. 14*

    High quality Nelson-Barr solution to the strong CP problem with $\theta =\pi$

    Gilad Perez🇮🇱 · Aviv Shalit🇮🇱

    We discuss composite UV completions of the Nelson-Barr(NB) solution to the strong CP problem. In our construction, the CP symmetry is broken spontaneously by the dynamics of a hidden QCD at $\theta =\pi$. We focus on the minimal implementation of the NB construction where the visible sector contains one extra pair of vector-like up/down quarks. We show that the minimal NB theory suffers from a quality problem, and discuss how composite UV completions may resolve it. We present a simple calculable scheme, free of a quality problem, where dynamical CP violation in the hidden sector is mediated through a scalar portal to the visible sector, which successfully realizes the NB construction.

    hep-phJHEP(2021)·22 citations
15. 15*

    The Fragmentation Spectrum from Space-Time Reciprocity

    Duff Neill🇺🇸

    Analyzing the single inclusive annihilation spectrum of charged hadrons in $e^{+}{e}^{-}$ collisions, I confront the hadronization hypothesis of local parton-hadron duality with a systematic resummation of the dependence on the small energy fraction. This resummation is based on the reciprocity between time-like and space-like splitting processes in $4-2ϵ$-dimensions, which I extend to resum all the soft terms of the cross-section for inclusive jet production. Under the local-parton-hadron duality hypothesis, the resulting distribution of jets essentially determines the spectrum of hadrons as the jet radius goes to zero. Thus I take the resummed perturbative jet function as the non-perturbative fragmentation function with an effective infra-red coupling. I find excellent agreement with data, and comment on the mixed leading log approximation previously used to justify local parton-hadron duality.

    hep-phnucl-thJHEP(2021)·9 citations
16. 16*

    Enhanced Supernova Axion Emission and its Implications

    Pierluca Carenza🇮🇹 · Bryce Fore🇺🇸 · Maurizio Giannotti🇺🇸 · Alessandro Mirizzi🇮🇹 · Sanjay Reddy🇺🇸

    We calculate the axion emission rate from reactions involving thermal pions in matter encountered in supernovae and neutron star mergers, identify unique spectral features, and explore their implications for astrophysics and particle physics. We find that it is about 2-5 times larger than nucleon-nucleon bremsstrahlung, which in past studies was considered to be the dominant process. The axion spectrum is also found be much harder. Together, the larger rates and higher axion energies imply a stronger bound on the mass of the QCD axion, and better prospects for direct detection in a large underground neutrino detector from a nearby galactic supernova.

    hep-phastro-ph.HEastro-ph.SRPRL(2021)·143 citations
17. 17*

    Measurement of Differential Cross Sections for ${\nu }_{\mu }$-Ar Charged-Current Interactions with Protons and no Pions in the Final State with the MicroBooNE Detector

    MicroBooNE collaboration: P. Abratenko🇺🇸 · M. Alrashed🇺🇸 · R. An🇺🇸 · J. Anthony🇬🇧 · J. Asaadi🇺🇸 · A. Ashkenazi🇺🇸 · S. Balasubramanian🇺🇸 · B. Baller🇺🇸 · C. Barnes🇺🇸 · G. Barr🇬🇧 · V. Basque🇬🇧 · L. Bathe-Peters🇺🇸 and 172 other authors

    We present an analysis of MicroBooNE data with a signature of one muon, no pions, and at least one proton above a momentum threshold of 300 MeV/c (CC0$\pi$Np). This is the first differential cross section measurement of this topology in neutrino-argon interactions. We achieve a significantly lower proton momentum threshold than previous carbon and scintillator-based experiments. Using data collected from a total of approximately $1.6\times 10^{20}$ protons-on-target, we measure the muon neutrino cross section for the CC0$\pi$Np interaction channel in argon at MicroBooNE in the Booster Neutrino Beam which has a mean energy of around 800 MeV. We present the results from a data sample with estimated efficiency of 29\% and purity of 76\% as differential cross sections in five reconstructed variables: the muon momentum and polar angle, the leading proton momentum and polar angle, and the muon-proton opening angle. We include smearing matrices that can be used to "forward-fold" theoretical predictions for comparison with these data. We compare the measured differential cross sections to a number of recent theory predictions demonstrating largely good agreement with this first-ever data set on argon.

    ↳ hep-exhep-phnucl-exnucl-th+1PRD(2020)·91 citations
18. 18*

    The x-dependence of hadronic parton distributions: A review on the progress of lattice QCD

    Martha Constantinou🇺🇸

    In this article, we review recent lattice calculations on the $x$-dependence of parton distributions, with the latter providing information on hadron structure. These calculations are based on matrix elements of boosted hadrons coupled to non-local operators and can be related to the standard, light-cone distribution functions via an appropriate factorization formalism. There is significant progress in several directions, including calculations of flavor singlet parton distribution functions (PDFs), first calculations of generalized parton distributions (GPDs), as well as the implementation of some of the approaches for the transverse-momentum-dependent PDFs (TMD PDFs). This new direction of lattice calculations is particularly interesting for phenomenological fits on experimental data sets, as the lattice results can help to improve the constraints on the distribution functions.

    ↳ hep-lathep-exhep-phhep-thEPJA(2021)·127 citations
19. 19*

    Correspondence between Israel-Stewart and first-order causal and stable hydrodynamics for Bjorken-expanding baryon-rich systems with vanishing particle masses

    Arpan Das🇵🇱 · Wojciech Florkowski🇵🇱 · Radoslaw Ryblewski🇵🇱

    We obtain an exact correspondence between the dynamical equations in Israel-Stewart (IS) theory and first-order causal and stable (FOCS) hydrodynamics for a boost-invariant system with an ideal gas equation of state at finite baryon chemical potential. Explicit expressions for the temperature and chemical potential dependence of the regulators in the FOCS theory are given in terms of the kinetic coefficients and constant relaxation time of the IS theory. Using the correspondence between the IS and FOCS theory, stability conditions for a charged fluid which are known in the FOCS approach are applied and one finds that the IS theory considered is unstable.

    ↳ nucl-thhep-phPRD(2021)·7 citations
20. 20*

    Cosmic ray positrons from compact binary millisecond pulsars

    Manuel Linares🇪🇸 · Michael Kachelriess🇳🇴

    A new population of neutron stars has emerged during the last decade: compact binary millisecond pulsars (CBMSPs). Because these pulsars and their companion stars are in tight orbits with typical separations of $10^{11}$ cm, their winds interact strongly forming an intrabinary shock. Electron-positron pairs reaccelerated at the shock can reach energies of about 10 TeV, which makes this new population a potential source of GeV-TeV cosmic ray positrons. We present an analytical model for the fluxes and spectra of positrons from intrabinary shocks of CBMSPs. We find that the minimum energy $E_{\min }$ of the pairs that enter the shock is critical to quantify the energy spectrum with which positrons are injected into the interstellar medium. We measure for the first time the Galactic scale height of CBMSPs, $z_e=0.4\pm 0.1$ kpc, after correcting for an observational bias against finding them close to the Galactic plane. From this, we estimate a local density of 5-9 kpc${}^{-3}$ and an extrapolated total of 2-7 thousand CBMSPs in the Galaxy. We then propagate the pairs in the isotropic diffusion approximation and find that the positron flux from the total population is about two times higher than that from the 52 currently known systems. For $E_{\min }$ between 1 and 50 GeV, our model predicts only a minor contribution from CBMSPs to the diffuse positron flux at 100 GeV observed at Earth. We also quantify the effects of anisotropic transport due to the ordered Galactic magnetic field, which can change the diffuse flux from nearby sources drastically. Finally, we find that a single "hidden" CBMSP close to the Galactic plane can yield a positron flux comparable to the AMS-02 measurements at 600 GeV if its line-of-sight to Earth is along the ordered Galactic field lines, while its combined electron and positron flux at higher energies would be close to the measurements of CALET, DAMPE and Fermi-LAT.

    ↳ astro-ph.HEhep-phJCAP(2021)·22 citations
21. 21*

    Quantum Information for Particle Theorists

    Joseph D. Lykken🇺🇸

    Lectures given at the Theoretical Advanced Study Institute (TASI 2020), 1-26 June 2020. The topics covered include quantum circuits, entanglement, quantum teleportation, Bell inequalities, quantum entropy and decoherence, classical versus quantum measurement, the area law for entanglement entropy in quantum field theory, and simulating quantum field theory on a quantum computer. Along the way we confront the fundamental sloppiness of how we all learned (and some of us taught) quantum mechanics in college. Links to a Python notebook and Mathematica notebooks will allow the reader to reproduce and extend the calculations, as well as perform five experiments on a quantum simulator.

    ↳ quant-phhep-lathep-phPoS(2021)·12 citations
22. 22*

    Bounds on velocity-dependent dark matter-proton scattering from Milky Way satellite abundance

    Karime Maamari🇺🇸 · Vera Gluscevic🇺🇸 · Kimberly K. Boddy🇺🇸 · Ethan O. Nadler🇺🇸 · Risa H. Wechsler🇺🇸

    We use the latest measurements of the Milky Way satellite population from the Dark Energy Survey and Pan-STARRS1 to infer the most stringent astrophysical bound to date on velocity-dependent interactions between dark matter particles and protons. We model the momentum-transfer cross section as a power law of the relative particle velocity $v$ with a free normalizing amplitude, ${\sigma }_{\text{MT}}={\sigma }_0{v}^n$, to broadly capture the interactions arising within the non-relativistic effective theory of dark matter-proton scattering. The scattering leads to a momentum and heat transfer between the baryon and dark matter fluids in the early Universe, ultimately erasing structure on small physical scales and reducing the abundance of low-mass halos that host dwarf galaxies today. From the consistency of observations with the cold collisionless dark matter paradigm, using a new method that relies on the most robust predictions of the linear perturbation theory, we infer an upper limit on ${\sigma }_0$ of $1.4\times 10^{-23}$, $2.1\times 10^{-19}$, and $1.0\times 10^{-12}{\mathrm{cm}}^2$, for interaction models with $n=2,4,6$, respectively, for a dark matter particle mass of $10\mathrm{MeV}$. These results improve observational limits on dark matter--proton scattering by orders of magnitude and thus provide an important guide for viable sub-GeV dark matter candidates.

    ↳ astro-ph.COhep-phApJL(2021)·76 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.