Thu·Mar 31, 2022Thursday·March 31, 2022

1. 01*

   Snowmass2021 Cosmic Frontier White Paper: Probing dark matter with small-scale astrophysical observations

   Richard Brito🇵🇹 · Sukanya Chakrabarti🇺🇸 · Sebastien Clesse🇧🇪 · Cora Dvorkin🇺🇸 · Juan Garcia-Bellido🇪🇸 · Joel Meyers🇺🇸 · Ken K. Y. Ng🇺🇸 · Andrew L. Miller🇧🇪 · Sarah Shandera🇺🇸 · Ling Sun🇦🇺

   The current understanding of dark matter comes largely from measurements of the total matter content in the universe, from the distribution of gravitating matter on very large scales, and from rotation curves and velocity dispersions on sub-galactic scales. However, small-scale structure may well hold the key to unlocking the particle physics of the still-mysterious 85% of matter in the universe. Novel small-scale astrophysical probes of new particles and dark matter will become possible with a large data volume of high-precision measurements enabled by next-generation gravitational-wave detectors and advanced astrometry instruments. Cosmic microwave background and large-scale structure surveys will provide complementary constraints on dark matter models with unique small-scale signatures. We lay out the studies of small-scale structures and compact objects as dark matter probes, and summarize the requirements to achieve the goals.

   hep-phastro-ph.COgr-qc22 citations
2. 02*

   Bhabha scattering in the gauge-Higgs unification

   Shuichiro Funatsu🇯🇵 · Hisaki Hatanaka🇯🇵 · Yutaka Hosotani🇯🇵 · Yuta Orikasa🇨🇿 · Naoki Yamatsu🇯🇵

   We examine effects of $Z^{\prime }$ bosons in gauge-Higgs unification (GHU) models at ${\mathrm{e}}^{+}{\mathrm{e}}^{-}\to {\mathrm{e}}^{+}{\mathrm{e}}^{-}$ Bhabha scatterings. We evaluate differential cross sections in Bhabha scatterings including $Z^{\prime }$ bosons in two types of $\mathrm{SO}(5)\times \mathrm{U}(1)\times \mathrm{SU}(3)$ GHU models. We find that deviations of differential cross sections in the GHU models from those in the SM can be seen at $\sqrt{s}=250\mathrm{GeV}$. With $80\%$-longitudinally polarized electron and $30\%$-longitudinally polarized positron beams, the left-right asymmetries in the GHU A- and B-models are resolved at more than $3\sigma$ at $L_{\mathrm{int}}=250{\mathrm{fb}}^{-1}$. We also show that Bhabha scattering with scattering angle less than 100 mrad can be safely used as luminosity measurements in ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ colliders since the effects of $Z^{\prime }$ bosons are well suppressed for small scattering angle. We propose a new observable which can be measured at future TeV-scale ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ linear colliders.

   hep-phPRD(2022)·4 citations
3. 03*

   Towards (semi) exclusive cross section measurements and modelling

   Maria B. Barbaro🇮🇹

   Semi-inclusive neutrino-nucleus scattering, corresponding to the simultaneous detection of a lepton and one or more hadrons in the final state, is shown to be much more sensitive to nuclear effects than the inclusive process. The theoretical description of the semi-inclusive process is illustrated and some comparisons of relativistic plane wave impulse approximation (RPWIA) predictions with recent MicroBooNE, T2K and MINERvA data on argon and carbon are shown. The merit of new variables constructed to enhance particular nuclear effects is also illustrated and future developments going beyond the RPWIA approach are outlined.

   hep-phnucl-thPoS(2022)·1 citation
4. 04*

   ${\tau }_{B_c}$ in the Standard Model

   Jason Aebischer🇨🇭 · Benjamín Grinstein🇺🇸

   The Standard Model prediction of the $B_c$ lifetime is discussed, together with the dominant uncertainties and strategies on how to improve them. Furthermore, a new method to compute the $B_c$ lifetime based on the operator product expansion is proposed. It relies on differences of $B,D$ and $B_c$ meson decay rates, in which the free-quark contributions cancel out, reducing the uncertainty of the theory prediction.

   hep-phPoS(2022)·1 citation
5. 05*

   Momentum transport properties of a hot and dense QCD matter in a weak magnetic field

   Shubhalaxmi Rath🇮🇳 · Sadhana Dash🇮🇳

   We have studied the momentum transport properties of a hot and dense QCD matter in the presence of weak magnetic field by determining the shear ($\eta$) and bulk ($\zeta$) viscosities in the relaxation time approximation of kinetic theory. The dependence of $\eta$ and $\zeta$ on the temperature has been explored in the presence of weak magnetic field ($B$-field) and finite chemical potential ($\mu$). It is observed that both shear and bulk viscosities get decreased in the presence of a weak magnetic field, whereas the finite chemical potential increases these viscosities, specifically at low temperatures. This study is important to understand the sound attenuation through the Prandtl number (Pr), the nature of the flow through the Reynolds number (Re), the fluidity and location of transition point of the matter through the ratios $\eta /s$ and $\zeta /s$ ($s$ is the entropy density), respectively. The Prandtl number is observed to increase in the weak magnetic field, whereas the presence of a finite chemical potential reduces its magnitude as compared to the scenario of absence of $B$-field and $\mu$. However, Pr still remains larger than unity, indicating that the energy dissipation due to the sound attenuation is mostly governed by the momentum diffusion. It is noticed that the weak magnetic field makes the Reynolds number larger, whereas the chemical potential makes it smaller than that in the absence of $B$-field and $\mu$. We have observed that the ratio $\eta /s$ decreases in the weak magnetic field regime, whereas the finite chemical potential increases its value, but the ratio $\zeta /s$ is found to decrease in the presence of weak magnetic field as well as finite chemical potential.

   hep-phhep-thnucl-thEPJC(2022)·21 citations
6. 06*

   Exclusive B-meson semileptonic decays from unitarity and lattice QCD

   G. Martinelli🇮🇹 · M. Naviglio🇮🇹 · S. Simula🇮🇹 · L. Vittorio🇮🇹

   We examine the semileptonic $B\to D^{(\ast )}\ell {\nu }_{\ell }$ and $B\to \pi \ell {\nu }_{\ell }$ decays adopting the unitarity-based Dispersive Matrix (DM) method, which allows to determine the shape of the relevant hadronic form factors (FFs) in their whole kinematical range, using only lattice QCD results available at large values of the 4-momentum transfer without making any assumption on their momentum dependence. Moreover, the experimental data are not used to constrain the shape of the FFs, but only to obtain our final exclusive determination of $|V_{cb}|$ and $|V_{ub}|$, namely: $|V_{cb}|\cdot 10^3=41.1\pm 1.0$ and $|V_{ub}|\cdot 10^3=3.88\pm 0.32$, which are consistent with the latest inclusive determinations at the $1\sigma$ level or better. Our calculation of the FFs allows to obtain pure theoretical estimates of the $\tau /\mu$ ratios of differential decay rates, $R(D)=0.296\pm 0.008$ and $R(D^{\ast })=0.275\pm 0.008$, which turn out to be compatible with the experimental world averages within $\simeq 1.4$ standard deviations.

   hep-phhep-exhep-latPoS(2021)·11 citations
7. 07*

   Bounds on anomalous quartic $WWZ\gamma$ couplings in $e^{-}p$ collisions at the FCC-he

   E. Gurkanli🇹🇷

   Non-Abelian structure of the Standard Model predicts the self-interactions of gauge bosons triple gauge couplings (TGC) and quartic gauge couplings (QGC). On the other hand, it is also important to determine the deviations from Standard Model (SM) via anomalous triple gauge couplings (aTGC) and anomalous quartic gauge couplings (aQGC) to test the nature of the Standard Model (SM) and to see the effects of new physics arising from the beyond standard model (BSM). In this study, we focus on the $e^{-}p\to jZ\gamma {\nu }_e\to j(l^{+}{l}^{-})\gamma {\nu }_e$ process to examine the $WWZ\gamma$ anomalous quartic gauge couplings (aQGC) at the Future Circular Collider-hadron electron (FCC-he) with center-of-mass energy $\sqrt{s}=5.29$ TeV using with a model-independent way in the effective theory approach. A Cut-based method are applied to analyse the signal and relevant SM background. Using with the total cross-sections, we constrained on the anomalous $f_{T,i=0,1,2,5,6,7}/{\Lambda }^4$ couplings arising from dimension-8 operators at $95\%$ Confidence Level (C.L.) for the dilepton decay of the $Z$-boson. The results are composed with integrated luminosities of $\mathcal{L}=1,2$ and $3$ $\mathrm{a}{\mathrm{b}}^{-1}$ under the systematic uncertainties of $\%0$, $\%5$ and $\%10$. In the calculations, we use the form factor to eleminate the effects of the violation of unitarity. With this, we obtained the limits for the energy scale of the form factor $\Lambda =1$ TeV. In addition to all this, we use the adventages of $ep$ collisions for analysing the process with much cleaner environment and lower background effects comparing with the $pp$ collisions. The obtained sensitivities on $f_{T,i=0,1,2,5,6,7}/{\Lambda }^4$ are comparable with the experimental results and related phenomenological studies in the literature.

   hep-phJ.Phys.G(2023)·5 citations
8. 08*

   Heavy quarks and jets as probes of the QGP

   Liliana Apolinário (1 and 2)🇵🇹 · Yen-Jie Lee (3)🇺🇸 · Michael Winn (4) ((1) LIP, (2) Instituto Superior Técnico (IST), Universidade de Lisboa, (3) Massachusetts Institute of Technology (MIT), (4) Département de Physique Nucléaire (DPhN), Institut de Recherche sur les lois Fondamentales de l'Univers (IRFU) CEA - Saclay)🇫🇷

   Quark-Gluon Plasma (QGP), a QCD state of matter created in ultra-relativistic heavy-ion collisions, has remarkable properties, including, for example, a low shear viscosity over entropy ratio. By detecting the collection of low-momentum particles that arise from the collision, it is possible to gain quantitative insight into the created matter. However, its fast evolution and thermalization properties remain elusive. Only using high momentum objects as probes of QGP can unveil its constituents at different wavelengths. In this review, we attempt to provide a comprehensive picture of what was, so far, possible to infer about QGP given our current theoretical understanding of jets, heavy-flavor, and quarkonia. We will bridge the resulting qualitative picture to the experimental observations done at the LHC and RHIC. We will focus on the phenomenological description of experimental observations, provide a brief analytical summary of the description of hard probes, and an outlook on the main difficulties we will need to surpass in the following years. To benchmark QGP-related effects, we will also address nuclear modifications to the initial state and hadronization effects.

   hep-phnucl-exnucl-thPPNP(2022)·215 citations
9. 09*

   Instanton effects in Euclidean vacuum, real time production and in the light front wave functions

   Edward Shuryak🇺🇸 · Ismail Zahed🇺🇸

   Nontrivial topological structures of non-Abelian gauge fields were discovered in the 1970's. Instanton solutions, describing vacuum tunneling through topological barriers, have fermionic zero modes which are at the origin of ${}^{\prime }$t Hooft effective Lagrangian. In the 1980's instanton ensembles have been used to explain chiral symmetry breaking. In the 1990's a large set of numerical simulations were performed deriving Euclidean correlation functions. The special role of scalar diquarks in nucleons, and color superconductivity in dense quark matter have been elucidated. In these lectures, we discuss further developments of physics related to gauge topology. We show that the instanton-antiinstanton "streamline" configurations describe "sphaleron transitions" in high energy collisions, which result in production of hadronic clusters with nontrivial topological/chiral charges. (They are not yet observed, but discussions of dedicated experiments at LHC and RHIC are ongoing.) Another new direction is instanton effects in hadronic spectroscopy, both in the rest frame and on the light front. We will discuss their role in central and spin-dependent potentials, formfactors and antiquark nuclear "sea". Finally, we summarize the advances in the semiclassical theory of deconfinement, and chiral phase transitions at finite temperature, in QCD and in some of its "deformed" versions.

   hep-phActa Phys.Polon.B(2022)·0 citations
10. 10*

    Anomaly-free ALP from non-Abelian flavor symmetry

    Chengcheng Han🇨🇳 · M.L. López-Ibáñez🇪🇸 · Aurora Melis🇪🇪 · Óscar Vives🇪🇸 · Jin Min Yang🇨🇳

    Motivated by the Xenon1T excess in electron-recoil measurements, we investigate the prospects of probing axion-like particles (ALP) in lepton flavor violation experiments. In particular, we identify such ALP as a pseudo-Goldstone from the spontaneous breaking of the flavor symmetries that explain the mixing structure of the Standard Model leptons. We present the case of the flavor symmetries being a non-Abelian U(2) and the ALP originating from its U(1) subgroup, which is anomaly-free with the Standard Model group. We build two explicit realistic examples that reproduce leptonic masses and mixings and show that the ALP which is consistent with Xenon1T anomaly could be probed by the proposed LFV experiments.

    hep-phJHEP(2022)·11 citations
11. 11*

    Domain walls seeding the electroweak phase transition

    Simone Blasi🇧🇪 · Alberto Mariotti🇧🇪

    Topological defects can act as local impurities that seed cosmological phase transitions. In this paper we study the case of domain walls, and how they can affect the electroweak phase transition in the Standard Model extended with a $Z_2$-odd scalar singlet. When the transition is two-step, the early breaking of the $Z_2$ symmetry implies the formation of domain walls which can then act as nucleation sites for the second step. We develop a method based on dimensional reduction to calculate the rate of the catalyzed phase transition within the 3d theory on the domain wall surface. By comparison with the standard homogeneous rate, we conclude that the seeded phase transition is generically faster and it ultimately determines the way the phase transition is completed. We comment on the phenomenological implications for gravitational waves and baryogenesis.

    hep-phhep-thPRL(2022)·83 citations
12. 12*

    The Role of the Neutrino Form Factors in the Energy Loss Rates of Pair Annihilation Process

    C. Aydın🇹🇷

    The stellar energy loss rates due to the production of the neutrino pair process $e^{+}{e}^{-}\to (W,Z,\gamma )\to {\nu }_e\overline{{\nu }_e}$ are calculated in the minimal extension of Standard Model with electromagnetic properties of Dirac neutrinos which takes the account of the contribution of the neutrino charge radius, anapole moment and dipole moments. We have shown that the contribution of the electron neutrino's dipole moment is small compared with that of the charge radius. The obtained results are also considered with results obtained using the Standard Model.

    hep-phCPC(2022)·2 citations
13. 13*

    Hadronic vacuum polarization contribution to the muon $g-2$ in holographic QCD

    Josef Leutgeb🇦🇹 · Anton Rebhan🇦🇹 · Michael Stadlbauer🇩🇪

    We evaluate the leading-order hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon with two light flavors in minimal hard-wall and soft-wall holographic QCD models, as well as in simple generalizations thereof, and compare with the rather precise results available from dispersive and lattice approaches. While holographic QCD cannot be expected to shed light on the existing small discrepancies between the latter, this comparison in turn provides useful information on the holographic models, which have been used to evaluate hadronic light-by-light contributions where errors in data-driven and lattice approaches are more sizable. In particular, in the hard-wall model that has recently been used to implement the Melnikov-Vainshtein short-distance constraint on hadronic light-by-light contributions, a matching of the hadronic vacuum polarization to the data-driven approach points to the same correction of parameters that has been proposed recently in order to account for next-to-leading order effects.

    hep-phhep-thPRD(2022)·9 citations
14. 14*

    Probing neutrino magnetic moments and the XENON1T excess with coherent elastic solar neutrino scattering

    Yu-Feng Li🇨🇳 · Shuo-yu Xia🇨🇳

    The detection potential of the active neutrino magnetic moment (${\nu }_a$MM) and the active sterile transition magnetic moment (${\nu }_s$MM) of the solar neutrino CE$\nu$NS process in future Dark Matter direct detection experiments is studied and compared with the respective allowed range to explain the Xenon1T excess. We find that the sensitivity to the ${\nu }_a$MM approaches to the level between $10^{-10}{\mu }_B$ and $10^{-11}{\mu }_B$, which is dominantly limited by the detection threshold. On the other hand, the future solar neutrino CE$\nu$NS detection would be powerful in probing the ${\nu }_s$MM for the sterile neutrino mass below 10 MeV, which could unambiguously test the ${\nu }_s$MM explanation of the Xenon1T excess. The sensitivity in the general framework with both ${\nu }_a$MM and ${\nu }_s$MM contributions is also derived.

    hep-phPRD(2022)·18 citations
15. 15*

    Exponential Approach to the Hydrodynamic Attractor in Yang-Mills Kinetic Theory

    Xiaojian Du🇩🇪 · Michal P. Heller🇧🇪 · Sören Schlichting🇩🇪 · Viktor Svensson🇸🇪

    We use principal component analysis to study the hydrodynamic attractor in Yang-Mills kinetic theory undergoing the Bjorken expansion with Color Glass Condensate initial conditions. The late time hydrodynamic attractor is characterized by a single principal component determining the overall energy scale. How it is reached is governed by the disappearance of single subleading principal component characterizing deviations of the pressure anisotropy, the screening mass and the scattering rate. We find that for wide range of couplings the approach to the hydrodynamic attractor at late times is well described by an exponential. Its decay rate dependence on the coupling turns out to translate into a simple dependence on the shear viscosity to entropy density ratio.

    hep-phhep-thnucl-thPRD(2022)·34 citations
16. 16*

    From ten-flavor tests of the $\beta$-function to ${\alpha }_s$ at the Z-pole

    Zoltán Fodor🇩🇪 · Kieran Holland🇺🇸 · Julius Kuti🇺🇸 · Chik Him Wong🇩🇪

    New tests are applied to two $\beta$-functions of the much-discussed BSM model with ten massless fermion flavors in the fundamental representation of the SU(3) color gauge group. The renormalization scheme of the two $\beta$-functions is defined on the gauge field gradient flow in respective finite or infinite physical volumes at zero lattice spacing. Recently published results in the ten-flavor theory led to indicators of an infrared fixed point (IRFP) in the finite-volume step $\beta$-function in the strong coupling regime of the theory arXiv:2004.00754. We analyze our substantially extended set of ten-flavor lattice ensembles at strong renormalized gauge couplings and find no evidence or hint for IRFP in the finite-volume step $\beta$-function within controlled lattice reach. We also discuss new ten-flavor tests of the recently introduced lattice definition and algorithmic implementation of the $\beta$-function defined on the gradient flow of the gauge field over infinite Euclidean space-time in the continuum. Originally we introduced this new algorithm to match finite-volume step $\beta$-functions in massless near-conformal gauge theories with the infinite-volume $\beta$-function reached in the chiral limit from small fermion mass deformations of spontaneous chiral symmetry breaking. Results from the lattice analysis of the ten-flavor infinite-volume $\beta$-function are consistent with the absence of IRFP from our step $\beta$-function based analysis. We make important contact at weak coupling in infinite volume with gradient flow based three-loop perturbation theory, serving as a first pilot study toward the long-term goal of developing alternate approach to the determination of the strong coupling ${\alpha }_s$ at the Z-boson pole in QCD.

    ↳ hep-lathep-phPoS(2022)·11 citations
17. 17*

    Axial U(1) symmetry at high temperatures in $N_f=2+1$ lattice QCD with chiral fermions

    Sinya Aoki🇯🇵 · Yasumichi Aoki🇯🇵 · Hidenori Fukaya🇯🇵 · Shoji Hashimoto🇯🇵 · Issaku Kanamori🇯🇵 · Takashi Kaneko🇯🇵 · Yoshifumi Nakamura🇯🇵 · Christian Rohrhofer🇯🇵 · Kei Suzuki (JLQCD Collaboration)🇯🇵

    We study the $U(1{)}_A$ anomaly in the high-temperature phase of $N_f=2+1$ lattice QCD with chiral fermions. Gauge ensembles are generated with Möbius domain-wall (MDW) fermions, and in the measurements the determinant is reweighted to that of overlap fermions. We report the results for the overlap Dirac spectrum, $U(1{)}_A$ susceptibility, and topological susceptibility at $T=204$ and $175$ MeV.

    ↳ hep-lathep-phPoS(2022)·2 citations
18. 18*

    Chiral asteroseismology: seismic oscillations caused by chiral transport in neutron stars and supernovae

    Sota Hanai🇯🇵 · Naoki Yamamoto🇯🇵

    We study the novel asteroseismology of the chiral magnetic wave (CMW) of the quark number density in relativistic quark matter inside neutron stars and core-collapse supernovae and the chiral vortical wave (CVW) of the neutrino number density in relativistic neutrino matter at the core of supernovae. We call the oscillation modes for these chiral waves the chiral magnetic mode (CM-mode) and chiral vortical mode (CV-mode), respectively. We derive the dispersion relations of these new modes in the presence of the chirality flipping due to the finite quark mass and diffusion. We then estimate the possible frequencies of these modes and amplitudes of the resulting gravitational waves. In particular, since the CM-mode can exist only in quark matter with nearly gapless quarks (such as the two-flavor color superconductivity) for a sufficiently strong magnetic field, corresponding gravitational waves provide a new possible probe for such quark matter and the magnetic field in neutron stars.

    ↳ astro-ph.HEhep-phnucl-thJCAP(2023)·5 citations
19. 19*

    Analytical scaling solutions for the evolution of cosmic domain walls in a parameter-free velocity-dependent one-scale model

    P. P. Avelino🇵🇹 · D. Grüber🇵🇹 · L. Sousa🇵🇹

    We derive an analytical approximation for the linear scaling evolution of the characteristic length $L$ and the root-mean-squared velocity ${\sigma }_v$ of standard frictionless domain wall networks in Friedmann-Lemaître-Robertson-Walker universes with a power law evolution of the scale factor $a$ with the cosmic time $t$ ($a\propto t^{\lambda }$). This approximation, obtained using a recently proposed parameter-free velocity-dependent one-scale model for domain walls, reproduces well the model predictions for $\lambda$ close to unity, becoming exact in the $\lambda \to 1^{-}$ limit. We use this approximation, in combination with the exact results found for $\lambda =0$, to obtain a fit to the model predictions valid for $\lambda \in [0,1[$ with a maximum error of the order of $1\%$. This fit is also in good agreement with the results of field theory numerical simulations, specially for $\lambda \in [0.9,1[$. Finally, we explicitly show that the phenomenological energy-loss parameter of the original velocity-dependent one-scale model for domain walls vanishes in the $\lambda \to 1^{-}$ limit and discuss the implications of this result.

    ↳ astro-ph.COgr-qchep-phhep-thSymmetry(2022)·8 citations
20. 20*

    Geometrical Scaling of Direct Photons in Relativistic Heavy Ion and d+Au Collisions

    Vladimir Khachatryan🇺🇸 · Michal Praszalowicz🇵🇱

    In this paper, we show that multiplicity spectra of direct photons in A+A and d+Au collisions at different centrality classes and different energies exhibit geometrical scaling, {\em i.e.}, they depend on a specific combination of number of participants $N_{\mathrm{part}}$, collisions energy $W$, and transverse momentum $p_T$ -- called saturation scale -- rather than on all these three variables separately. In particular, the dependence on the geometry of collisions encoded in the dependence on $N_{\mathrm{part}}$ is in agreement with the expectations based on the Color Glass Condensate theory.

    ↳ nucl-thhep-phNPA(2023)·2 citations
21. 21*

    Path integrals of perturbative strings on curved backgrounds from string geometry theory

    Matsuo Sato🇯🇵 · Yuji Sugimoto🇰🇷 · Kunihito Uzawa🇯🇵

    String geometry theory is one of the candidates of the non-perturbative formulation of string theory. In this paper, from the closed bosonic sector of string geometry theory, we derive path integrals of all order perturbative strings on all the string backgrounds, $G_{\mu \nu }(x)$, $B_{\mu \nu }(x)$, and $\Phi (x)$, by considering fluctuations around the string background configurations, which are parametrized by the string backgrounds.

    ↳ hep-thgr-qchep-phmath.DG+1PRD(2022)·9 citations
22. 22*

    Analytical insight into dark matter subhalo boost factors for Sommerfeld-enhanced $s$- and $p$-wave $\gamma$-ray signals

    Gaétan Facchinetti🇧🇪 · Martin Stref🇫🇷 · Thomas Lacroix🇪🇸 · Julien Lavalle🇫🇷 · Judit Pérez-Romero🇪🇸 · David Maurin🇫🇷 · Miguel A. Sánchez-Conde🇪🇸

    As searches for thermal and self-annihilating dark matter (DM) intensify, it becomes crucial to include as many relevant physical processes and ingredients as possible to refine signal predictions, in particular those which directly relate to the intimate properties of DM. We investigate the combined impact of DM subhalos and of the (velocity-dependent) Sommerfeld enhancement of the annihilation cross section. Both features are expected to play an important role in searches for thermal DM particle candidates with masses around or beyond TeV, or in scenarios with a light dark sector. We provide a detailed analytical description of the phenomena at play, and show how they scale with the subhalo masses and the main Sommerfeld parameters. We derive approximate analytical expressions that can be used to estimate the overall boost factors resulting from these combined effects, from which the intricate phenomenology can be better understood. DM subhalos lead to an increase of the Sommerfeld effect by several orders of magnitude (for both $s$- and $p$-wave annihilation processes), especially on resonances, which makes them critical to get sensible gamma-ray signal predictions for typical targets of different masses (from dwarf galaxies to galaxy clusters).

    ↳ astro-ph.COastro-ph.GAastro-ph.HEhep-phJCAP(2023)·10 citations
23. 23*

    Could fresh lava be (warm) dark matter?

    Mark R. Lovell (University of Iceland)🇮🇸

    Dark matter models can be classified according to their impact on the properties of galaxies, including cold dark matter (CDM), warm dark matter (WDM), self-interacting dark matter (SIDM) and fuzzy dark matter (FDM). In celebration of April Fool's Day, and also of the 1-year anniversary of the start of the 2022 volcanic eruption at Fagradalsfjall here in Iceland, we explore fresh lava as a candidate for WDM specifically. We verify first hand that lava is indeed warm (exhibits free-streaming and retains temperature for several months after the eruption ends, is 1000K, sets fire to grass, can feel one's eyebrows singe at a distance of 4m) and dark once sufficiently decoupled from its source of production.

    ↳ astro-ph.COhep-ph1 citation

* 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.