Wed·Sep 8, 2021Wednesday·September 8, 2021

1. 01*

   Les Houches Lectures on Indirect Detection of Dark Matter

   Tracy R. Slatyer🇺🇸

   These lectures, presented at the 2021 Les Houches Summer School on Dark Matter, provide an introduction to key methods and tools of indirect dark matter searches, as well as a status report on the field circa summer 2021. Topics covered include the possible effects of energy injection from dark matter on the early universe, methods to calculate both the expected energy distribution and spatial distribution of particles produced by dark matter interactions, an outline of theoretical models that predict diverse signals in indirect detection, and a discussion of current constraints and some claimed anomalies. These notes are intended as an introduction to indirect dark matter searches for graduate students, focusing primarily on intuition-building estimates and useful concepts and tools.

   hep-phastro-ph.COastro-ph.HESciPost Phys.Lect.Notes(2022)·78 citations
2. 02*

   Lepton Anomalous Magnetic Moment with Singlet-Doublet Fermion Dark Matter in Scotogenic $U(1{)}_{L_{\mu }-L_{\tau }}$ Model

   Debasish Borah (1)🇮🇳 · Manoranjan Dutta (2)🇮🇳 · Satyabrata Mahapatra (2)🇮🇳 · Narendra Sahu (2) ((1) Indian Institute of Technology Guwahati, (2) Indian Institute of Technology Hyderabad)🇮🇳

   We study an extension of the minimal gauged $L_{\mu }-L_{\tau }$ model in order to explain the anomalous magnetic moments of muon and electron simultaneously. Presence of an additional scalar doublet $\eta$ and an in-built $Z_2$ symmetry under which the right handed singlet fermions and $\eta$ are odd, leads to light neutrino mass in scotogenic fashion along with a stable dark matter candidate. In spite of the possibility of having positive and negative contributions to $(g-2)$ from vector boson and charged scalar loops respectively, the minimal scotogenic $L_{\mu }-L_{\tau }$ model can not explain muon and electron $(g-2)$ simultaneously while being consistent with other experimental bounds. We then extend the model with a vector like lepton doublet which not only leads to a chirally enhanced negative contribution to electron $(g-2)$ but also leads to the popular singlet-doublet fermion dark matter scenario. With this extension, the model can explain both electron and muon $(g-2)$ while being consistent with neutrino mass, dark matter and other direct search bounds. The model remains predictive at high energy experiments like collider as well as low energy experiments looking for charged lepton flavour violation, dark photon searches, in addition to future $(g-2)$ measurements.

   hep-phastro-ph.COhep-exPRD(2022)·55 citations
3. 03*

   Probing neutrino decay scenarios by using the Earth matter effects on supernova neutrinos

   Edwin A. Delgado🇺🇸 · Hiroshi Nunokawa🇧🇷 · Alexander A. Quiroga🇧🇷

   The observation of Earth matter effects in the spectrum of neutrinos coming from a next galactic core-collapse supernova (CCSN) could, in principle, reveal if neutrino mass ordering is normal or inverted. One of the possible ways to identify the mass ordering is through the observation of the modulations that appear in the spectrum when neutrinos travel through the Earth before they arrive at the detector. These features in the neutrino spectrum depend on two factors, the average neutrino energies, and the difference between the primary neutrino fluxes of electron and other flavors produced inside the supernova. However, recent studies indicate that the Earth matter effect for CCSN neutrinos is expected to be rather small and difficult to be observed by currently operating or planned neutrino detectors mainly because of the similarity of average energies and fluxes between electron and other flavors of neutrinos, unless the distance to CCSN is significantly smaller than the typically expected one, $\sim 10$ kpc. Here, we are looking towards the possibility if the non-standard neutrino properties such as decay of neutrinos can enhance the Earth matter effect. In this work we show that invisible neutrino decay can potentially enhance significantly the Earth matter effect for both ${\nu }_e$ and ${\bar{\nu }}_e$ channels at the same time for both mass orderings, even if the neutrino spectra between electron and other flavors of neutrinos are very similar, which is a different feature not expected for CCSN neutrinos with standard oscillation without the decay effect.

   hep-phastro-ph.HEJCAP(2022)·8 citations
4. 04*

   Two-to-two processes at an electron-muon collider

   Antonio O. Bouzas🇲🇽 · F. Larios🇲🇽

   Based on a recent proposal to build an electron-muon collider, we study two-to-two production processes e^- mu^+ --> f bar-f, gamma gamma that originate from dimension 6 and 8 operators. We compare the sensitivity to those effective couplings obtained at the collider with that of low energy measurements of mu --> e gamma, mu --> e bar-e e and mu --> e conversion that have recently been reported in the literature. Whereas for the production of first family fermions the sensitivity of the collider processes is much weaker, for the second and third family fermions it is similar or stronger than that of low-energy processes. In the case of e^- mu^+ --> gamma gamma, the sensitivity to a dimension 8 contact operator turns out to be the strongest in comparison.

   hep-phAdv.High Energy Phys.(2022)·8 citations
5. 05*

   Doubly heavy tetraquark states $cc\bar{u}\bar{d}$ and $bb\bar{u}\bar{d}$

   Xiaoyun Chen

   Inspired by the recent observation of a very narrow state, called $T_{cc}^{+}$, by the LHCb collaboration, the possible bound states and low-lying resonance states of the doubly heavy tetraquark states $cc\bar{u}\bar{d}$ ($T_{cc}$) and $bb\bar{u}\bar{d}$ ($T_{bb}$) are searched in the framework of chiral quark model with an accurate few body method, Gaussian expansion method. The real scaling method is also applied to identify the genuine resonance states. In the calculation, the meson-meson structure, diquark-antidiquark structure, as well as their coupling are all considered. The numerical results show that (i) for $T_{cc}$ and $T_{bb}$, only $I(J^P)=0(1^{+})$ states are bound in different quark structures. The binding energy varies from a few MeV for meson-meson structure to over 100 MeV for diquark-antidiquark structure. For example for $T_{cc}$, in meson-meson structure, there exists a weakly bound molecule $D{D}^{\ast }$ state around 3841.4 MeV, 1.8 MeV below the $D^0{D}^{\ast +}$, which may be a good candidate of the observed state by LHCb; however in diquark-antidiquark structure, a deeper bound sate with mass 3700.9 MeV is obtained; when considering the structure mixing, the energy of system decreases to 3660.7 MeV and the shallow bound state disappears. (ii) Besides bound states, several resonance states for $T_{QQ}(Q=c,b)$ with $I(J^P)=1(0^{+}),1(1^{+}),1(2^{+}),0(1^{+})$ are proposed.

   hep-phCPC(2022)·36 citations
6. 06*

   Two-flavor color superconductivity in the Fierz-transfromed Nambu--Jona-Lasinio model

   Wen-Hua Cai🇨🇳 · Qing-Wu Wang🇨🇳

   The color superconducting phase of two-flavor quark matter is studied under a Fierz-transformed Lagrangian. In the Fierz-transformed Lagrangian both the quark-antiquark and quark-quark channel are included. Two parameters $\alpha$ and $\beta$ are introduced to weight the Fierz-transformed quark-antiquark Lagrangian and quark-quark Lagrangian, respectively. The couplings of different interaction channel are thus fixed by the two coefficients other than five free parameters. The interplay between chiral symmetry restoration and the formation of color superconducting phases are discussed. It is found that the increase of $\alpha$ leads the chiral phase transition from first order to crossover. The calculated specific heat shows jump at critical temperature which confirms the phase transition. The increase of $\beta$ leads the pseudo-critical chemical potential reduce. With large $\beta$ the superconductors gap $\Delta$ can be larger than the typical value and the well-known BCS relation between critical temperature and gap is well fitted.

   hep-ph0 citations
7. 07*

   Radial excitation of light mesons and the $\gamma {\gamma }^{\ast }\to {\pi }^0$ transition form factor

   Fu-Guang Cao🇳🇿

   We investigate radial excitation of the quark-antiquark pair in the ${\pi }^0$ meson and its effects on the $\gamma {\gamma }^{\ast }\to {\pi }^0$ transition form factor in the framework of light-cone perturbative QCD. The existing constraints on the light-cone wave function of the lowest Fock state $|q\bar{q}⟩$ in the ${\pi }^0$ meson allow a sizeable radial excitation of the quark-antiquark pair. We construct the light-cone wave function for the quark-antiquark pair in the first radially excited state (the 2S state) using a simple harmonic oscillator potential. The distribution amplitude obtained for the 2S state has two nodes in $x$ at low scale of $Q$ and thereby has a much strong scale dependence than the 1S state. Contributions from this radial excitation to the $\gamma {\gamma }^{\ast }\to {\pi }^0$ transition form factor exhibit different $Q^2$-dependence behavior from the ground state and thus can modify the prediction for the transition form factor in the medium-large region of $Q^2$.

   hep-phPRD(2021)·2 citations
8. 08*

   Next-to-leading-order corrections to the Higgs strahlung process from electron-positron collisions in extended Higgs models

   Masashi Aiko🇯🇵 · Shinya Kanemura🇯🇵 · Kentarou Mawatari🇯🇵

   We present the cross section for $e^{+}{e}^{-}\to hZ$ with arbitrary sets of electron and $Z$ boson polarizations at the full next-to-leading order in various extended Higgs models, such as the Higgs singlet model (HSM), the inert doublet model (IDM) and the two Higgs doublet model (2HDM). We systematically perform complete one-loop calculations to the helicity amplitudes in the on-shell renormalization scheme, and present the full analytic results as well as numerical evaluations. The deviation $\Delta R^{hZ}$ in the total cross section from its standard model (SM) prediction is comprehensively analyzed, and the differences among these models are discussed in details. We find that new physics effects appearing in the renormalized $hZZ$ vertex almost govern the behavior of $\Delta R^{hZ}$, and it takes a negative value in most cases. The possible size of $\Delta R^{hZ}$ reaches several percent under the theoretical and experimental bounds. We also analyze the deviation $\Delta R_{XY}^{hZ}$ in the total cross section times decay branching ratios of the discovered Higgs boson by utilizing the $\text{H-COUP}$ program. It is found that the four types of 2HDMs can be discriminated by analyzing the correlation between $\Delta R_{\tau \tau }^{hZ}$ and $\Delta R_{bb}^{hZ}$ and those between $\Delta R_{\tau \tau }^{hZ}$ and $\Delta R_{cc}^{hZ}$. Furthermore, the HSM and the IDM can be discriminated from the 2HDMs by measuring $\Delta R_{WW}^{hZ}$. These signatures can be tested by precision measurements at future Higgs factories such as the International Linear Collider.

   hep-phhep-exEPJC(2021)·13 citations
9. 09*

   Baryonic $B$ meson decays

   Xiaotao Huang🇨🇳 · Yu-Kuo Hsiao🇨🇳 · Jike Wang🇨🇳 · Liang Sun🇨🇳

   We review the two and three-body baryonic $B$ decays with the dibaryon ($\mathbf{B}{\bar{\mathbf{B}}}^{\prime }$) as the final states. Accordingly, we summarize the experimental data of the branching fractions, angular asymmetries, and $CP$ asymmetries. Using the $W$-boson annihilation (exchange) mechanism, the branching fractions of $B\to \mathbf{B}{\bar{\mathbf{B}}}^{\prime }$ are shown to be interpretable. In the approach of perturbative QCD counting rules, we study the three-body decay channels. In particular, we review the $CP$ asymmetries of $B\to \mathbf{B}{\bar{\mathbf{B}}}^{\prime }M$, which are promising to be measured by the LHCb and Belle~II experiments. Finally, we remark the theoretical challenges in interpreting $\mathcal{B}(B^{-}\to p\bar{p}{\rho }^{-})$ and $\mathcal{B}(B^{-}\to p\bar{p}{\mu }^{-}{\bar{\nu }}_{\mu })$.

   hep-phhep-exAdv.High Energy Phys.(2022)·15 citations
10. 10*

    Unstable Cosmic Neutrino Capture

    Kensuke Akita🇰🇷 · Gaetano Lambiase🇮🇹 · Masahide Yamaguchi🇯🇵

    Future direct observations of the Cosmic Neutrino Background (C$\nu$B) have the potential to explore a neutrino lifetime, especially in the region of the age of the universe, $t_0=4.35\times 10^{17}\mathrm{s}$. We forecast constraints on neutrino decay via capture of the C$\nu$B on tritium, with emphasis on the PTOLEMY-type experiment. In addition, in some cases of invisible neutrino decay into lighter neutrinos in the Standard Model and invisible particles, we can constrain not only the neutrino lifetime but also the masses of the invisible particles. For this purpose, we also formulate the energy spectra of the lighter neutrinos produced by 2-body and 3-body decays, and those of the electrons emitted in the process of the detection of the lighter neutrinos.

    hep-phastro-ph.COhep-exJHEP(2022)·19 citations
11. 11*

    Sensitivity to BSM effects in the Higgs $p_T$ spectrum within SMEFT

    Marco Battaglia🇺🇸 · Massimiliano Grazzini🇨🇭 · Michael Spira🇨🇭 · Marius Wiesemann🇩🇪

    The study of Higgs boson production at large transverse momentum is one of the new frontiers for the LHC Higgs physics programme. This paper considers boosted Higgs production in the Standard Model Effective Field Theory (SMEFT). We focus on the gluon fusion and $t\bar{t}H$ production processes and study the effects of three dimension-6 operators: the top Yukawa operator, the gluon-Higgs effective coupling and the chromomagnetic dipole operator of the top quark. We perform a detailed study of the sensitivity of current and future LHC data to the corresponding Wilson coefficients, consistently accounting for their renormalisation group evolution. We compare the sensitivities obtained with only linear and linear + quadratic terms in the SMEFT by using the spectrum shape and the addition of the Higgs signal yields. We also consider fits of $p_T$ spectra in models with heavy-top partners and in MSSM scenarios with a light scalar top and study the validity of the SMEFT assumptions as a function of the new-particle masses and the Higgs $p_T$ range. Finally, we extract constraints on the Wilson coefficients for gluon fusion from a simultaneous fit to the ATLAS and CMS data and compare our results with those obtained in global SMEFT analyses.

    hep-phhep-exJHEP(2021)·48 citations
12. 12*

    Generalized Vector Dominance Model up to 2 GeV

    N.N. Achasov🇷🇺 · A.V. Kiselev🇷🇺 · A.A. Kozhevnikov🇷🇺

    The processes $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-},\omega {\pi }^0,\eta {\pi }^{+}{\pi }^{-},K^{+}{K}^{-},{\pi }^{+}{\pi }^{-}{\pi }^0$ are described simultaneously in the frame of the Generalized Vector Dominance Model (GVDM) allowing model error. The data do not contradict the assumption that the precision of the model we use is not worse than 6\%. This shows that GVDM is an adequate approach to describe processes involving $\rho (770),\omega (787),\varphi (1020)$ and their excitations in the energy region below 2 GeV. This work is considered as a first step, next steps should treat more processes and take into account finer effects.

    hep-phhep-ex0 citations
13. 13*

    From semi-hard processes to the unintegrated gluon distribution: a phenomenological path in the high-energy framework

    Andrèe Dafne Bolognino🇮🇹

    The class of semi-hard reactions represents a promising venue where to enhance our knowledge of strong interactions and deepen the aspects related to this theory in kinematical regimes so far unexplored. In particular, the high energies reached in electron-proton and in proton-proton collisions first at HERA and then at the LHC, allow us to study scattering amplitudes of hard and semi-hard processes in perturbative QCD. The structure of this thesis can be considered twofold. On one hand, the possibility to distinguish those channels where at least two final-state particles are emitted with large separation in rapidity and with an untagged system, permits to test the BFKL dynamics as resummation energy logarithms in the $t$-channel. In the BFKL formalism, the Mueller--Navelet jets process has been one of the most investigated reactions. With the idea of deepening our understanding of the BFKL approach, a new channel is proposed: the inclusive production of a light charged hadron and a jet with high transverse momentum widely separated in rapidity. The importance of this process relies in the possibility to probe a complementary region to one analyzed for the Mueller--Navelet jets. Additionally, another reaction is proposed: the heavy-quark pairs hadroproduction. On the other hand, also the class of processes featured by the detection of a single forward object in lepton-proton collision offers the opportunity to develop intriguing phenomenological studies. In particular, the exclusive leptoproduction of light vector mesons, $\rho$ and $\varphi$, is exhaustively investigated. In this context, the study of helicity-dependent observables allows us to discriminate among several unintegrated gluon distribution models, whose original definition naturally encodes the BFKL-equation evolution dynamics. This kind of parton density allows us to get access to the hadronic structure at small-$x$.

    hep-ph13 citations
14. 14*

    Holographic charm and bottom pentaquarks III: Excitations through photo-production of heavy mesons

    Yizhuang Liu🇵🇱 · Kiminad A. Mamo🇺🇸 · Maciej A. Nowak🇵🇱 · Ismail Zahed🇺🇸

    We consider the photo-excitation of charm and bottom pentaquarks with the holographic assignments $[\frac{1}{2}{\frac{1}{2}}^{-}{]}_{S=0,1}$ and $[\frac{1}{2}{\frac{3}{2}}^{-}{]}_{S=1}$, in the photo-production of heavy vector mesons such as charmonia and bottomonia near threshold. We use a Witten diagram to combine the s-channel photo-excitation of holographic pentaquarks with a massive t-channel graviton or tensor glueball exchange, to extract the scattering amplitude for heavy meson photo-production in the threshold region. The pentaquark signal is too weak to be detected at current electron facilities.

    hep-phhep-thnucl-exnucl-thPRD(2021)·10 citations
15. 15*

    Searches for new interactions within the SMEFT framework at present and future colliders

    Luca Mantani🇧🇪

    The existence of Beyond Standard Model (BSM) physics is firmly suggested by both experimental observations (Dark Matter, neutrino masses) and theoretical arguments. In the hypothesis that the scale of new physics is considerably higher than the energies probed at colliders, we can parametrise modified interactions induced by BSM effects among SM particles in a model-independent framework, the Standard Model Effective Field Theory (SMEFT). Searches for indirect evidence of new physics are conceptually different from the direct ones that have characterised the first part of the LHC program, and both experimental and phenomenological studies are needed in order to maximise the chances of uncovering a BSM signal. In this thesis, several phenomenological aspects of the SMEFT are discussed, both at present and future colliders. A characteristic feature of modified interactions is that they can induce unitarity violating effects which can be exploited to gain sensitivity. In this direction, a thorough study of the top quark electroweak sector will be presented, focusing on 2 to 2 scatterings and their embeddings in physical processes at colliders. This analysis allows us to identify several final states that have a good potential to explore the SMEFT parameter space and that could be particularly relevant in a global analysis. One of the key features of the SMEFT is indeed that deviations from the SM interactions are correlated and global interpretations are therefore of fundamental importance. A combined interpretation of the Higgs, top and diboson data from the LHC is here presented and the interplay between the various datasets discussed. Finally, the physics potential of a futuristic muon collider will be analysed, focusing in particular on the prospects to determine the Higgs self-interactions, a task that is arduous even in proposed 100 TeV proton colliders.

    hep-ph0 citations
16. 16*

    SU(3) flavor symmetry considerations for the $\bar{K}N$ coupled channels system

    P. C. Bruns🇨🇿 · A. Cieplý🇨🇿

    We study the impact of SU(3) flavor symmetry breaking on the properties of dynamically generated ${\Lambda }^{\ast }$ states within an effective separable potential model describing the coupled channels $\bar{K}N$ system. The model is based on the chiral meson-baryon Lagrangian at next-to-leading order, and constitutes an improvement over a previous model developed by our group, with its applicability being extended to higher energies covering the $\Lambda (1670)$ resonance region. It is demonstrated that the ratios of channel couplings to the resonant states can vary dramatically when the flavor breaking is gradually switched off, tracing a path to the restored SU(3) symmetry. We conclude that the couplings determined from physical observables cannot be used to reliably relate a given resonance to a specific flavor multiplet.

    hep-phnucl-thNPA(2022)·20 citations
17. 17*

    Fog on the horizon: a new definition of the neutrino floor for direct dark matter searches

    Ciaran A. J. O'Hare🇦🇺

    The neutrino floor is a theoretical lower limit on WIMP-like dark matter models that are discoverable in direct detection experiments. It is commonly interpreted as the point at which dark matter signals become hidden underneath a remarkably similar-looking background from neutrinos. However, it has been known for some time that the neutrino floor is not a hard limit, but can be pushed past with sufficient statistics. As a consequence, some have recently advocated for calling it the "neutrino fog" instead. The downside of current methods of deriving the neutrino floor are that they rely on arbitrary choices of experimental exposure and energy threshold. Here we propose to define the neutrino floor as the boundary of the neutrino fog, and develop a calculation free from these assumptions. The technique is based on the derivative of a hypothetical experimental discovery limit as a function of exposure, and leads to a neutrino floor that is only influenced by the systematic uncertainties on the neutrino flux normalisations. Our floor is broadly similar to those found in the literature, but differs by almost an order of magnitude in the sub-GeV range, and above 20~GeV.

    hep-phastro-ph.COhep-exPRL(2021)·342 citations
18. 18*

    A Sub-GeV Low Mass Hidden Dark Sector of $SU(2{)}_H\times U(1{)}_X$

    Raymundo Ramos🇹🇼 · Van Que Tran🇨🇳 · Tzu-Chiang Yuan🇹🇼

    We present a detailed study of the non-abelian vector dark matter candidate $W^{\prime }$ with a MeV-GeV low mass range, accompanied by a dark photon $A^{\prime }$ and a dark $Z^{\prime }$ of similar masses, in the context of a gauged two-Higgs-doublet model with the hidden gauge group that has the same structure as the Standard Model electroweak gauge group. The stability of dark matter is protected by an accidental discrete $Z_2$ symmetry ($h$-parity) which was usually imposed ad hoc by hand. We examine the model by taking into account various experimental constraints including dark photon searches at NA48, NA64, E141, $\nu$-CAL, BaBar and LHCb experiments, electroweak precision data from LEP, relic density from Planck satellite, direct (indirect) detection of dark matter from CRESST-III, DarkSide-50, XENON1T (Fermi-LAT), and collider physics from the LHC. The theoretical requirements of bounded from below of the scalar potential and tree level perturbative unitarity of the scalar sector are also imposed. The viable parameter space of the model consistent with all the constraints is exhibited. While a dark $Z^{\prime }$ can be the dominant contribution in the relic density due to resonant annihilation of dark matter, a dark photon is crucial to dark matter direct detection. We also demonstrate that the parameter space can be further probed by various sub-GeV direct dark matter experimental searches at CDEX, NEWS-G and SuperCDMS in the near future.

    hep-phJHEP(2021)·11 citations
19. 19*

    Muonic Boson Limits: Supernova Redux

    Andrea Caputo🇮🇱 · Georg Raffelt🇩🇪 · Edoardo Vitagliano🇺🇸

    We derive supernova (SN) bounds on muon-philic bosons, taking advantage of the recent emergence of muonic SN models. Our main innovations are to consider scalars $\varphi$ in addition to pseudoscalars $a$ and to include systematically the generic two-photon coupling $G_{\gamma \gamma }$ implied by a muon triangle loop. This interaction allows for Primakoff scattering and radiative boson decays. The globular-cluster bound $G_{\gamma \gamma }<0.67\times 10^{-10}{\mathrm{GeV}}^{-1}$ derived for axion-like particles carries over to the muonic Yukawa couplings as $g_a<3.1\times 10^{-9}$ and $g_{\varphi }<4.6\times 10^{-9}$ for $m_{a,\varphi }\lesssim 100$ keV, so SN arguments become interesting mainly for larger masses. If bosons escape freely from the SN core the main constraints originate from SN1987A $\gamma$ rays and the diffuse cosmic $\gamma$-ray background. The latter allows at most $10^{-4}$ of a typical total SN energy of $E_{\mathrm{SN}}\simeq 3\times 10^{53}$erg to show up as $\gamma$ rays, for $m_{a,\varphi }\gtrsim 100$keV implying $g_a\lesssim 0.9\times 10^{-10}$ and $g_{\varphi }\lesssim 0.4\times 10^{-10}$. In the trapping regime the bosons emerge as quasi-thermal radiation from a region near the neutrino sphere and match $L_{\nu }$ for $g_{a,\varphi }\simeq 10^{-4}$. However, the $2\gamma$ decay is so fast that all the energy is dumped into the surrounding progenitor-star matter, whereas at most $10^{-2}{E}_{\mathrm{SN}}$ may show up in the explosion. To suppress boson emission below this level we need yet larger couplings, $g_a\gtrsim 2\times 10^{-3}$ and $g_{\varphi }\gtrsim 4\times 10^{-3}$. Muonic scalars can explain the muon magnetic-moment anomaly for $g_{\varphi }\simeq 0.4\times 10^{-3}$, a value hard to reconcile with SN physics despite the uncertainty of the explosion-energy bound. For generic axion-like particles, this argument covers the "cosmological triangle" in the $G_{a\gamma \gamma }$--$m_a$ parameter space.

    hep-phastro-ph.COastro-ph.HEhep-exPRD(2022)·239 citations
20. 20*

    Joint CMB and BBN Constraints on Light Dark Sectors with Dark Radiation

    Cara Giovanetti🇺🇸 · Mariangela Lisanti🇺🇸 · Hongwan Liu🇺🇸 · Joshua T. Ruderman🇺🇸

    Dark sectors provide a compelling theoretical framework for thermally producing sub-GeV dark matter, and motivate an expansive new accelerator and direct-detection experimental program. We demonstrate the power of constraining such dark sectors using the measured effective number of neutrino species, $N_{\text{eff}}$, from the Cosmic Microwave Background (CMB) and primordial elemental abundances from Big Bang Nucleosynthesis (BBN). As a concrete example, we consider a dark matter particle of arbitrary spin that interacts with the Standard Model via a massive dark photon, accounting for an arbitrary number of light degrees of freedom in the dark sector. We exclude dark matter masses below $\sim$ 4 MeV at 95% confidence for all dark matter spins and dark photon masses. These bounds hold regardless of additional new light, inert degrees of freedom in the dark sector, and for dark matter-electron scattering cross sections many orders of magnitude below current experimental constraints. The strength of these constraints will only continue to improve with future CMB experiments.

    hep-phastro-ph.COPRL(2022)·87 citations
21. 21*

    Impact of COHERENT measurements, cross section uncertainties and new interactions on the neutrino floor

    D. Aristizabal Sierra🇨🇱 · V. De Romeri🇪🇸 · L. J. Flores🇲🇽 · D. K. Papoulias🇬🇷

    We reconsider the discovery limit of multi-ton direct detection dark matter experiments in the light of recent measurements of the coherent elastic neutrino-nucleus scattering process. Assuming the cross section to be a parameter entirely determined by data, rather than using its Standard Model prediction, we use the COHERENT CsI and LAr data sets to determine WIMP discovery limits. Being based on a data-driven approach, the results are thus free from theoretical assumptions and fall within the WIMP mass regions where XENONnT and DARWIN have best expected sensitivities. We further determine the impact of subleading nuclear form factor and weak mixing angle uncertainties effects on WIMP discovery limits. We point out that these effects, albeit small, should be taken into account. Moreover, to quantify the impact of new physics effects in the neutrino background, we revisit WIMP discovery limits assuming light vector and scalar mediators as well as neutrino magnetic moments/transitions. We stress that the presence of new interactions in the neutrino sector, in general, tend to worsen the WIMP discovery limit.

    hep-phJCAP(2022)·45 citations
22. 22*

    Twin Quark Dark Matter From Cogenesis

    Can Kilic🇺🇸 · Christopher B. Verhaaren🇺🇸 · Taewook Youn🇺🇸

    We extend the fraternal twin Higgs scenario to include a novel dark matter candidate as well as a mechanism for generating a matter/antimatter asymmetry in both sectors. A spontaneous breaking of twin color results in quark degrees of freedom that are singlets under the residual twin color group. These twin-color-singlet quarks, along with a subdominant component of twin leptons, constitute the asymmetric dark matter. The asymmetry between matter in antimatter in both sectors is co-generated from the decay of singlet fermions that provide an additional portal between the visible and twin sectors. We discuss the phenomenological aspects of this model, evaluating constraints on the parameter space and highlighting promising discovery channels in future experiments. We briefly discuss how the discovery of signals in multiple experiments may help establish the connection between the mechanisms that address the naturalness, dark matter and matter/antimatter asymmetry puzzles.

    hep-phPRD(2021)·20 citations
23. 23*

    Mass Composition of UHECRs from $X_{\max }$ Distributions Recorded by the Pierre Auger and Telescope Array Observatories

    Nicusor Arsene🇷🇴

    In this paper we infer the mass composition of the ultra high energy cosmic rays (UHECRs) from measurements of $X_{\max }$ distributions recorded at the Pierre Auger (2014) and Telescope Array (TA) (2016) Observatories, by fitting them with all possible combinations of Monte Carlo (MC) templates from a large set of primary species (p, He, C, N, O, Ne, Si and Fe), as predicted by EPOS-LHC, QGSJETII-04 and Sibyll 2.1 hadronic interaction models. We use the individual fractions of nuclei reconstructed from one experiment in each energy interval to build equivalent MC $X_{\max }$ distributions, which we compare with the experimental $X_{\max }$ distributions of the other experiment, applying different statistical tests of compatibility. The results obtained from both experiments confirm that the mass composition of the UHECRs is dominated ($\gtrsim$$70\%$) by protons and He nuclei {in the energy range investigated $\lg E(\mathrm{eV})$ = [17.8--19.3] (Auger) and $\lg E(\mathrm{eV})$ = [18.2--19.0] (TA).} The indirect comparisons between the $X_{\max }$ distributions recorded by the two experiments show that the degree of compatibility of the two datasets is good, even excellent in some high energy intervals, especially above the ankle ($\lg E(\mathrm{eV})\sim 18.7$). However, our study reveals that, at low energies, further effort in data analysis is required in order to harmonize the results of the two experiments.

    hep-phastro-ph.HEUniverse(2021)·11 citations
24. 24*

    Scattering searches for dark matter in subhalos: neutron stars, cosmic rays, and old rocks

    Joseph Bramante🇨🇦 · Bradley J. Kavanagh🇪🇸 · Nirmal Raj🇨🇦

    In many cosmologies dark matter clusters on sub-kiloparsec scales and forms compact subhalos, in which the majority of Galactic dark matter could reside. Null results in direct detection experiments since their advent four decades ago could then be the result of extremely rare encounters between the Earth and these subhalos. We investigate alternative and promising means to identify subhalo dark matter interacting with Standard Model particles: (1) subhalo collisions with old neutron stars can transfer kinetic energy and brighten the latter to luminosities within the reach of imminent infrared, optical, and ultraviolet telescopes; we identify new detection strategies involving single-star measurements and Galactic disk surveys, and obtain the first bounds on self-interacting dark matter in subhalos from the coldest known pulsar, PSR J2144-3933, (2) subhalo dark matter scattering with cosmic rays results in detectable effects, (3) historic Earth-subhalo encounters can leave dark matter tracks in paleolithic minerals deep underground. These searches could discover dark matter subhalos weighing between gigaton and solar masses, with corresponding dark matter cross sections and masses spanning tens of orders of magnitude.

    hep-phastro-ph.COastro-ph.HEhep-exPRL(2022)·62 citations
25. 25*

    Testing the Early Universe with Anisotropies of the Gravitational Wave Background

    Ema Dimastrogiovanni🇳🇱 · Matteo Fasiello🇪🇸 · Ameek Malhotra🇦🇺 · P. Daniel Meerburg🇳🇱 · Giorgio Orlando🇳🇱

    In this work we analyse in detail the possibility of using small and intermediate-scale gravitational wave anisotropies to constrain the inflationary particle content. First, we develop a phenomenological approach focusing on anisotropies generated by primordial tensor-tensor-scalar and purely gravitational non-Gaussianities. We highlight the quantities that play a key role in determining the detectability of the signal. To amplify the power of anisotropies as a probe of early universe physics, we consider cross-correlations with CMB temperature anisotropies. We assess the size of the signal from inflationary interactions against so-called induced anisotropies. In order to arrive at realistic estimates, we obtain the projected constraints on the non-linear primordial parameter $F_{\mathrm{NL}}$ for several upcoming gravitational wave probes in the presence of the astrophysical gravitational wave background. We further illustrate our findings by considering a concrete inflationary realisation and use it to underscore a few subtleties in the phenomenological analysis.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2022)·44 citations
26. 26*

    Lensing of gravitational waves as a probe of compact dark matter

    Juan Urrutia🇪🇸 · Ville Vaskonen🇪🇸

    We study gravitational lensing of gravitational waves from compact object binaries as a probe of compact dark matter (DM) objects such as primordial black holes. Assuming a point mass lens, we perform parameter estimation of lensed gravitational wave signals from compact object binaries to determine the detectability of the lens with ground based laser interferometers. Then, considering binary populations that LIGO-Virgo has been probing, we derive a constraint on the abundance of compact DM from non-observation of lensed events. We find that the LIGO-Virgo observations imply that compact objects heavier than $M_l=200M_{\odot }$ can not constitute all DM and less than $40\%$ of DM can be in compact objects heavier than $M_l=400M_{\odot }$. We also show that the DM fraction in compact objects can be probed by LIGO in its final sensitivity for $M_l>40M_{\odot }$ reaching $2\%$ of the DM abundance at $M_l>200M_{\odot }$, and by ET for $M_l>1M_{\odot }$ reaching DM fraction as low as $7\times 10^{-5}$ at $M_l>40M_{\odot }$.

    ↳ astro-ph.COastro-ph.HEhep-phMNRAS(2021)·84 citations
27. 27*

    Multiple point criticality principle and Coleman-Weinberg inflation

    Antonio Racioppi🇪🇪 · Jürgen Rajasalu🇪🇪 · Kaspar Selke🇪🇪

    We apply the multiple point criticality principle to inflationary model building and study Coleman-Weinberg inflation when the scalar potential is quadratic in the logarithmic correction. We analyze also the impact of a non-minimal coupling to gravity under two possible gravity formulation: metric or Palatini. We compare the eventual compatibility of the results with the final data release of the Planck mission.

    ↳ astro-ph.COgr-qchep-phJHEP(2022)·28 citations
28. 28*

    Dark Matter Microhalos in the Solar Neighborhood: Pulsar Timing Signatures of Early Matter Domination

    M. Sten Delos🇩🇪 · Tim Linden🇸🇪

    Pulsar timing provides a sensitive probe of small-scale structure. Gravitational perturbations arising from an inhomogeneous environment could manifest as detectable perturbations in the pulsation phase. Consequently, pulsar timing arrays have been proposed as a probe of dark matter substructure on mass scales as small as $10^{-11}{M}_{\odot }$. Since the small-scale mass distribution is connected to early-Universe physics, pulsar timing can therefore constrain the thermal history prior to Big Bang nucleosynthesis (BBN), a period that remains largely unprobed. We explore here the prospects for pulsar timing arrays to detect the dark substructure imprinted by a period of early matter domination (EMD) prior to BBN. EMD amplifies density variations, leading to a population of highly dense sub-Earth-mass dark matter microhalos. We use recently developed semianalytic models to characterize the distribution of EMD-induced microhalos, and we evaluate the extent to which the pulsar timing distortions caused by these microhalos can be detected. Broadly, we find that sub-0.1-$\mu$s timing noise residuals are necessary to probe EMD. However, with 10-ns residuals, a pulsar timing array with just 70 pulsars could detect the evidence of an EMD epoch with 20 years of observation time if the reheat temperature is of order 10 MeV. With 40 years of observation time, pulsar timing arrays could probe EMD reheat temperatures as high as 150 MeV.

    ↳ astro-ph.COastro-ph.HEhep-phPRD(2022)·25 citations
29. 29*

    Hybrid inflation and waterfall field in string theory from D7-branes

    Ignatios Antoniadis🇫🇷 · Osmin Lacombe🇫🇷 · George K. Leontaris🇬🇷

    We present an explicit string realisation of a cosmological inflationary scenario we proposed recently within the framework of type IIB flux compactifications in the presence of three magnetised D7-brane stacks. Inflation takes place around a metastable de Sitter vacuum. The inflaton is identified with the volume modulus and has a potential with a very shallow minimum near the maximum. Inflation ends due to the presence of "waterfall" fields that drive the evolution of the Universe from a nearby saddle point towards a global minimum with tuneable vacuum energy describing the present state of our Universe.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2022)·20 citations
30. 30*

    New Anomalies, TQFTs, and Confinement in Bosonic Chiral Gauge Theories

    Mohamed M. Anber🇺🇸 · Sungwoo Hong🇺🇸 · Minho Son🇰🇷

    We study a class of 4-dimensional $SU(N)$ chiral gauge theories with fermions in the 2-index symmetric and antisymmetric representations and classify their infrared phases. The choice $N=4\mathbb{Z}$ corresponds to gauging the fermion number and makes the theory purely bosonic. We examine the most general background fields of the centers of the gauge, non-abelian flavor, and $U(1)$-axial groups that can be consistently activated, thereby determine the faithful global continuous and discrete symmetries of the theory. This allows us to identify new mixed 0-form/1-form `t Hooft anomalies on both spin and nonspin manifolds. If the theory confines, the absence of composite fermions implies that continuous symmetries must be broken down to anomaly-free subgroups. Anomalies associated with discrete symmetries can be saturated either by breaking the symmetry or by a symmetry-preserving topological quantum field theory (TQFT). The latter, however, is obstructed on spin manifold. The interplay between these features greatly restricts the possible infrared physics. We present two examples that demonstrate our approach. We argue that if the theory confines, the zoo of anomalies and TQFT obstruction greatly restrict the viable infrared condensates. We also discuss the possibility that some theories flow to a conformal fixed point.

    ↳ hep-thhep-phJHEP(2022)·34 citations
31. 31*

    Lorentz violation in the matter-gravity sector

    Zonghao Li🇺🇸

    We construct the general Lorentz-violating effective field theory in curved spacetime and the corresponding nonrelativistic Hamiltonian in the Earth's gravitational field. Applying this general framework to three types of experiments, free-dropping, interferometer, and bound-state experiments, we extract first constraints on certain new coefficients in the matter-gravity sector.

    ↳ gr-qchep-ph0 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.