Mon·May 8, 2023Monday·May 8, 2023

1. 01*

   Hunting muonic forces at emulsion detectors

   Akitaka Ariga🇨🇭 · Reuven Balkin🇮🇱 · Iftah Galon🇮🇱 · Enrique Kajomovitz🇮🇱 · Yotam Soreq🇮🇱

   Only two types of Standard Model particles are able to propagate the $480$meters separating the ATLAS interaction point and FASER: neutrinos and muons. Furthermore, muons are copiously produced in proton collisions. We propose to use FASER$\nu$ as a muon fixed target experiment in order to search for new bosonic degrees of freedom coupled predominantly to muons. These muon force carriers are particularly interesting in light of the recent measurement of the muon anomalous magnetic moment. Using a novel analysis technique, we show that even in the current LHC run, FASER$\nu$ could potentially probe previously unexplored parts of the parameter space. In the high-luminosity phase of the LHC, we find that the improved sensitivity of FASER$\nu 2$ will probe unexplored parameter space and may be competitive with dedicated search proposals.

   hep-phPRD(2024)·24 citations
2. 02*

   Impact of Simultaneous Stellar Modeling Uncertainties on the Tip of the Red Giant Branch for Axion-Election Coupling

   Mitchell T. Dennis🇺🇸 · Jeremy Sakstein🇺🇸

   We present a novel method for incorporating the effects of stellar modeling uncertainties into constraints on the axion-electron coupling constant found using the observed calibration of the tip of the red giant branch (TRGB) I band magnitude $M_I$.~We simulate grids of models with varying initial stellar mass, helium abundance, metallicity, and axion-electron coupling ${\alpha }_{26}=10^{26}{g}_{ae}^2/4\pi$ but different (fixed) mixing lengths and mass loss efficiencies.~We then train separate machine learning emulators to predict $M_I$ as a function of the varying parameters for each grid.~Our emulators enable the use of Markov Chain Monte Carlo simulations where ${\alpha }_{26}$ is varied simultaneously with the stellar parameters.~One of our grids yields a bound ${\alpha }_{26}\le 0.75$ at the 95\% confidence limit, a factor of $\sim 3.7$ weaker than previous bounds;~while the other grid yields ${\alpha }_{26}\le 1.58$ at the 95\% confidence limit, a factor $\sim 7.8$ weaker than previous bounds.~We demonstrate that the different values we find are due to covariances between stellar and axion physics that are not accounted for by single parameter variations.~Our results suggest that the bound on ${\alpha }_{26}$ derived using empirical calibrations of the TRGB I band magnitude need to be reevaluated using simultaneous parameter variation.~Alternative methods that use the bolometric luminosity instead of $M_I$ are more robust because they are not reliant upon theoretical predictions of the effective temperature.

   hep-phastro-ph.COastro-ph.SRgr-qcPhys.Dark Univ.(2025)·13 citations
3. 03*

   FIMP Dark Matter from Flavon Portals

   K.S. Babu🇺🇸 · Shreyashi Chakdar🇺🇸 · Nandini Das🇮🇳 · Dilip Kumar Ghosh🇮🇳 · Purusottam Ghosh🇮🇳

   We investigate the phenomenology of a non-thermal dark matter (DM) candidate in the context of flavor models that explain the hierarchy in the masses and mixings of quarks and leptons via the Froggatt-Nielsen (FN) mechanism. A flavor-dependent $U(1{)}_{\mathrm{FN}}$ symmetry explains the fermion mass and mixing hierarchy, and also provides a mechanism for suppressed interactions of the DM, assumed to be a Majorana fermion, with the Standard Model (SM) particles, resulting in its FIMP (feebly interacting massive particle) character. Such feeble interactions are mediated by a flavon field through higher dimensional operators governed by the $U(1{)}_{\mathrm{FN}}$ charges. We point out a natural stabilizing mechanism for the DM within this framework with the choice of half-integer $U(1{)}_{\mathrm{FN}}$ charge $n$ for the DM fermion, along with integer charges for the SM fermions and the flavon field. In this flavon portal scenario, the DM is non-thermally produced from the decay of the flavon in the early universe which becomes a relic through the freeze-in mechanism. We explore the allowed parameter space for this DM candidate from relic abundance by solving the relevant Boltzmann equations. We find that reproducing the correct relic density requires the DM mass to be in the range $(100-300)$ keV for $n=7.5$ and $(3-10)$ MeV for $n=8.5$ where $n$ is the $U(1{)}_{\mathrm{FN}}$ charge of the DM fermion.

   hep-phJHEP(2023)·8 citations
4. 04*

   Cosmic rays from heavy particle decays

   E.V. Arbuzova🇷🇺 · A.D. Dolgov🇷🇺 · A.A. Nikitenko🇷🇺

   Multidimensional modification of gravity with a smaller mass scale of the gravitational interaction is considered. Stable by assumption dark matter particles could decay via interactions with virtual black holes. The decay rates of such processes are estimated. It is shown that with the proper fixation of the parameters the decays of these ultra-massive particles can give noticeable contribution to the flux of high energy cosmic rays in particular, near the Greisen-Zatsepin-Kuzmin limit. Such particles can also create neutrinos of very high energies observed in the existing huge underwater or ice-cube detectors.

   hep-phastro-ph.HEgr-qcPhys.Atom.Nucl.(2024)·5 citations
5. 05*

   COHERENT production of a dark fermion

   Pablo M. Candela🇪🇸 · Valentina De Romeri🇪🇸 · Dimitrios K. Papoulias🇬🇷

   We consider the possible production of a new MeV-scale fermion at the COHERENT experiment. The new fermion, belonging to a dark sector, can be produced through the up-scattering process of neutrinos off the nuclei and the electrons of the detector material, via the exchange of a light vector or scalar mediator. We perform a detailed statistical analysis of the combined COHERENT CsI and LAr data sets and obtain up-to-date constraints on the couplings and masses of the dark fermion and mediators. We finally briefly comment about the stability of the dark fermion.

   hep-phPRD(2023)·18 citations
6. 06*

   Flavor Exotic Triply-Heavy Tetraquark States in AdS/QCD Potential

   Halil Mutuk🇹🇷

   We study the $S$-wave mass spectra of flavor exotic triply-heavy tetraquark states $cc\bar{c}\bar{q}$, $cc\bar{b}\bar{q}$, $bb\bar{c}\bar{q}$ and $bb\bar{b}\bar{q}$. We adopt a diquark-antidiquark scheme to solve Schrödinger equation. The calculations are carried out in a nonrelativistic quark model with a color interaction described by a potential computed in AdS/QCD. The AdS/QCD potential model consists of a central potential which reflects short distance and large distance behaviour of QCD, spin dependent term for hyperfine splitting and a constant term. We find stable state candidates in the $cc\bar{c}\bar{q}$ sector whereas in the $cc\bar{b}\bar{q}$, $bb\bar{c}\bar{q}$ and $bb\bar{b}\bar{q}$ sectors all the states lie above corresponding $S$-wave meson-meson thresholds. \end{abstract}

   hep-phEPJC(2023)·16 citations
7. 07*

   A multi-channel U-Matrix model of hadron interaction at high energy

   Rami Oueslati🇧🇪

   The present phenomenological study investigates a multi-channel model of high-energy hadron interactions by considering a full parton configurations space and the $U$-matrix unitarisation scheme of the elastic amplitude, comparing it to the two-channel model, and examining the consequences of up-to-date high-energy collider data on the best fits to various hadronic observables in $pp$ and $p\bar{p}$ collisions. The findings of this study reveal that the data are well-fitted with the multi-channel model and that the difference compared to the two-channel one is negligible. Of particular significance is the observation that the $U$-matrix unitarisation is likely incompatible with uncorrelated pomeron exchange, as suggested by the equivalence between the $U$-matrix multi-channel and eikonal two-channel descriptions. Based on our best fit, predictions for the $\rho$ parameter, the double diffractive cross-section, and the elastic differential cross-section are provided. We shed light on the effect of taking into account a multi-channel model on present and future cosmic ray data.

   hep-phJHEP(2023)·3 citations
8. 08*

   Impact of the $f$-Reggeon exchanges on the observables of the single diffractive dissociation of nucleon at ultrahigh energies

   A.A. Godizov🇷🇺

   Single diffractive dissociation (SDD) of nucleon in high-energy proton-proton and proton-antiproton collisions is considered in terms of a simple two-Reggeon model with nonlinear Regge trajectories. It is demonstrated that the $f$-Reggeon impact on the corresponding cross-sections is not negligible up to the LHC energies. As well, it is shown that the account of the $f$-Reggeon exchanges allows to describe the elastic diffractive scattering (EDS) and SDD of nucleons at ultrahigh energies in the framework of a unified phenomenological scheme. The predictive value of the proposed model is verified.

   hep-phhep-exEPJC(2024)·0 citations
9. 09*

   Detecting ALP wiggles at TeV energies

   M. Kachelriess🇳🇴 · J. Tjemsland🇳🇴

   Axions and axion-like-particles (ALPs) are characterised by their two-photon coupling, which entails so-called photon-ALP oscillations as photons propagate through a magnetic field. These oscillations lead to distinctive signatures in the energy spectrum of high-energy photons from astrophysical sources, allowing one to probe the existence of ALPs. In particular, photon-ALP oscillations will induce energy dependent oscillatory features, or "ALP wiggles", in the photon spectra. We propose to use the discrete power spectrum to search for ALP wiggles and present a model-independent statistical test. By using PKS 2155-304 as an example, we show that the method has the potential to significantly improve the experimental sensitivities for ALP wiggles, and that the ALP wiggles may be detected using the Cherenkov Telescope Array (CTA) for optimistic values of the photon-ALP coupling constant and the magnetic field. Moreover, we discuss how these sensitivities depend on the modelling of the magnetic field. We find that the use of realistic magnetic field models, due to their larger cosmic variance, substantially enhances detection prospects compared to the use of simplified models.

   hep-phastro-ph.HEJCAP(2024)·8 citations
10. 10*

    Accommodating the H$(650)$ in the HEFT

    Iñigo Asiáin🇪🇸 · Domènec Espriu🇪🇸 · Federico Mescia🇪🇸

    Loss of unitarity in an effective field theory is often cured by the appearance of dynamical resonances, revealing the presence of new degrees of freedom. These resonances may manifest themselves when suitable unitarization techniques are implemented in the effective theory, which in the scalar-isoscalar channel require making use of the coupled-channel formalism. Conversely, experimental detection of a resonance may provide interesting information on the couplings and constants of the relevant effective theory. By applying the systematical procedure developed in previous works, we will attempt to accommodate a possible scalar resonance with mass around $650$ GeV for which there is preliminary evidence at the LHC in the vector boson fusion channel. The results are interesting: the resonance can be accommodated within the experimentally allowed range of next-to-leading order coefficients in the HEFT but in a rather non-trivial manner. Interestingly, its width and production cross section turn out to agree with the tentative experimental results.

    hep-phPRD(2023)·4 citations
11. 11*

    Present and future constraints on flavor-dependent long-range interactions of high-energy astrophysical neutrinos

    Sanjib Kumar Agarwalla🇮🇳 · Mauricio Bustamante🇩🇰 · Sudipta Das🇮🇳 · Ashish Narang🇮🇳

    The discovery of new, flavor-dependent neutrino interactions would provide compelling evidence of physics beyond the Standard Model. We focus on interactions generated by the anomaly-free, gauged, abelian lepton-number symmetries, specifically $L_e-L_{\mu }$, $L_e-L_{\tau }$, and $L_{\mu }-L_{\tau }$, that introduce a new matter potential sourced by electrons and neutrons, potentially impacting neutrino flavor oscillations. We revisit, revamp, and improve the constraints on these interactions that can be placed via the flavor composition of the diffuse flux of high-energy astrophysical neutrinos, with TeV-PeV energies, i.e., the proportion of ${\nu }_e$, ${\nu }_{\mu }$, and ${\nu }_{\tau }$ in the flux. Because we consider mediators of these new interactions to be ultra-light, lighter than $10^{-10}$ eV, the interaction range is ultra-long, from km to Gpc, allowing vast numbers of electrons and neutrons in celestial bodies and the cosmological matter distribution to contribute to this new potential. We leverage the present-day and future sensitivity of high-energy neutrino telescopes and of oscillation experiments to estimate the constraints that could be placed on the coupling strength of these interactions. We find that, already today, the IceCube neutrino telescope demonstrates potential to constrain flavor-dependent long-range interactions significantly better than existing constraints, motivating further analysis. We also estimate the improvement in the sensitivity due to the next-generation neutrino telescopes such as IceCube-Gen2, Baikal-GVD, KM3NeT, P-ONE, and TAMBO.

    hep-phastro-ph.HEhep-exphysics.ins-detJHEP(2023)·22 citations
12. 12*

    Multi-charmed and singled charmed hadrons from coalescence: yields and ratios in different collision systems at LHC

    Vincenzo Minissale (1 and 2)🇮🇹 · Salvatore Plumari (1 and 2)🇮🇹 · Yifeng Sun (3)🇨🇳 · Vincenzo Greco (1 and 2) ((1) Department of Physics and Astronomy "E.Majorana", University of Catania, Catania, Italy, (2) Laboratori Nazionali del Sud, INFN-LNS, Catania, Italy, (3) School of Physics and Astronomy, Shanghai Key Laboratory for Particle Physics and Cosmology, and Key Laboratory for Particle Astrophysics and Cosmology (MOE), Shanghai Jiao Tong University, Shanghai, China)🇮🇹

    We study the production of charmed and multi-charmed hadrons in ultra-relativistic Heavy Ion Collisions coupling the transport approach for charm dynamics in the medium to an hybrid hadronization model of coalescence plus fragmentation. In this paper, we mainly discuss the particle yields for single charmed and multi-charmed baryons focusing mainly on the production of ${\Xi }_{cc}$ and ${\Omega }_{ccc}$. We provide first predictions for PbPb collision in 0-10% centrality class and then we explore the system size dependence through KrKr, to ArAr and OO collisions, planned within the ALICE3 experiment. In these cases, a monotonic behavior for the yields emerges which can be tested in future experimental data. We found about three order of magnitude increase in the production of ${\Omega }_{ccc}$ in PbPb collisions compared with the yield in small collision systems like OO collisions. Furthermore, we investigate the effects on the ${\Omega }_{ccc}$ particle production and spectra coming from the modification of the charm quark distribution due to the different size of the collision systems comparing also to the case of thermalized charm distributions. These results suggest that observation on the ${\Omega }_{ccc}$ spectra and their evolution across system size can give information about the partial thermalization of the charm quark distribution as well as to its wave function width.

    hep-phnucl-thEPJC(2024)·29 citations
13. 13*

    Hadronic molecules ${\eta }_c{\eta }_c$ and ${\chi }_{c0}{\chi }_{c0}$

    S. S. Agaev🇦🇿 · K. Azizi🇮🇷 · B. Barsbay🇹🇷 · H. Sundu🇹🇷

    The fully charmed hadronic scalar molecules ${\mathcal{M}}_1={\eta }_c{\eta }_c$ and ${\mathcal{M}}_2={\chi }_{c0}{\chi }_{c0}$ are studied in the context of the QCD sum rule method. The masses $m$, $\tilde{m}$ and current couplings $f$, $\tilde{f}$ of these states are calculated using the two-point sum rule approach. The obtained results $m=(6264\pm 50)\mathrm{MeV}$ and $\tilde{m}=(6954\pm 50)\mathrm{MeV}$ are employed to determine their decay channels. It is demonstrated that the processes ${\mathcal{M}}_1\to J/\psi J/\psi$ and ${\mathcal{M}}_1\to {\eta }_c{\eta }_c$ are kinematically allowed decay modes of ${\mathcal{M}}_1$. The molecule ${\mathcal{M}}_2$ decays to $J/\psi J/\psi$, $J/\psi {\psi }^{\prime }$, ${\eta }_c{\eta }_c$, ${\eta }_c{\eta }_c(2S)$, ${\eta }_c{\chi }_{c1}(1P)$, and ${\chi }_{c0}{\chi }_{c0}$ mesons. The partial widths all of these processes are evaluated by means of the three-point sum rule calculations, which are necessary to extract the strong couplings $g_i$ at vertices ${\mathcal{M}}_{1}J/\psi J/\psi$, ${\mathcal{M}}_1{\eta }_c{\eta }_c$, and others. Our estimates for the full widths of the molecules ${\Gamma }_{{\mathcal{M}}_1}=(320\pm 72)\mathrm{MeV}$ and ${\Gamma }_{{\mathcal{M}}_2}=(138\pm 18)\mathrm{MeV}$, as well as their masses are compared with parameters of the $X$ resonances discovered by the LHCb-ATLAS-CMS Collaborations in the di-$J/\psi$ and $J/\psi {\psi }^{\prime }$ invariant mass distributions. We argue that the molecule ${\mathcal{M}}_1$ can be considered as a real candidate to the resonance $X(6200)$. The structure ${\mathcal{M}}_2$ may be interpreted as $X(6900)$ or one of its components in combination with a scalar tetraquark.

    hep-phhep-exhep-latEur.Phys.J.Plus(2023)·37 citations
14. 14*

    IceCube and the origin of ANITA-IV events

    Toni Bertólez-Martínez🇪🇸 · Carlos A. Argüelles🇺🇸 · Ivan Esteban🇺🇸 · Jacobo Lopez-Pavon🇪🇸 · Ivan Martinez-Soler🇺🇸 · Jordi Salvado🇪🇸

    Recently, the ANITA collaboration announced the detection of new, unsettling upgoing Ultra-High-Energy (UHE) events. Understanding their origin is pressing to ensure success of the incoming UHE neutrino program. In this work, we study their internal consistency and the implications of the lack of similar events in IceCube. We introduce a generic, simple parametrization to study the compatibility between these two observatories in Standard Model-like and Beyond Standard Model scenarios: an incoming flux of particles that interact with Earth nucleons with cross section $\sigma$, producing particle showers along with long-lived particles that decay with lifetime $\tau$ and generate a shower that explains ANITA observations. We find that the ANITA angular distribution imposes significant constraints, and when including null observations from IceCube only $\tau \sim 10^{-3}$ - $10^{-2}\mathrm{s}$ and $\sigma \sim 10^{-33}$ - $10^{-32}\mathrm{c}{\mathrm{m}}^2$ can explain the data. This hypothesis is testable with future IceCube data. Finally, we discuss a specific model that can realize this scenario. Our analysis highlights the importance of simultaneous observations by high-energy optical neutrino telescopes and new UHE radio detectors to uncover cosmogenic neutrinos or discover new physics.

    hep-phastro-ph.HEhep-exJHEP(2023)·9 citations
15. 15*

    Spectral distortions of astrophysical blackbodies as axion probes

    Jae Hyeok Chang🇺🇸 · Reza Ebadi🇺🇸 · Xuheng Luo🇺🇸 · Erwin H. Tanin🇺🇸

    Recent studies reveal that more than a dozen of white dwarfs displaying near-perfect blackbody spectra in the optical range have been lurking in the Sloan Digital Sky Survey catalog. We point out that, in a way analogous to the Cosmic Microwave Background, these stars serve as excellent testbeds for new physics. Specifically, we show how their observed lack of spectral distortions translates into limits on the parameter space of axions with electromagnetic coupling. The prospects for future improvements are also discussed.

    hep-phastro-ph.COastro-ph.HEastro-ph.SRPRD(2023)·7 citations
16. 16*

    A Spectral Metric for Collider Geometry

    Andrew J. Larkoski🇺🇸 · Jesse Thaler🇺🇸

    By quantifying the distance between two collider events, one can triangulate a metric space and reframe collider data analysis as computational geometry. One popular geometric approach is to first represent events as an energy flow on an idealized celestial sphere and then define the metric in terms of optimal transport in two dimensions. In this paper, we advocate for representing events in terms of a spectral function that encodes pairwise particle angles and products of particle energies, which enables a metric distance defined in terms of one-dimensional optimal transport. This approach has the advantage of automatically incorporating obvious isometries of the data, like rotations about the colliding beam axis. It also facilitates first-principles calculations, since there are simple closed-form expressions for optimal transport in one dimension. Up to isometries and event sets of measure zero, the spectral representation is unique, so the metric on the space of spectral functions is a metric on the space of events. At lowest order in perturbation theory in electron-positron collisions, our metric is simply the summed squared invariant masses of the two event hemispheres. Going to higher orders, we present predictions for the distribution of metric distances between jets in fixed-order and resummed perturbation theory as well as in parton-shower generators. Finally, we speculate on whether the spectral approach could furnish a useful metric on the space of quantum field theories.

    hep-phhep-exhep-thJHEP(2023)·18 citations
17. 17*

    ALP dark matter with non-periodic potentials: parametric resonance, halo formation and gravitational signatures

    Aleksandr Chatrchyan🇩🇪 · Cem Eröncel🇩🇪 · Matthias Koschnitzke🇩🇪 · Géraldine Servant🇩🇪

    Axion-like particles (ALPs) are leading candidates to explain the dark matter in the universe. Their production via the misalignment mechanism has been extensively studied for cosine potentials characteristic of pseudo-Nambu-Goldstone bosons. In this work we investigate ALPs with non-periodic potentials, which allow for large misalignment of the field from the minimum. As a result, the ALP can match the relic density of dark matter in a large part of the parameter space. Such potentials give rise to self-interactions which can trigger an exponential growth of fluctuations in the ALP field via parametric resonance, leading to the fragmentation of the field. We study these effects with both Floquet analysis and lattice simulations. Using the Press-Schechter formalism, we predict the halo mass function and halo spectrum arising from ALP dark matter. These halos can be dense enough to produce observable gravitational effects such as astrometric lensing, diffraction of gravitational wave signals from black hole mergers, photometric microlensing of highly magnified stars, perturbations of stars in the galactic disk or stellar streams. These effects would provide a probe of dark matter even if it does not couple to the Standard Model. They would not be observable for halos predicted for standard cold dark matter and for ALP dark matter in the standard misalignment mechanism. We determine the relevant regions of parameter space in the (ALP mass, decay constant)-plane and compare predictions in different axion fragmentation models.

    hep-phastro-ph.COJCAP(2023)·27 citations
18. 18*

    Electroweak input schemes and universal corrections in SMEFT

    Anke Biekötter🇩🇪 · Benjamin D. Pecjak🇬🇧 · Darren J. Scott🇩🇪 · Tommy Smith🇬🇧

    The choice of an electroweak (EW) input scheme is an important component of perturbative calculations in Standard Model Effective Field Theory (SMEFT). In this paper we perform a systematic study of three different EW input schemes in SMEFT, in particular those using the parameter sets $\{M_W,M_Z,G_F\}$, $\{M_W,M_Z,\alpha \}$, or $\{\alpha ,M_Z,G_F\}$. We discuss general features and calculate decay rates of $Z$ and $W$ bosons to leptons and Higgs decays to bottom quarks in these three schemes up to next-to-leading order (NLO) in dimension-six SMEFT. We explore the sensitivity to Wilson coefficients and perturbative convergence in the different schemes, and show that while the latter point is more involved than in the Standard Model, the dominant scheme-dependent NLO corrections are universal and can be taken into account by a simple set of substitutions on the leading-order results. Residual NLO corrections are then of similar size between the different input schemes, and performing calculations in multiple schemes can give a useful handle on theory uncertainties in SMEFT predictions and fits to data.

    hep-phJHEP(2023)·35 citations
19. 19*

    Gravity of gluonic fluctuations and the value of the cosmological constant

    Kris Mackewicz🇺🇸 · Craig Hogan🇺🇸

    We analyze the classical linear gravitational effect of idealized pion-like dynamical systems, consisting of light quarks connected by attractive gluonic material with a stress-energy $p=-\rho c^2$ in one or more dimensions. In one orbit of a system of total mass $M$, quarks of mass $m<<M$ expand apart initially with $v/c\sim 1$, slow due to the gluonic attraction, reach a maximum size $R_0\sim \hslash /Mc$, then recollapse. We solve the linearized Einstein equations and derive the effect on freely falling bodies for two systems: a gluonic bubble model where uniform gluonic stress-energy fills a spherical volume bounded by a 2D surface comprising the quarks' rest mass, and a gluonic string model where a thin string connects two pointlike quarks. The bubble model is shown to produce a secular mean outward residual velocity of test particles that lie within its orbit. It is shown that the mean gravitational repulsion of bubble-like virtual-pion vacuum fluctuations agrees with the measured value of the cosmological constant, for a bubble with a radius equal to about twice the pion de Broglie length. These results support the view that the gravity of standard QCD vacuum fluctuations is the main source of cosmic acceleration.

    hep-phastro-ph.COgr-qcClass.Quant.Grav.(2024)·2 citations
20. 20*

    New constraints on PDFs with CMS data

    Luis F. Alcerro (On behalf of the CMS Collaboration)🇺🇸

    Recent results on inclusive jet production and production of a W boson in association with a charm quark by the CMS Collaboration are presented in this proceeding. The impact of these measurements on proton PDFs are also discussed.

    ↳ hep-exhep-phActa Phys.Polon.Supp.(2023)·0 citations
21. 21*

    Black holes as the source of dark energy: a stringent test with high-redshift JWST AGNs

    Lei Lei🇨🇳 · Lei Zu🇨🇳 · Guan-Wen Yuan🇨🇳 · Zhao-Qiang Shen🇨🇳 · Yi-Ying Wang🇨🇳 · Yuan-Zhu Wang🇨🇳 · Zhen-Bo Su🇨🇳 · Wen-ke Ren🇨🇳 · Shao-Peng Tang🇨🇳 · Hao Zhou🇨🇳 · Chi Zhang🇨🇳 · Zhi-Ping Jin🇨🇳 and 3 other authors

    Studies have proposed that there is evidence for cosmological coupling of black holes (BHs) with an index of $k\approx 3$; hence, BHs serve as the astrophysical source of dark energy. However, the data sample is limited for the redshifts of $\le 2.5$. In recent years, the James Webb Space Telescope (JWST) has detected many high-redshift active galactic nuclei (AGNs) and quasars. Among the JWST NIRSpec-/NIRCam-resolved AGNs, three are determined to be in early-type host galaxies with a redshift of $z\sim 4.5--7$. However, their $M_{\star }$ and $M_{\mathrm{BH}}$ are in tension with the predicted cosmological coupling of black holes with $k=3$ at a confidence level of $\sim 2\sigma$, which challenges the hypothesis that BHs serve as the origin of dark energy. Future work on high-redshift AGNs using the JWST will further assess such a hypothesis by identifying more early-type host galaxies in the higher mass range.

    ↳ astro-ph.COgr-qchep-phphysics.pop-phSCPMA(2024)·32 citations
22. 22*

    One loop to rule them all: Perturbativity in the presence of ultra slow-roll dynamics

    Gabriele Franciolini🇮🇹 · Antonio Junior Iovino🇮🇹 · Marco Taoso🇮🇹 · Alfredo Urbano🇮🇹

    We discuss the issue of perturbativity in single-field inflationary models with a phase of ultra slow-roll (USR) tailor suited to generate an order-one abundance of primordial black holes (PBHs). More in detail, we impose the condition that loop corrections made up of short-wavelength modes enhanced by the USR dynamics do not alter the tree-level power spectrum of curvature perturbations. In our analysis, the USR phase is preceded and followed by two stages of ordinary slow-roll (SR), and we model the resulting SR/USR/SR dynamics using both instantaneous and smooth transitions. Focusing on scales relevant for CMB observations, we find that it is not possible, with these arguments, to rule out the scenario of PBH formation via USR, not even in the limit of instantaneous transition. However, we also find that loop corrections of short modes on the power spectrum of long modes, even though not large enough to violate perturbativity requirements, remain appreciable and, most importantly, are not tamed in realistic realisations of smooth SR/USR/SR transitions. This makes perturbativity a powerful theoretical tool to constrain USR dynamics. We extend the analysis at any scale beyond those relevant for CMB observations. We find that loop corrections of short modes remain within the few percent if compared to the tree-level power spectrum. However, we also find one notable exception of phenomenological relevance: we show that the so-called dip in the power spectrum of curvature perturbation is an artifact of the tree-level computation.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2024)·124 citations
23. 23*

    Hidden Conformal Symmetry from the Lattice

    LSD Collaboration: T. Appelquist🇺🇸 · R. C. Brower🇺🇸 · K. K. Cushman🇺🇸 · G. T. Fleming🇺🇸 · A. Gasbarro🇨🇭 · A. Hasenfratz🇺🇸 · J. Ingoldby🇮🇹 · X. Y. Jin🇺🇸 · E. T. Neil🇺🇸 · J. C. Osborn🇺🇸 · C. Rebbi🇺🇸 · E. Rinaldi🇯🇵 and 4 other authors

    We analyze newly expanded and refined data from lattice studies of an SU(3) gauge theory with eight Dirac fermions in the fundamental representation. We focus on the light composite states emerging from these studies, consisting of a set of pseudoscalars and a single light scalar. We first consider the view that this theory is just outside the conformal window. In this case, the pseudoscalars arise from spontaneous breaking of chiral symmetry. Identifying the scalar in this case as an approximate dilaton, we fit the lattice data to a dilaton effective field theory, finding that it yields a good fit even at lowest order. For comparison, we then consider the possibility that the theory is inside the conformal window. The fermion mass provides a deformation, triggering confinement. We employ simple scaling laws to fit the lattice data, and find that it is of lesser quality.

    ↳ hep-lathep-phPRD(2023)·27 citations
24. 24*

    An Introduction to Noncommutative Physics

    Shi-Dong Liang🇨🇳 · Matthew J. Lake🇹🇭

    In recent years, many new developments in theoretical physics, and in practical applications rely on different techniques of noncommutative algebras. In this review, we introduce the basic concepts and techniques of noncommutative physics in a range of areas, including classical physics, condensed matter systems, statistical mechanics, and quantum mechanics, and we present some important examples of noncommutative algebras, including the classical Poisson brackets, the Heisenberg algebra, Lie and Clifford algebras, the Dirac algebra, and the Snyder and Nambu algebras. Potential applications of noncommutative structures in high-energy physics and gravitational theory are also discussed. In particular, we review the formalism of noncommutative quantum mechanics based on the Seiberg--Witten map and propose a parameterization scheme to associate the noncommutative parameters with the Planck length and the cosmological constant. We show that noncommutativity gives rise to an effective gauge field, in the Schrödinger and Pauli equations. This term breaks translation and rotational symmetries in the noncommutative phase space, generating intrinsic quantum fluctuations of the velocity and acceleration, even for free particles. This review is intended as an introduction to noncommutative phenomenology for physicists, as well as a basic introduction to the mathematical formalisms underlying these effects.

    ↳ hep-thgr-qchep-phPhysics(2023)·13 citations
25. 25*

    Impact of the pre-equilibrium phase for the determination of nuclear geometry in high-energy isobar collisions

    Fernando G. Gardim🇧🇷 · André V. Giannini🇧🇷 · Frédérique Grassi🇧🇷 · Kevin P. Pala🇧🇷 · Willian M. Serenone🇧🇷

    Ultrarelativistic isobar collisions have been proposed as a useful tool to investigate nuclear structure. These systems are not created in equilibrium, rather undergo a pre-thermalization stage. In this stage, some of the initial structure information may be lost and additional effects introduced. The objective of this paper is to study this possibility in the extreme case of a "free-streaming" pre-equilibrium stage. We do this by computing estimators for ratios of various measured (or measurable) quantities (elliptic and triangular flows, mean transverse momentum and associated cumulants, correlators between elliptic or triangular flows and mean transverse momentum, symmetric cumulant and two-plane correlator) and study their sensitivity to the duration of the free-streaming stage. We find that the correlators between elliptic or triangular flows and mean transverse momentum, the so-called ${\rho }_2$ and ${\rho }_3$, are indeed sensitive to the duration of the free-streaming stage and that the normalized symmetric cumulant, $\epsilon NSC(2,3)$ might also depend on this duration.

    ↳ nucl-thhep-phPRC(2024)·3 citations
26. 26*

    Edge-Induced Excitations in Bi${}_2$Te${}_3$ from Spatially-Resolved Electron Energy-Gain Spectroscopy

    Helena La · Abel Brokkelkamp · Stijn van der Lippe · Jaco ter Hoeve🇳🇱 · Juan Rojo🇳🇱 · Sonia Conesa-Boj🇳🇱

    Among the many potential applications of topological insulator materials, their broad potential for the development of novel tunable plasmonics at THz and mid-infrared frequencies for quantum computing, terahertz detectors, and spintronic devices is particularly attractive. The required understanding of the intricate relationship between nanoscale crystal structure and the properties of the resulting plasmonic resonances remains, however, elusive for these materials. Specifically, edge- and surface-induced plasmonic resonances, and other collective excitations, are often buried beneath the continuum of electronic transitions, making it difficult to isolate and interpret these signals using techniques such as electron energy-loss spectroscopy (EELS). Here we focus on the experimentally clean energy-gain EELS region to characterise collective excitations in the topologically insulating material Bi${}_2$Te${}_3$ and correlate them with the underlying crystalline structure with nanoscale resolution. We identify with high significance the presence of a distinct energy-gain peak around -0.8 eV, with spatially-resolved maps revealing that its intensity is markedly enhanced at the edge regions of the specimen. Our findings illustrate the reach of energy-gain EELS analyses to accurately map collective excitations in quantum materials, a key asset in the quest towards new tunable plasmonic devices.

    ↳ cond-mat.mes-hallcond-mat.mtrl-scihep-phUltramicroscopy(2023)·1 citation
27. 27*

    Weakly-Supervised Anomaly Detection in the Milky Way

    Mariel Pettee🇺🇸 · Sowmya Thanvantri🇺🇸 · Benjamin Nachman🇺🇸 · David Shih🇺🇸 · Matthew R. Buckley🇺🇸 · Jack H. Collins🇺🇸

    Large-scale astrophysics datasets present an opportunity for new machine learning techniques to identify regions of interest that might otherwise be overlooked by traditional searches. To this end, we use Classification Without Labels (CWoLa), a weakly-supervised anomaly detection method, to identify cold stellar streams within the more than one billion Milky Way stars observed by the Gaia satellite. CWoLa operates without the use of labeled streams or knowledge of astrophysical principles. Instead, we train a classifier to distinguish between mixed samples for which the proportions of signal and background samples are unknown. This computationally lightweight strategy is able to detect both simulated streams and the known stream GD-1 in data. Originally designed for high-energy collider physics, this technique may have broad applicability within astrophysics as well as other domains interested in identifying localized anomalies.

    ↳ astro-ph.GAcs.LGhep-phphysics.data-anMNRAS(2023)·14 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.