Fri·Jul 28, 2023Friday·July 28, 2023

1. 01*

   Dark matter in compact stars

   Joseph Bramante🇨🇦 · Nirmal Raj🇮🇳

   White dwarfs and neutron stars are far-reaching and multi-faceted laboratories in the hunt for dark matter. We review detection prospects of wave-like, particulate, macroscopic and black hole dark matter that make use of several exceptional properties of compact stars, such as ultra-high densities, deep fermion degeneracies, low temperatures, nucleon superfluidity, strong magnetic fields, high rotational regularity, and significant gravitational wave emissivity. Foundational topics first made explicit in this document include the effect of the ``propellor phase" on neutron star baryonic accretion, and the contribution of Auger and Cooper pair breaking effects to neutron star heating by dark matter capture.

   hep-phastro-ph.HEastro-ph.SRhep-exPhys.Rept.(2024)·130 citations
2. 02*

   Fluid dynamics of charm quarks in the quark--gluon plasma

   Federica Capellino🇩🇪 · Andrea Dubla🇩🇪 · Stefan Floerchinger🇺🇸 · Eduardo Grossi🇮🇹 · Andreas Kirchner🇩🇪 · Silvia Masciocchi🇩🇪

   A fluid-dynamic approach to charm-quark diffusion in the quark-gluon plasma (QGP) is developed for the first time. Results for integrated yields and momentum distributions of charmed hadrons obtained with a fluid-dynamic description for the dynamics of the QGP coupled to an additional heavy-quark-antiquark current are shown. In addition to the thermodynamic Equation of State (EoS), this description uses a heavy-quark diffusion constant which we take from Lattice QCD calculations. The results describe quantitatively experimental data measured at the LHC at the center-of-mass energy of $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV up to $p_{\mathrm{T}}\sim$ 4-5 GeV/$c$, showing that charm quarks undergo a very fast hydrodynamization in the medium created by ultrarelativistic heavy-ion collisions.

   hep-phnucl-thPRD(2023)·27 citations
3. 03*

   T-Model Higgs Inflation in Supergravity

   C. Pallis🇬🇷

   We focus on a simple, natural and predictive T model of inflation in Supergravity employing as inflaton the Higgs field which leads to the spontaneous breaking of a U(1)_(B-L) symmetry at the SUSY GUT scale. We use a renormalizable superpotential, fixed by a U(1) R symmetry, and a Kahler potential which parameterizes the Kahler manifold SU(2,1)/(SU(2)xU(1))x(SU(2)/U(1)) with scalar curvature R_K=-6/N+2/N_0 where 0<N_0<6. The spectral index ns turns out to be close to its present central observational value and the tensor-to-scalar ratio r increases with N<36. The model can be nicely linked to MSSM offering an explanation of the magnitude of the mu parameter consistently with phenomenological data. It also allows for baryogenesis via non-thermal leptogenesis with gravitino as light as 1 TeV.

   hep-phastro-ph.COhep-th6 citations
4. 04*

   Possible formation of Quark-Gluon Plasma in small collision systems at the Large Hadron Collider: Observations and Challenges

   Raghunath Sahoo🇮🇳

   With the advent of unprecedented collision energy at the Large Hadron Collider, CERN, Geneva, a new domain of particle production and possible formation of Quark-Gluon Plasma (QGP) in high-multiplicity proton-proton collisions and the collisions of light nuclei has been a much-discussed topic recently. In this review, I discuss some of the recent observations leading to such a possibility, associated challenges, and some predictions for the upcoming light-nuclei collisions at the LHC.

   hep-phhep-exnucl-exnucl-thSpringer Proc.Phys.(2024)·2 citations
5. 05*

   Two-particle angular correlations in the search for new physics at future $e^{+}{e}^{-}$ colliders

   E. Musumeci (1)🇪🇸 · R. Perez-Ramos (2 and 3)🇫🇷 · A. Irles (1)🇪🇸 · I. Corredoira (4)🇪🇸 · V. A. Mitsou (1)🇪🇸 · E. Sarkisyan-Grinbaum (5 and 6)🇨🇭 · M. A. Sanchis-Lozano (1) ((1) IFIC, Universitat de València and CSIC, Paterna (Valencia), Spain, (2) DRII-IPSA, Ivry-sur-Seine, France, (3) Laboratoire de Physique Théorique et Hautes Energies (LPTHE), Sorbonne Université et CNRS, Paris Cedex, France, (4) Instituto Galego de Física de Altas Enerxìas (IGFAE, USC), Spain, (5) Experimental Physics Department, CERN, Geneva, Switzerland, (6) Department of Physics, The University of Texas at Arlington, Arlington, TX USA)🇪🇸

   The analysis of angular particle correlations can yield valuable insights into the initial state of matter in high-energy collisions, thereby potentially revealing the existence of Beyond the Standard Model scenarios such as Hidden Valley (HV). In this study, we focus on a QCD-like hidden sector with relatively massive HV quarks ($\lesssim 100$~GeV) which might enlarge and strengthen azimuthal correlations of final-state SM hadrons. In particular, we study the formation and possible observation of \textit{ridge-like} structures in the angular two-particle correlation function at future $e^{+}{e}^{-}$ colliders, with a much cleaner environment than in hadron colliders, such as the LHC.

   hep-phhep-ex6 citations
6. 06*

   Cosmic Birefringence by Dark Photon

   Sung Mook Lee🇰🇷 · Dong Woo Kang🇰🇷 · Jinn-Ouk Gong🇰🇷 · Donghui Jeong🇺🇸 · Dong-Won Jung🇰🇷 · Seong Chan Park🇰🇷

   We study the kinetic mixing between the cosmic microwave background (CMB) photon and the birefringent dark photon. These birefringent dark photon may exist in parity-violating dark sector, for example, through the coupling to axion field. We show that the birefringence of the dark photon propagates to the CMB photon, but the resulting birefringence may not be isotropic over the sky, but will be anisotropic in general. Moreover, our investigation sheds light on the essential role played by kinetic mixing in the generation of two fundamental characteristics of the CMB: circular polarization and spectral distortion.

   hep-phastro-ph.COgr-qchep-thJCAP(2024)·5 citations
7. 07*

   BSM patterns in scalar-sector coupling modifiers

   Christoph Englert🇬🇧 · Wrishik Naskar🇬🇧 · Dave Sutherland🇬🇧

   We consider what multiple Higgs interactions may yet reveal about the scalar sector. We estimate the sensitivity of a Feynman topology-templated analysis of weak boson Higgs pair production at present and future colliders - where the signal is a function of the Higgs coupling modifiers ${\kappa }_V$, ${\kappa }_{2V}$, and ${\kappa }_{\lambda }$. While measurements are statistically limited at the LHC, they are under general perturbative control at present and future colliders, departures from the SM expectation give rise to a significant future potential for BSM discrimination in ${\kappa }_{2V}$. We explore the landscape of BSM models in the space of deviations in ${\kappa }_V$, ${\kappa }_{2V}$, and ${\kappa }_{\lambda }$, highlighting models that have measurable order-of-magnitude enhancements in either ${\kappa }_{2V}$ or ${\kappa }_{\lambda }$, relative to their deviation in the single Higgs coupling ${\kappa }_V$.

   hep-phhep-exJHEP(2023)·15 citations
8. 08*

   Fate of homogeneous ${\mathbb{Z}}_2$-symmetric scalar condensates

   Wen-Yuan Ai🇬🇧 · Zi-Liang Wang🇨🇳

   Dark matter, if represented by a ${\mathbb{Z}}_2$-symmetric scalar field, can manifest as both particles and condensates. In this paper, we study the evolution of an oscillating homogeneous condensate of a ${\mathbb{Z}}_2$-symmetric scalar field in a thermal plasma in an FLRW universe. We focus on the perturbative regime where the oscillation amplitude is sufficiently small so that parametric resonance is inefficient. This perturbative regime necessarily comprises the late stage of the condensate decay and determines its fate. The coupled coarse-grained equations of motion for the condensate, radiation, and spacetime are derived from first principles using nonequilibrium quantum field theory. We obtain analytical expressions for the relevant microscopic quantities that enter the equations of motion and solve the latter numerically. We find that there is always a nonvanishing relic abundance for a condensate with a ${\mathbb{Z}}_2$ symmetry that is not spontaneously broken. This is because its decay rate decreases faster than the Hubble parameter at late times due to either the amplitude dependence or the temperature dependence in the condensate decay rate. Consequently, accounting for the condensate contribution to the overall dark matter relic density is essential for ${\mathbb{Z}}_2$ scalar singlet dark matter.

   hep-phastro-ph.COhep-thJCAP(2024)·11 citations
9. 09*

   Study of the nonleptonic decay ${\Xi }_c^0\to {\Lambda }_c^{+}{\pi }^{-}$ in the covariant confined quark model

   Mikhail A. Ivanov🇷🇺 · Valery E. Lyubovitskij🇩🇪 · Zhomart Tyulemissov🇷🇺

   The nonleptonic decay ${\Xi }_c^0\to {\Lambda }_c^{+}{\pi }^{-}$ with $\Delta C=0$ is systematically studied in the framework of the covariant confined quark model with accounting for both short and long distance effects. The short distance effects are induced by four topologies of external and internal weak $W^{\pm }$ exchange, while long distance effects are saturated by an inclusion of the so-called pole diagrams with an intermediate ${\frac{1}{2}}^{+}$ and ${\frac{1}{2}}^{-}$ baryon resonances. The contributions from ${\frac{1}{2}}^{+}$~resonances are calculated straightforwardly by accounting for single charmed ${\Sigma }_c^0$ and ${\Xi }_c^{{}^{\prime }+}$~baryons whereas the contributions from ${\frac{1}{2}}^{-}$~resonances are calculated by using the well-known soft-pion theorem in the current-algebra approach. It allows to express the parity-violating S-wave amplitude in terms of parity-conserving matrix elements. It is found that the contribution of external and internal $W$-exchange diagrams is significantly suppressed by more than one order of magnitude in comparison with data. The pole diagrams play the major role to get consistency with experiment.

   hep-phhep-exPRD(2023)·7 citations
10. 10*

    Search for Light Dark Matter with accelerator and direct detection experiments: comparison and complementarity of recent results

    S. N. Gninenko🇷🇺 · D. V. Kirpichnikov🇷🇺 · N. V. Krasnikov🇷🇺

    We discuss the most sensitive constraints on Light Dark Matter (LDM) from accelerator experiments NA64 and BaBar and compare it with recent results from direct searches at XENON1T, DAMIC-M, SuperCDMS, and DarkSide-50. We show that for the dark photon ($A^{\prime }$) model with scalar LDM, NA64 gives more stringent bounds for $A^{\prime }$ masses $m_{A^{\prime }}\le 0.15GeV$ than direct searches. Moreover, for the case of Majorana LDM the damping DM velocity $v$ factor, $v^2\sim O(10^{-6})$, for the elastic LDM electron(nucleon) cross section makes direct observation of Majorana LDM extremely challenging, while the absence of this suppression in the NA64 case gives an advantage to the experiment. The similar situation takes place for pseudo-Dirac LDM. The BaBar provides the most stringent bounds for $A^{\prime }$ masses $m_{A^{\prime }}\ge 0.35GeV$. For scalar LDM the direct detection experiments give more stringent bounds at $m_{A^{\prime }}\ge 0.35GeV$ while for Majorana and pseudo-Dirac LDM case, the BaBar bounds are more stringent. The complementarity of the two approaches in searching for LDM is underlined.

    hep-ph6 citations
11. 11*

    Parity Solution to the Strong CP Problem and a Unified Framework for Inflation, Baryogenesis, and Dark Matter

    K. S. Babu🇺🇸 · Rabindra N. Mohapatra🇺🇸 · Nobuchika Okada🇺🇸

    It has been known for some time that asymptotic parity invariance of weak interactions can provide a solution to the strong CP problem without the need for the axion. Left-right symmetric theories which employ a minimal Higgs sector consisting of a left-handed and a right-handed doublet is an example of such a theory wherein all fermion masses arise through a generalized seesaw mechanism. In this paper we present a way to understand the origin of matter-antimatter asymmetry as well as the dark matter content of the universe in these theories using the Affleck-Dine (AD) leptogenesis mechanism and inflaton decay, respectively. Three gauge singlet fermions are needed for this purpose, two of which help to implement the Dirac seesaw for neutrino masses while the third one becomes the non-thermal warm dark matter candidate. A soft lepton number breaking term involving the AD scalar field is used to generate lepton asymmetry which suffers no wash-out effects and maintains the Dirac nature of neutrinos. This framework thus provides a unified description of many of the unresolved puzzles of the standard model that require new physics.

    hep-phJHEP(2024)·7 citations
12. 12*

    Multicomponent Scalar Dark Matter with an Extended Gauge Sector

    Baradhwaj Coleppa🇮🇳 · Kousik Loho🇮🇳 · Agnivo Sarkar🇮🇳

    We consider an extension of the Standard Model of particle physics with an additional $SU(2)$ gauge sector along with an additional scalar bidoublet and a non-linear sigma field. The neutral components of the bidoublet serve as dark matter candidates by virtue of the bidoublet being odd under a $Z_2$ symmetry. Generic beyond Standard Model constraints like vacuum stability, invisible decay of higgs, Higgs alignment limit and collider constraints on heavy gauge bosons restrict the parameter space of this model. In this multicomponent dark matter scenario, we investigate the interplay between the annihilation and co-annihilation channels originating from the new gauge sector as those contribute to the relic abundance. We also inspect the direct detection constraints on scattering cross-sections of the dark matter particles with the detector nucleons and present our observations.

    hep-phEPJC(2024)·6 citations
13. 13*

    Gravitational form factors of $\Delta$ baryon via QCD sum rules

    Z. Dehghan🇮🇷 · K. Azizi🇮🇷 · U. Özdem🇹🇷

    The gravitational form factors of a hadron are defined through the matrix elements of the energy-momentum tensor current, which can be decomposed into the quark and gluonic parts, between the hadronic states. These form factors provide important information for answering fundamental questions about the distribution of the energy, the spin, the pressure and the shear forces inside the hadrons. Theoretical and experimental studies of these form factors provide exciting insights on the inner structure and geometric shapes of hadrons. Inspired by this, the gravitational form factors of $\Delta$ resonance are calculated by employing the QCD sum rule approach. The acquired gravitational form factors are used to calculate the composite gravitational form factors like the energy and angular momentum multipole form factors, D-terms related to the mechanical properties like the internal pressure and shear forces as well as the mass radius of the system. The predictions are compared with the existing results in the literature.

    hep-phhep-exhep-latPRD(2023)·17 citations
14. 14*

    New observables for testing Bell inequalities in $W$ boson pair production

    Qi Bi🇨🇳 · Qing-Hong Cao🇨🇳 · Kun Cheng🇨🇳 · Hao Zhang🇨🇳

    We show that testing Bell inequalities in $W^{\pm }$ pair systems by measuring their angular correlation suffers from the ambiguity in kinetical reconstruction of the di-lepton decay mode. We further propose a new set of Bell observables based on the measurement of the linear polarization of the $W$ bosons, providing a realistic observable to test Bell inequalities in $W^{\pm }$ pair systems for the first time.

    hep-phhep-exquant-phPRD(2024)·53 citations
15. 15*

    New developments on the WHIZARD event generator

    Jürgen Reuter🇩🇪 · Pia Bredt🇩🇪 · Wolfgang Kilian🇩🇪 · Maximilian Löschner🇩🇪 · Krzysztof Mękała🇩🇪 · Thorsten Ohl🇩🇪 · Tobias Striegl🇩🇪 · Aleksander Filip Żarnecki🇵🇱

    We give a status report on new developments in the WHIZARD event generator, including NLO electroweak automation for $e^{+}{e}^{-}$ colliders, loop-induced processes, POWHEG matching, new features in the UFO interface and the current development for matching between exclusive photon radiation and fixed-order LO/NLO electroweak (EW) corrections. We report on several bug fixes relevant for certain aspects of the ILC250 Monte Carlo (MC) mass production, especially on the normalization of matching EPA samples with full-matrix element samples. Finally, we mention some ongoing work on efficiency improvements regarding parallelization of matrix elements and phase space sampling, as well as plans to revive the top threshold simulation.

    hep-phhep-ex5 citations
16. 16*

    Contribution of hadronic light-by-light scattering to the hyperfine structure of muonium

    V. I. Korobov (BLTP JINR)🇷🇺 · A. V. Eskin (Samara University)🇷🇺 · A. P. Martynenko (Samara University)🇷🇺 · F. A. Martynenko (Samara University)🇷🇺

    The contribution of hadronic scattering of light-by-light to the hyperfine structure of muonium is calculated using experimental data on the transition form factors of two photons into a hadron. The amplitudes of interaction between a muon and an electron with horizontal and vertical exchange are constructed. The contributions due to the exchange of pseudoscalar, axial vector, scalar and tensor mesons are taken into account.

    hep-phphysics.atom-phPRD(2023)·2 citations
17. 17*

    Single inclusive particle production at next-to-leading order in proton-nucleus collisions at forward rapidities: hybrid approach meets TMD factorization

    Tolga Altinoluk🇵🇱 · Néstor Armesto🇪🇸 · Alexander Kovner🇺🇸 · Michael Lublinsky🇮🇱

    We revisit the calculation of the cross section for forward inclusive single hadron production in $pA$ collisions within the hybrid approach. We show that the proper framework to perform this calculation beyond leading order is not the collinear factorization, as has been assumed so far, but the TMD factorized framework. Within the TMD factorized approach we show that all the large transverse logarithms appearing in the fixed order calculation, are resummed into the evolution of the TMD PDFs and TMD FFs with factorization scale. The resulting expressions, when written in terms of TMDs evolved to the appropriate, physically well understood factorization scale, contain no additional large logarithms. The absence of any large logarithms in the resummed result should ensure positivity of the cross section and eradicate the persistent problem that have plagued the previous attempts at calculating this observable in the hybrid approach.

    hep-phnucl-thPRD(2023)·15 citations
18. 18*

    Modular binary octahedral symmetry for flavor structure of Standard Model

    Gui-Jun Ding🇨🇳 · Xiang-Gan Liu🇺🇸 · Jun-Nan Lu🇨🇳 · Ming-Hua Weng🇨🇳

    We have investigated the modular binary octahedral group $2O$ as a flavor symmetry to explain the structure of Standard Model. The vector-valued modular forms in all irreducible representations of this group are constructed. We have classified all possible fermion masses models based on the modular binary octahedral group $2O$. A comprehensive numerical analysis is performed, and we present some benchmark quark/lepton masses models in well agreement with the experimental data. Notably we find a minimal modular invariant model for leptons and quarks, which is able to explain simultaneously the masses and mixing parameters of both quarks and leptons in terms of 14 real free parameters including the modulus $\tau$. The fermion mass hierarchies around the vicinity of the modular fixed points are explored.

    hep-phhep-thJHEP(2023)·23 citations
19. 19*

    Probing an ultralight QCD axion with electromagnetic quadratic interaction

    Hyungjin Kim🇩🇪 · Alessandro Lenoci🇩🇪 · Gilad Perez🇮🇱 · Wolfram Ratzinger🇮🇱

    The axion-gluon coupling is the defining feature of the QCD axion. This feature induces additional and qualitatively different interactions of the axion with standard model particles -- quadratic couplings. Previously, hadronic quadratic couplings have been studied and experimental implications have been explored especially in the context of atomic spectroscopy and interferometry. We investigate additional quadratic couplings to the electromagnetic field and electron mass. These electromagnetic quadratic couplings are generated at the loop level from threshold corrections and are expected to be present in the absence of fine-tuning. While they are generally loop-suppressed compared to the hadronic ones, they open up new ways to search for the QCD axion, for instance via optical atomic clocks. Moreover, due to the velocity spread of the dark matter field, the quadratic nature of the coupling leads to low-frequency fluctuations in any detector setup. These distinctive low-frequency fluctuations offer a way to search for heavier axions. We provide an analytic expression for the power spectral density of this low-frequency background and briefly discuss experimental strategies for a low-frequency background search.

    hep-phPRD(2024)·48 citations
20. 20*

    Exploring Freeze-out and Freeze-in Dark Matter via Effective Froggatt-Nielsen Theory

    Rusa Mandal🇮🇳 · Tom Tong🇩🇪

    Motivated by the dynamical reasons for the hierarchical structure of the Yukawa sector of the Standard Model (SM), we consider an extension of the SM with a complex scalar field, known as `flavon', based on the Froggatt-Nielsen mechanism. In an effective theory approach, the SM fermion masses and mixing patterns are generated in orders of the parameter related to the vacuum expectation value of the flavon field and the cut-off of the effective theory. By introducing right-handed neutrinos, we study the viability of the lightest right-handed neutrino as a dark matter candidate, where the same flavon field acts as a mediator between the dark and the SM sectors. We find that dark matter genesis is achieved both through freeze-out and freeze-in mechanisms encompassing the $\mathcal{O}(\text{GeV})$ -- $\mathcal{O}(\text{TeV})$ mass range of the mediator and the dark matter particle. In addition to tree-level spin-dependent cross section, the model gives rise to tree- and loop-level contributions to spin-independent scattering cross section at the direct detection experiments such as XENON and LUX-ZEPLIN which can be probed in their future upgrades. By choosing suitable Froggatt-Nielsen charges for the fermions, we also generate the mass spectrum of the SM neutrinos via the Type-I seesaw mechanism. Flavor-changing neutral current processes, such as radiative lepton decay, meson mixing, and top-quark decay remain the most constraining channels and provide testability for this minimal setup that addresses several major shortcomings of the SM.

    hep-phJCAP(2023)·5 citations
21. 21*

    Leading two-loop corrections to the Higgs di-photon decay in the Inert Doublet Model

    Masashi Aiko🇯🇵 · Johannes Braathen🇩🇪 · Shinya Kanemura🇯🇵

    Leading two-loop contributions to the di-photon decay of the Higgs boson are evaluated for the first time in the Inert Doublet Model (IDM). We employ for this calculation the Higgs low-energy theorem, meaning that we obtain corrections to the Higgs decay process by taking Higgs-field derivatives of the leading two-loop contributions to the photon self-energy. Specifically, we have included corrections involving inert BSM Higgs bosons and gauge bosons, as well as external-leg contributions involving inert scalars, gauge bosons and fermions. Our calculation has been performed with a full on-shell renormalization, and in the gauge-less limit. Moreover, we performed two independent calculations, using the background-field method and the pinch technique, in order to apply the Higgs low-energy theorem consistently, and found full agreement between the two calculations. We investigate our results numerically in two scenarios of the IDM: one with a light dark matter (DM) candidate (Higgs resonance scenario), and another with all additional scalars heavy (heavy Higgs scenario). In both cases, we find that the inclusion of two-loop corrections qualitatively modifies the behavior of the decay width, compared with the one-loop ($i.e.$ leading) order, and that they increase the deviation from the Standard Model. Furthermore, we demonstrate that the inclusion of the newly-computed two-loop corrections is essential to reliably interpret the observation or non-observation of a deviation in the Higgs di-photon decay width at current and future colliders.

    hep-phEPJC(2025)·33 citations
22. 22*

    Renormalized equations of motions for scalars and fermions in the 2PI formalism

    A. Banik🇩🇪 · H. Hinrichsen🇩🇪 · W. Porod🇩🇪

    We present on shell-scheme for the 2PI formalism with a particular focus on the renormalized equations of motion. We first revisit the so-called Hartree approximation where we give the counterterms for both the broken and unbroken phase. Moreover, we give explicit formulas for the renormalized three- and four-point functions in the broken phase. We then turn to the sunset approximation, with only scalars and then including fermions. We give explicit formulas for the wavefunction and mass counterterms. Moreover, we show that, in particular, the two-point functions can be obtained numerically in a fast converging scheme even for large couplings of order one.

    hep-phhep-thInt.J.Mod.Phys.A(2024)·2 citations
23. 23*

    A general algorithm to build mixed real and virtual antenna functions for higher-order calculations

    Oscar Braun-White🇬🇧 · Nigel Glover🇬🇧 · Christian T Preuss🇨🇭

    The antenna-subtraction technique has demonstrated remarkable effectiveness in providing next-to-next-to-leading order in ${\alpha }_s$ (NNLO) predictions for a wide range of processes relevant for the Large Hadron Collider. In a previous paper [1], we demonstrated how to build real-radiation antenna functions for any number of real emissions directly from a specified list of unresolved limits. Here, we extend this procedure to the mixed case of real and virtual radiation, for any number of real and virtual emissions. A novel feature of the algorithm is the requirement to match the antenna constructed with the correct unresolved limits to the other elements of the subtraction scheme. We discuss how this can be achieved and provide a full set of real-virtual NNLO antenna functions (together with their integration over the final-final unresolved phase space). We demonstrate that these antennae can be combined with the real-radiation antennae of Ref. [1] to form a consistent NNLO subtraction scheme that cancels all explicit and implicit singularities at NNLO. We anticipate that the improved antenna functions should be more amenable to automation, thereby making the construction of subtraction terms for more complicated processes simpler at NNLO.

    hep-phJHEP(2023)·24 citations
24. 24*

    Role of QCD in moduli stabilization during inflation and axion dark matter

    Ryuichiro Kitano🇯🇵 · Motoo Suzuki🇺🇸 · Wen Yin🇯🇵

    Ignorance of the initial condition for the axion dynamics in the early Universe has led us to consider an $O(1)$ valued initial amplitude, and that prefers the decay constant, $F_a$, of the QCD axion to be an intermediate scale such as $10^{12}$ GeV in order to explain the dark matter abundance. We explore a cosmological scenario of $F_a$ being much larger than $10^{12}$ GeV by considering the axion and moduli dynamics during inflation to set the initial amplitude. We show that if the volume moduli (radion) of the extra-dimension is stabilized mainly by the QCD contribution to the moduli potential during inflation, the QCD axion with the string-scale decay constant obtains a mass around the inflationary Hubble parameter. This means that the axion rolls down to the $\theta =0$ minimum during the inflation realizing almost vanishing initial amplitude, and the inflationary quantum fluctuation can be the dominant source of the current number density of axions. We find natural parameter regions where the axion explains the cold dark matter of the Universe, while the constraint on the isocurvature perturbation is avoided. The presence of the axion miniclusters or axion stars are predicted in a wide range of parameters, including the one explains the Subaru-HCS microlensing event.

    hep-phastro-ph.COJHEP(2023)·8 citations
25. 25*

    Seeing Beauty in the Quark-Gluon Plasma with Energy Correlators

    Carlota Andres🇫🇷 · Fabio Dominguez🇪🇸 · Jack Holguin🇫🇷 · Cyrille Marquet🇫🇷 · Ian Moult🇺🇸

    Heavy quarks created in heavy-ion collisions serve as an excellent probe of the produced quark-gluon plasma (QGP). The radiation pattern of jets formed from heavy quarks as they traverse the QGP exhibits a particularly interesting structure due to the interplay of two competing effects: the suppression of small-angle radiation, also known as the ``dead-cone'' effect, and the enhancement of emitted gluons by medium-induced radiation. In this Letter, we propose a new observable, based on the energy correlator approach to jet substructure, which will allow us to disentangle the two scales associated to these two phenomena and to determine under which conditions the dead-cone is filled by medium-induced radiation. Combined with the forthcoming high-statistics measurements of heavy-flavor jets, this work provides a novel tool to unravel the dynamics of the QGP.

    hep-phhep-exnucl-exnucl-thPRD(2024)·60 citations
26. 26*

    The Morphology of Exciting Dark Matter and the Galactic 511 keV Signal

    Christopher V. Cappiello🇨🇦 · Michael Jafs🇨🇦 · Aaron C. Vincent🇨🇦

    We study the morphology of the 511 keV signal that could be produced by exciting dark matter (XDM) in the Milky Way. In this model, collisions between dark matter particles excite the dark matter to a state that can then decay back to the ground state, releasing an electron-positron pair. These electrons and positrons would then annihilate, producing 511 keV photons that could explain the 511 keV signal seen by INTEGRAL at the Galactic Center. We compare the resulting flux with the most recent INTEGRAL data, performing the first full statistical analysis of the exciting dark matter model. We focus on exciting dark matter in the mass and cross section ranges 100 GeV $\lesssim m_{\chi }\lesssim$ 3 TeV and $10^{-19}$ cm${}^3$ s${}^{-1}\lesssim ⟨\sigma v⟩\lesssim 10^{-16}$ cm${}^3$ s${}^{-1}$. We show that exciting dark matter can provide a significantly better fit than the simpler case of annihilating dark matter, with $\Delta {\chi }^2>16$ for all but one of the density profiles we consider.

    hep-phastro-ph.HEJCAP(2023)·12 citations
27. 27*

    Large Neutrino Secret Interactions, Small Impact on Supernovae

    Damiano F. G. Fiorillo🇩🇰 · Georg Raffelt🇩🇪 · Edoardo Vitagliano🇮🇱

    When hypothetical neutrino secret interactions ($\nu$SI) are large, they form a fluid in a supernova (SN) core, flow out with sonic speed, and stream away as a fireball. For the first time, we tackle the complete dynamical problem and solve all steps, systematically using relativistic hydrodynamics. The impact on SN physics and the neutrino signal is remarkably small. For complete thermalization within the fireball, the observable spectrum changes in a way that is independent of the coupling strength. One potentially large effect beyond our study is quick deleptonization if $\nu$SI violate lepton number. By present evidence, however, SN physics leaves open a large region in parameter space, where laboratory searches and future high-energy neutrino telescopes will probe $\nu$SI.

    hep-phastro-ph.HEPRL(2024)·63 citations
28. 28*

    Renormalisation group analysis of scalar Leptoquark couplings addressing flavour anomalies: emergence of lepton-flavour universality

    Marco Fedele🇩🇪 · Felix Wuest🇩🇪 · Ulrich Nierste🇩🇪

    Leptoquarks with masses between 2 TeV and 50 TeV are commonly invoked to explain deviations between data and Standard-Model (SM) predictions of several observables in the decays $b\to c\tau \bar{\nu }$ and $b\to s{\ell }^{+}{\ell }^{-}$ with $\ell =e,\mu$. While Leptoquarks appear in theories unifying quarks and leptons, the corresponding unification scale $M_{QLU}$ is typically many orders of magnitude above this mass range. We study the case that the mass gap between the electroweak scale and $M_{QLU}$ is only populated by scalar Leptoquarks and SM particles, restricting ourselves to scenarios addressing the mentioned flavour anomalies, and determine the renormalisation-group evolution of Leptoquark couplings to fermions below $M_{QLU}$. In the most general case, we consider three SU(2) triplet Leptoquarks $S_3^{\ell }$, $\ell =e,\mu ,\tau$, which couple quark doublets to the lepton doublet $({\nu }_{\ell },{\ell }^{-})$ to address the $b\to s{\ell }^{+}{\ell }^{-}$ anomalies. In this case, we find a scenario in which the Leptoquark couplings to electrons and muons are driven to the same infrared fixed point, so that lepton flavour universality emerges dynamically. However, the corresponding fixed point for the couplings to taus is necessarily opposite in sign, leading to a unique signature in $b\to s{\tau }^{+}{\tau }^{-}$. For $b\to c\tau \bar{\nu }$ we complement these with either an SU(2) singlet $S_1^{\tau }$ or doublet $R_2^{\tau }$ and study further the cases that also these Leptoquarks come in three replicas. The fixed point solutions for the $S_3^{\ell }$ couplings explain the $b\to s{\ell }^{+}{\ell }^{-}$ data for $S_3^{e,\mu }$ masses around 10 TeV. $b\to c\tau \bar{\nu }$ data can only be fully explained by couplings exceeding their fixed-point values and evolving into Landau poles at high energies, so that one can place an upper bound on $M_{QLU}$ between $10^8$ and $10^{11}$ GeV.

    hep-phhep-exJHEP(2023)·6 citations
29. 29*

    Supernova Emission of Secretly Interacting Neutrino Fluid: Theoretical Foundations

    Damiano F. G. Fiorillo🇩🇰 · Georg Raffelt🇩🇪 · Edoardo Vitagliano🇮🇱

    Neutrino-neutrino scattering could have a large secret component that would turn neutrinos within a supernova (SN) core into a self-coupled fluid. Neutrino transport within the SN core, emission from its surface, expansion into space, and the flux spectrum and time structure at Earth might all be affected. We examine these questions from first principles. First, diffusive transport differs only by a modified spectral average of the interaction rate. We next study the fluid energy transfer between a hot and a cold blackbody surface in plane-parallel and spherical geometry. The key element is the decoupling process within the radiating bodies, which themselves are taken to be isothermal. For a zero-temperature cold plate, mimicking radiation into free space by the hot plate, the energy flux is 3--4\% smaller than the usual Stefan-Boltzmann Law. The fluid energy density just outside the hot plate is numerically 0.70 of the standard case, the outflow velocity is the speed of sound $v_s=c/\sqrt{3}$, conspiring to a nearly unchanged energy flux. Our results provide the crucial boundary condition for the expansion of the self-interacting fluid into space, assuming an isothermal neutrino sphere. We also derive a dynamical solution, assuming the emission suddenly begins at some instant. A neutrino front expands in space with luminal speed, whereas the outflow velocity at the radiating surface asymptotically approaches $v_s$ from above. Asymptotically, one thus recovers the steady-state emission found in the two-plate model. A sudden end to neutrino emission leads to a fireball with constant thickness equal to the duration of neutrino emission.

    hep-phastro-ph.HEPRD(2024)·51 citations
30. 30*

    Patchy Screening of the CMB from Dark Photons

    Dalila Pîrvu🇨🇦 · Junwu Huang🇨🇦 · Matthew C. Johnson🇨🇦

    We study anisotropic (patchy) screening induced by the resonant conversion of cosmic microwave background (CMB) photons into dark-sector massive vector bosons (dark photons) as they cross non-linear large scale structure (LSS). Resonant conversion takes place through the kinetic mixing of the photon with the dark photon, one of the simplest low energy extensions to the Standard Model. In the early Universe, resonant conversion can occur when the photon plasma mass, obtained as the photon propagates through the ionized interstellar and intergalactic media, matches the dark photon mass. After the epoch of reionization, resonant conversion occurs mainly in the ionized gas that occupies virialized dark matter halos, for a range of dark photon masses between $10^{-13}\mathrm{eV}\lesssim m_{{\mathrm{A}}^{\prime }}\lesssim 10^{-11}\mathrm{eV}$. This leads to new CMB anisotropies that are correlated with LSS, which we refer to as patchy dark screening, in analogy with anisotropies from Thomson screening. Its unique frequency dependence allows it to be distinguished from the blackbody CMB. In this paper, we use a halo model approach to predict the imprint of dark screening on the CMB temperature and polarization anisotropies, as well as their correlation with LSS. We then examine the two- and three-point correlation functions of the dark-screened CMB, as well as correlation functions between CMB and LSS observables, to project the sensitivity of future measurements to the kinetic mixing parameter and dark photon mass. We demonstrate that an analysis with existing CMB data can improve upon current constraints on the kinetic mixing parameter by two orders of magnitude with the two-point correlation functions, while data from upcoming CMB experiments and LSS surveys can further improve the reach by another order of magnitude with two- and three-point correlation functions.

    hep-phastro-ph.COJCAP(2024)·24 citations
31. 31*

    AutoSourceID-Classifier. Star-Galaxy Classification using a Convolutional Neural Network with Spatial Information

    F. Stoppa · S. Bhattacharyya🇸🇮 · R. Ruiz de Austri🇪🇸 · P. Vreeswijk · S. Caron🇳🇱 · G. Zaharijas🇸🇮 · S. Bloemen · G. Principe🇮🇹 · D. Malyshev · V. Vodeb🇸🇮 · P. J. Groot · E. Cator · G. Nelemans

    Aims. Traditional star-galaxy classification techniques often rely on feature estimation from catalogues, a process susceptible to introducing inaccuracies, thereby potentially jeopardizing the classification's reliability. Certain galaxies, especially those not manifesting as extended sources, can be misclassified when their shape parameters and flux solely drive the inference. We aim to create a robust and accurate classification network for identifying stars and galaxies directly from astronomical images. By leveraging convolutional neural networks (CNN) and additional information about the source position, we aim to accurately classify all stars and galaxies within a survey, particularly those with a signal-to-noise ratio (S/N) near the detection limit. Methods. The AutoSourceID-Classifier (ASID-C) algorithm developed here uses 32x32 pixel single filter band source cutouts generated by the previously developed ASID-L code. ASID-C utilizes CNNs to distinguish these cutouts into stars or galaxies, leveraging their strong feature-learning capabilities. Subsequently, we employ a modified Platt Scaling calibration for the output of the CNN. This technique ensures that the derived probabilities are effectively calibrated, delivering precise and reliable results. Results. We show that ASID-C, trained on MeerLICHT telescope images and using the Dark Energy Camera Legacy Survey (DECaLS) morphological classification, outperforms similar codes like SourceExtractor. ASID-C opens up new possibilities for accurate celestial object classification, especially for sources with a S/N near the detection limit. Potential applications of ASID-C, like real-time star-galaxy classification and transient's host identification, promise significant contributions to astronomical research.

    ↳ astro-ph.IMhep-phAstron.Astrophys.(2023)·4 citations
32. 32*

    Study on the Contribution of Positronium and ${\pi }^0$ Mesons to Casimir Force

    Cong Li🇨🇳

    There is a Casimir force between two metal plates. It is generally believed that the Casimir force is mediated by virtual photons in a vacuum, which correspond to the massless intermediate particles used in our theoretical calculations. Studies have shown that not only virtual photons in a vacuum, but also other virtual particles that have masses. The lightest chargeless virtual particles with mass are positronium (1 MeV) and ${\pi }^0$ mesons (135 MeV). This paper primarily focuses on studying the corrections to the Casimir force caused by positronium and ${\pi }^0$ mesons. Especially when the distance between the two plates is on the order of $1/m_{positronium}$ , the contribution of positronium becomes significant, and on the order of $1/m_{{\pi }^0}$ , the contribution of the ${\pi }^0$ meson becomes significant. We hope that the calculation results can reduce the error in the theoretical calculation of the Casimir force when the distance between the plates is large and provide significant corrections when the distance is small.

    ↳ quant-phhep-ph0 citations
33. 33*

    Observation of the decay $J/\psi \to e^{+}{e}^{-}\eta (1405)$ with $\eta (1405)\to {\pi }^0{f}_0(980)$

    BESIII Collaboration: M. Ablikim · M. N. Achasov · P. Adlarson · X. C. Ai · R. Aliberti · A. Amoroso · M. R. An · Q. An · Y. Bai · O. Bakina · I. Balossino · Y. Ban and 613 other authors

    Using a data sample of $(10087\pm 44)\times 10^6$ $J/\psi$ events collected by the BESIII detector in 2009, 2012, 2018 and 2019, the electromagnetic Dalitz process $J/\psi \to e^{+}{e}^{-}\eta (1405)$ is observed via the decay $\eta (1405)\to {\pi }^0{f}_0(980)$, $f_0(980)\to {\pi }^{+}{\pi }^{-}$, with a significance of about $9.6\sigma$. The branching fraction of this decay is measured to be $\mathcal{B}(J/\psi \to e^{+}{e}^{-}{\pi }^0\eta (1405)\to e^{+}{e}^{-}{\pi }^0{f}_0(980)\to e^{+}{e}^{-}{\pi }^0{\pi }^{+}{\pi }^{-})=(2.02\pm 0.24(stat.)\pm 0.09(syst.))\times 10^{-7}$. The branching-fraction ratio $\mathcal{B}(J/\psi \to e^{+}{e}^{-}\eta (1405))$/$\mathcal{B}(J/\psi \to \gamma \eta (1405))$ is determined to be $(1.35\pm 0.19(stat.)\pm 0.06(syst.))\times 10^{-2}$. Furthermore, an $e^{+}{e}^{-}$ invariant-mass dependent transition form factor of $J/\psi \to e^{+}{e}^{-}\eta (1405)$ is presented for the first time. The obtained result provides input for different theoretical models, and is valuable for the improved understanding the intrinsic structure of the $\eta (1405)$ meson.

    ↳ hep-exhep-phPRD(2024)·3 citations
34. 34*

    Elliptic and triangular flow of charmonium states in heavy ion collisions

    Sungtae Cho🇰🇷

    We study the elliptic and triangular flow of charmonium states, or $J/\psi$, $\psi (2S)$, and ${\chi }_c(1P)$ mesons in heavy ion collisions. Starting from the evaluation of charmonia transverse momentum distributions and yields, we calculate elliptic and triangular flow of charmonium states based on the coalescence model. We show that the internal structure, or the wave function distribution of charmonium states plays a significant role, especially when charmonium states are produced by charm quark recombination, leading to the transverse momentum distribution of the $\psi (2S)$ meson as half large as that of the $J/\psi$ meson. We also consider the dependence of the elliptic and triangular flow of charmonium states on internal structures of charmonium states, and find that the wave function effects as well as feed-down contributions are averaged out for elliptic and triangular flow, resulting in similar elliptic and triangular flow for all charmonium states. We investigate further the elliptic and triangular flow of charmonium states at low transverse momentum region, and also discuss the quark number scaling of elliptic and triangular flow for charmonium states.

    ↳ nucl-thhep-phPRC(2024)·4 citations
35. 35*

    The state of the dark energy equation of state circa 2023

    Luis A. Escamilla🇬🇧 · William Giarè🇬🇧 · Eleonora Di Valentino🇬🇧 · Rafael C. Nunes🇧🇷 · Sunny Vagnozzi🇮🇹

    We critically examine the state of current constraints on the dark energy (DE) equation of state (EoS) $w$. Our study is motivated by the observation that, while broadly consistent with the cosmological constant value $w=-1$, several independent probes appear to point towards a slightly phantom EoS ($w\sim -1.03$) which, if confirmed, could have important implications for the Hubble tension. We pay attention to the apparent preference for phantom DE from Planck Cosmic Microwave Background (CMB) data alone, whose origin we study in detail and attribute to a wide range of (physical and geometrical) effects. We deem the combination of Planck CMB, Baryon Acoustic Oscillations, Type Ia Supernovae, and Cosmic Chronometers data to be particularly trustworthy, inferring from this final consensus dataset $w=-1.013_{-0.043}^{+0.038}$, in excellent agreement with the cosmological constant value. Overall, despite a few scattered hints, we find no compelling evidence forcing us away from the cosmological constant (yet).

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2024)·122 citations
36. 36*

    Reexamining charm versus bottom quark energy loss inside a color-deconfined medium

    Yichao Dang🇨🇳 · Wen-Jing Xing🇨🇳 · Shanshan Cao🇨🇳 · Guang-You Qin🇨🇳

    The general intuition that heavier partons suffer weaker energy loss inside a quark-gluon plasma (QGP) medium is critically re-examined. Within a linear Boltzmann transport model that includes both Yukawa and string types of interactions between heavy quarks and the QGP, we find that while the radiative energy loss is suppressed by the parton mass, heavier partons can experience stronger string potential scatterings with the medium. Their competition may result in less energy loss of bottom quarks than charm quarks at low transverse momentum ($p_{\mathrm{T}}$) but an inverse order at high $p_{\mathrm{T}}$. Our model calculation shows a weaker nuclear modification on bottom particles than charm particles at low $p_{\mathrm{T}}$, as observed by both RHIC and LHC experiments, but predicts an opposite hierarchy at high $p_{\mathrm{T}}$. A larger momentum space transport coefficient ($\hat{q}$) and a smaller spatial diffusion coefficient ($D_{\mathrm{s}}$) are found for bottom quarks than for charm quarks.

    ↳ nucl-thhep-phnucl-exPRC(2024)·9 citations
37. 37*

    Probing the equation of state of the early Universe with pulsar timing arrays

    Lang Liu🇨🇳 · Zu-Cheng Chen🇨🇳 · Qing-Guo Huang🇨🇳

    The recently released data by pulsar timing array (PTA) collaborations have amassed substantial evidence corroborating the existence of a stochastic signal consistent with a gravitational-wave background at frequencies around the nanohertz regime. We investigate the situation in which the PTA signal originates from scalar-induced gravitational waves~(SIGWs), which serves as a valuable tool to probe the equation of state parameter $w$ during the Universe's early stages. The joint consideration of the PTA data from the NANOGrav 15-year data set, PPTA DR3, and EPTA DR2 yields that $w=0.60_{-0.39}^{+0.32}$ (median + $90\%$ credible interval), indicating a period of condensate domination at the production of SIGWs is allowed by the data. Moreover, the data also supports radiation domination ($w=1/3$) within the $90\%$ credible interval. We also impose an upper bound on the reheating temperature that $T_{\mathrm{rh}}\lesssim 0.2\mathrm{GeV}$ and the constraint on $w$ reveals valuable information on the inflationary potential and the dynamics at the end of inflation.

    ↳ astro-ph.COgr-qchep-phJCAP(2023)·127 citations
38. 38*

    Confronting axial-vector form factor from lattice QCD with MINERvA antineutrino-proton data

    Oleksandr Tomalak🇺🇸 · Rajan Gupta🇺🇸 · Tanmoy Bhattacharya🇺🇸

    We compare recent MINERvA antineutrino-hydrogen charged-current measurements to phenomenological predictions of the axial-vector form factor based on fits to all available electron scattering and deuterium bubble-chamber data and to representative lattice-QCD (LQCD) determination by the PNDME Collaboration. While there is $1$--$2\sigma$ agreement in the cross section with MINERvA data for each bin in $Q^2$, we identify three regions with different relevance and opportunity for LQCD predictions. For $Q^2\lesssim 0.2{\mathrm{GeV}}^2$, the phenomenological extractions have large number of data points and LQCD is competitive, while MINERvA data have large errors. For $0.2{\mathrm{GeV}}^2\lesssim Q^2\lesssim 1{\mathrm{GeV}}^2$, LQCD is competitive with the MINERvA determination, and both give values larger than from phenomenological extraction. For $Q^2>1{\mathrm{GeV}}^2$, the MINERvA data are the most precise. Our analysis indicates that with improving precision of MINERvA-like experiments and LQCD data, the uncertainty in the nucleon axial-vector form factor will be steadily reduced.

    ↳ hep-lathep-exhep-phnucl-ex+1PRD(2023)·27 citations
39. 39*

    Lattice quantum chromodynamics at large isospin density: 6144 pions in a box

    Ryan Abbott🇺🇸 · William Detmold🇺🇸 · Fernando Romero-López🇺🇸 · Zohreh Davoudi🇺🇸 · Marc Illa🇺🇸 · Assumpta Parreño🇪🇸 · Robert J. Perry🇪🇸 · Phiala E. Shanahan🇺🇸 · Michael L. Wagman🇺🇸

    We present an algorithm to compute correlation functions for systems with the quantum numbers of many identical mesons from lattice quantum chromodynamics (QCD). The algorithm is numerically stable and allows for the computation of $n$-pion correlation functions for $n\in \{1,\dots ,N\}$ using a single $N\times N$ matrix decomposition, improving on previous algorithms. We apply the algorithm to calculations of correlation functions with up to 6144 ${\pi }^{+}$s using two ensembles of gauge field configurations generated with quark masses corresponding to a pion mass $m_{\pi }=170$ MeV and spacetime volumes of $(4.4^3\times 8.8){\mathrm{fm}}^4$ and $(5.8^3\times 11.6){\mathrm{fm}}^4$. We also discuss statistical techniques for the analysis of such systems, in which the correlation functions vary over many orders of magnitude. In particular, we observe that the many-pion correlation functions are well approximated by log-normal distributions, allowing the extraction of the energies of these systems. Using these energies, the large-isospin-density, zero-baryon-density region of the QCD phase diagram is explored. A peak is observed in the energy density at an isospin chemical potential ${\mu }_I\sim 1.5m_{\pi }$, signalling the transition into a Bose-Einstein condensed phase. The isentropic speed of sound in the medium is seen to exceed the ideal-gas (conformal) limit ($c_s^2\le 1/3$) over a wide range of chemical potential before falling towards the asymptotic expectation at ${\mu }_I\sim 15m_{\pi }$. These, and other thermodynamic observables, indicate that the isospin chemical potential must be large for the system to be well described by an ideal gas or perturbative QCD.

    ↳ hep-lathep-phnucl-thPRD(2023)·80 citations
40. 40*

    Galaxy bias renormalization group

    Henrique Rubira🇩🇪 · Fabian Schmidt🇩🇪

    The effective field theory of large-scale structure allows for a consistent perturbative bias expansion of the rest-frame galaxy density field. In this work, we present a systematic approach to renormalize galaxy bias and stochastic parameters using a finite cutoff scale $\Lambda$. We derive the differential equations of the Wilson-Polchinski renormalization group that describe the evolution of the finite-scale bias parameters with $\Lambda$, analogous to the $\beta$-function running in QFT. We further provide the connection between the finite-cutoff scheme and the renormalization procedure for $n$-point functions that has been used as standard in the literature so far; some inconsistencies in the treatment of renormalized bias in current EFT analyses are pointed out as well. The fixed-cutoff scheme allows us to predict, in a principled way, the finite part of loop contributions which is due to perturbative modes and which, in the standard renormalization approach, is absorbed into counterterms. We expect that this will allow for the robust extraction of (a yet-to-be-determined amount of) additional cosmological information from galaxy clustering, both when using field-level techniques and $n$-point functions.

    ↳ astro-ph.COhep-phhep-thJCAP(2024)·27 citations
41. 41*

    News from the Swampland -- Constraining string theory with astrophysics and cosmology

    Nils Schöneberg🇪🇸 · Léo Vacher🇫🇷 · J. D. F. Dias🇵🇹 · Martim M. C. D. Carvalho🇵🇹 · C. J. A. P. Martins🇵🇹

    Our current best guess for a unified theory of gravitation and quantum field theory (string theory) generically predicts a set of requirements for a consistently quantized theory, the Swampland criteria. Refined versions of these criteria have recently been shown to be in mild tension with cosmological observations. We summarize the status of the current impact of and constraints on the Swampland conjectures from cosmology, and subject a variety of dark energy quintessence models to recently released cosmological datasets. We find that instead of tightening the tension, the new data allows for slightly more freedom in the Swampland criteria. We further demonstrate that if there is no theoretical argument made to prevent interactions of the moduli fields with the electromagnetic sector, a novel fine-tuning argument arises from the extremely tight current constraints on such interactions. Finally, we conclude with a cautionary tale on model-independent reconstructions of the Swampland criteria from expansion rate data.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2023)·33 citations
42. 42*

    Chiral anomaly and dynamos from inhomogeneous chemical potential fluctuations

    Jennifer Schober🇨🇭 · Igor Rogachevskii🇮🇱 · Axel Brandenburg🇸🇪

    In the standard model of particle physics, the chiral anomaly can occur in relativistic plasmas and plays a role in the early Universe, protoneutron stars, heavy-ion collisions, and quantum materials. It gives rise to a magnetic instability if the number densities of left- and right-handed electrically charged fermions are unequal. Using direct numerical simulations, we show this can result just from spatial fluctuations of the chemical potential, causing a chiral dynamo instability, magnetically driven turbulence, and ultimately a large-scale magnetic field through the magnetic alpha effect.

    ↳ physics.plasm-phastro-ph.COhep-phphysics.flu-dynPRL(2024)·8 citations
43. 43*

    Dynamical induced quark spin polarization by magnetic field at the early stage of heavy-ion collisions

    Anping Huang🇨🇳 · Zilin Yuan🇨🇳 · Mei Huang🇨🇳

    We present a comprehensive analysis of the dynamic process of quark spin polarization induced by magnetic fields at the pre-thermal stage in heavy-ion collisions by using the recently developed theoretical tool of chiral kinetic theory. Our findings demonstrate that the spin polarization of quarks is highly sensitive to the interactions between quarks. These interactions can delay the decay of early spin polarization vector while accelerating the decay of later spin polarization vector. Specifically, our simulations show the detailed process of how magnetic fields polarize quarks within the fireball and reveal that quark interactions lead to an acceleration effect on the average spin. Notably, the fireball of quark-gluon plasma (QGP) in its early stages exhibits an incomplete electromagnetic response effect, which differs from the response predicted by Lenz's law. This discrepancy arises from quantum corrections involving the interactions between quark spin and electromagnetic fields.

    ↳ nucl-thhep-phPRD(2024)·1 citation
44. 44*

    The Giant Radio Array for Neutrino Detection (GRAND) Collaboration -- Contributions to the 38th International Cosmic Ray Conference (ICRC 2023)

    GRAND Collaboration: Rafael Alves Batista🇪🇸 · Aurélien Benoit-Lévy🇫🇷 · Teresa Bister🇳🇱 · Mauricio Bustamante🇩🇰 · Yiren Chen🇨🇳 · LingMei Cheng🇨🇳 · Simon Chiche🇫🇷 · Jean-Marc Colley🇫🇷 · Pablo Correa🇫🇷 · Nicoleta Cucu Laurenciu🇳🇱 · Zigao Dai🇨🇳 · Beatriz de Errico🇧🇷 and 86 other authors

    The Giant Radio Array for Neutrino Detection (GRAND) is an envisioned observatory of ultra-high-energy particles of cosmic origin, with energies in excess of 100 PeV. GRAND uses large surface arrays of autonomous radio-detection units to look for the radio emission from extensive air showers that are triggered by the interaction of ultra-high-energy cosmic rays, gamma rays, and neutrinos in the atmosphere or underground. In particular, for ultra-high-energy neutrinos, the future final phase of GRAND aims to be sensitive enough to discover them in spite of their plausibly tiny flux. Presently, three prototype GRAND radio arrays are in operation: GRANDProto300, in China, GRAND@Auger, in Argentina, and GRAND@Nancay, in France. Their goals are to field-test the design of the radio-detection units, understand the radio background to which they are exposed, and develop tools for diagnostic, data gathering, and data analysis. This list of contributions to the 38th International Cosmic Ray Conference (ICRC 2023) presents an overview of GRAND, in its present and future incarnations, and a look at the first data collected by GRANDProto13, the first phase of GRANDProto300.

    ↳ hep-exastro-ph.HEastro-ph.IMhep-ph4 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.