HEP Phenomenology·hep-ph
68 papers—51 primary·17 cross-listed·reconstructed*
This brief summary targets feebly interacting massive particles, FIMPs, which are interesting candidates for dark matter. The cosmic history of FIMP dark matter often leads to predictions of long-lived mediator particles at laboratory experiments. I point out the role of the LHC in searching for such particles and sketch its complementarity with low-energy experiments.
We present mass spectrum and magnetic moments of the states, where and . We solve four-body Schrödinger equation with a quark potential model by using diffusion Monte Carlo (DMC) method. The quark potential is based on the Coulomb, confinement and spin-spin interaction terms. We find mass and magnetic moment of the state as and , respectively. We also find the mass and magnetic moment of as and , respectively. We find some bound state candidates of doubly heavy tetraquark systems with , , , and . We compare our results with other approaches in the literature.
Alon E. Faraggi🇬🇧 · Mark D. Goodsell🇫🇷
We introduce a phenomenological model for a string-derived scenario, and study its predictions for the mass of the W boson. In the process, we compare it to collider constraints for both pair-produced particles, Higgs boson properties, and searches. We also describe the implementation of new tools in the scanning code BSMArt.
Arturo de Giorgi🇪🇸 · Luca Merlo🇪🇸 · Xavier Ponce Díaz🇮🇹 · Stefano Rigolin🇮🇹
A convincing explanation of the smallness of neutrino masses is represented by the Type-I Seesaw mechanism, where the two measured neutrino mass differences can be generated by introducing at least two right-handed neutrinos. In an ultraviolet complete model, it is possible to dynamically generate the heavy Majorana scale through the spontaneous symmetry breaking of a global Abelian symmetry and the most economical realisation consists in coupling the two exotic neutral leptons to a singlet complex scalar field. The associated Goldstone boson is often dubbed as Majoron, which may achieve a non-vanishing mass by means of a small term that explicitly breaks the Abelian symmetry. In a generic model, the neutrino and Majoron mass generation mechanisms are completely uncorrelated. In this paper, instead, we reduce the landscape of possible models proposing a unique, minimal and predictive framework in which these two types of masses are strictly tied and arise from the same source. Bounds from various terrestrial and astrophysical experiments are discussed.
Andreas Papaefstathiou🇺🇸 · Gilberto Tetlalmatzi-Xolocotzi🇫🇷
We investigate multi-Higgs boson production at proton colliders, in a framework involving anomalous interactions, focusing on triple Higgs boson production. We consider modifications to the Higgs boson self-couplings, to the Yukawa interactions, as well as new contact interactions of Higgs bosons with either quarks or gluons. To this end, we have developed a MadGraph5_aMC@NLO loop model, publicly available at https://gitlab.com/apapaefs/multihiggs_loop_sm, designed to incorporate the relevant operators in the production of multiple Higgs bosons (and beyond). We have performed cross section fits at various energies over the anomalous interactions, and have derived constraints on the most relevant anomalous coefficients, through detailed phenomenological analyses at proton-proton collision energies of 13.6 TeV and 100 TeV, through the 6 -jet final state.
Zanpeng Yin🇯🇵 · Daisuke Jido🇯🇵
We study the theoretical structure of compositeness with explicit energy dependence, and find a possible explanation for the difficulty in the interpretation of compositeness of deuteron. Compositeness of deuteron is calculated as larger than one in many methods like weak-binding limit. Even though it is widely assumed that the energy dependence in interaction always comes from other states, which we call surjective interpretation, we find that the outcome of deuteron may suggest a violation of surjective interpretation. We directly perform numerical and perturbative calculations of deuteron compositeness. It is concluded that if the energy dependent part of interaction contributes to attraction, compositeness is likely to be enhanced from unity. We discuss the indications of this outcome and the model dependence of compositeness. We propose a straightforward extension and a thorough revise on the formalism of compositeness with field theory considerations.
Lata Thakur🇰🇷 · Yuji Hirono🇰🇷
We study the interplay of non-equilibrium properties of a quark-gluon plasma (QGP) and heavy quarkonia. For this purpose, we compute the quarkonium spectral functions in a bulk-viscous QGP. We take into account the bulk viscous nature of the medium by modifying the distribution functions of thermal quarks and gluons. This modification affects the dielectric permittivity, which is used to calculate the in-medium heavy quark potential. With this modified complex potential, we calculate the quarkonium spectral functions and extract their physical properties. We discuss the impact of bulk viscosity on quarkonia properties such as decay widths and binding energies. We also estimate the relative production yield of to and discuss the bulk viscous effects on it.
Bo Wang🇨🇳 · Kan Chen🇨🇳 · Lu Meng🇩🇪 · Shi-Lin Zhu🇨🇳
We investigate the mass spectrum of the molecular pentaquarks composed of a baryon and a meson. We establish the underlying relations among the near-threshold interactions of the molecular tetraquark and pentaquark systems. We find the existence of the molecule candidates in the , , and systems indicates a substantial presence of the hadronic molecules in the {\it heavy} baryon plus {\it heavy} meson systems ({\it heavy} refers to the hadrons with the and/or quarks). We make an exhaustive prediction of the possible bound/virtual molecular states in the systems: , , , , , , , , , , , , , , , , , , , . Hunting for the predicted states in experiments will significantly deepen our understanding of the formation mechanism of the hadronic molecules, and shed light on the manifestation of flavor symmetry in the low-energy residual strong interactions.
Kensuke Akita🇰🇷 · Sang Hui Im🇰🇷 · Mehedi Masud🇰🇷 · Seokhoon Yun🇰🇷
Light hypothetical particles with masses up to can be produced in the core of supernovae. Their subsequent decays to neutrinos can produce a flux component with higher energies than the standard flux. We study the impact of heavy neutral leptons, bosons, in particular and gauge bosons, and majorons coupled to neutrinos flavor-dependently. We obtain new strong limits on these particles from no events of high-energy SN 1987A neutrinos and their future sensitivities from observations of galactic supernova neutrinos.
B.I. Ermolaev🇷🇺 · S.I. Troyan🇷🇺
Dispersion Relations (DR) are known to be a powerful instrument for studying scattering amplitudes. In particular, they often apply to calculations in Perturbative QCD and Standard Model. We argue that applying DR to amplitudes with double-logarithmic (DL) contributions should be done with a proper caution because DL terms are often infrared-divergent. Ignoring this circumstance leads to incorrect results. As an example of such situation, we consider applying DR to decays of on-shell W and Z -bosons into fermion pairs in the Double-Logarithmic Approximation
Melina Filzinger🇩🇪 · Ashlee R. Caddell🇦🇺 · Dhruv Jani🇦🇺 · Martin Steinel🇩🇪 · Leonardo Giani🇦🇺 · Nils Huntemann🇩🇪 · Benjamin M. Roberts🇦🇺
We devise and demonstrate a method to search for non-gravitational couplings of ultralight dark matter to standard model particles using space-time separated atomic clocks and cavity-stabilized lasers. By making use of space-time separated sensors, which probe different values of an oscillating dark matter field, we can search for couplings that cancel in typical local experiments. This provides sensitivity to both the temporal and spatial fluctuations of the field. We demonstrate this method using existing data from a frequency comparison of lasers stabilized to two optical cavities connected via a 2220 km fiber link [Schioppo et al., Nat. Commun. 13, 212 (2022)], and from the atomic clocks on board the Global Position System satellites. Our analysis results in constraints on the coupling of scalar dark matter to electrons, d_me, for masses between 1e-19 eV/c^2 and 2e-15 eV/c^2. These are the first constraints on d_me alone in this mass range.
Chen Chen🇨🇳 · Christian S. Fischer🇩🇪 · Craig D. Roberts🇨🇳
A symmetry-preserving continuum approach to the calculation of baryon properties in relativistic quantum field theory is used to predict all form factors associated with nucleon-to- axial and pseudoscalar transition currents, thereby unifying them with many additional properties of these and other baryons. The new parameter-free predictions can serve as credible benchmarks for use in analysing existing and anticipated data from worldwide efforts focused on elucidation of properties.
Natsumi Ikeno🇯🇵 · Wei-Hong Liang🇨🇳 · Eulogio Oset🇪🇸
We make a study of the , one of the five states observed by the LHCb collaboration, which is well reproduced as a molecular state from the and channels mostly. The state with decays to in -wave and we include this decay channel in our approach, as well as the effect of the width. With all these ingredients, we determine the fraction of the width that goes into , which could be a measure of the molecular component, but due to a relatively big binding, compared to its analogous state, we find only a small fraction of about 3%, which makes this measurement difficult with present statistics. As an alternative, we evaluate the scattering length and effective range of the and channels which together with the binding and width of the state, could give us an answer to the issue of the compositeness of this state when these magnitudes are determined experimentally, something feasible nowadays, for instance, measuring correlation functions.
Jorge Baeza-Ballesteros🇪🇸 · Andrea Donini🇪🇸 · Gabriel Molina-Terriza🇪🇸 · Francesc Monrabal🇪🇸 · Ander Simón🇪🇸
A novel experimental setup to measure deviations from the distance dependence of Newtonian gravity was proposed in arXiv:1609.05654. The underlying theoretical idea was to study the orbits of a microscopically-sized planetary system composed of a ``Satellite'', with mass g, and a ``Planet'', with mass g at an initial distance of hundreds of microns. The detection of precession of the orbit in this system would be an unambiguous indication of a central potential with terms that scale with the distance differently from . This is a huge advantage with respect to the measurement of the absolute strength of the attraction between two bodies, as most electrically-induced background potentials do indeed scale as . Detection of orbit precession is unaffected by these effects, allowing for better sensitivities. In arXiv:2106.08611, the impact of other subleading backgrounds that may induce orbit precession, such as, {\em e.g.}, the electrical Casimir force or general relativity, was studied in detail. It was found that the proposed setup could test Yukawa-like corrections, , to the potential with couplings as low as for distances as small as m, improving by roughly an order of magnitude present bounds. In this paper, we start to move from a theoretical study of the proposal to a more realistic implementation of the experimental setup. As a first step, we study the impact of air viscosity on the proposed setup and see how the setup should be modified in order to preserve the theoretical sensitivity achieved in our previous works.
Marco Drewes🇧🇪 · Sebastian Zell🇧🇪
Axion-like particles with a coupling to non-Abelian gauge fields at finite temperature can experience dissipation due to sphaleron heating. This could play an important role for warm inflation or dynamical dark energy. We investigate to what degree the efficiency of this non-perturbative mechanism depends on the details of the underlying particle physics model. For a wide range of scenarios and energy scales, we find that a previously discussed suppression of sphaleron heating by light fermions can be alleviated. As an outlook, we point out that fermionic effects may provide a new mechanism for ending warm inflation.
Kåre Fridell🇯🇵 · Chandan Hati🇪🇸 · Volodymyr Takhistov🇯🇵
Nucleon decays are generic predictions of motivated theories, including those based on the unification of forces and supersymmetry. We demonstrate that non-canonical nucleon decays offer a unique opportunity to broadly probe light new particles beyond the Standard Model with masses below few GeV over decades in mass range, including axion-like particles, dark photons, sterile neutrinos, and scalar dark matter. Conventional searches can misinterpret and even completely miss such new physics. We propose a general strategy based on momenta of visible decay final states to probe these processes, offering a rich physics program for existing and upcoming experiments such as Super-Kamiokande, Hyper-Kamiokande, DUNE, and JUNO.
Yu-Cheng Qiu🇨🇳 · Jie Sheng🇨🇳 · Liang Tan🇨🇳 · Chuan-Yang Xing🇨🇳
Atomic dark matter is usually considered to be produced asymmetrically in the early Universe. In this work, we first propose that the symmetric atomic dark matter can be thermally produced through the freeze-out mechanism. The dominant atom anti-atom annihilation channel is the atomic rearrangement. It has a geometrical cross section much larger than that of elementary fermions. After the atomic formation, this annihilation process further depletes dark matter particles and finally freezes out. To give the observed dark matter relic, the dark atoms are naturally ultraheavy, ranging from to .
Following previous work we further explore the possibility that the chirally broken phase of gauge theories admits an infrared fixed point interpretation. The slope of the function, , is found to vanish at the infrared fixed point which has several attractive features such as logarithmic running. We provide a more in-depth analysis of our previous result that the mass anomalous assumes at the fixed point. The results are found to be consistent with supersymmetric gauge theories. In a second part the specific properties of a dilaton, the (pseudo) Goldstone, due to spontaneous symmetry breaking are investigated. Dilaton soft theorems indicate that a soft dilaton mass can only originate from an operator of scaling dimension two. In the gauge theory this role is taken on by the -operator. The QCD dilaton candidate, the meson is investigated. Singlet-octet mixing is found to be important. We briefly discuss the dilaton as a candidate for the Higgs boson, which relies on the ratio of dilaton to pion decay constant being close to unity. In QCD this is approximately satisfied but it is remains unclear if this is accidental or whether there is unknown reason behind it.
Ya-Wen Pan🇨🇳 · Ming-Zhu Liu🇨🇳 · Jun-Xu Lu🇨🇳 · Li-Sheng Geng🇨🇳
Assuming that is a molecular state with a binding energy of 45 MeV, we investigate the existence of four-hadron molecules, and , with the Gaussian expansion method. Their binding energies are MeV and MeV below the mass thresholds of and . The state has a decay width of MeV due to the complex interaction. Further theoretical studies of and experimental searches for such four-hadron molecules can help deepen the understanding of the nonperturbative strong interaction in a nontrivial way.
Basabendu Barman🇮🇳 · Arghyajit Datta🇰🇷
Assuming axions are potential dark matter (DM) candidate that make up all of the DM abundance, we discuss production of axions via (i) standard misalignment mechanism during the period of reheating and (ii) graviton-mediated 2-to-2 scattering of the inflaton and bath particles, where the inflaton oscillates in a monomial potential with a general equation of state. Considering reheating takes place purely gravitationally, mediated by massless gravitons, we explore the viable region of the parameter space that agrees with the observed DM relic abundance, satisfying bounds from big bang nucleosynthesis (BBN) and cosmic microwave background radiation (CMB). We also discuss complementarity between dedicated axion search experiments and futuristic gravitational wave search facilities in probing the viable parameter space.
Marco Drewes🇧🇪 · Yannis Georis🇧🇪 · Juraj Klaric🇧🇪 · Philipp Klose🇨🇭
Hot viscous plasmas unavoidably emit a gravitational wave background, similar to electromagnetic black body radiation. We study the contribution from hidden particles to the diffuse background emitted by the primordial plasma in the early universe. While this contribution can easily dominate over that from Standard Model particles, we find that both are capped by a generic upper bound that makes them difficult to detect with interferometers in the foreseeable future. We illustrate our results for axions and heavy neutral leptons. Finally, our results suggest that previous works overestimated the gravitational wave background from particle decays out of thermal equilibrium.
The properties of the neutral pion in quark matter under the influence of an external magnetic field are studied. The effects of the anomalous magnetic moments (AMM) of the quarks at finite density is considered. The inclusion of the AMM into the NJL model gives rise to additional magnetic effects. In particular the Dirac sea produce new divergences in the vacuum contributions, which depend explicitly on the magnetic field. An improper treatment of these contributions is the source of unphysical results, as emphasized in recent investigations. The pion polarization function is evaluated in the random phase approximation using analytic regularization and a subtraction scheme to deal with such divergencies. This procedure is combined with the standard three momentum cutoff, and reduces to it for vanishing magnetic intensity. The pion mass and coupling constant are evaluated for a wide range of magnetic intensity and baryonic density.
G. Buchalla🇩🇪 · F. König🇩🇪 · Ch. Müller-Salditt🇩🇪 · F. Pandler🇩🇪
We use functional methods to match the Two-Higgs Doublet Model with heavy scalars in the nondecoupling regime to the appropriate nonlinear effective field theory, which takes the form of an electroweak chiral Lagrangian (HEFT). The effective Lagrangian is derived to leading order in the chiral counting. This includes the loop induced and local terms, which enter at the same chiral order as their counterparts in the Standard Model. An algorithm is presented that allows us to compute the coefficient functions to all orders in . Some of the all-orders results are given in closed form. The parameter regimes for decoupling, nondecoupling and alignment scenarios in the effective field theory context and some phenomenological implications are briefly discussed.
In this paper we argue that exclusive photoproduction of -meson pairs can be used as a complementary tool for studies of the generalized parton distributions of the target. We analyzed the photoproduction of the pseudoscalar-vector pairs with net zero electric charge (e.g. , , ) and found that it allows to study the chiral even GPDs in ERBL region. A unique feature of the suggested process is contribution of the gluon and just one of the light quark flavors. We made numerical estimates in the kinematics of the future Electron Ion Collider and found that numerically the production cross-section is reasonably large for experimental studies, thus justifying its viability as a complementary probe of GPDs.
Eduardo S. Fraga🇧🇷 · Letícia F. Palhares🇧🇷 · Tulio E. Restrepo🇧🇷
We compute the pressure from first principles within perturbative QCD at finite baryon density and very high magnetic fields up to two-loops and with physical quark masses. The region of validity for our framework is given by , where is the strange quark mass, is the quark chemical potential, is the fundamental electric charge, and is the magnetic field strength. We include the effects of the renormalization scale in the running coupling, , and running strange quark mass. We also discuss the simplifications that come about in the chiral limit. The effectively negligible contribution of the exchange diagram allows for building a simple analytic model for the equation of state for pure quark magnetars and computing their mass and radius at very large values of . These results provide constraints on the behavior of the maximum mass and associated radius from perturbative QCD. We also discuss the magnetic bag model for extreme magnetic fields.
Supersymmetric models with low electroweak fine-tuning are more prevalent on the string landscape than fine-tuned models. We assume a fertile patch of landscape vacua containing the minimal supersymmetric standard model (MSSM) as a low-energy EFT. Such models are characterized by light higgsinos in the mass range of a few hundred GeV whilst top squarks are in the 1-2.5 TeV range. Other sparticles are generally beyond current LHC reach. We evaluate prospects for top squark searches of the expected natural SUSY at HL-LHC.
We investigate the Two-Higgs-Doublet-Standard Model-Axion-Seesaw-Higgs-Portal inflation (2hdSMASH) model consisting of two Higgs doublets, a Standard Model (SM) singlet complex scalar and three SM singlet right-handed Majorana neutrinos that can address the strong CP problem, dark matter, neutrino masses, baryogenesis and inflation. We identify inflationary directions consistent with successful inflation and theoretical constraints including perturbative unitarity, boundedness-from-below conditions and high scale validity upto the PLANCK scale. Further, we present representative benchmark points satisfying theoretical and experimental constraints potentially accessible at future colliders.
Elisa Todarello🇮🇹 · Marco Regis🇮🇹 · Marco Taoso🇮🇹 · Maurizio Giannotti🇪🇸 · Jaime Ruz🇪🇸 · Julia K. Vogel🇪🇸
The exploration of the parameter space of axion and axion-like particle dark matter is a major aim of the future program of astroparticle physics investigations. In this context, we present a possible strategy that focuses on detecting radio emissions arising from the conversion of dark matter axions in the Sun's magnetic field, including conversion in sunspots. We demonstrate that near-future low-frequency radio telescopes, such as the SKA Low, may access regions of unexplored parameter space for masses eV.
Jayita Lahiri🇩🇪 · Subhaditya Bhattacharya🇮🇳 · Purusottam Ghosh🇮🇳 · Biswarup Mukhopadhyaya🇮🇳
We investigate ways of identifying two kinds of dark matter (DM) component particles at high-energy colliders. The strategy is to notice and distinguish double-peaks(humps) in the missing energy/transverse energy distribution. The relative advantage of looking for {\em missing energy} is pointed out, in view of the fact that the longitudinal component of the momentum imbalance becomes an added input. It thus turns out that an electron-positron collider is better suited for discovering a two-component DM scenario. Furthermore, using Gaussian fits of the distribution histograms, we develop a set of criteria to evaluate the distinguishability of the two-peaks quantitatively.
Riccardo Barbieri🇮🇹 · Gino Isidori🇨🇭
We construct two concrete examples of flavour non-universal gauge theories which, after the inclusion of all gauge invariant operators, allow to describe the observed pattern of flavour in the charged fermion sector without any small Yukawa coupling (). Guided by the criterium of minimality, we assume that flavour non universality is confined to the Abelian sector of the gauge group: the universal hypercharge emerges after a sequence of symmetry-breaking steps characterised by two high mass scales, , where the second and the first fermion generations get their mass respectively. At least in one of the two models the smaller of these scales can be in the 10 TeV range, consistently with current bounds from flavour observables. Both models are extended to include as well neutrino masses and mixings.
Yao Ma🇨🇭
The method of regions, which provides a systematic approach for computing Feynman integrals involving multiple kinematic scales, proposes that a Feynman integral can be approximated and even reproduced by summing over integrals expanded in certain regions. A modern perspective of the method of regions considers any given Feynman integral as a specific Newton polytope, defined as the convex hull of the points associated with Symanzik polynomials. The regions then correspond one-to-one with the lower facets of this polytope. As Symanzik polynomials correspond to the spanning trees and spanning 2-trees of the Feynman graph, a graph-theoretical study of these polynomials may allow us to identify the complete set of regions for a given expansion. In this work, our primary focus is on three specific expansions: the on-shell expansion of generic wide-angle scattering, the soft expansion of generic wide-angle scattering, and the mass expansion of heavy-to-light decay. For each of these expansions, we employ graph-theoretical approaches to derive the generic forms of the regions involved in the method of regions. The results, applicable to all orders, offer insights that can be leveraged to investigate various aspects of scattering amplitudes.
Joey Huston🇺🇸 · Klaus Rabbertz🇩🇪 · Giulia Zanderighi🇩🇪
This article is part of the "Review of Particle Physics" by the Particle Data Group and reviews the current status of quantum chromodynamics and the strong coupling constant . The latest updates as of August 2023 are included.
Volodymyr Gorkavenko🇺🇦 · Brij Jashal🇪🇸 · Valerii Kholoimov🇺🇦 · Yehor Kyselov🇺🇦 · Diego Mendoza🇪🇸 · Maksym Ovchynnikov🇩🇪 · Arantza Oyanguren🇪🇸 · Volodymyr Svintozelskyi🇺🇦 · Jiahui Zhuo🇪🇸
For years, it has been believed that the main LHC detectors can only restrictively play the role of a lifetime frontier experiment exploring the parameter space of long-lived particles (LLPs) - hypothetical particles with tiny couplings to the Standard Model. This paper demonstrates that the LHCb experiment may become a powerful lifetime frontier experiment if it uses the new Downstream algorithm reconstructing tracks that do not let hits in the LHCb vertex tracker. In particular, for many LLP scenarios, LHCb may be as sensitive as the proposed experiments beyond main LHC detectors for various LLP models, including heavy neutral leptons, dark scalars, dark photons, and axion-like particles.
Giorgio Arcadi🇮🇹 · Juan Carlos Criado🇪🇸 · Abdelhak Djouadi🇪🇸
We reanalyze the effective field theory (EFT) approach for the scenario in which the particles that account for the dark matter (DM) in the universe are vector states that interact only through the Standard Model-like Higgs boson. These DM particles are searched for in direct and indirect detection in astrophysical experiments and in invisible Higgs decays at the LHC. The constraints obtained in these two search types are complementary and correlated. In recent years, it has been advocated that the EFT approach is problematic for small DM mass and that it does not capture all the aspects of vector DM; one should thus rather interpret the searches in ultraviolet complete theories that are more realistic. In this note, we show that a more appropriate definition of the EFT with the introduction of an effective New Physics scale parameter, can encompass such issues. We illustrate this by matching the EFT to two examples of ultraviolet completions for it: the U(1) model with a dark photon and a model that was recently adopted by the LHC experiments in which vector-like fermions generate an effective interaction between the Higgs and the DM states at the one-loop level. Additionally, we find that the region of parameter space that is relevant for DM phenomenology is well inside the range of validity of the EFT. It thus provides a general parametrization of the effects of any ultraviolet model in the regime under exploration, making it the ideal framework for model-independent analyses of the vector DM Higgs-portal.
I. Plakias🇫🇷 · O. Sumensari🇫🇷
In this paper, we perform a comprehensive study of Lepton Flavor Violation (LFV) in semileptonic transitions in the framework of an Effective Field Theory with general flavor structure. We account for the Renormalization Group Equations (RGEs), which induce non-trivial correlations between the different types of LFV processes. In particular, we show that these loop effects are needed to improve the bounds on several coefficients that are not efficiently constrained at tree level. For illustration, we consider a few concrete scenarios, with predominant couplings to third-generation quarks, and we explore the correlations between the various tree- and loop-level constraints on these models. As a by-product, we also provide expressions for several semileptonic LFV meson decays by using the latest determinations of the relevant hadronic form factors on the lattice.
Angel Gómez Nicola🇪🇸 · Jacobo Ruiz de Elvira🇪🇸 · Andrea Vioque-Rodríguez🇪🇸
We review recent work regarding the role of light scalar resonances at finite temperature for chiral symmetry and restoration. The results obtained are based on unitarized Chiral Perturbation Theory and Ward Identities and are directly connected with presently open problems within the QCD phase diagram
Vladyslav Shtabovenko🇩🇪 · Rolf Mertig🇩🇪 · Frederik Orellana🇩🇰
In this work we report on a new version of FeynCalc, a Mathematica package widely used in the particle physics community for manipulating quantum field theoretical expressions and calculating Feynman diagrams. Highlights of the new version include greatly improved capabilities for doing multiloop calculations, including topology identification and minimization, optimized tensor reduction, rewriting of scalar products in terms of inverse denominators, detection of equivalent or scaleless loop integrals, derivation of Symanzik polynomials, Feynman parametric as well as graph representation for master integrals and initial support for handling differential equations and iterated integrals. In addition to that, the new release also features completely rewritten routines for color algebra simplifications, inclusion of symmetry relations between arguments of Passarino--Veltman functions, tools for determining matching coefficients and quantifying the agreement between numerical results, improved export to LaTeX and first steps towards a better support of calculations involving light-cone vectors.
K.S. Babu🇺🇸 · Rabindra N. Mohapatra🇺🇸 · Anil Thapa🇺🇸
We develop a grand unified theory of matter and forces based on the gauge symmetry with parity interchanging the two factor groups. Our main motivation for such a construction is to realize a minimal GUT embedding of left-right symmetric models that provide a parity solution to the strong CP problem without the axion. We show how the gauge couplings unify with an intermediate gauge symmetry , and establish its consistency with proton decay constraints. The model correctly reproduces the observed fermion masses and mixings and leads to naturally light Dirac neutrinos with their Yukawa couplings suppressed by a factor , the ratio of the intermediate scale to the GUT scale. We call this mechanism type II-Dirac seesaw. Furthermore, the model predicts and meV for the Dirac CP phase and the lightest neutrino mass. We demonstrate how the model solves the strong CP problem via parity symmetry.
A. Goudelis🇫🇷 · J. Kriewald🇸🇮 · E. Pinsard🇫🇷 · A. M. Teixeira🇫🇷
Extensions of the Standard Model featuring light vector bosons have been explored with the goal of resolving certain tensions between theory and experiment, among them the discrepancy in the anomalous magnetic moment of the muon, . In particular, this is the case of a minimal construction including a leptophilic, strictly flavour violating, vector boson . These new vector bosons are also well-motivated dark matter portals, with non-trivial couplings to stable, weakly interacting states which can account for the correct dark matter density. Here we study the prospects of a Standard Model extension (via a vector boson and a fermionic dark matter candidate) concerning signatures at the LHC, and at future lepton and hadron colliders.We discuss the cross-sections of several processes leading to same- and opposite-sign muon-tau lepton pairs in the final state, as well as final states with missing energy (in the form of neutrinos and/or dark matter). Our findings suggest that a future muon collider offers the best prospects to probe this model (together with searches for dilepton pairs and missing energy signatures at the FCC-ee running at the -pole); moreover, the complementarity of the different future high-energy colliders is also paramount to probing distinct mass regimes.
Ricardo Z. Ferreira🇵🇹 · Silvia Gasparotto🇪🇸 · Takashi Hiramatsu🇯🇵 · Ippei Obata🇯🇵 · Oriol Pujolas🇪🇸
The evidence for a non-vanishing isotropic cosmic birefringence in recent analyses of the CMB data provides a tantalizing hint for new physics. Domain wall (DW) networks have recently been shown to generate an isotropic birefringence signal in the ballpark of the measured value when coupled to photons. In this work, we explore the axionic defects hypothesis in more detail and extending previous results to annihilating and late-forming networks, and by pointing out other smoking-gun signatures of the network in the CMB spectrum such as the anisotropic birefringent spectrum and B-modes. We also argue that the presence of cosmic strings in the network does not hinder a large isotropic birefringence signal because of an intrinsic environmental contribution coming from low redshifts thus leaving open the possibility that axionic defects can explain the signal. Regarding the remaining CMB signatures, with the help of dedicated 3D numerical simulations of DW networks, that we took as a proxy for the axionic defects, we show how the anisotropic birefringence spectrum combined with a tomographic approach can be used to infer the formation and annihilation time of the network. From the numerical simulations, we also computed the spectrum of gravitational waves (GWs) generated by the network in the post-recombination epoch and use previous searches for stochastic GW backgrounds in the CMB to derive for the first time a bound on the tension and abundance of networks with DWs that annihilate after recombination. Our bounds extend to the case where the network survives until the present time and improve over previous bounds by roughly one order of magnitude. Finally, we show the interesting prospects for detecting B-modes of DW origin with future CMB experiments.
Asmaa Abada🇫🇷 · Nicolás Bernal🇦🇪 · Antonio E. Cárcamo Hernández🇨🇱 · Sergey Kovalenko🇨🇱 · Téssio B. de Melo🇨🇱
We propose a class of models providing an explanation of the origin of light neutrino masses, the baryon asymmetry of the Universe via leptogenesis and offering viable dark matter candidates. In these models the Majorana masses of the active neutrino are generated by the inverse seesaw mechanism with the lepton number violating right-handed Majorana neutrino masses arising at three loops. The latter is ensured by the preserved discrete symmetries, which also guarantee the stability of the dark matter candidate. We focus on one of these models and perform a detailed analysis of the phenomenology of its leptonic sector. The model can successfully accommodate baryogenesis through leptogenesis in both weak and strong washout regimes. The lightest heavy fermion turns out to be a viable dark matter candidate, provided that the entries of the Majorana submatrix are in the keV to MeV range. The solutions are consistent with the experimental constraints, accommodating both mass orderings for active neutrinos, in particular charged-lepton flavor violating decays , , and the electron-muon conversion processes get sizable rates within future sensitivity reach.
Ting Cheng🇩🇪 · Hao-Jui Kuan🇩🇪 · Ying-Ying Li🇨🇳 · Vedran Brdar🇺🇸
The IceCube collaboration pioneered the detection of neutrino events and the identification of astrophysical sources of high-energy neutrinos. In this study, we explore scenarios in which high-energy neutrinos are produced in the vicinity of astrophysical objects with strong magnetic field, such as magnetars. While propagating through such magnetic field, neutrinos experience spin precession induced by their magnetic moments, and this impacts their helicity and flavor composition at Earth. Considering both flavor composition of high-energy neutrinos and Glashow resonance events we find that detectable signatures may arise at neutrino telescopes, such as IceCube, for presently unconstrained neutrino magnetic moments in the range between and .
Alessio Giarnetti🇮🇹 · Juan Herrero-Garcia🇪🇸 · Simone Marciano🇮🇹 · Davide Meloni🇮🇹 · Drona Vatsyayan🇪🇸
With just the Standard Model Higgs doublet, there are only three types of seesaw models that generate light Majorana neutrino masses at tree level after electroweak spontaneous symmetry breaking. However, if there exist additional TeV scalars acquiring vacuum expectation values, coupled with heavier fermionic multiplets, several new seesaw models become possible. These new seesaws are the primary focus of this study and correspond to the tree-level ultraviolet completions of the effective operators studied in a companion publication. We are interested in the genuine cases, in which the standard seesaw contributions are absent. In addition to the tree-level generation of neutrino masses, we also consider the one-loop contributions. Furthermore, we construct low-energy versions that exhibit a very rich phenomenology. Specifically, we scrutinise the generation of dimension-6 operators and explore their implications, including non-unitarity of the leptonic mixing matrix, non-universal boson interactions, and lepton flavor violation. Finally, we provide (Generalised) Scotogenic-like variants that incorporate viable dark matter candidates.
Piotr Bargiela🇨🇭 · Fabrizio Caola🇬🇧 · Herschel Chawdhry🇺🇸 · Xiao Liu🇬🇧
We present a calculation of the bosonic contribution to the two-loop mixed QCD-electroweak scattering amplitudes for -boson production in association with one hard jet at hadron colliders. We employ a method to calculate amplitudes in the 't Hooft-Veltman scheme that reduces the amount of spurious non-physical information needed at intermediate stages of the computation, to keep the complexity of the calculation under control. We compute all the relevant Feynman integrals numerically using the Auxiliary Mass Flow method. We evaluate the two-loop scattering amplitudes on a two-dimensional grid in the rapidity and transverse momentum of the boson, which has been designed to yield a reliable numerical sampling of the boosted- region. This result provides an important building block for improving the theoretical modelling of a key background for monojet searches at the LHC.
Thorsten Feldmann🇩🇪 · Nico Gubernari🇩🇪
We investigate for the first time a certain class of non-factorisable contributions of the four-quark operators in the weak effective Hamiltonian to the decay amplitude. We focus on the case where a virtual photon is radiated from one of the light constituents of the baryon, in the kinematic situation of large hadronic recoil with an energetic baryon in the final state. The effect on the suitably defined ``non-local form factors'' is calculated using the light-cone sum rule approach for a correlator with an interpolating current for the light baryon. We find that this approach requires the introduction of new soft functions that generalise the standard light-cone distribution amplitudes (LCDAs) for the heavy baryon. We give a heuristic discussion of their properties and a model that relates them to the standard LCDAs. Within this framework, we provide numerical results for the size of the non-local form factors considered.
Prudhvi N. Bhattiprolu🇺🇸 · Robert McGehee🇺🇸 · Aaron Pierce🇺🇸
We describe a simple dark sector structure which, if present, has implications for the direct detection of dark matter (DM): the Dark Sink. A Dark Sink transports energy density from the DM into light dark-sector states that do not appreciably contribute to the DM density. As an example, we consider a light, neutral fermion which interacts solely with DM via the exchange of a heavy scalar . We illustrate the impact of a Dark Sink by adding one to a DM freeze-in model in which couples to a light dark photon which kinetically mixes with the Standard Model (SM) photon. This freeze-in model (absent the sink) is itself a benchmark for ongoing experiments. In some cases, the literature for this benchmark has contained errors; we correct the predictions and provide them as a public code. We then analyze how the Dark Sink modifies this benchmark, solving coupled Boltzmann equations for the dark-sector energy density and DM yield. We check the contribution of the Dark Sink 's to dark radiation; consistency with existing data limits the maximum attainable cross section. For DM with a mass between , adding the Dark Sink can increase predictions for the direct detection cross section all the way up to the current limits.
Ephraim Gau🇺🇸 · Fazlollah Hajkarim🇺🇸 · Steven P. Harris🇺🇸 · P. S. Bhupal Dev🇺🇸 · Jean-Francois Fortin🇨🇦 · Henric Krawczynski🇺🇸 · Kuver Sinha🇺🇸
We derive new constraints on axion-like particles (ALPs) using precision -ray polarization studies of magnetars. Specifically, we use the first detection of polarized -rays from the magnetars 4U 0142+61 and 1RXS J170849.0-400910 by the Imaging -ray Polarimetry Explorer (IXPE) to place bounds on the product of the ALP-photon and ALP-nucleon couplings, , with being responsible for ALP production in the core of the magnetar and controlling the ALP-photon conversion probability in the magnetosphere. These bounds are most sensitive to the magnetar core temperature, and we use two benchmark values of K and K to derive our constraints. For the latter choice, our bounds are competitive with the existing bounds on the coupling product coming from a combination of CAST (for ) and SN1987A (for ). We advocate for more precise and extensive observational campaigns in the higher end of the keV spectral window, where ALP-induced polarization is the strongest. We further advocate for hard -ray polarization studies of young, hot, near-Earth magnetars with strong magnetic fields.
N. Furey🇩🇪
In this article, we bypass the detailed symmetry breaking pathways established in [1]. Instead, a direct route from the Spin(10) model to the Standard Model is enabled via a single algebraic constraint. This single constraint, however, may be reconfigured as a requirement that three actions coincide on a fixed space of multi-vector fermions. This breaking (from a three-way intersection) mirrors, in certain ways, the breaking (from a three-way intersection) in the context of octonionic triality. By extending this result to include quaternions and complex numbers, we find that a five-way intersection breaks . These are the Standard Model's unbroken gauge symmetries, post-Higgs-mechanism.
We suggest a new explanation of flatness of galaxies rotation curves without invoking dark matter. For this purpose a new gravitational tensor field is introduced in addition to the metric tensor.
Nobuhiro Maekawa🇯🇵 · Taiju Tanii🇯🇵
The natural grand unified theories solve various problems of the supersymmetric grand unified theory and give realistic quark and lepton mass matrices under the natural assumption that all terms allowed by the symmetry are introduced with O(1) coefficients. However, because of the natural assumption, it is difficult to achieve the gauge coupling unification without tuning, while keeping neutrino masses at realistic values. In this paper, we try to avoid this tension between the neutrino masses and the gauge coupling unification, by introducing suppression factors for several terms. These suppression factors can be understood by approximate symmetries in some of the solutions. We show that one of the most important results in the natural GUT scenario, that the nucleon decay mediated by superheavy gauge fields is enhanced due to smaller unification scale while the nucleon decay mediated by superheavy colored Higgs is suppressed, can change in those models proposed in this paper.
Ren-Hua Wua🇨🇳 · Chen-Yu Wang🇨🇳 · Ce Meng🇨🇳 · Yan-Qing Ma🇨🇳 · Kuang-Ta Chao🇨🇳
We study the mass spectra of hidden-charm tetraquark systems with quantum numbers using QCD sum rules. The analysis incorporates the complete next-to-leading order (NLO) contribution to the perturbative QCD part of the operator product expansions, with particular attention to operator mixing effects due to renormalization group evolution. For the system, the masses of two mixed operators, and , are determined to be GeV and GeV, respectively, closely matching those of (3900) and . Similarly, for the states, the masses of and are found to be GeV and GeV, respectively, in close proximity to (3983)/(4000) and (4220), consistent with the expectation that they are the partners of (3900) and (4020). Our results highlight the crucial role of operator mixing, an inevitable effect in a complete NLO calculation, in achieving a robust phenomenological description for the tetraquark system.
Yang Bai🇺🇸 · Sida Lu🇨🇳 · Nicholas Orlofsky🇵🇱
The detection of gravitational waves (GWs) has led to a deeper understanding of binaries of ordinary astrophysical objects, including neutron stars and black holes. In this work, we point out that binary systems may also exist in a dark sector with astrophysical-mass macroscopic dark matter. These "dark binaries," when coupled to an additional attractive long-range dark force, may generate a stochastic gravitational wave background (SGWB) with a characteristic spectrum different from ordinary binaries. We find that the SGWB from planet-mass dark binaries is detectable by space- and ground-based GW observatories. The contribution to the SGWB today is smaller from binaries that merge before recombination than after, avoiding constraints on extra radiation degrees of freedom while potentially leaving a detectable GW signal at high frequencies up to tens of GHz.
C. Condeescu🇷🇴 · D. M. Ghilencea🇷🇴 · A. Micu🇷🇴
We review (non-supersymmetric) gauge theories of four-dimensional space-time symmetries and their quadratic action. The only true gauge theory of such a symmetry (with a physical gauge boson) that has an exact geometric interpretation, generates Einstein gravity in its spontaneously broken phase and is anomaly-free, is that of Weyl gauge symmetry (of dilatations). Gauging the full conformal group does not generate a true gauge theory of physical (dynamical) associated gauge bosons. Regarding the Weyl gauge symmetry, it is naturally realised in Weyl conformal geometry, where it admits two different but equivalent geometric formulations, of same quadratic action: one non-metric but torsion-free, the other Weyl gauge-covariant and metric (with respect to a new differential operator). To clarify the origin of this intriguing result, a third equivalent formulation of this gauge symmetry is constructed using the standard, modern approach on the tangent space (uplifted to space-time by the vielbein), which is metric but has vectorial torsion. This shows an interesting duality vectorial non-metricity vs vectorial torsion of the corresponding formulations, related by a projective transformation. We comment on the physical meaning of these results.
Xiaojun Yao🇺🇸 · Lukas Ebner🇩🇪 · Berndt Müller🇺🇸 · Andreas Schäfer🇩🇪 · Clemens Seidl🇩🇪
We report on progress in full quantum understanding of thermalization in non-Abelian gauge theories. Specifically, we test the eigenstate thermalization hypothesis for (2+1)-dimensional SU(2) lattice gauge theory.
Djuna Croon🇬🇧 · Jeremy Sakstein🇺🇸
Using high-resolution simulations of black hole formation from the direct collapse of massive stars undergoing pulsational pair-instability supernovae (PPISN), we find a new phenomenon which significantly affects the explosion and leads to two peaks in the resulting black hole mass function (BHMF). Lighter stars experiencing the pair-instability can form a narrow shell in which alpha ladder reactions take place, exacerbating the effect of the PPISN. The shell temperature in higher mass stars ( at the onset of helium burning for population-III stars with metallicity ) is too low for this to occur. As a result, the spectrum of black holes exhibits a shoulder feature whereby a large range of initial masses result in near-identical black hole masses. PPISN therefore predict two peaks in the mass function of astrophysical black holes -- one corresponding to the location of the upper black hole mass gap and a second corresponding to the location of the shoulder. This shoulder effect may explain the peak at in the LIGO/Virgo/KAGRA GWTC-3 catalog of merging binary black holes.
Katsuki Aoki🇯🇵 · Yu-tin Huang🇹🇼
In this work, we study the analytic properties of S-matrix for unstable particles, which is defined as the residues on the unphysical sheets where unstable poles reside. We demonstrate that anomalous thresholds associated with UV physics are unavoidable for unstable particles. This is in contrast to stable particles, where the anomalous thresholds are due to IR physics, set by the scale of the external kinematics. As a result, any dispersive representation for the amplitude will involve contributions from these thresholds that are not computable from the IR theory, and thus invalidate the general positivity bound. Indeed using toy models, we explicitly demonstrate that the four-derivative couplings for unstable particles can become negative, violating positivity bounds even for non-gravitational theories. Along the way, we show that contributions from anomalous thresholds in a given channel can be captured by the double discontinuity of that channel.
We propose that the merger rate of primordial black hole (PBH) binaries can be a probe of Hubble parameter by constraining PBH mass function in the redshifted mass distribution of PBH binaries. In next-generation gravitational wave (GW) detectors, the GWs from PBH binaries would be detected at high redshifts, which gives their redshifted mass and luminosity distances. From a number of detected events, the redshifted mass distribution of PBH binaries can be statistically obtained, and it depends on PBH mass function and redshift distribution of detected PBH binaries. The PBH mass function can be inversely solved by applying the gradient descent method in the relation between redshifted mass distribution and redshift distribution. However, the construction of redshift distribution requires an assumed Hubble parameter in a background cosmology to extract redshift from luminosity distances, which causes solved PBH mass function also depends on assumed Hubble parameter. To determine the Hubble parameter, the merger rate of PBH binaries constrains on this Hubble parameter-dependent PBH mass function by comparing calculated merger rate distribution with observed one, and the best-fit result produces an approximate mass distribution of the physical PBH mass function and pins down the Hubble parameter.
Riccardo Ciccone🇮🇹 · Lorenzo Di Pietro🇮🇹 · Marco Serone🇮🇹
We study the chiral Gross-Neveu model at finite temperature and chemical potential . The analysis is performed by relating the theory to a Wess-Zumino-Witten model with appropriate levels and global identifications necessary to keep track of the fermion spin structures. At we show that a certain -valued 't Hooft anomaly forbids the system to be trivially gapped when fermions are periodic along the thermal circle for any and any . We also study the two-point function of a certain composite fermion operator which allows us to determine the remnants for of the inhomogeneous chiral phase configuration found at for any and any . The inhomogeneous configuration decays exponentially at large distances for anti-periodic fermions while it persists for and any for periodic fermions, as expected from anomaly considerations. A large analysis confirms the above findings.
Petr Beneš🇨🇿 · Filip Blaschke🇨🇿
We discuss a class of effective extensions of the Georgi-Glashow model and discuss its Bogomol'nyi-Prasad-Sommerfield (BPS) limit. We identify a specific subclass of these models that admit analytical solutions of the monopole type. We present some concrete examples and find that the resulting monopoles tend to have their energy concentrated not in their center, but rather in a spherical shell around it.
Wojciech Florkowski🇵🇱 · Radoslaw Ryblewski🇵🇱 · Piotr Salabura🇵🇱 · Nikodem Witkowski🇵🇱
A recently formulated thermal model for hadron production in heavy-ion collisions in the few-GeV energy regime is combined with the idea that some part of protons and neutrons present in the original thermal system forms deuterons via the coalescence mechanism. Using realistic parametrizations of the freeze-out conditions, which reproduce well the spectra of protons and pions, we make predictions for deuteron transverse-momentum and rapidity spectra. The best agreement with the experimentally known deuteron yield is obtained if the freeze-out temperature is relatively high and, accordingly, the system size at freeze-out is rather small. In addition, the standard Gaussian distribution of the relative distance between nucleons is replaced by the distribution resulting from their independent and approximately uniform production inside the initial thermal system.
Hermann Krebs🇩🇪 · Evgeny Epelbaum🇩🇪
Low-energy nuclear structure and reactions can be described in a systematically improvable way using the framework of chiral effective field theory. This requires solving the quantum mechanical many-body problem with regularized nuclear forces and current operators, derived from the most general effective chiral Lagrangian. To maintain the chiral and gauge symmetries, a symmetry preserving cutoff regularization has to be employed when deriving nuclear potentials. Here, we discuss various regularization techniques and show how this task can be accomplished by regularizing the pion field in the effective chiral Lagrangian using the gradient flow method. The actual derivation of the nuclear forces and currents from the regularized effective Lagrangian can be carried out utilizing the novel path-integral approach introduced in our earlier paper.
Cosmin Ilie🇺🇸 · Caleb Levy🇺🇸 · Jared Diks🇺🇸
In this work we demonstrate that Dark Matter (DM) evaporation severely hinders the effectiveness of exoplanets and Brown Dwarfs as sub-GeV DM probes. Moreover, we find useful analytic closed form approximations for DM capture rates for arbitrary astrophysical objects, valid in four disticnt regions in the parameter space. As expected, in one of those regions the Dark Matter capture saturates to its geometric limit, i.e. the entire flux crossing an object. As a consequence of this region, which for many objects falls within the parameter space not excluded by direct detection experiments, we point out the existence of a DM parameter dependent critical temperature (), above which astrophysical objects lose any sensitivity as Dark Matter probes. For instance, Jupiters at the Galactic Center have a ranging from K (for a Jupiter) to K (for ). This limitation is rarely (if ever) considered in the previous literature of indirect Dark Matter detection based on observable signatures of captured Dark Matter inside celestial bodies.
Victor V. Braguta🇷🇺 · Maxim N. Chernodub🇫🇷 · Artem A. Roenko🇷🇺
Using first-principle numerical simulations, we find a new spatially inhomogeneous phase in rigidly rotating gluon plasma. This mixed phase simultaneously possesses both confining and deconfining phases in thermal equilibrium. Unexpectedly, the local critical temperature of the phase transition at the rotation axis does not depend on the angular frequency within a few percent accuracy. Even more surprisingly, an analytic continuation of our results to the domain of real angular frequencies indicates a profound breaking of the Tolman-Ehrenfest law in the vicinity of the phase transition, with the confining (deconfining) phase appearing far (near) the rotation axis.
Sebastian Bieringer🇩🇪 · Gregor Kasieczka🇩🇪 · Maximilian F. Steffen · Mathias Trabs🇩🇪
Uncertainty estimation is a key issue when considering the application of deep neural network methods in science and engineering. In this work, we introduce a novel algorithm that quantifies epistemic uncertainty via Monte Carlo sampling from a tempered posterior distribution. It combines the well established Metropolis Adjusted Langevin Algorithm (MALA) with momentum-based optimization using Adam and leverages a prolate proposal distribution, to efficiently draw from the posterior. We prove that the constructed chain admits the Gibbs posterior as invariant distribution and approximates this posterior in total variation distance. Furthermore, we demonstrate the efficiency of the resulting algorithm and the merit of the proposed changes on a state-of-the-art classifier from high-energy particle physics.
Li Hu🇨🇳 · Rong-Gen Cai🇨🇳 · Shao-Jiang Wang🇨🇳
Recent detections of a low-frequency gravitational wave background (GWB) from various pulsar-timing-array (PTA) observations have renewed the interest in the inspiraling supermassive black hole binaries (SMBHBs), whose population is believed to be the most promising candidate with possible generalizations from including either orbital eccentricity or dark matter (DM) spike. In this paper, we show that the inclusion of both can further display distinctive features detectable in future PTA observations. With a typical initial eccentricity for the inspiraling SMBHBs, even a shallow DM spike can easily drive the orbital eccentricity close to , leaving behind a large turnover eccentricity when GWs begin to dominate the orbital circularization. In particular, the DM spike index universally manifests itself in the characteristic strain by in the far infrared and features a novel oscillation structure at low frequencies. Future PTA detection of such characteristics would be the smoking gun for the DM spike and even reveal the nature of DM.
Travis Dore🇩🇪 · Xiaojian Du🇪🇸 · Sören Schlichting🇩🇪
We use QCD effective kinetic theory to calculate far-from-equilibrium dynamics on an event-by-event basis within the Kø{}MPø{}ST framework. We present non-equilibrium charge response functions and the dynamical evolution of the conserved charge current pertinent to the early-time dynamics of heavy-ion collisions at the highest energies. The Kø{}MPø{}ST framework with conserved baryon, strangeness, and electric charges can then be readily implemented into a multistage model allowing for the initialization of a non-equilibrium charge current in hydrodynamic simulations.
Valerio De Luca🇺🇸 · Nicola Bellomo🇺🇸
Throughout the cosmic history, primordial black holes may experience an efficient phase of baryonic mass accretion from the surrounding medium. While the realm of accretion physics is marked by numerous uncertainties, and a comprehensive understanding remains elusive, recent investigations have delved into this area, exploring its implications for the cosmological evolution of these compact objects. Notably, primordial black holes could experience characteristic growths of their masses and spins, accompanied by the emission of radiation, ultimately responsible for feedback effects that could weaken the efficiency of the process. In this chapter we review the basic formalism to describe the accretion rate, luminosity function and feedback effects, in order to provide distinctive predictions for the evolution of the primordial black hole mass and spin parameters.
Oleg Komoltsev🇳🇴 · Rahul Somasundaram🇺🇸 · Tyler Gorda🇩🇪 · Aleksi Kurkela🇳🇴 · Jérôme Margueron🇫🇷 · Ingo Tews🇺🇸
We explore the consequences of imposing robust thermodynamic constraints arising from perturbative Quantum Chromodynamics (QCD) when inferring the dense-matter equation-of-state (EOS). We find that the termination density, up to which the EOS modeling is performed in an inference setup, strongly affects the constraining power of the QCD input. This sensitivity in the constraining power arises from EOSs that have a specific form, with drastic softening immediately above the termination density followed by a strong stiffening. We also perform explicit modeling of the EOS down from perturbative-QCD densities to construct a new QCD likelihood function that incorporates additional perturbative-QCD calculations of the sound speed and is insensitive to the termination density, which we make publicly available.
* 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.