Wed·Aug 30, 2023Wednesday·August 30, 2023

1. 01*

   The Flavor Puzzle: Textures and Symmetries

   Hans Peter Nilles🇩🇪 · Saul Ramos-Sanchez🇲🇽

   We discuss aspects of a promising top-down origin of flavor symmetries in particle physics. Modular transformations originating from string theory dualities are shown to play a crucial role. We introduce the notion of an "eclectic" flavor scheme that unifies traditional flavor symmetries, modular symmetries and CP-transformations. It exhibits the phenomenon of "Local Flavor Unification" with enhanced flavor symmetries at fixed points or lines in moduli space. Successful fits of masses and mixing angles of quarks and leptons are found in the vicinity of these points and lines.

   hep-phInt.J.Mod.Phys.A(2024)·9 citations
2. 02*

   The problem of flavour

   Gauhar Abbas🇮🇳 · Rathin Adhikari🇮🇳 · Eung Jin Chun🇰🇷 · Neelam Singh🇮🇳

   We review the problem of flavour tracing back to the days when the standard model was just coming together. We focus on the recently discussed new solutions of this problem, namely the Froggatt and Nielsen mechanism based on a novel discrete ${\mathcal{Z}}_{\mathrm{N}}\times {\mathcal{Z}}_{\mathrm{M}}$ flavour symmetry, and the standard hierarchical VEVs model. The standard HVM, and the Froggatt and Nielsen mechanism based on the ${\mathcal{Z}}_{\mathrm{N}}\times {\mathcal{Z}}_{\mathrm{M}}$ flavour symmetry, can be recovered from a new dark-technicolour paradigm, where the hierarchical VEVs or the flavon VEV may appear as the chiral multifermion condensates. In particular, there appears a novel feature that the solution of the flavour problem based on the discrete flavour symmetry can provide the so-called flavonic dark matter. This predicts a specific relation between the mass and the symmetry-breaking scale, which can be contrasted with the standard QCD axion. Moreover, a possible direction towards the Grand Unified framework is also discussed.

   hep-phhep-exEur.Phys.J.Plus(2025)·10 citations
3. 03*

   Matter-antimatter origin of cosmic magnetism

   Andrew Steinmetz🇺🇸 · Cheng Tao Yang🇺🇸 · Johann Rafelski🇺🇸

   We explore the hypothesis that the abundant presence of relativistic antimatter (positrons) in the primordial universe is the source of the intergalactic magnetic fields we observe in the universe today. We evaluate both Landau diamagnetic and magnetic dipole moment paramagnetic properties of the very dense primordial electron-positron $e^{+}{e}^{-}$-plasma, and obtain in quantitative terms the relatively small magnitude of the $e^{+}{e}^{-}$ magnetic moment polarization asymmetry required to produce a consistent self-magnetization in the universe.

   hep-phastro-ph.COPRD(2023)·10 citations
4. 04*

   Transverse dynamics of charmed hadrons in ultra-relativistic nuclear collisions

   Anton Andronic🇩🇪 · Peter Braun-Munzinger🇩🇪 · Hjalmar Brunßen🇩🇪 · Jana Crkovská🇩🇪 · Johanna Stachel🇩🇪 · Vytautas Vislavicius🇸🇪 · Martin Völkl🇩🇪

   Transverse momentum $p_{\mathrm{T}}$ spectra and anisotropic flow distributions are studied for charmonia and charmed hadrons produced in Pb-Pb collisions and measured with the ALICE detector at the CERN Large Hadron Collider (LHC). The investigations are performed within the framework of the Statistical Hadronization Model with the transverse dynamics evaluated using predictions from relativistic viscous hydrodynamics as implemented in the computer codes MUSIC and FluiduM. With this essentially parameter-free approach, mostly good agreement is obtained for $p_{\mathrm{T}}$ spectra in the range $p_{\mathrm{T}}$ $<10$ GeV/c. The calculations suggest a hardening of the $\mathrm{J}/\psi$ $p_{\mathrm{T}}$ distribution for more central collisions while the data show the opposite trend. The observed wide distribution in $p_{\mathrm{T}}$ of anisotropic flow coefficients v${}_2$ and v${}_3$ for charmonia is also well reproduced, while their magnitude is generally somewhat over predicted. This finding may be connected to a difference in spatial distribution between light and charmed hadrons due to a different diffusion of light and heavy quarks in the hot fireball.

   hep-phJHEP(2024)·11 citations
5. 05*

   Spacetime dynamics of chiral magnetic currents in a hot non-Abelian plasma

   Sebastian Grieninger🇺🇸 · Dmitri E. Kharzeev🇺🇸

   The correlations of electric currents in hot non-Abelian plasma are responsible for the experimental manifestations of the chiral magnetic effect (CME) in heavy-ion collisions. We evaluate these correlations using holography, and show that they are driven by large-scale topological fluctuations. In a non-Abelian plasma with chiral fermions, local axial charge can be generated either by topological fluctuations (creating domains with nonzero Chern-Simons number) or by thermal fluctuations. Within holography, we investigate the dynamical creation of the axial charge and isolate the imprint of the topological dynamics on the spatial correlations of electric current. In particular, we show that the spatial extent of the current correlation is quite large ($\sim 1\mathrm{fm}$) and grows with time, which is consistent with sphaleronlike dynamics. We provide numerical estimates for this spatial size that can be used as an input in phenomenological analyses.

   hep-phhep-thnucl-thPRD(2023)·8 citations
6. 06*

   Real-time dynamics of axial charge and chiral magnetic current in a non-Abelian expanding plasma

   Sebastian Grieninger🇺🇸 · Sergio Morales-Tejera🇪🇸

   Understanding axial charge dynamics driven by changes in Chern-Simons number densities is a key aspect in understanding the chiral magnetic effect (CME) in heavy-ion collisions. Most phenomenological simulations assume that a large amount of axial charge is produced in the initial stages and that axial charge is conserved throughout the simulation. Within an (expanding) homogeneous holographic plasma, we investigate the real-time axial charge relaxation dynamics and their impact on the chiral magnetic current. Moreover, we discuss the real-time interplay of the non-Abelian and the Abelian chiral anomaly in the presence of a strong magnetic field. In the expanding plasma, the Chern-Simons diffusion rate and thus the axial charge relaxation rate are time dependent due to the decaying magnetic field. We quantify the changes in the late time falloffs and establish a horizon formula for the chiral magnetic current.

   hep-phhep-thnucl-thPRD(2023)·10 citations
7. 07*

   First simultaneous global QCD analysis of dihadron fragmentation functions and transversity parton distribution functions

   C. Cocuzza🇺🇸 · A. Metz🇺🇸 · D. Pitonyak🇺🇸 · A. Prokudin🇺🇸 · N. Sato🇺🇸 · R. Seidl🇺🇸

   We perform a comprehensive study within quantum chromodynamics (QCD) of dihadron observables in electron-positron annihilation, semi-inclusive deep-inelastic scattering, and proton-proton collisions, including recent cross section data from Belle and azimuthal asymmetries from STAR. We extract simultaneously for the first time ${\pi }^{+}{\pi }^{-}$ dihadron fragmentation functions (DiFFs) and the nucleon transversity distributions for up and down quarks as well as antiquarks. For the transversity distributions we impose their small-$x$ asymptotic behavior and the Soffer bound. In addition, we utilize a new definition of DiFFs that has a number density interpretation to then calculate expectation values for the dihadron invariant mass and momentum fraction. Furthermore, we investigate the compatibility of our transversity results with those from single-hadron fragmentation (from a transverse momentum dependent/collinear twist-3 framework) and the nucleon tensor charges computed in lattice QCD. We find a universal nature to all of this available information. Future measurements of dihadron production can significantly further this research, especially, as we show, those that are sensitive to the region of large parton momentum fractions.

   hep-phhep-exhep-latnucl-ex+1PRD(2024)·60 citations
8. 08*

   Sieving parton distribution function moments via the moment problem

   Xiaobin Wang🇨🇳 · Minghui Ding🇩🇪 · Lei Chang🇨🇳

   We apply a classical mathematical problem, the moment problem, with its related mathematical achievements, to the study of the parton distribution function (PDF) in hadron physics, and propose a strategy to sieve the moments of the PDF by exploiting its properties such as continuity, unimodality, and symmetry. Through an error-inclusive sifting process, we refine three sets of PDF moments from Lattice QCD. This refinement significantly reduces the errors, particularly for higher order moments, and locates the peak of PDF simultaneously. As our strategy is universally applicable to PDF moments from any method, we strongly advocate its integration into all PDF moment calculations.

   hep-phhep-latPLB(2024)·4 citations
9. 09*

   Note on the electromagnetic radius of proton

   M. Ridwan🇮🇩 · T. Mart🇮🇩

   We have analyzed the proton form factor data by using a number of phenomenological parameterizations (models) and extracting the proton electric and magnetic radii. To this end we performed a global fit to all available form factor data, with the virtual photon momentum squared $Q^2$ from $0.0002$ to nearly 10 GeV${}^2$ for electric form factor and from $0.015$ to 31 GeV${}^2$ for magnetic one. Special attention was given to the small structure shown by the form factor data near $Q^2=0.2$ GeV${}^2$. It was found that different models yield different structures with different numbers of minimum at this kinematics. Since the slope of form factor in the limit of $Q^2\to 0$ is influenced by this structure, the extracted proton radii are consequently different for different models. Our finding recommends that future experiments should focus on this kinematics instead of low $Q^2$. Experimental data with accuracies comparable to those of the latest data at low $Q^2$ would clearly help to clarify the effect of this structure on the proton charge radius. Interestingly, most of the extracted proton charge radii were found to be closer to the value obtained from the muonic hydrogen atom spectroscopy.

   hep-phnucl-exnucl-thphysics.pop-phMod.Phys.Lett.A(2023)·4 citations
10. 10*

    The electromagnetic form factors in the $N_f=4$ holographic QCD

    Hiwa A. Ahmed🇨🇳 · Yidian Chen🇨🇳 · Mei Huang🇨🇳

    In this study, we employ a modified soft-wall holographic model with four flavors to investigate the meson spectra, decay constants, electromagnetic form factors, and charge radius of various mesons. We obtain the spectra for vector, axial vector, and pseudoscalar mesons. Decay constants are calculated and compared with experimental and lattice QCD data. The pion and kaon electromagnetic form factors are compared with the experimental data, and a good agreement is achieved for the kaon at low $Q^2$. For the charmed mesons, the electromagnetic form factors of the $D$ and $D_s$ and electric form factors of the $D^{\ast }$ and $D_s^{\ast }$ are well consistent with the lattice QCD data. Moreover, the electric, magnetic, and quadrupole form factors are predicted for the $\rho$, $K^{\ast }$, $a_1$, $K_1$, $D_1$, and $D_{s1}$ mesons. Furthermore, the charge radius of the vector, axial vector, and pseudoscalars, including the strange and charmed mesons, are computed.

    hep-phPRD(2023)·12 citations
11. 11*

    Octant Degeneracy and Plots of Parameter Degeneracy in Neutrino Oscillations Revisited

    Sho Sugama🇯🇵 · Osamu Yasuda🇯🇵

    The three kinds of parameter degeneracy in neutrino oscillation, the intrinsic, sign and octant degeneracy, form an eight-fold degeneracy. The nature of this eight-fold degeneracy can be visualized on the (${\sin }^{2}2{\theta }_{13}$, $1/{\sin }^2{\theta }_{23}$)-plane, through quadratic curves defined by $P({\nu }_{\mu }\to {\nu }_e)=$ const. and $P({\bar{\nu }}_{\mu }\to {\bar{\nu }}_e)=$ const., along with a straight line $P({\nu }_{\mu }\to {\nu }_{\mu })=$ const. After ${\theta }_{13}$ was determined by reactor neutrino experiments, the intrinsic degeneracy in ${\theta }_{13}$ transforms into an alternative octant degeneracy in ${\theta }_{23}$, which can potentially be resolved by incorporating the value of $P({\nu }_{\mu }\to {\nu }_{\mu })$. In this paper, we analytically discuss whether this octant parameter degeneracy is resolved or persists in the future long baseline accelerator neutrino experiments, such as T2HK, DUNE, T2HKK and ESS$\nu$SB. It is found that the energy spectra near the first oscillation maximum are effective in resolving the octant degeneracy, whereas those near the second oscillation maximum are not.

    hep-phPRD(2024)·2 citations
12. 12*

    $J/\psi$ and $\psi$(2S) polarization in proton-proton collisions at energies available at the CERN Large Hadron Collider using PYTHIA8

    Bhagyarathi Sahoo🇮🇳 · Dushmanta Sahu🇮🇳 · Suman Deb🇫🇷 · Captain R. Singh🇮🇳 · Raghunath Sahoo🇮🇳

    The production mechanisms of charmonium states in both hadronic and heavy-ion collisions hold great significance for investigating the hot and dense QCD matter. Studying charmonium polarization in ultra-relativistic collisions can also provide insights into the underlying production mechanisms. With this motivation, we explore the $J/\psi$ and $\psi$(2S) polarization in proton+proton collisions at $\sqrt{s}$ = 7, 8, and 13 TeV using a pQCD-inspired Monte-Carlo event generator called PYTHIA8. This work considers reconstructed quarkonia through their dimuons decay channel in the ALICE forward rapidity acceptance range of $2.5<y_{\mu \mu }<4$. Further, we calculate the polarization parameters ${\lambda }_{\theta }$, ${\lambda }_{\varphi }$, ${\lambda }_{\theta \varphi }$ from the polar and azimuthal angular distributions of the dimuons in helicity and Collins-Soper frames. This study presents a comprehensive measurement of the polarization parameters as a function of transverse momentum, charged-particle multiplicity, and rapidity at the LHC energies. Our findings of charmonium polarization are in qualitative agreement with the corresponding experimental data.

    hep-phhep-exnucl-exnucl-thPRC(2024)·16 citations
13. 13*

    New type of doubly charmed molecular pentaquarks containing most strange quarks: Mass spectra, radiative decays, and magnetic moments

    Fu-Lai Wang🇨🇳 · Xiang Liu🇨🇳

    In this work, we first predict the mass spectra of the ${\Omega }_c^{(\ast )}{D}_s^{(\ast )}$-type doubly charmed molecular pentaquark candidates, where the one-boson-exchange model is adopted by considering both the $S$-$D$ wave mixing effect and the coupled channel effect. Our findings indicate that the ${\Omega }_c{D}_s^{\ast }$ state with $J^P=1/2^{-}$, the ${\Omega }_c^{\ast }{D}_s^{\ast }$ state with $J^P=1/2^{-}$, and the ${\Omega }_c^{\ast }{D}_s^{\ast }$ state with $J^P=3/2^{-}$ can be considered as the most promising doubly charmed molecular pentaquark candidates, and the ${\Omega }_c{D}_s$ state with $J^P=1/2^{-}$, the ${\Omega }_c^{\ast }{D}_s$ state with $J^P=3/2^{-}$, and the ${\Omega }_c{D}_s^{\ast }$ state with $J^P=3/2^{-}$ are the possible doubly charmed molecular pentaquark candidates. Furthermore, we further explore the radiative decays and the magnetic moments of the most promising doubly charmed molecular pentaquark candidates in the constituent quark model. As a crucial aspect of spectroscopy, the information of the radiative decays and the magnetic moments can provide the valuable clues to reflect their inner structures. With the accumulation of higher statistical data at the Large Hadron Collider, we propose that the LHCb Collaboration should focus on the problem of searching for these predicted doubly charmed molecular pentaquark candidates containing most strange quarks in the coming years.

    hep-phPRD(2023)·17 citations
14. 14*

    Simulation of 3+1D glasma in Milne coordinates I: Development of the framework

    Hidefumi Matsuda🇨🇳 · Xu-Guang Huang🇨🇳

    We propose a new numerical method for $3+1$D glasma simulation using Milne coordinates. We formulate the classical Yang-Mills field and $3$D classical color current on a lattice at the initial proper time, specified as a moment just before the collision of the two nuclei. By solving the evolution equations, we extract observables of the $3$D glasma at later times. We demonstrate the efficiency of our method in terms of numerical cost and apply it to the central collisions of Au-Au. We also discuss possible further improvements of our method.

    hep-phnucl-thPRD(2023)·12 citations
15. 15*

    Constraining Axion and ALP Dark Matter from Misalignment during Reheating

    Yong Xu🇩🇪

    We explore the phenomenology of QCD axion and axion-like particle (ALP) dark matter production via misalignment during inflationary reheating. We investigate scenarios involving inflaton oscillating in a generic potential $\sim {\varphi }^n$, considering inflaton decay and annihilation for reheating. For low reheating temperatures, the parameter space leading to the correct relic abundance can be enlarged beyond the standard case. Depending on the type of inflaton-matter couplings and the value of $n$, we find that certain parts of the extended parameter space are already constrained by ADMX, CAPP, and MUSE experiments. Future Haloscope experiments are expected to impose stringent constraints. We highlight the potential to utilize axion experiments in constraining the dynamics of reheating.

    hep-phastro-ph.COPRD(2023)·19 citations
16. 16*

    Muon precession from the aspect of Dirac equations

    Jinbo He🇨🇳 · Lei Ming🇨🇳 · Yi-Lei Tang🇨🇳 · Qiankang Wang🇨🇳 · Hong-Hao Zhang🇨🇳

    In this paper, we would like to compute the muon anomalous precession frequency through solving the wave functions of the Dirac equations straightforwardly. The precession of a (anti-)muon with an anomalous magnetic momentum term is calculated together with the quantum corrections. Lorentz violation terms up to the lowest non-trivial order is introduced, and their effects on anomalous precession are evaluated perturbatively.

    hep-phhep-exNPB(2024)·0 citations
17. 17*

    Pionic and radiative transitions from $T_{c\bar{s}0}^{+}(2900)$ to $D_{s1}^{+}(2460)$ as a probe of the structure of $D_{s1}^{+}(2460)$

    Zi-Li Yue🇨🇳 · Cheng-Jian Xiao🇨🇳 · Dian-Yong Chen🇨🇳

    In this work, we evaluated the widths of the pionic and radiative transitions from the $T_{c\bar{s}0}^{+}(2900)$ to the $D_{s1}^{+}(2460)$ in the $D_{s1}^{+}(2460)$ molecular frame and the $D_{s1}^{+}(2460)$ charmed-strange meson frame. Our estimations demonstrate that the transition widths in the $D_{s1}^{+}(2460)$ molecular frame are much larger than those in the the $D_{s1}^{+}(2460)$ charmed-strange meson frame. Specifically, the ratio of the widths of $\Gamma (T_{c\bar{s}0}^{+}(2900)\to D_{s1}^{+}{\pi }^0)$ and $\Gamma (T_{c\bar{s}0}^{+}(2900)\to D^{+(0)}{K}^{0(+)})$ is estimated to be around 0.1 in the $D_{s1}^{+}(2460)$ charmed-strange meson frame, whereas the lower limit of this ratio is 0.67 in the $D_{s1}^{+}(2460)$ molecular frame. Thus, the aforementioned ratio could be employed as a tool for testing the nature of the $D_{s1}^{+}(2460)$.

    hep-phhep-exEPJC(2023)·7 citations
18. 18*

    Unraveling anomalies in Deeply Virtual Compton Scattering

    Shohini Bhattacharya🇺🇸 · Yoshitaka Hatta🇺🇸 · Werner Vogelsang🇩🇪

    We calculate the one-loop quark box diagrams relevant to polarized and unpolarized Deeply Virtual Compton Scattering by introducing an off-forward momentum $l^{\mu }$ as an infrared regulator. This regularization approach allows us to reveal the poles associated with the chiral anomaly in the polarized scenario, as well as the trace anomaly in the unpolarized case. We provide an interpretation of our findings in the context of pertinent Generalized Parton Distributions (GPDs). Furthermore, we discuss the implications of these poles on the QCD factorization pertaining to Compton amplitudes.

    hep-phnucl-th2 citations
19. 19*

    Non-thermal WIMP Production from Higher Order Moduli Decay

    Amitayus Banik🇩🇪 · Manuel Drees🇩🇪

    In a non-standard cosmological scenario, heavy, long-lived particles, which we call moduli, dominate the energy density prior to Big Bang Nucleosynthesis. Weakly Interacting Massive Particles (WIMPs) may be produced non-thermally from moduli decays. The final relic abundance then depends on additional parameters such as the branching ratio of moduli to WIMPs and the modulus mass. This is of interest for WIMP candidates, such as a bino-like neutralino, where thermal production in standard cosmology leads to an overdensity. Previous works have shown that the correct dark matter (DM) relic density can then still be obtained if the moduli, with mass less than $10^7$ GeV, decay to WIMPs with a branching ratio of less than $10^{-4}$. This upper bound could easily be violated once higher order corrections, involving final states with more than two particles, are included. We compute the branching ratios of three- and four-body decays of a modulus into final states involving two DM particles for general couplings. We then apply these expressions to sparticle production within the Minimal Supersymmetric Standard Model (MSSM) with neutralino DM. We find that this upper bound on the branching ratio can be satisfied in simplified models through an appropriate choice of as yet undetermined couplings. However, in the MSSM, it requires sparticle masses to be very close to half the modulus mass, in contrast to the idea of weak-scale supersymmetry.

    hep-phJCAP(2023)·4 citations
20. 20*

    Third order QCD predictions for fiducial W-boson production

    John Campbell🇺🇸 · Tobias Neumann🇺🇸

    Measurements of W-boson production at the LHC have reached percent-level precision and impose challenging demands on theoretical predictions. Such predictions directly limit the precision of measurements of fundamental quantities such as the W-boson mass and the weak mixing angle. A dominant source of uncertainty in predictions is from higher-order QCD effects. We present a calculation of W-boson production at the level of ${\alpha }_s^3$ at fixed order and including transverse-momentum resummation. We further show predictions for a direct comparison with low-pileup ATLAS transverse-momentum and fiducial cross-section measurements at $\sqrt{s}=5.02\text{ TeV}$. We discuss in detail the impact of modern PDFs. Our calculation including the matching to W+jet production at NNLO will be publicly available the upcoming CuTe-MCFM release and allows for theory-data comparison at the state-of-the-art level.

    hep-phhep-exJHEP(2023)·34 citations
21. 21*

    Geometry and unitarity of scalar fields coupled to gravity

    Minxi He🇯🇵 · Kohei Kamada🇯🇵 · Kyohei Mukaida🇯🇵

    We formulate scalar field theories coupled non-conformally to gravity in a manifestly frame-independent fashion. Physical quantities such as the $S$ matrix should be invariant under field redefinitions, and hence can be represented by the geometry of the target space. This elegant geometric formulation, however, is obscured when considering the coupling to gravity because of the redundancy associated with the Weyl transformation. The well-known example is the Higgs inflation, where the target space of the Higgs fields is flat in the Jordan frame but is curved in the Einstein frame. Furthermore, one can even show that any geometry of O$(N)$ nonlinear $\sigma$ models can be flattened by an appropriate Weyl transformation. In this Letter, we extend the notion of the target space by including the conformal mode of the metric, and show that the extended geometry provides a compact formulation that is manifestly Weyl-transformation/field-redefinition invariant. We identify the cutoff scale with the inverse of square root of the extended target space curvature and confirm that it coincides with that obtained from two-to-two scattering amplitudes based on our formalism.

    hep-phastro-ph.COhep-thPRL(2024)·8 citations
22. 22*

    Ratio of $J/\Psi$ and $\Psi (2s)$ exclusive photoproduction cross-sections as an indicator for the presence of non-linear QCD evolution

    Marco Alcazar Peredo🇲🇽 · Martin Hentschinski🇲🇽

    We investigate the proposal that the rise with energy of the ratio of the exclusive photo-production cross-sections of vector mesons $\Psi (2s)$ and $J/\Psi$ can serve as an indicator for the presence of high gluon densities and associated non-linear high energy evolution; we study this proposal for both photoproduction on a proton and a lead nucleus. While previous studies were based on unintegrated gluon distributions subject to linear (Balitsky-Fadin-Kuraev-Lipatov) and non-linear (Balitsky-Kovchegov) evolution equations, the current study is based on the Golec-Biernat Wüsthoff (GBW) and Bartels Golec-Biernat Kowalski (BGK) models, which allow assessing more directly the relevance of non-linear corrections for the description of the energy dependence of the photoproduction cross-section. We find that the rise of the ratio is directly related to the presence of a node in the $\Psi (2s)$ wave function and only manifests itself for the complete non-linear models, while it is absent for their linearized versions. We further provide predictions based on leading order collinear factorization and examine to which extent such an approach can mimic a ratio rising with energy. We also provide a description of recent ALICE data on the energy dependence of the photonuclear $J/\Psi$ production cross-section and give predictions for the energy dependence of the ratio of $\Psi (2s)$ and $J/\Psi$ photoproduction cross-sections for both scattering on a proton and a lead nucleus.

    hep-phPRD(2024)·22 citations
23. 23*

    Ripples of the QCD Critical Point

    Wei-jie Fu🇨🇳 · Xiaofeng Luo🇨🇳 · Jan M. Pawlowski🇩🇪 · Fabian Rennecke🇩🇪 · Shi Yin🇨🇳

    We investigate the impact of a critical end point (CEP) on the experimentally accessible baryon number fluctuations of different orders. By now, its potential location has been constrained fairly accurately within first principles functional QCD, together with the location of the chiral crossover line and further thermodynamic observables. This information is incorporated in an advanced QCD-assisted low energy effective theory which is used for the computation of baryon number fluctuations at the chemical freeze-out. This computation also takes care of global baryon number conservation at larger density, where the system changes from grand-canonical to canonical statistics. We observe a prominent peak structure, whose amplitude depends on the location of the CEP, while its position is more sensitive to the location of the freeze-out curve. Our results provide guidance for future low energy heavy-ion experiments.

    hep-phnucl-exnucl-thPRD(2025)·55 citations
24. 24*

    Testing high scale supersymmetry via second order gravitational waves

    Marcos M. Flores🇺🇸 · Alexander Kusenko🇺🇸 · Lauren Pearce🇺🇸 · Yuber F. Perez-Gonzalez🇬🇧 · Graham White🇬🇧

    Supersymmetry predicts multiple flat directions, some of which carry a net baryon or lepton number. Condensates in such directions form during inflation and later fragment into Q-balls, which can become the building blocks of primordial black holes. Thus supersymmetry can create conditions for an intermediate matter-dominated era with black holes dominating the energy density of the universe. Unlike particle matter, black holes decay suddenly enough to result in an observable gravitational wave signal via the poltergeist mechanism. We investigate the gravitational waves signatures of supersymmetry realized at energy scales that might not be accessible to present-day colliders.

    hep-phastro-ph.COPRD(2023)·9 citations
25. 25*

    Effective Field Theory for Extreme Mass Ratios

    Clifford Cheung🇺🇸 · Julio Parra-Martinez🇺🇸 · Ira Z. Rothstein🇺🇸 · Nabha Shah🇺🇸 · Jordan Wilson-Gerow🇺🇸

    We derive an effective field theory describing a pair of gravitationally interacting point particles in an expansion in their mass ratio, also known as the self-force (SF) expansion. The 0SF dynamics are trivially obtained to all orders in Newton's constant by the geodesic motion of the light body in a Schwarzschild background encoding the gravitational field of the heavy body. The corrections at 1SF and higher are generated by perturbations about this configuration -- that is, the geodesic deviation of the light body and the fluctuation graviton -- but crucially supplemented by an operator describing the recoil of the heavy body as it interacts with the smaller companion. Using this formalism we compute new results at third post-Minkowskian order for the conservative dynamics of a system of gravitationally interacting massive particles coupled to a set of additional scalar and vector fields.

    ↳ hep-thgr-qchep-phPRL(2024)·81 citations
26. 26*

    The Stochastic Gravitational-Wave Background from Primordial Black Holes in R-Symmetric $SU(5)$ Inflation

    Nadir Ijaz🇵🇰 · Maria Mehmood🇵🇰 · Mansoor Ur Rehman🇵🇰

    This study explores the realization of nonminimally coupled Higgs inflation in the context of no-scale supergravity, investigates the formation of primordial black holes, and examines the potential for observable proton decay within the framework of the R-symmetric $SU(5)$ model. For inflation, both single and multifield scenarios are investigated. The prediction of the single-field model for the tensor-to-scalar ratio, $r$, is approximately $10^{-3}$, and the scalar spectral index falls within Plank's 1$\sigma$ range. The running of the scalar spectral index, $-d{n}_s/d\ln k$, is approximately $10^{-4}$. A realistic scenario of reheating and non-thermal leptogenesis is employed with reheat temperature $T_r\sim 10^9$ GeV. In the multifield case, we mainly focus on Primordial Black Holes (PBHs) and Gravitational Waves (GWs). In this inflationary framework, we demonstrate how a suitable choice of parameters can result in an enhanced scalar power spectrum, leading to the production of primordial black holes (PBHs) capable of fully accounting for dark matter. We also show that this scenario leads to Scalar Induced Gravitational Waves (SIGW) which can be detected in current and future GW detectors. We explore different proton decay channels to look for observable predictions for the next-generation proton decay experiments Hyper-K and DUNE consistent with gauge coupling unification and cosmological bounds.

    ↳ astro-ph.COhep-phEPJC(2025)·19 citations
27. 27*

    Einstein vs Hawking: Black hole binaries and cosmological expansion

    Aurélien Barrau🇫🇷 · Baptiste Blachier🇧🇪 · Maxime Lahlou🇺🇸 · Andrew Liu🇫🇷 · Killian Martineau🇫🇷

    This note aims at investigating two different situations where the classical general relativistic dynamics competes with the evolution driven by Hawking evaporation. We focus, in particular, on binary systems of black holes emitting gravitational waves and gravitons, and on the cosmological evolution when black holes are immersed in their own radiation bath. Several non-trivial features are underlined in both cases.

    ↳ gr-qcastro-ph.COhep-phhep-thEPJC(2023)·2 citations
28. 28*

    High Energy Physics in Africa, Latin America and other developing regions

    Kétévi A. Assamagan🇺🇸 · Johan Sebastian Bonilla🇺🇸 · Claudio Dib🇨🇱 · Azwinndini Muronga🇿🇦 · Heath B. O'Connell🇺🇸 · Rogerio Rosenfeld🇧🇷 · Suyog Shrestha🇺🇸

    We summarize the current status of high energy physics (HEP) in Africa, Latin America, and other developing regions

    ↳ physics.soc-phhep-ph1 citation
29. 29*

    Are there any extragalactic high speed dark matter particles in the Solar neighborhood?

    Isabel Santos-Santos🇬🇧 · Nassim Bozorgnia🇨🇦 · Azadeh Fattahi🇬🇧 · Julio F. Navarro🇨🇦

    We use the APOSTLE suite of cosmological hydrodynamical simulations of the Local Group to examine the high speed tail of the local dark matter velocity distribution in simulated Milky Way analogues. The velocity distribution in the Solar neighborhood is well approximated by a generalized Maxwellian distribution sharply truncated at a well-defined maximum ``escape" speed. The truncated generalized Maxwellian distribution accurately models the local dark matter velocity distribution of all our Milky Way analogues, with no evidence for any separate extragalactic high-speed components. The local maximum speed is well approximated by the terminal velocity expected for particles able to reach the Solar neighborhood in a Hubble time from the farthest confines of the Local Group. This timing constraint means that the local dark matter velocity distribution is unlikely to contain any high-speed particles contributed by the Virgo Supercluster ``envelope", as argued in recent works. Particles in the Solar neighborhood with speeds close to the local maximum speed can reach well outside the virial radius of the Galaxy, and, in that sense, belong to the Local Group envelope posited in earlier work. The local manifestation of such envelope is thus not a distinct high-speed component, but rather simply the high-speed tail of the truncated Maxwellian distribution.

    ↳ astro-ph.GAastro-ph.COhep-phJCAP(2024)·8 citations
30. 30*

    Non-standard cosmic expansion histories: Neutrino decoupling and primordial nucleosynthesis signatures

    D. Aristizabal Sierra🇨🇱 · S. Gariazzo🇮🇹 · A. Villanueva🇨🇱

    Cosmological scenarios with a non-standard equation of state can involve ultrastiff fluids, understood as primordial fluids for which $p/\rho >1$. Their energy densities can dominate the Universe energy budget at early times, in the otherwise radiation dominated epoch. During that period the Universe undergoes a faster expansion, that has implications for any decoupling process that takes place in that era. Quintessence models or Ekpyrotic cosmologies are good examples of such scenarios. Assuming the ultrastiff state to be thermally decoupled at very early times, if ever coupled, its observational imprints are left solely in the Universe expansion rate and in the radiation energy density. We consider a complete set of ultrastiff fluids and study their signatures in the neutrino decoupling and BBN eras. Measurements of $N_{\text{eff}}$ alone place mild constraints on these scenarios, with forthcoming measurements from the Simons Observatory in the Chilean Atacama desert being able to test regions where still sizable effects are observable. However, when BBN data is taken into account, those regions are proven to be barely reconcilable with primordial helium-4 and deuterium abundances measurements. Our findings show that measurements of the primordial helium-4 abundance imply the tightest constraints, with measurements of primordial deuterium being -- to a certain extent -- competitive as well. We point out that a $\sim 60\%$ improvement on the statistical uncertainty of the primordial helium-4 abundance measurement, will test these scenarios in the region where they can produce sizable effects. Beyond that precision the regions that are accessible degenerate with standard expectations. In that case, although potentially present, neither neutrino decoupling nor BBN observables will be sensitive probes.

    ↳ astro-ph.COhep-phJCAP(2023)·5 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.