Fri·Sep 20, 2024Friday·September 20, 2024

1. 01*

   Resummed jet mass distribution with trimming in Z+jet events at the LHC

   Safa Gaid🇩🇿 · Yazid Delenda🇩🇿 · Rachik Soualah🇦🇪

   In this paper, we calculate the resummed jet mass distribution up to next-to-leading logarithmic accuracy for jets defined with the trimming groomer in Z+jet events at the LHC. We compute at fixed order and to all orders the large logarithms, both in the jet mass and $z_{\mathrm{cut}}$ trimming variable, including non-global and clustering logarithms. We conduct phenomenological studies at $\mathcal{O}({\alpha }_s)$, validating our results by comparing them with the fixed-order Monte Carlo program MCFM, which provides NLO predictions for hadron colliders. The resummation of non-global logarithms is estimated in the large-${\mathrm{N}}_{\mathrm{c}}$ limit. Our resummed result is compared to Monte Carlo parton shower simulations from Pythia 8, Herwig ++ and Sherpa 2 event generators.

   hep-phJHEP(2024)·2 citations
2. 02*

   Magnetized neutral 2SC color superconductivity and possible origin of the inner magnetic field of magnetars

   Shuai Yuan🇨🇳 · Bo Feng🇨🇳 · Efrain J. Ferrer🇺🇸 · Alejandro Pinero🇺🇸

   In this paper the neutral 2SC phase of color superconductivity is investigated in the presence of a magnetic field and for diquark coupling constants and baryonic densities that are expected to characterize neutron stars. Specifically, the behavior of the charged gluons Meissner masses is investigated in the parameter region of interest taking into account, in addition, the contribution of a rotated magnetic field. It is found that up to moderately-high diquark coupling constants the mentioned Meissner masses become tachyonic independently of the applied magnetic-field amplitude, hence signalizing the chromomagnetic instability of this phase. To remove the instability, the restructuring of the system ground state is proposed, which now will be formed by vortices of the rotated charged gluons. These vortices boost the applied magnetic field having the most significant increase for relatively low applied magnetic fields. Finally, considering that with the stellar rotational frequency observed for magnetars a field of the order of $10^8$ G can be generated by dynamo effect, we show that by the boosting effect just described the field can be amplified to $10^{17}$ G that is in the range of inner core fields expected for magnetars. Thus, we conclude that the described mechanism could be the one responsible for the large fields characterizing magnetars if the cores of these compact objects are formed by neutral 2SC matter.

   hep-phastro-ph.HEnucl-thPRD(2024)·5 citations
3. 03*

   SKA Sensitivity to Potential Radio Emission from Dark Matter Annihilation in Ursa Major III

   Peng-Long Zhang🇨🇳 · Xiao-Jun Bi🇨🇳 · Qin Chang🇨🇳 · Peng-Fei Yin🇨🇳 · Yi Zhao🇨🇳

   The recently discovered stellar system, Ursa Major III/UNIONS 1, may be the faintest and densest dwarf spheroidal satellite galaxy of the Milky Way. Owing to its close proximity and substantial dark matter (DM) component, Ursa Major III emerges as a highly promising target for DM indirect detection. It is known that electrons and positrons originating from DM annihilation can generate a broad radio spectrum through the processes of synchrotron radiation and inverse Compton scattering within galaxies. In this study, we investigate the potential of the Square Kilometre Array (SKA) in detecting radio signatures arising from DM annihilation in Ursa Major III over a 100 hour observation period. Our analysis indicates that the SKA has strong capabilities in detecting these signatures. For instance, the SKA sensitivity to the DM annihilation cross section is estimated to reach $\mathcal{O}(10^{-30})-\mathcal{O}(10^{-28})\mathrm{c}{\mathrm{m}}^3{\mathrm{s}}^{-1}$ in the DM mass range from several GeV to $\sim 100$ GeV for the $e^{+}{e}^{-}$ and ${\mu }^{+}{\mu }^{-}$ annihilation channels. The precise results are significantly influenced by various astrophysical factors, such as the strength of magnetic field, the diffusion coefficient, and the DM density profile in the dwarf galaxy. We discuss the impact of the uncertainties associated with these factors, and find that the SKA sensitivities have the potential to surpass the current constraints, even when considering these uncertainties.

   hep-phPRD(2024)·2 citations
4. 04*

   Baryon number transportation over full rapidity space in pp collisions at LHC energies

   Banajit Barman🇮🇳 · Nur Hussain🇮🇳 · Buddhadeb Bhattacharjee🇮🇳

   The estimation of anti-baryon to baryon ratio is considered to be a useful tool for studying baryon number transport in pp, pA and AA collisions. For this study, the Pythia event generator with various tunes is used to measure the $\text{Anti}-Lamda$/$\text{Lamda}$ ratio as a function of rapidity (y), transverse momentum (pT ), and multiplicity within both ALICE and LHCb acceptances. The results obtained using various MC data for pp collisions at \sqrt{s} = 7 TeV are compared with the experimentally measured values of $\text{Anti}-Lamda$/$\text{Lamda}$ ratio of ALICE and LHCb experiments. Out of the various studied tunes of Pythia 8.3, the string junction model is found to be the most successful in describing the experimentally observed results. Evidence of a considerable amount of baryon number transportation from the beam fragmentation to the ALICE and LHCb acceptances could be recognised.

   hep-phPRC(2025)·3 citations
5. 05*

   Non-Holomorphic Modular ${\mathcal{A}}_4$ Symmetric Scotogenic Model

   Takaaki Nomura🇨🇳 · Hiroshi Okada🇨🇳 · Oleg Popov🇨🇳

   The present work extends scotogenic and its modular ${\mathcal{A}}_4$ variation a step forward and demonstrates scotogenic modular ${\mathcal{A}}_4$ non-supersymmetric realization. To achieve this non-holomorphic modular symmetries come to rescue. Advantage of the current construction is the compactness of the model content and absence of the supersymmetric fields. Neutrino mass is generated through a canonical scotogenic mechanism. The allowed values of the VEV of the $\tau$ modulus are $\tau \simeq w$ and Im$[\tau ]\approx 2$. The non-holomorphic modular ${\mathcal{A}}_4$ symmetry leads to correlations among the neutrino observables.

   hep-phPLB(2025)·27 citations
6. 06*

   Is Tokenization Needed for Masked Particle Modelling?

   Matthew Leigh🇨🇭 · Samuel Klein🇨🇭 · François Charton🇫🇷 · Tobias Golling🇨🇭 · Lukas Heinrich🇩🇪 · Michael Kagan🇺🇸 · Inês Ochoa🇵🇹 · Margarita Osadchy🇮🇱

   In this work, we significantly enhance masked particle modeling (MPM), a self-supervised learning scheme for constructing highly expressive representations of unordered sets relevant to developing foundation models for high-energy physics. In MPM, a model is trained to recover the missing elements of a set, a learning objective that requires no labels and can be applied directly to experimental data. We achieve significant performance improvements over previous work on MPM by addressing inefficiencies in the implementation and incorporating a more powerful decoder. We compare several pre-training tasks and introduce new reconstruction methods that utilize conditional generative models without data tokenization or discretization. We show that these new methods outperform the tokenized learning objective from the original MPM on a new test bed for foundation models for jets, which includes using a wide variety of downstream tasks relevant to jet physics, such as classification, secondary vertex finding, and track identification.

   hep-phcs.LG33 citations
7. 07*

   Potential of Neutrino Telescopes to Detect Quantum Gravity-Induced Decoherence in the Presence of Dark Fermions

   Alba Domi🇩🇪 · Thomas Eberl🇩🇪 · Dominik Hellmann🇩🇪 · Sara Krieg🇩🇪 · Heinrich Päs🇩🇪

   We assess the potential of neutrino telescopes to discover quantum-gravity-induced decoherence effects modeled in the open-quantum system framework and with arbitrary numbers of active and dark fermion generations, such as particle dark matter or sterile neutrinos. The expected damping of neutrino flavor oscillation probabilities as a function of energy and propagation length thus encodes information about quantum gravity effects and the fermion generation multiplicity in the dark sector. We employ a public Monte-Carlo dataset provided by the IceCube Collaboration to model the detector response and estimate the sensitivity of IceCube to oscillation effects in atmospheric neutrinos induced by the presented model. Our findings confirm the potential of very-large-volume neutrino telescopes to test this class of models and indicate higher sensitivities for increasing numbers of dark fermions.

   hep-phhep-exJCAP(2025)·4 citations
8. 08*

   T-odd observables from anomalous $tbW$ couplings in single-top production at an $ep$ collider

   Saurabh D. Rindani🇮🇳

   We investigate the possibility that an imaginary anomalous $tbW$ coupling can be measured in the process $e^{-}p\to {\nu }_e\overline{t}X$ by means of T-odd observables. One such observable considered here is the polarization of the top antiquark transverse to the production plane. The other is a T-odd correlation constructed out of observable momenta when the top quark decays leptonically. Both these T-odd observables are shown to be proportional to the imaginary part of only one of the $tbW$ anomalous couplings, the other couplings giving either vanishing or negligible contribution. This imaginary part could signal either a CP-odd coupling, or an absorptive part in the effective coupling, or both. We estimate the 1-$\sigma$ limits that might be derived in the case of each of these observables for a collider with a proton energy of 7 TeV and an electron energy of 60 GeV and also in the case of a higher electron energy of 150 GeV.

   hep-phhep-exPLB(2024)·1 citation
9. 09*

   The \pi^+\pi^- Coulomb interaction study and its use in the data processing

   B.Adeva (1)🇪🇸 · L.Afanasyev (2)🇷🇺 · A.Anania (3)🇮🇹 · S.Aogaki (4)🇷🇴 · A.Benelli (5)🇨🇿 · V.Brekhovskikh (6)🇷🇺 · T.Cechak (5)🇨🇿 · M.Chiba (7)🇯🇵 · P.Chliapnikov (6)🇷🇺 · D.Drijard (5 and 8)🇨🇿 · A.Dudarev (2)🇷🇺 · D.Dumitriu (4)🇷🇴 and 43 other authors

   In this work the Coulomb effects (Coulomb correlations) in ${\pi }^{+}{\pi }^{-}$ pairs produced in p + Ni collisions at 24 GeV/$c$, are studied using experimental ${\pi }^{+}{\pi }^{-}$ pair distributions in $Q$, the relative momentum in the pair center of mass system (c.m.s), and its projections $Q_L$ (longitudinal component) and $Q_t$ (transverse component) relative to the pair direction in the laboratory system (l.s.). The $Q$, $Q_L$, and $Q_t$ distributions of the {\sl Coulomb pairs} in the c.m.s. have been simulated assuming they are described by the phase space modified by the known point-like Coulomb correlation function $A_C(Q)$, corrected for small effects due to the nonpoint-like pair production and the strong two-pion interaction. The same distributions of {\sl non-Coulomb pairs} have been simulated according to the phase space, but without $A_C(Q)$. It is shown that the number of {\sl Coulomb pairs} in all $Q_t$ intervals, including the small $Q_t$ (small opening angles $\theta$ in the l.s.) is calculated with the theoretical precision better than 2\%. The comparison of the simulated and experimental numbers of {\sl Coulomb pairs} at small $Q_t$ allows us to check and correct the detection efficiency for the pairs with small $\theta$ (0.06 mrad and smaller). It is shown that {\sl Coulomb pairs} can be used as a new physical tool to check and correct the quality of the simulated events. The special property of the {\sl Coulomb pairs} is the possibility of checking and correcting the detection efficiency, especially for the pairs with small opening angles.

   hep-phhep-exPRD(2024)·0 citations
10. 10*

    Medium modifications of heavy-flavor jet angularities in high-energy nuclear collisions

    Yao Li🇨🇳 · Shi-Yong Chen🇨🇳 · Wei-Xi Kong🇨🇳 · Sa Wang🇨🇳 · Ben-Wei Zhang🇨🇳

    We present the first theoretical study of heavy-flavor jet angularities (${\lambda }_{\alpha }^{\kappa }$) in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=$ 5.02 TeV. The initial production of heavy-flavor jets is carried out using the POWHEG+PYTHIA8 prescription, while the jet evolution in the quark-gluon plasma (QGP) is described by the SHELL transport model. In p+p collisions, we observe narrower angularity distributions for D${}^0$-tagged jets compared to inclusive jets, consistent with the ALICE preliminary results. We then demonstrate that jet quenching in the QGP slightly widens the angularity distribution of D${}^0$-tagged jets in Pb+Pb collisions relative to that in p+p collisions for jet transverse momentum of $10<p_{\mathrm{T},\mathrm{jet}}<20$ GeV/c, while the angularity distributions of inclusive and D${}^0$-tagged jets become narrower in Pb+Pb collisions relative to p+p at $p_{\mathrm{T},\mathrm{jet}}>20$ GeV/c due to the strong influence of the selection bias. Additionally, by comparing the average angularities $⟨{\lambda }_{\alpha }^{\kappa }⟩$ of inclusive, D${}^0$-tagged and B${}^0$-tagged jets with varying $\alpha$ and $\kappa$, we show that the larger the quark mass is, the lower the jet's $⟨{\lambda }_{\alpha }^{\kappa }⟩$ values are. As a result of the slenderer initial distribution, we predict that as compared to inclusive jets, the heavy-flavor jets, especially the B${}^0$-tagged ones, will suffer stronger modifications of $⟨{\lambda }_{\alpha }^{\kappa }⟩$ in Pb+Pb relative to p+p at $10<p_{\mathrm{T},\mathrm{jet}}<20$ GeV/c. For a larger jet radius, a more significant broadening of jet angularities is predicted because of the enhanced contributions of the wide-angle particles.

    hep-phnucl-thChin.Phys.Lett.(2025)·9 citations
11. 11*

    Implication of the Weizsacker-Williams approximation for the dark matter mediator production

    I. V. Voronchikhin🇷🇺 · D. V. Kirpichnikov🇷🇺

    The simplified connection between Standard Model (SM) particles and light dark matter (LDM) can be introduced via spin-0 and spin-1 lepton-specific mediators. Moreover, in a mediator mass range from sub-MeV to sub-GeV, fixed-target facilities such as NA64$e$, LDMX, NA64$\mu$, and M${}^3$ can potentially probe such particles of the hidden sector via missing energy signatures that are described by the bremsstrahlung-like process involving leptons. We compare the Weizsaker-Williams (WW) approximation and the exact tree-level (ETL) approach for the bremsstrahlung-like mediator production cross section by choosing various parameters of the fixed-target experiments. We show that the relative difference between the total cross sections calculated in the WW and ETL approximation varies from $\mathcal{O}(1)\%$ to $\mathcal{O}(10)\%$ for a muon mode and from $\mathcal{O}(-20)\%$ to $\mathcal{O}(80)\%$ for an electron mode. We argue that the main difference between two approaches for electron beam mode arises from peak forward region of the cross section. We also discuss the impact of parametrization of nuclear and atomic elastic form-factors on the total cross section. In particular, we show that the employing different form-factor parametrization can lead to a uncertainty in the cross section at the level of $\lesssim \mathcal{O}(10)\%$. That study may be helpful for the lepton fixed-target experiments that examine the bremsstrahlung-like production of the DM mediators.

    hep-phPRD(2025)·7 citations
12. 12*

    Discovery potential of a long-lived partner of inelastic dark matter at MATHUSLA in $U(1{)}_{X_3}$ extension of the standard model

    Nobuchika Okada🇺🇸 · Osamu Seto🇯🇵

    We investigate the discovery potential at the MATHUSLA experiment of a long-lived particle (LLP), which is the heavier state of inelastic scalar dark matter (DM) in third generation-philic $U(1)$ ($U(1{)}_{X_3}$) extension of the standard model. Since the heavier state and DM state form the complex scalar charged under the $U(1{)}_{X_3}$, it is natural that the heavier state $P$ is almost degenerate with the DM state and hence long-lived. We find that third generation-philic right-handed $U(1)$, $U(1{)}_{R_3}$, model is the most interesting, because third generation-philic models are less constrained by the current experimental results and right-handed $U(1)$ interactions leave visible final decay products without produing neutrinos. For a benchmark of the model parameters consistent with the current phenomenological constraints, we find that the travel distance of the LLP can be $\mathcal{O}(100)$ m and the LLP production cross section at the 14 TeV LHC can be $\mathcal{O}(10)$ fb. Thus, we conclude that the LLP can be discovered at the MATHUSLA with a sufficiently large number of LLP decay events inside the MATHUSLA detector.

    hep-phastro-ph.COPTEP·2 citations
13. 13*

    Hadronic scattering effects on $\psi (2S)$ suppression in relativistic heavy-ion collisions

    L. M. Abreu🇧🇷 · F. S. Navarra🇧🇷 · H. P. L. Vieira🇧🇷

    In this work we estimate the $N_{\psi (2S)}/N_{J/\psi }$ yield ratio in heavy-ion collisions, considering the interactions of the $\psi (2S)$ and $J/\psi$ states with light mesons in the hadron gas formed at the late stages of these collisions. Starting from the appropriate effective Lagrangians, we first compute the thermally-averaged cross sections for the production and absorption of the mentioned states, and then use them as input in the rate equations to determine the time evolution of $N_{\psi (2S)}$, $N_{J/\psi }$ and $N_{\psi (2S)}/N_{J/\psi }$. The main conclusion of our study is that the $\psi (2S)$ and $J/\psi$ multiplicities do not change much in the hadron gas phase and that the $\psi (2S)$ is more absorbed than the $J/\psi$. The obtained final ratio is in qualitative agreement with experimental data.

    hep-phPLB(2025)·3 citations
14. 14*

    Isolating New Physics signatures of vectorlike quarks and heavy Higgses over multi $b$-jet backgrounds

    Enrico Lunghi🇺🇸 · Beni Pazar🇺🇸

    We discuss models in which vectorlike quarks and a second Higgs doublet are simultaneously present and couple to the third generation of SM quarks. A general feature of these models is that cascade decays of vectorlike fermions into heavy Higgses (or vice versa, depending on their masses) dominate their respective branching ratios. The resulting collider signals involve a large multiplicity of $b$-jets and offer formidable experimental challenges. We present a detailed and realistic analysis of the expected sensitivity of dedicated searches at ATLAS and CMS.

    hep-phhep-exEPJC(2025)·0 citations
15. 15*

    Flavor Hierarchy of Jet Energy Correlators inside the Quark-Gluon Plasma

    Wen-Jing Xing🇨🇳 · Shanshan Cao🇨🇳 · Guang-You Qin🇨🇳 · Xin-Nian Wang🇨🇳

    Heavy flavor jets provide ideal tools to probe the mass effect on jet substructure in both vacuum and quark-gluon plasma (QGP). Energy-energy correlator (EEC) is an excellent jet substructure observable owning to its strong sensitivity to jet physics at different scales. We perform a complete realistic simulation on medium modification of heavy and light flavor jet EEC in heavy-ion collisions. A clear flavor hierarchy is observed for jet EEC in both vacuum and QGP due to the mass effect. The medium modification of inclusive jet EEC at different angular scales exhibits very rich structure: suppression at intermediate angles, and enhancement at small and large angles, which can be well explained by the interplay of mass effect, energy loss, medium-induced radiation and medium response. These unique features of jet EEC are shown to probe the physics of jet-medium interaction at different scales, and can be readily validated by upcoming experiments.

    hep-phnucl-exnucl-thPRL(2025)·40 citations
16. 16*

    Through the Looking Glass into the Dark Dimension: Searching for Bulk Black Hole Dark Matter with Microlensing of X-ray Pulsars

    Luis A. Anchordoqui🇺🇸 · Ignatios Antoniadis🇹🇭 · Dieter Lust🇩🇪 · Karem Peñaló Castillo🇺🇸

    Primordial black holes (PBHs) hidden in the incredible bulk of the dark dimension could escape constraints from non-observation of their Hawking radiation. Since these five-dimensional (5D) PBHs are bigger, colder, and longer-lived than usual 4D PBHs of the same mass $M$, they could make all cosmological dark matter if $10^{11}\lesssim M/\mathrm{g}\lesssim 10^{21}$, i.e., extending the 4D allowed region far down the asteroid-mass window. We show that these evasive PBHs could be search for by measuring their $X$-ray microlensing events from faraway pulsars. We also show that future $X$-ray microlensing experiments will be able to probe the interesting range ($10^{16.5}\lesssim M/\mathrm{g}\lesssim 10^{17.5}\mathrm{g}$) where an all dark matter interpretation in terms of 4D Schwarzschild PBHs is excluded by the non-observation of their Hawking radiation.

    hep-phPhys.Dark Univ.(2024)·16 citations
17. 17*

    SModelS v3: Going Beyond Z2 Topologies

    Mohammad Mahdi Altakach🇫🇷 · Sabine Kraml🇫🇷 · Andre Lessa🇧🇷 · Sahana Narasimha🇦🇹 · Timothée Pascal🇫🇷 · Camila Ramos🇧🇷 · Yoxara Villamizar🇧🇷 · Wolfgang Waltenberger🇦🇹

    SModelS is a public tool for fast reinterpretation of LHC searches for new physics based on a large database of simplified model results. While previous versions were limited to models with a Z2-type symmetry, such as R-parity conserving supersymmetry, version 3 can now handle arbitrary signal topologies. To this end, the tool was fully restructured and now relies on a graph-based description of simplified model topologies. In this work, we present the main conceptual changes and novel features of SModelS v3, together with the inclusion of new experimental searches for resonant production of spin-1 and spin-0 mediators with decays to quarks or to dark matter. Applying these results to a model containing two mediators, we discuss the interplay of resonance and missing energy searches, and the model's coverage by the currently available simplified model results.

    hep-phhep-exJHEP(2024)·26 citations
18. 18*

    On the family discrimination in 331-model

    Katri Huitu🇫🇮 · Niko Koivunen🇪🇪 · Timo Kärkkäinen🇪🇪 · Subhadeep Mondal🇮🇳

    In the so-called 331-models the gauge anomalies cancel only if there are three generations of fermions. This requires one of the quark generations to be in a different representation than the other two. But which generation is treated differently? In this work we study how the choice of differently treated generation effects the quark flavour structure and how the discriminated generation can be deduced from experiments. We study a general model based on $\beta =-1/\sqrt{3}$, which contains exotic quarks with same electric charges as SM quarks. We take fully into account the effects from exotic quark mixing with the SM quarks, which is often omitted in literature. We will also pay particular attention to $125$ GeV Higgs, and show analytically why its flavour violating couplings between SM quarks are suppressed.

    hep-phJHEP(2025)·5 citations
19. 19*

    String Invention, Viable 3-3-1 Model, Dark Matter Black Holes

    Holger B. Nielsen🇩🇰

    After very little memories we review slightly Paul Frampton's memories from the discovery of Veneziano model being indeed string theory with Y. Nambu and secondly his 3-3-1 theory.This latter is an indeed not excluded replacement for the Standard Model with triangle anomalies cancelling as they must in a truly viable theory. It even needs (essentially) 3 as the family number! Also primordial black holes as dark matter is mentioned, we end with review of a my own very speculative utterly recent idea, that for the purpose of the classical approximation, we could, using the functional integral as our rudimentary assumption taken over from quantum mechanics, obtain the equations of motion without the in our opinion very mysterious imaginary unit i, which usually occurs as a factor in the exponent of the functional integrand, which is this i times the action. The functional integral without the mysterious i leads to predicting some of the most strong features in cosmology, and also seems to argue for as little black holes as possible.

    hep-phhep-thEntropy(2024)·4 citations
20. 20*

    On the Gravitational Wave Counterpart to a Gamma-ray Galactic Center Signal from Millisecond Pulsars

    Kayla Bartel🇺🇸 · Stefano Profumo🇺🇸

    The new tools of gravitational wave and multi-messenger astronomy allow for the study of astrophysical phenomenon in new ways and enables light to be shed on some of the longest-enduring mysteries of high-energy astrophysics. Among the latter stands the Galactic center gamma-ray excess, associated with a source whose nature could be annihilating dark matter or a yet-unresolved population of millisecond pulsars (MSPs). MSPs are most likely asymmetric about their axis of rotation, and are thus thought to also source quasi-monochromatic gravitational waves, that dark matter processes would not emit. Using statistical methods, we simulate realistic MSP population samples with differing morphology and moment of inertia, that could give rise to the gamma-ray excess, and we compute the corresponding gravitational wave signal amplitude and frequency. We find that the gravitational wave signal frequency likely ranges between $\sim$200 and 1400 Hz, and that the collective dimensionless strain from the center of the Galaxy has an amplitude between $10^{-26}$ and $10^{-24}$, thus most likely beyond current and near-term detectors, unless the unresolved MSPs are extraordinarily gamma-ray dim.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2024)·6 citations
21. 21*

    Analytic two-Loop four-point form factor of the stress-tensor supermultiplet in $\mathcal{N}=4$ SYM

    Yuanhong Guo🇨🇳 · Lei Wang🇨🇳 · Gang Yang🇨🇳 · YiXiong Yin🇨🇳

    We compute the two-loop four-point MHV form factor of the stress-tensor supermultiplet in planar $\mathcal{N}=4$ super Yang-Mills (SYM). This form factor is analogous to the Higgs plus four-gluon amplitudes in the heavy-top limit of QCD when translated to the $\mathcal{N}=4$ SYM context. We obtain the full $D$-dimensional integrands up to two loops via unitarity-cut methods. Subsequently, we utilize IBP reduction to express the result in terms of a set of uniformly transcendental basis integrals, incorporating the two-loop non-planar five-point one-mass integrals recently given by Abreu et al. [PRL 132 (2024) 14]. We obtain the two-loop finite remainder in the functional form in terms of the pentagon functions. The symbol of our remainder confirms the bootstrap results reported by Dixon et al. [PRL 130 (2023) 11]. We perform various non-trivial checks of our results, including the triple-collinear limit, which recovers the two-loop six-gluon remainder. We also show that the form factor has a directional dual conformal symmetry at the integrand level. Our results are expected to shed further light on the study of antipodal dualities and the computation of Higgs plus four-parton amplitudes in QCD.

    ↳ hep-thhep-phJHEP(2025)·8 citations
22. 22*

    Mixed phases of compact star matter in a unified mean-field approach

    Cheng-Jun Xia🇨🇳 · Toshiki Maruyama🇯🇵 · Nobutoshi Yasutake🇯🇵 · Toshitaka Tatsumi🇯🇵

    Based on an extended NJL model that treats baryons as clusters of quarks, we investigate the properties and microscopic structures of mixed phases for various types of first-order phase transitions in a unified manner, where the model parameters are fixed by reproducing nuclear matter properties and the binding energies of finite nuclei. In particular, based on the Thomas-Fermi approximation, we investigate the mixed phases arise from the liquid-gas phase transition of nuclear matter, chiral phase transition, and deconfinement phase transition in dense stellar matter adopting spherical and cylindrical approximations for the Wigner-Seitz cells. It is found that the geometrical structures do not emerge for chiral phases transition, while the droplet, rod, slab, tube, and bubble phases emerge sequentially as density increases for the liquid-gas and deconfinement phase transitions. Additional attractive interactions between strange quark matter and hyperons are observed as the deconfinement phase transition is entangled with chiral phase transition of $s$ quarks. The results obtained here should be useful to understand the properties and structures of dense stellar matter throughout compact stars and in particular the matter state in the core regions. Meanwhile, more extensive investigations in a three-dimensional geometry with large box sizes are necessary for our future study.

    ↳ nucl-thhep-phPRD(2024)·4 citations
23. 23*

    Notes on Selection Rules of Canonical Differential Equations and Relative Cohomology

    Jiaqi Chen🇨🇳 · Bo Feng🇨🇳

    We give an explanation of the $\mathrm{d}\log$-form of the coefficient matrix of canonical differential equations using the projection of ($n$+1)-$\mathrm{d}\log$ forms onto $n$-$\mathrm{d}\log$ forms. This projection is done using the leading-order formula for intersection numbers. This formula gives a simple way to compute the coefficient matrix. When combined with the relative twisted cohomology, redundancy in computation using the regulator method can be avoided.

    ↳ hep-thhep-phJHEP(2025)·5 citations
24. 24*

    Detecting Hyperons in neutron stars -- a machine learning approach

    Valéria Carvalho🇵🇹 · Márcio Ferreira🇵🇹 · Constança Providência🇵🇹

    We present a neural network classification model for detecting the presence of hyperonic degrees of freedom in neutron stars. The models take radii and/or tidal deformabilities as input and give the probability for the presence of hyperons in the neutron star composition. Different numbers of observations and different levels of uncertainty in the neutron star properties are tested. The models have been trained on a dataset of well-calibrated microscopic equations of state of neutron star matter based on a relativistic mean-field formalism. Real data and data generated from a different description of hyperonic matter are used to test the performance of the models.

    ↳ nucl-thastro-ph.HEhep-phPRD(2024)·7 citations
25. 25*

    Shaping Dark Photon Spectral Distortions

    Giorgi Arsenadze🇺🇸 · Andrea Caputo🇨🇭 · Xucheng Gan🇺🇸 · Hongwan Liu🇺🇸 · Joshua T. Ruderman🇺🇸

    The cosmic microwave background (CMB) spectrum is an extraordinary tool for exploring physics beyond the Standard Model. The exquisite precision of the measurement makes it particularly sensitive to small effects caused by hidden sector interactions. In particular, CMB spectral distortions can unveil the existence of dark photons which are kinetically coupled to the standard photon. In this work, we use the COBE-FIRAS dataset to derive accurate and robust limits on photon-to-dark-photon oscillations for a large range of dark photon masses, from $10^{-10}$ to $10^{-4}$ eV. We consider in detail the redshift dependence of the bounds, computing CMB distortions due to photon injection/removal using a Green's function method. Our treatment improves on previous results, which had set limits studying energy injection/removal into baryons rather than photon injection/removal, or ignored the redshift evolution of distortions. The difference between our treatment and previous ones is particularly noticeable in the predicted spectral shape of the distortions, a smoking gun signature for photon-to-dark-photon oscillations. The characterization of the spectral shape is crucial for future CMB missions, which could improve the present sensitivity by orders of magnitude, exploring regions of the dark photon parameter space that are otherwise difficult to access.

    ↳ astro-ph.COhep-phJHEP(2025)·19 citations
26. 26*

    Stochastic Axion-like Curvaton: Non-Gaussianity and Primordial Black Holes Without Large Power Spectrum

    Chao Chen🇨🇳 · Anish Ghoshal🇵🇱 · Gianmassimo Tasinato🇬🇧 · Eemeli Tomberg🇪🇪

    We discuss a mechanism of primordial black hole (PBH) formation that does not require specific features in the inflationary potential, revisiting previous literature. In this mechanism, a light spectator field evolves stochastically during inflation and remains subdominant during the post-inflationary era. Even though the curvature power spectrum stays small at all scales, rare perturbations of the field probe a local maximum in its potential, leading to non-Gaussian tails in the distribution of curvature fluctuations, and to copious PBH production. For a concrete axion-like particle (ALP) scenario we analytically determine the distribution of the compaction function for perturbations, showing that it is characterized by a heavy tail, which produces an extended PBH mass distribution. We find the ALP mass and decay constant to be correlated with the PBH mass, for instance, an ALP with a mass $m_a=5.4\times 10^{14}$ eV and a decay constant $f_a=4.6\times 10^{-5}Mpl$ can lead to PBHs of mass $M_{\mathrm{PBH}}=10^{21}$ g as the entire dark matter (DM) of the universe, and is testable in future PBH observations via lensing in the NGRST and mergers detectable in the LISA and ET Gravitational Waves (GW) detectors. We then extend our analysis to mixed ALP and PBH dark matter and Higgs-like spectator fields. We find that PBHs cluster strongly over all cosmological scales, clashing with CMB isocurvature bounds. We argue that this problem is shared by all PBH production from inflationary models that depend solely on large non-Gaussianity without a peak in the curvature power spectrum and discuss possible remedies.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2025)·16 citations
27. 27*

    Updated Cosmological Constraints in Extended Parameter Space with Planck PR4, DESI Baryon Acoustic Oscillations, and Supernovae: Dynamical Dark Energy, Neutrino Masses, Lensing Anomaly, and the Hubble Tension

    Shouvik Roy Choudhury🇹🇼 · Teppei Okumura🇹🇼

    We present updated constraints on cosmological parameters in a 12-parameter model, extending the standard six-parameter $\Lambda$CDM by including dynamical dark energy (DE: $w_0$, $w_a$), the sum of neutrino masses ($\sum m_{\nu }$), the effective number of non-photon radiation species ($N_{\mathrm{eff}}$), the lensing amplitude scaling ($A_{\mathrm{lens}}$), and the running of the scalar spectral index (${\alpha }_s$). For CMB data, we use the Planck PR4 (2020) HiLLiPoP and LoLLiPoP likelihoods, Planck PR4+ACT DR6 lensing, and Planck 2018 low-$l$ TT likelihoods, along with DESI DR1 BAO and Pantheon+ and DESY5 uncalibrated type Ia Supernovae (SNe) likelihoods. Key findings are the following: i) Contrary to DESI results, CMB+BAO+Pantheon+ data include a cosmological constant within $2\sigma$, while CMB+BAO+DESY5 excludes it at over $2\sigma$, indicating the dynamical nature of dark energy is not yet robust. Potential systematics in the DESY5 sample may drive this exclusion. ii) Some data combinations show a $1\sigma$+ detection of non-zero $\sum m_{\nu }$, indicating possible future detection. We also provide a robust upper bound of $\sum m_{\nu }\lesssim 0.3$ eV (95% confidence limit (C.L.)). iii) With CMB+BAO+SNe, $A_{\mathrm{lens}}=1$ is included at $2\sigma$ (albeit not at $1\sigma$), indicating no significant lensing anomaly in this extended cosmology with Planck PR4 likelihoods. iv) The Hubble tension persists at $3.2$ to $3.9\sigma$, suggesting these simple extensions do not resolve it. v) The $S_8$ tension with DES Year 3 weak lensing is reduced to $1.4\sigma$, likely due to additional parameters and the Planck PR4 likelihoods.

    ↳ astro-ph.COhep-phApJL(2024)·191 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.