Wed·Oct 9, 2024Wednesday·October 9, 2024

1. 01*

   Tracing the bottom electroweak dipole operators at future lepton colliders

   Jiayin Gu🇨🇳 · Jiayu Guo🇨🇳 · Xiao-Ze Tan🇨🇳

   While often omitted in the SMEFT analyses of electroweak measurements, the electroweak dipole operators of the bottom quark have been found to be important in some cases and are also related to processes involving the top quark. In this paper, we further investigate their effects, focusing on the measurements of the $e^{+}{e}^{-}\to b\bar{b}$ process at a future lepton collider. Their linear contributions are suppressed by the bottom mass due to the helicity flip in the interference term with the SM amplitude, leading to a nontrivial interplay between the linear and the quadratic contributions. With two runs at the Z-pole and 240 GeV, the effects of CP-even dipole coefficients can be well separated from the modifications of the SM $Zb\bar{b}$ couplings, while an additional run (e.g. at 360 GeV) is useful for lifting a nontrivial second best-fit point due to the quadratic contributions.

   hep-phJHEP(2025)·3 citations
2. 02*

   Heavy Flavour Jet Substructure

   Prasanna K. Dhani🇪🇸 · Oleh Fedkevych🇺🇸 · Andrea Ghira🇮🇹 · Simone Marzani🇮🇹 · Gregory Soyez🇫🇷

   We present a comprehensive study of energy correlation functions and jet angularities for heavy-flavour QCD jets. In particular, we discuss the possibility of using these observables to expose the dead cone effect, i.e. the suppression of collinear QCD radiation around massive quarks, and to investigate the sensitivity of different observable definitions to the presence of quark masses. Our calculations are presented as all-order resummed predictions at next-to-leading-logarithmic accuracy, matched to (partial) fixed-order results to obtain a better description of the transition around the dead cone threshold. We also compare our analytic results with Pythia, Herwig and Sherpa Monte Carlo predictions to estimate the impact of non-perturbative contributions such as hadronisation, underlying events and $B$-hadron decays.

   hep-phJHEP(2025)·18 citations
3. 03*

   Searching for Gluino LSP at the LHC

   Paulina Knees🇦🇷 · Essodjolo Kpatcha🇪🇸 · Iñaki Lara🇵🇱 · Daniel E.López-Fogliani🇦🇷 · Carlos Muñoz🇪🇸 · Natsumi Nagata🇯🇵 · Hidetoshi Otono🇯🇵

   We analyse relevant signals expected at the LHC, assuming that the gluino is the lightest supersymmetric particle (LSP) in the framework of the $\mu \nu$SSM. In this $R$-parity violating model, the presence of couplings involving right-handed neutrinos solves simultaneously the $\mu$ problem and the accommodations of neutrino masses and mixing angles. We study gluino pair production in quark-antiquark and gluon-gluon collisions. The main decay channels for the gluino LSP are the three-body decays to two quarks and a lepton or a neutrino. In both cases, the leading channels occur for the third family of quarks. We compare the predictions of this scenario with LHC searches for prompt and long-lived particles. To analyse the parameter space we sample the $\mu \nu$SSM for a gluino LSP, paying special attention to reproduce the current experimental data on neutrino and Higgs physics, as well as flavour observables. Our results imply a lower limit on the mass of the gluino LSP of about 2600 GeV, and an upper limit for the decay length of about 6 cm.

   hep-phhep-exEPJC(2025)·2 citations
4. 04*

   Highly Excited Electron Cyclotron for QCD Axion and Dark-Photon Detection

   Xing Fan🇺🇸 · Gerald Gabrielse🇺🇸 · Peter W. Graham🇺🇸 · Harikrishnan Ramani🇺🇸 · Samuel S. Y. Wong🇺🇸 · Yawen Xiao🇺🇸

   We propose using highly excited cyclotron states of a trapped electron to detect meV axion and dark photon dark matter, marking a significant improvement over our previous proposal and demonstration [Phys. Rev. Lett. 129, 261801]. When the axion mass matches the cyclotron frequency ${\omega }_c$, the cyclotron state is resonantly excited, with a transition probability proportional to its initial quantum number, $n_c$. The sensitivity is enhanced by taking $n_c\sim 10^6{\left(\frac{0.1\text{meV}}{{\omega }_c}\right)}^2$. By optimizing key experimental parameters, we minimize the required averaging time for cyclotron detection to $t_{\text{ave}}\sim 10^{-6}$ seconds, permitting detection of such a highly excited state before its decay. An open-endcap trap design enables the external photon signal to be directed into the trap, rendering our background-free detector compatible with large focusing cavities, such as the BREAD proposal, while capitalizing on their strong magnetic fields. Furthermore, the axion conversion rate can be coherently enhanced by incorporating layers of dielectrics with alternating refractive indices within the cavity. Collectively, these optimizations enable us to probe the QCD axion parameter space from 0.1 meV to 2.3 meV (25-560 GHz), covering a substantial portion of the predicted post-inflationary QCD axion mass range. This sensitivity corresponds to probing the kinetic mixing parameter of the dark photon down to $ϵ\approx 2\times 10^{-16}$.

   hep-phastro-ph.COhep-exphysics.atom-ph+1PRD(2025)·25 citations
5. 05*

   Thermomagnetic effects on light pseudo-scalar meson masses within the SU(3) Nambu-Jona--Lasinio model

   Máximo Coppola🇦🇷 · William R. Tavares🇧🇷 · Sidney S. Avancini🇧🇷 · Joana C. Sodré🇧🇷 · Norberto N. Scoccola🇦🇷

   We calculate the screening masses of pseudoscalar mesons in a hot and strongly magnetized medium within the framework of the SU(3) Nambu-Jona--Lasinio model, using a magnetic field-independent regularization scheme. Inverse magnetic catalysis (IMC) is implemented through the use of a magnetic field-dependent coupling $G(B)$, fitted to reproduce lattice quantum chromodynamics (QCD) results for the pseudocritical chiral transition temperature $T_c^B$. For the external homogeneous magnetic field considered, neutral screening masses separate in two types: perpendicular and parallel to the direction of the field, while for charged mesons only parallel energies can be defined for each Landau level. We obtain $m_{\mathrm{scr},\perp }>m_{\mathrm{scr},\parallel }$, as expected from causality. Thermally, all screening energies are almost constant until some critical temperature, whose behavior is correlated with $T_c^B$. They rapidly increase around this value, keeping a steady enhancement afterward due to thermal excitation. Magnetically, neutral parallel masses are enhanced (suppressed) at high temperatures when considering $G(B)$ ($G$). Perpendicular ones display a non-monotonic magnetic behavior for $G$ (due to increasing $T_c^B$) when $T\lesssim 500$~MeV, but become magnetically enhanced when $T\gtrsim 500$~MeV. For $G(B)$ they always increase with $B$. Charged parallel energies are always magnetically enhanced, for both couplings. In the high-temperature limit, we show that both neutral and charged screening energies converge to $2\pi T$. At $B=0$ the model overestimates the remaining quark interaction in this regime. At $B\ne 0$ we find that, when IMC is accounted for, the interaction is suppressed as $B$ increases, a fact that appears to be at odds with currently available lattice QCD results.

   hep-phhep-latPRD(2024)·6 citations
6. 06*

   Diffractive photoproduction of dark photons

   Jan Cepila🇨🇿 · Jesús Guillermo Contreras🇨🇿

   Dark photons serve as a portal to connect the dark and standard model sectors. Here, we propose photon-induced exclusive diffractive processes as a new tool to study the production of dark photons in current and future colliders. These processes join the strength of the strong force, yielding large cross sections, with the cleanliness of diffractive photoproduction, providing a clean experimental environment. Although the measurement would be extremely difficult, we identified a currently unexplored region around dark photon masses of 1 GeV/$c^2$ and coupling suppression $\epsilon$ values around $10^{-4}$ where dark photons could be potentially found at the LHC.

   hep-ph0 citations
7. 07*

   Exotic hybrid pseudopotentials at finite temperature and chemical potential

   Le Zhang🇨🇳 · Fei-Yang Cai🇨🇳 · Xun Chen🇨🇳

   Using gauge/gravity duality, we study the exotic hybrid pseudopotentials at finite temperature and chemical potential. The $\Sigma$ hybrid meson can be described by a model including an object called ``defect'' on a string linking the quark and antiquark. It was first proposed by Andreev and perfectly described the ${\Sigma }_u^{-}$ hybrid potential at zero temperature and chemical potential. In this paper, we would like to extend this model to finite chemical potential and compare the separate distance and pseudopotentials of ${\Sigma }_g^{+}$ and ${\Sigma }_u^{-}$. Unlike ${\Sigma }_g^{+}$ ground state, the ${\Sigma }_u^{-}$ hybrid pseudopotentials no longer behave as Coulomb-like at short distances. In addition, temperature and chemical potential have a significant impact on the ${\Sigma }_u^{-}$ hybrid pseudopotentials. The screen distances and hybrid pseudopotentials of ${\Sigma }_u^{-}$ significantly decrease with the increase of temperature and chemical potential. At last, we draw the melting diagram of ${\Sigma }_g^{+}$ and ${\Sigma }_u^{-}$ in the $T-\mu$ plane, and confirm that the quark-antiquark pair in ${\Sigma }_u^{-}$ excited state is easier to melt than in ${\Sigma }_g^{+}$ ground state.

   hep-phCPC(2025)·2 citations
8. 08*

   Analysis of neutrino oscillation parameters in the light on quantum entanglement

   Rajrupa Banerjee🇮🇳 · Papia Panda🇮🇳 · Rukmani Mohanta🇮🇳 · Sudhanwa Patra🇮🇳

   Numerous neutrino experiments have confirmed the phenomenon of neutrino oscillation, providing direct evidence of the quantum mechanical nature of neutrinos. In this work, we investigate the entanglement properties of neutrino flavor states within the framework of three-flavor neutrino oscillation using two major entanglement measures: entanglement of formation (EOF) and concurrence, utilizing the DUNE experimental setup. Our findings indicate that the maximally entangled state appears between ${\nu }_{\mu }$ and ${\nu }_{\tau }$ whereas, ${\nu }_e$ behaves as a nearly separable state. To further explore the nature of bipartite entanglement, we introduce the concept of the monogamy of entanglement, which allows us to investigate the distinction between genuine three-flavor entanglement and bipartite entanglement. Our analysis confirms that the three-flavor neutrino system forms a bipartite entanglement structure, adhering to the Coffman-Kundu-Wootters (CKW) inequality. Additionally, we implement a minimization procedure to find the best-fit values of the oscillation parameters that correspond to the concurrence minima at the two specific energy points where the concurrence reaches its lowest values. Using these best-fit values, we probe three fundamental unknowns in neutrino oscillation: CP violation sensitivity, neutrino mass hierarchy, and the octant issue of ${\theta }_{23}$, across two distinct energy points. Our results manifest that while the best-fit values obtained through concurrence minimization show slightly reduced sensitivity to CP violation compared to current best-fit values, they exhibit greater sensitivity to the mass hierarchy. Furthermore, the study reveals a maximal mixing angle for the atmospheric sector.

   hep-phNPB(2026)·10 citations
9. 09*

   The $X(4500)$ state considered as the mixture of hadronic molecule and diquark-antidiquark within effective field theory

   De-Shun Zhang🇨🇳 · Wei He🇨🇳 · Chu-Wen Xiao🇨🇳 · Zhi-Feng Sun🇨🇳

   In the present work, we construct the Lagrangians including three-meson, meson-diquark-antidiquark vertices, such that the diquark-antidiquark component as well as the molecular component are introduced within the effective field theory. With the obtained effective potentials projecting to spin 0, 1 and 2, we solve the Bethe-Salpeter equation with the on-shell approximation, and find that $X(4500)$ can be explained as the mixture of components $D_s^{\ast +}{D}_s^{\ast -}$, $A_{cq}{\bar{A}}_{cq}$ and $A_{cs}{\bar{A}}_{cs}$ with $I^G(J^{PC})=0^{+}(0^{++})$. In addition, another two resonances with quantum numbers $I^G(J^{PC})=0^{+}(1^{++})$ and $I^G(J^{PC})=0^{+}(2^{++})$ are predicted.

   hep-phhep-ex2 citations
10. 10*

    Comment on "Neutrino oscillations originate from virtual excitation of $Z$ bosons" and "Neutrinos produced from $\beta$ decays of neutrons cannot be in coherent superpositions of different mass eigenstates"

    James M. Cline🇨🇦

    It was recently claimed (arxiv:2407.00954) that neutrino oscillations through conventional mass mixing are forbidden by energy conservation, and that they in fact arise from virtual $Z$ boson exchange. I explain why both claims, and therefore a repetition of these claims in arxiv:2410.03133, are incorrect.

    hep-ph2 citations
11. 11*

    Recent progress in transverse momentum dependent (TMD) Parton Densities and corresponding parton showers

    S. Taheri Monfared🇩🇪

    The parton branching method is crucial for Monte Carlo generators, which are essential for high-energy physics predictions. We examine the impact of soft gluons on inclusive collinear and Transverse Momentum Dependent (TMD) parton densities. By applying the Parton-Branching (PB) method, we identify the non-perturbative Sudakov form factor with the integration range $z\to 1$, which is often neglected in collinear parton shower approaches. The significance of soft gluons is demonstrated through the transverse momentum spectrum of Drell-Yan lepton pairs, resulting in an intrinsic-$k_t$ distribution width that remains independent of $\sqrt{(}s)$, contrary to observations in collinear parton shower approaches. This behavior is attributed to the non-perturbative Sudakov form factor.

    hep-phPoS(2025)·2 citations
12. 12*

    High-${\mathrm{p}}_{\mathrm{T}}$ LHC constraints on SMEFT operators affecting rare kaon and hyperon decays

    Arnab Roy🇦🇺 · German Valencia🇦🇺

    We consider the constraints on new physics affecting rare kaon and hyperon decay as parametrized by a low energy effective theory that can be obtained from high-${\mathrm{p}}_{\mathrm{T}}$ observables at LHC. To this end, we match the relevant low energy Wilson coefficients onto those in SMEFT at dimension six and compute their contributions to charged dilepton, monolepton, monojets, and $\mathrm{VH}$ searches by ATLAS and CMS. Constraints from rare kaon decays are generally more restrictive, with the ones arising from high-${\mathrm{p}}_{\mathrm{T}}$ measurements complementing them along directions in parameter space to which the former are not sensitive. We also illustrate the effect of a high luminosity LHC run in reducing the viable parameter regions.

    hep-phJHEP(2025)·6 citations
13. 13*

    Off-shell $t\bar{t}{W}^{+}j$ production at NLO QCD accuracy

    Minos Reinartz🇩🇪

    We report on our recent full off-shell $pp\to t\bar{t}{W}^{+}j+X$ calculation at the NLO level in QCD. Unstable resonant particles like the $W^{\pm }/Z$ vector bosons and top quarks are modelled with Breit-Wigner propagators. Furthermore double-, single- and non-resonant contributions as well as all their interference terms are consistently included at the matrix element level. We provide integrated and differential (fiducial) cross-section results and investigate the size of theoretical uncertainties as well as the impact of renormalization- and factorization scale settings on the theoretical predictions. Finally, we explore the effects of additional jet activity in $t\bar{t}{W}^{+}$ production and top-quark decays.

    hep-phPoS(2025)·0 citations
14. 14*

    Four top final states with NLO accuracy in perturbative QCD: 3 lepton channel

    Nikolaos Dimitrakopoulos🇩🇪 · Malgorzata Worek🇩🇪

    We examine the effect of higher-order QCD corrections on the four top-quark production cross section in the $3$ lepton decay channel. Top-quark and $W$ gauge-boson decays are included at next-to-leading order in perturbative QCD. The narrow-width approximation, that preserves spin correlations, is used to perform the calculation for this complex $2\to 12(13)$ process. We present differential cross-section distributions of top-quark decay products for the LHC Run III energy of $\sqrt{s}=13.6$ TeV, using realistic selection cuts. Our results show that QCD corrections and jet radiation in top-quark and $W$ decays can lead to significant changes in shapes of basic kinematic distributions and, therefore, need to be included for the accurate description of $pp\to t\bar{t}t\bar{t}+X$ process in the $3\ell$ decay channel. The NLO QCD results obtained in this work are important in the context of the recent observation of the $pp\to t\bar{t}t\bar{t}+X$ process by the ATLAS and CMS collaborations and are of great significance for the High-Luminosity phase of the LHC.

    hep-phhep-exJHEP(2025)·5 citations
15. 15*

    The QED nonfactorizable correction to the semileptonic charmed three-body $B$ decays

    Yueling Yang🇨🇳 · Liting Wang🇨🇳 · Jiazhi Li🇨🇳 · Qin Chang🇨🇳 · Junfeng Sun🇨🇳

    In this paper, the nonfactorizable photonic corrections to the effective four-fermion vertex for the $\overline{B}$ $\to$ $D^{(\ast )}$ $+$ ${\ell }^{-}$ $+$ ${\bar{\nu }}_{\ell }$ decays are considered at the quark level within SM, where $\ell$ $=$ $e$, $\mu$ and $\tau$. It is found that the QED corrections are closely related with the mass of the charged lepton. The QED contributions will enhance branching ratios, which results in the slight reduction of ratios $R(D^{(\ast )})$ and the relationship $R(D^{(\ast )}{)}_e$ $<$ $R(D^{(\ast )}{)}_{\mu }$.

    hep-phhep-exEPJC(2024)·1 citation
16. 16*

    Binwise exploration of vector couplings in $B_s\to D_s^{(\ast )}\tau {\bar{\nu }}_{\tau }$ decays

    Ajay Kumar Yadav🇮🇳 · Suchismita Sahoo🇮🇳

    Recent results from the LHCb experiment have confirmed that lepton flavor universality is upheld in flavor-changing neutral current processes, such as $B\to K^{(\ast )}{l}^{+}{l}^{-}$. However, discrepancies remain in the charged current sector, raising questions about the universality of lepton flavors in these processes. To explore this issue, we investigate the decays $B_s\to D_s^{(\ast )}\tau {\bar{\nu }}_{\tau }$ in different $q^2$ bins, which involve the $b\to c\tau {\bar{\nu }}_{\tau }$ transition. We employ a model-independent approach to analyze potential new physics by fitting both real and complex (axial)vector coefficients to the existing $b\to (u,c)\tau {\bar{\nu }}_{\tau }$ data. Our analysis enables us to calculate the branching ratios and angular distributions for the $B_s\to D_s^{(\ast )}\tau {\bar{\nu }}_{\tau }$ decays in four different $q^2$ bins. Additionally, we evaluate whether lepton flavor universality is maintained in these charged current decays or if deviations suggest the presence of new physics.

    hep-phNPB(2025)·1 citation
17. 17*

    YFS Exponentiation -- Gate to Precision Accelerator Physics Experiments

    B.F.L. Ward (Baylor University, Waco, TX, USA)🇺🇸

    We present the history and current status of the YFS Monte Carlo approach to precision theory for accelerator physics experiments. Key contributions of Prof. Stanislaw Jadach are highlighted

    hep-phActa Phys. Pol. B Proceedings Supplement …·0 citations
18. 18*

    Force-feeding Supermassive Black Holes with Dissipative Dark Matter

    Matthew R. Buckley🇺🇸 · Nicolas Fernandez🇺🇸

    Supermassive black holes with masses $\gtrsim 10^9{M}_{\odot }$ have been discovered by JWST at high redshifts ($z\sim 7$). It is difficult to explain such objects as the result of accretive growth of stellar-mass seeds, as the rate at which baryons can be fed to the black hole is limited by the radiation pressure of the infalling matter. In this paper, we propose a new mechanism to create the early progenitors: the collapse of small dark matter halos through a dissipative cooling mechanism in the dark sector. These small black holes can then be efficiently fed with additional dissipative dark matter due to the comparatively weak interactions between the dark radiation and dark matter, which results in a very short Eddington time and high accretion rates.

    hep-phastro-ph.GAJCAP(2025)·6 citations
19. 19*

    Holography and the internal structure of charmonium

    Nelson R. F. Braga🇧🇷 · Yan F. Ferreira🇧🇷 · William S. Cunha🇧🇷

    Holographic models that consider classical vector fields in a 5-d background provide successful effective descriptions for heavy vector meson spectra. This holds both in the vacuum and in a thermal medium, like the quark gluon plasma. However, it is somehow mysterious the way that these phenomenological models work. In particular, what is the role of the fifth dimension and what is the relation between the holographic 5-d background and the physical (4-d) heavy mesons. Hadrons, in contrast to leptons, are composite particles with some internal structure, that depends on the energy at which they are observed. In this work, a static meson is represented by a heavy quark-antiquark pair with an interaction described by a Nambu Goto string living in the same 5-d background that provides field solutions leading to masses and decay constants of charmonium states. The interaction potential that shows up is linear for large distances with a string tension consistent with the effective Cornell potential. Introducing temperature $T$ in the background it is found, for the $J/\psi$ case, that there is a deconfining transition at some critical value of $T$. The results obtained indicate that the 5-d background is effectively representing the internal structure of the (static) charmonium (quasi) states.

    hep-phhep-thCPC(2025)·2 citations
20. 20*

    Susy breaking soft terms in the supersymmetric Pati-Salam landscape from Intersecting D6-Branes

    Mudassar Sabir🇨🇳 · Adeel Mansha🇨🇳 · Tianjun Li🇨🇳 · Zhi-Wei Wang🇨🇳

    We investigate the supersymmetry breaking soft terms for all the viable models in the complete landscape of three-family supersymmetric Pati-Salam models arising from intersecting D6-branes on a ${\mathbb{T}}^6/({\mathbb{Z}}_2\times {\mathbb{Z}}_2)$ orientifold in type IIA string theory. The calculations are performed in the general scenario of $u$-moduli dominance with the $s$-moduli turned on, where the soft terms remain independent of the Yukawa couplings and the Wilson lines. The results for the trilinear coupling, gaugino-masses, squared-mass parameters of squarks, sleptons and Higgs depend on the brane wrapping numbers and the susy breaking parameters. We find that unlike the Yukawa couplings which remain unchanged for the models dual under the exchange of two SU(2) sectors, the corresponding soft term parameters only match for the trilinear coupling and the mass of the gluino. This can be explained by the internal geometry where the Yukawa interactions depend only on the triangular areas of the worldsheet instantons while the soft terms have an additional dependence on the orientation-angles of D6-branes in the three two-tori. In the special limit of parameter space we find universal masses for the Higgs and the gauginos.

    hep-phhep-thJHEP(2025)·5 citations
21. 21*

    The Hypertriton Puzzle in Relativistic Heavy-Ion Collisions

    Thomas Cohen🇺🇸 · Maneesha Pradeep🇺🇸

    The yields of hadrons and light nuclei in relativistic collisions of heavy-nuclei at a center of mass energy of 2.6 TeV can be described remarkably well by a thermal distribution of an ideal gas of hadrons and light nuclei interacting only via the decay of resonances. Given the particularly small binding energy of hypertritons relative to the temperature describing the yields (about 156 MeV), one might naturally expect hypertrions to dissociate in medium, making the agreement of hypertriton yields with thermal predictions highly puzzling. The puzzle is compounded by the fact that small binding energy is associated with the large size of the hypertriton. This size is on a similar scale to the overall size of the fireball and much larger than the length scale over which temperatures in the fireball vary over phenomenologically relevant amounts. This paper quantifies the tension this effect causes and shows that it is sufficiently large to render the thermal model inconsistent: its natural assumptions are in conflict with its outputs. The possibility that hypertritons are formed at freeze out as compact objects, quark droplets, that subsequently evolve into hypertritons is considered as a way to resolve the puzzle. It is noted that beyond making the assumption that compact quark droplets form, additional detailed dynamical assumptions which have not been justified are needed to make the thermal model work. The issue of why, despite these issues, the hypertriton is well described by a simple statistical description at freeze out is unresolved. Resolving the hypertriton puzzle is important as it may clarify whether the phenomenological success of the simple thermal model for yields accurately reflects the simple picture of the underlying physics on which it is based.

    ↳ nucl-thhep-phPRC(2025)·3 citations
22. 22*

    Comparison between the emission torus and the measured toroidal magnetic field for the Crab and Vela nebula

    Wei Deng🇨🇳 · Fei Xie · Kuan Liu · Mingyu Ge · Youli Tuo🇩🇪 · Fabio La Monaca · Alessandro Di Marco · En-wei Liang🇨🇳

    Polarization measurements provide insight into the magnetic field, a critical aspect of the dynamics and emission properties around the compact object. In this paper, we present the polarized magnetic field of the Crab outer torus and the Vela arc utilizing Imaging X-ray Polarimetry Explorer observation data. The polarization angle (PA) measured for the Crab outer torus exhibits two monotonic evolutions along the azimuth angle, which are consistent with the normal line of the elliptical ring. There is a slight increase in PA along the azimuth angle for both the inner arc and the outer arc of the Vela nebula. The polarized magnetic vector along the outer torus of the Crab nebula shows the polarized magnetic field aligns with Crab outer torus structure. The PA variation along the Crab outer torus suggests a bulk flow speed of 0.8c. Meanwhile, the Vela nebula polarized magnetic field does not exactly align with the Vela arc structure. We noted that the Crab nebula possesses a polarized toroidal magnetic field, where as the Vela nebula exhibits an incomplete toroidal magnetic field.

    ↳ astro-ph.SRastro-ph.GAastro-ph.HEhep-phApJ(2024)·2 citations
23. 23*

    Modular symmetry of localized modes

    Tatsuo Kobayashi🇯🇵 · Hajime Otsuka🇯🇵 · Shohei Takada🇯🇵 · Hikaru Uchida🇯🇵

    We study the modular symmetry of localized modes on fixed points of $T^2/{\mathbb{Z}}_2$ orbifold. First, we find that the localized modes with even (odd) modular weight generally have $\Delta (6n^2)$ (${\Delta }^{\prime }(6n^2)$) modular flavor symmetry. Moreover, when we consider an additional Ansatz, the localized modes with even (odd) modular weight generally enjoy $S_3$ ($S_4^{\prime }$) modular flavor symmetry, and we show the concrete wave functions of the localized modes.

    ↳ hep-thhep-phPRD(2024)·4 citations
24. 24*

    Everything hot everywhere all at once: Neutrinos and hot dark matter as a single effective species

    Amol Upadhye🇦🇺 · Markus R. Mosbech🇩🇪 · Giovanni Pierobon🇦🇺 · Yvonne Y. Y. Wong🇦🇺

    Observational cosmology is rapidly closing in on a measurement of the sum M_nu of neutrino masses, at least in the simplest cosmologies, while opening the door to probes of non-standard hot dark matter (HDM) models. By extending the method of effective distributions, we show that any collection of HDM species, with arbitrary masses, temperatures, and distribution functions, including massive neutrinos, may be represented as a single effective HDM species. Implementing this method in the FlowsForTheMasses non-linear perturbation theory for free-streaming particles, we study non-standard HDM models that contain thermal QCD axions or generic bosons in addition to standard neutrinos, as well as non-standard neutrino models wherein either the distribution function of the neutrinos or their temperature is changed. Along the way, we substantially improve the accuracy of this perturbation theory at low masses, bringing it into agreement with the high-resolution TianNu neutrino N-body simulation to about 2% at k = 0.1 h/Mpc and to within 21% up to k = 1 h/Mpc. We accurately reproduce the results of simulations including axions and neutrinos of multiple masses. Studying the differences between the normal, inverted, and degenerate neutrino mass orderings on their non-linear power, we quantify the error in the common approximation of degenerate masses. We release our code publicly at http://github.com/upadhye/FlowsForTheMassesII .

    ↳ astro-ph.COhep-phJCAP(2025)·5 citations
25. 25*

    One trick to treat them all: SuperEasy linear response for any hot dark matter in $N$-body simulations

    Giovanni Pierobon🇦🇺 · Markus R. Mosbech🇩🇪 · Amol Upadhye🇦🇺 · Yvonne Y. Y. Wong🇦🇺

    We generalise the SuperEasy linear response method, originally developed to describe massive neutrinos in cosmological $N$-body simulations, to any hot dark matter (HDM) species with arbitrary momentum distributions. The method uses analytical solutions of the HDM phase space perturbations in various limits and constructs from them a modification factor to the gravitational potential that tricks the cold particles into trajectories as if HDM particles were present in the simulation box. The modification factor is algebraic in the cosmological parameters and requires no fitting. Implementing the method in a Particle-Mesh simulation code and testing it on HDM cosmologies up to the equivalent effect of $\sum m_{\nu }=0.315$ eV-mass neutrinos, we find that the generalised SuperEasy approach is able to predict the total matter and cold matter power spectra to $\lesssim 0.1\%$ relative to other linear response methods and to $\lesssim 0.25\%$ relative to particle HDM simulations. Applying the method to cosmologies with mixed neutrinos\Plus{}thermal QCD axions and neutrinos\Plus{}generic thermal bosons, we find that non-standard HDM cosmologies have no intrinsically different non-linear signature in the total matter power spectrum from standard neutrino cosmologies. However, because they predict different time dependencies even at the linear level and the differences are augmented by non-linear evolution, it remains a possibility that observations at multiple redshifts may help distinguish between them.

    ↳ astro-ph.COhep-phJCAP(2024)·4 citations
26. 26*

    Eclipse Dynamics and X-ray Burst Characteristics in the Low-Mass X-ray Binary EXO 0748-676

    Nirpat Subba · Nishika Subba · Jyoti Paul · Pankaj Sharma · Monika Ghimiray

    This study investigates the timing and spectral characteristics of X-ray bursts from the neutron star system EXO 0748-676 using the NuSTAR observatory's FPMA and FPMB instruments in the 3-79 keV range. We identify Type I X-ray bursts driven by thermonuclear explosions on the neutron star's surface, notably a significant burst at \(X = 18,479.97\), indicating rapid energy release, followed by a recoil burst at \(X = 19,463.97\), reflecting stabilization. The correlation between burst timing and the neutron star's optical period suggests modulation by its rotation and periodic accretion dynamics. Spectral modeling reveals a photon index of \( \Gamma = 1.24 \pm 0.014 \) and a cutoff energy of \( E_C = 36.20 \pm 1.04 \; \text{keV} \), indicating a hot corona around the neutron star. The measured flux of approximately \( (381.17 \pm 0.014) \times 10^{-12} \; \text{erg cm}^{-2} \text{s}^{-1} \) underscores the dynamic nature of accretion-driven systems. Calculated luminosities derived from distance estimates range from \( (3.86 \pm 0.239) \times 10^{36} \; \text{erg/s} \) to \( (2.3 \pm 0.177) \times 10^{36} \; \text{erg/s} \). Comparative analysis with prior observations from the IBIS/ISGRI instrument on the INTEGRAL satellite shows variability in emission characteristics, including softer photon indices and higher cutoff energies in 2003 and 2004. Our examination of smaller energy gaps (3-7 keV, 7-12 keV, etc.) reveals energy-dependent behavior in burst characteristics, enhancing our understanding of nuclear burning phases. Overall, these findings validate models describing Type I X-ray bursts and lay the groundwork for future investigations into similar astrophysical systems and stellar evolution processes in extreme environments.

    ↳ astro-ph.HEhep-phphysics.data-an2 citations
27. 27*

    QCD deconfinement transition line up to ${\mu }_B=400$ MeV from finite volume lattice simulations

    Szabolcs Borsanyi🇩🇪 · Zoltan Fodor🇩🇪 · Jana N. Guenther🇩🇪 · Paolo Parotto🇮🇹 · Attila Pasztor🇭🇺 · Ludovica Pirelli🇩🇪 · Kalman K. Szabo🇩🇪 · Chik Him Wong🇩🇪

    The QCD cross-over line in the temperature ($T$) -- baryo-chemical potential (${\mu }_B$) plane has been computed by several lattice groups by calculating the chiral order parameter and its susceptibility at finite values of ${\mu }_B$. In this work we focus on the deconfinement aspect of the transition between hadronic and Quark Gluon Plasma (QGP) phases. We define the deconfinement temperature as the peak position of the static quark entropy ($S_Q(T,{\mu }_B)$) in $T$, which is based on the renormalized Polyakov loop. We extrapolate $S_Q(T,{\mu }_B)$ based on high statistics finite temperature ensembles on a $16^3\times 8$ lattice to finite density by means of a Taylor expansion to eighth order in ${\mu }_B$ (NNNLO) along the strangeness neutral line. For the simulations the 4HEX staggered action was used with 2+1 flavors at physical quark masses. In this setup the phase diagram can be drawn up to unprecedentedly high chemical potentials. Our results for the deconfinement temperature are in rough agreement with phenomenological estimates of the freeze-out curve in relativistic heavy ion collisions. In addition, we study the width of the deconfinement crossover. We show that up to ${\mu }_B\approx 400$ MeV, the deconfinement transition gets broader at higher densities, disfavoring the existence of a deconfinement critical endpoint in this range. Finally, we examine the transition line without the strangeness neutrality condition and observe a hint for the narrowing of the crossover towards large ${\mu }_B$.

    ↳ hep-lathep-phnucl-thPRD(2024)·28 citations
28. 28*

    Limits on planetary-mass primordial black holes from the OGLE high-cadence survey of the Magellanic Clouds

    Przemek Mróz🇵🇱 · Andrzej Udalski🇵🇱 · Michał K. Szymański · Igor Soszyński · Paweł Pietrukowicz · Szymon Kozłowski · Radosław Poleski · Jan Skowron · Krzysztof Ulaczyk · Mariusz Gromadzki · Krzysztof Rybicki · Patryk Iwanek · Marcin Wrona · Mateusz J. Mróz

    Observations of the Galactic bulge revealed an excess of short-timescale gravitational microlensing events that are generally attributed to a large population of free-floating or wide-orbit exoplanets. However, in recent years, some authors suggested that planetary-mass primordial black holes (PBHs) comprising a substantial fraction (1%-10%) of the dark matter in the Milky Way may be responsible for these events. If that was the case, a large number of short-timescale microlensing events should also be seen toward the Magellanic Clouds. Here, we report the results of a high-cadence survey of the Magellanic Clouds carried out from 2022 October through 2024 May as part of the Optical Gravitational Lensing Experiment. We observed almost 35 million source stars located in the central regions of the Large and Small Magellanic Clouds and found only one long-timescale microlensing event candidate. No short-timescale events were detected despite high sensitivity to such events. That allows us to infer the strongest available limits on the frequency of planetary-mass PBHs in dark matter. We find that PBHs and other compact objects with masses from $1.4\times 10^{-8}{M}_{\odot }$ (half of the Moon mass) to $0.013M_{\odot }$ (planet/brown dwarf boundary) may comprise at most 1% of dark matter. That rules out the PBH origin hypothesis for the short-timescale events detected toward the Galactic bulge and indicates they are caused by the population of free-floating or wide-orbit planets.

    ↳ astro-ph.COastro-ph.EPastro-ph.GAastro-ph.SR+3ApJL(2024)·59 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.