Wed·Dec 6, 2023Wednesday·December 6, 2023

1. 01*

   331 Models and Bilepton Searches at LHC

   Roberta Calabrese🇮🇹 · Alberto Orso Maria Iorio🇮🇹 · Stefano Morisi🇮🇹 · Giulia Ricciardi🇮🇹 · Natascia Vignaroli🇮🇹

   Despite being remarkable predictive, the Standard Model leaves unanswered several important issues, which motivate an ongoing search for its extensions. One fashionable possibility are the so-called 331 models, where the electroweak gauge group is extended to $S{U}_L(3)\times U(1)$. We focus on a minimal extension which includes vector-like quarks (VLQs) and new gauge bosons, performing a consistent analysis of the production at LHC of a pair of doubly-charged bileptons. We include for the first time all the relevant processes where VLQs contribute, and in particular the associate production VLQ-bilepton. Finally, we extract the bound on the bilepton mass, $m_Y>$ 1300 GeV, from a reinterpretation of a recent ATLAS search for doubly-charged Higgs bosons in multi-lepton final states.

   hep-phhep-exPRD(2024)·9 citations
2. 02*

   Hints of Entanglement Suppression in Hyperon-Nucleon Scattering

   Qiaofeng Liu🇺🇸 · Ian Low🇺🇸

   Hyperon ($Y=\Sigma ,\Lambda$)-nucleon ($N=n,p$) interactions are crucial for understanding the existence of neutron stars heavier than two solar masses. Amid renewed experimental efforts, we study $YN$ scatterings from the perspective of quantum information, focusing on whether spin entanglement is suppressed in the s-wave channel, which is observed in $np$ scattering and leads to enhanced global symmetries. Using global fits of phase shifts from experimental data, we find hints of entanglement suppression among the eight flavor channels in the strangeness $S=-1$ sector, similar to the $np$ case. One exception is the ${\Sigma }^{+}p$ channel, where conflicting global fits lead to inconclusive outcome. We then propose ''quantum'' observables in ${\Sigma }^{+}p$ scattering to help resolve the differing global fits.

   hep-phhep-exnucl-exnucl-th+1PLB(2024)·36 citations
3. 03*

   Prompt neutrinos from the atmosphere to the forward region of LHC

   Weidong Bai🇨🇳 · Milind Diwan🇺🇸 · Maria Vittoria Garzelli🇩🇪 · Yu Seon Jeong🇰🇷 · Mary Hall Reno🇺🇸

   We investigate the kinematical regions that are important for producing prompt neutrinos in the atmosphere and in the forward region of the LHC, as probed by different experiments. We illustrate the results as a function of the center-of-mass nucleon-nucleon collision energies and rapidities of neutrinos and of the parent heavy-flavoured hadrons. We find overlap in part of the kinematic space.

   hep-phastro-ph.HEPoS(2024)·0 citations
4. 04*

   Bubble wall velocities with an extended fluid Ansatz

   Glauber C. Dorsch🇧🇷 · Daniel A. Pinto🇧🇷

   We compute the terminal bubble wall velocity during a cosmological phase transition by modelling non-equilibrium effects in the plasma with the so-called "extended fluid Ansatz". A ${\varphi }^6$ operator is included in the Standard Model effective potential to mimic effects of new physics. Hydrodynamical heating of the plasma ahead of the bubble is taken into account. We find that the inclusion of higher order terms in the fluid Ansatz is typically relevant, and may even turn detonation solutions into deflagrations. Our results also corroborate recent findings in the literature that, for a Standard Model particle content in the plasma, only deflagration solutions are viable. However, we also show that this outcome may be altered in a theory with a different particle content.

   hep-phhep-thJCAP(2024)·27 citations
5. 05*

   Pole determination of $X(3960)$ and $X_0(4140)$ in decay $B^{+}\to K^{+}{D}_s^{+}{D}_s^{-}$

   Jialiang Lu🇨🇳 · Xuan Luo🇨🇳 · Mao Song🇨🇳 · Gang Li🇨🇳

   Two near-threshold peaking structures with spin-parities $J^{PC}=0^{++}$ were recently discovered by the LHCb Collaboration in the $D_s^{+}{D}_s^{-}$ invariant mass distribution of the decay process $B^{+}\to D_s^{+}{D}_s^{-}{K}^{+}$. In our study, we employed a coupled-channel model to fit the experimental results published by the LHCb collaboration, simultaneously fitting the model to the invariant mass distributions of $M_{D_s^{+}{D}_s^{-}}$, $M_{D_s^{+}{K}^{+}}$, and $M_{D_s^{-}{K}^{+}}$. We utilized a coupled-channel model to search for the poles of $X(3960)$ and $X_0(4140)$. The determination of the poles is meaningful in itself, and it also lays an foundation for the future research on $X(3960)$ and $X_0(4140)$. Upon turning off the coupled-channel and performing another fit, we observed a change in the fitting quality, the effect was almost entirely due to the peak of $X(3960)$, so we suggest that $X(3960)$ may not be a kinematic effect.

   hep-phhep-ex1 citation
6. 06*

   Pion axioproduction revisited

   Cheng-Cheng Li🇨🇳 · Tao-Ran Hu🇨🇳 · Feng-Kun Guo🇨🇳 · Ulf-G. Meißner🇩🇪

   In this work, we extend the analysis of the pion axioproduction, $aN\to \pi N$, to include the impact of the Roper resonance $N^{\ast }(1440)$ together the previously studied $\Delta (1232)$ resonance. Our theoretical framework is chiral perturbation theory with explicit resonance fields to account for their respective impacts. We find that the Roper resonance also leads to an enhancement of the cross section within its energy range for various axion models.

   hep-phhep-exPRD(2024)·6 citations
7. 07*

   Shedding light on charmonium

   Zhiguo Wang🇨🇳 · Meijian Li🇪🇸 · Yang Li🇨🇳 · James P. Vary🇺🇸

   We investigate E1 radiative transitions within charmonium in a relativistic approach based on light-front QCD. In quantum field theory, two sets of processes are pure E1: ${\chi }_{c0}\to J/\psi \gamma$ ($\psi \to {\chi }_{c0}\gamma$) and $h_c\to {\eta }_c\gamma$ (${\eta }_c^{\prime }\to h_c\gamma$), both involving the $P$-wave charmonia. We compute the E1 radiative decay widths as well as the corresponding transition form factors of various processes including those involving $2P$ states. These observables provide an access to the microscopic structures of the $P$-wave charmonium. We show that our parameter-free predictions are in excellent agreement with the experimental measurements as well as lattice simulations whenever available.

   hep-phnucl-thPRD(2024)·7 citations
8. 08*

   Induced color charges in QGP at Polyakov's loop and chromomagnetic fields

   V. Skalozub🇺🇦 · I. Gamolsky🇺🇦

   In quark-gluon plasma (QGP), at high temperature the spontaneous generation of color magnetic fields, H^3(T), H^8(T) and usual magnetic field $H(T)isrealized.Also,classicalfield-A_0(T)condensatedirectlyrelatedtothePolyakovloop-isspontaneouslycreated.ThecommongenerationofbothofthemwithinthetwoloopeffectivepotentialwasinvestigatedrecentlyforSU(2)gluodynamics.Thevaluesofthefieldstrengthsandthemechanismofthemagneticfieldsstabilizationdueto{A}_0(T)havebeendiscovered.Inthepresentpaper,wedevelopfurthertheseinvestigationsinordertofindneweffectsofQGP.Firstofall,wegeneralizetheSU(2)considerationtothefullQCDcase.Thenwecalculatetheinducedcolorcharge{Q}_{(}ind{)}^{3}atthebackgroundmagneticfieldH(T)andthecondensates{A}_0^3(T).Thefield$ A_0^8(T) is zero in used two-loop approximation. So, Q_{ind}^8 is zero also. We conclude that magnetic field essentially influences the induced charge compared to the zero field case investigated in \cite{skal21-cond-156}. The extension to other type magnetic fields is given. Key words: spontaneous magnetization, high temperature, asymptotic freedom, effective potential, $A_0$ condensate, effective charge, effective vertexes.

   hep-ph0 citations
9. 09*

   SKA Sensitivity to Sub-GeV Dark Matter Decay: Synchrotron Radio Emissions in White Dwarf Magnetospheres

   Kenji Kadota🇨🇳 · Shota Kisaka🇯🇵

   We investigate the potential of the Square Kilometre Array (SKA) in detecting synchrotron radiation emitted from the decay of sub-GeV dark matter (dark matter with masses below the GeV scale) in the presence of strong magnetic fields. As a concrete setup, we consider scenarios where the magnetosphere of a magnetic white dwarf overlaps with dense dark matter environments, such as those surrounding a primordial black hole. Our study reveals that the encounters of compact objects such as white dwarfs and black holes offer a promising avenue for upcoming radio telescopes to probe the properties of light dark matter, which has been less explored compared with more conventional heavier (masses above the GeV scale) dark matter.

   hep-phastro-ph.COastro-ph.HEPRD(2024)·0 citations
10. 10*

    The anomalous Lagrangian in ChPT at NNLO

    Johan Bijnens🇸🇪 · Nils Hermansson-Truedsson🇸🇪 · Joan Ruiz-Vidal🇸🇪

    The anomalous Lagrangian in mesonic Chiral Perturbation Theory, of odd intrinsic parity, is determined to next-to-next-to-leading order thereby completing the order $p^8$ Lagrangian. A schematic view of its construction with the MINIBAR package for Mathematica is presented and the final operator count is discussed for a general number of light quark flavours as well as for the physical cases $N_f=2,3$. The number of operators in our explicit construction of the Lagrangian basis is consistent with the number derived using the Hilbert series in the literature.

    hep-phhep-thPoS(2024)·0 citations
11. 11*

    Hadronization and Decay of Excited Heavy Hadrons in Herwig 7

    M.R. Masouminia🇬🇧 · P. Richardson🇬🇧

    We revisit the hadronization and decay of excited heavy mesons and heavy baryons in Herwig 7 general-purpose event-generator, following four distinct steps: (i) Passing through the polarization of heavy hadrons at the end of parton shower through the application of heavy quark effective theory (HQET), where the emergence of a spin-flavour symmetry allows for the determination of the polarizations of the excited heavy mesons and heavy baryons from the helicity states of the light and heavy quarks. (ii) Improving the strong and radiative decay modes of the excited heavy mesons, where in the absence of conclusive experimental data on many of the decays, one needs to rely on HQET symmetries to determine the favoured decay modes, widths and branching ratios. (iii) Re-examination of the production rates of heavy hadrons using all available experimental data sources and (iv) performing a general tune for Herwig's free parameters to reflect the implemented changes. We compare our predictions against existing experimental data in the presence/absence of the newly implemented updates. These improvements will be available with Herwig-7.3.0 public release.

    hep-phJHEP(2024)·14 citations
12. 12*

    Hidden-bottom hadronic transitions of ${\rm Y}(10753)$

    Shidong Liu🇨🇳 · Zuxin Cai🇨🇳 · Zhaosai Jia🇨🇳 · Gang Li🇨🇳 · Jujun Xie🇨🇳

    Assuming that the ${\rm Y}(10753)$ is a $4S$-$3D$ mixed state, we investigated the hidden-bottom hadronic decays of the ${\rm Y}(10753)\to {\eta }_b(1S)\omega ({\eta }^{(\prime )})$ via the intermediate meson loops. In a commonly accepted range of the model parameter $\alpha$ in the form factor, the predicted branching ratios may reach to the order of $10^{-3}$--$10^{-2}$. The relative ratio of the partial decay widths of the ${\rm Y}(10753)\to {\eta }_b{\eta }^{(\prime )}$ to ${\rm Y}(10753)\to {\eta }_b\omega$ is found to be dependent on the $\eta$-${\eta }^{\prime }$ mixing angle. In addition, we also calculated the ratios of the partial decays widths of the ${\rm Y}(10753)\to {\eta }_b\omega$ to ${\rm Y}(10753)\to {\rm Y}(nS){\pi }^{+}{\pi }^{-}$ ($n=1,2$), which are found to be around 0.4 and 0.2 for $n=1$ and $n=2$, respectively. These values are in accordance with the preliminary experimental results. The calculations presented here tend to favor the ${\rm Y}(10753)$ as the $4S$-$3D$ mixture. We hope these predictions could be verified by the future BelleII experiments.

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

    QCD sum rule studies on the possible double-peak structure of the $X17$ particle

    Hua-Xing Chen🇨🇳

    The $X17$ particle, discovered by Krasznahorkay et al. at ATOMKI, was recently confirmed in the $\gamma \gamma$ invariant mass spectra by Abraamyan et al. at JINR. We notice with surprise and interest that the $X17$ seems to have a double-peak structure. This is in a possible coincidence with our QCD sum rule study of [arXiv:2006.01018], where we interpreted the $X17$ as a tetraquark state composed of four bare quarks ($u\bar{u}d\bar{d}$), and claimed that ``A unique feature of this tetraquark assignment is that we predict two almost degenerate states with significantly different widths''. These two different tetraquark states are described by two different chiral tetraquark currents ${\bar{u}}_L{\gamma }_{\mu }{d}_L{\bar{d}}_L{\gamma }^{\mu }{u}_L$ and ${\bar{u}}_L{\gamma }_{\mu }{d}_L{\bar{d}}_R{\gamma }^{\mu }{u}_R$. To verify whether the tetraquark assignment is correct or not, we replace the up and down quarks by the strange quarks, and apply the QCD sum rule method to study the other four chiral tetraquark currents ${\bar{u}}_L{\gamma }_{\mu }{s}_L{\bar{s}}_L{\gamma }^{\mu }{u}_L$, ${\bar{u}}_L{\gamma }_{\mu }{s}_L{\bar{s}}_R{\gamma }^{\mu }{u}_R$, ${\bar{d}}_L{\gamma }_{\mu }{s}_L{\bar{s}}_L{\gamma }^{\mu }{d}_L$, and ${\bar{d}}_L{\gamma }_{\mu }{s}_L{\bar{s}}_R{\gamma }^{\mu }{d}_R$. We calculate their correlation functions, and find that non-perturbative QCD effects do not contribute much to them. Our results suggest that there may exist four almost degenerate tetraquark states with masses about $236\sim 296$ MeV. Each of these states is composed of four bare quarks, either $u\bar{u}s\bar{s}$ or $d\bar{d}s\bar{s}$.

    hep-phMod.Phys.Lett.A(2024)·2 citations
14. 14*

    Radiative corrections of the order $\mathcal{O}({\alpha }^3{L}^3)$ to unpolarized muon decay spectrum

    U.E. Voznaya🇷🇺 · A.B.Arbuzov🇷🇺

    Calculation of higher-order radiative corrections to unpolarized muon decay spectrum is discussed. Results for the orders $\mathcal{O}({\alpha }^{2}L)$, $\mathcal{O}({\alpha }^3{L}^3)$ and $\mathcal{O}({\alpha }^3{L}^2)$ are presented.

    hep-ph1 citation
15. 15*

    Two Texture Zeros for Dirac Neutrinos in a Diagonal charged Lepton basis

    Yessica Lenis🇨🇴 · John D. Gómez🇨🇴 · William A. Ponce🇨🇴 · Richard H. Benavides🇨🇴

    A systematic study of the neutrino mass matrix $M_{\nu }$ with two texture zeros in a basis where the charged leptons are diagonal, and under the assumption that neutrinos are Dirac particles, is carried through in detail. Our study is done without any approximation, first analytically and then numerically. Current neutrino oscillation data are used in our analysis. Phenomenological implications of $M_{\nu }$ on the lepton CP violation and neutrino mass spectrum are explored.

    hep-phCPC(2025)·3 citations
16. 16*

    A new subtraction scheme at NLO exploiting the privilege of kT-factorization

    Alessandro Giachino🇵🇱 · Andreas van Hameren🇵🇱 · Grzegorz Ziarko🇵🇱

    We present a subtraction method for the calculation of real-radiation integrals at NLO in hybrid kT-factorization. The main difference with existing methods for collinear factorization is that we subtract the momentum recoil, occurring due to the mapping from an (n+1)-particle phase space to an n-particle phase space, from the initial-state momenta, instead of distributing it over the final-state momenta.

    hep-phJHEP(2024)·7 citations
17. 17*

    On the Photon-Fermion Vertex

    Orlando Oliveira🇵🇹

    The QED Dyson-Schwinger equation for the photon-fermion one-particle irreducible Green function, the photon-fermion vertex, is investigated using a Ball-Chiu description for its longitudinal part, together with the Kızılersu-Reenders-Pennington basis for its transverse part. Exact expressions for all the transverse form factors are derived from the vertex Dyson-Schwinger equation. Furthermore, feeding the Dyson-Schwinger equation with a simplified vertex that goes beyond the perturbative solution, some of the results of the one-loop perturbative calculation are recovered in a more general framework. The approach allows also exact results for the on-shell vertex, that encode the anomalous magnetic and electric fermion couplings, and for its soft photon limit. The investigation of the chiral limit of the photon-fermion vertex shows that a limited number of transverse form factors are required, a result that, once more, is in good agreement with a one-loop calculation for QED but that appears in a more general framework. The results derived for the photon-fermion vertex can be extended easily to the quark-gluon vertex after proper modifications.

    hep-phhep-th0 citations
18. 18*

    Resonant Spin-Flavor Precession of Sterile Neutrinos

    Edward Wang🇩🇪

    We analyze the impact of resonant conversions mediated by non-vanishing magnetic moments between active neutrinos and a heavy sterile neutrino on the supernova neutrino flux. We present the level-crossing scheme for such a scenario and derive the neutrino fluxes after conversion, paying particular attention to the order in which the resonances occur. We then compute the expected event rates from the neutronization burst of a future supernova at DUNE and Hyper-Kamiokande to derive new constraints on the neutrino magnetic moment. With this, we find a sensitivity down to a few $10^{-15}{\mu }_B$ for a sterile neutrino in the $O(\mathrm{eV})$ mass range.

    hep-phastro-ph.HEhep-exJCAP(2024)·3 citations
19. 19*

    Semi-visible jets, energy-based models, and self-supervision

    Luigi Favaro🇩🇪 · Michael Krämer🇩🇪 · Tanmoy Modak🇩🇪 · Tilman Plehn🇩🇪 · Jan Rüschkamp🇩🇪

    We present DarkCLR, a novel framework for detecting semi-visible jets at the LHC. DarkCLR uses a self-supervised contrastive-learning approach to create observables that are approximately invariant under relevant transformations. We use background-enhanced data to create a sensitive representation and evaluate the representations using a CLR-inspired anomaly score and a normalized autoencoder as density estimators. Our results show a remarkable sensitivity for a wide range of semi-visible jets and are more robust than a supervised classifier trained on a specific signal.

    hep-phSciPost Phys.(2025)·19 citations
20. 20*

    Post-Newtonian Binary Dynamics in Effective Field Theory of Horndeski Gravity

    Wen-Hao Wu🇨🇳 · Yong Tang🇨🇳

    General relativity has been very successful since its proposal more a century ago. However, various cosmological observations and theoretical consistency still motivate us to explore extended gravity theories. Horndeski gravity stands out as one attractive theory by introducing only one scalar field. Here we formulate the post-Newtonian effective field theory of Horndeski gravity and investigate the conservative dynamics of the inspiral compact binary systems. We calculate the leading effective Lagrangian for a compact binary and obtain the periastron advance per period. In particular, we apply our analytical calculation to two binary systems, PSR B 1534+12 and PSR J0737-3039, and constrain the relevant model parameters. The theoretical framework can also be extended to higher order systematically.

    ↳ gr-qcastro-ph.COhep-phCPC(2024)·5 citations
21. 21*

    Stress inside the pion in holographic light-front QCD

    Yang Li🇨🇳 · James P. Vary🇺🇸

    In this work, we propose a method to compute the gravitational form factor $D(Q^2)$ in holographic QCD by exploiting the remarkable correspondence between semi-classical light-front QCD and semi-classical field theories in wrapped spacetime in 5D. The use of light-front holography bridges physics at large $Q^2$ as attained in light-front QCD and physics at small $Q^2$ where the coupling to scalar and tensor fields, i.e. glueballs, are dominant. As an application, we compute the $D$-term for the pion, and compare the results with recent lattice simulations.

    ↳ hep-thhep-phnucl-thPRD(2024)·25 citations
22. 22*

    Gluon condensation: from nucleon to Galactic center

    Wei Zhu🇨🇳 · Zi-Qing Xia🇨🇳 · Yu-Chen Tang🇨🇳 · Lei Feng🇨🇳

    The Galactic Center Excess (GCE), one of the most remarkable discoveries by Fermi-LAT, has prompted extensive exploration over the past decade, often attributed to dark matter or millisecond pulsars. This work proposes a novel interpretation on the origin of the GCE, focusing on the observed spectral shape. Protons are accelerated at the Galactic center and collide with the neutron cluster on the surface of the non-rotating neutron stars. Due to the gluon condensation in nucleons, these collisions produce a large number of mesons, which have reached to the saturation state and subsequently generate the broken power law in the gamma ray spectra. We explained the spectral shape of GCE using the gluon condensation and an assumption of existing the non-rotating neutron stars at the Galactic center. This example of the gluon condensation mechanism not only expands the applications of the hadronic scenario in the cosmic gamma ray spectra but also provides a new evidence of the gluon condensation.

    ↳ astro-ph.HEhep-phPRD(2023)·2 citations
23. 23*

    First-order event plane correlated directed and triangular flow from fixed-target energies at RHIC-STAR

    Sharang Rav Sharma🇮🇳

    We report the measurement of first-order event plane correlated directed flow $(v_1)$ and triangular flow $v_3$ for identified hadrons (${\pi }^{\pm }$, $K^{\pm }$, and $p$), net-particle (net-K, net-p), and light nuclei ($d$ and $t$) in Au+Au collisions at $\sqrt{s_{\text{NN}}}$ = 3.2, 3.5, and 3.9 GeV in fixed-target mode from the second phase of beam energy scan (BES-II) program at RHIC-STAR. The $v_1$ slopes at mid-rapidity for identified hadrons and net-particles except ${\pi }^{+}$ are found to be positive, implying the effect of dominant repulsive baryonic interactions. The slope of $v_1$ for net-kaon undergoes a sign change from negative to positive at a lower collision energy compared to net-proton. An approximate atomic mass number scaling is observed in the measured $v_1$ slopes of light nuclei at mid-rapidity, which favours the nucleon coalescence mechanism for the production of light nuclei. The $v_3$ slope for all particles decreases in magnitude with increasing collision energy, suggesting a notable integrated impact of the mean-field, baryon stopping, and collision geometry at lower collision energies.

    ↳ nucl-exhep-exhep-phUniverse(2024)·1 citation
24. 24*

    Conserved energy-momentum tensor for real-time lattice simulations

    Kirill Boguslavski🇦🇹 · Tuomas Lappi🇫🇮 · Jarkko Peuron🇫🇮 · Pragya Singh🇫🇮

    We derive an expression for the energy-momentum tensor in the discrete lattice formulation of pure glue QCD. The resulting expression satisfies the continuity equation for energy conservation up to numerical errors with a symmetric procedure for the time discretization. In the case of the momentum conservation equation, we obtain an expression that is of higher accuracy in lattice spacing ($\mathcal{O}(a^2)$) than the naive discretization where fields in the continuum expressions are replaced by discretized counterparts. The improvements are verified by performing numerical tests on the derived expressions using classical real-time lattice gauge theory simulations. We demonstrate substantial reductions in relative error of one to several orders of magnitude compared to a naive discretization for both energy and momentum conservation equations. We expect our formulation to have applications in the area of pre-equilibrium dynamics in ultrarelativistic heavy ion collisions, in particular for the extraction of transport coefficients such as shear viscosity.

    ↳ nucl-thhep-lathep-phEPJC(2024)·1 citation
25. 25*

    Observable imprints of primordial gravitational waves on the temperature anisotropies of the Cosmic Microwave Background

    Miguel-Angel Sanchis-Lozano🇪🇸 · Veronica Sanz🇪🇸

    We examine the contribution of tensor modes, in addition to the dominant scalar ones, on the temperature anisotropies of the cosmic microwave background (CMB). To this end, we analyze in detail the temperature two-point angular correlation function $C(\theta )$ from the Planck 2018 dataset, focusing on large angles ($\theta \gtrsim 120^{\circ }$) corresponding to small $\ell$ multipoles. A hierarchical set of infrared cutoffs are naturally introduced to the scalar and tensor power spectra of the CMB by invoking an extra Kaluza-Klein dimension compactifying at about the GUT scale between the Planck epoch and the start of inflation. We associate this set of lower scalar and tensor cutoffs with the parity of the multipole expansion of the $C(\theta )$ function. By fitting the Planck 2018 data we compute the multipole coefficients thereby reproducing the well-known odd-parity preference in angular correlations seen by all three satellite missions COBE, WMAP and Planck. Our fits improve significantly once tensor modes are included in the analysis, hence providing a hint of the imprints of primordial gravitational waves on the temperature correlations observed in the CMB today. To conclude we suggest a relationship between, on the one hand, the lack of (positive) large-angle correlations and the odd-parity dominance in the CMB and, on the other hand, the effect of primordial gravitational waves on the CMB temperature anisotropies.

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

    Madgraph5_aMC@NLO on GPUs and vector CPUs Experience with the first alpha release

    Stephan Hageboeck🇨🇭 · Taylor Childers🇺🇸 · Walter Hopkins🇺🇸 · Olivier Mattelaer🇧🇪 · Nathan Nichols🇺🇸 · Stefan Roiser🇨🇭 · Jørgen Teig🇨🇭 · Andrea Valassi🇨🇭 · Carl Vuosalo🇺🇸 · Zenny Wettersten🇨🇭

    Madgraph5_aMC@NLO is one of the most-frequently used Monte-Carlo event generators at the LHC, and an important consumer of compute resources. The software has been reengineered to maintain the overall look and feel of the user interface while speeding up event generation on CPUs and GPUs. The most computationally intensive part, the calculation of "matrix elements", is offloaded to new implementations optimised for GPUs and for CPU vector instructions, using event-level data parallelism. We present the work to support accelerated leading-order QCD processes, and discuss how this work is going to be released to Madgraph5_aMC@NLO's users.

    ↳ physics.comp-phhep-phEPJ Web Conf.(2024)·22 citations
27. 27*

    Shallow Bound States and Hints for Broad Resonances with Quark Content $\bar{b}\bar{c}ud$ in $B$-$\bar{D}$ and $B^{\ast }$-$\bar{D}$ Scattering from Lattice QCD

    Constantia Alexandrou🇨🇾 · Jacob Finkenrath🇩🇪 · Theodoros Leontiou🇨🇾 · Stefan Meinel🇺🇸 · Martin Pflaumer🇩🇪 · Marc Wagner🇩🇪

    We present the first determination of the energy dependence of the $B$-$\bar{D}$ and $B^{\ast }$-$\bar{D}$ isospin-0, $S$-wave scattering amplitudes both below and above the thresholds using lattice QCD, which allows us to investigate rigorously whether mixed bottom-charm $\bar{b}\bar{c}ud$ tetraquarks exist as bound states or resonances. The scattering phase shifts are obtained using Lüscher's method from the energy spectra in two different volumes. To ensure that no relevant energy level is missed, we use large, symmetric $7\times 7$ and $8\times 8$ correlation matrices that include, at both source and sink, $B^{(\ast )}$-$\bar{D}$ scattering operators with the lowest three or four possible back-to-back momenta in addition to local $\bar{b}\bar{c}ud$ operators. We fit the energy dependence of the extracted scattering phase shifts using effective-range expansions. We observe sharp peaks in the $B^{(\ast )}$-$\bar{D}$ scattering rates close to the thresholds, which are associated with shallow bound states, either genuine or virtual, a few MeV or less below the $B^{(\ast )}$-$\bar{D}$ thresholds. In addition, we find hints for resonances with masses of order $100$ MeV above the thresholds and decay widths of order $200$ MeV.

    ↳ hep-lathep-exhep-phnucl-thPRL(2024)·36 citations
28. 28*

    The Chiral Separation Effect from lattice QCD at the physical point

    Bastian B. Brandt🇩🇪 · Gergely Endrődi🇩🇪 · Eduardo Garnacho-Velasco🇩🇪 · Gergely Markó🇩🇪

    In this paper we study the Chiral Separation Effect by means of first-principles lattice QCD simulations. For the first time in the literature, we determine the continuum limit of the associated conductivity using 2+1 flavors of dynamical staggered quarks at physical masses. The results reveal a suppression of the conductivity in the confined phase and a gradual enhancement toward the perturbative value for high temperatures. In addition to our dynamical setup, we also investigate the impact of the quenched approximation on the conductivity, using both staggered and Wilson quarks. Finally, we highlight the relevance of employing conserved vector and anomalous axial currents in the lattice simulations.

    ↳ hep-lathep-phhep-thnucl-thJHEP(2024)·16 citations
29. 29*

    Improving Constraints on Inflation with CMB Delensing

    Cynthia Trendafilova🇺🇸 · Selim C. Hotinli🇺🇸 · Joel Meyers🇺🇸

    The delensing of cosmic microwave background (CMB) maps will be increasingly valuable for extracting as much information as possible from future CMB surveys. Delensing provides many general benefits, including sharpening of the acoustic peaks, more accurate recovery of the damping tail, and reduction of lensing-induced $B$-mode power. In this paper we present several applications of delensing focused on testing theories of early-universe inflation with observations of the CMB. We find that delensing the CMB results in improved parameter constraints for reconstructing the spectrum of primordial curvature fluctuations, probing oscillatory features in the primordial curvature spectrum, measuring the spatial curvature of the universe, and constraining several different models of isocurvature perturbations. In some cases we find that delensing can recover almost all of the constraining power contained in unlensed spectra, and it will be a particularly valuable analysis technique to achieve further improvements in constraints for model parameters whose measurements are not expected to improve significantly when utilizing only lensed CMB maps from next-generation CMB surveys. We also quantify the prospects of testing the single-field inflation tensor consistency condition using delensed CMB data; we find it to be out of reach of current and proposed experimental technology and advocate for alternative detection methods.

    ↳ astro-ph.COgr-qchep-phJCAP(2024)·13 citations
30. 30*

    PROSPECT: A profile likelihood code for frequentist cosmological parameter inference

    Emil Brinch Holm🇩🇰 · Andreas Nygaard🇩🇰 · Jeppe Dakin🇨🇭 · Steen Hannestad🇩🇰 · Thomas Tram🇩🇰

    Cosmological parameter inference has been dominated by the Bayesian approach for the past two decades, primarily due to its computational efficiency. However, the Bayesian approach involves integration of the posterior probability and therefore depends on both the choice of model parametrisation and the choice of prior on the model parameter space. In some cases, this can lead to conclusions which are driven by choice of parametrisation and priors rather than by data. The profile likelihood method provides a complementary frequentist tool which can be used to investigate this effect. In this paper, we present the code PROSPECT for computing profile likelihoods in cosmology. We showcase the code using a phenomenological model for converting dark matter into dark radiation that suffers from large volume effects and prior dependence. PROSPECT is compatible with both cobaya and MontePython, and is publicly available at https://github.com/AarhusCosmology/prospect_public.

    ↳ astro-ph.COastro-ph.IMhep-phMNRAS(2024)·31 citations
31. 31*

    Real-time correlators in 3+1D thermal lattice gauge theory

    Kirill Boguslavski🇦🇹 · Paul Hotzy🇦🇹 · David I. Müller🇦🇹

    We present the first direct ab-initio computation of unequal-time correlation functions in non-Abelian lattice gauge theory. We demonstrate non-trivial consistency relations among correlators, time-translation invariance, and agreement with Monte-Carlo results for thermal equilibrium in 3+1 dimensions by employing our stabilized complex Langevin method. Our work sets the stage to extract real-time observables, relevant to quark-gluon plasma physics within a first-principles real-time framework.

    ↳ hep-latcond-mat.otherhep-phhep-th+1PRD(2024)·17 citations
32. 32*

    Dissecting the Stochastic Gravitational Wave Background with Astrometry

    Mesut Çalışkan🇺🇸 · Yifan Chen🇩🇰 · Liang Dai🇺🇸 · Neha Anil Kumar🇺🇸 · Isak Stomberg🇩🇪 · Xiao Xue🇩🇪

    Astrometry, the precise measurement of star motions, offers an alternative avenue to investigate low-frequency gravitational waves through the spatial deflection of photons, complementing pulsar timing arrays reliant on timing residuals. Upcoming data from Gaia and Roman can not only cross-check pulsar timing array findings but also explore the uncharted frequency range bridging pulsar timing arrays and LISA. We present an analytical framework to evaluate the feasibility of detecting a gravitational wave background, considering measurement noise and the intrinsic variability of the stochastic background. Furthermore, we highlight astrometry's crucial role in uncovering key properties of the gravitational wave background, such as spectral index and chirality, employing information-matrix analysis. Finally, we simulate the emergence of quadrupolar correlations, commonly referred to as the generalized Hellings-Downs curves.

    ↳ gr-qcastro-ph.COastro-ph.HEastro-ph.IM+1JCAP(2024)·36 citations
33. 33*

    Phenomenology of Spillway Preheating: Equation of State and Gravitational Waves

    Gareth Mansfield🇺🇸 · JiJi Fan🇺🇸 · Qianshu Lu🇺🇸

    In the canonical tachyonic resonance preheating scenario, only an order one fraction of energy density in the inflaton is transferred to radiation, due to backreaction effects. One possible way to improve the energy transfer efficiency is to allow for the perturbative decays of the resonantly produced daughter particles, which serve as the "spillway" to drain the direct decay products from inflaton and to reduce the backreaction. In this article, we study two observational consequences of spillway preheating. The first is on the inflationary observables: the scalar spectrum tilt $n_s$ and tensor-to-scalar ratio $r$. The spillway scenario modifies the evolution of the equation of state between the end of inflation and the thermal big bang. As a result, it affects the time elapsed from inflation to the Cosmic Microwave Background (CMB), as well as the fits of inflationary models and their corresponding prediction for $n_s$ and $r$. We map out the equation of state by systematically scanning the parameter space of the spillway scenario, and show that the most efficient spillway scenario predicts a bluer spectrum, compared to the tachyonic preheating scenario. Another consequence is the production of high-frequency gravitational waves (GWs). Comparing the simulation results with those of tachyonic preheating, we find that the existence of spillways leads to sharper-peaked GW spectra with a mildly damped amplitude.

    ↳ astro-ph.COhep-phPRD(2024)·12 citations
34. 34*

    Supramassive dark objects with neutron star origin

    M. Vikiaris🇬🇷 · V. Petousis🇨🇿 · M. Veselsky🇨🇿 · Ch.C. Moustakidis🇬🇷

    Till today, the nature of Dark Matter (DM) remains elusive despite all our efforts. This missing matter of the universe has not been observed by the already operating DM direct-detection experiments, but we can infer its gravitational effects. Galaxies and clusters of galaxies are most likely to contain DM trapped to their gravitational field. This leads us to the natural assumption that compact objects might contain DM too. Among the compact objects exist in galaxies, neutron stars are considered as natural laboratories, where theories can be tested, and observational data can be received. Thus, many models of DM have proposed it's presence in those stars. In particular, in the present study we focus on two types of dark matter particles, namely fermions and bosons with a mass range of [0.01-1.5] GeV and self-interaction strength in the range [10${}^{-4}$-10${}^{-1}$] MeV${}^{-1}$. By employing the two-fluid model, we discovered a stable area in the M-R diagram of a celestial formation consisting of neutron star matter and DM that is substantial in size. This formation spans hundreds of kilometers in diameter and possesses a mass equivalent to 100 or more times the Solar mass. To elucidate, this entity resembles an enormous celestial body of DM, with a neutron star at its core. This implies that a supramassive stellar compact entity can exist without encountering any issues of stability and without undergoing a collapse into a black hole. In any case, the present theoretical prediction can, if combined with corresponding observations, shed light on the existence of DM and even more on its basic properties.

    ↳ astro-ph.HEastro-ph.COastro-ph.GAgr-qc+2PRD(2024)·12 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.