Tue·Oct 31, 2023Tuesday·October 31, 2023

1. 01*

   Entanglement entropy of proton and its relation to thermodynamics entropy

   Krzysztof Kutak🇵🇱

   I discuss the thermodynamics-based derivation of the formula for the entanglement entropy of a system of gluons. The derivation is based on an approach where saturation and the Unruh effect were used to obtain and discuss the entropy of gluons. The formula agrees, in the high-energy limit, up to a numerical factor, with more recent results, where arguments based on the density matrix and bipartition of the proton were used to obtain the formula. I also discuss the relation of entropy as obtained in BFKL in DLL approximation and with the application of the BK equation.

   hep-phhep-thquant-phProceedings of Epiphany 2024 Conference·12 citations
2. 02*

   NNLO Matrix-Element Corrections in VINCIA

   Peter Skands🇦🇺 · Christian T. Preuss🇩🇪

   We report on a new formalism for parton showers whose fixed-order expansion can be corrected through next-to-next-to-leading order (NNLO) in QCD. It is the first such formalism we are aware of that has no dependence on any auxiliary scales or external resummations and which is fully differential in all of the relevant phase spaces. Since the shower acts as the phase-space generator, the dominant singularity structures are encoded by construction and the method can generate unweighted events with very high efficiency without any significant initialisation time. We argue that the the method should be capable of achieving (at least) NNLO+NNDL accuracy for the shower evolution variable and use hadronic Z decays as a specific example.

   hep-phPoS(2024)·1 citation
3. 03*

   Resolved Photons in Sherpa

   Stefan Hoeche🇺🇸 · Frank Krauss🇬🇧 · Peter Meinzinger🇬🇧

   We present the first complete simulation framework, in the Sherpa event generator, for resolved photon interactions at next-to leading order accuracy. It includes photon spectra obtained through the equivalent-photon approximation, parton distribution functions to parametrize the hadronic structure of quasi-real photons, the matching of the parton shower to next-to leading order QCD calculations for resolved photon cross sections, and the modelling of multiple-parton interactions. We validate our framework against a wide range of photo-production data from LEP and HERA experiments, observing good overall agreement. We identify important future steps relevant for high-quality simulations at the planned Electron-Ion Collider.

   hep-phEPJC(2024)·13 citations
4. 04*

   Implications of the helicity conservation for on-shell and off-shell chirality production

   Kenji Fukushima🇯🇵 · Chengpeng Yu🇯🇵

   We analyze the helicity conservation following from the axial Ward identity for the massless fermion. We discuss the pair production of a fermion, $\ell$, and an anti-fermion, $\bar{\ell }$, from the annihilation process of photons, $\gamma$'s and conclude that the chirality production is prohibited in any annihilation process of on-shell $\gamma$'s. We demonstrate this selection rule in the tree-level process of $\gamma +\gamma \to \ell +\bar{\ell }$. We next consider the off-shell effect on the chirality production in the presence of the background magnetic field. We point out that the particle conversion process under the magnetic field induces the polarization of an incident $\gamma$, which can also be interpreted intuitively from the helicity conservation.

   hep-phphysics.optics1 citation
5. 05*

   Interaction of exotic states in a hadronic medium: the $Z_c(3900)$ case

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

   We investigate the interactions of the charged exotic state $Z_c(3900)$ in a hadronic medium composed of light mesons. We study processes such as $Z_c\pi \to D\bar{D}$, $Z_c\pi \to D^{\ast }{\bar{D}}^{\ast }$, $Z_c\pi \to D{\bar{D}}^{\ast }$ and the inverse ones. Using effective Lagrangians and form factors calculated with QCD sum rules (treating the $Z_c(3900)$ as a tetraquark) we estimate the vacuum and thermally-averaged cross-sections of these reactions. We find that the $Z_c(3900)$ has relatively large interaction cross sections with the constituent particles of the hadronic medium. After that, we use the production and suppression cross sections in a rate equation to estimate the time evolution of the $Z_c$ multiplicity. We include the $Z_c$ decay and regeneration terms. The coalescence model is employed to compute the initial $Z_c$ multiplicity for the compact tetraquark configuration. Our results indicate that the combined effects of hadronic interactions, hydrodynamical expansion, decay and regeneration affect the final yield, which is bigger than the initial value. Besides, the dependence of the $Z_c$ final yield with the centrality, center-of-mass energy and the charged hadron multiplicity measured at midrapidity $[d{N}_{ch}/d\eta (\eta <0.5)]$ is also investigated.

   hep-phJ.Phys.G(2024)·5 citations
6. 06*

   New bounds and future prospects for axion force searches at Penning trap experiments

   Xing Fan🇺🇸 · Mario Reig🇬🇧

   In this note we consider Penning trap experiments as probes of axion-mediated forces. We show that the current measurement of electron's $g$-factor already sets a new exclusion limit for monopole-dipole axion forces acting on the electron spin. We also show that the Penning trap's capability of switching an electron and a positron can isolate the effect of an axion force and suppress systematic effects.

   hep-phhep-exphysics.atom-ph9 citations
7. 07*

   On the Fractional Quark-Antiquark Confinement and Symplectic Quantum Mechanics

   M. Abu-Shady🇪🇬 · R. R. Luz🇧🇷 · G. X. A. Petronilo🇧🇷 · A. E. Santana🇧🇷 · R. G. G. Amorim🇧🇷

   Using the formalism of generalized fractional derivatives, a two-dimensional non-relativistic meson system is studied. The mesons are interacting by a Cornell potential. The system is formulated in the domain of the symplectic quantum mechanics by means of the generalized fractional Nikiforov-Uvarov method. The corresponding Wigner function and the energy eigenvalues are then derived. The effect of fractional parameters $\alpha$ and $\beta$ with the ground state solution is analyzed through the Wigner function for the charm-anticharm, bottom-antibottom and $b\overline{c}$ mesons. One of the fundamental achievements of such Cornell model is the determination of heavy quarkonia mass spectra. We have computed these masses and the

   hep-phnucl-thInt.J.Mod.Phys.A(2024)·3 citations
8. 08*

   Abundant radiation of soft photons: a puzzle lasting four decades

   Boris Kopeliovich🇨🇱 · Irina Potashnikova🇨🇱 · Ivan Schmidt🇨🇱

   The observed enhancement of low-kT photons in comparison with incorrect calculations, should not be treated as a puzzle. The paper by Low considered a large rapidity gap process of diffractive excitation of a hadron, h -> h+\gamma, rather than multiple hadron production spanning all over the rapidity interval between colliding hadrons. The optical theorem connects these two processes, and what is inner bremsstrahlung, suppressed according to Low, corresponds to radiation from final state hadrons. Thus, the main result of the Low theorem, based on gauge invariance of the diffractive bremsstrahlung amplitude, supplemented with the optical theorem, contradicts the so-called bremsstrahlung model. The latter has been used for comparison with data, leading to the longstanding soft photon puzzle.

   hep-phPoS(2024)·0 citations
9. 09*

   Probing Parity Manifest Minimal Left-Right Symmetric Model through $CP$ Violation & Anomalous Magnetic Moment of Charged Leptons Constrained by Lepton Flavor Violating $l_i\to l_j\gamma$ & $l_i\to 3l_j$ Channels

   Rafid Buksh🇧🇩 · Samim Ul Islam🇧🇩

   While the Standard Model remains the prevailing description of natural phenomena, several observed phenomena continue to elude its explanation. To address these challenges, we investigate the Minimal Left-Right Symmetric Model, an immediate extension of the Standard Model. This model adeptly resolves issues related to parity violation and neutrino mass smallness by incorporating the seesaw mechanism. Our investigation focuses on assessing the Parity Manifest Minimal Left-Right Symmetric Model's contributions to specific phenomena, namely the anomalous magnetic moment (AMM) and CP violation of charged leptons. First, the model's coupling parameter space is derived from the experimental bounds of charged lepton flavor-violating $l_i\to l_j\gamma$ and $l_i\to 3l_j$ channels. These bounds emanate from the extended Higgs sector of the model. Subsequently, we evaluate the one-loop contributions of the model to magnetic dipole moment (MDM) and electric dipole moment (EDM), which provide insights into the model's estimations for AMM and CP violation of charged leptons based on the experimental bounds of the aforementioned processes. The outcomes of this analysis will shed light on whether the Parity Manifest Minimal Left-Right Symmetric Model stands as a highly promising candidate for physics beyond the Standard Model.

   hep-ph0 citations
10. 10*

    Topological $SU(3{)}_f$ approach for two-body ${\Omega }_c$ weak decays

    Y. L. Wang🇨🇳 · H. J. Zhao🇨🇳 · Y. K. Hsiao🇨🇳

    We explore the two-body non-leptonic weak decays of ${\Omega }_c^0$ into final states ${\mathbf{B}}^{(\ast )}M$ and ${\mathbf{B}}^{(\ast )}V$, where ${\mathbf{B}}^{(\ast )}$ denotes an octet (a decuplet) baryon and $M(V)$ represents a pseudoscalar (vector) meson. We employ the topological $SU(3{)}_f$ approach to depict and parameterize the $W$-emission and $W$-exchange processes. We find that the topological parameters can be associated and combined, making them extractable for calculation. Consequently, we explain the partially measured branching fractions relative to $\mathcal{B}({\Omega }_c^0\to {\Omega }^{-}{\pi }^{+})$, recombined or kept as the following ratios: $\mathcal{B}({\Omega }_c^0\to {\Xi }^{\ast 0}{\bar{K}}^{\ast 0})/\mathcal{B}({\Omega }_c^0\to {\Omega }^{-}{\rho }^{+})=0.28\pm 0.11$, $\mathcal{B}({\Omega }_c^0\to {\Xi }^{-}{\pi }^{+})/\mathcal{B}({\Omega }_c^0\to {\Xi }^0{\bar{K}}^0)=0.10\pm 0.02$, and $\mathcal{B}({\Omega }_c^0\to {\Omega }^{-}{K}^{+})/\mathcal{B}({\Omega }_c^0\to {\Omega }^{-}{\pi }^{+})=0.06\pm 0.01$. In particular, we present $\mathcal{B}({\Omega }_c^0\to {\Xi }^0{\pi }^0)=(2.3\pm 0.2)\times 10^{-4}$ as half the value of $\mathcal{B}({\Omega }_c^0\to {\Xi }^{-}{\pi }^{+})$ in the approximate isospin relation, and highlight potential candidates for testing $SU(3{)}_f$ symmetry breaking.

    hep-phhep-exPRD(2025)·12 citations
11. 11*

    Impact of Medium Anisotropy on Quarkonium Dissociation and Regeneration

    Captain R. Singh🇮🇳 · Mohammad Yousuf Jamal · Raghunath Sahoo🇮🇳

    Quarkonium production in ultra-relativistic collisions plays a crucial role in probing the existence of hot QCD matter. This study explores quarkonia states dissociation and regeneration in the hot QCD medium while considering momentum anisotropy. The net quarkonia decay width (${\Gamma }_D$) arises from two essential processes: collisional damping and gluonic dissociation. The quarkonia regeneration includes the transition from octet to singlet states within the anisotropic medium. Our study utilizes a medium-modified potential that incorporates anisotropy via particle distribution functions. This modified potential gives rise to collisional damping for quarkonia due to the surrounding medium, as well as the transition of quarkonia from singlet to octet states due to interactions with gluons. Furthermore, we employ the detailed balance approach to investigate the regeneration of quarkonia within this medium. Our comprehensive analysis spans various temperature settings, transverse momentum values, and anisotropic strengths. Notably, we find that, in addition to medium temperatures and heavy quark transverse momentum, anisotropy significantly influences the dissociation and regeneration of various quarkonia states.

    hep-phhep-exnucl-exnucl-thEPJC(2024)·9 citations
12. 12*

    The rotation effect on the thermodynamics of the QCD matter

    Fei Sun🇨🇳 · Shuang Li🇨🇳 · Rui Wen🇨🇳 · Anping Huang🇨🇳 · Wei Xie🇨🇳

    In this study, we investigate the impact of rotation on the thermodynamic characteristics of QCD matter using the three-flavor NJL model. We examine the temperature, quark chemical potential, and angular velocity dependencies of key thermodynamic quantities, such as the trace anomaly, specific heat, speed of sound, angular momentum, and moment of inertia. As the main finding of our analysis, we observe that the speed of sound exhibits a nonmonotonic behavior as the angular velocity changes.

    hep-phCPC(2025)·11 citations
13. 13*

    Towards higher-order collinear splittings with massive partons

    Prasanna K. Dhani🇪🇸 · Germán Rodrigo🇪🇸 · German F. R. Sborlini🇪🇸

    The singularities associated with QCD factorization in the collinear limit are key ingredients for high-precision theoretical predictions in particle physics. They govern the collinear behaviour of scattering amplitudes, as well as the perturbative energy evolution of parton densities (PDFs) and fragmentation functions (FFs). In this talk, we present the computation of multiple collinear and higher-order QCD splittings with massive partons. Our results are highly-relevant for the consistent introduction of mass effects in the subtraction formalism and PDF/FF evolution.

    hep-phhep-exnucl-thPoS(2024)·0 citations
14. 14*

    Studying the production mechanisms of light meson resonances in two-pion photoproduction: a Regge approach

    Łukasz Bibrzycki🇵🇱 · Nadine Hammoud🇵🇱 · Vincent Mathieu🇪🇸 · Robert J. Perry🇪🇸 · Adam P. Szczepaniak🇺🇸

    A calculation of the angular moments of two-pion photoproduction is presented. The underlying theoretical model encodes the prominent $\rho (770)$ resonance and the expected leading background contribution coming from the Deck mechanism. The model contains a number of free parameters which are fit to experimental data. A good description of the angular moments is obtained.

    hep-phnucl-thNuovo Cim.C(2024)·0 citations
15. 15*

    Charmonium decays of beauty baryons in the perturbative QCD approach

    Zhou Rui🇨🇳 · Zhi-Tian Zou🇨🇳

    Motivated by recent advances in experimental measurements of heavy baryon decays, the charmonium decays of single $b$-baryon are investigated systematically in the framework of perturbative QCD approach. We calculate the decay branching ratios and helicity amplitudes as well as many pertinent decay asymmetry parameters that characterize the angular decay distributions. In particular, we estimate the fragmentation fractions of $b$ quark to $b$-baryons based on the current world averages of the branching ratio multiplied by fragmentation fraction. Some of the featured results are compared with the predictions of other approaches and experimental data. We also evaluate the branching ratios and angular asymmetries of the ${\Sigma }_b$ and ${\Xi }_b^{\prime }$ decay modes, which have neither been measured experimentally nor calculated theoretically. Our results could be helpful for a future experimental search for them and provide deeper insights in the understanding of the dynamics of heavy-flavor weak decay processes.

    hep-phPRD(2024)·14 citations
16. 16*

    Nonperturbative photon $q\bar{q}$ light front wave functions from a contact interaction model

    Chao Shi🇨🇳 · Zhongtian Yang🇨🇳 · Xurong Chen🇨🇳 · Wenbao Jia🇨🇳 · Cuibai Luo🇨🇳 · Wenchang Xiang🇨🇳

    We propose a method to calculate the $q\bar{q}$ light front wave functions (LFWFs) of photon at low-virtuality, i.e., the light front amplitude of ${\gamma }^{\ast }\to q\bar{q}$ at low $Q^2$, based on a light front projection approach. We exemplify this method using a contact interaction model within Dyson-Schwinger equations formalism and obtain the nonperturbative photon $q\bar{q}$ LFWFs. In this case, we find the nonperturbative effects are encoded in the enhanced quark mass and a dressing function of covariant quark-photon vertex, as compared to the leading order quantum electrodynamics photon $q\bar{q}$ LFWFs. We then use nonperturbative-effect modified photon $q\bar{q}$ LFWFs to study the inclusive deep inelastic scattering HERA data in the framework of the color dipole model. The results demonstrate that the theoretical description of data at low $Q^2$ can be significantly improved once the nonperturbative corrections are included in the photon LFWFs.

    hep-phnucl-thPRD(2024)·6 citations
17. 17*

    Heavy quark transverse momentum dependent fragmentation

    Lin Dai🇩🇪 · Chul Kim🇰🇷 · Adam K. Leibovich🇺🇸

    In this paper, we investigate the heavy quark (HQ) mass effects on the transverse momentum dependent fragmentation function (TMDFF). We first calculate the one-loop TMDFF initiated by a heavy quark. We then investigate the HQ TMDFF in the limit where the transverse momentum, $q_{\perp }$ is small compared to the heavy quark mass, $q_{\perp }\ll m$ and also in the opposite limit where $q_{\perp }\gg m$. As applications of the HQ TMDFF, we study the HQ transverse momentum dependent jet fragmentation function, where the heavy quark fragments into a jet containing a heavy hadron, and we investigate a heavy hadron's transverse momentum dependent distribution with respect to the thrust axis in $e^{+}{e}^{-}$ collisions.

    hep-phJHEP(2024)·15 citations
18. 18*

    $J/\psi$ decays into $\omega (\varphi )f_1(1285)$ and $\omega (\varphi ){}^{\prime \prime }{f}_1(1420{)}^{\prime \prime }$

    Jia-Xin Lin🇨🇳 · Jia-Ting Li🇨🇳 · Wei-Hong Liang🇨🇳 · Hua-Xing Chen🇨🇳 · Eulogio Oset🇪🇸

    We perform a theoretical study of the $J/\psi \to \omega (\varphi )K^{\ast }\bar{K}+c.c.\to \omega (\varphi )K^0{\pi }^{+}{K}^{-}$ reactions with the assumption that the $f_1(1285)$ is dynamically generated from a single channel $K^{\ast }\bar{K}+c.c$ interaction in the chiral unitary approach. Two peaks in the $K^0{\pi }^{+}{K}^{-}$ invariant mass distribution are observed, one clear peak locates at the $f_1(1285)$ nominal mass, the other peak locates at around $1420\mathrm{MeV}$ with about $70\mathrm{MeV}$ width. We conclude that the former peak is associated with the $f_1(1285)$ and the latter peak is not a genuine resonance but a manifestation of the kinematic effect in the higher energy region caused by the $K^{\ast }\bar{K}+c.c.$ decay mode of the $f_1(1285)$.

    hep-phEPJC(2024)·2 citations
19. 19*

    Washout processes in post-sphaleron baryogenesis from way-out-of-equilibrium decays

    J. Racker🇦🇷

    We study washout processes in post-sphaleron baryogenesis, a mechanism where the matter-antimatter asymmetry is generated in the decay of exotic particles after the electroweak phase transition. In particular we focus, in a quite model independent way, on those scattering processes that have an amplitude proportional to the CP asymmetry. We find that when the scatterings involve only massless particles, the washouts are very severe for light decaying particles (with masses below a few hundred of GeV) and successful baryogenesis is only possible in a small portion of parameter space. Instead, if even a very light particle participates in these processes, the allowed region of parameter space opens considerably, although the final amount of baryon asymmetry may differ significantly from the expression which is typically used and neglects washouts. Furthermore, we analyze washouts from the non-thermal spectrum of energetic particles produced in cascade decays and indicate in which models they can be relevant.

    hep-phEPJC(2024)·1 citation
20. 20*

    Towards higher-order calculations of quarkonia production with $k_T$-factorization: $P$-wave charmonia

    S.P. Baranov🇷🇺 · A.V. Lipatov🇷🇺 · A.A. Prokhorov🇷🇺 · X. Chen🇨🇳

    Inclusive $P$-wave charmonia production in hadronic collisions at high energies is discussed in the framework of non-relativistic QCD and $k_T$-factorization formalism. We present two consistent approches to merge the usual leading order $k_T$-factorization calculations with tree-level next-to-leading order off-shell amplitudes. Using these prescriptions, we extracted long-distance matrix elements for ${\chi }_c$ mesons from a combined fit to available Tevatron and LHC data. In contrast to previous (leading order) calculations, our fits do not contradict equal color singlet wave functions of ${\chi }_{c1}$ and ${\chi }_{c2}$ states. The extracted values of long-distance matrix elements are employed to analyse the ${\chi }_c$ polarization data reported recently by the CMS Collaboration. Our predictions are in a reasonably good agreement with the Tevatron and LHC measurements within the theoretical and experimental uncertainties.

    hep-phEPJC(2024)·5 citations
21. 21*

    Extraction of information on transversity GPDs from ${\pi }^0$ and $\eta$ production on EIC of China

    Ya-Ping Xie🇨🇳 · S. V. Goloskokov🇷🇺 · Xurong Chen🇨🇳

    The General Parton Distributions (GPDs) are applied to study the hard Pseudoscalar Meson Production (PMP) at high energies. The PMP amplitudes are be obtained within the GPDs factorization. They are expressed in terms of GPDs convolution functions, which are most essential in PMP reactions. We show that these convolution functions can be extracted from the PMP data in future EIC of China (EicC). Predictions of ${\pi }^0$ and $\eta$ production at typical EicC energies are performed.

    hep-phPhys.Atom.Nucl.(2024)·2 citations
22. 22*

    A Cosmic Window on the Dark Axion Portal

    Heejoung Hong🇬🇧 · Ui Min🇰🇷 · Minho Son🇰🇷 · Tevong You

    Axions and dark photons are common in many extensions of the Standard Model. The dark axion portal -- an axion coupling to the dark photon and photon -- can significantly modify their phenomenology. We study the cosmological constraints on the dark axion portal from Cosmic Microwave Background (CMB) bounds on the energy density of dark radiation, $\Delta N_{\text{eff}}$. By computing the axion-photon-dark photon collision terms and solving the Boltzmann equations including their effects, we find that light axions are generally more constrained by $\Delta N_{\text{eff}}$ than from supernova cooling or collider experiments. However, with dark photons at the MeV scale, a window of parameter space is opened up above the supernova limits and below the experimental exclusion, allowing for axion decay constants as low as $f_a\sim 10^4$ GeV. This region also modifies indirectly the neutrino energy density, thus relaxing the cosmological upper bound on the sum of neutrino masses. Future CMB measurements could detect a signal or close this open window on the dark axion portal.

    hep-phJHEP(2024)·12 citations
23. 23*

    AutoEFT: Constructing and exploring on-shell bases of effective field theories

    Magnus C. Schaaf🇩🇪

    Effective Field Theories (EFTs) provide a framework for capturing the effects of yet unseen heavy degrees of freedom in a model-independent manner. However, constructing a complete and minimal set of operators, especially at higher mass dimensions, is challenging. We present AutoEFT, an implementation of an algorithm that systematically handles redundancies among operators due to equations of motion, integration-by-parts identities, Fierz identities, and repeated fields. This algorithm enables the construction of on-shell bases for a broad range of EFTs. Additionally, it facilitates the exploration of various aspects within this field, such as investigating higher mass dimensions or the relationship between different operator bases. AutoEFT can be applied to phenomenologically relevant theories like the Standard Model and its extensions, including new light particles or additional symmetry groups.

    hep-phPoS(2024)·3 citations
24. 24*

    Exploring SMEFT Couplings Using the Forward-Backward Asymmetry in Neutral Current Drell-Yan Production at the LHC

    Andrii Anataichuk🇺🇦 · Sven-Olaf Moch🇩🇪 · Hamed Abdolmaleki🇮🇷 · Simone Amoroso🇩🇪 · Daniel Britzger🇩🇪 · Filippo Dattola🇩🇪 · Juri Fiaschi🇬🇧 · Francesco Giuli🇨🇭 · Alexander Glazov🇩🇪 · Francesco Hautmann🇨🇭 · Agnieszka Luszczak🇵🇱 · Sara Taheri Monfared🇩🇪 and 3 other authors

    Neutral current Drell-Yan (DY) lepton-pair production is considered in the framework of the Standard Model Effective Field Theory (SMEFT). Using the open-source fit platform xFitter, we investigate the impact of high-statistics measurements of the neutral current DY (NCDY) forward-backward asymmetry $A_{\mathrm{FB}}$ near the weak boson mass scale in the present and forthcoming stages of the Large Hadron Collider (LHC). Besides recovering earlier results on the $A_{\mathrm{FB}}$ sensitivity to parton distribution functions, we analyze the precision determination of $Z$-boson couplings to left-handed and right-handed $u$-quarks and $d$-quarks, and explore Beyond-Standard-Model contributions using the SMEFT framework. We perform a sensitivity study and comment on the role of the $A_{\mathrm{FB}}$ asymmetry for the electroweak SMEFT fit and precision $Z$-boson physics at the LHC and high-luminosity HL-LHC.

    hep-phEPJC(2024)·12 citations
25. 25*

    The colourful antenna subtraction method

    T. Gehrmann🇨🇭 · E. W. N. Glover🇬🇧 · M. Marcoli🇨🇭

    We present a general subtraction scheme for NNLO calculations in massless QCD: the \textit{colourful antenna subtraction method}. It is a reformulation of the antenna subtraction approach designed to address some of the limitations of the traditional framework, especially aiming at high-multiplicity processes. In the context of the new formalism, structures needed to locally subtract the infrared-divergent behaviour of real emission corrections are systematically inferred from virtual subtraction terms, relying on the cancellation of infrared singularities and on the correspondence between integrated and unintegrated antenna functions. We illustrate in detail how the colourful antenna subtraction method works up to NNLO. The algorithm is particularly suited to be fully automated for the generation of NNLO subtraction terms for generic processes. We employ the new formalism to assemble the subtraction terms required for the calculation of the NNLO correction to hadronic three-jet production and describe their validation procedure.

    hep-phJHEP(2024)·28 citations
26. 26*

    Soft modes in hot QCD matter

    Jens Braun🇩🇪 · Yong-rui Chen🇨🇳 · Wei-jie Fu🇨🇳 · Fei Gao🇨🇳 · Chuang Huang🇨🇳 · Friederike Ihssen🇩🇪 · Jan M. Pawlowski🇩🇪 · Fabian Rennecke🇩🇪 · Franz R. Sattler🇩🇪 · Yang-yang Tan🇨🇳 · Rui Wen🇨🇳 · Shi Yin🇨🇳

    The chiral crossover of QCD at finite temperature and vanishing baryon density turns into a second order phase transition if lighter than physical quark masses are considered. If this transition occurs sufficiently close to the physical point, its universal critical behaviour would largely control the physics of the QCD phase transition. We quantify the size of this region in QCD using functional approaches, both Dyson-Schwinger equations and the functional renormalisation group. The latter allows us to study both critical and non-critical effects on equal footing, facilitating a precise determination of the scaling regime. We find that the physical point is far away from the critical region. Importantly, we show that the physics of the chiral crossover is dominated by soft modes even far beyond the critical region. While scaling functions determine all thermodynamic properties of the system in the critical region, the order parameter potential is the relevant quantity away from it. We compute this potential in QCD using the functional renormalisation group and Dyson-Schwinger equations and provide a simple parametrisation for phenomenological applications.

    hep-phhep-lathep-thnucl-thPRD(2025)·53 citations
27. 27*

    Quantum Parton Shower with Kinematics

    Christian W. Bauer🇺🇸 · So Chigusa🇺🇸 · Masahito Yamazaki🇯🇵

    Parton showers which can efficiently incorporate quantum interference effects have been shown to be run efficiently on quantum computers. However, so far these quantum parton showers did not include the full kinematical information required to reconstruct an event, which in classical parton showers requires the use of a veto algorithm. In this work, we show that adding one extra assumption about the discretization of the evolution variable allows to construct a quantum veto algorithm, which reproduces the full quantum interference in the event, and allows to include kinematical effects. We finally show that for certain initial states the quantum interference effects generated in this veto algorithm are classically tractable, such that an efficient classical algorithm can be devised.

    hep-phquant-phPRA(2024)·21 citations
28. 28*

    Two Loop Renormalization of Scalar Theories using a Geometric Approach

    Elizabeth E. Jenkins🇺🇸 · Aneesh V. Manohar🇺🇸 · Luca Naterop🇨🇭 · Julie Pagès🇺🇸

    We derive a general formula for two-loop counterterms in Effective Field Theories (EFTs) using a geometric approach. This formula allows the two-loop results of our previous paper to be applied to a wide range of theories. The two-loop results hold for loop graphs in EFTs where the interaction vertices contain operators of arbitrarily high dimension, but at most two derivatives. We also extend our previous one-loop result to include operators with an arbitrary number of derivatives, as long as there is at most one derivative acting on each field. The final result for the two-loop counterterms is written in terms of geometric quantities such as the Riemann curvature tensor of the scalar manifold and its covariant derivatives. As applications of our results, we give the two-loop counterterms and renormalization group equations for the O(n) EFT to dimension six, the scalar sector of the Standard Model Effective Field Theory (SMEFT) to dimension six, and chiral perturbation theory to order $p^6$.

    hep-phJHEP(2024)·67 citations
29. 29*

    On Fractional Analytic QCD

    A.V. Kotikov🇷🇺 · I.A. Zemlyakov🇷🇺

    We present a brief overview of fractional analytic QCD.

    hep-phPhys.Part.Nucl.(2024)·4 citations
30. 30*

    A loophole in the proofs of asymptotic freedom and quantum triviality

    Paul Romatschke🇺🇸

    In 1973, Coleman and Gross proved that in four dimensions, only non-abelian gauge theories can have asymptotic freedom. More recently, Aizenman and Duminil-Copin proved that four dimensional scalar field theories are quantum trivial in the continuum. Both of these proofs have a loophole, and it is the same loophole in both proofs: The proofs assume that the scalar self-coupling in the UV is positive definite. While this is a perfectly reasonable and classically very intuitive assumption, it is an assumption nevertheless. In this work, I show that the assumption of coupling positivity is violated in a concrete quantum field theory, the O(N) model, in the large N limit. Surprisingly, despite the classically nonsensical unbounded potential, the negative coupling has no pathological consequence for propagators, the free energy or cross sections. This suggests that interacting scalar field theories with asymptotic freedom in four dimensions are possible, despite long-held opinions to the contrary.

    ↳ hep-thhep-phnucl-thPoS(2024)·6 citations
31. 31*

    On the role of postulates in the understanding of Weyl gauge symmetry

    Israel Quiros🇲🇽

    Understanding of Weyl gauge symmetry is rarely associated with underlying postulates. Here we show that such an omission leads to discrepancies in regard to the reach and consequences of gauge symmetry within gravitational theories. Replacement of the postulates which underlie the conventional approach, by just the opposite assumptions, leads to a radically different interpretation of Weyl gauge symmetry, which shares the same mathematical foundations and carries observational consequences.

    ↳ gr-qchep-ph0 citations
32. 32*

    $T$-matrix Analysis of Static Wilson Line Correlators from Lattice QCD at Finite Temperature

    Zhanduo Tang🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Ralf Rapp🇺🇸

    We utilize a previously constructed thermodynamic $T$-matrix approach to the quark-gluon plasma (QGP) to calculate Wilson line correlators (WLCs) of a static quark-antiquark pair and apply them to the results from 2+1-flavor lattice-QCD (lQCD) computations with realistic pion mass. The self-consistent $T$-matrix results, which include constraints from the lQCD equation of state in the light-parton sector, can describe the lQCD data for WLCs fairly well once refinements of the input parameters are implemented. In particular, the input potential requires less screening than used in previous $T$-matrix analyses. Pertinent predictions for the spectral and transport properties of the QGP are discussed, including the spatial diffusion coefficient for heavy quarks which turns out to have a rather weak temperature dependence, in approximate agreement with recent lQCD results.

    ↳ hep-lathep-phnucl-thEPJA(2024)·37 citations
33. 33*

    Transversity PDFs of the proton from lattice QCD with physical quark masses

    Xiang Gao🇺🇸 · Andrew D. Hanlon🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Qi Shi🇺🇸 · Sergey Syritsyn🇺🇸 · Yong Zhao🇺🇸

    We present a lattice QCD calculation of the transversity isovector- and isoscalar-quark parton distribution functions (PDFs) of the proton utilizing a perturbative matching at next-to-leading-order (NLO) accuracy. Additionally, we determine the isovector and isoscalar tensor charges for the proton. In both calculations, the disconnected contributions to the isoscalar matrix elements have been ignored. The calculations are performed using a single ensemble of $N_f=2+1$ highly-improved staggered quarks simulated with physical-mass quarks and a lattice spacing of $a=0.076$ fm. The Wilson-clover action, with physical quark masses and smeared gauge links obtained from one iteration of hypercubic smearing, is used in the valence sector. Using the NLO operator product expansion, we extract the lowest four to six Mellin moments and the PDFs via a neural network from the matrix elements in the pseudo-PDF approach. In addition, we calculate the PDFs in the quasi-PDF approach with hybrid-scheme renormalization and the recently developed leading-renormalon resummation technique, at NLO with the resummation of leading small-$x$ logarithms.

    ↳ hep-lathep-exhep-phnucl-ex+1PRD(2024)·40 citations
34. 34*

    One-loop thermal radiation exchange in gravitational wave power spectrum

    Atsuhisa Ota🇨🇳 · Misao Sasaki🇯🇵 · Yi Wang🇨🇳

    The radiation-dominated universe is a key ingredient of the standard Big Bang cosmology. Radiation comprises numerous quantum elementary particles, and the macroscopic behavior of radiation is described by taking the quantum thermal average of its constituents. While the interactions between individual particles and gravitational waves are often neglected in this context, it raises the question of whether these elementary particles interact with gravitational waves in the framework of quantum field theory. To address this question, this paper aims to explore the quantum mechanical aspects of gravitational waves in a universe dominated by a massless scalar field, whose averaged energy-momentum tensor plays the role of background radiation. We establish the equivalence between the classical Einstein equation and the mean-field approximation of the Heisenberg equation in a local thermal state. Beyond the mean-field approximation, we analyze the quantum corrections to gravitational waves, particularly focusing on the thermal radiation loop corrections. Interestingly, we find the 1-loop correction surpasses the tree-level spectrum of primordial gravitational waves, which is $O({\alpha }^2)$ where $\alpha =H_{\inf }/M_{\mathrm{pl}}$ is the ratio of the inflationary Hubble parameter to the Planck mass. Then, to see if this result persists even if we take into account all the higher order loop corrections, the loop expansion is reorganized in the series expansion in $\alpha$. We schematically discuss two-loop diagrams that may give $O({\alpha }^2)$ contributions. We leave explicit computations of these diagrams for future studies. Thus, although we cannot claim that the whole loop corrections exceed the tree-level spectrum at the moment, our findings highlight the significance of quantum effects when studying the interaction between radiation and gravitational waves in the cosmological context.

    ↳ astro-ph.COgr-qchep-phhep-thJHEP(2025)·11 citations
35. 35*

    Spectrum of gravitational waves from long-lasting primordial sources

    Sabir Ramazanov🇨🇿

    We discuss long-lasting gravitational wave sources arising and operating during radiation-dominated stage. Under a set of assumptions, we establish the correspondence between cosmological evolution of a source and the resulting gravitational wave spectrum. Namely, for the source energy density ${\rho }_s$ falling as a power law characterized by the exponent $\beta$, i.e., ${\rho }_s\propto 1/a^{\beta }$, where $a$ is the Universe scale factor, the spectrum takes the form ${\Omega }_{gw}\propto f^{2\beta -8}$ in certain ranges of values of constant $\beta$ and frequencies $f$. In particular, matching to the best fit power law shape of stochastic gravitational wave background discovered recently by Pulsar Timing Array collaborations, one identifies $\beta \approx 5$. We demonstrate the correspondence with concrete examples of long-lasting sources: domain walls and cosmic strings.

    ↳ gr-qcastro-ph.COhep-phhep-thJCAP(2024)·6 citations
36. 36*

    Electromagnetic current operators for phenomenological relativistic models

    Wayne Polyzou🇺🇸

    Background: Phenomenological Poincaré invariant quantum mechanical models can provide an efficient description of the dynamics of strongly interacting particles that is consistent with spectral and scattering observables. These models are representation dependent and in order to apply them to reactions with electromagnetic probes it is necessary to have a consistent electromagnetic current operator. Purpose: The purpose of this work is to use local gauge invariance to construct consistent strong current operators. Method: Current operators are constructed from a model Hamiltonian by replacing momentum operators in the Weyl representation by gauge covariant derivatives. Results: The construction provides a systematic method to construct explicit expressions for current operators that are consistent with relativistic models of strong interaction dynamics.

    ↳ nucl-thhep-phFew Body Syst.(2024)·2 citations
37. 37*

    Hartree-Fock Formulation of the QMC Model at Finite Temperature

    P A M Guichon🇫🇷 · J R Stone🇺🇸 · A W Thomas🇦🇺

    We present, for the first time, a detailed theory of high density matter including the entire baryon octet at finite temperature, based on a fully relativistic mean field model with a consistent treatment of exchange (Fock) terms, using the quark-meson-coupling model (QMC). It has been already demonstrated that the QMC equation of state is applicable in thermodynamic scenarios in stationary and rotating isentropic proto-neutron stars, producing results in agreement with recent observation. It is also suitable for the simulation of the behavior following a binary neutron star merger [1]; https://compose.obspm.fr/eos/205. We develop a comprehensive demonstration of the impact of the Fock terms in the QMC energy density functional on properties of neutrinoless proto-neutron stars with cores containing the full hyperon octet with constant entropy, S/A=2kB. Given the interest in the properties of the proto-neutron star remaining after either a supernova explosion or the merger of two neutron stars, it is vital to develop modern equations of state at finite temperature. While much attention has been paid to relativistic mean-field calculations at finite temperature, it is crucial to explore the consequences of a consistent treatment of the Fock terms.

    ↳ nucl-thastro-ph.HEastro-ph.SRhep-phPRD(2024)·6 citations
38. 38*

    Casimir Energy Stabilization of Standard Model Landscape in Dark Dimension

    Chuanxin Cui🇨🇳 · Sirui Ning🇬🇧

    In this paper we present a realization of dark dimension. We consider the 5D standard model coupling to gravity with one dimension compactified on an orbifold, which is seen as dark dimension of size R. We stabilize the radion by casimir effect wrapping around compact dimension and recover the neutrino mass and 4D cosmological constant with the observed value. Orbifold can lead to a natural resolution of chirality problem in 5D at low energy, which we briefly discussed in the paper. Although we found that the radion mass is too light to survive under solar system tests of GR, several screening mechanisms might give us a solution, for example, Chameleon mechanism.

    ↳ hep-thhep-phJHEP(2026)·7 citations
39. 39*

    Particle content of very inclined air showers for radio signal modeling

    Marion Guelfand🇫🇷 · Simon Chiche🇫🇷 · Kumiko Kotera🇫🇷 · Simon Prunet🇫🇷 · Tanguy Pierog🇩🇪

    The reconstruction of very inclined air showers is a new challenge for next-generation radio experiments such as the AugerPrime radio upgrade, BEACON, and GRAND, which focus on the detection of ultra-high-energy particles. To tackle this, we study the electromagnetic particle content of very inclined air showers, which has scarcely been studied so far. Using the simulation tools CORSIKA and CoREAS, and analytical modeling, we explore the energy range of the particles that contribute most to the radio emission, quantify their lateral extent, and estimate the atmospheric depth at which the radio emission is strongest. We find that the distribution of the electromagnetic component in very inclined air showers has characteristic features that could lead to clear signatures in the radio signal, and hence impact the reconstruction strategies of next-generation radio-detection experiments.

    ↳ astro-ph.HEhep-phJCAP(2024)·7 citations
40. 40*

    ULDM self-interactions, tidal effects and tunnelling out of satellite galaxies

    Bihag Dave🇮🇳 · Gaurav Goswami🇮🇳

    It is well-known that Dark Matter (DM) inside a satellite galaxy orbiting a host halo experiences a tidal potential. If DM is ultra-light, given its wave-like nature, one expects it to tunnel out of the satellite - if this happens sufficiently quickly, then the satellite will not survive over cosmological timescales, severely constraining this dark matter model. In this paper, we study the effects of the inevitable quartic self-interaction of scalar Ultra-Light Dark Matter (ULDM) on the lifetimes of satellite galaxies by looking for quasi-stationary solutions with outgoing wave boundary conditions. For a satellite with some known core mass and orbital period, we find that, attractive (repulsive) self-interactions decrease (increase) the rate of tunnelling of DM out of it. In particular, for satellite galaxies with core mass $\sim \mathcal{O}(10^7-10^8)M_{\odot }$ and orbital period $\sim \mathcal{O}(1)\text{Gyr}$, one can impose constraints on the strength of self-interactions as small as $\lambda \sim \mathcal{O}(10^{-92})$. For instance, for ULDM mass $m=10^{-22}\text{eV}$, the existence of the Fornax dwarf galaxy necessitates attractive self-interactions with $\lambda \lesssim -2.12\times 10^{-91}$.

    ↳ astro-ph.COhep-phJCAP(2024)·16 citations
41. 41*

    Building Momentum Kernel from Shapovalov Form

    Chih-Hao Fu🇨🇳 · Yihong Wang🇨🇳

    These notes are an extended version of the talks given by the authors at the XIV International Workshop on Lie Theory and Its Applications in Physics, Sofia, Bulgaria, 20-26 June 2021. The concise version published in the proceedings of the workshop contains additional discussions for the $q$-deformed scenario: \noindent\href{https://link.springer.com/chapter/10.1007/978-981-19-4751-3_23}{https://link.springer.com/chapter/10.1007/978-981-19-4751-3\_23}. In these notes we identify KLT kernel with the Shapovalov form on Verma module with its highest/lowest weight given by the reference momentum and rest of the momenta as roots. We then take a step forward and show how the Feynman diagrams emerge naturally as the Shapovalov duals of the Verma module basis vectors. We show such algebraic construct offers a compact expression for the BCJ numerators. Explicit examples are shown for the nonlinear sigma model and the HEFT pre-numerators.

    ↳ hep-thhep-phmath.QASpringer Proc.Math.Stat.(2022)·2 citations
42. 42*

    Core and Halo Properties in Multi-Field Wave Dark Matter

    Fabio van Dissel🇪🇸 · Mark P. Hertzberg🇺🇸 · Jared Shapiro🇺🇸

    In this work, we compute multi-field core and halo properties in wave Dark Matter models. We focus on the case where Dark Matter consists of two light (real) scalars, interacting gravitationally. As in the single-field Ultra Light Dark Matter (ULDM) case, the scalar field behaves as a coherent BEC with a definite ground state (at fixed total mass), often referred to in the literature as a gravitational soliton. We establish an efficient algorithm to find the ground and excited states of such two-field systems. We then use simulations to investigate the gravitational collapse and virialization, starting from different initial conditions, into solitons and surrounding halo. As in the single-field case, a virialized halo forms with a gravitational soliton (ground state) at the center. We find some evidence for an empirical relation between the soliton mass and energy and those of the host halo. We use this to then find a numerical relation between the properties of the two. Finally, we use this to address the issue of alleviating some of the tensions that single-field ULDM has with observational data, in particular, the issue of how a galaxy's core and radius are related. We find that if galaxies of different masses have similar percentages of the two species, then the core-radius scaling tension is not addressed. However, more general possibilities occur if the relative abundance of species in each halo correlates with the total mass of the galaxy. If this is the case, the model predicts several other phenomenological signatures.

    ↳ astro-ph.COhep-phhep-thJCAP(2024)·10 citations
43. 43*

    Finite-Temperature Instantons from First Principles

    Thomas Steingasser🇺🇸 · Morgane König🇺🇸 · David I. Kaiser🇺🇸

    We derive the finite-temperature quantum-tunneling rate from first principles. The rate depends on both real- and imaginary-time; we demonstrate that the relevant instantons should therefore be defined on a Schwinger-Keldysh contour, and how the familiar Euclidean-time result arises from it in the limit of large physical times. We generalize previous results for general initial states, and identify distinct behavior in the high- and low-temperature limits, incorporating effects from background fields. We construct a consistent perturbative scheme that incorporates large finite-temperature effects.

    ↳ hep-thhep-phPRD(2024)·24 citations
44. 44*

    Detectable MeV Neutrino Signals from Neutron-Star Common-Envelope Systems

    Ivan Esteban🇺🇸 · John F. Beacom🇺🇸 · Joachim Kopp🇨🇭

    Common-envelope evolution - where a star is engulfed by a companion - is a critical but poorly understood step in, e.g., the formation pathways for gravitational-wave sources. However, it has been extremely challenging to identify observable signatures of such systems. We show that for systems involving a neutron star, the hypothesized super-Eddington accretion onto the neutron star produces MeV-range, months-long neutrino signals within reach of present and planned detectors. While there are substantial uncertainties on the rate of such events (0.01-1/century in the Milky Way) and the neutrino luminosity (which may be less than the accretion power), this signal can only be found if dedicated new analyses are developed. If detected, the neutrino signal would probe super-Eddington accretion, leading to significant new insights into the astrophysics of common-envelope evolution.

    ↳ astro-ph.HEhep-exhep-phPRL(2025)·7 citations
45. 45*

    Double parton scattering versus jet quenching

    S. P. Baranov🇷🇺 · A. V. Lipatov🇷🇺 · M. A. Malyshev🇷🇺 · A. M. Snigirev🇷🇺

    A novel observable, the double nuclear modification factor, is proposed to probe simultaneously the initial and final state effects in nucleus-nucleus collisions. An interesting competition between the combinatorial enhancement in the double parton scattering and the suppression due to parton energy loss can be observed in the production rate of two hard particles. In particular, the production of $J/\psi$ mesons in association with a $W$ boson is not suppressed but is enhanced in the region of moderate transverse momenta, unlike the case of unassociated (inclusive) $J/\psi$ production. At the same time, in the region of high enough transverse momenta the nuclear modification factor for associated $J/\psi +W$ production converges to that of unassociated $J/\psi$.

    ↳ nucl-thhep-phJETP Lett.(2024)·1 citation

* 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.