Wed·Dec 20, 2023Wednesday·December 20, 2023

1. 01*

   Coherent gluon radiation: beyond leading-log accuracy

   Greg Jackson🇺🇸 · Stéphane Peigné🇫🇷 · Kazuhiro Watanabe🇫🇷

   Results are presented for the medium-induced, soft coherent radiation spectrum for all $2\to 2$ partonic channels in QCD, at leading-order in ${\alpha }_s$ but beyond leading logarithmic accuracy. The general formula is valid in the full kinematic range of the underlying process, and reduces to previous results in special cases. The soft gluon radiation spectrum is expressed in terms of the color density matrix specific to each channel, quantifying the entanglement between the color components of the $2\to 2$ production amplitude. Beyond the leading logarithm, the spectrum depends explicitly on the off-diagonal elements of this matrix, owing to the soft gluon's ability to probe the internal color structure of the parton pair.

   hep-phJHEP(2024)·3 citations
2. 02*

   Wee partons in QCD and gravity: double copy and universality

   Himanshu Raj🇺🇸 · Raju Venugopalan🇺🇸

   We discuss a quantitative "double copy" between radiation from shockwave collisions in Einstein gravity and in QCD. The correspondence extends to $2\to N$ amplitudes in Regge asymptotics. The classicalization and unitarization of these amplitudes at maximal occupancy, corresponding to black hole and Color Glass Condensate (CGC) states respectively, are described by the emergent Goldstone dynamics of wee partons. We outline some consequences of the universal dynamics on both sides of the correspondence.

   hep-phgr-qchep-thnucl-thEPJ Web Conf.(2024)·2 citations
3. 03*

   Tidal Disruption Events and Dark Matter Scatterings with Neutrinos and Photons

   Motoko Fujiwara🇩🇪 · Gonzalo Herrera🇺🇸

   Stars can be tidally disrupted when passing near a black hole, and the debris can induce a flux of high-energy neutrinos. It has been discussed that there are hints in IceCube data of high-energy neutrinos produced in Tidal Disruption Events. The emitting region of neutrinos and photons in these astrophysical events is likely to be located in the vicinity of the central black hole, where the dark matter density might be significantly larger than in the outer regions of the galaxy. We explore the potential attenuation of the emitted neutrino and photon fluxes due to interactions with dark matter particles around the supermassive black hole of the host galaxies of AT2019dsg, AT2019fdr and AT2019aalc, and study the implications for some well-motivated models of dark matter-neutrino and dark matter-photon interactions. Furthermore, we discuss the complementarity of our constraints with values of the dark matter-neutrino scattering cross section proven to alleviate some cosmological tensions.

   hep-phastro-ph.COPLB(2024)·26 citations
4. 04*

   Ultralight dark matter in long-baseline accelerator neutrino oscillations

   Xin-Qiang Li🇨🇳 · Hai-Xing Lin🇨🇳 · Jian Tang🇨🇳 · Sampsa Vihonen🇸🇪

   We present a systematic study of the effects of ultralight dark matter (ULDM) on neutrino oscillations using the latest long-baseline data from the T2K and NO$\nu$A experiments. Our analysis covers both flavor-universal and flavor-general scalar interactions, as well as vector interactions associated with the $L_e-L_{\mu }$ and $L_{\mu }-L_{\tau }$ gauge symmetries. Importantly, we explicitly consider the coherence properties of the ULDM by incorporating the resulting stochastic fluctuations into our statistical analysis. We find that in the low-mass regime, $m_{\varphi }\lesssim 10^{-17}$ eV, where the stochastic effects are maximal, the constraints on the ULDM couplings are relaxed by roughly an order of magnitude compared to those in the high-mass regime,$m_{\varphi }\gtrsim 10^{-15}$ eV, where such fluctuations are effectively averaged out. While the combined T2K and NO$\nu$A datasets impose nontrivial exclusion limits on the ULDM interactions, we do not find statistically significant evidence that these effects can alleviate the current tension in determining the charge-parity (CP) violating phase ${\delta }_{CP}$ between the two experiments. Therefore, it will be essential for future high-precision facilities to further probe the ULDM scenarios and achieve a definitive measurement of ${\delta }_{CP}$.

   hep-phhep-exPRD(2026)·12 citations
5. 05*

   The force-force correlator at the hard thermal scale of hot QCD

   Jacopo Ghiglieri🇫🇷 · Philipp Schicho🇩🇪 · Niels Schlusser🇨🇭 · Eamonn Weitz🇫🇷

   High-energy particles traversing the Quark-Gluon plasma experience modified (massive) dispersion, although their vacuum mass is negligible compared to the kinetic energy. Due to poor convergence of the perturbative series in the regime of soft loop momenta, a more precise determination of this effective mass is needed. This paper continues our investigation on the factorisation between strongly-coupled infrared classical and perturbative ultraviolet behavior. The former has been studied non-perturbatively within EQCD by determining a non-local operator on the lattice. By computing the temperature-scale contribution to the same operator in 4D QCD at next-to-leading order (NLO), we remove the ultraviolet divergence of the EQCD calculation with an opposite infrared divergence from the hard thermal scale. The result is a consistent, regulator-independent determination of the classical contribution where the emergence of new divergences signals sensitivities to new regions of phase space. We address the numerical impact of the classical and NLO thermal corrections on the convergence of the factorised approach and on the partial applicability of our results to calculations of transport coefficients.

   hep-phJHEP(2024)·1 citation
6. 06*

   Neutrino spin oscillation in screening models revisited

   Fayçal Hammad🇨🇦 · Nicolas Fleury🇨🇦 · Parvaneh Sadeghi🇨🇦

   We study, using the Mathisson-Papapetrou-Dixon equations, the spin oscillation of neutrinos when the latter are coupled to the scalar field of screening models of dark energy. First, we derive the transition probability formula for a left-handed neutrino to become a right-handed neutrino within a general static and spherically symmetric metric. We then apply our general formula to neutrinos deflected around a central mass described by the Schwarzschild metric. Our results show that, contrary to what one might expect, the scalar field of chameleon-like and symmetron-like screening models would not show any effect on the spin oscillations of neutrinos. The origin of such an outcome is discussed.

   hep-phgr-qcPRD(2023)·4 citations
7. 07*

   Jet Classification Using High-Level Features from Anatomy of Top Jets

   Amon Furuichi🇯🇵 · Sung Hak Lim🇺🇸 · Mihoko M. Nojiri🇯🇵

   Recent advancements in deep learning models have significantly enhanced jet classification performance by analyzing low-level features (LLFs). However, this approach often leads to less interpretable models, emphasizing the need to understand the decision-making process and to identify the high-level features (HLFs) crucial for explaining jet classification. To address this, we consider the top jet tagging problems and introduce an analysis model (AM) that analyzes selected HLFs designed to capture important features of top jets. Our AM mainly consists of the following three modules: a relation network analyzing two-point energy correlations, mathematical morphology and Minkowski functionals for generalizing jet constituent multiplicities, and a recursive neural network analyzing subjet constituent multiplicity to enhance sensitivity to subjet color charges. We demonstrate that our AM achieves performance comparable to the Particle Transformer (ParT) while requiring fewer computational resources in a comparison of top jet tagging using jets simulated at the hadronic calorimeter angular resolution scale. Furthermore, as a more constrained architecture than ParT, the AM exhibits smaller training uncertainties because of the bias-variance tradeoff. We also compare the information content of AM and ParT by decorrelating the features already learned by AM. Lastly, we briefly comment on the results of AM with finer angular resolution inputs.

   hep-phhep-exJHEP(2024)·8 citations
8. 08*

   CP phase in modular flavor models and discrete Froggatt-Nielsen models

   Shota Kikuchi🇯🇵 · Tatsuo Kobayashi🇯🇵 · Kaito Nasu🇯🇵

   We study the large mass hierarchy and CP violation in the modular symmetric quark flavor models without fine-tuning. Mass matrices are written in terms of modular forms. Modular forms near the modular fixed points are approximately given by ${\epsilon }^p$, where $\epsilon$ and $p$ denote the small deviation from the fixed points and their residual charges. Thus mass matrices have the hierarchical structures depending on the residual charges, and have a possibility describing the large mass hierarchy without fine-tuning. Similar structures of mass matrices are also obtained in Froggatt-Nielsen models. Nevertheless, it seems to be difficult to induce a sufficient amount of CP violation by a single small complex parameter $\epsilon$. To realize the large mass hierarchy as well as sizable CP violation, multi-moduli are required. We show the mass matrix structures with multi-moduli which are consistent with quark flavor observables including CP phase. We also discuss the origins of the large mass hierarchy and CP violation in such mass matrix structures.

   hep-phPRD(2024)·13 citations
9. 09*

   Can femtoscopic correlation function shed light on the nature of the lightest, charm, axial mesons?

   K. P. Khemchandani🇧🇷 · Luciano M. Abreu🇧🇷 · A. Martinez Torres🇧🇷 · F. S. Navarra🇧🇷

   We present a coupled channel treatment of meson-meson dynamics, for systems with spin-parity $1^{+}$, and determine the corresponding amplitudes by solving the Bethe-Salpeter equations, which lead to the generation of two axial resonances when mesons are considered as the degrees of freedom in the model. One of them is narrow and has properties in good agreement with those of $D_1(2420)$. The other pole is wider, but its real and imaginary parts do not match well with the mass and width of $D_1(2430)$. The situation improves when a bare quark-model state is included, indicating that the dynamics at the quark level as well as among hadrons can describe the two states simultaneously. Further, we discuss that there exists a divergence in the value of the $D^{\ast }\pi$ scattering length determined through data coming from lattice QCD calculations and from heavy ion collisions. Such different values can be accommodated in the model by making small changes in the parameters while producing two poles having properties compatible with the two lightest $D_1$ states. With these results, we proceed to calculate the correlation function for the $D^{\ast +(0)}{\pi }^{0(+)}$ system for different sizes of the source. We discuss which scenarios can be useful to shed some light on the issue.

   hep-phPRD(2024)·25 citations
10. 10*

    Higgs Quadruplet Impact on $W$ Mass Shift, Dark Matter, and LHC Signatures

    Talal Ahmed Chowdhury🇧🇩 · Kareem Ezzat🇪🇬 · Shaaban Khalil🇪🇬 · Ernest Ma🇺🇸 · Dibyendu Nanda🇰🇷

    The addition of a Higgs quadruplet to the standard model (SM) of quarks and leptons would shift the $W$ boson mass upward. It could also facilitate the production of dark matter through the conventional thermal freeze-out scenario via Yukawa interaction with the Higgs quadruplet or freeze-in production from the decay of SM Higgs. We investigate the same-sign lepton smoking gun signature of the double-charged scalar component of the Quadruplet Higgs at the LHC.

    hep-phPRD(2024)·4 citations
11. 11*

    Searches for Additional Scalars at Future $e^{+}{e}^{-}$ Colliders

    Karabo Mosala🇿🇦 · Thuso Mathaha🇿🇦 · Mukesh Kumar🇿🇦 · Bruce Mellado🇿🇦

    We present growing excesses consistent with a 95 GeV scalar. We provide a comprehensive analysis of the Two Higgs Doublet Model and an additional singlet (2HDM+S) at future $e^{+}{e}^{-}$ collider. In particular, we provide a precise mass reconstruction measurement for the scalar, $m_S$, using the recoil mass method through $e^{+}{e}^{-}\to ZS$ where $Z\to {\mu }_{+}{\mu }_{-}$ and $S\to b\bar{b}$ at $\sqrt{s}=250$~GeV and $\sqrt{s}=200$~GeV. Furthermore, we employ Deep Neural Network to analyze the properties and behaviour of the scalar particle with a mass most importantly to provide enhanced resolution for the separation between beyond the Standard Model (SM) signal and SM background in the region 95 - 96 GeV in the $S\to b\bar{b}$ for ${\mu }_{+}{\mu }_{-}$ channel. A 95 GeV scalar can be observed with $5\sigma$ significance at $15(10)$ fb${}^{-1}$ integrated luminosity for $\sqrt{s}=250(200)$~GeV. This strengthens the discovery of the potential of the future $e^{+}{e}^{-}$ collider.

    hep-ph0 citations
12. 12*

    Thermalization and Annihilation of Dark Matter in Neutron Stars

    Nicole F. Bell🇦🇺 · Giorgio Busoni🇦🇺 · Sandra Robles🇬🇧 · Michael Virgato🇦🇺

    The capture of dark matter, and its subsequent annihilation, can heat old, isolated neutron stars. In order for kinetic heating to be achieved, the captured dark matter must undergo sufficient scattering to deposit its kinetic energy in the star. We find that this energy deposit typically occurs quickly, for most of the relevant parameter space. In order for appreciable annihilation heating to also be achieved, the dark matter must reach a state of capture-annihilation equilibrium in the star. We show that this can be fulfilled for all types of dark matter - baryon interactions. This includes cases where the scattering or annihilation cross sections are momentum or velocity suppressed in the non-relativistic limit. Importantly, we find that capture-annihilation equilibrium, and hence maximal annihilation heating, can be achieved without complete thermalization of the captured dark matter. For scattering cross sections that saturate the capture rate, we find that capture-annihilation equilibrium is typically reached on a timescale of less than $1$ year for vector interactions and $10^4$ years for scalar interactions.

    hep-phastro-ph.COastro-ph.HEJCAP(2024)·47 citations
13. 13*

    On order ${\Lambda }_{\mathrm{QCD}}^2/m$ renormalons in quarkonium system

    Takuya Agemura🇯🇵 · Yukinari Sumino🇯🇵

    For the heavy quarkonium system we examine $\mathcal{O}({\Lambda }_{\mathrm{QCD}}^2/m)$ renormalons, which are expected to be included in the perturbative series of the pole mass and $1/(m{r}^2)$ interquark potential. We find indications of existence and cancellation of these renormalons, from examinations of stability and convergence properties of the perturbative series and their resummations, as well as by comparison with the known properties of the $\mathcal{O}({\Lambda }_{\mathrm{QCD}})$ renormalons.

    hep-phPLB(2024)·0 citations
14. 14*

    Correlation function for the $a_0(980)$

    R. Molina🇪🇸 · Zhi-Wei Liu🇨🇳 · Li-Sheng Geng🇨🇳 · E. Oset🇪🇸

    We have conducted a model independent analysis of the $K^{+}{\bar{K}}^0$ pair correlation function obtained from ultra high energy $pp$ collisions, with the aim of extracting the information encoded in it related to the $K\bar{K}$ interaction and the coupled channel ${\pi }^{+}\eta$. With the present large errors at small relative $K^{+}{\bar{K}}^0$ momenta, we find that the information obtained about the scattering matrix suffers from large uncertainties. Even then, we are able to show that the data imply the existence of the $a_0$ resonance, $a_0(980)$, showing as a strong cusp close to the $K\bar{K}$ threshold. We also mention that the measurement of the ${\pi }^{+}\eta$ correlation function will be essential in order to constrain more the information on $K\bar{K}$ dynamics that can be obtained from correlation functions.

    hep-phhep-exEPJC(2024)·26 citations
15. 15*

    Stripping triangle loops: Discussion of $D_s^{+}\to {\rho }^{+}\eta \to {\pi }^{+}{\pi }^0\eta$ in $a_0(980)$ production

    M. Bayar🇹🇷 · R. Molina🇪🇸 · E. Oset🇪🇸 · Ming-Zhu Liu🇨🇳 · Li-Sheng Geng🇨🇳

    We address a general problem in the evaluation of triangle loops stemming from the consideration of the range of the interaction involved in some of the vertices, as well as the energy dependence of the width of some unstable particles in the loop. We find sizeable corrections from both effects. We apply that to a loop relevant to the $D_s^{+}\to {\pi }^{+}{\pi }^0\eta$ decay, and find reductions of about a factor of $4$ in the mass distribution of invariant mass of the $\pi \eta$ in the region of the $a_0(980)$. The method used is based on the explicit analytical evaluation of the $q^0$ integration in the $d^{4}q$ loop integration, using Cauchy's residues method, which at the same time offers an insight on the convergence of the integrals and the effect of form factors and cutoffs.

    hep-phPRD(2024)·9 citations
16. 16*

    Glueballs from Dyson-Schwinger and Bethe-Salpeter equations

    Markus Q. Huber🇩🇪 · Christian S. Fischer🇩🇪 · Hèlios Sanchis-Alepuz🇦🇹

    The quenched spectrum of glueballs with positive charge parity is calculated from two-body bound state equations. As input, a self-contained solution for the primitively divergent correlation functions from Dyson-Schwinger equations is used. It only has one parameter to be set which is the physical scale. An important feature of this setup is the consistent construction of the bound state kernels along the same lines as the equations from which the input was obtained. Keeping only the one-particle exchanges, already good agreement with lattice results is obtained. For the tensor glueball, we present first results including two-loop contributions, elevating its calculation to the same level of truncation as for the spin zero glueballs for which such calculations have been done previously.

    hep-phhep-thNuovo Cim.C(2024)·4 citations
17. 17*

    Neutron-antineutron oscillation accompanied by CP-violation in magnetic fields

    Yongliang Hao🇨🇳 · Kamphamba Sokalao Nyirenda🇨🇳 · Zhenwei Chen🇨🇳

    In this work, we explore the possibility of the $n$-$\bar{n}$ oscillation accompanied by CP-violation in the presence of magnetic fields. The $n$-$\bar{n}$ oscillation, which violates the baryon number ($\mathcal{B}$) by two units ($|\Delta \mathcal{B}|=2$), can be originated from the mixing between the neutron ($n$) and the neutral elementary particle ($\eta$) and may give rise to non-trivial effects that are different from previous theoretical predictions. We show that the probability of the $n$-$\bar{n}$ oscillation can be greatly enhanced by adjusting the magnetic field properly. In particular, the peak values of the oscillation probability in the presence of resonance magnetic fields can be $8$-$10$ orders of magnitude higher than that in the absence of magnetic fields. We point out that there might not be sizable CP-violating effects in the $n$-$\bar{n}$ oscillation unless the mass of $\eta$ is close to the mass of the neutron. We also analyze the interplay between various parameters associated with both $\mathcal{B}$-violation and CP-violation and attempt to disentangle the effects of such parameters. The $n$-$\bar{n}$ oscillation process accompanied by CP-violation may open a promising avenue for exploring new physics beyond the Standard Model (SM).

    hep-phJ.Phys.G(2024)·0 citations
18. 18*

    Primordial Black Hole Sterile Neutrinogenesis: Sterile Neutrino Dark Matter Production Independent of Couplings

    Muping Chen🇺🇸 · Graciela B. Gelmini🇺🇸 · Philip Lu🇰🇷 · Volodymyr Takhistov🇯🇵

    Sterile neutrinos (${\nu }_s$s) are well-motivated and actively searched for hypothetical neutral particles that would mix with the Standard Model active neutrinos. They are considered prime warm dark matter (DM) candidates, typically when their mass is in the keV range, although they can also be hot or cold DM components. We discuss in detail the characteristics and phenomenology of ${\nu }_s$s that minimally couple only to active neutrinos and are produced in the evaporation of early Universe primordial black holes (PBHs), a process we called "PBH sterile neutrinogenesis". Contrary to the previously studied ${\nu }_s$ production mechanisms, this novel mechanism does not depend on the active-sterile mixing. The resulting ${\nu }_s$s have a distinctive spectrum and are produced with larger energies than in typical scenarios. This characteristic enables ${\nu }_s$s to be WDM in the unusual $0.3$ MeV to $0.3$ TeV mass range, if PBHs do not matter-dominate the Universe before evaporating. When PBHs matter-dominate before evaporating, the possible coincidence of induced gravitational waves associated with PBH evaporation and astrophysical X-ray observations from ${\nu }_s$ decays constitutes a distinct signature of our scenario. constitutes a distinct signature of our scenario.

    hep-phastro-ph.COastro-ph.HEJCAP(2024)·22 citations
19. 19*

    Heavy quark momentum diffusion coefficient during hydrodynamization via effective kinetic theory

    Kirill Boguslavski🇦🇹 · Aleksi Kurkela🇳🇴 · Tuomas Lappi🇫🇮 · Florian Lindenbauer🇦🇹 · Jarkko Peuron🇫🇮

    In these proceedings, we compute the heavy quark momentum diffusion coefficient using QCD effective kinetic theory for a plasma going through the bottom-up thermalization scenario until approximate hydrodynamization. This transport coefficient describes heavy quark momentum diffusion in the quark-gluon plasma and is used in many phenomenological frameworks, e.g. in the open quantum systems approach. Our extracted nonthermal diffusion coefficient matches the thermal one for the same energy density within 30\%. At large occupation numbers in the earliest stage, the transverse diffusion coefficient dominates, while the longitudinal diffusion coefficient is larger for the underoccupied system in the later stage of hydrodynamization.

    hep-phnucl-thEPJ Web Conf.(2024)·1 citation
20. 20*

    Stochastic Ultralight Dark Matter Fluctuations in Pulsar Timing Arrays

    Hyungjin Kim🇩🇪 · Andrea Mitridate🇩🇪

    Metric perturbations induced by ultralight dark matter (ULDM) fields have long been identified as a potential target for pulsar timing array (PTA) observations. Previous works have focused on the coherent oscillation of metric perturbations at the characteristic frequency set by the ULDM mass. In this work, we show that ULDM fields source low-frequency stochastic metric fluctuations and that these low-frequency fluctuations can produce distinctive detectable signals in PTA data. Using the NANOGrav 12.5-year data set and synthetic data sets mimicking present and future PTA capabilities, we show that the current and future PTA observations provide the strongest probe of ULDM density within the solar system for masses in the range of $10^{-18}\mathrm{eV}-10^{-16}\mathrm{eV}$.

    hep-phPRD(2024)·41 citations
21. 21*

    On the high-energy behavior of massive QCD amplitudes

    Guoxing Wang🇫🇷 · Tianya Xia🇨🇳 · Li Lin Yang🇨🇳 · Xiaoping Ye🇨🇳

    In this note, we propose a factorization formula for gauge-theory scattering amplitudes up to two loops in the high-energy boosted limit. Our formula extends existing results in the literature by incorporating the contributions from massive loops. We derive the new ingredients in our formula using the method of regions with analytic regulators for the rapidity divergences. We verify our results with various form factors and the scattering amplitudes for top-quark pair production. Our results can be used to obtain approximate expressions for complicated two-loop massive amplitudes from simpler massless ones, and can be used to resum the mass logarithms to all orders in the coupling constant.

    hep-phJHEP(2024)·29 citations
22. 22*

    Celestial Objects as Dark Matter Colliders

    Thong T. Q. Nguyen🇹🇼

    In the vicinity of the Milky Way Galactic Center, celestial bodies, including neutron stars, reside within a dense dark matter environment. This study explores the accumulation of dark matter by neutron stars through dark matter-nucleon interactions, leading to increased internal dark matter density. Consequently, dark matter annihilation produces long-lived mediators that escape and decay into neutrinos. Leveraging experimental limits from IceCube, ANTARES, and future projections from ARIA, we establish constraints on the dark matter-nucleon cross section within a simplified dark $U(1{)}_X$ mediator model. This approach, applicable to various celestial objects and dark matter models, offers insights into the intricate interplay between dark matter and neutron stars near the Galactic Center.

    hep-phastro-ph.COastro-ph.HE3 citations
23. 23*

    Quarkonium transport in weakly and strongly coupled plasmas

    Govert Nijs🇨🇭 · Bruno Scheihing-Hitschfeld🇺🇸 · Xiaojun Yao🇺🇸

    We report on progress in the nonperturbative understanding of quarkonium dynamics inside a thermal plasma. The time evolution of small-size quarkonium is governed by two-point correlation functions of chromoelectric fields dressed with an adjoint Wilson line, known in this context as generalized gluon distributions (GGDs). The GGDs have been calculated in both weakly and strongly coupled plasmas by using perturbative and holographic methods. Strikingly, the results of our calculations for a strongly coupled plasma indicate that the quarkonium dissociation and recombination rates vanish in the transport descriptions that assume quarkonium undergoes Markovian dynamics. However, this does not imply that the dynamics is trivial. As a starting point to explore the phenomenological consequences of the result at strong coupling, we show a calculation of the ${\rm Y}(1S)$ formation probability in time-dependent perturbation theory. This is a first step towards the development of a transport formalism that includes non-Markovian effects, which, depending on how close the as of yet undetermined nonperturbative QCD result of the GGDs is to the strongly coupled $\mathcal{N}=4$ SYM result, could very well dominate over the Markovian ones in quark-gluon plasma produced at RHIC and the LHC.

    hep-phnucl-thEPJ Web Conf.(2024)·6 citations
24. 24*

    Self Interacting Dark Matter and Dirac neutrinos via Lepton Quarticity

    Satyabrata Mahapatra🇰🇷 · Sujit Kumar Sahoo🇮🇳 · Narendra Sahu🇮🇳 · Vicky Singh Thounaojam🇮🇳

    In this paper, we put forward a connection between the self-interacting dark matter and the Dirac nature of neutrinos. Our exploration involves a $Z_4\otimes Z_4^{\prime }$ discrete symmetry, wherein the Dirac neutrino mass is produced through a type-I seesaw mechanism. This symmetry not only contributes to the generation of the Dirac neutrino mass but also facilitates the realization of self-interacting dark matter with a light mediator that can alleviate small-scale anomalies of the $\Lambda \mathrm{CDM}$ while being consistent with the latter at large scales, as suggested by astrophysical observations. Thus the stability of the DM and Dirac nature of neutrinos are shown to stem from the same underlying symmetry. The model also features additional relativistic degrees of freedom $\Delta N_{\mathrm{eff}}$ of either thermal or non-thermal origin, within the reach of cosmic microwave background (CMB) experiment providing a complementary probe in addition to the detection prospects of DM.

    hep-phastro-ph.COPRD(2024)·13 citations
25. 25*

    An Algebraic Roadmap of Particle Theories, Part I: General construction

    N. Furey🇩🇪

    Expanding the results of [1], [2], [3], we demonstrate a network of algebraic connections between six well-known particle theories. These are the Spin(10) model, the Georgi-Glashow model, the Pati-Salam model, the Left-Right Symmetric model, the Standard Model both pre- and post-Higgs mechanism. A new inclusion of a quaternionic reflection within the network further differentiates $W^{\pm }$ bosons from the $Z^0$ boson in comparison to the Standard Model. It may introduce subtle new considerations for the phenomenology of electroweak symmetry breaking.

    hep-phhep-thAnnalen Phys.(2025)·11 citations
26. 26*

    Interference Effects in $\mathbf{gg}\to \mathbf{H}\to \mathbf{Z}\gamma$ Beyond Leading Order

    Federico Buccioni🇩🇪 · Federica Devoto🇬🇧 · Abdelhak Djouadi🇪🇸 · John Ellis🇬🇧 · Jérémie Quevillon🇫🇷 · Lorenzo Tancredi🇩🇪

    The ATLAS and CMS collaborations at the LHC have recently announced evidence for the rare Higgs boson decay into a $Z$ boson and a photon. We analyze the interference between the process $gg\to H\to Z\gamma$ induced by loops of heavy particles, which is by far the dominant contribution to the signal, and the continuum $gg\to Z\gamma$ QCD background process mediated by light quark loops. This interference modifies the event yield, the resonance line-shape and the apparent mass of the Higgs boson. We calculate the radiative corrections to this interference beyond the leading-order approximation in perturbative QCD and find that, while differing numerically from the corresponding effects on the more studied $gg\to \gamma \gamma$ signal, they are generally rather small. As such, they do not impact significantly the interpretation of the present measurements of the $H\to Z\gamma$ decay mode.

    hep-phhep-exPLB(2024)·18 citations
27. 27*

    Introducing the concept of the Widom line in the QCD phase diagram

    G. Sordi🇬🇧 · A.-M. S. Tremblay🇨🇦

    Critical phenomena emerging from the critical end point of a first-order transition are ubiquitous in nature. Here we bring the concept of a supercritical crossover, the Widom line, initially developed in the context of fluids, into the interacting matter described by quantum chromodynamics (QCD). We show that the existence of the putative critical end point between hadron gas and quark-gluon plasma in the temperature versus chemical potential of the QCD phase diagram implies the existence of a Widom line emerging from it in the supercritical region. We survey the thermodynamic anomalies already identified in simplified theoretical models of QCD exhibiting a critical end point, to show that they can be interpreted in terms of a Widom line. Then we suggest possible directions where the Widom line concept could provide new light on the QCD phase diagram.

    hep-phnucl-thPRD(2024)·8 citations
28. 28*

    Gravitational waves from supercooled phase transitions: dimensional transmutation meets dimensional reduction

    Maciej Kierkla🇵🇱 · Bogumila Swiezewska🇵🇱 · Tuomas V. I. Tenkanen🇫🇮 · Jorinde van de Vis🇳🇱

    Models with radiative symmetry breaking typically feature strongly supercooled first-order phase transitions, which result in an observable stochastic gravitational wave background. In this work, we analyse the role of higher order thermal corrections for these transitions, applying high-temperature dimensional reduction to a theory with dimensional transmutation. In particular, we study to what extent high-temperature effective field theories (3D EFT) can be used. We find that despite significant supercooling down from the critical temperature, the high-temperature expansion for the bubble nucleation rate can be applied using the 3D EFT framework, and we point out challenges in the EFT description. We compare our findings to previous studies, and find that the next-to-leading order corrections obtained in this work have a significant effect on the predictions for GW observables, motivating a further exploration of higher order thermal effects.

    hep-phastro-ph.COJHEP(2024)·71 citations
29. 29*

    Searching for Axial Neutral Current Non-Standard Interactions of neutrinos by DUNE-like experiments

    Saeed Abbaslu🇮🇷 · Mehran Dehpour🇮🇷 · Yasaman Farzan🇮🇷 · Sahar Safari🇮🇷

    The increasingly precise neutrino experiments raise the hope for searching for new physics through studying the impact of Neutral Current (NC) Non-Standard Interactions (NSI) of neutrinos with matter fields. Neutrino oscillation experiments along with the Elastic Coherent $\nu$ Nucleus Scattering (CE$\nu$NS) experiments already set strong bounds on all the flavor elements of the "vector" NC NSI. However, "axial" NC NSI can hide from these experiments. We show how a DUNE-like experiment can probe these couplings by studying NC Deep Inelastic Scattering (DIS) events. We find that strong bounds can be set on the axial NC NSI of neutrinos with the $u$, $d$, and $s$ quarks. We show that using both the near and far detectors, a DUNE-like experiment can significantly improve the present bounds on all the flavor elements.

    hep-phhep-exJHEP(2024)·11 citations
30. 30*

    Neutron Stars as the Dark Matter detectors

    Ariel Zhitnitsky🇨🇦

    It has been known for quite sometime that the Neutron Stars (NS) can play a role of the Dark Matter (DM) detectors due to many uniques features of NS. We apply these (previously developed) ideas to a specific form of the DM when it is represented by a composite object, rather than by a local fundamental field (such as WIMPs). To be more precise we consider the so-called axion quark nuggets (AQN) dark matter model, when the ``non-baryonic" dark matter in fact is made of quarks and gluons which are in dense quark phase (similar to the old idea of the Witten's strangelets). We argue that the interaction of the AQNs with NS material may lead to many profound observable effects, which dramatically different from conventional picture when DM particles are represented by weakly interacting WIMPs. In particular, we argue that the AQNs may serve as the triggers for the magnetic reconnection to heat the NS surface. This effect may strongly alleviate (or even completely remove) the observed inconsistencies between the predicted and observed surface temperatures for many old NS. This heating mechanism is always accompanied by the hard X ray emission, which may serve as an indicator of the proposed mechanism.

    hep-phastro-ph.HEastro-ph.SRPRD(2024)·5 citations
31. 31*

    Staying on Top of SMEFT-Likelihood Analyses

    Nina Elmer🇩🇪 · Maeve Madigan🇩🇪 · Tilman Plehn🇩🇪 · Nikita Schmal🇩🇪

    We present a new global SMEFT analysis of LHC data in the top sector. After updating our set of measurements, we show how public ATLAS likelihoods can be incorporated into an external global analysis and how our analysis benefits from the additional information. We find that, unlike for the Higgs and electroweak sector, the SMEFT analysis of the top sector is mostly limited by the theory uncertainties. Finally, we present the first global SFitter analysis combining the top and electroweak-Higgs sectors.

    hep-phSciPost Phys.(2025)·31 citations
32. 32*

    The Impact of LHC Jet and $Z$ $p_T$ Data at up to Approximate N${}^3$LO Order in the MSHT Global PDF Fit

    T. Cridge🇩🇪 · L. A. Harland-Lang🇬🇧 · R. S. Thorne🇬🇧

    We present an analysis of two key sets of data constraining the high $x$ gluon at up to approximate N${}^3$LO in QCD within the MSHT global PDF fitting framework. We begin with LHC 7 and 8 TeV inclusive jet and dijet production at both NNLO and aN${}^3$LO. This makes use of the formalism established in the previous global MSHT20aN${}^3$LO PDF fit, but now considers the role of dijet production for the first time at this order. We present a detailed comparison of the fit quality and PDF impact for both cases, and consider the role that electroweak corrections, and the scale choice for inclusive jet production has. Some mild tension between these data sets in the impact on the high $x$ gluon is seen at NNLO, but this is largely eliminated at aN${}^3$LO. While a good fit quality to the dijet data is achieved at both orders, the fit quality to the inclusive jet data is relatively poor. We examine the impact of including full colour corrections in a global PDF fit for the first time, finding this to be relatively mild. We also revisit the fit to the ATLAS 8 TeV $Z$ $p_T$ data, considering the role that the $p_T$ cuts, data selection and different aspects of the aN${}^3$LO treatment have on the fit quality and PDF impact. We observe that in all cases the aN${}^3$LO fit quality is consistently improved relative to the NNLO, indicating a clear preference for higher order theory for these data.

    hep-phhep-exEPJC(2024)·20 citations
33. 33*

    Decoding the $B\to K\nu \nu$ excess at Belle II: kinematics, operators, and masses

    Kåre Fridell🇯🇵 · Mitrajyoti Ghosh🇺🇸 · Takemichi Okui🇺🇸 · Kohsaku Tobioka🇺🇸

    An excess in the branching fraction for $B^{+}\to K^{+}\nu \nu$ recently measured at Belle II may be a hint of new physics. We perform thorough likelihood analyses for different new physics scenarios such as $B\to KX$ with a new invisible particle $X$, or $B\to K\chi \chi$ through a scalar, vector, or tensor current with $\chi$ being a new invisible particle or a neutrino. We find that vector-current 3-body decay with $m_X\simeq 0.6$ GeV - which may be dark matter - is most favored, while 2-body decay with $m_X\simeq 2$ GeV is also competitive. The best-fit branching fractions for the scalar and tensor cases are a few times larger than for the 2-body and vector cases. Past BaBar measurements provide further discrimination, although the best-fit parameters stay similar.

    hep-phhep-exPRD(2024)·64 citations
34. 34*

    Optimal New Physics estimation in presence of Standard Model backgrounds

    Subhaditya Bhattacharya🇮🇳 · Sahabub Jahedi🇮🇳 · Jayita Lahiri🇩🇪 · Jose Wudka🇺🇸

    In this work, we develop a numerical technique for the optimal estimation of the new physics (NP) couplings applicable to any collider process without any simplifying assumptions. This approach also provides a way to measure the quality of the NP estimates derived using standard ${\chi }^2$ analysis and can be used to gauge the advantages of various modalities of collider design. We illustrate the techniques and arguments by considering the pair production of heavy charged fermions at an $e^{+}{e}^{-}$ collider.

    hep-phPRD(2025)·4 citations
35. 35*

    Heavy Quark Fragmentation in $e^{+}{e}^{-}$ Collisions to NNLO+NNLL Accuracy in Perturbative QCD

    Leonardo Bonino🇨🇭 · Matteo Cacciari🇫🇷 · Giovanni Stagnitto🇨🇭

    Fragmentation of heavy quarks into heavy-flavoured hadrons receives both perturbative and non-perturbative contributions. We consider perturbative QCD corrections to heavy quark production in $e^{+}{e}^{-}$ collisions to next-to-next-to-leading order accuracy in QCD with next-to-next-to-leading-logarithmic resummation of quasi-collinear and soft emissions. We study multiple matching schemes, and multiple regularisations of the soft resummation, and observe a significant dependence of the perturbative results on these ingredients, suggesting that NNLO+NNLL perturbative accuracy may not lead to real gains unless the interface with non-perturbative physics is properly analysed. We confirm previous evidence that $D^{\ast +}$ experimental data from CLEO/BELLE and from LEP are not reconcilable with perturbative predictions employing standard DGLAP evolution. We extract non-perturbative contributions from $e^{+}{e}^{-}$ experimental data for both $D$ and $B$ meson fragmentation. Such contributions can be used to predict heavy-quark fragmentation in other processes, e.g. DIS and proton-proton collisions.

    hep-phJHEP(2024)·21 citations
36. 36*

    Searching Dark Photons using displaced vertices at Belle II -- with backgrounds

    Joerg Jaeckel🇩🇪 · Anh Vu Phan🇳🇱

    Dark photons in the MeV to GeV range with kinetic mixing of the order of $\lesssim 10^{-4}-10^{-3}$ can be produced in significant numbers at low energy colliders such as Belle II. Their decay length can be macroscopic raising the hope for a fairly clean search via displaced vertices as proposed in Ref. [1]. However, even this is not background free. Here, we calculate and discuss problematic backgrounds from displaced photon conversion and discuss their potential impact on the sensitivity. In addition we also briefly consider the dangers of prompt backgrounds.

    hep-phhep-exJHEP(2024)·12 citations
37. 37*

    Flavour-changing top quark decays in the alternative left-right model

    Mariana Frank🇨🇦 · Benjamin Fuks🇫🇷 · Sumit K. Garg🇮🇳 · Poulose Poulose🇮🇳

    We examine flavour-changing neutral-current decays of the top quark, $t\to q\gamma$, $t\to qZ$, $t\to qH$, and $t\to qg$ (with $q=u,c$), in the Alternative Left-Right Model, a left right-symmetric model featuring exotic quarks and light bosons. These decays have a very small probability of occurring within the Standard Model, but they can be enhanced in this model through the presence of the exotic states. While associated signals may be detected directly at the LHC, rare decays have the advantage of offering means to probe new particles indirectly, through loop-contributions. We perform a comprehensive analysis of the model's parameter space to demonstrate the possible existence of enhancements in the corresponding branching ratios, of $10^6$ for the branching ratios $\mathcal{B}(t\to uZ)$ and $\mathcal{B}(t\to uH)$, and in the range of $10^2-10^4$ for the other decays, relative to the Standard Model. We subsequently determine the preferred parameter space regions of the model in terms of potential of being reached in the near future.

    hep-phhep-exPLB(2024)·10 citations
38. 38*

    $\mathcal{C}\mathcal{P}$-violation sensitivity of closed-shell radium-containing polyatomic molecular ions

    Konstantin Gaul🇩🇪 · Nicholas R. Hutzler🇺🇸 · Phelan Yu🇺🇸 · Andrew M. Jayich🇺🇸 · Miroslav Iliaš🇸🇰 · Anastasia Borschevsky🇳🇱

    Closed-shell atoms and molecules such as Hg or TlF provide some of the best low-energy tests of hadronic $\mathcal{C}\mathcal{P}$-violation which is considered to be a necessary ingredient to explain the observed excess of matter over antimatter in our universe. $\mathcal{C}\mathcal{P}$-violation is, however, expected to be strongly enhanced in octupole deformed nuclei such as ${}^{225}$Ra. Recently, closed-shell radium-containing symmetric-top molecular ions were cooled sympathetically in a Coulomb crystal [M. Fan et al., Phys. Rev. Lett. 126, 023002 (2021)] and shown to be well-suited for precision spectroscopy in the search for fundamental physics [P. Yu and N. R. Hutzler, Phys. Rev. Lett. 126, 023003 (2021)]. In closed-shell molecules hadronic $\mathcal{C}\mathcal{P}$-violation contributes to a net electric dipole moment (EDM) that violates parity and time-reversal symmetry ($\mathcal{P},\mathcal{T}$), which is the target of measurements. To interpret experiments, it is indispensable to know the electronic structure enhancement parameters for the various sources of $\mathcal{P},\mathcal{T}$-violation which contribute to the net $\mathcal{P},\mathcal{T}$-odd EDM. In this paper we employ relativistic Hartree--Fock and density functional theory calculations to determine relevant parameters for interpretation of possible EDM measurements in RaOCH${}_3^{+}$, RaSH${}^{+}$, RaCH${}_3^{+}$, RaCN${}^{+}$, and RaNC${}^{+}$ and perform accurate relativistic coupled cluster calculations of the Schiff moment enhancement in RaSH${}^{+}$ to gauge the quality of the density functional theory approach. Finally, we project to bounds on various fundamental $\mathcal{P},\mathcal{T}$-odd parameters that could be achievable from an experiment with RaOCH${}_3^{+}$ in the near future and asses the complementarity of this experiment to experiments with Hg and TlF.

    ↳ physics.atom-phhep-phphysics.chem-phPRA(2024)·6 citations
39. 39*

    Constraints on Phase Transitions in Neutron Star Matter

    Len Brandes🇩🇪 · Wolfram Weise🇩🇪

    Recent inference results of the sound velocity in the cores of neutron stars are summarized. Implications for the equation of state and the phase structure of highly compressed baryonic matter are discussed. In view of the strong constraints imposed by the heaviest known pulsars, the equation of state must be very stiff in order to ensure the stability of these extreme objects. This required stiffness limits the possible appearance of phase transitions in neutron star cores. For example, a Bayes factor analysis quantifies strong evidence for squared sound velocities $c_s^2>0.1$ in the cores of 2.1 solar-mass and lighter neutron stars. Only weak first-order phase transitions with a small phase coexistence density range $\Delta \rho /\rho <0.2$ (at the 68\% level) in a Maxwell construction still turn out to be possible within neutron stars. The central baryon densities in even the heaviest neutron stars do not exceed five times the density of normal nuclear matter. In view of these data-based constraints, much discussed issues such as the quest for a phase transition towards restored chiral symmetry, and the active degrees of freedom in cold and dense baryonic matter, are reexamined.

    ↳ nucl-thastro-ph.HEhep-phnucl-exSymmetry(2024)·40 citations
40. 40*

    Quantum field theories of relativistic Luttinger fermions

    Holger Gies🇩🇪 · Philip Heinzel🇩🇪 · Johannes Laufkötter🇩🇪 · Marta Picciau🇩🇪

    We propose relativistic Luttinger fermions as a new ingredient for the construction of fundamental quantum field theories. We construct the corresponding Clifford algebra and the spin metric for relativistic invariance of the action using the spin-base invariant formalism. The corresponding minimal spinor has 32 complex components, matching with the degrees of freedom of a standard-model generation including a right-handed neutrino. The resulting fermion fields exhibit a canonical scaling different from Dirac fermions and thus support the construction of novel relativistic and perturbatively renormalizable, interacting quantum field theories. In particular, new asymptotically free self-interacting field theories can be constructed, representing first examples of high-energy complete quantum field theories based on pure matter degrees of freedom. Gauge theories with relativistic Luttinger fermions exhibit a strong paramagnetic dominance, requiring large nonabelian gauge groups to maintain asymptotic freedom. We comment on the possibility to use Luttinger fermions for particle physics model building and the expected naturalness properties of such models.

    ↳ hep-thcond-mat.str-elhep-phPRD(2024)·9 citations
41. 41*

    Asymptotic safety in the Litim-Sannino model at four loops

    A.V. Bednyakov🇷🇺 · A.I. Mukhaeva🇷🇺

    We consider a four-dimensional $SU(N_c)$ gauge theory coupled to $N_f$ species of color fermions and $N_f^2$ colorless scalars. The quantum field theory possesses a weakly interacting ultraviolet fixed point that we determine from beta functions computed up to four-loop order in the gauge coupling, and up to three-loop order in the Yukawa and quartic scalar couplings. The fixed point has one relevant direction giving rise to asymptotic safety. We compute fixed point values of dimensionless couplings together with the corresponding scaling exponents up to the first three nontrivial orders in Veneziano parameter $ϵ$, both for infinite and finite number of colors $N_c$. We also consider anomalous dimensions for fields, scalar mass squared, and a class of dimension-three operators. Contrary to previous studies, we take into account possible mixing of the latter and compute eigenvalues of the corresponding matrix. Further, we investigate the size of the conformal window in the Veneziano limit and its dependence on $N_c$.

    ↳ hep-thhep-phPRD(2024)·6 citations
42. 42*

    The $\theta$-dependence of the $\mathrm{SU}(N)$ critical temperature at large $N$

    Claudio Bonanno🇪🇸 · Massimo D'Elia🇮🇹 · Lorenzo Verzichelli🇮🇹

    We investigate, by means of numerical lattice simulations, the $\theta$-dependence of the critical deconfinement temperature of $\mathrm{SU}(N)$ gauge theories at large $N$: $T_c(\theta )=T_c(0)[1-R{\theta }^2+O({\theta }^4)]$, with $R\sim O(1/N^2)$. We follow two different strategies to determine $R$, one based on the calculation of the latent heat of the transition and on the jump of the topological susceptibility at the $\theta =0$ critical point, the other relying on a direct probe of $T_c(\theta )$ by means of imaginary-$\theta$ Monte Carlo simulations. Our results show that $R$ follows the expected large-$N$ scaling.

    ↳ hep-lathep-phhep-thJHEP(2024)·29 citations
43. 43*

    Secondary Vertex Reconstruction with MaskFormers

    Samuel Van Stroud🇬🇧 · Nikita Pond🇬🇧 · Max Hart🇬🇧 · Jackson Barr🇬🇧 · Sébastien Rettie🇬🇧 · Gabriel Facini🇬🇧 · Tim Scanlon🇬🇧

    In high-energy particle collisions, the reconstruction of secondary vertices from heavy-flavour hadron decays is crucial for identifying and studying jets initiated by $b$- or $c$-quarks. Traditional methods, while effective, require extensive manual optimisation and struggle to perform consistently across wide regions of phase space. Meanwhile, recent advancements in machine learning have improved performance but are unable to fully reconstruct multiple vertices. In this work we propose a novel approach to secondary vertex reconstruction based on recent advancements in object detection and computer vision. Our method directly predicts the presence and properties of an arbitrary number of vertices in a single model. This approach overcomes the limitations of existing techniques. Applied to simulated proton-proton collision events, our approach demonstrates significant improvements in vertex finding efficiency, achieving a 10% improvement over an existing state-of-the-art method. Moreover, it enables vertex fitting, providing accurate estimates of key vertex properties such as transverse momentum, radial flight distance, and angular displacement from the jet axis. When integrated into a flavour tagging pipeline, our method yields a 50% improvement in light-jet rejection and a 15% improvement in $c$-jet rejection at a $b$-jet selection efficiency of 70%. These results demonstrate the potential of adapting advanced object detection techniques for particle physics, and pave the way for more powerful and flexible reconstruction tools in high-energy physics experiments.

    ↳ hep-exhep-phEPJC(2024)·9 citations
44. 44*

    Heavy Quark Momentum Broadening in a Non-Abelian Plasma away from Thermal Equilibrium

    Harshit Pandey🇮🇳 · Soeren Schlichting🇩🇪 · Sayantan Sharma🇮🇳

    We perform classical-statistical real-time lattice simulations to compute real-time spectral functions and momentum broadening of quarks in the presence of strongly populated non-Abelian gauge fields. Based on a novel methodology to extract the momentum broadening for relativistic quarks, we find that the momentum distribution of quarks exhibit interesting non-perturbative features as a function of time due to correlated momentum kicks it receives from the medium, eventually going over to a diffusive regime. We extract the momentum diffusion coefficient for a mass range describing charm and bottom quarks and find sizeable discrepancies from the heavy quark limit.

    ↳ hep-lathep-phnucl-exnucl-thPRL(2024)·28 citations
45. 45*

    Anti-de Sitter $\to$ de Sitter transition driven by Casimir forces and mitigating tensions in cosmological parameters

    Luis A. Anchordoqui🇺🇸 · Ignatios Antoniadis🇫🇷 · Dieter Lust🇩🇪

    Over the last few years, low- and high-redshift observations set off tensions in the measurement of the present-day expansion rate $H_0$ and in the determination of the amplitude of the matter clustering in the late Universe (parameterized by $S_8$). It was recently noted that both these tensions can be resolved if the cosmological constant parametrizing the dark energy content switches its sign at a critical redshift $z_c\sim 2$. However, the anti-de Sitter (AdS) swampland conjecture suggests that the postulated switch in sign of the cosmological constant at zero temperature seems unlikely because the AdS vacua are an infinite distance appart from de Sitter (dS) vacua in moduli space. We provide an explanation for the required AdS $\to$ dS crossover transition in the vacuum energy using the Casimir forces of fields inhabiting the bulk. We then use entropy arguments to claim that any AdS $\to$ dS transition between metastable vacua must be accompanied by a reduction of the species scale where gravity becomes strong. We provide a few examples supporting this AdS $\to$ dS uplift conjecture.

    ↳ hep-thastro-ph.COgr-qchep-phPLB(2024)·56 citations
46. 46*

    Exact Tunneling Solutions in Multi-Field Potentials

    J. R. Espinosa🇪🇸 · T. Konstandin🇩🇪

    The tunneling potential formalism makes it easy to construct exact solutions to the vacuum decay problem in potentials with multiple fields. While some exact solutions for single-field decays were known, we present the first nontrivial analytic examples with two and three scalar fields, and show how the method can be generalized to include gravitational corrections. Our results illuminate some analytic properties of the tunneling potential functions and can have a number of uses, among others: to serve as simple approximations to realistic potentials; to learn about parametric dependencies of decay rates; to check conjectures on vacuum decay; as benchmarks for multi-field numerical codes; or to study holographic interpretations of vacuum decay.

    ↳ hep-thgr-qchep-phJCAP(2024)·8 citations
47. 47*

    Tracing baryon and electric charge transport in isobar collisions

    Gregoire Pihan🇺🇸 · Akihiko Monnai🇯🇵 · Björn Schenke🇺🇸 · Chun Shen🇺🇸

    It is of fundamental interest to understand the carrier of conserved quantum charges within protons and nuclei at high energy. Preliminary data from isobar collisions at RHIC reveal a scaled net-baryon to net-electric charge ratio ($B/\Delta Q\times \Delta Z/A$) at mid-rapidity between 1.2 and 2, consistent with string junction model predictions. Here, we compute the initial stage scaled net-baryon to net-electric charge ratio for isobar collisions. Our model incorporates a realization of the string junction model and models the nuclear structure. Our predictions identify the baseline expectations for such measurement and quantify the impact of the nuclear structure.

    ↳ nucl-thhep-phEPJ Web Conf.(2024)·10 citations
48. 48*

    Loop corrections in the separate universe picture

    Laura Iacconi🇬🇧 · David Mulryne🇬🇧 · David Seery🇬🇧

    In inflationary models that produce a spike of power on short scales, back-reaction of small-scale substructure onto large-scale modes is enhanced. We argue that the separate universe framework provides a highly convenient tool to compute loop corrections that quantify this back-reaction. Each loop of interest is characterized by large hierarchies in wavenumber and horizon exit time. The separate universe framework highlights important factorizations involving these hierarchies. We interpret each loop correction in terms of a simple, classical, back-reaction model, and clarify the meaning of the different volume scalings that have been reported in the literature. We argue that significant back-reaction requires both short-scale nonlinearities and long-short couplings that modulate the short-scale power spectrum. In the absence of long-short couplings, only incoherent shot noise-like effects are present, which are volume-suppressed. Dropping the shot noise, back-reaction from a particular scale is controlled by a product of $f_{NL}$-like parameters: an equilateral configuration measuring the nonlinearity of the short-scale modes, and a squeezed configuration measuring the long-short coupling. These may carry important scale dependence controlling the behaviour of the loop in the decoupling limit where the hierarchy of scales becomes large. In single-field models the long-short coupling may be suppressed by this hierarchy, in which case the net back-reaction would be safely suppressed. We illustrate our framework using explicit computations in a 3-phase ultra-slow-roll scenario. Finally, we discuss different choices for the smoothing scale used in the separate universe framework and argue the effect can be absorbed into a renormalization of local operators.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2024)·60 citations
49. 49*

    Testing Graviton Parity and Gaussianity with Planck T-, E- and B-mode Bispectra

    Oliver H. E. Philcox🇺🇸 · Maresuke Shiraishi🇯🇵

    Many inflationary theories predict a non-Gaussian spectrum of primordial tensor perturbations, sourced from non-standard vacuum fluctuations, modified general relativity or new particles such as gauge fields. Several such models also predict a chiral spectrum in which one polarization state dominates. In this work, we place constraints on the non-Gaussianity and parity properties of primordial gravitational waves utilizing the Planck PR4 temperature and polarization dataset. Using recently developed quasi-optimal bispectrum estimators, we compute binned parity-even and parity-odd bispectra for all combinations of CMB T-, E- and B-modes with $2\le \ell <500$, and perform both blind tests, sensitive to arbitrary three-point functions, and targeted analyses of a well-motivated equilateral gravitational wave template (sourced by gauge fields), with amplitude $f_{\mathrm{NL}}^{ttt}$. This is the first time B-modes have been included in primordial non-Gaussianity analyses; they are found to strengthen constraints on the parity-even sector by $\simeq 30\%$ and dominate the parity-odd bounds, without inducing bias. We report no detection of non-Gaussianity (of either parity), with the template amplitude constrained to $f_{\mathrm{NL}}^{ttt}=900\pm 700$ (stable with respect to a number of analysis variations), compared to $1300\pm 1200$ in Planck 2018. The methods applied herein can be reapplied to upcoming CMB datasets such as LiteBIRD, with the inclusion of B-modes poised to dramatically improve future bounds on tensor non-Gaussianity.

    ↳ astro-ph.COgr-qchep-exhep-ph+1PRD(2024)·21 citations
50. 50*

    Stochastic Gravitational Waves from Early Structure Formation

    Nicolas Fernandez🇺🇸 · Joshua W. Foster🇺🇸 · Benjamin Lillard🇺🇸 · Jessie Shelton🇺🇸

    Early matter-dominated eras (EMDEs) are a natural feature arising in many models of the early universe and can generate a stochastic gravitational wave background (SGWB) during the transition from an EMDE to the radiation-dominated universe required by the time of Big Bang Nucleosynthesis. While there are calculations of the SGWB generated in the linear regime, no detailed study has been made of the nonlinear regime. We perform the first comprehensive calculation of GW production in the nonlinear regime, using a hybrid $N$-body and lattice simulation to study GW production from both a metastable matter species and the radiation produced in its decay. We find that nonlinearities significantly enhance GW production up to frequencies at least as large as the inverse light-crossing time of the largest halos that form prior to reheating. The resulting SGWB is within future observational reach for curvature perturbations as small as those probed in the cosmic microwave background, depending on the reheating temperature. Out-of-equilibrium dynamics could further boost the induced SGWB, while a fully relativistic gravitational treatment is required to resolve the spectrum at even higher frequencies.

    ↳ astro-ph.COgr-qchep-phPRL(2024)·42 citations
51. 51*

    Non-trivial thick brane realisations with 3-forms

    Bruno J. Barros🇵🇹 · Jose Beltrán Jiménez🇪🇸

    We explore the construction of four-dimensional thick branes supported by massless 3-forms in a five-dimensional bulk space. The required residual Poincaré symmetry on the brane is realised as a combination of the bulk symmetries and the internal gauge symmetry of the 3-form. We show the presence of a gradient instability for the perturbations orthogonal to the brane when its profile decays slowly in the asymptotic regions. In particular, we ascertain that the prevailing profiles found in the literature are susceptible to such instabilities. We confirm our results by transitioning to the dual formulation in terms of a shift-symmetric scalar. In this formulation, the residual Poincaré group is trivially realised without internal symmetries, and there is a diagonal translational invariance in the fifth dimension reminiscent of the invariance under translations orthogonal to the brane of the dual 3-form. We demonstrate the extension of our results to the cases of de Sitter and Anti de Sitter branes where the gradient instabilities of asymptotically slowly decaying branes persist. Finally, we briefly comment on the construction of thick branes with massive 3-forms and their 1-form duals.

    ↳ gr-qchep-phhep-thJHEP(2024)·6 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.