Tue·Sep 26, 2023Tuesday·September 26, 2023

1. 01*

   The Effect of Multiple Cooling Channels on the Formation of Dark Compact Objects

   Joseph Bramante🇨🇦 · Melissa Diamond🇨🇦 · J. Leo Kim🇨🇦

   A dissipative dark sector can result in the formation of compact objects with masses comparable to stars and planets. In this work, we investigate the formation of such compact objects from a subdominant inelastic dark matter model, and study the resulting distributions of these objects. In particular, we consider cooling from dark Bremsstrahlung and a rapid decay process that occurs after inelastic upscattering. Inelastic transitions introduce an additional radiative processes which can impact the formation of compact objects via multiple cooling channels. We find that having multiple cooling processes changes the mass and abundance of compact objects formed, as compared to a scenario with only one cooling channel. The resulting distribution of these astrophysical compact objects and their properties can be used to further constrain and differentiate between dark sectors.

   hep-phastro-ph.GAJCAP(2024)·14 citations
2. 02*

   Efficient precision simulation of processes with many-jet final states at the LHC

   Enrico Bothmann🇩🇪 · Taylor Childers🇺🇸 · Christian Guetschow🇬🇧 · Stefan Höche🇺🇸 · Paul Hovland🇺🇸 · Joshua Isaacson🇺🇸 · Max Knobbe🇩🇪 · Robert Latham🇺🇸

   We present a scalable technique for the simulation of collider events with multi-jet final states, based on an improved parton-level event file format. The method is implemented for both leading- and next-to-leading order QCD calculations. We perform a comprehensive analysis of the I/O performance and validate our new framework using Higgs-boson plus multi-jet production with up to seven jets. We make the resulting code base available for public use.

   hep-phPRD(2024)·20 citations
3. 03*

   Sterile Neutrino Dark Matter, Matter-Antimatter Separation, and the QCD Phase Transition

   Mikhail Shaposhnikov🇨🇭 · Alexei Yu Smirnov🇩🇪

   The Universe may contain sufficiently small size matter-antimatter domains at temperatures of a few hundred MeV, without violating the success of Big Bang Nucleosynthesis. We demonstrate that this possibility enhances the keV scale sterile neutrino production and may lead to its abundance consistent with the observable energy density of dark matter (DM). We suggest that the separation of matter and antimatter, creating temporarily macroscopic domains occupied by hadronic matter and quark-gluon plasma with an excess of baryons over anti-baryons and vice versa largely exceeding the average baryon and lepton asymmetries of the Universe, may appear because of the first-order QCD phase transition. Although the lattice studies provided a piece of evidence in favour of a smooth crossover between the hadronic and quark-gluon phases at high temperatures and zero chemical potential for baryonic number, we argue that these simulations might not rule out relatively weekly first-order phase transition. We discuss several scenarios of matter-antimatter separation at the QCD phase transition and the production of DM sterile neutrinos in each of them. One of the possibilities requires the presence of lepton asymmetry of the Universe, which can be smaller than that needed for the DM correct abundance in the homogeneous case.

   hep-phastro-ph.COPRD(2024)·7 citations
4. 04*

   Axion-Neutrino Couplings, Late-time Phase Transitions and the Far Infrared Physics

   V.K. Oikonomou🇬🇷

   The far infrared physics is a fascinating topic for theoretical physics, since the foundation of quantum field theory and neutrinos seem to be strongly related with the far infrared physics of our Universe. In this work we shall explore the possibility of a late-time thermal phase transition caused by the axion-neutrino interactions. The axion is assumed to be the misalignment axion which is coupled primordially to a chiral symmetric neutrino. The chiral symmetry is supposed to be broken either spontaneously or explicitly, and two distinct phenomenological models of axion-neutrinos are constructed. The axion behaves as cold dark matter during all its evolution eras, however if we assume that the axion and the neutrino fields interact coherently in a classical way as fields, or as ensembles, then we consider thermal effects in the axion sector, due to the values of operators $\varphi$ for the axion and $\bar{\nu }\nu$ due to the neutrinos. The thermal equilibrium between the two has no effect to the axion effective potential for a wide temperature range. As we show, contrary to the existing literature, the axion never becomes destabilized due to the finite temperature effects, however if axion-Higgs higher order non-renormalizable operators are present in the Lagrangian, the axion potential is destabilized in the temperature range $T\sim 0.1$MeV down to $T\sim 0.01$eV and a first order phase transition takes place. The initial axion vacuum decays to the energetically more favorable axion vacuum, and the latter decays to the Higgs vacuum which is more preferable. This late-time phase transition might take place in the redshift range $z\sim 385-37$ and thus it may cause density fluctuations in the post-recombination era.

   hep-phastro-ph.COgr-qchep-thPhys.Dark Univ.(2023)·3 citations
5. 05*

   Bubble nucleation in the two-flavor quark-meson model

   Junrong Wang🇨🇳 · Ziwan Yu🇨🇳 · Hong Mao🇨🇳

   We investigate the dynamics of a first-order quark-hadron transition via homogeneous thermal nucleation in the two-flavor quark-meson model. The contribution of the fermionic vacuum loop in the effective thermodynamics potential and phase diagram together with the location of critical end point (CEP) have been obtained in the temperature and chemical potential plane. For a weak and strong first-order phase transition, by taking the temperature as a variable, the critical bubble profiles, the evolutions of the surface tension and the saddle-point action in the presence of a nucleation bubble are numerically calculated in detail when fixing the chemical potentials at $\mu =306\mathrm{MeV}$ and $\mu =309\mathrm{MeV}$. Our results show that the system could be trapped in the metastable state for a long time as long as the temperature is between the metastable region characterized by the up and low spinodal lines. Moreover, the surface tension at criticality will rise up to about $4MeV/f{\mathrm{m}}^2$ when the chemical potential is very high. Such a small value of the surface tension would favor a mixed phase in the cores of compact stars and may have an important implication in astrophysics.

   hep-phnucl-thCPC(2024)·7 citations
6. 06*

   Fully and Doubly-heavy four-quarks within QCD Laplace sum rule

   R. M. Albuquerque🇧🇷 · S. Narison🇫🇷 · A. Rabemananjara🇲🇬 · D. Rabetiarivony🇲🇬

   We present a review of our results for the masses and couplings of the scalar fully heavy four-quarks and $T_{QQ\bar{q}{\bar{q}}^{\prime }}(J^P=0^{\pm },1^{\pm })$ tetraquarks states from QCD Laplace sum rule (LSR), their ratios $\mathcal{R}$ and double ratio of sum rules (DRSR) within stability criteria and including Factorized Next-to-Leading Order (FNLO) Perturbative (PT) corrections. As the Operator Product Expansion (OPE) usually converges for $d⩽6-8$, we evaluated the QCD spectral functions at Lowest Order of PT QCD and up to $⟨G^3⟩$. Our results for the $0^{++}$ fully heavy four-quark states may explain the LHCb broad structure around (6.2-6.7)GeV which can be due to $\overline{{\eta }_c}{\eta }_c,\overline{{\chi }_{c1}}{\chi }_{c1}$ and $\overline{J/\psi }J/\psi$ molecules or/and their analogue $S_c{S}_c,A_c{A}_c$ and $V_c{V}_c$ tetraquarks. The peak at (6.8-6.9)GeV can be identified to the $\overline{{\chi }_{c0}}{\chi }_{c0}$ molecule or/and the $P_c{P}_c$ tetraquark state. Then, combining $\mathcal{R}$ and DRSR we focus on the analysis of the four-quark nature of $T_{cc\bar{q}{\bar{q}}^{\prime }}$ $1^{\pm }$ and $0^{\pm }$ states. We show that combining $\mathcal{R}$ and DRSR can provide more precise results: $M_{T_{cc}^{1^{+}}}=3886(6)$MeV and $M_{T_{cc}^{0^{+}}}=3883(3)$MeV. From our estimates of the masses of the Pseudoscalar and Vector $T_{cc\bar{q}{\bar{q}}^{\prime }}$ states, we observe that the interpolating currents lead to two classes: Class H (Heavy) states with masses around 6GeV and Class L (Light) states around (3.8-4.4)GeV where the pseudoscalar (resp. all vector states) are below the $\overline{D}{D}_0,overline{D}_s{D}_{s0}$ (resp. $\overline{D}{D}_1,{\overline{D}}_s{D}_{s1}$) open charm thresholds. Finally, we extend the whole study to the bottom sector and confront our results with the ones from different LSR predictions and some other approaches in the literature.

   hep-ph1 citation
7. 07*

   CDF II W-mass anomaly and SO(10) GUT

   Purushottam Sahu🇮🇳 · Hiranmaya Mishra🇮🇳 · Prasanta K. Panigrahi🇮🇳 · Sudhanwa Patra🇮🇳 · Utpal Sarkar🇮🇳

   The W-mass anomaly has yet to be established, but a huge proliferation of articles on the subject established the rich potential of such event. We investigate the SO(10) GUT constraints from the recently reported W-mass anomaly. We consider both Supersymmetric (SUSY) and non-supersymmetric (non-SUSY) grand unified theories by studying renormalization group equations (RGEs) for gauge coupling unification and their predictions on proton decay. In the non-SUSY models, single-stage unification is possible if one include a light (around TeV) real triplet Higgs scalar. However, these models predict speedy proton decay, inconsistent with the present experimental bound on the proton decay. This situation may be improved by including newer scalars and new intermediate-mass scales, which are present in the $SO(10)$ GUTs. The standard model is extended to a left-right symmetric model (LR), and the scale of LR breaking naturally introduces the intermediate scale in the model. A single-stage unification is possible even without including any triplet Higgs scalar in a minimal supersymmetric standard model.

   hep-ph0 citations
8. 08*

   A New Model for Jet Energy Loss in Heavy Ion Collisions

   Alexander Lind🇫🇷 · Iurii Karpenko🇫🇷 · Martin Rohrmoser🇵🇱 · Joerg Aichelin🇫🇷 · Pol Gossiaux🇫🇷 · Klaus Werner🇫🇷

   We present a new model for jet quenching from coherent radiation in a brick medium. The jet energy loss is simulated as a perturbative final-state vacuum parton shower followed by a medium-induced shower originating from elastic and radiative collisions with the medium constituents. Coherency is achieved by starting with trial gluons that act as field dressing of the initial jet parton. These are formed according to a Gunion-Bertsch seed. The QCD version of the LPM effect is attained by increasing the phase of the trial gluons through elastic scatterings with the medium. Above a phase threshold, the trial gluons will be realised and can produce coherent radiation themselves. The model has been implemented in a Monte Carlo code and has been validated by successfully reproducing the BDMPS-Z prediction for the energy spectrum. The realistic case with minimal assumptions are also produced and shown. In particular, we show the influence of various parameters on the energy spectrum and transverse momentum distribution, such as the in-medium quark masses, the energy transfer in the recoil process, and the phase accumulation criteria, especially for low and intermediate energy gluons. Future studies will allow for the interface with full simulations of the quark-gluon-plasma with hydrodynamic evolution, such as vHLLE, along with subsequent hadronisation of the jet partons in order to produce realistic distributions that can be directly compared to LHC and RHIC data.

   hep-phnucl-thPoS(2024)·0 citations
9. 09*

   Dynamics in fractal spaces

   Eugenio Megias🇪🇸 · Alireza K. Golmankhaneh🇮🇷 · Airton Deppman🇧🇷

   This study investigates the interconnections between the traditional Fokker-Planck Equation (FPE) and its fractal counterpart (FFPE), utilizing fractal derivatives. By examining the continuous approximation of fractal derivatives in the FPE, it derives the Plastino-Plastino Equation (PPE), which is commonly associated with Tsallis Statistics. This work deduces the connections between the entropic index and the geometric quantities related to the fractal dimension. Furthermore, it analyzes the implications of these relationships on the dynamics of systems in fractal spaces. In order to assess the effectiveness of both equations, numerical solutions are compared within the context of complex systems dynamics, specifically examining the behaviours of quark-gluon plasma (QGP). The FFPE provides an appropriate description of the dynamics of fractal systems by accounting for the fractal nature of the momentum space, exhibiting distinct behaviours compared to the traditional FPE due to the system's fractal nature. The findings indicate that the fractal equation and its continuous approximation yield similar results in studying dynamics, thereby allowing for interchangeability based on the specific problem at hand.

   hep-phhep-thstat.MEPLB(2024)·6 citations
10. 10*

    On quantum spreading of a localized stationary flow of high energy particles

    N. F. Shul'ga🇺🇦 · S. N. Shulga🇺🇦

    The study addresses the quantum spreading of a localized stationary flow of high energy particles. Results demonstrate that as particle energy increases, the spreading speed of the particle wave packet diminishes rapidly. Concurrently, increasing the energies stabilizes the initially localized packet, preserving its transverse form in a vacuum over extended distances. This allows substantial simplifications when using various approximate methods to calculate the wave function in an external field.

    hep-ph0 citations
11. 11*

    Strong decays of low-lying $D$-wave ${\Xi }_b/{\Xi }_b^{\prime }$ baryons with QPC model

    Yu-Hui Zhou🇨🇳 · Wen-Jia Wang🇨🇳 · Li-Ye Xiao🇨🇳 · Xian-Hui Zhong🇨🇳

    For further decoding the inner structure of the two excited ${\Xi }_b$ states observed by LHCb, we perform a systematical study of the strong decays of the low-lying $1D$-wave ${\Xi }_b$ and ${\Xi }_b^{\prime }$ excitations using the quark pair creation model within the $j-j$ coupling scheme. Combining with the measured masses and decay properties of ${\Xi }_b(6327{)}^0$ and ${\Xi }_b(6327{)}^0$, the two excited states can be explained as $1D$ $\lambda$-mode ${\Xi }_b$ states ${\Xi }_b|J^P={\frac{3}{2}}^{+},2{⟩}_{\lambda \lambda }$ and ${\Xi }_b|J^P={\frac{5}{2}}^{+},2{⟩}_{\lambda \lambda }$, respectively. If such a view were correct, ${\Xi }_b^{\prime }\pi$ and ${\Xi }_b^{\prime \ast }\pi$ could be another interesting channels for experimental exploring of the ${\Xi }_b(6327{)}^0$ and ${\Xi }_b(6327{)}^0$, respectively. Those calculations are good consistent with the results within the chiral quark model. In addition, for the other missing $1D$-wave ${\Xi }_b$ and ${\Xi }_b^{\prime }$ excitations, our predictions indicate that:(i) the two $\rho$-mode $1D$ ${\Xi }_b$ states are likely to be moderate states with a width of $\Gamma \sim 50$ MeV. The $J^P=3/2^{+}$ state dominantly decays into ${\Sigma }_{b}K$ and ${\Xi }_b^{\prime }\pi$, while the $J^P=5/2^{+}$ state decays primarily through ${\Sigma }_b^{\ast }K$ and ${\Xi }_b^{\prime \ast }\pi$. (ii) The $\lambda$-mode $1D$ ${\Xi }_b^{\prime }$ states may be moderate states with a widths of about several to dozens of MeV. Most of the $\lambda$-mode $1D$ ${\Xi }_b^{\prime }$ states mainly decay into the $1P$-wave bottomed baryon via the pionic decay processes. Meanwhile, several $\lambda$-mode $1D$ ${\Xi }_b^{\prime }$ states have significant decay rates into $\Lambda B$. (iii) While, the $\rho$-mode $1D$ ${\Xi }_b^{\prime }$ states are predicted to be very broad states with a width of about several hundreds MeV. It will be a great challenge to explore the $\rho$-mode $1D$ ${\Xi }_b^{\prime }$ states in experiments for their broad widths.

    hep-phPRD(2023)·6 citations
12. 12*

    Texture zeros realization in a three-loop radiative neutrino mass model from modular $A_4$ symmetry

    Takaaki Nomura🇨🇳 · Hiroshi Okada🇯🇵 · Hajime Otsuka🇯🇵

    We derive verifiable two-zero textures in the framework of a three-loop induced neutrino mass model applying a modular $A_4$ symmetry for the lepton sector. Interestingly, the neutrino mass structure is determined by assignments of the right-handed charged-lepton particles only. We show all the possible texture patterns and demonstrate their analytical and numerical analyses. Finally, we mention a possibility of detection for doubly-charged boson via colliders that decays into specific modes due to the flavor symmetry.

    hep-phNPB(2024)·24 citations
13. 13*

    Global analysis and LHC study of a vector-like extension of the Standard Model with extra scalars

    A. E. Cárcamo Hernández🇨🇱 · Kamila Kowalska🇵🇱 · Huchan Lee🇵🇱 · Daniele Rizzo🇵🇱

    We perform a global analysis of a vector-like extension of the Standard Model, which also features additional doublet and singlet scalars. The usual Yukawa interactions are forbidden in this setup by an extra U(1) global symmetry and the masses of the second and third family quarks and leptons are generated via the mixing with the vector-like sector. We identify three best-fit benchmark scenarios which satisfy the constraints imposed by the stability of the scalar potential, the perturbativity of the coupling constants, the measurement of the muon anomalous magnetic moment and the non-observation of the flavor violating tau decays. We show that dominant contributions to the muon $(g-2)$ originate in this model from the charged Higgs/neutral lepton one-loop diagrams, thus correcting an inaccurate statement than can be found in the literature. We also perform a detailed LHC analysis of the benchmark scenarios. We investigate the experimental constraints stemming from direct searches for vector-like quarks, vector-like leptons and exotic scalars. While we show that the model is not currently tested by any collider experiment, we point out that decays of a heavy Higgs boson into two tau leptons may offer a smoking gun signature for the model verification in upcoming runs at the LHC.

    hep-phPRD(2024)·15 citations
14. 14*

    Unitarity Bounds and Basis Transformations in SMEFT: An Analysis of Warsaw and SILH Bases

    Qing-Hong Cao🇨🇳 · Yandong Liu🇨🇳 · Shu-Run Yuan🇨🇳

    The equivalence between the Warsaw and SILH bases in Standard Model Effective Field Theory is well established, with transformation rules connecting the two via equations of motion and field redefinitions. This study presents an explicit calculation of the analytical unitarity bounds-defined as the marginal limit of the parameter space-for dimension-six operators within both the Warsaw and SILH bases. We employ a coupled channel analysis to scrutinize scattering processes involving vector bosons and fermions. We conduct a comprehensive investigation into the transformation of unitarity bounds under changes in the operator basis. Our findings demonstrate that the transformation rules, as implicated by the equivalence theorem, can be directly applied to convert unitarity bounds from one basis to another, provided that the operators involved in the transformation rules do not belong to the same subset defined by a block in the coupled channel matrix.

    hep-ph2 citations
15. 15*

    HyperTrack: Neural Combinatorics for High Energy Physics

    Mikael Mieskolainen🇬🇧

    Combinatorial inverse problems in high energy physics span enormous algorithmic challenges. This work presents a new deep learning driven clustering algorithm that utilizes a space-time non-local trainable graph constructor, a graph neural network, and a set transformer. The model is trained with loss functions at the graph node, edge and object level, including contrastive learning and meta-supervision. The algorithm can be applied to problems such as charged particle tracking, calorimetry, pile-up discrimination, jet physics, and beyond. We showcase the effectiveness of this cutting-edge AI approach through particle tracking simulations. The code is available online.

    hep-phcs.LGhep-exEPJ Web Conf.(2024)·2 citations
16. 16*

    Confinement Slingshot and Gravitational Waves

    Maximilian Bachmaier🇩🇪 · Gia Dvali🇩🇪 · Juan Sebastián Valbuena-Bermúdez🇩🇪 · Michael Zantedeschi🇨🇳

    In this paper, we introduce and numerically simulate a quantum field theoretic phenomenon called the gauge ``slingshot" effect and study its production of gravitational waves. The effect occurs when a source, such as a magnetic monopole or a quark, crosses the boundary between the Coulomb and confining phases. The corresponding gauge field of the source, either electric or magnetic, gets confined into a flux tube stretching in the form of a string (cosmic or a QCD type) that attaches the source to the domain wall separating the two phases. The string tension accelerates the source towards the wall as sort of a slingshot. The slingshot phenomenon is also exhibited by various sources of other co-dimensionality, such as cosmic strings confined by domain walls or vortices confined by $Z_2$ strings. Apart from the field-theoretic value, the slingshot effect has important cosmological implications, as it provides a distinct source for gravitational waves. The effect is expected to be generic in various extensions of the standard model such as grand unification.

    hep-phhep-thPRD(2024)·14 citations
17. 17*

    An alternative evaluation of the leading-order hadronic contribution to the muon g-2 with MUonE

    Fedor Ignatov🇬🇧 · Riccardo Nunzio Pilato🇬🇧 · Thomas Teubner🇬🇧 · Graziano Venanzoni🇬🇧

    We propose an alternative method to extract the leading-order hadronic contribution to the muon g-2, $a_{\mu }^{\text{HLO}}$, with the MUonE experiment. In contrast to the traditional method based on the integral of the hadronic contribution to the running of the effective fine-structure constant $\Delta {\alpha }_{had}$ in the space-like region, our approach relies on the computation of the derivatives of $\Delta {\alpha }_{had}(t)$ at zero squared momentum transfer $t$. We show that this approach allows to extract $\sim 99\%$ of the total value of $a_{\mu }^{\text{HLO}}$ from the MUonE data, while the remaining $\sim 1\%$ can be computed combining perturbative QCD and data on $e^{+}{e}^{-}$ annihilation to hadrons. This leads to a competitive evaluation of $a_{\mu }^{\text{HLO}}$ which is robust against the parameterization used to model $\Delta {\alpha }_{had}(t)$ in the MUonE kinematic region, thanks to the analyticity properties of $\Delta {\alpha }_{had}(t)$, which can be expanded as a polynomial at $t\sim 0$.

    hep-phhep-exPLB(2024)·17 citations
18. 18*

    Analytic results for massive $2\to 2$ processes

    Matthias Steinhauser🇩🇪

    We discuss recent (semi) analytic results for $2\to 2$ processes with massive internal and external particles in various regions of phase space. In the physical applications we restrict ourselves to $gg\to HH$.

    hep-phPoS(2024)·0 citations
19. 19*

    Explaining PTA Data with Inflationary GWs in a PBH-Dominated Universe

    Satyabrata Datta🇮🇳

    We show that an ultralight primordial black hole (PBH) dominated phase makes blue-tilted inflationary gravitational waves (BGW) compatible with the recent detection of an nHz stochastic GW background by pulsar-timing arrays (PTAs), for high reheating temperatures. This PBH-dominated phase suppresses the BGW spectrum via entropy dilution and generates a new GW spectrum from PBH density fluctuations. This combined spectrum is detectable at ongoing and planned near-future GW detectors and exhibits a unique shape with a low-frequency peak explaining PTA data, a mid-range dip, and a sharp peak followed by a third peak at high-frequency. This distinctive shape sets it apart from spectra generated by other matter dominations or exotic physics. Therefore, while important for studying GWs in the nHz range, the recent PTA result also sets the stage for testing and constraining various well-studied mechanisms following a PBH domination, using low-frequency measurements and correlated observations of unique high-frequency GW spectral features.

    hep-phastro-ph.COJCAP(2024)·21 citations
20. 20*

    Gravitational production of matter and radiation during reheating

    Simon Cléry🇫🇷

    I present the production of matter and radiation during reheating after inflation, considering only gravitational interactions between the inflaton background and the other sectors. Processes considered are the following: i) the exchange of a graviton, $h_{\mu \nu }$, involved in the scattering of the inflaton or particles in the newly created radiation bath; ii) scattering of the inflaton background and particles in the radiation bath including the effects of non-minimal couplings to curvature of the Higgs boson and the inflaton. Requiring the existence of heavy right-handed neutrinos (RHN), I show that a minimal scenario utilizing only these "gravitational portals" is able to generate simultaneously the observed relic density of Dark Matter (DM), the baryon asymmetry through leptogenesis, as well as a sufficiently hot thermal bath after inflation, for generic models of large field inflation.

    hep-phastro-ph.COhep-th0 citations
21. 21*

    Rare tau decays via exchange of on-shell almost degenerate Majorana neutrinos, ${\tau }^{\mp }\to {\pi }^{\mp }{N}_j\to {\pi }^{\mp }{\mu }^{\mp }{\pi }^{\pm }$ and ${\tau }^{\mp }\to {\pi }^{\mp }{N}_j\to {\pi }^{\mp }{\mu }^{\pm }{\pi }^{\mp }$

    Gorazd Cvetic🇨🇱 · C.S.Kim🇰🇷

    We investigate rare decays of tau leptons that occur via exchange of heavy on-shell neutrinos $N_j$ ($j=1,2$). These neutrinos can be either Dirac or Majorana, and are considered to be almost degenerate in mass. The decays can thus be either lepton number conserving (LNC), ${\tau }^{\mp }\to {\pi }^{\mp }{N}_j\to {\pi }^{\mp }{\mu }^{\mp }{\pi }^{\pm }$, or lepton number violating (LNV), ${\tau }^{\mp }\to {\pi }^{\mp }{N}_j\to {\pi }^{\mp }{\mu }^{\pm }{\pi }^{\mp }$. If neutrinos are Dirac, only LNC decays are possible. If they are Majorana, both LNC and LNV are possible. We derive the corresponding expressions for the effective decay widths ${\Gamma }_{\mathrm{eff},\mp }^{(\mathrm{X})}$ (X=LNC, LNV) of these rare decays, where we account for $N_1$-$N_2$ overlap and oscillation effects and for the finite detector length effects. We then numerically evaluate these decay widths as well as the related CP violation asymmetry width $\Delta {\Gamma }_{\mathrm{CP}}^{(\mathrm{X})}=({\Gamma }_{\mathrm{eff},-}^{(\mathrm{X})}-{\Gamma }_{\mathrm{eff},+}^{(\mathrm{X})})$. We conclude that for certain, presently allowed, ranges of the heavy-light neutrino mixing parameters, such decays and asymmetries could be observed in Belle II experiment.

    hep-phJHEP(2024)·3 citations
22. 22*

    Future Challenges For Event Generators

    Davide Napoletano🇮🇹

    In this talk I present a personal perspective on what the current and future challenges are for Monte Carlo event generators. I focus in particular on those aspects of Monte Carlo event generators that have not, historically, received the same scrutiny and level of advancements which will be mandatory in future, cleaner and more precise experimental set-ups than current day LHC.

    hep-ph0 citations
23. 23*

    Binary Discrimination Through Next-to-Leading Order

    Andrew J. Larkoski🇺🇸

    Binary discrimination between well-defined signal and background datasets is a problem of fundamental importance in particle physics. With detailed event simulation and the advent of extensive deep learning tools, identification of the likelihood ratio has typically been reserved as a computational problem. However, this approach can obscure overtraining or excessive sensitivity to tuned features of the simulation that may not be well-defined theoretically. Here, we present the first analysis of binary discrimination for signal and background distributions for which their likelihood ratio is infrared and collinear safe, and can therefore be calculated order-by-order in perturbation theory. We present explicit, general formulas for receiver operator characteristic curves and the area under it through next-to-leading order. As a demonstration of this formalism, we apply it to discrimination of highly-boosted Higgs decays from gluon splitting to bottom quarks. Effects at next-to-leading order are first sensitive to the flow of color in the jet and significantly modify discrimination performance at leading-order. In the limit of infinite boost, these events can be perfectly discriminated because only the gluon will radiate at finite angles from the bottom quarks, and we find that large effects persist at energies accessible at the Large Hadron Collider. Next-to-leading order is therefore required to qualitatively understand results using machine-learning methods.

    hep-phhep-exJHEP(2024)·5 citations
24. 24*

    Glimmers from the Axiverse

    Naomi Gendler🇺🇸 · David J. E. Marsh🇬🇧 · Liam McAllister🇺🇸 · Jakob Moritz🇺🇸

    We study axion-photon couplings in compactifications of type IIB string theory. We find that these couplings are systematically suppressed compared to the inverse axion periodicity, as a result of two effects. First, couplings to the QED theta angle are suppressed for axion mass eigenstates that are light compared to the mass scale set by stringy instantons on the cycle supporting QED. Second, in compactifications with many axions the intersection matrix is sparse, making kinetic mixing weak. We study the resulting phenomenology in an ensemble of $200,000$ toy models constructed from the Kreuzer-Skarke database up to the maximum Hodge number $h^{1,1}=491$. We examine freeze-in production and decay of thermal axions, birefringence of the cosmic microwave background, X-ray spectrum oscillations, and constraints on the QCD axion from supernovae. We conclude that compactifications in this corner of the landscape involve many invisible axions, as well as a handful that may be detectable via photon couplings.

    ↳ hep-thastro-ph.COhep-phJCAP(2024)·105 citations
25. 25*

    Sphaleron rate from lattice QCD

    Claudio Bonanno🇪🇸 · Francesco D'Angelo🇮🇹 · Massimo D'Elia🇮🇹 · Lorenzo Maio🇮🇹 · Manuel Naviglio🇮🇹

    We compute the sphaleron rate on the lattice from the inversion of the Euclidean time correlators of the topological charge density, performing also controlled continuum and zero-smoothing extrapolations. The correlator inversion is performed by means of a recently-proposed modification of the Backus-Gilbert method.

    ↳ hep-lathep-phNucl.Part.Phys.Proc.(2024)·4 citations
26. 26*

    Physics Potential of a Few Kiloton Scale Neutrino Detector at a Deep Underground Lab in Korea

    Seon-Hee Seo🇰🇷 · Jose Alonso🇺🇸 · Pouya Bakhti🇰🇷 · Janet Conrad🇺🇸 · Steve Dye🇺🇸 · Doojin Kim🇺🇸 · Jost Migenda🇬🇧 · Marco Pallavicini🇮🇹 · Jong-Chul Park🇰🇷 · Meshkat Rajaee🇰🇷 · Mike Shaevitz🇺🇸 · Seodong Shin🇰🇷 and 5 other authors

    The demand for underground labs for neutrino and rare event search experiments has been increasing over the last few decades. Yemilab, constructed in October 2022, is the first deep ($\sim$1~km) underground lab dedicated to science in Korea, where a large cylindrical cavern (D: 20~m, H: 20~m) was excavated in addition to the main caverns and halls. The large cavern could be utilized for a low background neutrino experiment by a liquid scintillator-based detector (LSC) where a 2.26 kiloton LS target would be filled. It's timely to have such a large but ultra-pure LS detector after the shutdown of the Borexino experiment so that solar neutrinos can be measured much more precisely. Interesting BSM physics searches can be also pursued with this detector when it's combined with an electron linac, a proton cyclotron (IsoDAR source), or a radioactive source. This article discusses the concept of a candidate detector and the physics potential of a large liquid scintillator detector.

    ↳ hep-exhep-ph9 citations
27. 27*

    Strangelets formation in high energy heavy-ion collisions

    Huai-Min Chen🇨🇳 · Cheng-Jun Xia🇨🇳 · Guang-Xiong Peng🇨🇳

    The properties of phase diagram of strange quark matter in equilibrium with hadronic matter at finite temperature are studied, where the quark phase and hadron phase are treated by baryon density-dependent quark mass model and hadron resonance gas model with hard core repulsion factor, respectively. The thermodynamic conditions for the formation of metastable strange quark droplets ("strangelets") in relativistic nuclear collisions are discussed. We obtained a rich structure of the phase diagram at finite temperature, and study the dynamical trajectories of an expanding strange fireball. Our results indicate that the strangeness fraction fs, perturbation parameter C, and confinement parameter D have strong influence on the properties of phase diagram and the formation of strangelets. Consider the isentropic expansion process, we found that the initial entropy per baryon is less than or equal to 5, which gives a large probability for the formation of strangelets. Furthermore, a sufficiently large strangeness fraction fs and one-gluon-exchange interaction and sufficiently small confinement interaction create possibilities for the formation of strangelets. On the contrary, the fireball will always complete the hadronization process when fs=0 or C>=0 or D^{1/2}>=170 MeV.

    ↳ nucl-thhep-phPRD(2024)·8 citations
28. 28*

    End of the World Perspective to BCFT

    Kyung Kiu Kim🇰🇷 · Sejin Kim🇰🇷 · Jung Hun Lee🇰🇷 · Chanyong Park🇰🇷 · Yunseok Seo🇰🇷

    In this work, we study the end-of-the-world (EOW) branes anchored to the boundaries of BCFT${}_2$ dual to the BTZ black hole. First, we explore the thermodynamics of the boundary system consisting of the conformal boundary and two EOW branes. This thermodynamics is extended by the tension appearing as the effective cosmological constant of JT black holes on the EOW branes. The tension contribution is identified with the shadow entropy equivalent to the boundary entropy of the BCFT${}_2$. The thermodynamics of the JT black holes and the bulk of BCFT${}_2$ can be combined into a novel grafted thermodynamics based on the first law. Second, we focus on the observer's view of the EOW branes by lowering the temperature. We show that the EOW branes generate a scale called ``reefs" inside the horizon. This scale also appears in the grafted thermodynamics. At high temperatures, observers on the EOW branes see their respective event horizons. The reef starts to grow relatively to the horizon size at the temperature, $T_{grow}$. As the temperature cools down the reef area fills the entire interior of the JT black holes at the temperature $T_{out}$. Then, the observers recognize their horizons disappear and see the large density of the energy flux. At this temperature, the two JT regions become causally connected. This connected spacetime has two asymptotic $Ad{S}_2$ boundaries with a conformal matter. Also, we comment on the grafted thermodynamics to higher dimensions in Appendix B.

    ↳ hep-thhep-phEPJC(2024)·6 citations
29. 29*

    Constraining the Charge of a Black Hole with Electromagnetic Radiation from a Black Hole-Neutron Star System

    Hao-Yu Yuan🇨🇳 · Hou-Jun Lü🇨🇳 · Jared Rice🇺🇸 · En-Wei Liang🇨🇳

    Black hole-neutron star (BH-NS) mergers are expected to emit gravitational-wave (GW) and electromagnetic (EM) counterparts when the NS is tidally disrupted or plunges into the BH. Recently, GW 200105 and GW200115 were claimed as originating in BH-NS mergers, even GW 200105 remains in debate. Several optical source candidates are reported to possible associate with the two GW events, but not confirmed yet. In this work, we assume that the BH is charged (the NS is naturally charged) and try to constrain the charge of the BH by using the possible associated EM emission from the charged BH and NS system working in the inspiral regime. We adopt electric and magnetic dipole radiations for the binaries which power a Poynting-flux-dominated outflow to accelerate electrons. Then, it produces the observed EM radiation via synchrotron radiation. We find that the conversion efficiency in the X-ray band is much higher than that of the ultraviolet (UV), near-infrared, and radio bands. The estimated maximum charge-to-mass ratio (the charge for unit mass) of the BH is $1.12\times 10^{-6}$ and $1.53\times 10^{-6}$ esu for the binary systems of GW200105 and GW200115, respectively, if magnetic field strength $B_p\lesssim 10^{16}$ G and period $P>1$ ms for the NS spin.

    ↳ astro-ph.HEgr-qchep-phPRD(2023)·7 citations
30. 30*

    Observational constraints on interactions between dark energy and dark matter with momentum and energy transfers

    Xiaolin Liu🇨🇳 · Shinji Tsujikawa🇯🇵 · Kiyotomo Ichiki🇯🇵

    We place observational constraints on a dark energy (DE) model in which a quintessence scalar field $\varphi$ is coupled to dark matter (DM) through momentum and energy exchanges.The momentum transfer is weighed by an interaction between the field derivative and DM four velocity with a coupling constant $\beta$, whereas the energy exchange is characterized by an exponential scalar-field coupling to the DM density with a coupling constant $Q$. A positive coupling $\beta$ leads to the suppression for the growth of DM density perturbations at low redshifts, whose property offers a possibility for resolving the ${\sigma }_8$ tension problem. A negative coupling $Q$ gives rise to a $\varphi$-matter-dominated epoch, whose presence can reduce the sound horizon around the Cosmic Microwave Background (CMB) decoupling epoch. Using the data of Planck 2018, 12-th Sloan Digital Sky Survey, Phantheon supernovae samples, and 1-year dark energy survey, we find that the two couplings are constrained to be $\beta =0.332_{-0.237}^{+1.246}$ and $Q=-0.0312_{-0.0085}^{+0.0312}$ at 68\,\% confidence level (CL). Thus, there is an interesting observational signature of the momentum exchange ($\beta \ne 0$) between DE and DM, with a peak of the probability distribution of the energy transfer coupling at $Q<0$.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2024)·16 citations
31. 31*

    Scalar and tensor charmonium resonances in coupled-channel scattering from QCD

    David J. Wilson🇬🇧 · Christopher E. Thomas🇬🇧 · Jozef J. Dudek🇺🇸 · Robert G. Edwards🇺🇸

    We determine $J^{PC}=0^{++}$ and $2^{++}$ hadron-hadron scattering amplitudes in the charmonium energy region up to 4100 MeV using lattice QCD, a first-principles approach to QCD. Working at $m_{\pi }\approx 391$ MeV, more than 200 finite-volume energy levels are computed and these are used in extensions of the Lüscher formalism to determine infinite-volume coupled-channel scattering amplitudes. We find that this energy region contains a single ${\chi }_{c0}$ and a single ${\chi }_{c2}$ resonance. Both are found as pole singularities on the closest unphysical Riemann sheet, just below 4000 MeV with widths around 70 MeV. The largest couplings are to kinematically-closed $D^{\ast }{\bar{D}}^{\ast }$ channels in $S$-wave, and couplings to several decay channels consisting of pairs of open-charm mesons are found to be large and significant in both cases. Above the ground state ${\chi }_{c0}$, no other scalar bound-states or near-$D\bar{D}$ threshold resonances are found, in contrast to several theoretical and experimental studies.

    ↳ hep-lathep-phPRL(2024)·32 citations
32. 32*

    Charmonium ${\chi }_{c0}$ and ${\chi }_{c2}$ resonances in coupled-channel scattering from lattice QCD

    David J. Wilson🇬🇧 · Christopher E. Thomas🇬🇧 · Jozef J. Dudek🇺🇸 · Robert G. Edwards🇺🇸

    In order to explore the spectrum of hidden-charm scalar and tensor resonances, we study meson-meson scattering with $J^{PC}=0^{++},2^{++}$ in the charmonium energy region using lattice QCD. Employing a light-quark mass corresponding to $m_{\pi }\approx 391$ MeV, we determine coupled-channel scattering amplitudes up to around 4100 MeV considering all kinematically relevant channels consisting of a pair of open-charm mesons or a charmonium meson with a light meson. A single isolated scalar resonance near 4000 MeV is found with large couplings to $D\bar{D}$, $D_s{\bar{D}}_s$ and the kinematically closed $D^{\ast }{\bar{D}}^{\ast }$ channel. A single tensor resonance at a similar mass couples strongly to $D\bar{D}$, $D{\bar{D}}^{\ast }$ and $D^{\ast }{\bar{D}}^{\ast }$. We compare the extracted resonances to contemporary experimental candidate states, previous lattice results and theoretical modeling. In contrast to several other studies, we do not find any significant feature in the scalar amplitudes between the ground state ${\chi }_{c0}(1P)$ and the resonance found around 4000 MeV.

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

    Hybrid Strangeon Stars

    Chen Zhang🇨🇳 · Yong Gao🇨🇳 · Cheng-Jun Xia🇨🇳 · Renxin Xu🇨🇳

    It was conjectured that the basic units of the ground state of bulk strong matter may be strange-clusters called strangeons, and they can form self-bound strangeon stars that are highly compact. Strangeon stars can develop a strange quark matter (SQM) core at high densities, particularly in the color-flavor-locking phase, yielding a branch of hybrid strangeon stars. We explore the stellar structure and astrophysical implications of hybrid strangeon stars. We find that hybrid strangeon stars can meet various astrophysical constraints on pulsar masses, radii, and tidal deformabilities. Finally, we show that the strangeon-SQM mixed phase is not preferred if the charge-neutrality condition is imposed at the strangeon-SQM transition region.

    ↳ nucl-thastro-ph.HEgr-qchep-phPRD(2023)·19 citations
34. 34*

    Hadronic physics from a Wilson fermion mixed-action approach: Charm quark mass and $D_{(s)}$ meson decay constants

    Andrea Bussone🇩🇪 · Alessandro Conigli🇪🇸 · Julien Frison🇩🇪 · Gregorio Herdoíza🇪🇸 · Carlos Pena🇪🇸 · David Preti🇮🇹 · Alejandro Sáez🇪🇸 · Javier Ugarrio🇪🇸

    We present our first set of results for charm physics, using the mixed-action setup introduced in a companion paper. Maximally twisted Wilson valence fermions are used on a sea of non-perturbatively $O(a)$-improved Wilson fermions, made up by CLS $N_{\mathrm{f}}=2+1$ ensembles. Our charm-sector observables are free from $O(a{m}_c)$ discretisation effects, without need of tuning any improvement coefficient, and show continuum-limit scaling properties consistent with leading cutoff effects of $O(a^2)$. We consider a subset of CLS ensembles -- including four values of the lattice spacing and pion masses down to 200 MeV -- allowing to take the continuum limit and extrapolate to the physical pion mass. A number of techniques are incorporated in the analysis in order to estimate the systematic uncertainties of our results for the charm quark mass and the $D_{(s)}$-meson decay constants. This first study of observables in the charm sector, where the emphasis has been on the control of the methodology, demonstrates the potential of our setup to achieve high-precision results.

    ↳ hep-lathep-phEPJC(2024)·21 citations
35. 35*

    Universal Gravitational Waves from Interacting and Clustered Solitons

    Kaloian D. Lozanov🇯🇵 · Misao Sasaki🇯🇵 · Volodymyr Takhistov🇯🇵

    Causal soliton formation (e.g. oscillons, Q-balls) in the primordial Universe is expected to give rise to a universal gravitational wave (GW) background, at frequencies smaller than scales of nonlinearity. We show that modifications of the soliton density field, driven by soliton interactions or initial conditions, can significantly enhance universal GWs. Gravitational clustering of solitons naturally leads to generation of correlations in the large-scale soliton density field. As we demonstrate for axion-like particle (ALP) oscillons, the growing power spectrum amplifies universal GW signals, opening new avenues for probing the physics of the early Universe with upcoming GW experiments. Our results are applicable to variety of scenarios, such as solitons interacting through a long range Yukawa-like fifth force.

    ↳ astro-ph.COgr-qchep-phPLB(2024)·31 citations
36. 36*

    Chiral Meissner effect in time-reversal invariant Weyl superconductors

    Vira Shyta🇩🇪 · Jeroen van den Brink🇩🇪 · Flavio S. Nogueira🇩🇪

    Weyl semimetals have nodes in their electronic structure at which electrons attain a definite chirality. Due to the chiral anomaly, the non-conservation of charges with given chirality, the axion term appears in their effective electromagnetic action. We determine how this affects the properties of time-reversal invariant Weyl {\it superconductors} (SCs) in the London regime. For type II SCs the axion coupling generates magnetic $B$-fields transverse to vortices, which become unstable at a critical coupling so that a transition into type I SC ensues. In this regime an applied $B$-field not only decays inside the SC within the London penetration depth, but the axion coupling generates an additional perpendicular field. Consequently, when penetrating into the bulk the $B$-field starts to steadily rotate away from the applied field. At a critical coupling the screening of the magnetic field breaks down. The novel chiral superconducting state that emerges has a periodically divergent susceptibility that separates onsets of chiral Meissner regimes. The chiral anomaly thus leaves very crisp experimental signatures in structurally chiral Weyl SCs with an axion response.

    ↳ cond-mat.supr-conhep-phhep-thPRResearch(2024)·6 citations
37. 37*

    The Possibility of Tachyons as Soliton Solutions in 3+1 Dimensions via k-field Models

    Mohammad Mohammadi🇮🇷

    Tachyons or hypothetical faster-than-light (FTL) particles would fail the principle of causality. Such particles may only be imagined when they have no energy and momentum and, thus, no observable interaction. In this paper, we show that the classical relativistic field theory with non-standard Lagrangian densities (k-field models) does not rule out the existence of FTL particle-like solutions (solitons) with zero energy and momentum in 3+1 dimensions. However, contrary to our expectation, we show that it is possible to have k-field models that lead to energetic FTL soliton solutions in 3+1 dimensions.

    ↳ gr-qchep-phhep-thAnnals Phys.(2024)·0 citations
38. 38*

    Averaged Null Energy and the Renormalization Group

    Thomas Hartman🇺🇸 · Grégoire Mathys🇺🇸

    We establish a connection between the averaged null energy condition (ANEC) and the monotonicity of the renormalization group, by studying the light-ray operator $\int du{T}_{uu}$ in quantum field theories that flow between two conformal fixed points. In four dimensions, we derive an exact sum rule relating this operator to the Euler coefficient in the trace anomaly, and show that the ANEC implies the a-theorem. The argument is based on matching anomalies in the stress tensor 3-point function, and relies on special properties of contact terms involving light-ray operators. We also illustrate the sum rule for the example of a free massive scalar field. Averaged null energy appears in a variety of other applications to quantum field theory, including causality constraints, Lorentzian inversion, and quantum information. The quantum information perspective provides a new derivation of the $a$-theorem from the monotonicity of relative entropy. The equation relating our sum rule to the dilaton scattering amplitude in the forward limit suggests an inversion formula for non-conformal theories.

    ↳ hep-thhep-phJHEP(2023)·56 citations
39. 39*

    Flux Correlators and Semiclassics

    Eren Firat🇨🇭 · Alexander Monin🇨🇭 · Riccardo Rattazzi🇨🇭 · Matthew T. Walters🇨🇭

    We consider correlators for the flux of energy and charge in the background of operators with large global $U(1)$ charge in conformal field theory (CFT). It has recently been shown that the corresponding Euclidean correlators generically admit a semiclassical description in terms of the effective field theory (EFT) for a conformal superfluid. We adapt the semiclassical description to Lorentzian observables and compute the leading large charge behavior of the flux correlators in general $U(1)$ symmetric CFTs. We discuss the regime of validity of the large charge EFT for these Lorentzian observables and the subtleties in extending the EFT approach to subleading corrections. We also consider the Wilson-Fisher fixed point in $d=4-ϵ$ dimensions, which offers a specific weakly coupled realization of the general setup, where the subleading corrections can be systematically computed without relying on an EFT.

    ↳ hep-thhep-phJHEP(2024)·18 citations
40. 40*

    Higher-form symmetry and chiral transport in real-time Abelian lattice gauge theory

    Arpit Das🇬🇧 · Adrien Florio🇺🇸 · Nabil Iqbal🇬🇧 · Napat Poovuttikul🇹🇭

    We study classical lattice simulations of theories of electrodynamics coupled to charged matter at finite temperature, interpreting them using the higher-form symmetry formulation of magnetohydrodynamics (MHD). We compute transport coefficients using classical Kubo formulas on the lattice and show that the properties of the simulated plasma are in complete agreement with the predictions from effective field theories. In particular, the higher-form formulation allows us to understand from hydrodynamic considerations the relaxation rate of axial charge in the chiral plasma observed in previous simulations. A key point is that the resistivity of the plasma -- defined in terms of Kubo formulas for the electric field in the 1-form formulation of MHD -- remains a well-defined and predictive quantity at strong electromagnetic coupling. However, the Kubo formulas used to define the conventional conductivity vanish at low frequencies due to electrodynamic fluctuations, and thus the concept of the conductivity of a gauged electric current must be interpreted with care.

    ↳ hep-thhep-lathep-phSciPost Phys.(2024)·10 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.