Wed·Dec 27, 2023Wednesday·December 27, 2023

1. 01*

   Three-loop anomalous dimensions of fixed-charge operators in the SM

   A.V. Bednyakov (BLTP JINR)🇷🇺

   In this Letter we consider renormalization of a class of scalar operators with fixed hypercharge $Q$ within the Standard Model. We carry out explicit computation of the corresponding anomalous dimensions up to the three-loop order. In spite of the fact that our result is gauge-dependent, in the Landau gauge and in the limit of vanishing weak isospin coupling the expression can be matched to recent gauge-independent computation based on the large-charge method. Our result serves an important and non-trivial cross-check of new developments in large-charge expansion and applications of the latter to realistic gauge theories. We not only confirm the leading and subleading terms in perturbative $Q$ expansion up to three loops, but also provide the expressions for sub-subleading coefficients that at the moment are not captured by the large-charge approach.

   hep-phhep-thPLB(2024)·4 citations
2. 02*

   Fermion Masses, Neutrino Mixing and Higgs-Mediated Flavor Violation in 3HDM with $S_3$ Permutation Symmetry

   K.S. Babu🇺🇸 · Yongcheng Wu🇨🇳 · Shiyuan Xu🇺🇸

   The Yukawa and scalar sectors of a general $S_3$-symmetric three-Higgs doublet model (3HDM) are investigated. The Yukawa interactions are constructed in an $S_3$-invariant way, while the scalar potential contains $S_3$ soft-breaking terms. Global fits to the quark/lepton masses and CKM/PMNS matrices are performed. Excellent fits to all fermion mass and mixing parameters are obtained. Both normal ordering and inverted ordering of neutrino masses are found to be admissible within the framework, with a prediction for the CP-violation phase, ${\delta }_{CP}\simeq 120^0$. The fit results in the Yukawa sector are further investigated, together with the scalar sector, imposing constraints from Higgs-mediated neutral meson mixing and neutron electric dipole moment (EDM). We explore the lowest allowed mass of the heavy Higgs bosons, consistent with these constraints, and find it to be about 17 TeV. The corresponding neutron EDM is around $1.7\times 10^{-27}$ e-cm, which is within reach of proposed experiments. It is found that the constraints from the $K$-meson system dominate, while those from the $D$ meson system are marginal.

   hep-phnucl-thJHEP(2024)·5 citations
3. 03*

   The MSSM compatibility with the limit on electron electric dipole moment

   S.S. AbdusSalam🇮🇷 · S.S. Barzani🇮🇷 · L. Kalhor🇮🇷 · M. Mohammadidoust🇮🇷 · S.A. Ojaghi🇮🇷

   The minimal supersymmetric standard model (MSSM) particles can generate loop-level radiative corrections that contribute to the electric dipole moment (EDM) of an electron. The upper bound on the EDM can therefore be used for delineating the MSSM parameters space. We use this setting to describe a direction of particle physics phenomenology research -- the global fits of particle physics models beyond the standard model. This is done within the context of the MSSM phenomenology framework with thirty free parameters (MSSM30). Using samples of MSSM30 parameter-space points constrained with the latest bound on the electron EDM, we show that Arg(mu M2) is the most constrained MSSM CP-violating phase. The EDM-compatible parameter regions feature multi-TeV pseudoscalar Higgs bosons and relatively lower "tan beta" values compared to previous analyses.

   hep-ph0 citations
4. 04*

   Dynamical simulations of colliding superconducting strings

   Takashi Hiramatsu🇯🇵 · Marc Lilley🇫🇷 · Daisuke Yamauchi🇯🇵

   We study the collisions of elastic superconducting strings, also referred to as current-carrying strings, formed in a $U_{\mathrm{local}}(1)\times U_{\mathrm{global}}(1)$ field-theory model, using three-dimensional numerical field-theoretic simulations. The breaking of $U_{\mathrm{local}}(1)$ leads to string formation via the Higgs mechanism, while the scalar field of the second $U_{\mathrm{global}}(1)$ carries the current, which condenses onto the string. We construct straight and static superconducting string solutions numerically and identify the regions in which they exist in the model parameter space. We then perform dynamical simulations for colliding superconducting strings with various collision angles and collision velocities. We explore the kinematic parameter space for six sets of model parameters characterising the coupling between the two scalar fields and the current on the string. The final states of the strings (after the collision) are reported diagrammatically. We classify them into four categories: (i) regular intercommutation, (ii) double intercommutation, (iii) bound state, and (iv) expanding string solution. We find that the outcome of the collision process is the regular intercommutation of the colliding strings in most of the kinematic parameter space while they form bound states for small velocities and small angles. We also find that the strings undergo two successive intercommutations and, therefore, pass through one other in a small region corresponding to relatively small angles and velocities of order c/2. The string structure breaks down when there is a relatively large coupling between the two scalar fields, even if each string is stable before the occurrence of the collision.

   hep-phastro-ph.COhep-thJCAP(2024)·5 citations
5. 05*

   An example of a bouncing dark matter -- EPS-HEP2023

   Bastián Díaz Sáez🇨🇱

   Thermal dark matter, which, after chemical decoupling from the Standard Model thermal plasma rises its yield before it freezes-out, is a new feature of thermal DM scenarios dubbed as "Bouncing Dark Matter". In the following short note, we introduce the topic, exemplifying the mechanism with a simple model that extends the SM with two dark matter particles, a fermion, and a pNGB, plus a second Higgs. We explore the features of the thermal freeze-out of this scenario, with particular emphasis on the exponential growth of the yield of the pNGB. We test the model under collider bounds, relic abundance, direct detection, and we study prospects for indirect detection observables.

   hep-phPoS(2024)·0 citations
6. 06*

   Sub-GeV Gamma Rays from Nearby Seyfert Galaxies and Implications for Coronal Neutrino Emission

   Kohta Murase🇺🇸 · Christopher M. Karwin🇺🇸 · Shigeo S. Kimura🇯🇵 · Marco Ajello🇺🇸 · Sara Buson🇩🇪

   Recent observations of high-energy neutrinos by IceCube and gamma rays by the Fermi Large Area Telescope (LAT) and the MAGIC telescope have suggested that neutrinos are produced in gamma-ray opaque environments in the vicinity of supermassive black holes. In this work, we present 20 MeV - 1 TeV spectra of three Seyfert galaxies whose nuclei are predicted to be active in neutrinos, NGC 4151, NGC 4945 and the Circinus galaxy, using 14.4 yr of the Fermi LAT data. In particular, we find evidence of sub-GeV excess emission that can be attributed to gamma rays from NGC 4945, as was also seen in NGC 1068. These spectral features are consistent with predictions of the magnetically powered corona model, and we argue that NGC 4945 is among the brightest neutrino active galaxies detectable for KM3Net and Baikal-GVD. On the other hand, in contrast to other reported results, we do not detect gamma rays from NGC 4151, which constrains neutrino emission from the accretion shock model. Future neutrino detectors such as IceCube-Gen2 and MeV gamma-ray telescopes such as AMEGO-X will be crucial for discriminating among the theoretical models.

   ↳ astro-ph.HEastro-ph.GAhep-phApJ(2024)·53 citations
7. 07*

   Excluded volume effects in the quark-mass density-dependent model: implications for the equation of state and compact star structure

   G. Lugones🇧🇷 · A. G. Grunfeld🇦🇷

   We present a significant extension of the quark mass density-dependent model (QMDDM), initially revised in our prior study (Lugones and Grunfeld, Phys. Rev. D 107, 043025 (2023)), where thermodynamic inconsistencies were addressed. Our current work enriches the QMDDM by incorporating excluded volume effects, as a step towards a more realistic representation of the quark matter equation of state (EOS) at zero temperature. We introduce the concept of ``available volume'' in the Helmholtz free energy formulation, accounting for the space excluded by each quasiparticle due to its finite size or repulsive interactions. We present a methodology to modify the EOS for point-like particles, allowing for a simple and direct incorporation of excluded volume effects. This is first addressed in a simple one-flavor model and then extended to a more realistic three-flavor system, incorporating both mass and volume dependencies on the baryon number density. We examine various ansatzes for the excluded volume, ultimately adopting one that aligns with the asymptotic freedom behavior of Quantum Chromodynamics (QCD). The EOS for electrically neutral systems in chemical equilibrium is computed, focusing on self-bound and hybrid matter scenarios. We show that the incorporation of excluded volume effects renders the EOS stiffer and that excluded volume effects are essential to align the mass-radius relation of self-bound and hybrid stars with modern astrophysical constraints.

   ↳ nucl-thastro-ph.HEastro-ph.SRhep-phPRD(2024)·6 citations
8. 08*

   Emergent Gravity Completion in Quantum Field Theory, and Affine Condensation in Open and Closed Strings

   Durmuş Demir🇹🇷

   The ultraviolet cutoff on a quantum field theory can be interpreted as a condensate of the affine curvature such that while the maximum of the affine action gives the power-law corrections, its minimum leads to the emergence of gravity. This mechanism applies also to fundamental strings as their spinless unstable ground levels can be represented by the scalar affine curvature such that open strings (D-branes) decay to closed strings and closed strings to finite minima with emergent gravity. Affine curvature is less sensitive to massive string levels than the tachyon, and the field-theoretic and stringy emergent gravities take the same form. It may be that affine condensation provides an additional link between the string theory and the known physics at low energies.

   ↳ hep-thgr-qchep-ph3 citations
9. 09*

   Hidden zeros for particle/string amplitudes and the unity of colored scalars, pions and gluons

   Nima Arkani-Hamed🇺🇸 · Qu Cao🇨🇳 · Jin Dong🇨🇳 · Carolina Figueiredo🇺🇸 · Song He🇨🇳

   Recent years have seen the emergence of a new understanding of scattering amplitudes in the simplest theory of colored scalar particles - the Tr$({\varphi }^3)$ theory - based on combinatorial and geometric ideas in the kinematic space of scattering data. In this paper we report a surprise: far from the toy model it appears to be, the ''stringy'' Tr$({\varphi }^3)$ amplitudes secretly contain the scattering amplitudes for pions, as well as non-supersymmetric gluons, in any number of dimensions. The amplitudes for the different theories are given by one and the same function, related by a simple shift of the kinematics. This discovery was spurred by another fundamental observation: the tree-level Tr$({\varphi }^3)$ field theory amplitudes have a hidden pattern of zeros when a special set of non-planar Mandelstam invariants is set to zero. Furthermore, near these zeros, the amplitudes simplify, by factoring into a non-trivial product of smaller amplitudes. Remarkably the amplitudes for pions and gluons are observed to also vanish in the same kinematical locus. These properties further generalize to the ''stringy'' Tr$({\varphi }^3)$ amplitudes. There is a unique shift of the kinematic data that preserves the zeros, and this shift is precisely the one that unifies colored scalars, pions, and gluons into a single object. We will focus in this paper on explaining the hidden zeros and factorization properties and the connection between all the colored theories, working for simplicity at tree-level. Subsequent works will describe this new formulation for the Non-linear Sigma Model and non-supersymmetric Yang-Mills theory, at all loop orders.

   ↳ hep-thhep-phJHEP(2024)·108 citations
10. 10*

    BGK subgrid model for neutrino quantum kinetics

    Hiroki Nagakura🇯🇵 · Lucas Johns🇺🇸 · Masamichi Zaizen🇯🇵

    We present a new subgrid model for neutrino quantum kinetics, which is primarily designed to incorporate effects of collective neutrino oscillations into neutrino-radiation-hydrodynamic simulations for core-collapse supernovae and mergers of compact objects. We approximate the neutrino oscillation term in quantum kinetic equation by Bhatnagar-Gross-Krook (BGK) relaxation-time prescription, and the transport equation is directly applicable for classical neutrino transport schemes. The BGK model is motivated by recent theoretical indications that non-linear phases of collective neutrino oscillations settle into quasi-steady structures. We explicitly provide basic equations of the BGK subgrid model for both multi-angle and moment-based neutrino transport to facilitate the implementation of the subgrid model in the existing neutrino transport schemes. We also show the capability of our BGK subgrid model by comparing to fully quantum kinetic simulations for fast neutrino-flavor conversion. We find that the overall properties can be well reproduced in the subgrid model; the error of angular-averaged survival probability of neutrinos is within $\sim 20\%$. By identifying the source of error, we also discuss perspectives to improve the accuracy of the subgrid model.

    ↳ astro-ph.HEgr-qchep-phphysics.comp-phPRD(2024)·50 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.