Wed·Oct 26, 2022Wednesday·October 26, 2022

1. 01*

   Collider probe of heavy additional Higgs bosons solving the muon $g-2$ and dark matter problems

   Monika Blanke🇩🇪 · Syuhei Iguro🇩🇪

   We study the Large Hadron Collider (LHC) search potential of a ${\mathbb{Z}}_4$-based two Higgs doublet model which can simultaneously explain the muon $g-2$ anomaly and the observed dark matter. The neutral scalars in the second Higgs doublet couple to $\mu$ and $\tau$ and largely contribute to the muon anomalous magnetic moment through the one-loop diagram involving $\tau$ and scalars. An additional singlet scalar which is charged under the discrete symmetry can be a dark matter candidate. An upper limit on the scalar mass originates from the unitarity constraint, and the $\mu \tau$ flavor-violating nature of the scalars predicts non-standard signatures at the LHC. However, the previously proposed ${\mu }^{\pm }{\mu }^{\pm }{\tau }^{\mp }{\tau }^{\mp }$ signal via the electroweak heavy neutral scalar pair production at the LHC loses sensitivity for increasing scalar mass. We revisit this model and investigate the LHC prospects for the single production of the $\mu \tau$ flavor-violating neutral scalar. It is shown that the single scalar process helps to extend the LHC reach to the 1TeV mass regime of the scenario. The search potential at the high energy LHC is also discussed.

   hep-phhep-exPRD(2023)·6 citations
2. 02*

   Optimal anti-ferromagnets for light dark matter detection

   Angelo Esposito🇮🇹 · Shashin Pavaskar🇺🇸

   We propose anti-ferromagnets as optimal targets to hunt for sub-MeV dark matter with spin-dependent interactions. These materials allow for multi-magnon emission even for very small momentum transfers, and are therefore sensitive to dark matter particles as light as the keV. We use an effective theory to compute the event rates in a simple way. Among the materials studied here, we identify nickel oxide (a well-assessed anti-ferromagnet) as an ideal candidate target. Indeed, the propagation speed of its gapless magnons is very close to the typical dark matter velocity, allowing the absorption of all its kinetic energy, even through the emission of just a single magnon.

   hep-phastro-ph.COcond-mat.mtrl-sciPRD(2023)·27 citations
3. 03*

   ${\alpha }_s$ from an improved $\tau$ vector isovector spectral function

   Diogo Boito🇧🇷 · Maarten Golterman🇺🇸 · Kim Maltman🇨🇦 · Santiago Peris🇪🇸 · Marcus V. Rodrigues🇧🇷 · Wilder Schaaf🇺🇸

   After discussing difficulties in determining ${\alpha }_s$ from tau decay due to the existence of Duality Violations and the associated asymptotic nature of the OPE, we describe a new determination based on an improved vector isovector spectral function, now based solely on experimental input, obtained by (i) combining ALEPH and OPAL results for $2\pi +4\pi$ and (ii) replacing $K^{-}{K}^0$ and higher-multiplicity exclusive-mode contributions, both previously estimated using Monte Carlo, with new experimental BaBar results for $K^{-}{K}^0$ and results implied by $e^{+}{e}^{-}$ cross sections and CVC for the higher-multiplicity modes. We find ${\alpha }_s(m_{\tau })=0.3077\pm 0.0075$, which corresponds to ${\alpha }_s(m_Z)=0.1171\pm 0.0010$. Finally, we comment on some of the shortcomings in the criticism of our approach by Pich and Rodriguez-Sanchez.

   hep-phhep-latEPJ Web Conf.(2022)·1 citation
4. 04*

   Gravitational Waves and Primordial Black Hole Productions from Gluodynamics by Holography

   Song He🇨🇳 · Li Li🇨🇳 · Zhibin Li🇨🇳 · Shao-Jiang Wang🇨🇳

   Understanding the nature of quantum chromodynamics (QCD) matter is important but challenging due to the presence of non-perturbative dynamics under extreme conditions. We construct a holographic model describing the gluon sector of QCD at finite temperatures in the non-perturbative regime. The equation of state as a function of temperature is in good accordance with the lattice QCD data. Moreover, the Polyakov loop and the gluon condensation, which are proper order parameters to capture the deconfinement phase transition, also agree quantitatively well with the lattice QCD data. We obtain a strong first-order confinement/deconfinement phase transition at $T_c=276.5\text{MeV}$ that is consistent with the lattice QCD prediction. Based on our model for a pure gluon hidden sector, we compute the stochastic gravitational waves and primordial black hole (PBH) productions from this confinement/deconfinement phase transition in the early Universe. The resulting stochastic gravitational-wave backgrounds are found to be within detectability in the International Pulsar Timing Array and Square Kilometre Array in the near future when the associated productions of PBHs saturate the current observational bounds on the PBH abundances from the LIGO-Virgo-Collaboration O3 data.

   hep-phastro-ph.COgr-qchep-thSCPMA(2024)·75 citations
5. 05*

   CMB imprints of high scale non-thermal leptogenesis

   Anish Ghoshal🇵🇱 · Dibyendu Nanda🇰🇷 · Abhijit Kumar Saha🇮🇳

   We study the imprints of high scale non-thermal leptogenesis on cosmic microwave background (CMB) from the measurements of inflationary spectral index ($n_s$) and tensor-to-scalar ratio ($r$), which otherwise is inaccessible to the conventional laboratory experiments. We argue that non-thermal production of baryon (lepton) asymmetry from subsequent decays of inflaton to heavy right-handed neutrinos (RHN) and RHN to SM leptons is sensitive to the reheating dynamics in the early Universe after the end of inflation. Such dependence provides detectable imprints on the $n_s-r$ plane which is well constrained by the Planck experiment. We investigate two separate cases, (I) inflaton decays to radiation dominantly and (II) inflaton decays to RHN dominantly which further decays to the SM particles to reheat the Universe adequately. Considering a class of $\alpha -$ attractor inflation models, we obtain the allowed mass ranges for RHN for both cases and thereafter furnish the estimates for $n_s$ and $r$. The prescription proposed here is general and can be implemented in various kinds of single-field inflationary models given the conditions for non-thermal leptogenesis are satisfied.

   hep-phastro-ph.COPLB(2024)·22 citations
6. 06*

   The Role of a Heavy Neutrino in the Gamma-Ray Burst GRB-221009A

   Kingman Cheung🇹🇼

   Recently, several telescopes, including Swift-BAT, GBM, and LHAASO, have observed the ever highest-energy and long-duration gamma-rays from a gamma-ray burst named as GRB221009A (located at a red-shift of $z=0.151$) on October 9, 2022. Conventional understanding tells us that very high-energy photons produced at such a far distance suffer severe attenuation before reaching the Earth. We propose the existence of a sub-MeV to $O(10)$ MeV heavy neutrino with a transitional magnetic dipole moment, via which the heavy neutrino is produced at the GRB. It then travels a long distance to our galaxy and decays into a neutrino and a photon, which is observed. In such a way, the original high-energy photon produced at the GRB can survive long-distance attenuation.

   hep-phastro-ph.HE20 citations
7. 07*

   Friction on ALP domain walls and gravitational waves

   Simone Blasi🇧🇪 · Alberto Mariotti🇧🇪 · Aäron Rase🇧🇪 · Alexander Sevrin🇧🇪 · Kevin Turbang🇧🇪

   We study the early Universe evolution of axion-like particle (ALP) domain walls taking into account the effect of friction from particles in the surrounding plasma, including the case of particles in thermal equilibrium and frozen out species. We characterize the friction force from interactions within the ALP effective theory, providing new results for the fermion contribution as well as identifying simple conditions for friction to be relevant during the domain wall life time. When friction dominates, the domain wall network departs from the standard scaling regime and the corresponding gravitational wave emission is affected. As a relevant example, we show how this can be the case for ALP domain walls emitting at the typical frequencies of Pulsar Timing Array experiments, when the ALP couples to the SM leptons. We then move to a general exploration of the gravitational wave prospects in the ALP parameter space. We finally illustrate how the gravitational wave signal from ALP domain walls is correlated with the quality of the underlying $U(1)$ symmetry.

   hep-phJCAP(2023)·51 citations
8. 08*

   Potential for definitive discovery of a 70 GeV dark matter WIMP with only second-order gauge couplings

   Bailey Tallman🇺🇸 · Alexandra Boone🇺🇸 · Adhithya Vijayakumar🇺🇸 · Fiona Lopez🇺🇸 · Samuel Apata🇺🇸 · Jehu Martinez🇺🇸 · Roland Allen🇺🇸

   As astronomical observations and their interpretation improve, the case for cold dark matter (CDM) becomes increasingly persuasive. A particularly appealing version of CDM is a weakly interacting massive particle (WIMP) with a mass near the electroweak scale, which can naturally have the observed relic abundance after annihilation in the early universe. But in order for a WIMP to be consistent with the currently stringent experimental constraints it must have relatively small cross-sections for indirect, direct, and collider detection. Using our calculations and estimates of these cross-sections, we discuss the potential for discovery of a recently proposed dark matter WIMP which has a mass of about 70 GeV/c${}^2$ and only second-order couplings to W and Z bosons. There is evidence that indirect detection may already have been achieved, since analyses of the gamma rays detected by Fermi-LAT and the antiprotons observed by AMS-02 are consistent with 70 GeV dark matter having our calculated $⟨{\sigma }_{ann}v⟩\approx 1.2\times 10^{-26}$ cm${}^3$/s. The estimated sensitivities for LZ and XENONnT indicate that these experiments may achieve direct detection within the next few years, since we estimate the relevant cross-section to be slightly above $10^{-48}$ cm${}^2$. Other experiments such as PandaX, SuperCDMS, and especially DARWIN should be able to confirm on a longer time scale. The high-luminosity LHC might achieve collider detection within about 15 years, since we estimate a collider cross-section slightly below 1 femtobarn. Definitive confirmation should come from still more powerful planned collider experiments (such as a future circular collider) within 15-35 years.

   hep-phLHEP(2023)·6 citations
9. 09*

   One-loop hexagon integral to higher orders in the dimensional regulator

   Johannes M. Henn🇩🇪 · Antonela Matijašić🇩🇪 · Julian Miczajka🇩🇪

   The state-of-the-art in current two-loop QCD amplitude calculations is at five-particle scattering. Computing two-loop six-particle processes requires knowledge of the corresponding one-loop amplitudes to higher orders in the dimensional regulator. In this paper we compute analytically the one-loop hexagon integral via differential equations. In particular we identify its function alphabet for general $D$-dimensional external states. We also provide integral representations for all one-loop integrals up to weight four. With this, the one-loop integral basis is ready for two-loop amplitude applications. We also study in detail the difference between the conventional dimensional regularization and the four-dimensional helicity scheme at the level of the master integrals and their function space.

   ↳ hep-thhep-phJHEP(2023)·25 citations
10. 10*

    The gaugino condensate from asymmetric four-torus with twists

    Mohamed M. Anber🇬🇧 · Erich Poppitz🇨🇦

    We calculate the gaugino condensate in $SU(2)$ super Yang-Mills theory on an asymmetric four-torus ${\mathbb{T}}^4$ with 't Hooft's twisted boundary conditions. The ${\mathbb{T}}^4$ asymmetry is controlled by a dimensionless detuning parameter $\Delta$, proportional to $L_3{L}_4-L_1{L}_2$, with $L_i$ denoting the ${\mathbb{T}}^4$ periods. We perform our calculations via a path integral on a ${\mathbb{T}}^4$. Its size is taken much smaller than the inverse strong scale $\Lambda$ and the theory is well inside the semi-classical weak-coupling regime. The instanton background, constructed for $\Delta \ll 1$ in arXiv:hep-th/0007113, has fractional topological charge $Q=\frac{1}{2}$ and supports two gaugino zero modes, yielding a non-vanishing bilinear condensate, which we find to be $\Delta$-independent. Further, the theory has a mixed discrete chiral/$1$-form center anomaly leading to double degeneracy of the energy eigenstates on any size torus with 't Hooft twists. In particular, there are two vacua, $|0⟩$ and $|1⟩$, that are exchanged under chiral transformation. Using this information, the $\Delta$-independence of the condensate, and assuming further that the semi-classical theory is continuously connected to the strongly-coupled large-${\mathbb{T}}^4$ regime, we determine the numerical coefficient of the gaugino condensate: $⟨0|\text{mbox}tr\lambda \lambda |0⟩=|⟨1|\text{mbox}tr\lambda \lambda |1⟩|=32{\pi }^2{\Lambda }^3$, a result equal to twice the known ${\mathbb{R}}^4$ value. We discuss possible loopholes in the continuity approach that may lead to this discrepancy.

    ↳ hep-thhep-lathep-phJHEP(2023)·25 citations
11. 11*

    Spectral-weight sum rules for the hadronic vacuum polarization

    Diogo Boito🇧🇷 · Maarten Golterman🇺🇸 · Kim Maltman🇨🇦 · Santiago Peris🇪🇸

    We develop a number of sum rules comparing spectral integrals involving judiciously chosen weights to integrals over the corresponding Euclidean two-point function. The applications we have in mind are to the hadronic vacuum polarization that determines the most important hadronic correction $a_{\mu }^{\mathrm{HVP}}$ to the muon anomalous magnetic moment. First, we point out how spectral weights may be chosen that emphasize narrow regions in $\sqrt{s}$, providing a tool to investigate emerging discrepancies between data-driven and lattice determinations of $a_{\mu }^{\mathrm{HVP}}$. Alternatively, for a narrow region around the $\rho$ mass, they may allow for a comparison of the dispersive determination of $a_{\mu }^{\mathrm{HVP}}$ with lattice deteruminations zooming in on the region of the well-known BaBar-KLOE discrepancy. Second, we show how such sum rules can in principle be used for carrying out precision comparisons of hadronic-$\tau$-decay-based data and $e^{+}{e}^{-}\to \text{mbox}hadrons(\gamma )$-based data, where lattice computations can provide the necessary isospin-breaking corrections.

    ↳ hep-lathep-phPRD(2023)·25 citations
12. 12*

    Jet tagging algorithm of graph network with HaarPooling message passing

    Fei Ma🇨🇳 · Feiyi Liu🇨🇳 · Wei Li🇨🇳

    Recently methods of graph neural networks (GNNs) have been applied to solving the problems in high energy physics (HEP) and have shown its great potential for quark-gluon tagging with graph representation of jet events. In this paper, we introduce an approach of GNNs combined with a HaarPooling operation to analyze the events, called HaarPooling Message Passing neural network (HMPNet). In HMPNet, HaarPooling not only extracts the features of graph, but embeds additional information obtained by clustering of k-means of different particle features. We construct Haarpooling from five different features: absolute energy $\log E$, transverse momentum $\log p_T$, relative coordinates $(\Delta \eta ,\Delta \varphi )$, the mixed ones $(\log E,\log p_T)$ and $(\log E,\log p_T,\Delta \eta ,\Delta \varphi )$. The results show that an appropriate selection of information for HaarPooling enhances the accuracy of quark-gluon tagging, as adding extra information of $\log P_T$ to the HMPNet outperforms all the others, whereas adding relative coordinates information $(\Delta \eta ,\Delta \varphi )$ is not very effective. This implies that by adding effective particle features from HaarPooling can achieve much better results than solely pure message passing neutral network (MPNN) can do, which demonstrates significant improvement of feature extraction via the pooling process. Finally we compare the HMPNet study, ordering by $p_T$, with other studies and prove that the HMPNet is also a good choice of GNN algorithms for jet tagging.

    ↳ hep-excs.CVcs.LGhep-phPRD(2023)·20 citations
13. 13*

    The LHCspin project

    M. Santimaria🇮🇹 · V. Carassiti🇮🇹 · G. Ciullo🇮🇹 · P. Di Nezza🇮🇹 · P. Lenisa🇮🇹 · S. Mariani🇮🇹 · L. L. Pappalardo🇮🇹 · E. Steffens🇩🇪

    The goal of LHCspin is to develop, in the next few years, innovative solutions and cutting-edge technologies to access spin physics in polarised fixed-target collisions at high energy, exploring the unique kinematic regime offered by LHC and exploiting new final states by means of the LHCb detector.

    ↳ hep-exhep-ph1 citation
14. 14*

    Characterizing the initial and final state effects of relativistic nuclear collisions

    Niseem Magdy🇺🇸

    The Multi-Phase Transport model (AMPT) is used to study the final state effects on the Symmetric Correlations (SC), Asymmetric Correlations (ASC), Normalized Symmetric Correlations (NSC), and Normalized Asymmetric Correlations (NASC) in Au+Au collisions at 200~GeV. The correlators' sensitivity to non-flow effects associated with long- and short-range non-flow correlations are also discussed using the HIJING model. The results indicate that SC, ASC, NSC, and NASC can give accompanying constraints for initial and final state effects. In addition, conducting further detailed experimental measurements spanning a broad range of collision systems and beam energies will serve as an additional constraint for the theoretical models' calculations.

    ↳ nucl-thhep-phnucl-exPRC(2023)·14 citations
15. 15*

    Heavy primordial black holes from strongly clustered light black holes

    Valerio De Luca🇺🇸 · Gabriele Franciolini🇮🇹 · Antonio Riotto🇨🇭

    We show that heavy primordial black holes may originate from much lighter ones if the latter are strongly clustered at the time of their formation. While this population is subject to the usual constraints from late-time universe observations, its relation to the initial conditions is different from the standard scenario and provides a new mechanism to generate massive primordial black holes even in the absence of efficient accretion, opening new scenarios, e.g. for the generation of supermassive black holes.

    ↳ astro-ph.COgr-qchep-phhep-thPRL(2023)·40 citations
16. 16*

    Analytic continuation of harmonic sums with purely imaginary indices near the integer values

    V.N. Velizhanin🇷🇺

    We present a simple algebraic method for the analytic continuation of harmonic sums with integer real or purely imaginary indices near negative and positive integers. We provide a MATHEMATICA code for exact expansion of harmonic sums in a small parameter near these integers. As an application, we consider the analytic continuation of the anomalous dimension of twist-1 operators in ABJM model, which contains the nested harmonic sums with purely imaginary indices. We found that in the BFKL-like limit the result has the same single-logarithmic behavior as in N=4 SYM and QCD, however, we did not find a general expression for the ``BFKL Pomeron'' eigenvalue in this model. For the slope function, we found full agreement with the expansion of the known general result and give predictions for the first three perturbative terms in the expansion of the next-to-slope function. The proposed method of analytic continuation can also be used for other generalization of the nested harmonic sums.

    ↳ hep-thhep-phInt.J.Mod.Phys.A(2023)·3 citations
17. 17*

    A new quantization principle from a minimally non time-ordered product

    Damiano Anselmi🇮🇹

    We formulate a new quantization principle for perturbative quantum field theory, based on a minimally non time-ordered product, and show that it gives the theories of physical particles and purely virtual particles. Given a classical Lagrangian, the quantization proceeds as usual, guided by the time-ordered product, up to the common scattering matrix $S$, which satisfies a unitarity or a pseudounitarity equation. The physical scattering matrix $S_{\text{ph}}$ is built from $S$, by gluing $S$ diagrams together into new diagrams, through non time-ordered propagators. We classify the most general way to gain unitarity by means of such operations, and point out that a special solution "minimizes" the time-ordering violation. We show that the scattering matrix $S_{\text{ph}}$ given by this solution coincides with the one obtained by turning the would-be ghosts (and possibly some would-be physical particles) into purely virtual particles (fakeons). We study tricks to descend and ascend in a unique way among diagrams, and illustrate them in several examples: the ascending chain from the bubble to the hexagon, at one loop; the box with diagonal, at two loops; other diagrams, with more loops.

    ↳ hep-thhep-phJHEP(2022)·14 citations
18. 18*

    CaloFlow for CaloChallenge Dataset 1

    Claudius Krause🇺🇸 · Ian Pang🇺🇸 · David Shih🇺🇸

    CaloFlow is a new and promising approach to fast calorimeter simulation based on normalizing flows. Applying CaloFlow to the photon and charged pion Geant4 showers of Dataset 1 of the Fast Calorimeter Simulation Challenge 2022, we show how it can produce high-fidelity samples with a sampling time that is several orders of magnitude faster than Geant4. We demonstrate the fidelity of the samples using calorimeter shower images, histograms of high-level features, and aggregate metrics such as a classifier trained to distinguish CaloFlow from Geant4 samples.

    ↳ physics.ins-detcs.LGhep-exhep-ph+1SciPost Phys.(2024)·55 citations
19. 19*

    Optical scalar beam propagation in nontrivial spacetime backgrounds

    C. A. Escobar🇲🇽 · A. Martín-Ruiz🇲🇽 · M. Mondragón🇲🇽 · R. Jáuregui

    We study the propagation of structured optical scalar beams in a spacetime background parameterized by a second-rank symmetric tensor. An analytic expression for the Green's function in a cylindrical coordinate system is obtained for particular choices of such a tensor. This facilitates the numerical exploration of the propagation of apertured Gaussian beams in this nontrivial background. Unusual focusing properties are found along with a decrease in the Gouy phase compared to that in standard vacuum. In the case of apertured Bessel beams, the medium allows to overcome finite aperture effects so that the corresponding diffraction length is increased; besides, the central spot of a zero order Bessel concentrates an increased fraction of the energy of the beam. Multiple scenarios beyond an electromagnetic field in the presence of an anisotropic medium could support the results reported here. They include a bosonic field in a weak gravitational field or a nontrivial spacetime background arising from Lorentz symmetry breaking. In particular, our results could illustrate how optically transparent multiferroic materials offer unprecedented opportunities to tailor structured beam propagation, as well as to simulate nontrivial spacetime backgrounds.

    ↳ physics.opticshep-ph0 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.