Mon·Aug 30, 2021Monday·August 30, 2021

1. 01*

   Ghost and Tachyon Free Propagation up to spin-3 in Lorentz Invariant Field Theories

   Carlo Marzo🇪🇪

   We complete the set of spin-projector operators for fields up to rank-3 by providing all operators connecting sectors with same spin and parity. In this way we can broaden the search for unitary and non-tachyonic particle propagation in quadratic lagrangian with inter-field mixing. We use the properties of projector algebra to reanalyze known theories and shed light towards new healthy ones. We do so with full control over the gauge constraints by working the form of the saturated propagator in an appropriate frame of reference.

   hep-phhep-thPRD(2022)·30 citations
2. 02*

   Transverse Momentum and Transverse Momentum Distributions in the MIT Bag Model

   A. I. Signal🇳🇿 · F. G. Cao🇳🇿

   The typical transverse momentum of a quark in the proton is a basic property of any QCD based model of nucleon structure. However, calculations in phenomenological models typically give rather small values of transverse momenta, which are difficult to reconcile with the larger values observed in high energy experiments such as Drell-Yan reactions and Semi-inclusive deep inelastic scattering. In this letter we calculate the leading twist transverse momentum dependent distribution functions (TMDs) using a generalization of the Adelaide group's relativistic formalism that has previously given good fits to the parton distributions. This enables us to examine the $k_T$ dependence of the TMDs in detail, and determine typical widths of these distributions. These are found to be significantly larger than those of previous calculations. We then use TMD factorization in order to evolve these distributions up to experimental scales where we can compare with data on $⟨k_T⟩$ and $⟨k_T^2⟩$. Our distributions agree well with this data.

   hep-phnucl-thPLB(2022)·13 citations
3. 03*

   Electroweak-Skyrmion as Asymmetric Dark Matter

   Yu Hamada🇯🇵 · Ryuichiro Kitano🇯🇵 · Masafumi Kurachi🇯🇵

   We propose a scenario that the Electroweak-Skyrmion, a solitonic object made of the Higgs field and the electroweak gauge fields, is identified as an asymmetric dark matter. In this scenario, the relic abundance of the dark matter is related to the baryon asymmetry of the Universe through a sphaleron-like process. We show that the observed ratio of dark matter abundance to the baryon asymmetry can be explained by this scenario with an appropriate choice of model parameters that is allowed by currently available experimental constraints.

   hep-phastro-ph.COhep-thJHEP(2022)·5 citations
4. 04*

   Mass Spectra and Decay of Mesons under Strong External Magnetic Field

   Shuyun Yang🇨🇳 · Meng Jin🇨🇳 · Defu Hou🇨🇳

   We study the mass spectra and decay process of $\sigma$ and ${\pi }_0$ mesons under strong external magnetic field. For this purpose, we deduce the thermodynamic potential in a two-flavor, hot and magnetized Nambu-Jona-Lasinio model. We calculate the energy gap equation through the random phase approximation(RPA). Then we use Ritus method to calculate the decay triangle diagram and self-energy in the presence of a constant magnetic field B. Our results indicate that the magnetic field has little influence on the mass of ${\pi }_0$ at low temperatures. While for quarks and $\sigma$ mesons, their mass changes obviously, which reflects the influence of magnetic catalysis(MC). The presence of magnetic field accelerates the decay of the meson while the presence of chemical potential will decrease the decay process.

   hep-phCPC(2022)·6 citations
5. 05*

   0.5 eV QCD Axion Cosmology

   Noah Bray-Ali🇨🇦

   The best available determination of the present expansion rate of the universe using late-universe observations, by the SH0ES collaboration in 2025, differs by more than seven standard deviations from the value of the Hubble constant determined by the Planck collaboration in 2018 using early-universe observations and the standard cold dark matter cosmology with cosmological constant, a discrepancy known as the Hubble tension. Within a spatially flat, isotropic, and homogeneous expanding-universe solution of the field equations of general relativity with cosmological constant, the SH0ES value for the Hubble constant implies roughly twice as many baryons as the standard cosmology, provided that one retains the Planck values for the energy density of cold dark matter in the present universe and for the cosmological constant. A novel cosmology is proposed --- in terms of cooling dark matter made of quantum chromodynamic (QCD) axions with present number density six times that of the photons in the cosmic microwave background --- which realizes this straightforward, doubled-baryons scenario for resolving the Hubble tension.

   hep-phcond-mat.str-elhep-exhep-th1 citation
6. 06*

   Quantum fluctuation in an inhomogeneous background and its influence on the phase transition in a finite volume system

   Xiaogang Li🇨🇳 · Song Shu🇨🇳 · Jia-Rong Li🇨🇳

   We have studied the grand potential and phase transitions of an inhomogeneous finite volume spherical quark system. First the finite volume effects are considered by applying the multiple reflection expansion method which is an approximation for the density of states of the momentum in the grand potential of the finite size system. Then, the density of states of momentum is further modified by the thermal fluctuations in the thermal system with the inhomogeneous field background. The modification of the density of states is calculated by the scattering phase shift from the Dirac equation of quarks in the inhomogeneous field background. By the numerical calculation we show how the phase transition is changed by varying the configuration of the inhomogeneous field background and find that the strong first order phase transition could be weakened or even changed to a crossover as a result.

   hep-phnucl-thPRC(2022)·6 citations
7. 07*

   Hadronic light-by-light contribution to the muon $g-2$ from holographic QCD with massive pions

   Josef Leutgeb🇦🇹 · Anton Rebhan🇦🇹

   We extend our previous calculations of the hadronic light-by-light scattering contribution to the muon anomalous magnetic moment in holographic QCD to models with finite quark masses and a tower of massive pions. Analysing the role of the latter in the Wess-Zumino-Witten action, we show that the Melnikov-Vainshtein short-distance constraint is satisfied solely by the summation of contributions from the infinite tower of axial vector meson contributions. There is also an enhancement of the asymptotic behavior of pseudoscalar contributions when their infinite tower of excitations is summed, but this leads only to subleading contributions for the short-distance constraints on light-by-light scattering. We also refine our numerical evaluations, particularly in the pion and $a_1$ sector, which corroborates our previous findings of contributions from axial vector mesons that are significantly larger than those adopted for the effects of axials and short-distance constraints in the recent White Paper on the Standard Model prediction for $(g-2{)}_{\mu }$.

   hep-phhep-thPRD(2021)·46 citations
8. 08*

   Neutrinos from captured dark matter annihilation in a galactic population of neutron stars

   Debajit Bose🇮🇳 · Tarak Nath Maity🇮🇳 · Tirtha Sankar Ray🇮🇳

   Particulate dark matter captured by a population of neutron stars distributed around the galactic center while annihilating through long-lived mediators can give rise to an observable neutrino flux. We examine the prospect of an idealised gigaton detector like IceCube/KM3NeT in probing such scenarios. Within this framework, we report an improved reach in spin-dependent and spin-independent dark matter nucleon cross-section below the current limits for dark matter masses in the TeV-PeV range.

   hep-phastro-ph.GAastro-ph.HEJCAP(2022)·48 citations
9. 09*

   General Kinetic Mixing in Gauged $U(1{)}_{L_{\mu }-L_{\tau }}$ Model for Muon $g-2$ and Dark Matter

   Timothy Hapitas🇨🇦 · Douglas Tuckler🇨🇦 · Yue Zhang🇨🇦

   The gauged $U(1{)}_{L_{\mu }-L_{\tau }}$ extension of the Standard Model is a very simple framework that can alleviate the tension in muon anomalous magnetic dipole moment, reinforced by the recent Fermilab measurement. We explore experimental probes of the $(g-2{)}_{\mu }$ target with a general treatment of kinetic mixing between the $Z^{\prime }$ gauge boson and the photon. The physical value of the kinetic mixing depends on a free parameter of the model and energy scale of a process. We find neutrino constraints on the $(g-2{)}_{\mu }$ target including Borexino, CE$\nu$NS, and white dwarfs are sensitive to this freedom and can be lifted if the kinetic mixing lies in proximity of zero at low momentum transfer. As a further step, we explore $L_{\mu }-L_{\tau }$ charged dark matter with a thermal origin and show that the same scenario of kinetic mixing can relax existing direct detection constraints and predict novel recoil energy dependence in the upcoming searches. Future joint effort of neutrino and dark matter experiments and precision spectral measurement will be the key to test such a theory.

   hep-phastro-ph.COhep-exPRD(2022)·39 citations
10. 10*

    Dynamical model of $\varphi$ meson photoproduction on the nucleon and ${}^{4}He$

    Sang-Ho Kim🇰🇷 · T.-S. H. Lee🇺🇸 · Seung-il Nam🇰🇷 · Yongseok Oh🇰🇷

    We investigate $\varphi$ meson photoproduction on the nucleon and the \nuclide[4]{He} targets within a dynamical model approach based on a Hamiltonian which describes the production mechanisms by the Pomeron-exchange, meson-exchanges, $\varphi$ radiations, and nucleon resonance excitations mechanisms. The final $\varphi N$ interactions are included being described by the gluon-exchange, direct $\varphi N$ couplings, and the box-diagrams arising from the couplings with $\pi N$, $\rho N$, $K\Lambda$, and $K\Sigma$ channels. The parameters of the Hamiltonian are determined by the experimental data of $\gamma p\to \varphi p$ from the CLAS Collaboration. The resulting Hamiltonian is then used to predict the coherent $\varphi$-meson production on the \nuclide[4]{He} targets by using the distorted-wave impulse approximation. For the proton target, the final $\varphi N$ rescattering effects, as required by the unitarity condition, are found to be very weak, which supports the earlier calculations in the literature. For the \nuclide[4]{He} targets, the predicted differential cross sections are in good agreement with the data obtained by the LEPS Collaboration. The role of each mechanism in this reaction is discussed and predictions for a wide range of scattering angles are presented, which can be tested in future experiments.

    ↳ nucl-thhep-phnucl-exPRC(2021)·19 citations
11. 11*

    Domain Wall AdS/QCD

    Nick Evans🇬🇧 · Jack Mitchell🇬🇧

    We construct a new holographic description of QCD using domain wall fermions. The construction consists of probe D7 branes in a D5 brane geometry describing quarks on a 4+1d defect in a 5+1d gauge theory. We then compactify one dimension of the D5 to introduce confinement in the gauge degrees of freedom. In addition we allow a spatial dependent mass term for the D7 brane quarks to isolate chiral fermions on 3+1d domain walls. The D7 world volume fields, when restricted to the domain wall position, provide an AdS/QCD description. We compute the spectrum and compare to data. We include higher dimension operators to systematically improve the description.

    ↳ hep-thhep-phPRD(2021)·6 citations
12. 12*

    New Anisotropic Exact Solution in Multifield Cosmology

    Andronikos Paliathanasis🇿🇦

    In the case of two-scalar field cosmology and, specifically for the Chiral model, we determine an exact solution for the field equations with a anisotropic background space. The exact solution can describe anisotropic inflation with a Kantowski-Sachs geometry and it can be seen as the anisotropic analogue of the hyperbolic inflation. Finally, we investigate the evolution for the homogeneous perturbations around the new asymptotic solution.

    ↳ gr-qchep-phUniverse(2021)·7 citations
13. 13*

    A New Generation of Neutrino Cross Section Experiments: Challenges and Opportunities

    A. Branca🇮🇹 · G. Brunetti🇮🇹 · A. Longhin🇮🇹 · M. Martini🇫🇷 · F. Pupilli🇮🇹 · F. Terranova🇮🇹

    Our knowledge of neutrino cross sections at the GeV scale, instrumental to test CP symmetry violation in the leptonic sector, has grown substantially in the last two decades. Still, their precision and understanding are far from the standard needed in contemporary neutrino physics. Nowadays, the knowledge of the neutrino cross-section at $O(10\%)$ causes the main systematic uncertainty in oscillation experiments and jeopardizes their physics reach. In this paper, we envision the opportunities for a new generation of cross section experiments to be run in parallel with DUNE and HyperKamiokande. We identify the most prominent physics goals by looking at the theory and experimental limitations of the previous generation of experiments. We highlight the priorities in the theoretical understanding of GeV cross-sections and the experimental challenges of this new generation of facilities.

    ↳ hep-exhep-phphysics.acc-phSymmetry(2021)·20 citations
14. 14*

    QCD Factorization and Quantum Mechanics

    C. A. Aidala🇺🇸 · T. C. Rogers🇺🇸

    It is unusual to find QCD factorization explained in the language of quantum information science. However, we will discuss how the issue of factorization and its breaking in high-energy QCD processes relates to phenomena like decoherence and entanglement. We will elaborate with several examples and explain them in terms familiar from basic quantum mechanics and quantum information science.

    ↳ quant-phhep-phnucl-thPhil.Trans.A.Math.Phys.Eng.Sci.(2021)·7 citations
15. 15*

    Measurement of lepton-jet correlation in deep-inelastic scattering with the H1 detector using machine learning for unfolding

    H1 Collaboration: V. Andreev (23)🇷🇺 · M. Arratia (36)🇺🇸 · A. Baghdasaryan (47)🇦🇲 · A. Baty (16)🇺🇸 · K. Begzsuren (40)🇲🇳 · A. Belousov (23)🇷🇺 · A. Bolz (13)🇩🇪 · V. Boudry (32)🇫🇷 · G. Brandt (12)🇩🇪 · D. Britzger (26)🇩🇪 · A. Buniatyan (6)🇬🇧 · L. Bystritskaya (22)🇷🇺 and 132 other authors

    The first measurement of lepton-jet momentum imbalance and azimuthal correlation in lepton-proton scattering at high momentum transfer is presented. These data, taken with the H1 detector at HERA, are corrected for detector effects using an unbinned machine learning algorithm OmniFold, which considers eight observables simultaneously in this first application. The unfolded cross sections are compared to calculations performed within the context of collinear or transverse-momentum-dependent (TMD) factorization in Quantum Chromodynamics (QCD) as well as Monte Carlo event generators. The measurement probes a wide range of QCD phenomena, including TMD parton distribution functions and their evolution with energy in so far unexplored kinematic regions.

    ↳ hep-exhep-phPRL(2022)·97 citations
16. 16*

    Rotating Kerr-Newman space-times in Metric-Affine Gravity

    Sebastian Bahamonde🇪🇪 · Jorge Gigante Valcarcel🇪🇪

    We present new rotating vacuum configurations endowed with both dynamical torsion and nonmetricity fields in the framework of Metric-Affine gauge theory of gravity. For this task, we consider scalar-flat Weyl-Cartan geometries and obtain an axisymmetric Kerr-Newman solution in the decoupling limit between the orbital and the spin angular momentum. The corresponding Kerr-Newman-de Sitter solution is also compatible with a cosmological constant and additional electromagnetic fields.

    ↳ gr-qcastro-ph.HEhep-phJCAP(2022)·16 citations
17. 17*

    Finite-density lattice QCD and sign problem: current status and open problems

    Keitaro Nagata🇯🇵

    This an English translation of a review of finite-density lattice QCD. The original version in Japanese appeared in Soryushiron Kenkyu Vol 31 (2020) No. 1.

    ↳ hep-lathep-phhep-thnucl-thPPNP(2022)·233 citations
18. 18*

    Pions in Proton Structure and Everywhere Else

    Mary Alberg (1,2)🇺🇸 · Lucas Ehinger (1)🇺🇸 · Gerald A. Miller (2) ((1) Seattle University, (2) University of Washington)🇺🇸

    The pion cloud is important in nuclear physics and in a variety of low-energy hadronic phenomena. We argue that it is natural to expect it to also be important in lepton-proton deep inelastic scattering and Drell-Yan studies of proton structure. We compute the necessary consequences of the pion cloud in connection with the recent SeaQuest data. The effects are detailed by using the exact kinematics of the experiment. Good agreement with the measurements is obtained. Thus the universality of pionic effects is understood.

    ↳ nucl-thhep-phPRD(2022)·12 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.