Mon·Jun 26, 2023Monday·June 26, 2023

1. 01*

   Predictions for Muon Electric and Magnetic Dipole Moments from $h\to {\mu }^{+}{\mu }^{-}$ in Two-Higgs-Doublet Models with New Leptons

   Radovan Dermisek🇺🇸 · Keith Hermanek🇺🇸 · Navin McGinnis🇨🇦 · Sangsik Yoon🇺🇸

   We calculate chirally enhanced corrections to the muon's electric and magnetic dipole moments in two-Higgs-doublet models extended by vector-like leptons, and we explore a sharp correlation between $h\to {\mu }^{+}{\mu }^{-}$ and the muon's dipole moments in these models. Among many detailed predictions, for a model with new leptons with the same quantum numbers as standard model leptons, we find that $0.38\lesssim \tan \beta \lesssim 21$ necessarily requires a muon electric dipole moment to be observed at near-future experiments, assuming $h\to {\mu }^{+}{\mu }^{-}$ is measured within $1\%$ of the standard model prediction for the current central value of the measured muon magnetic moment. In all studied models, the predicted values of the electric dipole moment can reach up to current experimental limits. Moreover, we show that in some models there can be two sources of chiral enhancement, parametrizing the correlation between $h\to {\mu }^{+}{\mu }^{-}$ and the dipole moments by a complex number. This leads to sign-preferred predictions for the electric dipole moment.

   hep-phPRD(2023)·12 citations
2. 02*

   Modified trimaximal mixing for solar and reactor neutrino mixing angles

   Yulin Chen🇯🇵 · Yuta Hyodo🇯🇵 · Teruyuki Kitabayashi🇯🇵

   The trimaximal mixing scheme is one of the widely studied neutrino mixing schemes. However, the predicted solar neutrino mixing angle ${\theta }_{12}$ and the reactor neutrino mixing angle ${\theta }_{13}$ cannot simultaneously realize their best-fit values. To address this issue, a minimal modification to the trimaximal mixing scheme is proposed. The modified trimaximal mixing scheme can simultaneously predict the best-fit values of ${\theta }_{12}$ and ${\theta }_{13}$ using an additional real parameter introduced via the modification.

   hep-phInt.J.Mod.Phys.A(2023)·4 citations
3. 03*

   Studying the mass sensitivity of air-shower observables using simulated cosmic rays

   Benjamin Flaggs🇺🇸 · Alan Coleman🇺🇸 · Frank G. Schröder🇺🇸

   Using CORSIKA simulations, we investigate the mass sensitivity of cosmic-ray air-shower observables for sites at the South Pole and Malargüe, Argentina, the respective locations of the IceCube Neutrino Observatory and the Pierre Auger Observatory. Exact knowledge of observables from air-shower simulations was used to study the event-by-event mass separation between proton, helium, oxygen, and iron primary cosmic rays with a Fisher linear discriminant analysis. Dependencies on the observation site as well as the energy and zenith angle of the primary particle were studied in the ranges from $10^{16.0}-10^{18.5}$eV and $0^{\circ }$ to $60^{\circ }$: they are mostly weak and do not change the qualitative results. Promising proton-iron mass separation is achieved using combined knowledge of all studied observables, also when typical reconstruction uncertainties are accounted for. However, even with exact measurements, event-by-event separation of intermediate-mass nuclei is challenging and better methods than the Fisher discriminant and/or the inclusion of additional observables will be needed. As an individual observable, high-energy muons ($>500$GeV) provide the best event-by-event mass discrimination, but the combination of muons of any energy and $X_{\text{max}}$ provides already a high event-by-event separation between proton-iron primaries at both sites. We also confirm that the asymmetry and width parameters of the air-shower longitudinal profile, $R$ and $L$, are mass sensitive. Only $R$ seems to be suitable for event-by-event mass separation, but $L$ can potentially be used to statistically determine the proton-helium ratio. Overall, our results motivate the coincident measurement of several air-shower observables, including at least $X_{\text{max}}$ and the sizes of the muonic and electromagnetic shower components, for the next generation of air-shower experiments.

   hep-phastro-ph.HEastro-ph.IMPRD(2024)·18 citations
4. 04*

   Disoriented isospin condensates may be the source of anomalous kaon correlations measured in Pb-Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV

   Joseph I. Kapusta🇺🇸 · Scott Pratt🇺🇸 · Mayank Singh🇺🇸

   The magnitude of fluctuations between charged and neutral kaons measured by the ALICE Collaboration in heavy-ion collisions at the LHC exceeds conventional explanation. Here it is shown that if the scalar condensate, which is typically associated with chiral symmetry, is accompanied by an isospin=1 field, then the combination can produce large fluctuations where $⟨\bar{u}u⟩\ne ⟨\bar{d}d⟩$. Hadronizing strange and anti-strange quarks might then strongly fluctuate between charged ($u\bar{s}$ or $s\bar{u}$) and neutral ($d\bar{s}$ or $s\bar{d}$) kaons.

   hep-phnucl-thPRC(2024)·10 citations
5. 05*

   Searching for GUT-scale QCD Axions and Monopoles with a High Voltage Capacitor

   Michael E. Tobar🇦🇺 · Anton V. Sokolov🇬🇧 · Andreas Ringwald🇩🇪 · Maxim Goryachev🇦🇺

   The QCD axion has been postulated to exist because it solves the strong CP problem. Furthermore, if it exists axions should be created in the early Universe and could account for all the observed dark matter. In particular, axion masses of order $10^{-10}$ to $10^{-7}$ eV correspond to axions in the vicinity of the GUT-scale. In this mass range many experiments have been proposed to search for the axion through the standard QED coupling parameter $g_{a\gamma \gamma }$. Recently axion electrodynamics has been expanded to include two more coupling parameters, $g_{aEM}$ and $g_{aMM}$, which could arise if heavy magnetic monopoles exist. In this work we show that both $g_{aMM}$ and $g_{aEM}$ may be searched for using a high voltage capacitor. Since the experiment is not sensitive to $g_{a\gamma \gamma }$, it gives a new way to search for effects of heavy monopoles if the GUT-scale axion is shown to exist, or to simultaneously search for both the axion and the monopole at the same time.

   hep-phastro-ph.IMgr-qcphysics.ins-detPRD(2023)·13 citations
6. 06*

   Constraining Dark Photons with Self-consistent Simulations of Globular Cluster Stars

   Matthew J. Dolan🇦🇺 · Frederick J. Hiskens🇦🇺 · Raymond R. Volkas🇦🇺

   We revisit stellar constraints on dark photons. We undertake dynamical stellar evolution simulations which incorporate the resonant and off-resonant production of transverse and longitudinal dark photons. We compare our results with observables derived from measurements of globular cluster populations, obtaining new constraints based on the luminosity of the tip of the red-giant branch (RGB), the ratio of populations of RGB to horizontal branch (HB) stars (the $R$-parameter), and the ratio of asymptotic giant branch to HB stars (the $R_2$-parameter). We find that previous bounds derived from static stellar models do not capture the effects of the resonant production of light dark photons leading to overly conservative constraints, and that they over-estimate the effects of heavier dark photons on the RGB-tip luminosity. This leads to differences in the constraints of up to an order of magnitude in the kinetic mixing parameter.

   hep-phastro-ph.SRJCAP(2024)·29 citations
7. 07*

   Gravitational Interaction of Ultralight Dark Matter with Interferometers

   Hyungjin Kim🇩🇪

   Ultralight dark matter exhibits an order-one density fluctuation over the spatial scale of its wavelength. These fluctuations gravitationally interact with gravitational wave interferometers, leading to distinctive signals in detectors. We investigate the ultralight dark matter-induced effects in the gravitational wave interferometers. We perform a systematic computation of the power spectrum of ultralight dark matter in interferometers. We show that the ultralight dark matter-induced effect is most relevant for the interferometers with long baseline and that it is only a sub-leading effect compared to the estimated noise level in the case of Laser Interferometer Space Antenna or future interferometers with an arm-length comparable to a few astronomical units. Gravitational wave interferometers can then place upper limits on the ultralight dark matter density in the solar system. We find that, under certain assumptions, future interferometers with AU-scale arm-length might probe the dark matter density a few hundred times the local dark matter density, which is measured over a much larger spatial scale.

   hep-phastro-ph.GAgr-qcJCAP(2023)·43 citations
8. 08*

   Two-loop corrections to Lamb shift and hyperfine splitting in hydrogen via multi-loop methods

   Petr A. Krachkov🇷🇺 · Roman N. Lee🇷🇺

   We revisit the contributions of order ${\alpha }^2(Z\alpha {)}^{5}m$ and ${\alpha }^2(Z\alpha )E_F$, respectively, to the Lamb shift and to the hyperfine splitting from mixed self-energy-vacuum-polarization diagrams, involving fermionic loop. We use modern multi-loop calculation techniques based on IBP reduction and differential equations. We construct the $ϵ$-regular basis [LeeOnishchenko2019] and explicitly demonstrate that it is compatible with the renormalization. We obtain analytic results in terms of one-fold integral involving elliptic function and dilogarithm. As a by-product, we obtain the analogous contribution for the limiting cases of heavy and light fermionic loop.

   hep-phphysics.atom-phJHEP(2023)·3 citations
9. 09*

   Constraints on the dark sector from electroweak precision observables

   B. M. Loizos🇦🇺 · X. G. Wang🇦🇺 · A. W. Thomas🇦🇺 · M. J. White🇦🇺 · A. G. Williams🇦🇺

   We revisit the Standard Model fit to electroweak precision observables using the latest data and the Particle Data Group value of the mass of the W boson. This analysis is repeated for the value reported by CDF. The constraints on the parameter space for dark photons arising from these electroweak precision observables are then evaluated for both values of the W boson mass. We also extend previous work by placing the first electroweak precision observable constraints on the coupling of dark photons to the fermionic dark matter sector.

   hep-phhep-exJ.Phys.G(2024)·18 citations
10. 10*

    Complete NLO corrections to off-shell $\text{t}\overline{\text{t}}\text{Z}$ production at the LHC

    Ansgar Denner🇩🇪 · Daniele Lombardi🇩🇪 · Giovanni Pelliccioli🇩🇪

    Measuring precisely top-pair-associated processes at hadron colliders will become possible with the upcoming LHC running stages. The increased data statistics will especially enable differential measurements leading to an improved characterisation of such processes. Aiming at a consistent data-theory comparison, precise Standard-Model predictions are needed, including higher-order corrections and full off-shell effects. In this work we present NLO-accurate predictions for the production and decay of a top-antitop pair in association with a Z boson at the LHC, in the multi-lepton decay channel. The complete set of LO contributions and NLO corrections of EW and QCD origin is included. The calculation is based on full matrix elements, computed with all resonant and non-resonant contributions, complete spin correlations and interference effects. Integrated and differential cross-sections are presented for a realistic fiducial setup.

    hep-phhep-exJHEP(2023)·17 citations
11. 11*

    Asymmetric Dark Matter From Scattering

    Deep Ghosh🇮🇳

    In dark matter (DM) cosmology, the central question is how the present-day density of DM is generated from some initial conditions in the early universe. Different production mechanisms of DM are instrumental in probing DM microphysics in current and future experiments and observations. In this context, thermal dark matter is historically most-studied scenario, in which DM is thermalized with the visible sector in the early universe. Thermalized DM sector is described by visible sector temperature and a chemical potential in general. In particular, a non-zero chemical potential of DM indicates a difference (asymmetry) between particle-antiparticle number densities in the dark sector. In this work, we have studied the generation of DM chemical potential only from DM scatterings and their interplay in the early universe, consequently its effect on the present-day density and the composition of DM.

    hep-ph1 citation
12. 12*

    All in the Family: the quintessential kinship between Inflation and Dark Energy

    P. Q. Hung🇺🇸

    A unified dynamical model of dark energy and inflation is presented, in which both phenomena are driven by axion-like fields-quintessences-of spontaneously broken global $U(1{)}_A$'s symmetries whose potentials are induced by instantons of the QCD gauge group $SU(3{)}_c$ for inflation and of a new strongly interacting gauge group $SU(2{)}_Z$ for dark energy. It is shown that $SU(3{)}_c$ and $SU(2{)}_Z$ fit snugly into a unified gauge group $SU(5{)}_Z$, {\em Ischyr$\acute{o}$s Unification Theory} or {\em IUT}, which is spontaneously broken down to $SU(3{)}_c\times SU(2{)}_Z\times U(1{)}_X$. A judicious choice of $SU(5{)}_Z$ representations leads to the $SU(3{)}_c$ and $SU(2{)}_Z$ couplings growing strong at ${\Lambda }_{QCD}\sim 200\text{mev}$ and ${\Lambda }_Z\sim 10^{-3}eV$ respectively. The model predicts particles carrying $SU(2{)}_Z$ quantum numbers which can be searched for at colliders such as the LHC and which, as a result, might indirectly reveal the nature of dark energy and perhaps inflation in a laboratory. In addition, the fermionic spectrum of the model contains a possible candidate for dark matter.

    hep-phastro-ph.CO1 citation
13. 13*

    Dirac leptogenesis via scatterings

    Julian Heeck🇺🇸 · Jan Heisig🇩🇪 · Anil Thapa🇺🇸

    Leptogenesis typically requires the introduction of heavy particles whose out-of-equilibrium decays are essential for generating a matter-antimatter asymmetry, according to one of Sakharov's conditions. We show that in Dirac leptogenesis, scatterings between the light degrees of freedom - Standard Model particles plus Dirac neutrinos - suffice to generate the asymmetry. Sakharov's conditions are satisfied because the right-handed neutrino partners are out of equilibrium. Consequently, heavy degrees of freedom never needed to be produced in the early universe, allowing for a reheating temperature below their mass scale. We solve the Boltzmann equations and discuss the viable parameter space together with observational signatures such as an increased number of effective neutrinos in the early universe as well as proton decay for some realizations.

    hep-phPRD(2023)·1 citation
14. 14*

    Transmission of vortex electrons through a solenoid

    G.K. Sizykh🇷🇺 · A.D. Chaikovskaia🇷🇺 · D.V. Grosman🇷🇺 · I.I. Pavlov · D.V. Karlovets🇷🇺

    We argue that it is generally nonstationary Laguerre-Gaussian states (NSLG) rather than the Landau ones that appropriately describe electrons with orbital angular momentum both in their dynamics at a hard-edge boundary between a solenoid and vacuum and inside the magnetic field. It is shown that the r.m.s. radius of the NSLG state oscillates in time and its period-averaged value can significantly exceed the r.m.s. radius of the Landau state, even far from the boundary. We propose to study the unconventional features of quantum dynamics inside a solenoid in several experimental scenarios with vortex electrons described by the NSLG states. Relevance for processes in scanning and transmission electron microscopes, as well as for particle accelerators with relativistic beams is emphasized.

    ↳ quant-phhep-phphysics.acc-phphysics.opticsPRA(2024)·16 citations
15. 15*

    Rapidity dependence of nuclear coalescence: impact on cosmic ray antinuclei

    Kfir Blum🇮🇱

    Upcoming studies at the Large Hadron Collider (LHC) aim to extend the rapidity coverage in measurements of the production cross section of antinuclei $\bar{\mathrm{d}}$ and $\overline{{}^3\mathrm{He}}$. We illustrate the impact of such studies on cosmic ray (CR) flux predictions, important, in turn, for the interpretation of results from CR experiments. We show that, in terms of the rapidity effect, covering the range $|y|<1.5$ at the LHC should be sufficient for the astrophysical CR calculation. Important extrapolation remains in other aspects of the problem, notably $\sqrt{s}$.

    ↳ astro-ph.HEhep-phnucl-thPRC(2024)·4 citations
16. 16*

    Constraining Quadratic $f(R)$ Gravity from Astrophysical Observations of the Pulsar J0704+6620

    G. G. L. Nashed🇪🇬 · Waleed El Hanafy🇪🇬

    We apply quadratic $f(R)=R+ϵR^2$ field equations, where $ϵ$ has a dimension [L${}^2$], to static spherical stellar model. We assume the interior configuration is determined by Krori-Barua ansatz and additionally the fluid is anisotropic. Using the astrophysical measurements of the pulsar PSR J0740+6620 as inferred by NICER and XMM observations, we determine $ϵ\approx \pm 3$ km${}^2$. We show that the model can provide a stable configuration of the pulsar PSR J0740+6620 in both geometrical and physical sectors. We show that the Krori-Barua ansatz within $f(R)$ quadratic gravity provides semi-analytical relations between radial, $p_r$, and tangential, $p_t$, pressures and density $\rho$ which can be expressed as $p_r\approx v_r^2(\rho -{\rho }_1)$ and $p_r\approx v_t^2(\rho -{\rho }_2)$, where $v_r$ ($v_t$) is the sound speed in radial (tangential) direction, ${\rho }_1={\rho }_s$ (surface density) and ${\rho }_2$ are completely determined in terms of the model parameters. These relations are in agreement with the best-fit equations of state as obtained in the present study. We further put the upper limit on the compactness, which satisfies the $f(R)$ modified Buchdahl limit. Interestingly, the quadratic $f(R)$ gravity with negative $ϵ$ naturally restricts the maximum compactness to values lower than Buchdahl limit, unlike the GR or $f(R)$ gravity with positive $ϵ$ where the compactness can arbitrarily approach the black hole limit $C\to 1$. The model predicts a core density a few times the saturation nuclear density ${\rho }_{\text{nuc}}=2.7\times 10^{14}$ g/cm${}^3$, and a surface density ${\rho }_s>{\rho }_{\text{nuc}}$. We provide the mass-radius diagram corresponding to the obtained boundary density which has been shown to be in agreement with other observations.

    ↳ gr-qcastro-ph.HEhep-phJCAP(2023)·8 citations
17. 17*

    Bulk viscosity from Urca processes: $npe\mu$ matter in the neutrino-transparent regime

    Mark Alford🇺🇸 · Arus Harutyunyan🇦🇲 · Armen Sedrakian🇩🇪

    We study the bulk viscosity of moderately hot and dense, neutrino-transparent relativistic $npe\mu$ matter arising from weak-interaction direct Urca processes. This work parallels our recent study of the bulk viscosity of $npe\mu$ matter with a trapped neutrino component. The nuclear matter is modeled in a relativistic density functional approach with two different parametrizations -- DDME2 (which does not allow for the low-temperature direct-Urca process at any density) and NL3 (which allows for low-temperature direct-Urca process above a low-density threshold). We compute the equilibration rates of Urca processes of neutron decay and lepton capture, as well as the rate of the muon decay, and find that the muon decay process is subdominant to the Urca processes at temperatures $T\ge 3$MeV in the case of DDME2 model and $T\ge 1$MeV in the case of NL3 model. Thus, the Urca-process-driven bulk viscosity is computed with the assumption that pure leptonic reactions are frozen. As a result the electronic and muonic Urca channels contribute to the bulk viscosity independently and at certain densities the bulk viscosity of $npe\mu$ matter shows instead of the standard one-peak (resonant) form a "flattened" shape. In the final step, we estimate the damping timescales of density oscillations by the bulk viscosity. We find that, e.g., at a typical oscillation frequency $f=1$kHz, the damping of oscillations is most efficient at temperatures $3\le T\le 5$MeV and densities $n_B\le 2n_0$ where they can affect the evolution of the post-merger object.

    ↳ nucl-thastro-ph.HEhep-phPRD(2023)·25 citations
18. 18*

    On a recent calculation of the mass spectra of quarkonia using the Cornell potential with spin-spin interactions

    Francisco M. Fernández

    We analyse a recent application of the Cornell potential with spin-spin interaction to the mass spectra of quarkonia and show that the authors have in fact used the Kratzer-Fues potential. They inadvertently converted one potential into the other by means of an invalid transformation.

    ↳ quant-phhep-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.