HEP Phenomenology·hep-ph

Mon·May 23, 2022Monday·May 23, 2022

30 papers—20 primary·10 cross-listed·reconstructed*

01*
Neutrino pair annihilation above black-hole accretion disks in modified gravity
G.Lambiase🇮🇹 · L.Mastrototaro🇮🇹
Using idealized models of the accretion disk, we investigate the effects induced by the modified theories of gravity on the annihilation of the neutrino pair annihilation into electron-positron pairs ( $ν ν ˉ \to e^{-} e^{+}$ ), occurring near the rotational axis. For the accretion disk, we have considered the models with temperature $T = co n s t an t$ and $T \propto r^{- 1}$ . In both cases, we find that the modified theories of gravity lead to an enhancement, up to more than one order of magnitude with respect to General Relativity, of the rate of the energy deposition rate of neutrino pair annihilation.
hep-phastro-ph.HEApJ(2022)·9 citations
02*
Type III Neutrino Seesaw, Freeze-In Long-Lived Dark Matter, and the $W$ Mass Shift
Ernest Ma (UC Riverside)🇺🇸
In the framework of seesaw neutrino masses from heavy fermion triplets $(Σ^{+}, Σ^{0}, Σ^{-})$ , the addition of a light fermion singlet $N$ and a heavy scalar triplet $(ρ^{+}, ρ^{0}, ρ^{-})$ has some important consequences. The new particles are assumed to be odd under a new $Z_{2}$ symmetry which is only broken softly, both explicitly and spontaneously. With $N - Σ^{0}$ mixing, freeze-in long-lived dark matter through Higgs decay becomes possible. At the same time, the $W$ mass is shifted slightly upward, as suggested by a recent precision measurement.
hep-phPLB(2022)·9 citations
03*
Searching for Muonphilic Dark Sectors with Proton Beams
Claudia Rella🇨🇭 · Babette Döbrich🇨🇭 · Tien-Tien Yu🇺🇸
Proton beam-dump experiments are a high-intensity source of secondary muons and provide an opportunity to probe muon-specific dark sectors. We adopt a simplified-models framework for an exotic light scalar particle coupling predominantly or exclusively to muons. Equipped with state-of-the-art muon simulations, we compute the sensitivity reach in the parameter space $(m_{S}, g_{μ})$ of the dark mediator, examining in detail the examples of the experiment NA62 in beam-dump mode and the proposed experiment SHiP. We find a significant yield of such exotics in the sub-GeV mass range. Our projections are competitive with those of primary muon-beam experiments and complementary to current constraints, spanning uncharted parameter space and accessing new physics potentially responsible for the $(g - 2)_{μ}$ anomaly.
hep-phhep-exPRD(2022)·24 citations
04*
Hunting for vampires and other unlikely forms of parity violation at the Large Hadron Collider
Christopher G. Lester🇬🇧 · Radha Mastandrea🇺🇸 · Daniel Noel🇬🇧 · Rupert Tombs🇬🇧
Non-Standard-Model parity violation may be occurring in LHC collisions. Any such violation would go unseen, however, as searches are for it are not currently performed. One barrier to searches for parity violation is the lack of model-independent methods sensitive to all of its forms. We remove this barrier by demonstrating an effective and model-independent way to search for parity-violating physics at the LHC. The method is data-driven and makes no reference to any particular parity-violating model. Instead, it inspects data to construct sensitive parity-odd event variables (using machine learning tools), and uses these variables to test for parity asymmetry in independent data. We demonstrate the efficacy of this method by testing it on data simulated from the Standard Model and from a non-standard parity-violating model. This result enables the possibility of investigating a variety of previously unexplored forms of parity violation in particle physics. Data and software are shared at https://zenodo.org/record/6827724
hep-phJHEP(2022)·7 citations
05*
Pion Polarizability 2022 Status Report
Murray Moinester🇮🇱
The electric $α_{π}$ and magnetic $β_{π}$ charged pion Compton polarizabilities are of fundamental interest in the low-energy sector of quantum chromodynamics (QCD). They characterize the induced dipole moments of the pion during $γ π$ Compton scattering. Pion polarizabilities affect the shape of the $γ π$ Compton scattering angular distribution.The combination $(α_{π} - β_{π})$ was measured by: (1) CERN COMPASS via $π Z \to π Z γ$ radiative pion Primakoff scattering in the nuclear Coulomb field, (2) SLAC PEP Mark-II via two-photon production of pion pairs, $γ γ \to π^{+} π^{-}$ , and (3) Mainz Microtron MAMI via radiative pion photoproduction from the proton, $γ p \to γ π^{+} n$ . Ongoing and planned pion polarizability experiments (CERN COMPASS, BESIII at Beijing, JLab at Newport News) are also described. The Mark-II pion polarizability 95% confidence interval is approximately $0 - 11 \times 1 0^{- 4} f m^{3}$ , based on $(α_{π} - β_{π}) = (4.4 \pm 3.2) \times 1 0^{- 4} f m^{3}$ . The Mainz value $(α_{π} - β_{π}) = 11.6 \times 1 0^{- 4} f m^{3}$ is excluded on the basis of a dispersion relations calculation which uses the Mainz value as input, and gives significantly too large $γ γ \to π^{0} π^{0}$ cross sections compared to DESY Crystal Ball data. To date, only the COMPASS polarizability measurement has acceptably small uncertainties. Its value $(α_{π} - β_{π}) = (4.0 \pm 1.8) \times 1 0^{- 4} f m^{3}$ agrees well with the two-loop ChPT prediction $(α_{π} - β_{π}) = (5.7 \pm 1.0) \times 1 0^{- 4} f m^{3}$ , thereby strengthening the identification of the pion with the Goldstone boson of QCD.
hep-phhep-ex9 citations
06*
$C P$ structure of the top-quark Yukawa interaction: NLO QCD corrections and off-shell effects
Jonathan Hermann🇩🇪 · Daniel Stremmer🇩🇪 · Malgorzata Worek🇩🇪
Since its discovery at the Large Hadron Collider in 2012 the Higgs boson has arguably become the most famous of the Standard Model particles and many measurements have been performed in order to assess its properties. Among others, these include measurements of the Higgs boson's $C P$ state which is predicted to be $C P$ -even. Even though a pure $C P$ -odd state has been ruled out, a possible admixture of a $C P$ -odd Higgs state has yet to be excluded. In this work we present predictions for the associated production of a leptonically decaying top quark pair and a stable Higgs boson $pp \to e^{+} ν_{e} μ^{-} ν ˉ_{μ} b b ˉ H$ with possible mixing between $C P$ -even and $C P$ -odd states at NLO in QCD for the LHC with $s = 13$ TeV. Finite top-quark and gauge boson width effects as well as all double-, single- and non-resonant Feynman diagrams including their interference effects are taken into account. We compare the behaviour of the $C P$ -even, -odd and -mixed scenarios for the integrated fiducial cross-sections as well as several key differential distributions. In addition, we show that both NLO corrections and off-shell effects play an important role even at the level of integrated fiducial cross-sections and that these are further enhanced in differential distributions. Even though we focus here on the Standard Model Higgs boson, the calculations could be straightforwardly applied to models that have an extended Higgs-boson sector and predict the existence of $C P$ -odd Higgs-like particles, such as the two-Higgs-doublet model.
hep-phhep-exJHEP(2022)·17 citations
07*
Effects of variations of SUSY breaking scale on neutrino parameters at low energy scale under radiative corrections
Kh. Helensana Devi🇮🇳 · K. Sashikanta Singh🇮🇳 · N.Nimai Singh🇮🇳
The paper addresses the effects of the variations of the SUSY breaking scale $m_{s}$ in the range (2-14) TeV on the three neutrino masses and mixings, in running the renormalization group equations (RGEs) for different input values of high energy seesaw scale $M_{R}$ , in both normal and inverted hierarchical neutrino mass models. The present investigation is a continuation of the earlier works based on the variation of $m_{s}$ scale. Two approaches are adopted one after another - bottom-up approach for running gauge and Yukawa couplings from low to high energy scale, followed by the top-down approach from high to low energy scale for running neutrino parameters defined at high energy scale, along with gauge and Yukawa couplings. A self-complementarity relation among three mixing angles is also employed in the analysis. Significant effect due to radiative corrections on neutrino parameters with the variation of SUSY breaking scale $m_{s}$ , is observed.
hep-phAdv.High Energy Phys.(2022)·2 citations
08*
Ratio of baryon and electric-charge cumulants at second order with acceptance corrections
Masakiyo Kitazawa🇯🇵 · ShinIchi Esumi🇯🇵 · Toshihiro Nonaka🇯🇵
We evaluate the ratio of baryon and electric-charge cumulants at second order from the recent experimental results at $s_{_{N N}} = 200$ GeV by the STAR Collaboration. The baryon number cumulant is reconstructed from the proton number distribution, and effects of the finite acceptance on the transverse momentum are corrected assuming the independent particle emission. We show that the obtained ratio has a dependence on the rapidity window. Comparison of the result with the hadron resonance gas model and lattice QCD numerical simulations suggests that if the fluctuations are generated from a thermal medium its temperature is significantly lower than the chemical freezeout temperature.
hep-phnucl-exnucl-thNPA(2023)·4 citations
09*
Theoretical summary of Moriond 2022: QCD and high-energy interactions
Kirill Melnikov🇩🇪
I review theoretical talks presented at the session on QCD and high-energy interactions of the Moriond 2022 conference.
hep-ph0 citations
10*
A Global Analysis of Resonance-enhanced Light Scalar Dark Matter
Tobias Binder🇯🇵 · Sreemanti Chakraborti🇫🇷 · Shigeki Matsumoto🇯🇵 · Yu Watanabe🇯🇵
We study a minimal model for a light scalar dark matter, requiring a light scalar mediator to address the core-cusp problem and interact with the standard model particles. We analyze the model comprehensively by focusing on the Breit-Wigner resonance for dark matter annihilation and self-scattering channels, considering the thermal relic abundance condition that includes the early kinetic decoupling effect, as well as the present and future constraints from collider, direct, and indirect dark matter detections. We found that the scalar dark matter with the mass of 0.3-2 GeV remains uncharted, which will be efficiently tested by the near future MeV gamma-ray observations.
hep-phJHEP(2023)·23 citations
11*
Axion and FIMP Dark Matter in a $U (1)$ extension of the Standard Model
Laura Covi🇩🇪 · Sarif Khan🇩🇪
In the Standard Model a Dark Matter candidate is missing, but it is relatively simple to enlarge the model including one or more suitable particles. We consider in this paper one such extension, inspired by simplicity and by the goal to solve more than just the Dark Matter issue. Indeed we consider a local $U (1)$ extension of the SM providing an axion particle to solve the strong CP problem and including RH neutrinos with appropriate mass terms. One of the latter is decoupled from the SM leptons and can constitute stable sterile neutrino DM. In this setting, the PQ symmetry arises only as an accidental symmetry but its breaking by higher order operators is sufficiently suppressed to avoid introducing a large $θ$ contribution. The axion decay constant and the RH neutrino masses are related to the same v.e.v.s and the PQ scale and both DM densities are determined by the parameters of the axion and scalar sector. The model predicts in general a mixed Dark Matter scenario with both axion and sterile neutrino DM and is characterised by a reduced density and observational signals from each single component.
hep-phJCAP(2022)·6 citations
12*
On the Cosmological Stability of the Higgs Instability
Valerio De Luca🇨🇭 · Alex Kehagias🇬🇷 · Antonio Riotto🇨🇭
The Standard Model Higgs potential becomes unstable at large Higgs field values where its quartic coupling becomes negative. While the tunneling lifetime of our current electroweak vacuum is comfortably longer than the age of the universe, quantum fluctuations during inflation might push the Higgs over the barrier, forming patches which might be lethal for our universe. We study the cosmological evolution of such regions and find that, at least in the thin wall approximation, they may be harmless as they collapse due to the backreaction of the Higgs itself. The presence of the Standard Model Higgs instability can provide a novel mechanism to end inflation and to reheat the universe through the evaporation of the black holes left over by the collapse of the Higgs bubbles. The bound on the Hubble rate during inflation may be therefore relaxed.
hep-phastro-ph.COgr-qchep-thJCAP(2022)·19 citations
13*
Response of a baryon-charged medium to energetic partons
Lipei Du (McGill U., Ohio State U.)🇨🇦 · Ulrich Heinz (Ohio State U.)🇺🇸
We explore the response to energetic partons of a baryon-charged medium produced in low energy heavy-ion collisions in which the partonic energy loss rate is expected to depend on both temperature and baryon chemical potential. The energy and momentum deposited by the partons are described by dynamical sources added to hydrodynamic equations of motion. We study the distortions of various hydrodynamic quantities, especially the energy and baryon densities, induced by energetic partons plowing through the medium. By studying the contribution from this medium response to the emission spectra of several identified hadron species we identify qualitative differences between the jet-induced modifications for mesons and net protons.
hep-phnucl-thPRC(2022)·7 citations
14*
First extraction of inclusive $V_{c b}$ from $q^{2}$ moments
Florian Bernlochner🇩🇪 · Matteo Fael🇩🇪 · Kevin Olschewsky🇩🇪 · Eric Persson🇩🇪 · Raynette van Tonder🇨🇦 · K. Keri Vos🇳🇱 · Maximilian Welsch🇩🇪
We present the first determination of $V_{c b}$ from inclusive $B \to X_{c} ℓ ν ˉ_{ℓ}$ using moments of the dilepton invariant mass, $q^{2}$ . These moments are reparametrization invariant quantities and depend on a reduced set of non-perturbative parameters. This reduced opens a new path to extract these parameters up to $1/ m_{b}^{4}$ purely from data and thereby reducing the uncertainty on $V_{c b}$ . In this paper, we present our first determination of $V_{c b}$ using this method. Combining the recent measurements of $q^{2}$ moments by Belle and Belle II, our default fit gives $∣ V_{c b} ∣ = (41.69 \pm 0.63) \cdot 1 0^{- 3}$ . This results presents an important independent cross check of, and is consistent with, the previous state-of-the-art inclusive determinations using lepton energy and hadronic invariant mass moments.
hep-phJHEP(2022)·112 citations
15*
Heavy quarkonium dynamics at next-to-leading order in the binding energy over temperature
Nora Brambilla🇩🇪 · Miguel Ángel Escobedo🇪🇸 · Ajaharul Islam🇺🇸 · Michael Strickland🇺🇸 · Anurag Tiwari🇺🇸 · Antonio Vairo🇩🇪 · Peter Vander Griend🇩🇪
Using the potential non-relativistic quantum chromodynamics (pNRQCD) effective field theory, we derive a Lindblad equation for the evolution of the heavy-quarkonium reduced density matrix that is accurate to next-to-leading order (NLO) in the ratio of the binding energy of the state to the temperature of the medium. The resulting NLO Lindblad equation can be used to more reliably describe heavy-quarkonium evolution in the quark-gluon plasma at low temperatures compared to the leading-order truncation. For phenomenological application, we numerically solve the resulting NLO Lindblad equation using the quantum trajectories algorithm. To achieve this, we map the solution of the three-dimensional Lindblad equation to the solution of an ensemble of one-dimensional Schrödinger evolutions with Monte-Carlo sampled quantum jumps. Averaging over the Monte-Carlo sampled quantum jumps, we obtain the solution to the NLO Lindblad equation without truncation in the angular momentum quantum number of the states considered. We also consider the evolution of the system using only the complex effective Hamiltonian without stochastic jumps and find that this provides a reliable approximation for the ground state survival probability at LO and NLO. Finally, we make comparisons with our prior leading-order pNRQCD results and experimental data available from the ATLAS, ALICE, and CMS collaborations.
hep-phnucl-exnucl-thphysics.comp-phJHEP(2022)·59 citations
16*
Dark Z at the International Linear Collider
Yik Chuen San🇺🇸 · Maxim Perelstein🇺🇸 · Philip Tanedo🇺🇸
A dark Z is a massive Abelian gauge boson which is coupled to the Standard Model through both kinetic and mass mixing with the electroweak sector. We study the phenomenology of the dark Z at an energy-frontier electron-positron collider, such as the proposed International Linear Collider (ILC). We show that precision electroweak constraints and the current bounds from the hadron colliders allow a dark Z that is kinematically accessible at the ILC with 250 GeV or 500 GeV center-of-mass energy. Further, the reach of the ILC searches for a dark Z significantly exceeds the expected reach of the high luminosity LHC. If a signal consistent with a dark Z is discovered, it would motivate a dedicated run of the ILC at the center-of-mass energy matching the dark Z mass. We demonstrate that a short one month run at design luminosity could measure the dark Z chiral couplings to fermions with percent precision. This measurement can be used to discriminate between competing theoretical models of the resonance: for example, the dark Z can be distinguished from a dark photon with purely kinetic mixing.
hep-phPRD(2022)·17 citations
17*
The complex heavy-quark potential in an anisotropic quark-gluon plasma -- Statics and dynamics
Lihua Dong🇨🇳 · Yun Guo🇨🇳 · Ajaharul Islam🇺🇸 · Alexander Rothkopf🇳🇴 · Michael Strickland🇺🇸
We generalize a complex heavy-quark potential model from an isotropic QCD plasma to an anisotropic one by replacing the Debye mass $m_{D}$ with an anisotropic screening mass depending on the quark pair alignment with respect to the direction of anisotropy. Such an angle-dependent mass is determined by matching the perturbative contributions in the potential model to the exact result obtained in the Hard-Thermal-Loop resummed perturbation theory. An advantage of the resulting potential model is that its angular dependence can be effectively described by using a set of angle-averaged screening masses as proposed in our previous work. Consequently, one could solve a one-dimensional Schrödinger equation with a potential model built by changing the anisotropic screening masses into the corresponding angle-averaged ones, and reproduce the full three-dimensional results for the binding energies and decay widths of low-lying quarkonium bound states to very high accuracy. Finally, turning to dynamics, we demonstrate that the one-dimensional effective potential can accurately describe the time evolution of the vacuum overlaps obtained using the full three-dimensional anisotropic potential. This includes the splitting of different p-wave polarizations.
hep-phJHEP(2022)·23 citations
18*
Self-supervised Anomaly Detection for New Physics
Barry M. Dillon🇩🇪 · Radha Mastandrea🇺🇸 · Benjamin Nachman🇺🇸
We investigate a method of model-agnostic anomaly detection through studying jets, collimated sprays of particles produced in high-energy collisions. We train a transformer neural network to encode simulated QCD "event space" dijets into a low-dimensional "latent space" representation. We optimize the network using the self-supervised contrastive loss, which encourages the preservation of known physical symmetries of the dijets. We then train a binary classifier to discriminate a BSM resonant dijet signal from a QCD dijet background both in the event space and the latent space representations. We find the classifier performances on the event and latent spaces to be comparable. We finally perform an anomaly detection search using a weakly supervised bump hunt on the latent space dijets, finding again a comparable performance to a search run on the physical space dijets. This opens the door to using low-dimensional latent representations as a computationally efficient space for resonant anomaly detection in generic particle collision events.
hep-phhep-exphysics.data-anPRD(2022)·44 citations
19*
Gauge Invariance and Finite Counterterms in Chiral Gauge Theories
Claudia Cornella🇩🇪 · Ferruccio Feruglio🇮🇹 · Luca Vecchi🇮🇹
We derive the finite one-loop counterterm required to restore the Ward Identities broken by the regularization scheme in chiral gauge theories. Our result is an analytic expression applicable to a wide class of regularizations satisfying a few general properties. We adopt the background field method, which ensures background gauge invariance in the quantized theory, and focus on renormalizable chiral theories with arbitrary gauge group and fermions in general representations. Our approach can be extended to theories involving scalars, such as the Standard Model, or to non-renormalizable theories, such as the SMEFT. As a concrete application, we work out the finite counterterm at one loop in the Standard Model, within dimensional regularization and the Breitenlohner-Maison-'t Hooft-Veltman prescription for $γ_{5}$ .
hep-phhep-thJHEP(2023)·33 citations
20*
Oscillations of High-Energy Cosmic Neutrinos in the Copious MeV Neutrino Background
Sajad Abbar🇩🇪 · Jose Alonso Carpio🇺🇸 · Kohta Murase🇺🇸
The core-collapse of massive stars and merger of neutron star binaries are among the most promising candidate sites for the production of high-energy cosmic neutrinos. We demonstrate that the high-energy neutrinos produced in such extreme environments can experience efficient flavor conversions on scales much shorter than those expected in vacuum, due to their coherent forward scatterings with the bath of decohered low-energy neutrinos emitted from the central engine. These low-energy neutrinos, which exist as mass eigenstates, provide a very special and peculiar dominant background for the propagation of the high-energy ones. We point out that the high-energy neutrino flavor ratio is modified to a value independent of neutrinos energies, which is distinct from the conventional prediction with the matter effect. We also suggest that the signals can be used as a novel probe of new neutrino interactions beyond the Standard Model. This is yet another context where neutrino-neutrino interactions can play a crucial role in their flavor evolution.
hep-phastro-ph.HEPRD(2024)·3 citations
21*
Exploring the effects of Delta Baryons in magnetars
K. D. Marquez🇧🇷 · M. R. Pelicer🇧🇷 · S. Ghosh🇮🇳 · J. Peterson🇺🇸 · D. Chatterjee🇮🇳 · V. Dexheimer🇺🇸 · D. P. Menezes🇧🇷
Strong magnetic fields can modify the microscopic composition of matter with consequences on stellar macroscopic properties. Within this context, we study, for the first time, the possibility of the appearance of spin-3/2 $Δ$ baryons in magnetars. We make use of two different relativistic models for the equation of state of dense matter under the influence of strong magnetic fields considering the effects of Landau levels and the anomalous magnetic moment (AMM) proportional to the spin of all baryons and leptons. In particular, we analyze the effects of the AMM of $Δ$ baryons in dense matter for the first time. {We also obtain global properties corresponding to the EoS models numerically and study the corresponding role of the $Δ$ baryons.} We find that they are favored over hyperons, which causes an increase in isopin asymmetry and a decrease in spin polarization. We also find that, contrary to what generally occurs when new degrees of freedom are introduced, the $Δ$ s do not make the EoS significantly softer and magnetars less massive. Finally, the magnetic field distribution inside a given star is not affected by the presence of $Δ$ s.
↳ astro-ph.HEhep-phnucl-thPRC(2022)·20 citations
22*
How to understand the Structure of Beta Functions in Six-derivative Quantum Gravity?
Lesław Rachwał🇧🇷
We extensively motivate the studies of higher-derivative gravities, and in particular we emphasize which new quantum features theories with six derivatives in their definitions possess. Next, we discuss the mathematical structure of the exact on the full quantum level beta functions obtained previously for three couplings in front of generally covariant terms with four derivatives (Weyl tensor squared, Ricci scalar squared and the Gauss-Bonnet scalar) in minimal six-derivative quantum gravity in $d = 4$ spacetime dimensions. The fundamental role here is played by the ratio $x$ of the coupling in front of the term with Weyl tensors to the coupling in front of the term with Ricci scalars in the original action. We draw a relation between the polynomial dependence on $x$ and the absence/presence of enhanced conformal symmetry and renormalizability in the models where formally $x \to + \infty$ in the case of four- and six-derivative theories respectively.
↳ hep-thgr-qchep-phmath-ph+2Acta Polytech.·2 citations
23*
Modelling self-interacting dark matter substructures I: Calibration with N-body simulations of a Milky-Way-sized halo and its satellite
Masato Shirasaki🇯🇵 · Takashi Okamoto🇯🇵 · Shin'ichiro Ando🇳🇱
We study evolution of single subhaloes with their masses of $\sim 1 0^{9} M_{⊙}$ in a Milky-Way-sized host halo for self-interacting dark matter (SIDM) models. We perform dark-matter-only N-body simulations of dynamical evolution of individual subhaloes orbiting its host by varying self-scattering cross sections (including a velocity-dependent scenario), subhalo orbits, and internal properties of the subhalo. We calibrate a gravothermal fluid model to predict time evolution in spherical mass density profiles of isolated SIDM haloes with the simulations. We find that tidal effects of SIDM subhaloes can be described with a framework developed for the case of collision-less cold dark matter (CDM), but a shorter typical time scale for the mass loss due to tidal stripping is required to explain our SIDM simulation results. As long as the cross section is less than $\sim 10 cm^{2} / g$ and initial states of subhaloes are set within a $2 σ$ -level scatter at redshifts of $\sim 2$ predicted by the standard $Λ$ CDM cosmology, our simulations do not exhibit a prominent feature of gravothermal collapse in the subhalo central density for 10 Gyr. We develop a semi-analytic model of SIDM subhaloes in a time-evolving density core of the host with tidal stripping and self-scattering ram pressure effects. Our semi-analytic approach provides a simple, efficient and physically-intuitive prediction of SIDM subhaloes, but further improvements are needed to account for baryonic effects in the host and the gravothermal instability accelerated by tidal stripping effects.
↳ astro-ph.COastro-ph.GAhep-phMNRAS(2022)·10 citations
24*
Instability of hairy black holes in regularized 4-dimensional Einstein-Gauss-Bonnet gravity
Shinji Tsujikawa🇯🇵
In regularized 4-dimensional Einstein-Gauss-Bonnet (EGB) gravity derived from a Kaluza-Klein reduction of higher-dimensional EGB theory, we study the existence and stability of black hole (BH) solutions on a static and spherically symmetric background. We show that asymptotically-flat hairy BH solutions realized for a spatially-flat maximally symmetric internal space are unstable against linear perturbations for any rescaled GB coupling constant. This instability is present for the angular propagation of even-parity perturbations both in the vicinity of an event horizon and at spatial infinity. There is also a strong coupling problem associated with the kinetic term of even-parity perturbations vanishing everywhere.
↳ gr-qchep-phhep-thPLB(2022)·12 citations
25*
The proton structure in and out of muonic hydrogen
Aldo Antognini (PSI, ETH Zürich)🇨🇭 · Franziska Hagelstein (JGU Mainz, PSI)🇩🇪 · Vladimir Pascalutsa (JGU Mainz)🇩🇪
Laser spectroscopy of muonic atoms has been recently used to probe properties of light nuclei with unprecedented precision. We introduce nuclear effects in hydrogen-like atoms, nucleon structure quantities (form factors, structure functions, polarizabilities) and their effects in the Lamb shift and hyperfine splitting (HFS) of muonic hydrogen ( $μ$ H). Updated theory predictions for the Lamb shift and HFS in $μ$ H are presented. We review the challenges of the ongoing effort to measure the ground-state HFS in $μ$ H and its impact on our understanding of the nucleon spin structure. To narrow down this search, we present a novel theory prediction obtained by scaling the measured HFS in hydrogen leveraging radiative corrections. We also summarize recent developments in the spectroscopy of simple atomic and molecular systems and emphasize how they allow for precise determinations of fundamental constants, bound-state QED tests and New Physics searches.
↳ nucl-thhep-phphysics.atom-phAnn.Rev.Nucl.Part.Sci.(2022)·70 citations
26*
Revisiting the Affleck-Dine mechanism for primordial black hole formation
Kentaro Kasai🇯🇵 · Masahiro Kawasaki🇯🇵 · Kai Murai🇯🇵
We study a primordial black hole (PBH) formation scenario based on the Affleck-Dine (AD) mechanism and investigate two PBH mass regions: $M \sim 30 M_{⊙}$ motivated by the LIGO-Virgo observations of the binary black hole mergers and $M ≳ 1 0^{4} M_{⊙}$ motivated by the observations of supermassive black holes at the center of galaxies. In the previous studies, it has been considered that the inhomogeneous AD baryogenesis generates regions with a large baryon asymmetry, some of which collapse into PBHs. In this paper, we show that this scenario is severely constrained due to the baryon asymmetry remaining outside PBHs, which would spoil the success of the big bang nucleosynthesis. Then, we propose an alternative scenario where the AD leptogenesis results in the inhomogeneous formation of Q-balls with lepton charges, which collapse into PBHs. As a result, we find that our scenario can explain the favorable PBH abundance without conflicting with the observational constraints.
↳ astro-ph.COhep-phJCAP(2022)·19 citations
27*
Relativistic mean-field theories for neutron-star physics based on chiral effective field theory
Mark G. Alford🇺🇸 · Liam Brodie🇺🇸 · Alexander Haber🇺🇸 · Ingo Tews🇺🇸
We describe and implement a procedure for determining the couplings of a Relativistic Mean-Field Theory (RMFT) that is optimized for application to neutron star phenomenology. In the standard RMFT approach, the couplings are constrained by comparing the theory's predictions for symmetric matter at saturation density with measured nuclear properties. The theory is then applied to neutron stars which consist of neutron-rich matter at densities ranging up to several times saturation density, which allows for additional astrophysical constraints. In our approach, rather than using the RMFT to extrapolate from symmetric to neutron-rich matter and from finite-sized nuclei to uniform matter, we fit the RMFT to properties of uniform pure neutron matter obtained from chiral effective field theory. Chiral effective field theory incorporates the experimental data for nuclei in the framework of a controlled expansion for nuclear forces valid at nuclear densities and enables us to account for theoretical uncertainties when fitting the RMFT. We construct four simple RMFTs that span the uncertainties provided by chiral effective field theory for neutron matter, and are consistent with current astrophysical constraints on the equation of state. Our RMFTs can be used to model the properties of neutron-rich matter across the vast range of densities and temperatures encountered in neutron stars and their mergers.
↳ nucl-thastro-ph.HEhep-phPRC(2022)·73 citations
28*
Tidal disruption of solitons in self-interacting ultralight axion dark matter
Noah Glennon🇺🇸 · Ethan O. Nadler🇺🇸 · Nathan Musoke🇺🇸 · Arka Banerjee🇮🇳 · Chanda Prescod-Weinstein🇺🇸 · Risa H. Wechsler🇺🇸
Ultralight axions (ULAs) are promising dark matter candidates that can have a distinct impact on the formation and evolution of structure on nonlinear scales relative to the cold, collisionless dark matter (CDM) paradigm. However, most studies of structure formation in ULA models do not include the effects of self-interactions, which are expected to arise generically. Here, we study how the tidal evolution of solitons is affected by ULA self-interaction strength and sign. Specifically, using the pseudospectral solver UltraDark.jl, we simulate the tidal disruption of self-interacting solitonic cores as they orbit a $1 0^{11} M_{⊙}$ Navarro-Frenk-White CDM host halo potential for a range of orbital parameters, assuming a fiducial ULA particle mass of $1 0^{- 22} eV$ . We find that repulsive (attractive) self-interactions significantly accelerate (decelerate) soliton tidal disruption. We also identify a degeneracy between the self-interaction strength and soliton mass that determines the efficiency of tidal disruption, such that disruption timescales are affected at the $\sim 50%$ level for variations in the dimensionless ULA self-coupling from $λ = - 1 0^{- 92}$ to $λ = 1 0^{- 92}$ .
↳ astro-ph.COhep-phPRD(2022)·30 citations
29*
Searching for Mini Extreme Mass Ratio Inspirals with Gravitational-Wave Detectors
Huai-Ke Guo🇺🇸 · Andrew Miller🇧🇪
A compact object with a mass $O (1 \sim 1000) M_{⊙}$ , such as a black hole of stellar or primordial origin or a neutron star, and a much lighter exotic compact object with a subsolar mass could form a non-standard mini extreme mass ratio inspiral (EMRI) and emit gravitational waves within the frequency band of ground-based gravitational-wave detectors. These systems are extremely interesting because detecting them would definitively point to new physics. We study the capability of using LIGO/Virgo to search for mini-EMRIs and find that a large class of exotic compact objects can be probed at current and design sensitivities using a method based on the Hough Transform that tracks quasi power-law signals during the inspiral phase of the mini-EMRI system.
↳ astro-ph.IMastro-ph.COastro-ph.HEgr-qc+118 citations
30*
Degeneracy Engineering for Classical and Quantum Annealing: A Case Study of Sparse Linear Regression in Collider Physics
Eric R. Anschuetz🇺🇸 · Lena Funcke🇺🇸 · Patrick T. Komiske🇺🇸 · Serhii Kryhin🇺🇸 · Jesse Thaler🇺🇸
Classical and quantum annealing are computing paradigms that have been proposed to solve a wide range of optimization problems. In this paper, we aim to enhance the performance of annealing algorithms by introducing the technique of degeneracy engineering, through which the relative degeneracy of the ground state is increased by modifying a subset of terms in the objective Hamiltonian. We illustrate this novel approach by applying it to the example of $ℓ_{0}$ -norm regularization for sparse linear regression, which is in general an NP-hard optimization problem. Specifically, we show how to cast $ℓ_{0}$ -norm regularization as a quadratic unconstrained binary optimization (QUBO) problem, suitable for implementation on annealing platforms. As a case study, we apply this QUBO formulation to energy flow polynomials in high-energy collider physics, finding that degeneracy engineering substantially improves the annealing performance. Our results motivate the application of degeneracy engineering to a variety of regularized optimization problems.
↳ quant-phhep-exhep-phPRD(2022)·4 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.