Thu·Apr 14, 2022Thursday·April 14, 2022

1. 01*

   A general study of decaying scalar dark matter: existing limits and projected radio signals at the SKA

   Koushik Dutta🇮🇳 · Avirup Ghosh🇮🇳 · Arpan Kar🇰🇷 · Biswarup Mukhopadhyaya🇮🇳

   We consider a decaying scalar dark matter (DM) with mass $m_{\chi }$ in the range 10 GeV - 10 TeV and vary the branching ratios of all possible two-body SM final states (excluding and including $\nu \bar{\nu }$) in the range $0\%-100\%$ to derive constraints on the total decay width $\Gamma$ using the data collected by several astrophysical and cosmological observations. We find that, $\Gamma \lesssim 10^{-26}-10^{-27}{\mathrm{s}}^{-1}$ (excluding $\nu \bar{\nu }$) and $\Gamma \lesssim 10^{-24}-10^{-26}{\mathrm{s}}^{-1}$ (including $\nu \bar{\nu }$) are allowed, depending on the values of $m_{\chi }$, which are most robust upper limits on $\Gamma$ for a generic decaying scalar DM. We then investigate the prospect of the upcoming Square Kilometre Array (SKA) radio telescope in detecting the DM decay induced radio signals originating inside the dwarf spheroidal (dSph) galaxies. We have classified the DM parameter space, allowed by the existing observations, independently of the branching ratio of each individual two-body SM final state, based on the detectability at the SKA. Excluding the $\nu \bar{\nu }$ decay mode, we find that, throughout the DM mass range considered, $\Gamma \gtrsim 10^{-30}{\mathrm{s}}^{-1}-10^{-29}{\mathrm{s}}^{-1}$ is detectable for all possible branching ratio combinations at the SKA (assuming 100 hours of observation time), with conservative choices for the relevant astrophysical parameters. On the other hand, when arbitrary branching ratios are allowed also for the $\nu \bar{\nu }$ decay mode, DM decays can be probed independently of the branching ratio of each SM final state for $\Gamma \gtrsim 2\times 10^{-29}{\mathrm{s}}^{-1}$, provided DM masses are greater than a few hundreds of GeV.

   hep-phastro-ph.HEJCAP(2022)·17 citations
2. 02*

   Dark matter in the NMSSM with small $\lambda$ and $\kappa$

   M. M. Almarashi🇸🇦 · F. Alhazmi🇸🇦 · R. Abdulhafidh🇸🇦 · S. Abdul Basir🇸🇦

   The NMSSM provides an excellent dark matter candidate, usually, the lightest neutralino (${\tilde{\chi }}_1^0$) being the lightest supersymmetric particle (LSP), in the universe. It is a mixture of the bino, the neutral wino, the neutral higgsinos, and the singlino. In this work, we investigate the features of the lightest neutralino by concentrating on a specific region of the NMSSM parameter space with small values of both $\lambda$ and $\kappa$, taking into account theoretical and experimental constraints, including relic density, direct and indirect detection constraints. We have found that the LSP dark matter is a singlino-dominated neutralino for most of the sample points of the chosen scenario. Thus, contrary to expectations, the NMSSM is not comparable to the MSSM in terms of dark matter properties as $\lambda$ and $\kappa$ are very small. The LSP can also be either higgsino-dominated or bino-dominated in some parameter space. The most important parameters affecting the mass and properties of the LSP are $\kappa$, $\lambda /\kappa$, and ${\mu }_{\mathrm{eff}}$. Further, we notice that ${\sigma }_p^{SI}\approx 1.02$ ${\sigma }_n^{SI}$ and ${\sigma }_p^{SD}\approx 0.76$ ${\sigma }_n^{SD}$ for all the surviving sample points.

   hep-phResults Phys.(2023)·6 citations
3. 03*

   Thermodynamics of PNJL at zero temperature in a strong magnetic field

   Yuan Wang🇨🇳 · Xin-Jian Wen🇨🇳

   In this paper, the deconfinement and chiral restoration transitions in strong magnetic field is realized at zero temperature in the Polyakov Nambu$-$Jona-Lasinio model. We provide the thermodynamic treatment to mimic the deconfinement phase transition at zero temperature together with the entangled scalar and vector interactions coupled with the Polyakov loop. The magnetic catalysis is found by a rising behavior of the critical chemical potential for the first-order deconfinement phase transition. While the magnetic catalysis on the chiral restoration could convert to inverse magnetic catalysis under the running coupling interaction ansatz. Furthermore, the stronger magnetic field makes the possible quarkyonic phase window to be enlarged under the running coupling interaction.

   hep-phPRD(2022)·11 citations
4. 04*

   Chirality dependence of thermoelectric response in a thermal QCD medium

   Debarshi Dey🇮🇳 · Binoy Krishna Patra🇮🇳

   The lifting of the degeneracy between L- and R-modes of massless flavors in a weakly magnetized thermal QCD medium leads to a novel phenomenon of chirality dependence of the thermoelectric tensor, whose diagonal and non-diagonal elements are the Seebeck and Hall-type Nernst coefficient, respectively. Both coefficients in L-mode have been found to be greater than their counterparts in R-mode, however the disparity is more pronounced in the Nernst coefficient. Another noteworthy observation is the impact of the dimensionality of temperature (T) profile on the Seebeck coefficient, wherein we find that the coefficient magnitude is significantly enhanced (one order of magnitude) in the 2-D setup, compared to a 1-D T profile. Further, the chiral dependent quasifermion masses constrain the range of magnetic field (B) and T in a manner so as to enforce the weak magnetic field (eB << T^2 ) condition.

   hep-ph2 citations
5. 05*

   Deuteron electromagnetic form factors and tensor polarization observables in the framework of the hard-wall AdS/QCD model

   Narmin Huseynova🇦🇿 · Shahin Mamedov🇦🇿 · Jannat Samadov🇦🇿

   We study the electromagnetic form factors and tensor polarization observables of the deuteron in the framework of the hard-wall AdS/QCD model. We find a profile function for the bulk twist $\tau =6$ vector field, which describes the deuteron on the boundary and fix the infrared boundary cut-off of AdS space in accordance with the ground state mass of the deuteron. We obtain the deuteron charge monopole, quadrupole, and magnetic dipole form factors and tensor polarization observables from the bulk Lagrangians for the deuteron and photon field interactions. We plot the momentum transfer dependence of the form factors and tensor polarization observables and compare our numerical results with those in the soft-wall model and experimental data.

   hep-phnucl-thCPC(2023)·7 citations
6. 06*

   Some recent developments in nonleptonic $B$ decays

   Tobias Huber (Siegen U)🇩🇪

   I report on three recent topics from the field of two-body nonleptonic decays of $B_{(s)}$ mesons. The computation of two-loop NNLO corrections to the leading penguin amplitudes in QCD factorisation, puzzles that have emerged in colour-allowed tree-level decays to heavy-light final states, and a combination of QCD factorisation with $SU(3)$ flavour symmetry to estimate the size of weak-annihilation amplitudes.

   hep-phPoS(2023)·2 citations
7. 07*

   The $B_c$ decay rate in the Standard Model

   Jason Aebischer🇨🇭 · Benjamín Grinstein🇺🇸

   The Standard Model decay rate of the $B_c$ meson is discussed together with a novel approach based on the usage of experimental data in combination with an operator product expansion. In the new method differences of $B,D$ and $B_c$ meson decay rates are considered, for which the free-quark contributions drop out, leading to a reduction of the theory prediction.

   hep-ph1 citation
8. 08*

   The lepton flavor violating decays of vector mesons in the MRSSM

   Ke-Sheng Sun🇨🇳 · Wen-Hui Zhang🇨🇳 · Jian-Bin Chen🇨🇳 · Hai-Bin Zhang🇨🇳

   Recently several new bounds of the lepton flavor violating decays of the neutral vector mesons $J/\psi$ and ${\rm Y}(nS)$ are reported from the experiments. In the work, we analyze these processes in the scenario of the minimal R-symmetric supersymmetric standard model by means of the effective Lagrangian method. The predicted branching ratios are affected by the mass insertion parameters ${\delta }^{ij}$ and the contributions from different parts are comparable. Taking account of the constraints on the mass insertion parameters from the experiments, the branching ratios for the most promising processes ${\rm Y}(nS)\to l\tau$ are predicted to be ten orders of magnitude smaller than the present experimental bounds.

   hep-phCPC(2023)·8 citations
9. 09*

   Next-to-leading order QCD calculation of $B_c$ to charmonium tensor form factors

   Wei Tao🇨🇳 · Zhen-Jun Xiao🇨🇳 · Ruilin Zhu🇨🇳

   We present a next-to-leading order (NLO) QCD corrections to $B_c\to {\eta }_c$ and $B_c\to J/\psi$ tensor form factors within nonrelativistic QCD (NRQCD) framework. The full analytical results for $B_c$ to S-wave charmonium tensor form factors are obtained. We also studied the asymptotic behaviours of tensor form factors in hierarchy heavy quark limit, i.e. $m_b\to \infty ,m_c\to \infty ,\mathrm{and}{m}_c/m_b\to 0$. A compact expression for tensor form factors are given analytically in the hierarchy heavy quark limit. The relation among different form factors is also analyzed especially at large momentum recoil point. The numerical results for the $B_c$ to charmonium tensor form factors in all the physical region are given in the end.

   hep-phPRD(2022)·14 citations
10. 10*

    Flavour anomalies and dark matter assisted unification in $SO(10)$ GUT

    Purushottam Sahu🇮🇳 · Aishwarya Bhatta🇮🇳 · Rukmani Mohanta🇮🇳 · Shivaramakrishna Singirala🇮🇳 · Sudhanwa Patra🇮🇳

    With the recent experimental hint of new physics from flavor physics anomalies, combined with the evidence from neutrino mass and dark matter, we consider a minimal extension of SM with a scalar leptoquark and a fermion triplet. The scalar leptoquark with couplings to leptons and quarks can explain lepton flavor non-universality observables $R_K$, $R_{K^{(\ast )}}$, $R_{D^{(\ast )}}$ and $R_{J/\psi }$. Neutral component of fermion triplet provides current abundance of dark matter in the Universe. The interesting feature of the proposal is that the minimal addition of these phenomenologically rich particles (scalar leptoquark and fermion triplet) assist in realizing the unification of the gauge couplings associated with the strong and electroweak forces of standard model when embedded in the non-supersymmetric $SO(10)$ grand unified theory. We discuss on unification mass scale and the corresponding proton decay constraints while taking into account the GUT threshold corrections.

    hep-phJHEP(2022)·4 citations
11. 11*

    Multilepton Signatures from Dark Matter at the LHC

    Alexander Belyaev🇬🇧 · Ulla Blumenschein🇬🇧 · Arran Freegard🇬🇧 · Stefano Moretti🇬🇧 · Dipan Sengupta🇺🇸

    Leptonic signatures of Dark Matter (DM) are one of the cleanest ways to discover such a secluded form of matter at high energy colliders. We explore the full parameter space relevant to multi-lepton (2- and 3-lepton) signatures at the Large Hadron Collider (LHC) from representative minimal consistent models with scalar and fermion DM. In our analysis, we suggest a new parametrisation of the model parameter spaces in terms of the DM mass and mass differences between DM and its multiplet partners. This parametrisation allows us to explore properties of DM models in their whole parameter space. This approach is generic and quite model-independent since the mass differences are related to the couplings of the DM to the Standard Model (SM) sector. We establish the most up-to-date LHC limits on the inert 2-Higgs Doublet Model (i2HDM) and Minimal Fermion DM (MFDM) model parameter spaces, by using the complementary information stemming from 2- and 3-lepton signatures. We provide a map of LHC efficiencies and cross-section limits for such 2- and 3-lepton signatures allowing one to easily make model-independent reinterpretations of LHC results for analogous classes of models. We also present combined constraints from the LHC, DM relic density and direct search experiments indicating the current status of the i2HDM and MFDM model.

    hep-phJHEP(2022)·9 citations
12. 12*

    Radiative Effects in the Scalar Sector of Vector Leptoquark Models

    Rachel Houtz🇬🇧 · Julie Pagès🇨🇭 · Sokratis Trifinopoulos🇮🇹

    Gauge models with massive vector leptoquarks at the TeV scale provide a successful framework for addressing the B-physics anomalies. Among them, the 4321 model has been considered as the low-energy limit of some complete theories of flavor. In this work, we study the renormalization group evolution of this model, laying particular emphasis on the scalar sector. We find that, despite the asymptotic freedom of the gauge couplings, Landau poles can arise at relatively low scale due to the fast running of quartic couplings. Moreover, we discuss the possibility of radiative electroweak symmetry breaking, and characterize the fine-tuning associated with the hierarchy between the electroweak scale and the additional TeV-scale scalars. Finally, the idea of scalar fields unification is explored, motivated by ultraviolet embeddings of the 4321 model.

    hep-phJHEP(2022)·4 citations
13. 13*

    Normal and Reverse Annual Modulations of Elastic WIMP-Nucleus Scattering Signals

    Chung-Lin Shan🇹🇼

    Following our earlier work on the 3-dimensional effective velocity distribution of Galactic WIMPs (not only impinging on our detectors but also) scattering off target nuclei, in this paper, we demonstrate the normal and a "reverse" annual modulations of elastic WIMP-nucleus scattering signals, which could be observed in direct Dark Matter detection experiments. Our simulations show that, once the WIMP mass is as light as only a few tens GeV, the event number and the accumulated recoil energy of WIMP-induced scattering events off both of light and heavy target nuclei would indeed be maximal (minimal) in summer (winter). However, once the WIMP mass is as heavy as a few hundreds GeV, the event number and the accumulated recoil energy of WIMP scattering events off heavy nuclei would inversely be minimal in summer. Understandably, for an intermediate WIMP mass, the event number and the accumulated recoil energy of scattering events off some middle-mass nuclei would show an approximately uniform time dependence.

    hep-phastro-ph.HEhep-ex0 citations
14. 14*

    Anomalous U(1) Gauge Bosons and String Physics at the Forward Physics Facility

    Luis A. Anchordoqui🇺🇸 · Ignatios Antoniadis🇫🇷 · Karim Benakli🇫🇷 · Dieter Lust🇩🇪

    We show that experiments at the Forward Physics Facility, planned to operate near the ATLAS interaction point during the LHC high-luminosity era, will be able to probe predictions of Little String Theory by searching for anomalous U(1) gauge bosons living in the bulk. The interaction of the abelian broken gauge symmetry with the Standard Model is generated at the one-loop level through kinetic mixing with the photon. Gauge invariant generation of mass for the U(1) gauge boson proceeds via the Higgs mechanism in spontaneous symmetry breaking, or else through anomaly-cancellation appealing to Stueckelberg-mass terms. We demonstrate that FASER2 will be able to probe string scales over roughly two orders of magnitude: 10^5 < M_s/TeV < 10^7.

    hep-phhep-thPLB(2022)·5 citations
15. 15*

    Baryon number violation from confining New Physics

    Mathew Thomas Arun🇮🇳

    The detection of neutron-antineutron oscillation will be a discovery of fundamental importance in particle physics and cosmology. In models discussed widely in literature, the process is generated through heavy New Physics with weak, perturbative, coupling at the scale of the experiment. Acknowledging the fact that Nature has been quite evasive regarding the strength and scale of New Physics, we discuss a new mechanism, generated by confining New Physics, at $\sim 2$ GeV, resulting in low-energy baryon number violating effects. The mechanism predicts baryon number violating processes like neutron disappearance, neutron-neutron annihilation and neutron-anti neutron oscillation generated through the condensation of the linear moose.

    hep-phastro-ph.HEPRD(2023)·5 citations
16. 16*

    Implications of the new CDF-II $W$-boson mass on two-Higgs-doublet models

    Yang Hwan Ahn🇰🇷 · Sin Kyu Kang🇰🇷 · Raymundo Ramos🇰🇷

    We present the implications of the recent measurement of $W$ boson at CDF II on the two-Higgs-doublet model (2HDM). In the analysis, we impose theoretical bounds such as vacuum stability and perturbative unitarity, and several experimental constraints. In addition, we take into account the measurement of ${\sin }^2{\theta }_W(m_Z{)}_{\overline{\mathrm{MS}}}$ on top of the CDF $W$-boson mass to investigate how the $S$ and $T$ parameters are determined. We explore two possible scenarios depending on whether the Higgs boson observed at the LHC is the lighter or heavier of $CP$-even neutral Higgs bosons for 2HDM type I and II. Using the results, we show how the parameter space is constrained, and compare it with the one based on the PDG average of $m_W$. Furthermore, we explore phenomenological consequences of electroweak precision observables that can be affected by $m_W$ within the predictions of the 2HDM, and the reduction in parameter space expected from future measurements at the Future Circular Lepton Collider.

    hep-phPRD(2022)·91 citations
17. 17*

    Quantum clustering and jet reconstruction at the LHC

    Jorge J. Martínez de Lejarza🇪🇸 · Leandro Cieri🇪🇸 · Germán Rodrigo🇪🇸

    Clustering is one of the most frequent problems in many domains, in particular, in particle physics where jet reconstruction is central in experimental analyses. Jet clustering at the CERN's Large Hadron Collider (LHC) is computationally expensive and the difficulty of this task will increase with the upcoming High-Luminosity LHC (HL-LHC). In this paper, we study the case in which quantum computing algorithms might improve jet clustering by considering two novel quantum algorithms which may speed up the classical jet clustering algorithms. The first one is a quantum subroutine to compute a Minkowski-based distance between two data points, whereas the second one consists of a quantum circuit to track the maximum into a list of unsorted data. The latter algorithm could be of value beyond particle physics, for instance in statistics. When one or both of these algorithms are implemented into the classical versions of well-known clustering algorithms (K-means, Affinity Propagation and $k_T$-jet) we obtain efficiencies comparable to those of their classical counterparts. Even more, exponential speed-up could be achieved, in the first two algorithms, in data dimensionality and data length when the distance algorithm or the maximum searching algorithm are applied.

    hep-phhep-exquant-phPRD(2022)·40 citations
18. 18*

    High-energy emissions of light mesons plus heavy flavor at the LHC and the Forward Physics Facility

    Francesco Giovanni Celiberto🇮🇹

    The study of the dynamics of strong interactions in the high-energy regime is a core line of frontier researches at the LHC as well as at new-generation colliding facilities. Here, the enhancement of energy logarithms due to diffractive semi-hard final states spoils the convergence of the perturbative series in the QCD running coupling, thus calling for an improvement of the pure collinear factorization that accounts for an all-order resummation of these large logarithmic contributions. Motivated by the recent discovery that inclusive emissions of heavy-flavored particles allow for clear signals of a stabilization of high-energy resummed differential distributions under higher-order corrections and scale variations, we provide novel predictions of rapidity and azimuthal-angle observables for the inclusive hadroproduction of a light meson ($\eta$ or ${\pi }^{\pm }$) in association with a heavy-flavored hadron (${\Lambda }_c$ or $b$-flavored hadron). We calculate our observables in a hybrid high-energy and collinear factorization framework, where next-to-leading BFKL-resummed partonic cross sections are convoluted with collinear parton distributions and fragmentation functions. We consider kinematic ranges typically covered by acceptances of LHC detectors, and new ones coming from the combined tag of an ultra-forward particle at the future Forward Physics Facility (FPF) and of a central one at ATLAS via a tight timing-coincidence setup. By performing a detailed study on uncertainties associated to collinear inputs via a replica-driven analysis, as well as on ones intrinsically coming from the high-energy resummation, we highlight the challenges and the steps required to gauge the feasibility of precision studies of our processes.

    hep-phhep-exhep-thPRD(2022)·65 citations
19. 19*

    A joint explanation of W-mass and muon g-2 in 2HDM

    Xiao-Fang Han🇨🇳 · Fei Wang🇨🇳 · Lei Wang🇨🇳 · Jin Min Yang🇨🇳 · Yang Zhang🇨🇳

    Since both $W$-mass and muon $g-2$ can be affected by the mass splittings among extra Higgs bosons $(H,A,H^{\pm })$ in a 2HDM, we take a model with $\mu$-$\tau$ LFV interactions to examine the two anomalies reported respectively by CDF II and FNAL. We obtain the following observations: (i) Combined with theoretical constraints, the CDF $W$-mass measurement disfavors $H$ or $A$ to degenerate in mass with $H^{\pm }$, but allows $H$ and $A$ to degenerate. The mass splitting between $H^{\pm }$ and $H/A$ is required to be larger than 10 GeV. The $m_{H^{\pm }}$ and $m_A$ are favored to be smaller than 650 GeV for $m_H<120$ GeV, and allowed to have more large values with increasing of $m_H$. (ii) After imposing other relevant experimental constraints, there are parameter spaces that simultaneously satisfy (at $2\sigma$ level) the CDF $W$-mass, the FNAL muon $g-2$ and the data of lepton universality in $\tau$ decays, but the mass splittings among extra Higgs bosons are strictly constrained.

    hep-phCPC(2022)·91 citations
20. 20*

    The $W\ell \nu$-vertex corrections to W-boson mass in the R-parity violating MSSM

    Min-Di Zheng🇨🇳 · Feng-Zhi Chen🇨🇳 · Hong-Hao Zhang🇨🇳

    Inspired by the astonishing $7\sigma$ discrepancy between the recent CDF-II measurement and the standard model prediction on the mass of $W$-boson, we investigate the ${\lambda }^{\prime }$-corrections to the vertex of $\mu \to {\nu }_{\mu }e\overline{{\nu }_e}$ decay in the context of the $R$-parity violating minimal supersymmetric standard model. These corrections can raise the $W$-boson mass independently. Combined with recent $Z$-pole and kaon decay measurements, $m_W\lesssim 80.37$ GeV can be reached. We find that these vertex corrections cannot explain the CDF result entirely at the $2\sigma$ and even $3\sigma$ levels. However, these corrections together with the oblique contributions can be accordant with the CDF-II result and relevant bounds at the $3\sigma$ level.

    hep-phhep-exAAPPS Bull.(2023)·57 citations
21. 21*

    Using quasar and gamma-ray burst measurements to constrain cosmological dark energy models

    Narayan Khadka🇺🇸

    Observational evidence for the accelerated expansion of the universe requires dark energy for its explanation if general relativity is an accurate model of gravity. However, dark energy is a mysterious quantity and we do not know much about its nature so understanding dark energy is an exciting scientific challenge. Cosmological dark energy models are fairly well tested in the low and high redshift parts of the universe. The highest of the low redshift, $z\sim 2.3$, region is probed by baryon acoustic oscillation (BAO) measurements and the only high redshift probe is the cosmic microwave background anisotropy which probes the $z\sim 1100$ part of redshift space. In the intermediate redshift range $2.3<z<1100$ there are only a handful of observational probes and cosmological models are poorly tested in this region. In this thesis we constrain three pairs of general relativistic cosmological dark energy models using observational data which reach beyond the current BAO limit. We use quasar X-ray and UV flux measurements, the current version of these data span $0.009\le z\le 7.5413$. We have discovered that most of these data cannot be standardized using the proposed method. However, the lower redshift part, $z\lesssim 1.5-1.7$, of these data are standardizable and can be used to derive lower-$z$ cosmological constraints. Another data set we use are gamma-ray burst measurements which span $0.3399\le z\le 8.2$. Cosmological constraints derived from these data are significantly weaker than, but consistent with, those obtained from better-established cosmological probes. We also study and standardize 78 reverberation-measured Mg II time-lag quasars in the redshift range $0.0033\le z\le 1.89$ by using their radius-luminosity relation. We also study 118 reverberation-measured H$\beta$ time-lag quasars which span $0.0023\le z\le 0.89$.

    ↳ astro-ph.COgr-qchep-phhep-th0 citations
22. 22*

    Non-equilibrium dynamics of fluctuations in an ultra-cold atomic mixture

    Apoorva Hegde🇩🇪 · Robert Ott🇩🇪 · Andy Xia🇩🇪 · Valentin Kasper🇪🇸 · Jürgen Berges🇩🇪 · Fred Jendrzejewski🇩🇪

    We investigate an ultra-cold mixture of Bose gases interacting via spin-changing collisions by studying the dynamics of spin fluctuations. The experimental implementation employs ${}^{23}$Na and ${}^7$Li atoms, which are prepared out of equilibrium across a wide range of initial conditions. We identify three regimes in the dynamics of the system for different initial states: a long-lived metastable regime, an instability range with strong growth of fluctuations, and a fast relaxing regime approaching thermal equilibrium. Theoretical modelling of the data allows us to reconstruct effective potentials which characterize the different dynamical regimes of the system.

    ↳ cond-mat.quant-gashep-phquant-phPRA(2023)·3 citations
23. 23*

    Snowmass White Paper: the Double Copy and its Applications

    Tim Adamo🇬🇧 · John Joseph M. Carrasco🇺🇸 · Mariana Carrillo-González🇬🇧 · Marco Chiodaroli🇸🇪 · Henriette Elvang🇺🇸 · Henrik Johansson🇸🇪 · Donal O'Connell🇬🇧 · Radu Roiban🇺🇸 · Oliver Schlotterer🇺🇸

    The double copy is, in essence, a map between scattering amplitudes in a broad variety of familiar field and string theories. In addition to the mathematically rich intrinsic structure, it underlies a multitude of active research directions and has a range of interesting applications in quantum, classical and effective field theories, including broad topics such as string theory, particle physics, astrophysics, and cosmology. This Snowmass white paper provides a brief introduction to the double copy, its applications, current research and future challenges.

    ↳ hep-thgr-qchep-phmath-ph+1180 citations
24. 24*

    Universal gravothermal evolution of isolated self-interacting dark matter halos for velocity-dependent cross sections

    Nadav Joseph Outmezguine🇺🇸 · Kimberly K. Boddy🇺🇸 · Sophia Gad-Nasr🇺🇸 · Manoj Kaplinghat🇺🇸 · Laura Sagunski🇩🇪

    We study the evolution of isolated self-interacting dark matter (SIDM) halos using spherically-symmetric gravothermal equations allowing for the scattering cross section to be velocity dependent. We focus our attention on the large class of models where the core is in the long mean free path regime for a substantial time. We find that the temporal evolution exhibits an approximate universality that allows velocity-dependent models to be mapped onto velocity-independent models in a well-defined way using the scattering timescale computed when the halo achieves its minimum central density. We show how this timescale depends on the halo parameters and an average cross section computed at the central velocity dispersion when the central density is minimum. The predicted collapse time is fully defined by the scattering timescale, with negligible variation due to the velocity dependence of the cross section. We derive new self-similar solutions that provide an analytic understanding of the numerical results.

    ↳ astro-ph.GAhep-phMNRAS(2023)·86 citations
25. 25*

    Tuning the Topological $\theta$-Angle in Cold-Atom Quantum Simulators of Gauge Theories

    Jad C. Halimeh🇩🇪 · Ian P. McCulloch🇦🇺 · Bing Yang🇨🇳 · Philipp Hauke🇮🇹

    The topological $\theta$-angle in gauge theories engenders a series of fundamental phenomena, including violations of charge-parity (CP) symmetry, dynamical topological transitions, and confinement--deconfinement transitions. At the same time, it poses major challenges for theoretical studies, as it implies a sign problem in numerical simulations. Analog quantum simulators open the promising prospect of treating quantum many-body systems with such topological terms, but, contrary to their digital counterparts, they have not yet demonstrated the capacity to control the $\theta$-angle. Here, we demonstrate how a tunable topological $\theta$-term can be added to a prototype theory with $\mathrm{U}(1)$ gauge symmetry, a discretized version of quantum electrodynamics in one spatial dimension. As we show, the model can be realized experimentally in a single-species Bose--Hubbard model in an optical superlattice with three different spatial periods, thus requiring only standard experimental resources. Through numerical calculations obtained from the time-dependent density matrix renormalization group method and exact diagonalization, we benchmark the model system, and illustrate how salient effects due to the $\theta$-term can be observed. These include charge confinement, the weakening of quantum many-body scarring, as well as the disappearance of Coleman's phase transition due to explicit breaking of CP symmetry. This work opens the door towards studying the rich physics of topological gauge-theory terms in large-scale cold-atom quantum simulators.

    ↳ cond-mat.quant-gascond-mat.str-elhep-lathep-ph+1PRX Quantum(2022)·70 citations
26. 26*

    Moiré Gravity and Cosmology

    Alireza Parhizkar🇺🇸 · Victor Galitski🇺🇸

    The vacuum catastrophe is a fundamental puzzle, where the observed scales of the cosmological constant are many orders of magnitude smaller than the natural scales expected in the theory. This work proposes a new "bi-world" construction that may offer an insight into the cosmological constant problem. The model generally includes a $(3+1)$-dimensional manifold with two different geometries and matter fields residing on them. In contrast to bimetric or massive theories of gravity, classically, and in the vacuum limit, the model reduces to two massless gravity theories, thereby living ghost-free. The diffeomorphism invariance and causality highly constrain the two metrics to be conformally related, ${\eta }_{\mu \nu }={\varphi }^2{g}_{\mu \nu }$. This reduces the theory to a standard single-world description, but introduces a new inherently geometrical "moiré field," $\varphi$. Interestingly, the moiré field has the character of both a dilaton and Higgs field familiar in the conventional theory. Integrating out the moiré field naturally gives rise to the Starobinsky action and inflationary dynamics. In the framework of the Friedmann-Lemaitre-Robertson-Walker solution, we reduce an effective action for the moiré field to that of a particle moving in a Mexican hat potential. The equations of motion are then solved numerically and the moiré field is shown to approach a Mexican-hat minimum in an oscillatory fashion, which is accompanied by the decay of the Hubble parameter. Under additional reasonable assumptions, the vacuum energy asymptotically approaches zero in the end of inflationary evolution. The physics presented here shares similarities with the moiré phenomena in condensed matter and elsewhere, where two similar structures superimposed upon give rise to a superstructure with low emergent energy scales compared to the native theories.

    ↳ hep-thcond-mat.othergr-qchep-ph4 citations
27. 27*

    BeAGLE: Benchmark $e$A Generator for LEptoproduction in high energy lepton-nucleus collisions

    Wan Chang🇨🇳 · Elke-Caroline Aschenauer🇺🇸 · Mark D. Baker🇺🇸 · Alexander Jentsch🇺🇸 · Jeong-Hun Lee🇺🇸 · Zhoudunming Tu🇺🇸 · Zhongbao Yin🇨🇳 · Liang Zheng🇨🇳

    The upcoming Electron-Ion Collider (EIC) will address several outstanding puzzles in modern nuclear physics. Topics such as the partonic structure of nucleons and nuclei, the origin of their mass and spin, among others, can be understood via the study of high energy electron-proton ($ep$) and electron-nucleus ($e$A) collisions. Achieving the scientific goals of the EIC will require a novel electron-hadron collider and detectors capable to perform high-precision measurements, but also dedicated tools to model and interpret the data. To aid in the latter, we present a general-purpose $e$A Monte Carlo (MC) generator - BeAGLE. In this paper, we provide a general description of the models integrated into BeAGLE, applications of BeAGLE in $e$A physics, implications for detector requirements at the EIC, and the tuning of the parameters in BeAGLE based on available experimental data. Specifically, we focus on a selection of model and data comparisons in particle production in both $ep$ and $e$A collisions, where baseline particle distributions provide essential information to characterize the event. In addition, we investigate the collision geometry determination in $e$A collisions, which could be used as an experimental tool for varying the nuclear density.

    ↳ physics.comp-phhep-phnucl-exnucl-th+2PRD(2022)·30 citations

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