Fri·Jul 21, 2023Friday·July 21, 2023

1. 01*

   Luminosity for laser-electron colliders

   B. Manuel Hegelich🇺🇸 · Calin I. Hojbota🇰🇷 · Lance A. Labun🇺🇸 · Ou Z. Labun🇺🇸 · Dung D. Phan🇺🇸

   High intensity laser facilities are expanding their scope from laser and particle-acceleration test beds to user facilities and nuclear physics experiments. A basic goal is to confirm long-standing predictions of strong-field quantum electrodynamics, but with the advent of high-repetition rate laser experiments producing GeV-scale electrons and photons, novel searches for new high-energy particle physics also become possible. The common figure of merit for these facilities is the invariant $\chi \simeq 2{\gamma }_e|{\vec{E}}_{\mathrm{laser}}|/E_c$ describing the electric field strength in the electron rest frame relative to the ``critical'' field strength of quantum electrodynamics where the vacuum decays into electron-positron pairs. However, simply achieving large $\chi$ is insufficient; discovery or validation requires statistics to distinguish physics from fluctuations. The number of events delivered by the facility is therefore equally important. In high-energy physics, luminosity quantifies the rate at which colliders provide events and data. We adapt the definition of luminosity to high-intensity laser-electron collisions to quantify and thus optimize the rate at which laser facilities can deliver strong-field QED and potentially new physics events. Modeling the pulsed laser field and electron bunch, we find that luminosity is maximized for laser focal spot size equal or slightly larger than the diameter of the dense core of the electron bunch. Several examples show that luminosity can be maximized for parameters different from those maximizing the peak value of $\chi$ in the collision. The definition of luminosity for electron-laser collisions is straightforwardly extended to photon-laser collisions and lepton beam-beam collisions.

   hep-phphysics.acc-phphysics.plasm-ph0 citations
2. 02*

   Analytic Solution for the Revised Helicity Evolution at Small $x$ and Large $N_c$: New Resummed Gluon-Gluon Polarized Anomalous Dimension and Intercept

   Jeremy Borden🇺🇸

   We construct an exact analytic solution of the revised small-$x$ helicity evolution equations derived recently. The equations we solve are obtained in the large-$N_c$ limit (with $N_c$ the number of quark colors) and are double-logarithmic (summing powers of ${\alpha }_s{\ln }^2(1/x)$ with ${\alpha }_s$ the strong coupling constant and $x$ the Bjorken $x$ variable). Our solution provides small-$x$, large-$N_c$ expressions for the flavor-singlet quark and gluon helicity parton distribution functions (PDFs) and for the $g_1$ structure function, with their leading small-$x$ asymptotics given by \begin{align} \Delta \Sigma (x, Q^2) \sim \Delta G (x, Q^2) \sim g_1 (x, Q^2) \sim \left( \frac{1}{x} \right)^{\alpha_h} , \notag \end{align} where the exact analytic expression we obtain for the intercept ${\alpha }_h$ can be approximated by ${\alpha }_h=3.66074\sqrt{\frac{{\alpha }_s{N}_c}{2\pi }}$. Our solution also yields an all-order (in ${\alpha }_s$) resummed small-$x$ anomalous dimension $\Delta {\gamma }_{GG}(\omega )$ which agrees with all the existing fixed-order calculations (to three loops). Notably, our anomalous dimension is different from that obtained in the infrared evolution equation framework developed earlier by Bartels, Ermolaev, and Ryskin (BER), with the disagreement starting at four loops. Despite the previously reported agreement at two decimal points based on the numerical solution of the same equations, the intercept of our large-$N_c$ helicity evolution and that of BER disagree beyond that precision, with the BER intercept at large $N_c$ given by a different analytic expression from ours with the numerical value of ${\alpha }_h^{BER}=3.66394\sqrt{\frac{{\alpha }_s{N}_c}{2\pi }}$. We speculate on the origin of this disagreement.

   hep-phnucl-th2 citations
3. 03*

   Violation of C/CP Symmetry Induced by a Scalar Field Emerging from a Two-Brane Universe: A Gateway to Baryogenesis

   Michael Sarrazin🇫🇷 · Coraline Stasser🇧🇪

   A model of baryogenesis is introduced where our usual visible Universe is a 3-brane coevolving with a hidden 3-brane in a multidimensional bulk. The visible matter and antimatter sectors are naturally coupled with the hidden matter and antimatter sectors, breaking the C/CP invariance and leading to baryogenesis occurring after the quark-gluon era. The issue of leptogenesis is also discussed. The symmetry breaking spontaneously occurs due to the presence of an extra scalar field supported by the $U(1)\otimes U(1)$ gauge group, which extends the conventional electromagnetic gauge field in the two-brane universe. Observational consequences are discussed.

   hep-phastro-ph.COhep-thPRD(2024)·2 citations
4. 04*

   Spectroscopy of Heavy-Light Mesons ($c\bar{s}$, $c\bar{q}$, $b\bar{s}$, $b\bar{q}$) for the linear plus modified Yukawa potential using Nikiforov-Uvarov Method

   Kaushal R Purohit🇮🇳 · Ajay Kumar Rai🇮🇳 · Rajendrasinh H Parmar🇮🇳

   An approximate bound state solution of the Klein-Gordon equation is derive analytically for the 3-dimensional space with a combination framework of linear plus modified Yukawa Potential (LIMYP) using the Nikiforov-Uvarov (N-U) method for obtaining the energy eigenvalues and corresponding wave function. A detailed study of mass spectra of all combination sets of heavy-light flavor mesons vis-a-vis $(Ks/Kq;K=C,B)$ is investigated by treating both heavy-light flavor mesons non-relativistic with an effective quark-antiquark interaction potential for different quantum states. Along with that, an elucidated graphical representation is scrutinized with the calculated mass spectra obtained from the energy eigenvalue against the corresponding variables for all the combination sets of heavy-light flavors mesons. Therefore, the current framework potential provides excellent reconciliation with the experimental data of states known to date and minuscule \% difference in lower quantum states, which increases with higher quantum states that can be correlated with the higher screening factor coming into the account.

   hep-phIndian J.Phys.(2024)·4 citations
5. 05*

   A model for pion collinear parton distribution function and form factor

   Simone Venturini🇮🇹 · Barbara Pasquini🇮🇹 · Simone Rodini🇫🇷

   We developed a model for the pion light-front wave function (LFWF) that incorporates valence, sea and gluon degrees of freedom. Using the LFWF overlap representation, we derived parametrizations for the pion parton distribution functions and the electromagnetic form factor. These parametrizations depend on two distinct sets of parameters, enabling separate fits of the longitudinal- and transverse-momentum dependencies of the LFWF. The pion PDFs are extracted from available Drell-Yan and photon-production data using the xFitter framework and are found well compatible with existing extractions. Furthermore, the fit of the electromagnetic form factor of the pion to all the available experimental data works quite successfully.

   hep-ph1 citation
6. 06*

   Probing the weak mixing angle at high energy

   Clara Lavinia Del Pio🇮🇹 · Simone Amoroso🇩🇪 · Mauro Chiesa🇮🇹 · Ekaterina Lipka🇩🇪 · Fulvio Piccinini🇮🇹 · Federico Vazzoler🇩🇪 · Alessandro Vicini🇮🇹

   The weak mixing angle is a probe of the vector-axial coupling structure of electroweak interactions. It has been measured precisely at the $Z$-pole by experiments at the LEP and SLD colliders, but its energy dependence above $M_Z$ remains unconstrained. In this contribution we propose to exploit measurements of Neutral-Current Drell Yan at large invariant dilepton masses at the Large Hadron Collider, to determine the scale dependence of the weak mixing angle in the $\overline{MS}$ renormalisation scheme, ${\sin }^2{\theta }_w^{\overline{MS}}(\mu )$. Such a measurement can be used to test the Standard Model predictions for the $\overline{MS}$ running at TeV scales, and to set model-independent constraints on new states with electroweak quantum numbers. To this end, we present an implementation of ${\sin }^2{\theta }_w^{\overline{MS}}(\mu )$ in the POWHEG-BOX Monte Carlo event generator, which we use to explore the potential of future analyses with the LHC Run~3 and High-Luminosity datasets. In particular, the impact of the higher order corrections and of the uncertainties due to the knowledge of parton distribution functions are studied.

   hep-ph0 citations
7. 07*

   Mass and decay of the $s\bar{s}$ member of the $1^3{F}_4$ meson nonet

   Xue-Chao Feng🇨🇳 · Ke-Wei Wei🇨🇳

   The mass and decay of the $s\bar{s}$ member of the $1^3{F}_4$ meson nonet are investigated in the framework of the Regge phenomenology and the ${}^3{P}_0$ model. We propose, based on the results, that the assignment of the $s\bar{s}$ member of the $1^3{F}_4$ meson nonet will require additional testing in the future. Our results also provide information for future studies of the $1^3{F}_4$ meson nonet.

   hep-phActa Phys.Polon.B(2023)·1 citation
8. 08*

   Fluid dynamics from the Boltzmann equation using a maximum entropy distribution

   Chandrodoy Chattopadhyay🇺🇸 · Ulrich Heinz🇺🇸 · Thomas Schaefer🇺🇸

   Using the recently developed ``Maximum Entropy'' (or ``least biased'') distribution function to truncate the moment hierarchy arising from kinetic theory, we formulate a far-from-equilibrium macroscopic theory that provides the possibility of describing both free-streaming and hydrodynamic regimes of heavy-ion collisions within a single framework. Unlike traditional hydrodynamic theories that include viscous corrections to finite order, the present formulation incorporates contributions to all orders in shear and bulk inverse Reynolds numbers, allowing it to handle large dissipative fluxes. By considering flow profiles relevant for heavy-ion collisions (Bjorken and Gubser flows), we demonstrate that the present approach provides excellent agreement with underlying kinetic theory throughout the fluid's evolution and, especially, in far-off-equilibrium regimes where traditional hydrodynamics breaks down.

   hep-phnucl-thPRC(2023)·14 citations
9. 09*

   Lepton flavor violating dark photon

   Alexey S. Zhevlakov🇷🇺 · Dmitry V. Kirpichnikov🇷🇺 · Valery E. Lyubovitskij🇩🇪

   We study possible impact of dark photons on lepton flavor phenomenology. We derive the constraints on non-diagonal dark photon couplings with leptons by analyzing corresponding contributions to lepton anomalous magnetic moments, rare lepton decays and the prospects of fixed-target experiments aiming for search for light dark matter based on missing energy/momentum techniques.

   hep-phPRD(2024)·13 citations
10. 10*

    Correlating neutrino magnetic moment and scalar triplet dark matter to enlighten XENONnT bounds in a Type-II model

    Shivaramakrishna Singirala🇮🇳 · Dinesh Kumar Singha🇮🇳 · Rukmani Mohanta🇮🇳

    We investigate neutrino magnetic moment, triplet scalar dark matter in a Type-II radiative seesaw scenario. With three vector-like fermion doublets and two scalar triplets, we provide a loop level setup for the electromagnetic vertex of neutrinos. All the scalar multiplet components constitute the total dark matter abundance of the Universe and also their scattering cross section with detector lie below the experimental upper limit. Using the consistent parameter space in dark matter domain, we obtain light neutrino mass in sub-eV scale and also magnetic moment in the desired range. We further derive the constraints on neutrino transition magnetic moments, consistent with XENONnT limit.

    hep-phPRD(2024)·4 citations
11. 11*

    Radiative decays of the heavy-quark-spin molecular partner of $T_{cc}^{+}$

    Zhao-Sai Jia🇨🇳 · Zhen-Hua Zhang🇨🇳 · Gang Li🇨🇳 · Feng-Kun Guo🇨🇳

    With the assumptions that the $T_{cc}^{+}$ discovered at LHCb is a $D^{\ast }D$ hadronic molecule, using a nonrelativistic effective field theory we calculate the radiative partial widths of $T_{cc}^{\ast }\to D^{\ast }D\gamma$ with $T_{cc}^{\ast }$ being a $D^{\ast }{D}^{\ast }$ shallow bound state and the heavy-quark-spin partner of $T_{cc}^{+}$. The $I=0$ $D^{\ast }D$ rescattering effect with the $T_{cc}$ pole is taken into account. The results show that the isoscalar $D^{\ast }D$ rescattering can increase the tree-level decay width of $T_{cc}^{\ast +}\to D^{\ast +}{D}^0\gamma$ by about $50\%$, while decrease that of $T_{cc}^{\ast +}\to D^{\ast 0}{D}^{+}\gamma$ by a similar amount. The two-body partial decay widths of the $T_{cc}^{\ast +}$ into $T_{cc}^{+}\gamma$ and $T_{cc}^{+}{\pi }^0$ are also calculated, and the results are about $6\mathrm{keV}$ and $3\mathrm{keV}$, respectively. Considering that the $D^{\ast }$ needs to be reconstructed from the $D\pi$ or $D\gamma$ final state in an experimental measurement, the four-body partial widths of the $T_{cc}^{\ast +}$ into $DD\gamma \gamma$ and $DD\pi \gamma$ are explicitly calculated, and we find that the interference effect between different intermediate $D^{\ast }D\gamma$ states is small. The total radiative decay width of the $T_{cc}^{\ast }$ is predicted to be about $24\mathrm{keV}$. Adding the hadronic decay widths of $T_{cc}^{\ast }\to D^{\ast }D\pi$, the total width of the $T_{cc}^{\ast }$ is finally predicted to be $(65\pm 2)$ keV.

    hep-phPRD(2023)·9 citations
12. 12*

    Astrophysical Constraints on Decaying Dark Gravitons

    Jamie A.P. Law-Smith🇺🇸 · Georges Obied🇬🇧 · Anirudh Prabhu🇺🇸 · Cumrun Vafa🇺🇸

    In the dark dimension scenario, which predicts an extra dimension of micron scale, dark gravitons (KK modes) are a natural dark matter candidate. In this paper, we study observable features of this model. In particular, their decay to standard matter fields can distort the CMB and impact other astrophysical signals. Using this we place bounds on the parameters of this model. In particular we find that the natural range of parameters in this scenario is consistent with these constraints and leads to the prediction that the mean mass of the dark matter today is close to a few hundred keV and the effective size of the extra dimension is around $1-30\mu \mathrm{m}$.

    hep-phastro-ph.COhep-thJHEP(2024)·36 citations
13. 13*

    Comprehensive Measurement Forecasts of the EeV Neutrino-Nucleon Cross Section with Cosmic Neutrinos at IceCube-Gen2

    Victor B. Valera🇩🇰 · Mauricio Bustamante🇩🇰 · Christian Glaser🇸🇪

    The investigation of neutrino interactions with matter serves as a valuable tool for understanding the fundamental structure of nucleons and potentially uncovering novel physics phenomena. To date, the neutrino-nucleon cross section has been examined across a range of energies spanning from a few hundred MeV to PeV. However, the pursuit of ultra-high-energy (UHE) cosmic neutrinos, surpassing 100 PeV in energy, holds the promise of further advancements. In the next 10-20 years, UHE neutrino telescopes, currently in the planning stage, may ultimately succeed in their detection. This article presents pioneering and comprehensive estimation forecasts for the ultra-high-energy neutrino-nucleon cross section, with a specific focus on the employment of neutrino radio-detection within the IceCube-Gen2 experiment. The study incorporates cutting-edge methodologies in UHE neutrino flux prediction, neutrino propagation within the Earth, radio detection techniques, and the treatment of background data to facilitate accurate cross section measurement projections. Assuming the successful detection of at least a few tens of UHE neutrino-induced events over a 10-year period, IceCube-Gen2 could achieve, for the first time, the measurement of the cross section at center-of-mass energies of approximately $\sqrt{s}\approx 10$--100 TeV. Furthermore, if the number of events exceeds one hundred, the precision of the cross section measurement could be comparable to its corresponding theoretical prediction.

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

    On the sensitivity reach of LQ production with preferential couplings to third generation fermions at the LHC

    A. Flórez🇨🇴 · J. Jones-Pérez🇵🇪 · A. Gurrola🇺🇸 · C. Rodriguez🇨🇴 · J. Peñuela-Parra🇨🇴

    Leptoquarks (LQs) are hypothetical particles that appear in various extensions of the Standard Model (SM) that can explain observed differences between SM theory predictions and experimental results. The production of these particles has been widely studied at various experiments, most recently at the Large Hadron Collider (LHC), and stringent bounds have been placed on their masses and couplings, assuming the simplest beyond-SM (BSM) hypotheses. However, the limits are significantly weaker for LQ models with family non-universal couplings containing enhanced couplings to third-generation fermions. We present a new study on the production of a LQ at the LHC, with preferential couplings to third-generation fermions, considering proton-proton collisions at $\sqrt{s}=13$ $\mathrm{TeV}$ and $\sqrt{s}=13.6$ $\mathrm{TeV}$. Such a hypothesis is well motivated theoretically and it can explain the recent anomalies in the precision measurements of $\mathrm{B}$-meson decay rates, specifically the $R_{D^{(\ast )}}$ ratios. Under a simplified model where the LQ masses and couplings are free parameters, we focus on cases where the LQ decays to a $\tau$ lepton and a $\mathrm{b}$ quark, and study how the results are affected by different assumptions about chiral currents and interference effects with other BSM processes with the same final states, such as diagrams with a heavy vector boson, ${\mathrm{Z}}^{{}^{\prime }}$. The analysis is performed using machine learning techniques, resulting in an increased discovery reach at the LHC, allowing us to probe new physics phase space which addresses the $\mathrm{B}$-meson anomalies, for $\mathrm{LQ}$ masses up to 5.00 $\mathrm{TeV}$, for the high luminosity LHC scenario.

    hep-phEPJC(2023)·12 citations
15. 15*

    Glauber Phases in Non-Global LHC Observables: Resummation for Quark-Initiated Processes

    Philipp Böer🇩🇪 · Matthias Neubert🇩🇪 · Michel Stillger (JGU Mainz)🇩🇪

    It has been known for many years that jet cross sections at hadron colliders exhibit double-logarithmic corrections starting at four-loop order, arising from two soft Glauber-gluon interactions between the two colliding partons. The resummation of these "super-leading logarithms" has been achieved only recently by means of a renormalization-group treatment in soft-collinear effective theory. We generalize this result and, within the same framework and for quark-initiated processes, resum the double logarithms arising in the presence of an arbitrary number of Glauber-gluon exchanges. For typical choices of parameters, the higher-order Glauber terms give rise to corrections which are expected to be numerically of the same magnitude as the super-leading logarithms. However, we find that the Glauber series for jet cross sections is dominated by the two-Glauber contribution, if the colliding partons are quarks or anti-quarks.

    hep-phhep-thJHEP(2023)·13 citations
16. 16*

    Parton showering with higher-logarithmic accuracy for soft emissions

    Silvia Ferrario Ravasio🇨🇭 · Keith Hamilton🇬🇧 · Alexander Karlberg🇨🇭 · Gavin P. Salam🇬🇧 · Ludovic Scyboz🇬🇧 · Gregory Soyez🇫🇷

    The accuracy of parton-shower simulations is often a limiting factor in the interpretation of data from high-energy colliders. We present the first formulation of parton showers with accuracy one order beyond state-of-the-art next-to-leading logarithms, for classes of observable that are dominantly sensitive to low-energy (soft) emissions, specifically non-global observables and subjet multiplicities. This represents a major step towards general next-to-next-to-leading logarithmic accuracy for parton showers.

    hep-phPRL(2023)·67 citations
17. 17*

    Flavour hierarchies from emergent fundamental partial compositeness

    Florian Goertz🇩🇪 · Álvaro Pastor-Gutiérrez🇩🇪 · Jan M. Pawlowski🇩🇪

    Composite Higgs extensions of the Standard Model provide an explanation for the large hierarchies between the Yukawa couplings. We study their realisation in the context of fundamental partial compositeness where the Standard Model fermions mix linearly with bound states of the new sector, consisting of a fermion and a scalar. The properties of this composite are unravelled with the functional renormalisation group approach using dynamically emergent composites. Specifically, we extract the scaling of correlation functions and provide indicative estimates for the minimal incarnation of the theory.

    hep-phhep-thPRD(2023)·8 citations
18. 18*

    A $\nu$ window onto leptoquarks?

    Matthew Kirk🇪🇸 · Shohei Okawa🇪🇸 · Keyun Wu🇪🇸

    Upcoming neutrino telescopes promise a new window onto the interactions of neutrinos with matter at ultrahigh energies ($E_{\nu }=10^7$-$10^{10}$ GeV), and the possibility to detect deviations from the Standard Model predictions. In this paper, we update previous predictions for the enhancement of the neutrino-nucleon cross-section for motivated leptoquark models and show the latest neutrino physics bound, as well as analyse the latest LHC pair production and Drell-Yan data, and flavour constraints (some of which were previously missed). We find that, despite the next generation of neutrino experiments probing the highest energies, they will not be enough to be competitive with collider searches.

    hep-phastro-ph.HEhep-exJHEP(2023)·6 citations
19. 19*

    Exploring the impact of high-precision top-quark pair production data on the structure of the proton at the LHC

    Alim Ablat🇨🇳 · Marco Guzzi🇺🇸 · Keping Xie🇺🇸 · Sayipjamal Dulat🇨🇳 · Tie-Jiun Hou🇨🇳 · Ibrahim Sitiwaldi🇨🇳 · C.-P. Yuan🇺🇸

    The impact of recent LHC top-quark pair production single differential cross section measurements at 13 TeV collision energy on the structure of the proton is explored. In particular, the impact of these high-precision data on the gluon and other parton distribution functions (PDFs) of the proton at intermediate and large partonic momentum fraction $x$ is analyzed. This study extends the CT18 global analysis framework to include these new data. The interplay between top-quark pair and inclusive jet production as well as other processes at the LHC, is studied. In addition, a study of the impact of scale choice on the theory description of the new 13 TeV $t\bar{t}$ measurements is performed.

    hep-phPRD(2024)·18 citations
20. 20*

    Topportunities at the LHC: Rare Top Decays with Light Singlets

    Henning Bahl🇺🇸 · Seth Koren🇺🇸 · Lian-Tao Wang🇺🇸

    The discovery of the top quark, the most massive elementary particle yet known, has given us a distinct window into investigating the physics of the Standard Model and Beyond. With a plethora of top quarks to be produced in the High Luminosity era of the LHC, the exploration of its rare decays holds great promise in revealing potential new physics phenomena. We consider higher-dimensional operators contributing to top decays in the SMEFT and its extension by a light singlet species of spin 0, 1/2, or 1, and exhibit that the HL-LHC may observe many exotic top decays in a variety of channels. Light singlets which primarily talk to the SM through such a top interaction may also lead to distinctive long-lived particle signals. Searching for such long-lived particles in top-quark decays has the additional advantage that the SM decay of the other top quark in the same event provides a natural trigger.

    hep-phhep-exEPJC(2024)·10 citations
21. 21*

    The Interplay of Machine Learning--based Resonant Anomaly Detection Methods

    Tobias Golling🇨🇭 · Gregor Kasieczka🇩🇪 · Claudius Krause🇩🇪 · Radha Mastandrea🇺🇸 · Benjamin Nachman🇺🇸 · John Andrew Raine🇨🇭 · Debajyoti Sengupta🇨🇭 · David Shih🇺🇸 · Manuel Sommerhalder🇩🇪

    Machine learning--based anomaly detection (AD) methods are promising tools for extending the coverage of searches for physics beyond the Standard Model (BSM). One class of AD methods that has received significant attention is resonant anomaly detection, where the BSM is assumed to be localized in at least one known variable. While there have been many methods proposed to identify such a BSM signal that make use of simulated or detected data in different ways, there has not yet been a study of the methods' complementarity. To this end, we address two questions. First, in the absence of any signal, do different methods pick the same events as signal-like? If not, then we can significantly reduce the false-positive rate by comparing different methods on the same dataset. Second, if there is a signal, are different methods fully correlated? Even if their maximum performance is the same, since we do not know how much signal is present, it may be beneficial to combine approaches. Using the Large Hadron Collider (LHC) Olympics dataset, we provide quantitative answers to these questions. We find that there are significant gains possible by combining multiple methods, which will strengthen the search program at the LHC and beyond.

    hep-phhep-exphysics.data-anEPJC(2024)·43 citations
22. 22*

    Numerical study of multiparticle production in $\lambda {\varphi }^4$ theory

    S. Demidov🇷🇺 · B. Farkhtdinov🇷🇺 · D. Levkov🇷🇺

    We study multiparticle production in the unbroken $(3+1)$-dimensional $\lambda {\varphi }^4$ theory using the semiclassical method of singular solutions. We show that the probabilities of these processes are exponentially suppressed in terms of a small coupling constant $\lambda \ll 1$ if the multiplicity of the final state is large: $n\gg 1$. At $n\ll {\lambda }^{-1}$ the probabilities agree with well-known perturbative results. At $n\gg {\lambda }^{-1}$ they are dominated by loop effects and decrease exponentially with $n$, as we show for the first time.

    hep-phhep-thPhys.Part.Nucl.Lett.(2023)·4 citations
23. 23*

    Dynamical Tidal Response of Kerr Black Holes from Scattering Amplitudes

    M. V. S. Saketh🇺🇸 · Zihan Zhou🇺🇸 · Mikhail M. Ivanov🇺🇸

    We match scattering amplitudes in point particle effective field theory (EFT) and general relativity to extract low frequency dynamical tidal responses of rotating (Kerr) black holes to all orders in spin. In the conservative sector, we study local worldline couplings that correspond to the time-derivative expansion of the black hole tidal response function. These are dynamical (frequency-dependent) generalizations of the static Love numbers. We identify and extract couplings of three types of subleading local worldline operators: the curvature time derivative terms, the spin - curvature time derivative couplings, and quadrupole - octupole mixing operators that arise due to the violation of spherical symmetry. The first two subleading couplings are non-zero and exhibit a classical renormalization group running; we explicitly present their scheme-independent beta functions. The conservative mixing terms, however, vanish as a consequence of vanishing static Love numbers. In the non-conservative sector, we match the dissipation numbers at next-to-leading and next-to-next-to leading orders in frequency. In passing, we identify terms in the general relativity absorption probabilities that originate from tails and short-scale logarithmic corrections to the lowest order dissipation contributions.

    ↳ hep-thastro-ph.HEgr-qchep-phPRD(2024)·104 citations
24. 24*

    Two-pole nature of the $\Lambda (1405)$ from lattice QCD

    John Bulava🇩🇪 · Bárbara Cid-Mora🇩🇪 · Andrew D. Hanlon🇺🇸 · Ben Hörz🇩🇪 · Daniel Mohler🇩🇪 · Colin Morningstar🇺🇸 · Joseph Moscoso🇺🇸 · Amy Nicholson🇺🇸 · Fernando Romero-López🇺🇸 · Sarah Skinner🇺🇸 · André Walker-Loud🇺🇸

    This letter presents the first lattice QCD computation of the coupled channel $\pi \Sigma -\bar{K}N$ scattering amplitudes at energies near $1405\mathrm{MeV}$. These amplitudes contain the resonance $\Lambda (1405)$ with strangeness $S=-1$ and isospin, spin, and parity quantum numbers $I(J^P)=0(1/2^{-})$. However, whether there is a single resonance or two nearby resonance poles in this region is controversial theoretically and experimentally. Using single-baryon and meson-baryon operators to extract the finite-volume stationary-state energies to obtain the scattering amplitudes at slightly unphysical quark masses corresponding to $m_{\pi }\approx 200$ MeV and $m_K\approx 487$ MeV, this study finds the amplitudes exhibit a virtual bound state below the $\pi \Sigma$ threshold in addition to the established resonance pole just below the $\bar{K}N$ threshold. Several parametrizations of the two-channel $K$-matrix are employed to fit the lattice QCD results, all of which support the two-pole picture suggested by $SU(3)$ chiral symmetry and unitarity.

    ↳ hep-lathep-phnucl-exnucl-thPRL(2024)·77 citations
25. 25*

    Testing the assumptions of the Effective Field Theory of Large-Scale Structure

    Mandar Karandikar · Cristiano Porciani · Oliver Hahn

    The Effective Field Theory of Large-Scale Structure (EFTofLSS) attempts to amend some of the shortcomings of the traditional perturbative methods used in cosmology. It models the evolution of long-wavelength perturbations above a cutoff scale without the need for a detailed description of the short-wavelength ones. Short-scale physics is encoded in the coefficients of a series of operators composed of the long-wavelength fields, and ordered in a systematic expansion. As applied in the literature, the EFTofLSS corrects a summary statistic (such as the power spectrum) calculated from standard perturbation theory by matching it to $N$-body simulations or observations. This `bottom-up' construction is remarkably successful in extending the range of validity of perturbation theory. In this work, we compare this framework to a `top-down' approach, which estimates the EFT coefficients from the stress tensor of an $N$-body simulation, and propagates the corrections to the summary statistic. We consider simple initial conditions, viz. two sinusoidal, plane-parallel density perturbations with substantially different frequencies and amplitudes. We find that the leading EFT correction to the power spectrum in the top-down model is in excellent agreement with that inferred from the bottom-up approach which, by construction, provides an exact match to the numerical data. This result is robust to changes in the wavelength separation between the two linear perturbations. However, in our setup, the leading EFT coefficient does not always grow linearly with the cosmic expansion factor as assumed in the literature based on perturbative considerations. Instead, it decreases after orbit crossing takes place.

    ↳ astro-ph.COhep-phJCAP(2024)·5 citations
26. 26*

    Reexamining constraints on neutron star properties from perturbative QCD

    Dake Zhou🇺🇸

    The implications of perturbative QCD (pQCD) calculations on neutron stars are carefully examined. While pQCD calculations above baryon chemical potentials ${\mu }_B\simeq 2.4$ GeV demonstrate the potential of ruling out a wide range of neutron star equations of state (EOSs), such constraints only affect the most massive neutron stars in the vicinity of the Tolman-Oppenheimer-Volkoff (TOV) limit, resulting in constraints that are orthogonal to current or expected astrophysical bounds. In the most constraining scenario, pQCD considerations favor low values of the squared speed sound $C_s$ at high ${\mu }_B$ relevant for the most massive neutron stars, but leave predictions of the radii and tidal deformabilities almost unchanged. Such considerations become irrelevant if the maximum speed of sound squared inside neutron stars does not exceed about $C_{s,\max }\simeq 0.5$, or if pQCD breaks down below ${\mu }_B\simeq 2.9$ GeV. Furthermore, the large pQCD uncertainties preclude any meaningful bounds on the neutron star EOS at the moment. Interestingly, if pQCD predictions for the pressure at around ${\mu }_B\simeq 2.5$ GeV are refined and found to be low ($\lesssim 1.5$ GeV/fm${}^3$), evidence for a soft neutron star inner core EOS in combination with the existence of two-solar-mass pulsars would indicate the presence of color superconductivity beyond neutron star densities. We point out that two-solar-mass pulsars place robust upper bounds on this non-perturbative effect and require the pairing gap to be less than ${\Delta }_{\mathrm{CFL}}\lesssim 500$ MeV at ${\mu }_B\simeq 2.5$ GeV.

    ↳ astro-ph.HEhep-phnucl-thPRC(2025)·19 citations
27. 27*

    Evaluating approximate asymptotic distributions for fast neutrino flavor conversions in a periodic 1D box

    Zewei Xiong🇩🇪 · Meng-Ru Wu🇹🇼 · Sajad Abbar🇩🇪 · Soumya Bhattacharyya🇹🇼 · Manu George🇹🇼 · Chun-Yu Lin🇹🇼

    The fast flavor conversions (FFCs) of neutrinos generally exist in core-collapse supernovae and binary neutron-star merger remnants, and can significantly change the flavor composition and affect the dynamics and nucleosynthesis processes. Several analytical prescriptions were proposed recently to approximately explain or predict the asymptotic outcome of FFCs for systems with different initial or boundary conditions, with the aim for providing better understandings of FFCs and for practical implementation of FFCs in hydrodynamic modeling. In this work, we obtain the asymptotic survival probability distributions of FFCs in a survey over thousands of randomly sampled initial angular distributions by means of numerical simulations in one-dimensional boxes with the periodic boundary condition. We also propose improved prescriptions that guarantee the continuity of the angular distributions after FFCs. Detailed comparisons and evaluation of all these prescriptions with our numerical survey results are performed. The survey dataset is made publicly available to inspire the exploration and design for more effective methods applicable to realistic hydrodynamic simulations.

    ↳ astro-ph.HEhep-phPRD(2023)·63 citations
28. 28*

    Scale invariant Einstein-Cartan gravity and flat space conformal symmetry

    Georgios K. Karananas🇩🇪 · Mikhail Shaposhnikov🇨🇭 · Sebastian Zell🇧🇪

    We find the conditions under which scale-invariant Einstein-Cartan gravity with scalar matter fields leads to an approximate conformal invariance of the flat space particle theory up to energies of the order of the Planck mass. In the minimal setup, these models, in addition to the fields of the Standard Model and the graviton, contain only one extra particle -- a massless dilaton. Theories of this type can pave the way for a self-completion all the way up the Planck scale and lead to rather universal inflationary predictions, close to those of the simplest Higgs-inflation scenario in the metric theory of gravity.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2023)·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.