HEP Phenomenology·hep-ph

Fri·Dec 23, 2022Friday·December 23, 2022

46 papers—35 primary·11 cross-listed·reconstructed*

01*
Baryogenesis and Primordial Black Hole Dark Matter from Heavy Metastable Particles
Barmak Shams Es Haghi🇺🇸
We propose a novel and simple scenario to explain baryon asymmetry and dark matter (DM) by utilizing an early matter-dominated era (EMDE) caused by a heavy metastable particle. Within the EMDE, lack of pressure enhances the formation of primordial black holes (PBHs) which can then contribute to the relic abundance of DM. The eventual decay of heavy metastable particle that has baryon number and $C P$ violating interactions reheats the Universe and gives rise to baryon asymmetry. Since in this setup, PBH serves as a DM candidate, the particle physics model may not require new stable degrees of freedom which leads to more freedom in the model-building side. As an example, we show that a modulus field which dominates the energy density of the Universe prior to its decay, may explain both DM and baryon asymmetry in the Universe in the context of the Minimal Supersymmetric Standard Model (MSSM) while the lightest superparticle is not stable and cannot be a DM candidate due to the R-parity violating interactions needed for baryogenesis.
hep-phastro-ph.COPRD(2023)·13 citations
02*
Lepton universality in a model with three generations of sterile Majorana neutrinos
M. N. Dubinin🇷🇺 · D. M. Kazarkin🇷🇺
The extension of the Standard Model lepton sector by three right-handed Majorana neutrinos (heavy neutral leptons, HNL) with masses up to GeV scale is considered. While the lightest HNL is the dark matter particle with mass of the order of 5 keV, the remaining two HNLs ensure standard (active) neutrino mass generation by means of the see-saw type I mechanism. Two heavy sterile neutrinos with quasi-degenerate masses up to 5 GeV can induce the deviation of lepton universality violation parameter in the decays of $π^{\pm}$ and $K^{\pm}$ mesons from the the Standard Model value. Contours are obtained for the permissible values of this parameter within the framework of two mixing scenarios, taking into account the lifetime boundary for heavy neutral lepton from Big Bang nucleosynthesis in the Universe. When calculating the HNL decay width in the framework of the model with six Majorana neutrinos, three active and three heavy, both two-particle and three-particle lepton decays, essential for masses below the mass of the pion, were taken into account. When calculating the decay widths, the limiting case known as the "Dirac limit" is not used. The results based on the explicit form of mixing matrices for three HNL generations and the diagram technique for Majorana neutrinos, which explicitly take into account the interference terms for diagrams with identical mass states, can lead to some differences in lifetime from the results using the "Dirac limit" and the displacement of the corresponding experimental exclusion contours of the "mass-mixing" type. For the second mixing scenario, a mass region of $460 MeV < M < 485$ MeV has been found that allows violation of lepton universality in charged kaon decays at the level observed in the experiment.
hep-phPRD(2024)·3 citations
03*
Non-supersymmetric SO(10) models with Gauge and Yukawa coupling unification
Abdelhak Djouadi🇪🇸 · Renato Fonseca🇪🇸 · Ruiwen Ouyang🇪🇪 · Martti Raidal🇪🇪
We study a non-supersymmetric SO(10) Grand Unification Theory with a very high energy intermediate symmetry breaking scale in which not only gauge but also Yukawa coupling unification are enforced via suitable threshold corrections and matching conditions. For gauge unification, we focus on a few symmetry breaking patterns with the intermediate gauge groups $SU (4)_{C} \times SU (2)_{L} \times SU (2)_{R}$ (Pati-Salam) and $SU (3)_{C} \times SU (2)_{L} \times SU (2)_{R} \times U (1)_{B - L}$ (minimal left-right symmetry) assuming an additional global U(1) Peccei--Quinn symmetry, and having the Standard Model supplemented by a second Higgs doublet field at the electroweak scale. We derive the conditions as well as the approximate analytical solutions for the unification of the gauge coupling constants at the two-loop level and discuss the constraints from proton decay on the resulting high scale. Specializing to the case of the Pati-Salam intermediate breaking pattern, we then impose also the unification of the Yukawa couplings of third generation fermions at the high scale, again at the two-loop level. In the considered context, Yukawa unification implies a relation between the fermion couplings to the 10- and 126-dimensional scalar representations of the SO(10) group. We consider one such possible relation which is obtainable in an $E_{6}$ model where the previous two scalar fields are part of a single multiplet. Taking into account some phenomenological features such as the absence of flavor changing neutral currents at tree-level, we derive constraints on the parameters of the low energy model, in particular on the ratio of the two Higgs doublets vacuum expectation values $tan β$ .
hep-phEPJC(2023)·15 citations
04*
BSM and SM signals and backgrounds in Far-Forward Experiments at the LHC
M.V. Garzelli🇩🇪
Two far-forward experimental systems are currently taking data during Run 3 at the Large Hadron Collider (LHC): FASER + FASER $ν$ and SND@LHC. They are sensitive to some classes of beyond-the-Standard Model (BSM) particles, muons and neutrinos produced in the ATLAS interaction point (IP) and propagating for several hundred meters along the tangent to the accelerator beamline, up to the caverns where they are respectively located, in opposite directions with respect to the IP. Proposals are being prepared to extend these experiments to bigger ones during the HL-LHC phase. Building a Forward Physics Facility (FPF) capable of hosting a number of far-forward experiments characterized by different detection techniques, kinematical acceptance and purpose, is a possibility also under discussion. In this contribution I discuss some of the BSM and SM signals and backgrounds at the FPF, mainly focusing on QCD-related aspects.
hep-phActa Phys.Polon.Supp.(2023)·2 citations
05*
Exploring dynamics of $A_{4}$ flavour symmetry using low scale seesaw mechanisms
Kalpana Bora🇮🇳 · Maibam Ricky Devi🇮🇳
Low scale seesaw models, like low scale type II, inverse (ISS), and linear seesaw (LSS) models provide an interesting mechanism to obtain light neutrino masses and mixings, as they can be tested in future TeV scale experiments. Discrete flavour symmetry groups like $A_{4}$ can be incorporated to explain the flavour structure of particles. But, so far, nothing is known about dynamics of flavour symmetry - scale of its breaking, or VEV alignment of the flavon fields. In a recent study [1], we have investigated and shed light on how to pinpoint the favoured VEV alignment of the flavon field using light neutrino oscillation data. In this work, for the first time, we present an analysis on dependence of light neutrino masses on scale of flavon VEV in these three seesaw models, and comment on how this information can be used to discriminate among them. We also discuss about the estimated value of the constant $F$ which can constrain various coupling constants of the model, cut-off scale of the theory and scale of flavour symmetry breaking. This study can provide useful insight into the hitherto unknown dynamics of flavour symmetry and hence can contribute as an important ingredient in the model building for future studies.
hep-phPhys.Part.Nucl.Lett.(2022)·3 citations
06*
Local spatial densities for composite spin-3/2 systems
H. Alharazin🇩🇪 · B.-D. Sun🇨🇳 · E. Epelbaum🇩🇪 · J. Gegelia🇩🇪 · U.-G. Meißner🇩🇪
The definition of local spatial densities by using sharply localized one-particle states is applied to spin-3/2 systems. Matrix elements of the electromagnetic current and the energy-momentum tensor are considered and integral expressions of associated spatial distributions in terms of form factors are derived.
hep-phhep-exhep-latJHEP(2023)·16 citations
07*
Role of the scalar $f_{0} (980)$ in the process $D_{s}^{+} \to π^{+} π^{0} π^{0}$
Han Zhang🇨🇳 · Yun-He Lyu🇨🇳 · Li-Juan Liu🇨🇳 · En Wang🇨🇳
Based on the BESIII measurements on the reaction of $D_{s}^{+} \to π^{+} π^{0} π^{0}$ , we investigate this process by considering the $S$ -wave pseudoscalar-pseudoscalar interaction within the unitary chiral approach, and the contributions from the intermediate resonances $f_{0} (1370)$ and $f_{2} (1270)$ . Our calculation could reasonably reproduce the experimental data, and our results imply that the $f_{0} (980)$ , dynamically generated from the $S$ -wave pseudoscalar-pseudoscalar interaction, plays an important role in this process, and the contributions from the intermediate resonances $f_{0} (1370)$ and $f_{2} (1270)$ are also necessary. The more precise measurements of this process in future could shed light on the nature of the $f_{0} (1370)$ and $f_{2} (1270)$ .
hep-phCPC(2023)·17 citations
08*
Peaky Production of Light Dark Photon Dark Matter
Yuichiro Nakai🇨🇳 · Ryo Namba🇯🇵 · Ippei Obata🇩🇪
We explore a mechanism to produce a light dark photon dark matter through a coupling between the dark photon field and a spectator scalar field which plays no role in the inflationary expansion of the Universe while rolling down its potential during the inflation. The motion of the spectator field efficiently produces dark photons with large wavelengths which become non-relativistic before the time of matter-radiation equality. The spectrum of the wavelengths is peaky so that the constraint from the isocurvature perturbation can be evaded. The correct relic abundance is then achieved over a wide range of the dark photon mass down to $1 0^{- 13} eV$ . Our mechanism favors high-scale inflation models which can be tested in future observations. Furthermore, fluctuations of the dark photon field during inflation produce gravitational waves detectable at future space-based interferometers and/or pulsar timing array experiments.
hep-phastro-ph.COgr-qchep-thJCAP(2023)·14 citations
09*
Uncovering tau leptons-enriched semi-visible jets at the LHC
Hugues Beauchesne🇹🇼 · Cesare Cazzaniga🇨🇭 · Annapaola de Cosa🇨🇭 · Caterina Doglioni🇬🇧 · Tobias Fitschen🇬🇧 · Giovanni Grilli di Cortona🇮🇹 · Ziyuan Zhou🇨🇭
This Letter proposes a new signature for confining dark sectors at the Large Hadron Collider. Under the assumption of a QCD-like hidden sector, hadronic jets containing stable dark bound states could manifest in proton-proton collisions. We present a simplified model with a $Z^{'}$ boson yielding the production of jets made up of dark bound states and subsequently leading to the decays of those that are unstable to $τ$ leptons and Standard Model quarks. The resulting signature is characterised by non-isolated $τ$ lepton pairs inside semi-visible jets. We estimate the constraints on our model from existing CMS and ATLAS analyses. We propose a set of variables that leverage the leptonic content of the jet and exploit them in a supervised jet tagger to enhance the signal-to-background separation. Furthermore, we discuss the performance and limitations of current triggers for accessing sub-TeV $Z^{'}$ masses, as well as possible strategies that can be adopted by experiments to access such low mass regions. We estimate that with the currently available triggers, a high mass search can claim a $5 σ$ discovery (exclusion) of the $Z^{'}$ boson with a mass up to 4.5TeV (5.5TeV) with the full Run2 data of the LHC when the fraction of unstable dark hadrons decaying to $τ$ lepton pairs is around $50%$ , and with a coupling of the $Z^{'}$ to right-handed up-type quarks of 0.25. Furthermore, we show that, with new trigger strategies for Run3, it may be possible to access $Z^{'}$ masses down to 700 GeV, for which the event topology is still composed of two resolved semi-visible jets.
hep-phEPJC(2023)·16 citations
10*
Worldline instantons for the momentum spectrum of Schwinger pair production in space-time dependent fields
Gianluca Degli Esposti🇩🇪 · Greger Torgrimsson🇸🇪
We show how to use the worldline-instanton formalism to calculate the momentum spectrum of the electron-positron pairs produced by an electric field that depends on both space and time. Using the LSZ reduction formula with a worldline representation for the propagator in a spacetime field, we make use of the saddle-point method to obtain a semiclassical approximation of the pair-production spectrum. In order to check the final result, we integrate the spectrum and compare with the results obtained using a previous instanton method for the imaginary part of the effective action.
hep-phhep-thPRD(2023)·23 citations
11*
Constraining the Georgi-Machacek Model with a Light Higgs
Amine Ahriche (U. Sharjah, UAE)🇦🇪
In this work, we investigate the viability of a light Higgs ( $η$ ) scenario in the Georgi-Machacek (GM) model, where we consider all theoretical and experimental constraints such as the perturbativity, vacuum stability, unitarity, electroweak precision tests, the Higgs di-photon and undetermined decays and the Higgs total decay width. In addition, we consider more recent experimental bounds from the searches for doubly-charged Higgs bosons in the VBF channel $H_{5}^{++} \to W^{+} W^{+}$ , Drell-Yan production of a neutral Higgs boson $pp \to H_{5}^{0} (γ γ) H_{5}^{+}$ , and for the light scalars at LEP $e^{-} e^{+} \to Z η$ , and at ATLAS and CMS in different final states such as $pp \to η \to 2 γ$ and $pp \to h \to η η \to 4 γ, 2 μ 2 τ, 2 μ 2 b, 2 τ 2 b$ . By combining these bounds together, we found a parameter space region that is significant as the case of the SM-like Higgs to be the light CP-even eigenstate, and this part of the parameter space would be tightened by the coming analyses.
hep-phhep-exPRD(2023)·16 citations
12*
Boosted top tagging and its interpretation using Shapley values
Biplob Bhattacherjee🇮🇳 · Camellia Bose🇮🇳 · Amit Chakraborty🇮🇳 · Rhitaja Sengupta🇮🇳
Top tagging has emerged as a fast-evolving subject due to the top quark's significant role in probing physics beyond the standard model. For the reconstruction of top jets, machine learning models have shown a substantial improvement in the classification performance compared to the previous methods. In this work, we build top taggers using $N$ -Subjettiness ratios and several Energy Correlation observables as input features to train the eXtreme Gradient BOOSTed decision tree (XGBOOST). The study finds that tighter parton-level matching lead to more accurate tagging. However, in real experimental data, where the parton level data are unknown, this matching cannot be done. We train the XGBOOST models without performing this matching and show that this difference impacts the taggers' effectiveness. Additionally, we test the tagger under different simulation conditions, including changes in center-of-mass energy, parton distribution functions (PDFs), and pileup effects, demonstrating its robustness with performance deviations of less than 1%. Furthermore, we use the SHapley Additive exPlanation (SHAP) framework to calculate the importance of the features of the trained models. It helps us to estimate how much each feature of the data contributed to the model's prediction and what regions are of more importance for each input variable. Finally, we combine all the tagger variables to form a hybrid tagger and interpret the results using the Shapley values.
hep-phhep-exEur.Phys.J.Plus(2024)·21 citations
13*
Precision calculations of $B_{d, s} \to π, K$ decay form factors in soft-collinear effective theory
Bo-Yan Cui🇨🇳 · Yong-Kang Huang🇨🇳 · Yue-Long Shen🇨🇳 · Chao Wang🇨🇳 · Yu-Ming Wang🇨🇳
We improve QCD calculations of the $B_{d, s} \to π, K$ form factors at large hadronic recoil by implementing the next-to-leading-logarithmic resummation for the obtained leading-power light-cone sum rules in the soft-collinear effective theory (SCET) framework. Additionally, we endeavour to investigate a variety of the subleading-power contributions to these heavy-to-light form factors at $O (α_{s}^{0})$ , by including the higher-order terms in the heavy-quark expansion of the hard-collinear quark propagator, by evaluating the desired effective matrix element of the next-to-leading-order term in the $SCE T_{I}$ representation of the weak transition current, by taking into account the off-light-cone contributions of the two-body heavy-quark effective theory matrix elements as well as the three-particle higher-twist corrections from the subleading bottom-meson light-cone distribution amplitudes, and by computing the twist-five and twist-six four-body higher-twist effects with the aid of the factorization approximation. Having at our disposal the SCET sum rules for the exclusive $B$ -meson decay form factors, we further explore in detail numerical implications of the newly computed subleading-power corrections by employing the three-parameter model for both the leading-twist and higher-twist $B$ -meson distribution amplitudes. Taking advantage of the customary Bourrely-Caprini-Lellouch parametrization for the semileptonic $B_{d, s} \to π, K$ form factors, we then determine the correlated numerical results for the interesting series coefficients, by carrying out the simultaneous fit of the exclusive $B$ -meson decay form factors to both the achieved SCET sum rule predictions and the available lattice QCD results.
hep-phhep-exhep-latJHEP(2023)·66 citations
14*
On macroscopic residual QCD force of electrodynamics
Martin Spousta🇨🇿
We explore a connection between virtual particles of quantum electrodynamics and quantum chromodynamics (QCD) which is predicted to give rise to a residual attractive interaction measurable as a macroscopic force. We calculate the asymptotic behavior of relevant scattering amplitudes, perform their resummation, and analyze the sign of the resulting interaction. Then, we calculate the primary experimentally observable consequences of this Standard Model force. We discuss the impact of this force at terrestrial scales and at astrophysical scales. In particular, we quantify the impact of this force on the warm ionized medium present in galaxies and the intracluster medium present in cluster of galaxies.
hep-phEur.Phys.J.Plus(2024)·0 citations
15*
Multi muon/anti-muon signals via productions of gauge and scalar bosons in a $U (1)_{L_{μ} - L_{τ}}$ model at muonic colliders
Arindam Das🇯🇵 · Takaaki Nomura🇨🇳 · Takashi Shimomura🇯🇵
We discuss the discovery potential of a promising signals, $3 \times μ^{+} μ^{-}$ at a $μ^{+} μ^{-}$ collider and $μ^{+} μ^{+} μ^{+} μ^{+} μ^{-} μ^{-}$ at a $μ^{+} μ^{+}$ collider, that are obtained via production of $Z^{'}$ and a new scalar boson $ϕ$ in a spontaneously broken local $U (1)_{L_{μ} - L_{τ}}$ model. We consider the $Z^{'}$ associated production from the process $μ^{+} μ^{-} \to ϕ Z^{'}$ in addition to a muonphilic $Z^{'}$ fusion process $μ^{+} μ^{\pm} \to ϕ μ^{+} μ^{\pm}$ . The scalar boson is associated with $U (1)_{L_{μ} - L_{τ}}$ symmetry breaking and dominantly decays into $Z^{'} Z^{'}$ mode. We carry out numerical simulation analysis for signal and background processes to estimate a discovery significance for different benchmark points. It is shown that our signal can be observed with integrated luminosity less than $O (100)$ fb $^{- 1}$ for both $μ^{+} μ^{-}$ and $μ^{+} μ^{+}$ colliders with more than 5- $σ$ significance.
hep-phhep-exEPJC(2023)·21 citations
16*
Some new observations for the Georgi-Machacek scenario with triplet Higgs
Rituparna Ghosh🇮🇳 · Biswarup Mukhopadhyaya🇮🇳
The Georgi-Machacek model, introducing a complex and a real scalar triplet as additional components of the electroweak symmetry breaking sector, enables substantial triplet contributions to the weak gauge boson masses, subject to the equality of the complex and the real triplet vacuum expectation values (vev) via a custodial SU(2) symmetry. We present an updated set of constraints on this scenario, from collider data (including those from 137/139~fb $^{- 1}$ of luminosity at the Large Hadron Collider), available data on the 125-GeV scalar, indirect limits and also theoretical restrictions from vacuum stability and unitarity. It is found that some bounds get relaxed, and the phenomenological potential of the scenario is more diverse, if the doubly charged scalar in the spectrum can decay not only into two like-sign $W$ 's but also into one or two singly charged scalars. Other interesting features are noticed in a general approach, such as substantial $γ γ$ and $Z γ$ branching ratios of the additional custodial singlet scalar, and appreciable strength of the trilinear interaction of a charged scalar, the $W$ and the $Z$ . Finally,, we take into account the possibility of custodial SU(2) breaking, resulting in inequality of the real and the complex scalar vevs which too in principle may allow large triplet contribution to weak boson masses. Illustrative numerical results on the modified limits and predictions are presented, once more taking into account all the constraints mentioned above.
hep-phPRD(2023)·13 citations
17*
Light Higgs boson in the NMSSM confronted with the CMS diphoton and ditau excesses
Weichao Li🇨🇳 · Haoxue Qiao🇨🇳 · Jingya Zhu🇨🇳
In 2018, the CMS collaboration reported a di-photon excess around 95.3 GeV with a local significance of 2.8 $σ$ . Interestingly, the CMS collaboration also reported a di-tau excess recently at 95 $\sim$ 100 GeV with a local significance of 2.6 $\sim$ 3.1 $σ$ . Besides, a $b b ˉ$ excess at 98 GeV with a 2.3 $σ$ local significance was reported with LEP data about twenty years ago. In this work, we consider interpreting these excesses together with a light Higgs boson in the next-to-minimal supersymmetric standard model (NMSSM). We conclude that in NMSSM the 95 $\sim$ 100 GeV excesses are difficult to be satisfied simultaneously (not possible globally at $1 σ$ level, or simultaneously at $2 σ$ level), and we analyze two partial-satisfied scenarios: the globally $2 σ$ scenario and small di-photon scenario. An approximate equation of global fit to the three excesses is derived, and two representative types of surviving samples are analyzed in detail. Since the mass regions of these excesses are near the Z boson, we also consider checking the light Higgs boson in the $t t ˉ$ -associated channels. The detailed results may be useful for further checking the low-mass-region excesses in the future.
hep-phhep-exCPC(2023)·46 citations
18*
Dynamics of quarks and gauge fields in the lowest-energy states in QCD and QED
Andrew V. Koshelkin🇷🇺 · Cheuk-Yin Wong🇺🇸
The dynamics of quarks and gauge fields in the lowest energy states in QCD and QED interactions is studied by compactifying the (3+1)D space-time to the (1+1)D space-time with cylindrical symmetry and by combining Schwinger's longitudinal confinement in (1+1)D with Polyakov's transverse confinement in (2+1)D. Using the action integral, we separate out the transverse and longitudinal degrees of freedom. By solving the derived transverse and longitudinal equations, we study the QCD and QED collective excitations. In addition to the well known QCD low-energy states, we find stable collective QED excitations showing up as massive QED-confined mesons, in support of previous studies. In particular, the masses of the recently observed X17 particle at about 17 MeV and the E38 particle at about 38 MeV are calculated in the developed approach, in good agreement with experimental results.
hep-phnucl-thPoS·2 citations
19*
Analysis of rescattering effects in $3 π$ final states
Dominik Stamen🇩🇪 · Tobias Isken🇩🇪 · Bastian Kubis🇩🇪 · Mikhail Mikhasenko🇩🇪 · Malwin Niehus🇩🇪
Decays into three particles are often described in terms of two-body resonances and a non-interacting spectator particle. To go beyond this simplest isobar model, crossed-channel rescattering effects need to be accounted for. We quantify the importance of these rescattering effects in three-pion systems for different decay masses and angular-momentum quantum numbers. We provide the amplitude decompositions for four decay processes with total $J^{P C} = 0^{--}$ , $1^{--}$ , $1^{-+}$ , and $2^{++}$ , all of which decay predominantly as $ρ π$ states. Two-pion rescattering is described in terms of an Omnès function, which incorporates the $ρ$ resonance. Inclusion of crossed-channel effects is achieved by solving the Khuri-Treiman integral equations. The unbinned log-likelihood estimator is used to determine the significance of the rescattering effects beyond two-body resonances; we compute the minimum number of events necessary to unambiguously find these in future Dalitz-plot analyses. Kinematic effects that enhance or dilute the rescattering are identified for the selected set of quantum numbers and various masses.
hep-phhep-exnucl-thEPJC(2023)·25 citations
20*
Unobservability of the topological charge in nonabelian gauge theory: Ward-Takahashi identity and phenomenological aspects
Nodoka Yamanaka🇯🇵
We argue that the topological charge of nonabelian gauge theory is unphysical. To show this statement, we use the Adler-Bardeen theorem and the Becchi-Rouet-Stora-Tyutin symmetry which are warranted by the perturbative finiteness of the chiral anomaly, thus being free of Gribov ambiguity. In addition to the original argument using the unphysical gauge field component collinear to the spatial derivative of the gauge function, we show the unobservability of the topological charge using the Ward-Takahashi identity. We then present the consequences of this finding and show the consistency with many physical pictures and ideas that have been developed around the topology of nonabelian gauge theory. The most important ones are the resolution of the Strong CP problem, the unobservability of topological instantons, the physical relevance of the axial $U (1)$ symmetry, the independence of the vacuum energy on the vacuum angle, and the impossibility to realize the sphaleron induced baryogenesis and chiral magnetic effects. The axial $U (1)$ symmetry and the unphysical $θ$ -term imply that the physical complex phase of the Cabibbo-Kobayashi-Maskawa matrix is the sole source of CP violation in the standard model. The unphysical sphaleron also means that the lepton number is phenomenologically free from the baryon number, and their violations may be modeled separately. We also comment on the consistency with the results of lattice calculations.
hep-phhep-lathep-thnucl-th16 citations
21*
Mesonic "screening masses" in high temperature QCD
Edward Shuryak🇺🇸
Lattice studies of QCD at high temperature has investigated the so called ``screening masses", corresponding to quark-antiquark states propagating in $s p a t ia l$ (rather than time) direction. Thirty years ago we pointed out that those should correspond to states of 2+1 dimensional quarkonia, and in this work we show that this correspondence provide quantitative description of the lattice data.
hep-phhep-lat1 citation
22*
Electroweak corrections to $g + g \to H_{l, h}$ and $H_{l, h} \to γ + γ$ in the Higgs-singlet extension of the Standard model
Christian Sturm🇩🇪 · Benjamin Summ🇩🇪 · Sandro Uccirati🇮🇹
We calculate the next-to-leading order electroweak corrections for Higgs-boson production in gluon fusion and the Higgs-boson decay into two photons or gluons in the real Higgs-singlet extension of the Standard model (HSESM). For the light Higgs-boson of the HSESM the electroweak corrections for these processes are of the same order of magnitude as in the Standard model. For the heavy Higgs-boson of the HSESM the electroweak corrections can become large depending on the considered scenario.
hep-phJHEP(2023)·3 citations
23*
Multiple Mellin-Barnes integrals with straight contours
Sumit Banik🇮🇳 · Samuel Friot🇫🇷
We show how the conic hull method, recently developed for the analytic and non-iterative evaluation of multifold Mellin-Barnes (MB) integrals, can be extended to the case where these integrals have straight contours of integration parallel to the imaginary axes in the complex planes of the integration variables. MB integrals of this class appear, for instance, when one computes the $ϵ$ -expansion of dimensionally regularized Feynman integrals, as a result of the application of one of the two main strategies (called A and B in the literature) used to resolve the singularities in $ϵ$ of MB representations. We upgrade the Mathematica package MBConicHulls.wl which can now be used to obtain multivariable series representations of multifold MB integrals with arbitrary straight contours, providing an efficient tool for the automatic computation of such integrals. This new feature of the package is presented, along with an example of application by calculating the $ϵ$ -expansion of the dimensionally regularized massless one-loop pentagon integral in general kinematics and $D = 4 - 2 ϵ$ .
hep-phhep-thmath-phmath.MPPRD(2023)·16 citations
24*
Two-loop evolution kernels for colour dependent double parton distributions
Markus Diehl🇩🇪 · Florian Fabry🇩🇪 · Alexey Vladimirov🇪🇸
A key ingredient in the description of double parton distributions is their scale dependence. If the colour of each individual parton is summed over, the distributions evolve with the same DGLAP kernels as ordinary parton distributions. This is no longer true if the two partons are colour correlated. We compute the relevant kernels for this case at next-to-leading order in the strong coupling, for unpolarised or longitudinally polarised partons and for transversely polarised quarks.
hep-phJHEP(2023)·7 citations
25*
Enhancing charge ratio sensitivity to hadronization effects via jet selections on resolved SoftDrop splitting
Liliana Apolinário🇵🇹 · Raghav Kunnawalkam Elayavalli🇺🇸 · Nuno Olavo Madureira🇵🇹
The study of Quantum Chromodynamics (QCD) at ultra-relativistic energies can be performed in a controlled environment through lepton-hadron deep inelastic scatterings. In such collisions, the high-energy partonic emissions that follow from the ejected hard partons are accurately described by perturbative QCD. However, the lower energy scales at which quarks and gluons experience colour confinement, i.e. hadronization mechanism, fall outside the validity regions for perturbative calculations, requiring phenomenological models tuned to data to describe it. As such, hadronization physics cannot be currently derived from first principles alone. Monte Carlo event generators are useful tools to describe these processes as they simulate both the perturbative and the non-perturbative interactions, with model-dependent energy scales that control parton dynamics. This work employs jets - experimental reconstructions of final-state particles likely to have a common partonic origin - to inspect this transition further. Although originally proposed to circumvent hadronization effects, we show that jets can be utilised as probes of non-perturbative phenomena via their substructure. The charge correlation ratio was recently shown to be sensitive to hadronization effects. Our work further improves this sensitivity to non-perturbative scales by introducing a new selection based on the relative placement of the \textit{resolved SoftDrop splitting} within the clustering tree, defined as the unclustering that resolves the jet's leading charged particles.
hep-phPRD(2025)·3 citations
26*
Dark $S U (2) \to Z_{3} \times Z_{2}$ Gauge Symmetry
Debasish Borah🇮🇳 · Ernest Ma🇺🇸 · Dibyendu Nanda🇰🇷
The dark sector is postulated to be invariant under an $S U (2)$ gauge symmetry, spontaneously broken by a Higgs quadruplet to a conserved residual $Z_{3} \times Z_{2}$ symmetry. The resulting dark matter phenomenology is studied.
hep-phPLB(2023)·6 citations
27*
Towards a Unified Model of Neutrino-Nucleus Interactions
Omar Benhar🇮🇹 · Camillo Mariani🇺🇸
The achievement of the goals of the ongoing and future accelerator-based neutrino experiments - notably the determination of CP violating phase in the lepton sector - will require the development of advanced models of neutrino-nucleus interactions. In this review, we summarise the present status of experimental studies of neutrino-nucleus scattering, and discuss the developments and perspectives of the theoretical approach based on factorisation of the nuclear cross section, which has recently emerged as a promising framework for the description of the variety of processes contributing to the detected signals.
hep-phhep-exnucl-thEPJA(2023)·3 citations
28*
Radiative decays of the charmed mesons in a modified relativistic quark model
Jie-Lin Li🇨🇳 · Dian-Yong Chen🇨🇳
In the present work, we perform systematic estimations for the radiative decays of the charmed mesons in a modified relativistic quark model. Our estimations indicate that the branching ratios of the process of $D_{2}^{0} (1^{3} P_{2}) \to D^{* 0} (1^{3} S_{1}) γ$ , $D_{3}^{0} (1 D_{3}) \to D_{2}^{0} (1^{3} P_{2}) γ$ , $D_{2}^{0} (2 D_{2}^{'}) \to D_{1}^{0} (2 P_{1}) γ$ , $D_{3}^{0} (2^{3} D_{3}) \to D_{2}^{0} (2^{3} P_{2}) γ$ , and $D^{* 0} (1^{3} S_{1}) \to D^{0} (1^{1} S_{0}) γ$ are of the order of $1 0^{- 2}$ , which are sizable to be detected experimentally. Moreover, the branching ratios of some channels, for example, $D_{1}^{0} (1 P_{1}) \to D (1^{1} S_{0})^{0} γ$ , $D^{0} (3^{1} S_{0}) \to D_{1}^{'0} (2 P_{1}^{'}) γ$ and $D^{0} (3^{3} S_{1}) \to D_{2}^{0} (2^{3} P_{2}) γ$ are estimated to be of the order of $1 0^{- 3}$ , which may be accessible with the accumulation of data in future experiments.
hep-phCPC(2022)·8 citations
29*
Going all the way in the search for WIMP dark matter at the muon collider through precision measurements
Roberto Franceschini🇮🇹 · Xiaoran Zhao🇮🇹
Dark Matter is a necessary ingredient for a complete theory of Nature, which has so far remained elusive in laboratory searches for new particles. Searches at current and future colliders are in principle a promising way to search for electroweak charged dark matter particles, but the sensitivity of experiments at the LHC and future $pp$ colliders falls short to fully probe the whole mass range allowed for electroweak charged dark matter particles, which extends in principle up to the O(0.1) PeV. In this work we examine the effect of on-shell and off-shell propagation of electroweak charged thermal dark matter particles on integrated and differential rates of several Standard Model final states at the muon collider, considering candidates from weak 2-plet at the TeV scale up to 7-plet and 9-plet in the O(0.1) PeV ballpark. For fermionic WIMPs we find that all dark matter candidates with $n \leq 5$ , corresponding to a thermal mass up to 14~TeV, can be excluded at the high-energy muon collider for some center-of-mass energy at or below 14~TeV. For the $n > 5$ WIMPs our results show that higher energy muon colliders offer a route to conclusively probe both scalar and fermionic WIMPs off-shell production all the way up to the perturbativity bound for WIMP dark matter at O(0.1)~PeV. Our results bring WIMPs over the whole allowed mass range in the realm of collider searches and motivate research and development for the realization of a high energy muon collider.
hep-phEPJC(2023)·24 citations
30*
Dark matter from the centre of SU(N)
Michele Frigerio🇫🇷 · Nicolas Grimbaum-Yamamoto🇧🇪 · Thomas Hambye🇧🇪
A dark sector with non-abelian gauge symmetry provides a sound framework to justify stable dark matter (DM) candidates. We consider scalar fields charged under a $S U (N)$ gauge group, and show that the centre of $S U (N)$ , the discrete subgroup $Z_{N}$ also known as $N$ -ality, can ensure the stability of scalar DM particles. We analyse in some details two minimal DM models of this class, based on $S U (2)$ and $S U (3)$ , respectively. These models have non-trivial patterns of spontaneous symmetry breaking, leading to distinctive phenomenological implications. For the $S U (2)$ model these include a specific interplay of two DM states, with the same interactions but different masses, and several complementary DM annihilation regimes, either within the dark sector or through the Higgs portal. The $S U (3)$ model predicts dark radiation made of a pair of dark photons with a unique gauge coupling, as well as regimes where DM semi-annihilations become dominant and testable.
hep-phSciPost Phys.(2023)·10 citations
31*
Resonant contributions to polarized proton structure functions
A. N. Hiller Blin🇩🇪 · V. I. Mokeev🇺🇸 · W. Melnitchouk🇺🇸
Nucleon resonance contributions to the polarized proton $g_{1}$ and $g_{2}$ structure functions are computed from resonance electroexcitation amplitudes extracted from CLAS exclusive meson electroproduction data. Including resonances in the mass range up to 1.75 GeV, and taking into account the interference between excited states, we compare the resonant contributions with the polarized proton structure function and polarization asymmetry data from Jefferson Lab 6 GeV measurements. All resonance-like structure observed in the polarized structure functions and asymmetries can be attributed to the resonant contributions, confirming their essential role in the behavior of $g_{1}$ and $g_{2}$ in the resonant region over the entire range $Q^{2} < 7.5$ GeV $^{2}$ covered by the measurements. Comparing the resonance contributions with the $g_{1}$ and $g_{2}$ structure functions computed from parton distribution functions extrapolated from the deep-inelastic region, we also quantify the degree to which quark-hadron duality holds for $g_{1}$ and $g_{2}$ and their moments.
hep-phhep-exnucl-thPRC(2023)·12 citations
32*
Status of Electroweak Baryogenesis in Minimal Composite Higgs
Sebastian Bruggisser🇩🇪 · Benedict von Harling🇪🇸 · Oleksii Matsedonskyi🇬🇧 · Geraldine Servant🇩🇪
We present an update on the status of electroweak baryogenesis in minimal composite Higgs models. The particularity of this framework is that the electroweak phase transition can proceed simultaneously with the confinement phase transition of the new strong dynamics that produces the composite Higgs. The latter transition is controlled by the dilaton - the pseudo-Goldstone boson of an approximate scale invariance of the composite sector. Since it naturally is first-order, the electroweak phase transition becomes first-order too. Another appealing aspect is that the necessary additional source of CP violation can arise from the variation of the quark Yukawa couplings during the phase transition, which is built-in naturally in this scenario. These two features address the shortcomings of electroweak baryogenesis in the Standard Model. We confront this scenario with the latest experimental bounds derived from collider searches for new resonances and measurements of the Higgs couplings and electric dipole moments. All these constraints provide (or will be able to provide in the near future) important bounds on the considered scenario, with the most stringent ones coming from LHC searches for new resonances which constrain the dilaton mass and couplings. We identify the viable region of parameter space which satisfies all the constraints, and is characterized by a dilaton mass in the $300 - 500$ GeV range and a Higgs decay constant $f ≲ 1.1$ TeV. We discuss its future tests.
hep-phJHEP(2023)·31 citations
33*
pp elastic scattering at ISR and LHC energies
M. L. Nekrasov🇷🇺
We describe data on elastic $pp$ scattering at ISR and LHC energies using the analytical representation of the amplitude as the sum of three exponentials equipped with complex phases. In addition, we take into account the Coulomb and Coulomb-nuclear contributions in the entire transfer region and strong "perturbative" contributions in the large transfer region. Refined values of basic scattering characteristics are obtained. Significant changes in the behavior of the amplitude are detected at the transition from ISR to LHC energies. The results obtained indicate a two-layer structure of the colliding protons. In the transition to 13 TeV, a sharp increase in the size of the inner layer and its activity in the scattering is observed. A possible interpretation of this effect is discussed.
hep-phPRD(2023)·2 citations
34*
Primordial Black Holes as a Factory of Axions: Extragalactic Photons from Axions
Yongsoo Jho🇰🇷 · Tae-Geun Kim🇰🇷 · Jong-Chul Park🇰🇷 · Seong Chan Park🇰🇷 · Yeji Park🇰🇷
Primordial black holes (PBHs) are significant sources of axions and axion-like particles (ALPs), provided their Hawking temperature exceeds the particles' masses. Given the predominant decay of axions into photons, the enhanced photon spectrum they generate can be feasibly detected using sensitive detectors. This paper introduces a novel methodology that elucidates the decay process for particles to traverse and decay over cosmological timescales. Specifically, we derive estimations for the photon spectrum and flux, assuming a monochromatic mass spectrum and isotropic distribution for PBHs. Encouragingly, forthcoming detectors like e-ASTROGAM are well positioned to capture this signal.
hep-phastro-ph.HEPTEP(2026)·16 citations
35*
Detecting Axion-Like Particles with Primordial Black Holes
Kaustubh Agashe🇺🇸 · Jae Hyeok Chang🇺🇸 · Steven J. Clark🇺🇸 · Bhaskar Dutta🇺🇸 · Yuhsin Tsai🇺🇸 · Tao Xu🇺🇸
Future gamma-ray experiments, such as the e-ASTROGAM and AMEGO telescopes, can detect the Hawking radiation of photons from primordial black holes (PBHs) if they make up a fraction or all of dark matter. PBHs can analogously also Hawking radiate new particles, which is especially interesting if these particles are mostly secluded from the Standard Model (SM) sector, since they might therefore be less accessible otherwise. A well-motivated example of this type is axion-like particles (ALPs) with a tiny coupling to photons. We assume that the ALPs produced by PBHs decay into photons well before reaching the earth, so these will augment the photons directly radiated by the PBHs. Remarkably, we find that the peaks in the energy distributions of ALPs produced from PBHs are different than the corresponding ones for Hawking radiated photons due to the spin-dependent greybody factor. Therefore, we demonstrate that this process will in fact distinctively modify the PBHs' gamma-ray spectrum relative to the SM prediction. We use monochromatic asteroid-mass PBHs as an example to show that e-ASTROGAM can observe the PBH-produced ALP gamma-ray signal (for masses up to ~60 MeV) and further distinguish it from Hawking radiation without ALPs. By measuring the gamma-ray signals, e-ASTROGAM can thereby probe yet unexplored parameters in the ALP mass and photon coupling.
hep-phastro-ph.COastro-ph.GAPRD(2023)·28 citations
36*
Toward Exploring Phase Diagrams of Gauge Theories on Quantum Computers with Thermal Pure Quantum States
Zohreh Davoudi🇺🇸 · Niklas Mueller🇺🇸 · Connor Powers🇺🇸
Aiming at evading the notorious sign problem in classical Monte-Carlo approaches to lattice quantum chromodynamics, we present an approach for quantum computing finite-temperature lattice gauge theories at non-zero density. Based on the thermal pure-quantum-state formalism of statistical mechanics when extended to gauge-theory systems, our approach allows for sign-problem-free quantum computations of thermal expectation values and non-equal time correlation functions. By taking a simple lattice gauge theory for which classical benchmarks are possible, namely $Z_{2}$ lattice gauge theory in 1+1 dimensions at finite chemical potential, we discuss resource requirements and robustness to algorithmic and hardware imperfections for near-term quantum-hardware realizations.
↳ hep-lathep-phquant-phPoS(2023)·3 citations
37*
Probing a polymerized black hole with the frequency shifts of photons
Qi-Ming Fu🇺🇸 · Xin Zhang🇺🇸
As is well-known, black hole plays an important role in probing the quantum effects of gravity in the strong-field regime. In this paper, we focus on a polymerized black hole and investigate the quantum effects on the redshift, blueshift and gravitational redshift of photons emitted by massive particles revolving around this black hole. With a general relativistic formalism, we obtain two elegant and concise expressions for the mass of the black hole and the quantum parameter in terms of few direct observables, and find that all the frequency shifts of photons decrease with the quantum parameter. By expanding the total frequency shift for large orbit of the emitter, low peculiar redshift, and small azimuthal angle, we find that the leading contributions to the frequency shift are originated from the kinematic shift and peculiar shift, and the quantum effects make a negligible contribution. In addition, we study the effects of the plasma on the redshift/blueshift for the first time, and conclude that the presence of plasma results in the decrease of the redshift/blueshift.
↳ gr-qchep-phPRD(2023)·12 citations
38*
Photon production rate from Transverse-Longitudinal ( $T - L$ ) mesonic correlator on the lattice
Dibyendu Bala🇩🇪 · Sajid Ali🇩🇪 · Anthony Francis🇹🇼 · Greg Jackson🇺🇸 · Olaf Kaczmarek🇩🇪 · Tristan Ueding🇩🇪
Thermal photons from the QGP provide important information about the interaction among plasma constituents. The photon production rate from a thermally equilibrated system is proportional to the transverse spectral function $ρ_{T} (ω = ∣ k ∣, k)$ . One can also calculate the photon production rate from the difference between $ρ_{T} (ω, k)$ (transverse) and $ρ_{L} (ω, k)$ (longitudinal) projections, as $ρ_{L}$ vanishes on the photon point. Because the UV part of $ρ_{T} - ρ_{L}$ is suppressed, the corresponding Euclidean correlator receives most of its contribution from the IR part. We calculate the $T - L$ correlator on $N_{f} = 2 + 1$ flavour HISQ configurations with $m_{l} = m_{s} /5$ at temperature of about $1.15 T_{p c}$ (220 MeV). We have used two ansätze for the spectral function: 1) A polynomial connected to the UV region consistent with OPE expansion and 2) a hydro-inspired spectral function. We have also applied the Backus-Gilbert method to estimate the spectral function. All these different approaches are combined to estimate the photon production rate.
↳ hep-lathep-phPoS(2023)·4 citations
39*
Proposal for the search for exotic spin-spin interactions at the micrometer scale using functionalized cantilever force sensors
Qian Wang🇨🇳 · Ze Ouyang🇨🇳 · Yu Lu🇨🇳 · Jianbo Wang🇨🇳 · Lin Zhu🇨🇳 · Pengshun Luo🇨🇳
Spin-dependent exotic interactions can be generated by exchanging hypothetical bosons, which were introduced to solve some puzzles in physics. Many precision experiments have been performed to search for such interactions, but no confirmed observation has been made. Here, we propose new experiments to search for the exotic spin-spin interactions that can be mediated by axions or Z $^{'}$ bosons. A sensitive functionalized cantilever is utilized as a force sensor to measure the interactions between the spin-polarized electrons in a periodic magnetic source structure and a closed-loop magnetic structure integrated on the cantilever. The source is set to oscillate during data acquisition to modulate the exotic force signal to high harmonics of the oscillating frequency. This helps to suppress the spurious signals at the signal frequency. Different magnetic source structures are designed for different interaction detections. A magnetic stripe structure is designed for Z $^{'}$ -mediated interaction, which is insensitive to the detection of axion-mediated interaction. This allows us to measure the coupling constant of both if we assume both exist. With the force sensitivity achievable at low temperature, the proposed experiments are expected to search for the parameter spaces with much smaller coupling constant than the current stringent constraints from micrometer to millimeter range. Specifically, the lower bound of the parameter space will be seven orders of magnitude lower than the stringent constraints for Z $^{'}$ -mediated interaction, and an order of magnitude lower for axion-mediated interaction, at the interaction range of $10 μ$ m.
↳ hep-exhep-phPRD(2023)·7 citations
40*
Smallest drop of QGP: Thermodynamic properties in p-Pb collisions
Fernando G. Gardim🇧🇷 · Renata Krupczak🇧🇷 · Tiago Nunes da Silva🇧🇷
The extreme conditions of temperature and density produced in ultrarelativistic collisions of heavy nuclei facilitate the formation of the most fundamental fluid in the universe, the deconfined phase of Quantum Chromodynamics called quark-gluon plasma. Despite the extensive experimental evidence collected over the past decade of its production in colliding systems such as Au-Au and Pb-Pb, establishing quark-gluon plasma formation in the collision of smaller systems, such as p-Pb, remains an open question. In this study, we describe the evolution of matter formed in p-Pb collisions at 5.02 TeV using a state-of-the-art hybrid model based on viscous relativistic hydrodynamics. We investigate the thermodynamic properties of the medium and final state observables. Our findings are compared with experimental data and first-principles calculations derived from lattice quantum chromodynamics. The results support the formation of a collective phase of strongly interacting matter in high-multiplicity p-Pb collisions.
↳ nucl-thhep-phPRC(2024)·14 citations
41*
A new bound on the electron's electric dipole moment
Tanya S. Roussy🇺🇸 · Luke Caldwell🇺🇸 · Trevor Wright🇺🇸 · William B. Cairncross🇺🇸 · Yuval Shagam🇺🇸 · Kia Boon Ng🇺🇸 · Noah Schlossberger🇺🇸 · Sun Yool Park🇺🇸 · Anzhou Wang🇨🇳 · Jun Ye🇺🇸 · Eric A. Cornell🇺🇸
The Standard Model cannot explain the dominance of matter over anti-matter in our universe. This imbalance indicates undiscovered physics that violates combined CP symmetry. Many extensions to the Standard Model seek to explain the imbalance by predicting the existence of new particles. Vacuum fluctuations of the fields associated with these new particles can interact with known particles and make small modifications to their properties; for example, particles which violate CP symmetry will induce an electric dipole moment of the electron (eEDM). The size of the induced eEDM is dependent on the masses of the new particles and their coupling to the Standard Model. To date, no eEDM has been detected, but increasingly precise measurements probe new physics with higher masses and weaker couplings. Here we present the most precise measurement yet of the eEDM using electrons confined inside molecular ions, subjected to a huge intra-molecular electric field, and evolving coherently for up to 3 s. Our result is consistent with zero and improves on the previous best upper bound by a factor $\sim 2.4$ . Our sensitivity to $1 0^{- 19}$ eV shifts in molecular ions provides constraints on broad classes of new physics above $1 0^{13}$ eV, well beyond the direct reach of the LHC or any other near- or medium-term particle collider.
↳ physics.atom-phhep-exhep-phScience(2023)·397 citations
42*
Beyond (and back to) Palatini quadratic gravity and inflation
Christian Dioguardi🇪🇪 · Antonio Racioppi🇪🇪 · Eemeli Tomberg🇪🇪
We study single-field slow-roll inflation embedded in Palatini $F (R)$ gravity where $F (R)$ grows faster than $R^{2}$ . Surprisingly, the consistency of the theory requires the Jordan frame inflaton potential to be unbounded from below. Even more surprisingly, this corresponds to an Einstein frame inflaton potential bounded from below and positive definite. We prove that for all such Palatini $F (R)$ 's, there exists a universal strong coupling limit corresponding to a quadratic $F (R)$ with the wrong sign for the linear term and a cosmological constant in the Jordan frame. In such a limit, the tensor-to-scalar ratio $r$ does not depend on the original inflaton potential, while the scalar spectral index $n_{s}$ does. Unfortunately, the system is ill-defined out of the slow-roll regime. A possible way out is to upgrade to a $F (R, X)$ model, with $X$ the Jordan frame inflaton kinetic term. Such a modification essentially leaves the inflationary predictions unaffected.
↳ gr-qcastro-ph.COhep-phJCAP(2024)·21 citations
43*
A novel model-marginalized cosmological bound on the QCD axion mass
Eleonora Di Valentino🇬🇧 · Stefano Gariazzo🇮🇹 · William Giarè🇮🇹 · Alessandro Melchiorri🇮🇹 · Olga Mena🇪🇸 · Fabrizio Renzi🇳🇱
We present model-marginalized limits on mixed hot dark matter scenarios, which consider both thermal neutrinos and thermal QCD axions. A novel aspect of our analyses is the inclusion of small-scale Cosmic Microwave Background (CMB) observations from the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT), together with those from the Planck satellite and Baryon Acoustic Oscillation (BAO) data. After marginalizing over a number of well-motivated non-minimal background cosmologies, the tightest $95%$ CL upper bound we obtain is $0.21$ eV, both for $\sum m_{ν}$ and $m_{a}$ , from the combination of ACT, Planck and BAO measurements. Restricting the analyses to the standard $Λ$ CDM picture, we find $\sum m_{ν} < 0.16$ eV and $m_{a} < 0.18$ eV, both at $95%$ CL. Interestingly, the best background cosmology is never found within the minimal $Λ$ CDM plus hot relics, regardless of the data sets exploited in the analyses. The combination of Planck with either BAO, SPT or ACT prefers a universe with a non-zero value of the running in the primordial power spectrum with strong evidence. Small-scale CMB probes, both alone and combined with BAO, either prefer, with substantial evidence, non-flat universes (as in the case of SPT) or a model with a time varying dark energy component (as in the case of ACT).
↳ astro-ph.COhep-phPRD(2023)·18 citations
44*
Self-Interacting Gravitational Atoms in the Strong-Gravity Regime
Horng Sheng Chia🇺🇸 · Christoffel Doorman🇬🇧 · Alexandra Wernersson🇳🇱 · Tanja Hinderer🇳🇱 · Samaya Nissanke🇳🇱
We numerically investigate free and self-interacting ultralight scalar fields around black holes in General Relativity. We focus on complex scalar fields $Φ$ whose self-interactions are described by the quartic potential $V \propto λ ∣Φ ∣^{4}$ , and ignore the black hole spin in order to disentangle the effects of self interactions on the boson cloud. Using the spectral solver Kadath, we compute quasi-equilibrium configurations of the dominant eigenstates, including their backreaction on the spacetime metric. For scenarios with $- 1 0^{- 2} ≲ λ ≲ 1 0^{- 2}$ we find the mass of the self-interacting scalar cloud to be up to $\sim 70%$ larger than that of a free scalar cloud, though the additional backreaction effect on the spacetime metric is only up to $\sim 1%$ due to the low-density nature of the bosonic configurations. In this region of parameter space we observe approximate quadratic scalings between the mass of the cloud with $λ$ , the scalar field amplitude, and the couplings between these two parameters. For systems with $λ$ beyond this range, the eigenfrequencies differ sufficiently from the known free-test-field values used as inputs in our numerical setup to make the results, though convergent, physically unreliable. This bounds the range of $λ$ in which the free scalar field solution remains a good approximation to self-interacting scalar field configurations. Our work is among the first nonperturbative explorations of self-interacting bosonic clouds around black holes, yielding detailed new insights into such systems in the nonlinear regime, while also overcoming technical challenges and quantifying limitations. Additionally, our results provide useful inputs for fully dynamical numerical relativity simulations and for future explorations of spinning black holes and real scalar fields.
↳ gr-qchep-phhep-thJCAP(2023)·26 citations
45*
Gravitational wave lensing as a probe of halo properties and dark matter
Giovanni Tambalo🇩🇪 · Miguel Zumalacárregui🇩🇪 · Liang Dai🇺🇸 · Mark Ho-Yeuk Cheung🇺🇸
Just like light, gravitational waves (GWs) are deflected and magnified by gravitational fields as they propagate through the Universe. However, their low frequency, phase coherence and feeble coupling to matter allow for distinct lensing phenomena, such as diffraction and central images, that are challenging to observe through electromagnetic sources. Here we explore how these phenomena can be used to probe features of gravitational lenses. We focus on two variants of the singular isothermal sphere, with 1) a variable slope of the matter density and 2) a central core. We describe the imprints of these features in the wave- and geometric-optics regimes, including the prospect of detecting central images. We forecast the capacity of LISA and advanced LIGO to study strongly lensed signals and measure the projected lens mass, impact parameter and slope or core size. A broad range of lens masses allows all parameters to be measured with precision up to $\sim 1/ SNR$ , despite large degeneracies. Thanks to wave-optics corrections, all parameters can be measured, even when no central image forms. Although GWs are sensitive to projected quantities, we compute the probability distribution of lens redshift, virial mass and projection scale given a cosmology. As an application, we consider the prospect of constraining self-interacting and ultra-light dark matter, showing the regions of parameter space accessible to strongly-lensed GWs. The distinct GW signatures will enable novel probes of fundamental physics and astrophysics, including the properties of dark matter and the central regions of galactic halos.
↳ astro-ph.COgr-qchep-phPRD(2023)·100 citations
46*
(Semi)leptonic kaon decays and neutral kaon mixing from lattice QCD
Takashi Kaneko🇯🇵
We review recent progress on leptonic and semileptonic kaon decays and neutral kaon mixing from lattice QCD.
↳ hep-lathep-phJ.Phys.Conf.Ser.(2023)·1 citation

* 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.