Thu·May 25, 2023Thursday·May 25, 2023

1. 01*

   A New Window into Gravitationally Produced Scalar Dark Matter

   Marcos A. G. Garcia🇲🇽 · Mathias Pierre🇩🇪 · Sarunas Verner🇺🇸

   Conventional scenarios of purely gravitationally produced dark matter with masses below the Hubble parameter at the end of inflation are in tension with Cosmic Microwave Background (CMB) constraints on the isocurvature power spectrum. We explore a more general scenario with a non-minimal coupling between the scalar dark matter field and gravity, which allows for significantly lighter scalar dark matter masses compared to minimal coupling predictions. By imposing relic abundance, isocurvature, Lyman-$\alpha$, and Big Bang Nucleosynthesis (BBN) constraints, we show the viable parameter space for these models. Our findings demonstrate that the presence of a non-minimal coupling expands the parameter space, yielding a dark matter mass lower bound of $2\times 10^{-4}\mathrm{eV}$.

   hep-phastro-ph.COgr-qcPRD(2023)·47 citations
2. 02*

   The case for an EIC Theory Alliance: Theoretical Challenges of the EIC

   Raktim Abir · Igor Akushevich · Tolga Altinoluk · Daniele Paolo Anderle · Fatma P. Aslan · Alessandro Bacchetta · Baha Balantekin · Joao Barata · Marco Battaglieri · Carlos A. Bertulani · Guillaume Beuf · Chiara Bissolotti and 159 other authors

   We outline the physics opportunities provided by the Electron Ion Collider (EIC). These include the study of the parton structure of the nucleon and nuclei, the onset of gluon saturation, the production of jets and heavy flavor, hadron spectroscopy and tests of fundamental symmetries. We review the present status and future challenges in EIC theory that have to be addressed in order to realize this ambitious and impactful physics program, including how to engage a diverse and inclusive workforce. In order to address these many-fold challenges, we propose a coordinated effort involving theory groups with differing expertise is needed. We discuss the scientific goals and scope of such an EIC Theory Alliance.

   hep-phhep-ex116 citations
3. 03*

   Automated calculation of Jet fragmentation at NLO in QCD

   ChongYang Liu🇨🇳 · XiaoMin Shen🇨🇳 · Bin Zhou🇨🇳 · Jun Gao🇨🇳

   We present FMNLO, a framework to combine general-purpose Monte Carlo generators and fragmentation functions (FFs). It is based on a hybrid scheme of phase-space slicing method and local subtraction method, and accurate to next-to-leading order (NLO) in QCD. The new framework has been interfaced to MG5 aMC@NLO and made publicly available in this work. We demonstrate its unique ability by giving theoretical predictions of various fragmentation measurements at the LHC, followed by comparison with the data. With the help of interpolation techniques, FMNLO allows for fast calculation of fragmentation processes for a large number of different FFs, which makes it a promising tool for future fits of FFs. As an example, we perform a NLO fit of parton fragmentation functions to unidentified charged hadrons using measurements at the LHC. We find the ATLAS data from inclusive dijet production show a strong constraining power. Notable disparities are found between our gluon FF and that of BKK, DSS and NNFF, indicating the necessities of additional constraints and data for gluon fragmentation function.

   hep-phhep-exnucl-thJHEP(2023)·23 citations
4. 04*

   Two-pole structure of the $b_1$(1235) axial-vector meson

   Samson Clymton🇰🇷 · Hyun-Chul Kim🇰🇷

   We investigate the dynamical generation of the $b_1$ meson in the $\pi \omega$ interaction, using the fully off-mass-shell coupled-channel formalism with the $\pi \omega$, $\eta \rho$, $\pi \varphi$, and $K{\bar{K}}^{\ast }$ channels included. We first construct the Feynman amplitudes for the sixteen different kernel amplitudes, considering only the $t$ and $u$ channels. Solving the coupled integral equation, we obtain the transition amplitude for the $\pi \omega$ interaction. We select the axial-vector and isovector channels from the partial-wave expansion and single out the two poles corresponding to the $b_1$ mesons: $(1306-i70)$ MeV and $(1356-i65)$ MeV. They are located below the $K{\bar{K}}^{\ast }$ threshold. The first pole lies below the $\eta \rho$ threshold by about 10 MeV, whereas the second one emerges above it by about 40 MeV. We analyze the effects of the two poles and background contributions to the $\pi \omega$ total cross section by using a toy model.

   hep-phhep-exPRD(2023)·10 citations
5. 05*

   Global analysis of measured and unmeasured hadronic two-body weak decays of antitriplet charmed baryons

   Zhi-Peng Xing🇨🇳 · Xiao-Gang He🇨🇳 · Fei Huang🇨🇳 · Chang Yang🇨🇳

   A large amount of data on hadronic two body weak decays of anti-triplet charmed baryons $T_{c\bar{3}}$ to an octet baryon $T_8$ and an octet or singlet pseudoscalar meson $P$, $T_{c\bar{3}}\to T_{8}P$, have been measured. The SU(3) flavor symmetry has been applied to study these decays to obtain insights about weak interactions for charm physics. However not all such decays needed to determine the SU(3) irreducible amplitudes have been measured forbidding a complete global analysis. Previously, it has been shown that data from measured decays can be used to do a global fit to determine all except one parity violating and one parity conserving amplitudes of the relevant SU(3) irreducible amplitudes causing 8 hadronic two body weak decay channels involving ${\Xi }_c^0$ to $\eta$ or ${\eta }^{\prime }$ transitions undetermined. It is important to obtain information about these decays in order to guide experimental searches. In this work using newly measured decay modes by BESIII and Belle in 2022, we carry out a global analysis and parameterize the unknown amplitudes to provide the ranges for the branching ratios of the 8 undetermined decays. Our results indicate that the SU(3) flavor symmetry can explain the measured data exceptionally well, with a remarkable minimal ${\chi }^2/d.o.f.$ of 1.21 and predict 80 observables in 45 decays for future experimental data to test. We then vary the unknown SU(3) amplitudes to obtain the allowed range of branching ratios for the 8 undetermined decays. We find that some of them are within reach of near future experimental capabilities. We urge our experimental colleagues to carry out related searches.

   hep-phPRD(2023)·31 citations
6. 06*

   Structure of the medium formed in heavy ion collisions

   J. R. Alvarado García🇲🇽 · D. Rosales Herrera🇲🇽 · A. Fernández Téllez🇲🇽 · Bogar Díaz🇪🇸 · J. E. Ramírez🇲🇽

   We investigate the structure of the medium formed in heavy ion collisions using three different models: the Color String Percolation Model (CSPM), the Core-Shell-Color String Percolation Model (CSCSPM), and the Color Glass Condensate (CGC) framework. We analyze the radial distribution function of the transverse representation of color flux tubes in each model to determine the medium's structure. Our results indicate that the CSPM behaves as an ideal gas, while the CSCSPM exhibits a structural phase transition from a gas-like to a liquid-like structure. Additionally, our analysis of the CGC framework suggests that it produces systems that behave like interacting gases for AuAu central collisions at RHIC energies and liquid-like structures for PbPb central collisions at LHC energies.

   hep-phnucl-thUniverse(2023)·1 citation
7. 07*

   Study of anomalous $W^{-}{W}^{+}\gamma /Z$ couplings using polarizations and spin correlations in $e^{-}{e}^{+}\to W^{-}{W}^{+}$ with polarized beams

   Amir Subba🇮🇳 · Ritesh K. Singh🇮🇳

   We study the anomalous $W^{-}{W}^{+}\gamma /Z$ couplings in $e^{-}{e}^{+}\to W^{-}{W}^{+}$ followed by semileptonic decay using a complete set of polarization and spin correlation observables of $W$ boson with the longitudinally polarized beam. We consider a complete set of dimension-six operators affecting $W^{-}{W}^{+}\gamma /Z$ vertex, which are $SU(2)\times U(1)$ gauge invariant. Some of the polarization and spin correlation asymmetries average out if the daughter of $W^{+}$ is not tagged. We developed an artificial neural network and boosted decision trees to distinguish down-type jets from up-type jets. We obtain bounds on the anomalous couplings for center of mass energy $\sqrt{s}=250$ GeV with integrated luminosities of~$\mathcal{L}\in \{100{\text{fb}}^{-1},250{\text{fb}}^{-1},1000{\text{fb}}^{-1},3000{\text{fb}}^{-1}\}$. We find that using spin-related observables and cross~section in the presence of initial beam polarization significantly improves the bounds on anomalous couplings compared to previous studies.

   hep-phEPJC(2023)·7 citations
8. 08*

   Bilinear R-parity violating supersymmetry under the light of neutrino oscillation, higgs and flavor data

   Arghya Choudhury🇮🇳 · Sourav Mitra🇮🇳 · Arpita Mondal🇮🇳 · Subhadeep Mondal🇮🇳

   In this work, we explore a well motivated beyond the Standard Model scenario, namely, R-parity violating Supersymmetry, in the context of light neutrino masses and mixing. We assume that the R-parity is only broken by the lepton number violating bilinear term. We try to fit two non-zero neutrino mass square differences and three mixing angle values obtained from the global ${\chi }^2$ analysis of neutrino oscillation data. We have also taken into account the updated data of the standard model (SM) Higgs mass and its coupling strengths with other SM particles from LHC Run-II along with low energy flavor violating constraints like rare b-hadron decays. We have used a Markov Chain Monte Carlo (MCMC) analysis to constrain the new physics parameter space. While doing so, we ensure that all the existing collider constraints are duly taken into account. Through our analysis, we have derived the most stringent constraints possible to date with existing data on the 9 bilinear R-parity violating parameters along with $\mu$ and $\tan \beta$. We further explore the possibility of explaining the anomalous muon~(g~-~2) measurement staying within the parameter space allowed by neutrino, Higgs and flavor data while satisfying the collider constraints as well. We find that there still remains a small sub-TeV parameter space where the required excess can be obtained.

   hep-phhep-exJHEP(2024)·16 citations
9. 09*

   Production of Excited Doubly Heavy Baryons at the Super-$Z$ Factory

   Juan-Juan Niu🇨🇳 · Jing-Bo Li🇨🇳 · Huan-Yu Bi🇨🇳 · Hong-Hao Ma🇨🇳

   In the framework of nonrelativistic QCD, the excited doubly heavy baryons are thoroughly studied via the channel $e^{+}{e}^{-}\to ⟨Q{Q}^{\prime }⟩[n]\to {\Xi }_{Q{Q}^{\prime }}+\overline{Q^{\prime }}+\bar{Q}$, which takes place at the collision energy $Z$-pole. $Q^{(\prime )}$ represents $b$ or $c$ quark for the production of ${\Xi }_{cc}$, ${\Xi }_{bc}$, and ${\Xi }_{bb}$, respectively. All of the intermediate diquark states $⟨Q{Q}^{\prime }⟩[n]$ in $P$-wave, $⟨cc⟩{[}^1{P}_1{]}_{\bar{3}}$, $⟨cc⟩{[}^3{P}_J{]}_6$, $⟨bc⟩{[}^1{P}_1{]}_{\bar{3}/6}$, $⟨bc⟩{[}^3{P}_J{]}_{\bar{3}/6}$, $⟨bb⟩{[}^1{P}_1{]}_{\bar{3}}$, and $⟨bb⟩{[}^3{P}_J{]}_6$ with $J=0$, 1, or 2, are taken into account. The cross sections and differential distributions, including the transverse momentum, rapidity, angular, and invariant mass, are discussed for the excited baryons production. We find that the contributions of $⟨cc⟩$, $⟨bc⟩$, and $⟨bb⟩$ in $P$-wave are found to be 3.97$\%$, 5.08$\%$, and 5.89$\%$, respectively, compared to $S$-wave. Supposing that all excited states can decay into the ground state 100\%, the total events $N_{{\Xi }_{cc}}=8.48\times 10^{4-6}$, $N_{{\Xi }_{bc}}=2.26\times 10^{5-7}$, and $N_{{\Xi }_{bb}}=4.12\times 10^{3-5}$ would be produced at the Super-$Z$ Factory with a high luminosity up to $\mathcal{L}\simeq 10^{34-36}{\mathrm{cm}}^{-2}{\mathrm{s}}^{-1}$.

   hep-phEPJC(2023)·9 citations
10. 10*

    Extraction of the Parton Momentum-Fraction Dependence of Generalized Parton Distributions from Exclusive Photoproduction

    Jian-Wei Qiu🇺🇸 · Zhite Yu🇺🇸

    The $x$ dependence of hadrons' generalized parton distributions (GPDs) $\mathcal{F}(x,\xi ,t)$ is the most difficult to extract from the existing known processes, while the $\xi$ and $t$ dependence are uniquely determined by the kinematics of the scattered hadron. We study the single diffractive hard exclusive processes for extracting GPDs in the photoproduction. We demonstrate quantitatively the enhanced sensitivity on extracting the $x$ dependence of various GPDs from the photoproduction cross sections, as well as the asymmetries constructed from photon polarization and hadron spin that could be measured at JLab Hall D by GlueX Collaboration and future facilities.

    hep-phhep-exhep-latnucl-ex+1PRL(2023)·42 citations
11. 11*

    Discriminating $B\to D^{\ast }\ell \nu$ form factors via polarization observables and asymmetries

    Marco Fedele🇩🇪 · Monika Blanke🇩🇪 · Andreas Crivellin🇨🇭 · Syuhei Iguro🇩🇪 · Ulrich Nierste🇩🇪 · Silvano Simula🇮🇹 · Ludovico Vittorio🇫🇷

    Form factors are crucial theory input in order to extract $|V_{cb}|$ from $B\to D^{(\ast )}\ell \nu$ decays, to calculate the Standard Model prediction for $\mathcal{R}(D^{(\ast )})$ and to assess the impact of New Physics. In this context, the Dispersive Matrix approach, a first-principle calculation of the form factors, using no experimental data but rather only lattice QCD results as input, was recently applied to $B\to D^{(\ast )}\ell \nu$. It predicts (within the Standard Model) a much milder tension with the $\mathcal{R}(D^{\ast })$ measurements than the other form factor approaches, while at the same time giving a value of $|V_{cb}|$ compatible with the inclusive value. However, this comes at the expense of creating tensions with differential $B\to D^{\ast }\ell \nu$ distributions (with light leptons). In this article, we explore the implications of using the Dispersive Matrix method form factors, in light of the recent Belle (II) measurements of the longitudinal polarization fraction of the $D^{\ast }$ in $B\to D^{\ast }\ell \nu$ with light leptons, $F_L^{\ell }$, and the forward-backward asymmetry, $A_{\mathrm{FB}}^{\ell }$. We find that the Dispersive Matrix approach predicts a Standard Model value of $F_L^{\ell }$ that is in significant tension with these measurements, while mild deviations in $A_{\mathrm{FB}}^{\ell }$ appear. Furthermore, $F_L^{\ell }$ is very insensitive to New Physics such that the latter cannot account for the tension between Dispersive Matrix predictions and its measurement. While this tension can be resolved by deforming the original Dispersive Matrix form factor shapes within a global fit, a tension in $\mathcal{R}(D^{\ast })$ reemerges. As this tension is milder than for the other form factors, it can be explained by New Physics not only in the tau lepton channel but also in the light lepton modes.

    hep-phhep-exhep-latPRD(2023)·40 citations
12. 12*

    Transverse Momentum Distributions of Heavy Hadrons and Polarized Heavy Quarks

    Rebecca von Kuk🇩🇪 · Johannes K. L. Michel🇺🇸 · Zhiquan Sun🇺🇸

    We initiate the study of transverse momentum-dependent (TMD) fragmentation functions for heavy quarks, demonstrate their factorization in terms of novel nonperturbative matrix elements in heavy-quark effective theory (HQET), and prove new TMD sum rules that arise from heavy-quark spin symmetry. We discuss the phenomenology of heavy-quark TMD FFs at $B$ factories and find that the Collins effect, in contrast to claims in the literature, is not parametrically suppressed by the heavy-quark mass. We further calculate all TMD parton distribution functions for the production of heavy quarks from polarized gluons within the nucleon and use our results to demonstrate the potential of the future EIC to resolve TMD heavy-quark fragmentation in semi-inclusive DIS, complementing the planned EIC program to use heavy quarks as probes of gluon distributions.

    hep-phJHEP(2023)·27 citations
13. 13*

    The QCD axion sum rule

    Belén Gavela🇪🇸 · Pablo Quílez🇺🇸 · Maria Ramos🇪🇸

    We demonstrate that the true QCD axion that solves the strong CP problem can be found in all generality outside the customary standard QCD band, with QCD being the sole source of Peccei-Quinn breaking. The essential reason is that the basis of axion-gluon interactions does not need to coincide with the mass basis. Specifically, we consider the case in which the QCD axion field is not the only singlet scalar in Nature but it mixes with other singlet scalars (besides the ${\eta }^{\prime }$). We determine the exact mathematical condition for an arbitrary $N$-scalar potential to be Peccei-Quinn invariant. Such potentials provide extra sources of mass for the customary axion without enlarging the Standard Model gauge symmetry. The contribution to the axion mass stemming from the QCD topological susceptibility is shown to be shared then among the $N$ axion eigenstates through a precise sum rule. Their location can only be displaced to the right of the standard QCD band. We demonstrate that the axion closest to this band can be displaced from it by a factor of $\sqrt{N}$ at most, and this corresponds to the case in which all axion signals are maximally deviated. Conversely, if one axion is found on the standard QCD band, the other eigenstates will be out of experimental reach. Our results imply that any ALP experiment which finds a signal outside the standard QCD axion band can be solving the strong CP problem within QCD, with the associated $N-1$ excitations to be found in an area of parameter space that we determine. We illustrate the results and phenomenology in some particular cases.

    hep-phhep-thJHEP(2024)·43 citations
14. 14*

    AutoSourceID-FeatureExtractor. Optical image analysis using a two-step mean variance estimation network for feature estimation and uncertainty characterisation

    F. Stoppa · R. Ruiz de Austri🇪🇸 · P. Vreeswijk · S. Bhattacharyya🇮🇳 · S. Caron🇳🇱 · S. Bloemen · G. Zaharijas🇸🇮 · G. Principe🇮🇹 · V. Vodeb🇸🇮 · P.J. Groot · E. Cator · G. Nelemans

    Aims. In astronomy, machine learning has been successful in various tasks such as source localisation, classification, anomaly detection, and segmentation. However, feature regression remains an area with room for improvement. We aim to design a network that can accurately estimate sources' features and their uncertainties from single-band image cutouts, given the approximated locations of the sources provided by the previously developed code AutoSourceID-Light (ASID-L) or other external catalogues. This work serves as a proof of concept, showing the potential of machine learning in estimating astronomical features when trained on meticulously crafted synthetic images and subsequently applied to real astronomical data. Methods. The algorithm presented here, AutoSourceID-FeatureExtractor (ASID-FE), uses single-band cutouts of 32x32 pixels around the localised sources to estimate flux, sub-pixel centre coordinates, and their uncertainties. ASID-FE employs a two-step mean variance estimation (TS-MVE) approach to first estimate the features and then their uncertainties without the need for additional information, for example the point spread function (PSF). For this proof of concept, we generated a synthetic dataset comprising only point sources directly derived from real images, ensuring a controlled yet authentic testing environment. Results.We show that ASID-FE, trained on synthetic images derived from the MeerLICHT telescope, can predict more accurate features with respect to similar codes such as SourceExtractor and that the two-step method can estimate well-calibrated uncertainties that are better behaved compared to similar methods that use deep ensembles of simple MVE networks. Finally, we evaluate the model on real images from the MeerLICHT telescope and the Zwicky Transient Facility (ZTF) to test its transfer learning abilities.

    ↳ astro-ph.IMhep-phAstron.Astrophys.(2023)·3 citations
15. 15*

    Imprints of Einstein-Maxwell dilaton-axion gravity in the observed shadows of Sgr A* and M87*

    Siddharth Kumar Sahoo🇮🇳 · Neeraj Yadav🇮🇳 · Indrani Banerjee🇮🇳

    Einstein-Maxwell dilaton-axion (EMDA) gravity provides a simple framework to investigate the signatures of string theory. The axion and the dilaton fields arising in EMDA gravity have important implications in inflationary cosmology and in addressing the late time acceleration of the universe. It is therefore instructive to explore the implications of such a model in explaining the astrophysical observations. In this work we explore the role of EMDA gravity in explaining the observed shadows of black holes (M87* and Sgr A*) released by the Event Horizon Telescope (EHT) collaboration. The Kerr-Sen metric represents the exact, stationary and axisymmetric black hole solution of EMDA gravity. Such a black hole is characterized by the angular momentum $a$ acquired from the axionic field and the dilatonic charge $r_2$ arising from string compactifications. We study the role of spin and the dilaton charge in modifying the shape and size of the black hole shadow. We note that black holes with larger dilaton charge cast a smaller shadow. We investigate the consequences of such a result in addressing the EHT observations of M87* and Sgr A*. Our analysis reveals that the shadow of M87* exhibits a preference towards the Kerr scenario. However, when 10% offset in the shadow diameter is considered, $0.1\lesssim r_2\lesssim 0.3$ is observationally favored within 1-$\sigma$. The shadow of Sgr A* on the other hand shows a preference towards the Kerr-Sen scenario since the central value of its shadow can be better explained by a non-zero dilaton charge $0.1\lesssim r_2\lesssim 0.4$. However, when the 1-$\sigma$ interval is considered the Kerr scenario is included. We discuss the implications of our results.

    ↳ gr-qcastro-ph.HEhep-phPRD(2024)·30 citations
16. 16*

    Implications of the Conformal Constraint on Sound Speed on the Radius of PSR J0952-0607 within Rastall Gravity

    Waleed El Hanafy🇪🇬 · Adel Awad🇪🇬

    It has been shown that the nonminimal coupling between geometry and matter can provide models for massive compact stars that are consistent with the conformal bound on the sound speed, $0⩽c_s^2⩽c^2/3$, where the core density approaches a few times the nuclear saturation density. We impose the conformal upper bound on the sound speed on Rastall's field equations of gravity, with Krori-Barua potentials in the presence of an anisotropic fluid as a matter source, to estimate the radius of the most massive pulsar ever observed, PSR J0952-0607. For its measured mass $M=2.35\pm 0.17M_{\odot }$, we obtain a radius $R=14.087\pm 1.0186$ km as inferred by the model. We investigate a possible connection between Rastall gravity and the MIT bag model with an equation of state, $p_r(\rho )\approx c_s^2\left(\rho -{\rho }_{\mathrm{s}}\right)$, in the radial direction, with $c_s=c/\sqrt{3}$ and a surface density ${\rho }_{\text{s}}$ slightly above the nuclear saturation density ${\rho }_{\text{nuc}}=2.7\times 10^{14}$ g/cm${}^3$. The corresponding mass-radius diagram is in agreement with our estimated value of the radius and with astrophysical observations of other pulsars at 68% confidence level.

    ↳ astro-ph.HEgr-qchep-phApJ·28 citations
17. 17*

    Ab initio study of nuclear clustering in hot dilute nuclear matter

    Zhengxue Ren🇩🇪 · Serdar Elhatisari🇹🇷 · Timo A. Lähde🇩🇪 · Dean Lee🇺🇸 · Ulf-G. Meißner🇩🇪

    We present a systematic ab initio study of clustering in hot dilute nuclear matter using nuclear lattice effective field theory with an SU(4)-symmetric interaction. We introduce a method called light-cluster distillation to determine the abundances of dimers, trimers, and alpha clusters as a function of density and temperature. Our lattice results are compared with an ideal gas model composed of free nucleons and clusters. Excellent agreement is found at very low density, while deviations from ideal gas abundances appear at increasing density due to cluster-nucleon and cluster-cluster interactions. In addition to determining the composition of hot dilute nuclear matter as a function of density and temperature, the lattice calculations also serve as benchmarks for virial expansion calculations, statistical models, and transport models of fragmentation and clustering in nucleus-nucleus collisions.

    ↳ nucl-thhep-phnucl-exPLB(2024)·37 citations
18. 18*

    Distinguishing the nanohertz gravitational-wave sources by the observations of compact dark matter subhalos

    Jing Liu🇨🇳

    The latest pulsar timing array data reveals evidence of nanohertz gravitational waves (GWs), which have been explained by both cosmological and astrophysical sources. However, current observations lack the precision needed to differentiate between different models from the spectral index. We find that the cosmological GW sources, including bubble collisions, sound waves, domain walls, condensate fragmentations, and primordial curvature perturbations, induce large energy density perturbations so that most dark matter will exist in gravitationally self-bound subhalos. Then, the observation of such substructures of dark matter can serve as a novel independent method to confirm or exclude the cosmological GW sources.

    ↳ astro-ph.COgr-qchep-phPRD(2023)·14 citations
19. 19*

    Weak decays of heavy-quark baryons

    Janina Nicolini (On behalf of the LHCb collaboration)🇩🇪

    Weak decays of heavy-quark baryons offer an attractive laboratory to search for effects beyond the Standard Model (SM), complementary to searches in meson decays. However, the properties of these baryons are not well understood. In particular, the ${\Omega }_b^{-}$ baryon is the least studied weakly decaying $b$ baryon. Therefore, the most precise determination of the ${\Omega }_b^{-}$ baryon mass is reported, using ${\Omega }_b^{-}\to J/\psi {\Omega }^{-}$ decays at the LHCb experiment. In addition, the relative production rate of the ${\Omega }_b^{-}$ baryon in $pp$ collisions at the LHC is determined for the first time. These quantities are crucial to predict and measure branching fractions of ${\Omega }_b^{-}$ baryon decays.

    ↳ hep-exhep-ph2 citations
20. 20*

    Dynamical Friction in Gravitational Atoms

    Giovanni Maria Tomaselli🇳🇱 · Thomas F.M. Spieksma🇩🇰 · Gianfranco Bertone🇳🇱

    Due to superradiant instabilities, clouds of ultralight bosons can spontaneously grow around rotating black holes, creating so-called "gravitational atoms". In this work, we study their dynamical effects on binary systems. We first focus on open orbits, showing that the presence of a cloud can increase the cross section for the dynamical capture of a compact object by more than an order of magnitude. We then consider closed orbits and demonstrate that the backreaction of the cloud's ionization on the orbital motion should be identified as dynamical friction. Finally, we study for the first time eccentric and inclined orbits. We find that, while ionization quickly circularizes the binary, it barely affects the inclination angle. These results enable a more realistic description of the dynamics of gravitational atoms in binaries and pave the way for dedicated searches with future gravitational wave detectors.

    ↳ gr-qchep-phhep-thJCAP(2023)·93 citations
21. 21*

    Origin of the Arrow of Time in Quantum Mechanics

    Nemanja Kaloper🇺🇸

    We point out that time's arrow is naturally induced by quantum mechanical evolution, whenever the systems have a very large number $\mathcal{N}$ of non-degenerate states and a Hamiltonian bounded from below. When $\mathcal{N}$ is finite, the arrow is imperfect, since evolution can resurrect past states. In the limit $\mathcal{N}\to \infty$ the arrow is fixed by the "tooth of time": the decay of excited states induced by {\it spontaneous emission} to the ground state, mediated by interactions and a large number of decay products which carry energy and information to infinity. This applies to individual isolated atoms, and does not require a coupling to a separate large heath bath.

    ↳ hep-thastro-ph.COgr-qchep-ph+1Int.J.Mod.Phys.D(2024)·0 citations
22. 22*

    Worldline effective field theory of inspiralling black hole binaries in presence of dark photon and axionic dark matter

    Arpan Bhattacharyya🇮🇳 · Saptaswa Ghosh🇮🇳 · Sounak Pal🇮🇳

    We investigate the correction to the potential that gives rise to the bound orbits and radiation from non-spinning inspiralling binary black holes in a dark matter environment consisting of axion-like particles and dark photons using the techniques of Worldline Effective Field Theory. We compute the conservative dynamics up to $1$PN order for gravitational, electromagnetic, and Proca fields and up to $2$PN order for the scalar field. The effect of axion-electromagnetic coupling ($g_{a\gamma \gamma }$) arises to the conservative dynamics at $2.5$PN order and the kinetic mixing constant ($\gamma$) at $1$PN order. Furthermore, we calculate the radiation due to the various fields present in our theory. We find that the contribution of $g_{a\gamma \gamma }$ to the gravitational radiation appears at $N^{(7)}LO$ and to the scalar radiation appears at $N^{(5)}LO$. We also find that these radiative corrections due to the coupling $g_{a\gamma \gamma }$ vanishes for any orbit confined to a plane because of the existence of a binormal like term in effective radiative action but give rise to non-zero contributions for any orbit that lies in three dimensions. Last but not the least, $\gamma$ contributes to the gravitational radiation at $N^{(2)}LO$ and $N^{(4)}LO$.

    ↳ hep-thgr-qchep-phJHEP(2023)·40 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.