Thu·Aug 5, 2021Thursday·August 5, 2021

1. 01*

   Transversity through Dihadron: a constrained fit

   A. Courtoy🇲🇽

   We present a study of the valence transversity PDF obtained through a constrained fit. The effects of the constraints on the uncertainties of the PDF are explored. We show that the resulting isovector tensor charge is largely undetermined and, hence, compatible with all lattice evaluations.

   hep-phSciPost Phys.Proc.(2022)·0 citations
2. 02*

   Cosmological Strangeness Abundance

   Cheng Tao Yang🇺🇸 · Johann Rafelski🇺🇸

   We investigate the strange particle composition of the early Universe in the hadron epoch $T_h\approx 150\ge T\ge 10$\,MeV. We study strangeness yield in thermal and chemical equilibrium constrained by prescribed entropy per baryon in a charge neutral and strangeness neutral $⟨s-\bar{s}⟩$ Universe. Turning to kinetic processes in a Hubble expanding Universe, we determine conditions at which individual strangeness producing reactions fall out of detailed balance between decay and back-reaction strangeness production rates in presence of decreasing temperature $T$; we allow for weak, electromagnetic, and strong interaction processes. The weak interaction ${\mu }^{\pm }+{\nu }_{\mu }\to K^{\pm }$ freezeout is at $T_f^{K^{\pm }}=33.8\mathrm{MeV}$; the electromagnetic process $l^{-}+l^{+}\to \varphi$ freezeout is at $T_f^{\varphi }=23\sim 25\mathrm{MeV}$; and the hadronic reaction $\pi +\pi \to K$ freezeout is at $T_f^K=19.8\mathrm{MeV}$.

   hep-phPLB(2022)·6 citations
3. 03*

   $t$-channel singularities in cosmology and particle physics

   B. Grzadkowski🇵🇱 · M. Iglicki🇵🇱 · S. Mrówczyński🇵🇱

   The $t$-channel singularity of a cross-section for a binary $2\to 2$ scattering process occurs when a particle exchanged in the $t$ channel is kinematically allowed to be on its mass-shell, that is when the process can be viewed as a sequence of two physical subprocesses: a two-body decay $1\to 2$ and an inverse decay $2\to 1$. We derive conditions for the singularity to be present in a binary process. A class of divergent cross sections for Standard Model processes has been determined and illustrated by the weak analog of the Compton scattering $Z{e}^{-}\to Z{e}^{-}$. After critically reviewing regularization methods proposed in literature, we discuss singular processes which occur in a medium composed of particles in thermal equilibrium. The medium is shown to regulate the singularities naturally as particles acquire a finite width. We demonstrate a possible cosmological application by calculating thermally averaged cross section for an elastic scattering within a simple scalar model. The cross section, which is divergent in vacuum, becomes finite when the process occurs in a thermal bath due to the imaginary self-energy of the $t$-channel mediator computed within the Keldysh-Schwinger formalism.

   hep-phNPB(2022)·17 citations
4. 04*

   Impact of heavy-quark production measurements in the CT18 global QCD analysis of PDFs

   Marco Guzzi🇺🇸 · Pavel Nadolsky🇺🇸 · Keping Xie🇺🇸

   We discuss the impact of heavy-flavor production measurements in semi-inclusive deep inelastic scattering at HERA on the CTEQ-TEA PDFs. In particular, we study the impact of the latest charm and bottom production measurements from the H1 and ZEUS collaborations on the gluon, and the interplay of these measurements with the data ensemble of the recent CT18 global QCD analysis.

   hep-phSciPost Phys.Proc.(2022)·4 citations
5. 05*

   Revisiting the Okubo-Marshak argument

   Christian Gaß🇩🇪 · José M. Gracia-Bondía🇪🇸 · Jens Mund🇧🇷

   Modular localization and the theory of string-localized fields have revolutionized several key aspects of quantum field theory. They reinforce the contention that local symmetry emerges directly from quantum theory, but global gauge invariance remains in general an unwarranted assumption, to be examined case by case. Armed with those modern tools, we reconsider here the classical Okubo-Marshak argument on the non-existence of a "strong CP problem" in quantum chromodynamics.

   hep-phhep-thSymmetry(2021)·11 citations
6. 06*

   Twist-3 Double Spin Asymmetries in Drell-Yan Processes

   M.C. Hu🇨🇳 · J.P. Ma🇨🇳 · Z.Y. Pang🇨🇳 · G.P. Zhang🇨🇳

   We study double spin asymmetries in Drell-Yan processes in which one initial hadron is transversely polarized and another one is longitudinally polarized. The complete part of the hadronic tensor relevant to asymmetries is derived. This part consists of twist-2 and twist-3 parton distributions and is gauge invariant. We construct some observables which can be used to extract these parton distributions from experimental measurements.

   hep-phPRD(2022)·2 citations
7. 07*

   Radiative M1 transitions of heavy baryons: Effective Quark Mass Scheme

   Avijit Hazra🇮🇳 · Saheli Rakshit🇮🇳 · Rohit Dhir🇮🇳

   We calculate the magnetic moments of ground state $J^P={\frac{1}{2}}^{+}$ and $J^P={\frac{3}{2}}^{+}$ heavy flavor charm and bottom baryon states employing the concept of effective mass based on single gluon exchange interaction coupling to the spectator quarks in the non-relativistic quark model. We exploit the current experimental information in the heavy flavor sector to estimate the interaction contributions to get the effective masses of the quarks inside the baryons. We study the spin ${\frac{1}{2}}^{{}^{\prime }+}\to {\frac{1}{2}}^{+}$, ${\frac{3}{2}}^{+}\to {\frac{1}{2}}^{+}$, and ${\frac{3}{2}}^{+}\to {\frac{1}{2}}^{{}^{\prime }+}$ transition moments for these baryons. We make robust predictions of the radiative M1 decay widths of singly, doubly, and triply heavy flavored baryons.

   hep-phhep-exPRD(2021)·37 citations
8. 08*

   New form of kernel in equation for Nakanishi function

   V.A. Karmanov🇷🇺

   The Bethe-Salpeter amplitude $\Phi (k,p)$ is expressed, by means of the Nakanishi integral representation, via a smooth function $g(\gamma ,z)$. This function satisfies a canonical equation $g=Ng$. However, calculations of the kernel $N$ in this equation, presented previously, were restricted to one-boson exchange and, depending on method, dealt with complex multivalued functions. Although these difficulties are surmountable, but in practice, they complicate finding the unambiguous result. In the present work, an unambiguous expression for the kernel $N$ in terms of real functions is derived. For the one-boson scalar exchange, the explicit formula for $N$ is found. With this equation and kernel, the binding energies, calculated previously, are reproduced. Their finding, as well as calculation of the Bethe-Salpeter amplitude in the Minkowski space, become not more difficult than in the Euclidean one. The method can be generalized to any kernel given by irreducible Feynman graph. This generalization is illustrated by example of the cross-ladder kernel.

   hep-phnucl-thPRD(2021)·5 citations
9. 09*

   Left-Right symmetric fermions and sterile neutrinos from complex split biquaternions and bioctonions

   Vatsalya Vaibhav🇮🇳 · Tejinder P. Singh🇮🇳

   In this article we investigate the application of complex split biquaternions and bioctonions to the standard model. We show that the Clifford algebras Cl(3) and Cl(7) can be used for making left-right symmetric fermions. Hence we incorporate right-handed neutrinos in the division algebras based approach to the standard model. The right-handed neutrinos, also known as sterile neutrinos, are a potential dark-matter candidate. We discuss the left-right symmetric fermions and their phenomenology using the division algebra approach. We describe the gauge groups associated with the left-right symmetric model and prospects for unification through division algebras. We investigate the possibility of obtaining three generations of fermions and charge/mass ratios through the exceptional Jordan algebra $J_3(O)$ and the exceptional groups $F_4$ and $E_6$.

   hep-phgr-qchep-thAdv.Appl.Clifford Algebras(2023)·30 citations
10. 10*

    Predicting another doubly charmed molecular resonance $T_{cc}^{\prime +}(3876)$

    Rui Chen🇨🇳 · Qi Huang🇨🇳 · Xiang Liu🇨🇳 · Shi-Lin Zhu🇨🇳

    The isospin breaking effect plays an essential role in generating hadronic molecular states with a very tiny binding energy. Very recently, the LHCb Collaboration observed a very narrow doubly charmed tetraquark $T_{cc}^{+}$ in the $D^0{D}^0\pi$ mass spectrum, which lies just below the $D^0{D}^{\ast +}$ threshold around 273 keV. In this work, we study the $D^0{D}^{\ast +}/D^{+}{D}^{\ast 0}$ interactions with the one-boson-exchange effective potentials and consider the isospin breaking effect carefully. We not only reproduce the mass of the newly observed $T_{cc}^{+}$ very well in the doubly charmed molecular tetraquark scenario, but also predict the other doubly charmed partner resonance $T_{cc}^{\prime +}$ with $m=3876\text{MeV}$, and $\Gamma =412\text{keV}$. The prime decay modes of the $T_{cc}^{\prime +}$ are $D^0{D}^{+}\gamma$ and $D^{+}{D}^0{\pi }^0$. The peculiar characteristic mass spectrum of the $D^0{D}^{\ast +}/D^{+}{D}^{\ast 0}$ molecular systems can be applied to identify the doubly charmed molecular states.

    hep-phhep-exhep-latPRD(2021)·86 citations
11. 11*

    Subnucleon fluctuations in coherent and incoherent ultra-peripheral AA collisions at LHC and RHIC with the Sartre event generator

    Tobias Toll🇮🇳

    Sartre has been extensively used for describing photon-nuclei processes at the electron-ion collider (EIC) as well as ultra-peripheral collisions (UPC) at LHC and RHIC. Sartre is an event generator which implements the dipole model for DIS, and models the transverse geometry of the target nucleus or proton in coordinate space. It uses the Good-Walker mechanism for simulating fluctuations which contribute to the incoherent cross section for which the target breaks up after the interaction. With improved precision of UPC measurements in the last years, a detailed test of the dipole model has become possible, and Sartre's model was found lacking. In these proceedings we add subnucleon fluctuations to the nucleus and show that this is sufficient for describing the vast majority of the present measurements. We also find that for larger momentum transfers in the nucleus, which probes gluon fluctuations at higher resolution, the current complexity of the model may not suffice. Future measurements at the LHC, RHIC and especially the EIC has the potential to reveal these gluon vacuum fluctuations and glean novel insights into the self-interacting quantum field of QCD.

    hep-phSciPost Phys.Proc.(2022)·2 citations
12. 12*

    JAM small-$x$ helicity phenomenology

    Daniel Adamiak🇺🇸

    We present the first-ever description the world data on the $g_1^{p,n}$ structure function at small Bjorken $x$ using evolution equations in $x$ derived from first principles QCD. This is a Monte-Carlo analysis within the JAM global framework that allows us to fit all existing polarized DIS data below $x<0.1$ as well as predict future measurements of small $x$ $g_1^{p,n}$ at the EIC. This is a necessary step in determining the quark helicity PDFs and, ultimately, the quark contribution to the proton spin.

    hep-phnucl-th1 citation
13. 13*

    Soft-photon radiative corrections to the $e^{-}p\to e^{-}p{l}^{-}{l}^{+}$ process

    Matthias Heller🇩🇪 · Niklas Keil🇩🇪 · Marc Vanderhaeghen🇩🇪

    We calculate the leading-order QED radiative corrections to the process $e^{-}p\to e^{-}p{l}^{-}{l}^{+}$ in the soft-photon approximation, in two different energy regimes which are of relevance to extract nucleon structure information. In the low-energy region, this process is studied to better constrain the hadronic corrections to precision muonic Hydrogen spectroscopy. In the high-energy region, the beam-spin asymmetry for double virtual Compton scattering allows to directly access the Generalized Parton Distributions. We find that the soft-photon radiative corrections have a large impact on the cross sections and are therefore of paramount importance to extract the nucleon structure information from this process. For the forward-backward asymmetry the radiative corrections are found to affect the asymmetry only around or below the 1\% level, whereas the beam-spin asymmetry is not affected at all in the soft-photon approximation, which makes them gold-plated observables to extract nucleon structure information in both the low- and high-energy regimes.

    hep-phnucl-thPRD(2021)·4 citations
14. 14*

    Proton image and momentum distributions from light-front dynamics

    Emanuel Ydrefors🇧🇷 · Tobias Frederico🇧🇷

    We apply a dynamical three-constituent quark light-front model to study the proton. The dynamics is based on the notion of a diquark (bound or virtual) as the dominant interaction channel, which paramaterizes a contact interaction between the quarks in order to build the three-body Faddeev Bethe-Salpeter equations for the valence state, and we focus on the totally symmetric part of the wave function. The Dirac electromagnetic form factor is used to fix the model parameters, and the valence wave function is obtained. From that we investigate its Ioffe-time image, non-polarized longitudinal and transverse momentum distributions, and the double momentum distribution.

    hep-phPRD(2021)·7 citations
15. 15*

    Modular symmetry at level 6 and a new route towards finite modular groups

    Cai-Chang Li🇨🇳 · Xiang-Gan Liu🇨🇳 · Gui-Jun Ding🇨🇳

    We propose to construct the finite modular groups from the quotient of two principal congruence subgroups as $\Gamma (N^{\prime })/\Gamma (N")$, and the modular group $SL(2,\mathbb{Z})$ is extended to a principal congruence subgroup $\Gamma (N^{\prime })$. The original modular invariant theory is reproduced when $N^{\prime }=1$. We perform a comprehensive study of ${\Gamma }_6^{\prime }$ modular symmetry corresponding to $N^{\prime }=1$ and $N"=6$, five types of models for lepton masses and mixing with ${\Gamma }_6^{\prime }$ modular symmetry are discussed and some example models are studied numerically. The case of $N^{\prime }=2$ and $N"=6$ is considered, the finite modular group is $\Gamma (2)/\Gamma (6)\cong T^{\prime }$, and a benchmark model is constructed.

    hep-phJHEP(2021)·58 citations
16. 16*

    Tumblers: A Novel Collider Signature for Long-Lived Particles

    Keith R. Dienes🇺🇸 · Doojin Kim🇺🇸 · Tara Leininger🇺🇸 · Brooks Thomas🇺🇸

    In this paper, we point out a novel signature of physics beyond the Standard Model which could potentially be observed both at the Large Hadron Collider (LHC) and at future colliders. This signature, which emerges naturally within many proposed extensions of the Standard Model, results from the multiple displaced vertices associated with the successive decays of unstable, long-lived particles along the same decay chain. We call such a sequence of displaced vertices a "tumbler." We examine the prospects for observing tumblers at the LHC and assess the extent to which tumbler signatures can be distinguished from other signatures of new physics which also involve multiple displaced vertices within the same collider event. As part of this analysis, we also develop a procedure for reconstructing the masses and lifetimes of the particles involved in the corresponding decay chains. We find that the prospects for discovering and distinguishing tumblers can be greatly enhanced by exploiting precision timing information such as would be provided by the CMS timing layer at the high-luminosity LHC. Our analysis therefore provides strong additional motivation for continued efforts to improve the timing capabilities of collider detectors at the LHC and beyond.

    hep-phhep-exPRD(2022)·16 citations
17. 17*

    Investigation of the background in coherent $J/\psi$ production at the EIC

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

    Understanding various fundamental properties of nucleons and nuclei are among the most important scientific goals at the upcoming Electron-Ion Collider (EIC). With the unprecedented opportunity provided by the next-generation machine, the EIC might provide definitive answers to many standing puzzles and open questions in modern nuclear physics. Here we investigate one of the golden measurements proposed at the EIC, which is to obtain the spatial gluon density distribution within a lead ($Pb$) nucleus. The proposed experimental process is the exclusive $J/\psi$ vector-meson production off the $Pb$ nucleus - $e+Pb\to e^{\prime }+J/\psi +P{b}^{\prime }$. The Fourier transformation of the momentum transfer $|t|$ distribution of the coherent diffraction is the transverse gluon spatial distribution. In order to measure it, the experiment has to overcome an overwhelmingly large background arising from the incoherent diffractive production, where the nucleus $P{b}^{\prime }$ mostly breaks up into fragments of particles in the far-forward direction close to the hadron-going beam rapidity. In this paper, we systematically study the rejection of incoherent $J/\psi$ production by vetoing products from these nuclear breakups - protons, neutrons, and photons, which is based on the BeAGLE event generator and the most up-to-date EIC Far-forward Interaction Region design. The achieved vetoing efficiency, the ratio between the number of vetoed events and total incoherent events, ranges from about 80% - 99% depending on $|t|$, which can resolve at least the first minimum of the coherent diffractive distribution based on the Sar$t$re model. Experimental and accelerator machine challenges as well as potential improvements are discussed.

    ↳ nucl-exhep-exhep-phnucl-thPRD(2021)·28 citations
18. 18*

    Analyticity and Unitarity for Cosmological Correlators

    Lorenzo Di Pietro🇮🇹 · Victor Gorbenko🇺🇸 · Shota Komatsu🇨🇭

    We study the fundamentals of quantum field theory on a rigid de Sitter space. We show that the perturbative expansion of late-time correlation functions to all orders can be equivalently generated by a non-unitary Lagrangian on a Euclidean AdS geometry. This finding simplifies dramatically perturbative computations, as well as allows us to establish basic properties of these correlators, which comprise a Euclidean CFT. We use this to infer the analytic structure of the spectral density that captures the conformal partial wave expansion of a late-time four-point function, to derive an OPE expansion, and to constrain the operator spectrum. Generically, dimensions and OPE coefficients do not obey the usual CFT notion of unitarity. Instead, unitarity of the de Sitter theory manifests itself as the positivity of the spectral density. This statement does not rely on the use of Euclidean AdS Lagrangians and holds non-perturbatively. We illustrate and check these properties by explicit calculations in a scalar theory by computing first tree-level, and then full one-loop-resummed exchange diagrams. An exchanged particle appears as a resonant feature in the spectral density which can be potentially useful in experimental searches.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2022)·207 citations
19. 19*

    The exotic meson ${\pi }_1(1600)$ with $J^{PC}=1^{-+}$ and its decay into $\rho (770)\pi$

    M.G. Alexeev · G.D. Alexeev · A. Amoroso · V. Andrieux · V. Anosov · K. Augsten · W. Augustyniak · C.D.R. Azevedo · B. Badelek · F. Balestra · M. Ball · J. Barth and 184 other authors

    We study the spin-exotic $J^{PC}=1^{-+}$ amplitude in single-diffractive dissociation of 190 GeV$/c$ pions into ${\pi }^{-}{\pi }^{-}{\pi }^{+}$ using a hydrogen target and confirm the ${\pi }_1(1600)\to \rho (770)\pi$ amplitude, which interferes with a nonresonant $1^{-+}$ amplitude. We demonstrate that conflicting conclusions from previous studies on these amplitudes can be attributed to different analysis models and different treatment of the dependence of the amplitudes on the squared four-momentum transfer and we thus reconcile their experimental findings. We study the nonresonant contributions to the ${\pi }^{-}{\pi }^{-}{\pi }^{+}$ final state using pseudo-data generated on the basis of a Deck model. Subjecting pseudo-data and real data to the same partial-wave analysis, we find good agreement concerning the spectral shape and its dependence on the squared four-momentum transfer for the $J^{PC}=1^{-+}$ amplitude and also for amplitudes with other $J^{PC}$ quantum numbers. We investigate for the first time the amplitude of the ${\pi }^{-}{\pi }^{+}$ subsystem with $J^{PC}=1^{--}$ in the $3\pi$ amplitude with $J^{PC}=1^{-+}$ employing the novel freed-isobar analysis scheme. We reveal this ${\pi }^{-}{\pi }^{+}$ amplitude to be dominated by the $\rho (770)$ for both the ${\pi }_1(1600)$ and the nonresonant contribution. We determine the $\rho (770)$ resonance parameters within the three-pion final state. These findings largely confirm the underlying assumptions for the isobar model used in all previous partial-wave analyses addressing the $J^{PC}=1^{-+}$ amplitude.

    ↳ hep-exhep-phPRD(2022)·46 citations
20. 20*

    Anisotropic turbulence in relativistic plasmas

    Abhisek Saha🇮🇳 · Soma Sanyal🇮🇳

    Signs of turbulence have been observed at the relativistic heavy ion collision at high collision energies. We study the signatures of turbulence in this system and find that there are significant departures from isotropic turbulence in the initial stages of the collision. Since the anisotropic fluctuations are sub leading to the isotropic fluctuations, the Kolmogorov spectrum can usually be obtained even for the initial stages. However, the energy spectrum and the temperature fluctuations indicate deviations from isotropic turbulence. Since a strong momentum anisotropy exists between the transverse and the longitudinal plane, we study the energy density spectrum in these two planes. The geometrical anisotropy is reflected in the anisotropic turbulence generated in the rotating plasma and we find that the scaling exponent is different in the two planes. We find that the scaling exponents in the longitudinal plane are independent of centrality while the scaling exponent in the transverse plane depends on the centrality range. We also obtain the temperature spectrum in the initial stages. The spectrum deviates from the Gaussian spectra expected for an isotropic turbulence. All these seem to indicate that the large scale momentum anisotropy persists in the smaller length scales for the relativistic heavy ion collisions.

    ↳ nucl-thhep-phEur.Phys.J.Plus(2022)·1 citation
21. 21*

    Free-free background radiation from accreting primordial black holes

    Hiroyuki Tashiro🇯🇵 · Katsuya T. Abe🇯🇵 · Teppei Minoda🇯🇵

    Baryonic gas falling onto a primordial black hole (PBH) emits photons via the free-free process. These photons can contribute the diffuse free-free background radiation in the frequency range of the cosmic microwave background radiation (CMB). We show that the intensity of the free-free background radiation from PBHs depends on the mass and abundance of PBHs. In particular, considering the growth of a dark matter (DM) halo around a PBH by non-PBH DM particles strongly enhances the free-free background radiation. Large PBH fraction increase the signal of the free-free emission. However, large PBH fraction also can heat the IGM gas and, accordingly, suppresses the accretion rate. As a result, the free-free emission decreases when the PBH fraction is larger than 0.1. We find that the free-free emission from PBHs in the CMB and radio frequency is much lower than the CMB blackbody spectrum and the observed free-free emission component in the background radiation. Therefore, it is difficult to obtain the constraint from the free-free emission observation. However further theoretical understanding and observation on the free-free emission from cosmological origin is helpful to study the PBH abundance with the stellar mass.

    ↳ astro-ph.COgr-qchep-ph1 citation
22. 22*

    gammaALPs: An open-source python package for computing photon-axion-like-particle oscillations in astrophysical environments

    Manuel Meyer🇩🇪 · James Davies🇬🇧 · Julian Kuhlmann🇩🇪

    Axions and axion-like particles (ALPs) are hypothetical particles that occur in extensions of the Standard Model and are candidates for cold dark matter. They could be detected through their oscillations into photons in the presence of external electromagnetic fields. gammaALPs is an open-source python framework that computes the oscillation probability between photons and axions/ALPs. In addition to solving the photon-ALP equations of motion, gammaALPs includes models for magnetic fields in different astrophysical environments such as jets of active galactic nuclei, intra-cluster and intergalactic media, and the Milky Way. Users are also able to easily incorporate their own custom magnetic-field models. We review the basic functionality and features of gammaALPs, which is heavily based on other open-source scientific packages such as numpy and scipy. Although focused on gamma-ray energies, gammaALPs can be easily extended to arbitrary photon energies.

    ↳ astro-ph.HEhep-phPoS(2021)·56 citations
23. 23*

    Derivative corrections to the Heisenberg-Euler effective action

    Felix Karbstein🇩🇪

    We show that the leading derivative corrections to the Heisenberg-Euler effective action can be determined efficiently from the vacuum polarization tensor evaluated in a homogeneous constant background field. After deriving the explicit parameter-integral representation for the leading derivative corrections in generic electromagnetic fields at one loop, we specialize to the cases of magnetic- and electric-like field configurations characterized by the vanishing of one of the secular invariants of the electromagnetic field. In these cases, closed-form results and the associated all-orders weak- and strong-field expansions can be worked out. One immediate application is the leading derivative correction to the renowned Schwinger-formula describing the decay of the quantum vacuum via electron-positron pair production in slowly-varying electric fields.

    ↳ hep-thhep-phJHEP(2021)·17 citations
24. 24*

    Extending the sample of core-collapse supernovae for searches of axion-like-particle induced gamma-ray bursts with the Fermi LAT

    Manuel Meyer🇩🇪 · Tanja Petrushevska (for the Fermi-LAT collaboration)🇸🇮

    During a core-collapse supernova (SN), axion-like particles (ALPs) could be produced through the Primakoff process and subsequently convert into gamma rays in the magnetic field of the Milky Way. Using a sample of well studied extragalactic SNe at optical wavelengths, we estimate the time of the core collapse and search for a coincident gamma-ray burst with the Fermi Large Area Telescope (LAT). Under the assumption that at least one SN was contained within the LAT field of view, we exclude photon-ALP couplings within a factor of $\sim$5 of previous limits from SN1987A. With the increasing number of SNe observed with optical surveys, our results demonstrate the potential to probe ALP dark matter with combined optical and gamma-ray observations. We also provide preliminary results for the estimation of explosion times of 15 close-by SNe observed recently with ZTF. Our findings show that the explosion time can be estimated within one day (statistical uncertainty only) making them promising targets for a follow-up LAT analysis.

    ↳ astro-ph.HEhep-phPoS(2021)·2 citations
25. 25*

    Charmonium in electromagnetic and vortical fields

    Jiaxing Zhao🇨🇳 · Shile Chen🇨🇳 · Pengfei Zhuang🇨🇳

    Due to larger mass and earlier production, heavy quark(quarkonium) can be sensitive probes to investigate the fast decaying electromagnetic and vortical fields produced in heavy-ion collisions. The non-relativistic Schroedinger-like equation for heavy quarks under strong electromagnetic fields in the rotating frame is deduced and used to construct the two-body equation for the charmonium system. The effective potential between charm and anti-charm becomes anisotropic in electromagnetic and vortical fields, especially along the direction of the Lorentz force. The vorticity will affect this asymmetry property largely and catalyze the transition from strong interaction dominant bound state to electromagnetic and vortical interaction controlled anisotropic bound state. It is possible to be realized in high-energy nuclear collisions.

    ↳ nucl-thhep-phEPJ Web Conf.(2022)·1 citation
26. 26*

    Implications of the Cosmic Birefringence Measurement for the Axion Dark Matter Search

    Ippei Obata🇩🇪

    We show that a recent constraint on the cosmic birefringence effect due to dark energy can be related to the constraints on the coupling of axion dark matter to photon, by relying on a simple model of two-axion alignment mechanism with periodic potentials. Owing to the alignment of the potentials, one linear combination of two fields provides a nearly flat direction and acts as dark energy, whereas the other combination provides a steep direction and acts as dark matter. This scenario solves the known conceptual issues of one-field model for dark energy and predicts the connection between seemingly disparate constraints on the dark sectors of our universe.

    ↳ astro-ph.COhep-phhep-thJCAP(2022)·50 citations
27. 27*

    Geometrical origins of the Universe dark sector: string-inspired torsion and anomalies as seeds for inflation and dark matter

    Nick E. Mavromatos🇬🇧

    In a modest attempt to present potentially new paradigms in Cosmology, including its inflationary epoch, and initiate discussions, I review in this article some novel, string-inspired cosmological models, which entail a purely geometrical origin of the Dark sector of the Universe but also of its observed matter-antimatter asymmetry. The models contain gravitational (string-model independent, Kalb-Ramond (KR)) axion fields coupled to primordial gravitational anomalies via CP-violating interactions. The anomaly terms are four-space-time-dimensional remnants of the Green-Schwarz counterterms appearing in the definition of the field strength of the spin-one antisymmetric tensor field of the (bosonic) massless gravitational string multiplet, which also plays the rôle of a totally antisymmetric component of torsion. I show how in such cosmologies the presence of primordial gravitational waves can lead to anomaly condensates and dynamical inflation of a "running-vacuum-model" type, without external inflatons, but also to leptogenesis in the radiation era due to anomaly-induced Lorentz and CPT Violating KR axion backgrounds. I also discuss how the torsion-related KR-axion could acquire a mass during the QCD epoch, thus playing the role of (a component of) Dark Matter. Phenomenological considerations of the inflationary and post-inflationary (in particular, modern) eras of the model are briefly discussed, including its potential for alleviating the observed tensions in the cosmological data of the current epoch.

    ↳ gr-qchep-phhep-thPhil.Trans.Roy.Soc.Lond.A(2022)·32 citations
28. 28*

    Transient fluid dynamics with general matching conditions: a first study from the method of moments

    Gabriel S. Rocha🇧🇷 · Gabriel S. Denicol🇧🇷

    Recent works have revealed that matching conditions play a major role on general consistency properties of relativistic fluid dynamics such as causality, stability and wellposedness of the equations of motion. In this paper we derive transient fluid dynamics from kinetic theory, using the method of moments as proposed by Israel and Stewart, without imposing an specific matching condition. We then investigate how the equations of motion and their corresponding transport coefficients are affected by the choice of matching condition.

    ↳ nucl-thhep-phhep-thPRD(2021)·36 citations
29. 29*

    A FAIR and AI-ready Higgs boson decay dataset

    Yifan Chen🇺🇸 · E. A. Huerta🇺🇸 · Javier Duarte🇺🇸 · Philip Harris🇺🇸 · Daniel S. Katz🇺🇸 · Mark S. Neubauer🇺🇸 · Daniel Diaz🇺🇸 · Farouk Mokhtar🇺🇸 · Raghav Kansal🇺🇸 · Sang Eon Park🇺🇸 · Volodymyr V. Kindratenko🇺🇸 · Zhizhen Zhao🇺🇸 · Roger Rusack🇺🇸

    To enable the reusability of massive scientific datasets by humans and machines, researchers aim to adhere to the principles of findability, accessibility, interoperability, and reusability (FAIR) for data and artificial intelligence (AI) models. This article provides a domain-agnostic, step-by-step assessment guide to evaluate whether or not a given dataset meets these principles. We demonstrate how to use this guide to evaluate the FAIRness of an open simulated dataset produced by the CMS Collaboration at the CERN Large Hadron Collider. This dataset consists of Higgs boson decays and quark and gluon background, and is available through the CERN Open Data Portal. We use additional available tools to assess the FAIRness of this dataset, and incorporate feedback from members of the FAIR community to validate our results. This article is accompanied by a Jupyter notebook to visualize and explore this dataset. This study marks the first in a planned series of articles that will guide scientists in the creation of FAIR AI models and datasets in high energy particle physics.

    ↳ hep-excs.AIcs.DBhep-phSci.Data(2022)·21 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.