Wed·Feb 23, 2022Wednesday·February 23, 2022

1. 01*

   Charged Dark Matter in Supersymmetric Twin Higgs models

   Marcin Badziak🇵🇱 · Giovanni Grilli di Cortona🇮🇹 · Keisuke Harigaya🇨🇭 · Michał Łukawski🇵🇱

   Supersymmetric Twin Higgs models ameliorate the fine-tuning of the electroweak scale originating from the heavy scalar top partners required by the non-discovery of them at the Large Hadron Collider. If the Lightest Supersymmetric Particle resides in the twin sector, it may play the role of dark matter even if it is charged under twin gauge interactions. We show that the twin stau is a viable candidate for charged dark matter, even if the twin electromagnetic gauge symmetry is unbroken, with thermal relic abundance that naturally matches the observed dark matter abundance. A wide parameter space satisfies all the experimental constraints including those on dark matter self-interactions. Twin stau dark matter can be observed in future direct detection experiments such as LUX-ZEPLIN. The stau has a mass in the range of 300-500 GeV, and in the minimal scenario, has a decay length long enough to be observed as a disappearing track or a long-lived particle at the Large Hadron Collider.

   hep-phJHEP(2022)·12 citations
2. 02*

   Learning from Radiation at a Very High Energy Lepton Collider

   Siyu Chen🇨🇭 · Alfredo Glioti🇨🇭 · Riccardo Rattazzi🇨🇭 · Lorenzo Ricci🇨🇭 · Andrea Wulzer🇮🇹

   We study the potential of lepton collisions with about $10\text{ TeV}$ center of mass energy to probe Electroweak, Higgs and Top short-distance physics at the $100\text{ TeV}$ scale, pointing out the interplay with the long-distance ($100\text{ GeV}$) phenomenon of Electroweak radiation. On one hand, we find that sufficiently accurate theoretical predictions require the resummed inclusion of radiation effects, which we perform at the double logarithmic order. On the other hand, we notice that short-distance physics does influence the emission of Electroweak radiation. Therefore the investigation of the radiation pattern can enhance the sensitivity to new short-distance physical laws. We illustrate these aspects by studying Effective Field Theory contact interactions in di-fermion and di-boson production, and comparing cross-section measurements that require or that exclude the emission of massive Electroweak bosons. The combination of the two types of measurements is found to enhance the sensitivity to the new interactions. Based on these results, we perform sensitivity projections to Higgs and Top Compositeness and to minimal $Z^{\prime }$ new physics scenarios at future muon colliders.

   hep-phhep-exhep-thJHEP(2022)·53 citations
3. 03*

   Complementary collider and astrophysical probes of multi-component Dark Matter

   Jaime Hernandez-Sanchez🇲🇽 · Venus Keus🇫🇮 · Stefano Moretti🇬🇧 · Dorota Sokolowska🇵🇱

   We study a new physics scenario with two inert and one active scalar doublets, hence a 3-Higgs Doublet Model (3HDM). We impose a $Z_2\times Z_2^{\prime }$ symmetry onto such a 3HDM with one inert doublet odd under the $Z_2$ transformation and the other odd under the $Z_2^{\prime }$ one. Such a construction leads to a two-component Dark Matter (DM) model. It has been shown that, when there is a sufficient mass difference between the two DM candidates, it is possible to probe the light DM candidate in the nuclear recoil energy in direct detection experiments and the heavy DM component in the photon flux in indirect detection experiments. With the DM masses at the electroweak scale, we show that, independently of astrophysical probes, this model feature can be tested at the Large Hadron Collider via scalar cascade decays in $2\ell +{\cancel{E}}_T$ final states. We study several observable distributions whose shapes hint at the presence of the two different DM candidates.

   hep-phastro-ph.COJHEP(2023)·15 citations
4. 04*

   Standard Model prediction for paramagnetic EDMs

   Yohei Ema🇺🇸 · Ting Gao🇺🇸 · Maxim Pospelov🇺🇸

   Standard Model $CP$ violation associated with the phase of the Cabibbo-Kobayashi-Maskawa quark mixing matrix is known to give small answers for the EDM observables. Moreover, predictions for the EDMs of neutrons and diamagnetic atoms suffer from considerable uncertainties. We point out that the $CP$-violating observables associated with the electron spin (paramagnetic EDMs) are dominated by the combination of the electroweak penguin diagrams and $\Delta I=1/2$ weak transitions in the baryon sector, and are calculable within chiral perturbation theory. The predicted size of the semileptonic operator $C_S$ is $7\times 10^{-16}$ which corresponds to the equivalent electron EDM $d_e^{\mathrm{eq}}=1.0\times 10^{-35}e\mathrm{cm}$. While still far from the current observational limits, this result is three orders of magnitude larger than previously believed.

   hep-phhep-exnucl-thPRL(2022)·76 citations
5. 05*

   Magnetic field induced corrections to the NJL model coupling constant from vacuum polarization

   Thiago H. Moreira🇧🇷 · Fabio L. Braghin🇧🇷

   Magnetic field dependent corrections for the coupling constant of the Nambu-Jona-Lasinio model are calculated by considering the one-loop background field method. These coupling constants turn out to break chiral and flavor symmetries and they lead to a slight improvement of the numerical values of the up and down quark condensates when compared to results from lattice QCD. The corresponding magnetic field dependencies of the neutral pion and kaon masses are also presented and compared with available lattice QCD calculations. The resulting magnetic field correction to the $\eta -{\eta }^{\prime }$ mixing angle is also estimated.

   hep-phnucl-thPRD(2022)·16 citations
6. 06*

   Implications of the first evidence for coherent elastic scattering of reactor neutrinos

   Jiajun Liao🇨🇳 · Hongkai Liu🇮🇱 · Danny Marfatia🇺🇸

   The recent evidence for coherent elastic neutrino-nucleus scattering (CE$\nu$NS) in the NCC-1701 germanium detector using antineutrinos from the Dresden-II nuclear reactor is in good agreement with standard model expectations. However, we show that a $2\sigma$ improvement in the fit to the data can be achieved if the quenching factor is described by a modified Lindhard model. We also place constraints on the parameter space of a light vector or scalar mediator that couples to neutrinos and quarks, and on a neutrino magnetic moment. We demonstrate that the constraints are quite sensitive to the quenching factor at low recoil energies by comparing constraints for the standard Lindhard model with those by marginalizing over the two parameters of the modified Lindhard model.

   hep-phhep-exnucl-exnucl-thPRD(2022)·30 citations
7. 07*

   The pole counting rule and XYZ states

   Hao Chen🇨🇳 · Hong-Rong Qi🇨🇳

   The pole counting rule is a powerful and model-independent method to distinguish a confining state from a hadronic molecule. It has been applied to the explorations of $X(6900)$, $X_1(2900)$ as well as $Z_c(3900)$, $X(3872)$, $X(4660)$, etc.. For $X(6900)$, both a confining state and a molecular state are not excluded, because lacking of enough data. For $X_1(2900)$, the analysis shows that it should be a ${\bar{D}}_{1}K$ molecule, with $J^P=1^{-}$ and an iso-singlet interpretation is much more favorable. Finally, it is noted that almost all XYZ particles with exotic quantum numbers can be interpreted as hadronic molecules. The $X(3872)$ is, however, more like a charmonium.

   hep-phPoS(2024)·1 citation
8. 08*

   Neural Network QCD analysis of charged hadron Fragmentation Functions in the presence of SIDIS data

   Maryam Soleymaninia🇮🇷 · Hadi Hashamipour🇮🇷 · Hamzeh Khanpour🇮🇷

   In this paper, we present a QCD analysis to extract the Fragmentation Functions (FFs) of unidentified light charged hadron entitled as SHK22.h from high-energy lepton-lepton annihilation and lepton-hadron scattering data sets. This analysis includes the data from all available single inclusive electron-positron annihilation (SIA) processes and semi-inclusive deep-inelastic scattering (SIDIS) measurements for the unidentified light charged hadron productions. The SIDIS data which has been measured by the COMPASS experiment could allow the flavor dependence of the FFs to be well constrained. We exploit the analytic derivative of the Neural Network (NN) for fitting of FFs at next-to-leading-order (NLO) accuracy in the perturbative QCD (pQCD). The Monte Carlo method is implied for all sources of experimental uncertainties and the Parton distribution functions (PDFs) as well. Very good agreements are achieved between the SHK22.h FFs set and the most recent QCD fits available in literature, namely JAM20 and NNFF1.1h. In addition, we discuss the impact arising from the inclusion of SIDIS data on the extracted light-charged hadron FFs. The global QCD resulting at NLO for charged hadron FFs provides valuable insights for applications in present and future high-energy measurement of charged hadron final state processes.

   hep-phhep-exPRD(2022)·19 citations
9. 09*

   Hadronic Vacuum Polarization and the MUonE proposal

   David Greynat🇫🇷 · Eduardo de Rafael🇫🇷

   The MUonE proposal at the CERN SPS consists in extracting the value of the hadronic vacuum polarization self-energy function (HVP) from its contribution to the differential cross-section of elastic muon-electron scattering. The HVP contribution to the muon anomalous magnetic moment can then be obtained from a weighted integral of the measured HVP self-energy function. This, however, requires a knowledge of the HVP function in its full integration domain. This paper discusses a procedure to reconstruct the HVP function in the regions not directly accessible to measurement. The method is based on the so-called transfer theorems, due to Flajolet and Odlyzko, which we explain and adapt to HVP.

   hep-phhep-exhep-latJHEP(2022)·11 citations
10. 10*

    Bounds on new physics with data of the Dresden-II reactor experiment and COHERENT

    Pilar Coloma🇪🇸 · Ivan Esteban🇺🇸 · M. C. Gonzalez-Garcia🇪🇸 · Leire Larizgoitia🇪🇸 · Francesc Monrabal🇪🇸 · Sergio Palomares-Ruiz🇪🇸

    Coherent elastic neutrino-nucleus scattering was first experimentally established five years ago by the COHERENT experiment using neutrinos from the spallation neutron source at Oak Ridge National Laboratory. The first evidence of observation of coherent elastic neutrino-nucleus scattering with reactor antineutrinos has now been reported by the Dresden-II reactor experiment, using a germanium detector. In this paper, we present constraints on a variety of beyond the Standard Model scenarios using the new Dresden-II data. In particular, we explore the constraints imposed on neutrino non-standard interactions, neutrino magnetic moments, and several models with light scalar or light vector mediators. We also quantify the impact of their combination with COHERENT (CsI and Ar) data. In doing so, we highlight the synergies between spallation neutron source and nuclear reactor experiments regarding beyond the Standard Model searches, as well as the advantages of combining data obtained with different nuclear targets. We also study the possible signal from beyond the Standard Model scenarios due to elastic scattering off electrons (which would pass selection cuts of the COHERENT CsI and the Dresden-II experiments) and find more stringent constraints in certain parts of the parameter space than those obtained considering coherent elastic neutrino-nucleus scattering.

    hep-phJHEP(2022)·88 citations
11. 11*

    NLO QCD and EW corrections to vector-boson scattering into ${\mathrm{W}}^{+}{\mathrm{W}}^{-}$ at the LHC

    Ansgar Denner🇩🇪 · Robert Franken🇩🇪 · Timo Schmidt🇩🇪 · Christopher Schwan🇩🇪

    We present the full next-to-leading-order electroweak and QCD corrections to vector-boson scattering into a pair of off-shell opposite-sign W bosons decaying into leptons of different flavour at the LHC. We include full leading-order predictions for the irreducible background. Explicitly, we investigate the process $\mathrm{pp}\to {\mathrm{e}}^{+}{\nu }_{\mathrm{e}}{\mu }^{-}{\bar{\nu }}_{\mu }\mathrm{jj}+X$ at leading orders $O({\alpha }^6)$, $O({\alpha }_{\mathrm{s}}{\alpha }^5)$, $O({\alpha }_{\mathrm{s}}^2{\alpha }^4)$, supplemented by the loop-induced $O({\alpha }_{\mathrm{s}}^4{\alpha }^4)$ contribution, and at next-to-leading orders $O({\alpha }^7)$ and $O({\alpha }_{\mathrm{s}}{\alpha }^6)$ in two setups providing fiducial cross sections as well as differential distributions. We take full account of photon-induced next-to-leading-order contributions, which prove to be non negligible. With $-11.4\%$ and $-6.7\%$ in the two setups, the electroweak corrections are smaller than for other vector-boson-scattering processes. This can be traced back to the presence of the Higgs-boson resonance in the fiducial phase space, whose effects we analyse within an additional unphysical, but manifestly gauge-invariant setup. The QCD corrections amount to $-5.1\%$ and $-21.6\%$ in the two setups. The large size of the latter correction, compared to other vector-boson scattering processes, is explained by a very restrictive definition of its fiducial phase space.

    hep-phJHEP(2022)·29 citations
12. 12*

    Multiplicity of the doubly charmed state $T_{cc}^{+}$ in heavy-ion collisions

    Luciano M. Abreu🇧🇷 · Fernando S. Navarra🇧🇷 · Hildeson P. L. Vieira🇧🇷

    We study the evolution of the doubly charmed state $T_{cc}^{+}$ in a hot hadron gas produced in the late stage of heavy-ion collisions. We use effective Lagrangians to calculate the thermally averaged cross sections of $T_{cc}^{+}$ production in reactions such as $D^{(\ast )}{D}^{(\ast )}\to T_{cc}^{+}\pi ,T_{cc}^{+}\rho$ and its absorption in the corresponding inverse processes. We then solve the rate equation to follow the time evolution of the $T_{cc}^{+}$ multiplicity, and determine how it is affected by the considered reactions during the expansion of the hadronic matter. We compare the evolution of the $T_{cc}^{+}$ abundance treated as a hadronic $S$-wave molecule and as a tetraquark state. Our results show that the tetraquark yield increases by a factor of about 2 at freeze-out, but it is still one order of magnitude smaller than the final yield of molecules formed from hadron coalescence. Also, the results indicate that $N_{T_{cc}}$ is more affected by interactions with hadronic medium than $N_{X(3872)}$ in similar conditions. We also show that yields depend very weakly on the system size, represented by $\mathcal{N}={\left[d{N}_{ch}/d\eta (\eta <0.5)\right]}^{1/3}$.

    hep-phPRD(2022)·43 citations
13. 13*

    Reconciling the Contour-Improved and Fixed-Order Approaches for $\tau$ Hadronic Spectral Moments I: Renormalon-Free Gluon Condensate Scheme

    Miguel A. Benitez-Rathgeb🇦🇹 · Diogo Boito🇧🇷 · Andre H. Hoang🇦🇹 · Matthias Jamin🇦🇹

    We propose a simple and easy-to-implement scheme for a renormalon-free gluon condensate (GC) matrix element, which is analogous to implementations of short-distance heavy-quark mass renormalization schemes existing in the literature already for a long time. Because the scheme is based on a perturbative subtraction at the level of the matrix element, with a freely adaptable infrared factorization scale, it can be implemented with little effort for any observable where the GC is relevant. The scheme depends on the renormalon norm of the GC which has to be supplemented independently. We apply the scheme to the fixed-order (FOPT) and contour-improved (CIPT) perturbative expansions of $\tau$ hadronic spectral function moments. These expansions exhibit a long-standing discrepancy for moments used in high-precision determinations of the strong coupling in the commonly used GC scheme that is not renormalon-free. We show that the scheme is capable of resolving the FOPT-CIPT discrepancy problem. At the same time, the perturbative behaviour of the moments that previously showed bad convergence properties and for which the non-perturbative corrections from the GC are sizeable, is substantially improved. The new GC scheme may provide a powerful theoretical tool for future phenomenological applications.

    hep-phJHEP(2022)·41 citations
14. 14*

    Pion model with the Nakanishi Integral Representations

    R. M. Moita (ITA)🇧🇷 · J. P.B. C.de Melo (LFTC-UCS/UNICID)🇧🇷 · T. Frederico (ITA)🇧🇷 · W. de Paula (ITA)🇧🇷

    In the present work, we describe a model for the pion based on an analytic expression for the Bethe-Salpeter (BSA) amplitude, combined with some ingredients from Lattice QCD calculations. The running quark mass function $M(p^2)$, used here, reproduces well the results of Lattice QCD calculations. The analytical form of the running quark mass function contains a single time-like pole, which implies in time-like poles of the dressed quark propagator. Such a form allows to build the weight functions, $G_i(\gamma ,z)$, for the Nakanishi integral representation of each scalar function, ${\chi }_i(k,p)$, appearing in the decomposition of the Bethe-Salpeter amplitude in terms of Dirac operators, Such scalar amplitudes can also be used to obtain the pion valence light-front wave function.

    hep-phnucl-thRev.Mex.Fis.Suppl.(2022)·1 citation
15. 15*

    Probing light mediators and $(g-2{)}_{\mu }$ through detection of coherent elastic neutrino nucleus scattering at COHERENT

    M. Atzori Corona🇮🇹 · M. Cadeddu🇮🇹 · N. Cargioli🇮🇹 · F. Dordei🇮🇹 · C. Giunti🇮🇹 · Y.F. Li🇨🇳 · E. Picciau🇮🇹 · C. A. Ternes🇮🇹 · Y.Y. Zhang🇨🇳

    We present the constraints on the parameters of several light boson mediator models obtained from the analysis of the current data of the COHERENT CE$\nu$NS experiment. We consider a variety of vector boson mediator models: the so-called universal, the $B-L$ and other anomaly-free $U(1{)}^{\prime }$ gauge models with direct couplings of the new vector boson with neutrinos and quarks, and the anomaly-free $L_e-L_{\mu }$, $L_e-L_{\tau }$, and $L_{\mu }-L_{\tau }$ gauge models where the coupling of the new vector boson with the quarks is generated by kinetic mixing with the photon at the one-loop level. We consider also a model with a new light scalar boson mediator that is assumed, for simplicity, to have universal coupling with quarks and leptons. Since the COHERENT CE$\nu$NS data are well-fitted with the cross section predicted by the Standard Model, the analysis of the data yields constraints for the mass and coupling of the new boson mediator that depend on the charges of quarks and neutrinos in each model under consideration. We compare these constraints with the limits obtained in other experiments and with the values that can explain the muon $g-2$ anomaly in the models where the muon couples to the new boson mediator.

    hep-phJHEP(2022)·101 citations
16. 16*

    Probing Relatively Heavier Right-Handed Selectron at the CEPC, $\mathbf{FC}{\mathbf{C}}_{\mathbf{ee}}$ and ILC

    Waqas Ahmed🇨🇳 · Imtiaz Khan🇨🇳 · Tianjun Li🇨🇳 · Shabbar Raza🇵🇰 · Wenxing Zhang🇨🇳

    We employ the low energy Minimal Supersymmetric Standard Model (MSSM) to explore the parameter space associated with $Z$-pole and Higgs-pole solutions. Such parameter spaces can not only saturate the cold dark matter relic density bound within 5$\sigma$ set by the Planck 2018, but also satisfy the other standard collider mass bounds and B-physics bounds. In particular, we show that the right-handed selectron can be light. Thus, we propose a search for the relatively heavier right-handed selectron at the future lepton colliders with the center-of-mass energy $\sqrt{s}=240$ GeV and integrated luminosity 3000 $\mathrm{f}{\mathrm{b}}^{-1}$ via mono-photon channel: $e_R^{+}{e}_R^{-}\to {\tilde{\chi }}_1^0(bino)+{\tilde{\chi }}_1^0(bino)+\gamma$. We show that for the $Z$-pole case the right-handed selectron will be excluded up to 180 GeV and 210 GeV respectively at 3$\sigma$ and 2$\sigma$, while the right-handed selectron will be excluded up to 140 GeV and 180 GeV respectively at 3$\sigma$ and 2$\sigma$ in case of Higgs-pole.

    hep-phhep-exPLB(2022)·10 citations
17. 17*

    Dissociation of Pseudotensor Mesons through Critical Temperature

    A. Türkan🇹🇷 · J.Y. Süngü🇹🇷 · E. Güngör🇹🇷 · H. Reisoğlu🇹🇷 · E. Veli Veliev🇹🇷

    We have computed the masses and decay constants of isotriplet ${\pi }_2(1670)$, the isoscalar ${\eta }_2(1645)$ and ${\eta }_2(1870)$ states as the ground-state nonet of $1^1{D}_2$ case within the Thermal QCD sum rules framework. This method is applied to the spectral changes of pseudotensor mesons at high temperatures including quark, gluon, and mixed condensates up to the five dimensions. We found that their masses and decay constants are insensitive to temperature in low-temperature regions. At the near-critical temperature, we observed an exponential decrease of the masses of ${\pi }_2$, ${\eta }_2(1645)$, and ${\eta }_2(1870)$, but while the decay constant of ${\pi }_2$ is fallen, that of ${\eta }_2(1645)$ and ${\eta }_2(1870)$ is increased as a function of temperature. The modification of condensates at $T\ne 0$ is crucial to the change of considered mesons properties in a hot medium. We discuss and interpret the implications of the physical meaning of our results.

    hep-phInt.J.Theor.Phys.(2022)·2 citations
18. 18*

    The Boring Monopole

    Prateek Agrawal🇬🇧 · Michael Nee🇬🇧

    We study false vacuum decays catalysed by magnetic monopoles which act as tunnelling sites with exponentially enhanced decay rates. The field profiles describing the decay do not have the typically assumed $O(3)/O(4)$ symmetry, thus requiring an extension of the usual decay rate calculation. To numerically determine the saddle point solutions which describe the tunnelling process we use a new algorithm based on the mountain pass theorem. This method can be applied more widely to phase transitions with reduced symmetry, such as decays away from the zero and infinite temperature limits. Our results show that monopole-catalysed tunnelling can dominate over the homogeneous false vacuum decay for a wide range of parameters, significantly modify the gravitational wave signal or trigger phase transitions which would otherwise never complete. A single boring monopole in our Hubble patch may determine the lifetime of the Standard Model vacuum.

    hep-phSciPost Phys.(2022)·22 citations
19. 19*

    Kaon electromagnetic form factors in dispersion theory

    Dominik Stamen🇩🇪 · Deepti Hariharan🇩🇪 · Martin Hoferichter🇨🇭 · Bastian Kubis🇩🇪 · Peter Stoffer🇨🇭

    The electromagnetic form factors of charged and neutral kaons are strongly constrained by their low-energy singularities, in the isovector part from two-pion intermediate states and in the isoscalar contribution in terms of $\omega$ and $\varphi$ residues. The former can be predicted using the respective $\pi \pi \to \bar{K}K$ partial-wave amplitude and the pion electromagnetic form factor, while the latter parameters need to be determined from electromagnetic reactions involving kaons. We present a global analysis of time- and spacelike data that implements all of these constraints. The results enable manifold applications: kaon charge radii, elastic contributions to the kaon electromagnetic self energies and corrections to Dashen's theorem, kaon boxes in hadronic light-by-light (HLbL) scattering, and the $\varphi$ region in hadronic vacuum polarization (HVP). Our main results are: $⟨r^2{⟩}_{\text{c}}=0.359(3){\text{fm}}^2$, $⟨r^2{⟩}_{\text{n}}=-0.060(4){\text{fm}}^2$ for the charged and neutral radii, $ϵ=0.63(40)$ for the elastic contribution to the violation of Dashen's theorem, $a_{\mu }^{K\text{-box}}=-0.48(1)\times 10^{-11}$ for the charged kaon box in HLbL scattering, and $a_{\mu }^{\text{HVP}}[K^{+}{K}^{-},\le 1.05\text{GeV}]=184.5(2.0)\times 10^{-11}$, $a_{\mu }^{\text{HVP}}[K_S{K}_L,\le 1.05\text{GeV}]=118.3(1.5)\times 10^{-11}$ for the HVP integrals around the $\varphi$ resonance. The global fit to $\bar{K}K$ gives ${\bar{M}}_{\varphi }=1019.479(5)\text{MeV}$, ${\bar{\Gamma }}_{\varphi }=4.207(8)\text{MeV}$ for the $\varphi$ resonance parameters including vacuum-polarization effects.

    hep-phhep-exhep-latnucl-thEPJC(2022)·122 citations
20. 20*

    Twist-three cross-sections in deeply virtual Compton scattering

    Yuxun Guo🇺🇸 · Xiangdong Ji🇺🇸 · Brandon Kriesten🇺🇸 · Kyle Shiells🇺🇸

    We study the deeply virtual Compton scattering process with both twist-two and twist-three Compton form factors and present our cross-sections formulas with all polarization configurations. While the twist-three contributions are generally assumed to be negligible in the literature due to the kinematical suppression, we compare them with the twist-two ones at typical JLab 6 GeV and 12 GeV kinematics as well as EIC kinematics and show their kinematical suppression explicitly, justifying the leading-twist approximation made in the literature. In addition, we also estimate the twist-three Compton form factors using Wandzura-Wilczek relations and inputs of twist-two generalized parton distributions based on a reggeized spectator model. With those estimated Compton form factors, we analyze the kinematical behavior of twist-two and twist-three cross-sections in a wide range of kinematics, and discuss the optimal regions for separating the leading-twist effects from the higher-twist ones.

    hep-phnucl-exnucl-thJHEP(2022)·17 citations
21. 21*

    Relativistic hydrodynamics with spin in the presence of electromagnetic fields

    Rajeev Singh🇵🇱 · Masoud Shokri🇩🇪 · S. M. A. Tabatabaee Mehr🇮🇷

    We extend the classical phase-space distribution function to include the spin and electromagnetic fields coupling and derive the modified constitutive relations for charge current, energy-momentum tensor, and spin tensor. Because of the coupling, the new tensors receive corrections to their perfect fluid counterparts and make the background and spin fluid equations of motion communicate with each other. We investigate special cases which are relevant in high-energy heavy-ion collisions, including baryon free matter and large mass limit. Using Bjorken symmetries, we find that spin polarization increases with increasing magnetic field for an initially positive baryon chemical potential. The corrections derived in this framework may help to explain the splitting observed in Lambda hyperons spin polarization measurements.

    hep-phnucl-thNPA(2023)·45 citations
22. 22*

    Holographic Bubbles with Jecco: Expanding, Collapsing and Critical

    Yago Bea🇫🇮 · Jorge Casalderrey-Solana🇪🇸 · Thanasis Giannakopoulos🇵🇹 · Aron Jansen🇪🇸 · David Mateos🇪🇸 · Mikel Sanchez-Garitaonandia🇪🇸 · Miguel Zilhão🇵🇹

    Cosmological phase transitions can proceed via the nucleation of bubbles that subsequently expand and collide. The resulting gravitational wave spectrum depends crucially on the properties of these bubbles. We extend our previous holographic work on planar bubbles to circular bubbles in a strongly-coupled, non-Abelian, four-dimensional gauge theory. This extension brings about two new physical properties. First, the existence of a critical bubble, which we determine. Second, the bubble profile at late times exhibits a richer self-similar structure, which we verify. These results require a new 3+1 evolution code called Jecco that solves the Einstein equations in the characteristic formulation in asymptotically AdS spaces. Jecco is written in the Julia programming language and is freely available. We present an outline of the code and the tests performed to assess its robustness and performance.

    ↳ hep-thgr-qchep-phJHEP(2022)·47 citations
23. 23*

    Validation of e${}^{+}$e${}^{-}$ Pair Production Total Cross Sections for Monte Carlo Particle Transport

    Tulio Basaglia🇨🇭 · Marcia Begalli🇧🇷 · Chansoo Choi🇰🇷 · Min Cheol Han🇰🇷 · Gabriela Hoff🇮🇹 · Chan Hyeong Kim🇰🇷 · Maria Grazia Pia🇮🇹 · Paolo Saracco🇮🇹

    Several sources of total cross sections for e${}^{+}$e${}^{-}$ pair production by photon interaction with matter, used by major Monte Carlo codes for particle transport, are quantitatively evaluated with respect to experimental measurements collected from the literature. They include data libraries deriving from theoretical calculations and analytical formulae representing empirical fits to tabulations. Although most of these sources of cross sections are based on one theoretical reference, the statistical data analysis documented in the paper highlights differences in their compatibility with experiment. The cross sections collected in the 1997 version of the Evaluated Photon Data Library (EPDL) exhibit the lowest incompatibility with experiment; the paper details the validation results for all the examined cross section sources. The scarcity of experimental data does not allow the validation process to discern pair production in the field of the nucleus and in the field of atomic electrons; nevertheless, the paper documents relevant clues regarding the contribution of the latter to reproduce experimental measurements.

    ↳ physics.comp-phhep-phIEEE Trans.Nucl.Sci.(2022)·1 citation
24. 24*

    Missing large-angle correlations versus even-odd point-parity imbalance in the cosmic microwave background

    M.-A. Sanchis-Lozano🇪🇸 · F. Melia🇺🇸 · M. López-Corredoira🇪🇸 · N. Sanchis-Gual🇵🇹

    Context. The existence of a maximum correlation angle (${\theta }_{max}\gtrsim 60^{\circ }$) in the two-point angular temperature correlations of cosmic microwave background (CMB) radiation, measured by WMAP and Planck, stands in sharp contrast to the prediction of standard inflationary cosmology, in which the correlations should extend across the full sky (i.e., $180^{\circ }$). The introduction of a hard lower cutoff ($k_{min}$) in the primordial power spectrum, however, leads naturally to the existence of ${\theta }_{max}$. Among other cosmological anomalies detected in these data, an apparent dominance of odd-over-even parity multipoles has been seen in the angular power spectrum of the CMB. This feature, however, may simply be due to observational contamination in certain regions of the sky. Aims. In attempting to provide a more detailed assessment of whether this odd-over-even asymmetry is intrinsic to the CMB, we therefore proceed in this paper, first, to examine whether this odd-even parity imbalance also manifests itself in the angular correlation function and, second, to examine in detail the interplay between the presence of ${\theta }_{max}$ and this observed anomaly. Methods. We employed several parity statistics and recalculated the angular correlation function for different values of the cutoff $k_{min}$ in order to optimize the fit to the different Planck 2018 data. Results. We find a phenomenological connection between these features in the data, concluding that both must be considered together in order to optimize the theoretical fit to the Planck 2018 data. Conclusions. This outcome is independent of whether the parity imbalance is intrinsic to the CMB, but if it is, the odd-over-even asymmetry would clearly point to the emergence of new physics.

    ↳ astro-ph.COgr-qchep-phAstron.Astrophys.(2022)·13 citations
25. 25*

    Constraints on the mass and self-coupling of Ultra-Light Scalar Field Dark Matter using observational limits on galactic central mass

    Sayan Chakrabarti🇮🇳 · Bihag Dave🇮🇳 · Koushik Dutta🇮🇳 · Gaurav Goswami🇮🇳

    It is well known that Ultra-Light Dark Matter (ULDM), usually scalar fields of mass $m\sim 10^{-22}\mathrm{eV}$, can solve some of the outstanding problems of the Cold Dark Matter (CDM) paradigm. Such a scalar field could have non-negligible self-coupling $\lambda$. In this work, using the known observational upper limit on the amount of centrally concentrated dark matter in a galaxy, we arrive at the observational constraints in the $\lambda -m$ (self coupling $-$ mass) parameter space. It is found that the observational limit on the mass $m$ of the ULDM depends upon the sign and strength of the self-interactions. We demonstrate that, for $m\sim 10^{-22}\mathrm{eV}$, self-coupling values of $\mathcal{O}(10^{-96})$ (corresponding to a scattering length of $a_s\sim 10^{-82}\mathrm{m}$) can be probed using limits on the dark matter mass within 10 pc of the centre of M87 galaxy. Our analysis suggests that if Ultra Light Axions (ULAs) form all of dark matter, its mass has to be less than $\sim 6\times 10^{-23}$ eV.

    ↳ astro-ph.COgr-qchep-phJCAP(2022)·34 citations
26. 26*

    Radio Signals from Axion Star-Neutron Star Binaries

    Chris Kouvaris🇬🇷 · Tao Liu🇨🇳 · Kun-Feng Lyu🇺🇸

    Axion stars could form binaries with neutron stars. Given the extremely strong external magnetic field exhibited by individual neutron stars, there can be a substantial conversion of axions to photons in these binaries. The photon emission is doubly modulated due to the neutron star spinning and the axion star orbiting, yielding a unique discovery signal. Similar features are also generated in binaries between a neutron star and an axion-clouded black hole. Encouragingly, such binaries are found to be within the reach of ongoing and upcoming experiments (e.g., the Five hundred meter Aperture Spherical Telescope and the future Square Kilometer Array) for certain parameter regions. They thus provide a promising astronomical laboratory for detecting axions and axion dark matter.

    ↳ astro-ph.HEhep-phPRD(2024)·16 citations
27. 27*

    A duality connecting neural network and cosmological dynamics

    Sven Krippendorf🇩🇪 · Michael Spannowsky🇬🇧

    We demonstrate that the dynamics of neural networks trained with gradient descent and the dynamics of scalar fields in a flat, vacuum energy dominated Universe are structurally profoundly related. This duality provides the framework for synergies between these systems, to understand and explain neural network dynamics and new ways of simulating and describing early Universe models. Working in the continuous-time limit of neural networks, we analytically match the dynamics of the mean background and the dynamics of small perturbations around the mean field, highlighting potential differences in separate limits. We perform empirical tests of this analytic description and quantitatively show the dependence of the effective field theory parameters on hyperparameters of the neural network. As a result of this duality, the cosmological constant is matched inversely to the learning rate in the gradient descent update.

    ↳ gr-qcastro-ph.COcs.LGhep-ph+1Mach.Learn.Sci.Tech.(2022)·11 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.