Wed·Dec 7, 2022Wednesday·December 7, 2022

1. 01*

   Enhanced cosmic-ray antihelium production from dark matter annihilation through light mediators

   Yu-Chen Ding🇨🇳 · Nan Li🇨🇳 · Yu-Feng Zhou🇨🇳

   Cosmic-ray (CR) antihelium is an important probe for the indirect search of dark matter (DM) annihilation in the Galaxy. However, due to stringent constraints from the measurements of CR antiprotons and $\gamma$-rays, the flux of CR antihelium from the conventional DM direct annihilation into Standard Model final states is expected to be far below the sensitivity of the current experiments. We show that the production of antihelium can be significantly enhanced if the DM particles annihilate through light mediator particles with a mass $m_{\varphi }\approx 8$ GeV close to the antihelium production threshold. After taking into account the constraints from the AMS-02 antiproton data and the Fermi-LAT $\gamma$-ray data on the spheroidal dwarf galaxies, we find that in this scenario the CR antihelium flux can be enhanced by three orders of magnitude, which makes it within the sensitivity of the ongoing AMS-02 experiment.

   hep-phJCAP(2023)·4 citations
2. 02*

   Exploring SMEFT operators through single top-quark production associated with the Higgs boson at the LHC

   Monoranjan Guchait🇮🇳 · Arnab Roy

   The Standard Model effective field theory (SMEFT) provides a general framework to include the dynamics of the beyond standard model physics residing at a certain higher energy scale $\Lambda$. We study the top-quark production along with a Higgs boson and a jet (tHq) at the LHC experiment within the framework of the SMEFT. First, identifying the relevant sensitive dimension-6 SMEFT operators, a strategy is developed to constrain the Wilson Coefficients (WC) corresponding to these associated SMEFT operators using the latest LHC measurements, providing a complementary way to the global-fit approach. The best-fit values of these WCs are presented. Finally, we discuss the discovery potential of the signatures of those operators. We find that a discoverable excess due to SMEFT effects can be observed in the tHq process at the LHC with the center of mass energy $\sqrt{s}=13$ TeV and integrated luminosity options $\mathcal{L}=$300 $\mathrm{f}{\mathrm{b}}^{-1}$ and 3000 $\mathrm{f}{\mathrm{b}}^{-1}$.

   hep-phPoS(2022)·0 citations
3. 03*

   Understanding the nature of $\Omega (2012)$ in a coupled-channel approach

   Qi-Fang Lü🇨🇳 · Hideko Nagahiro🇯🇵 · Atsushi Hosaka🇯🇵

   We perform a systematic analysis of the mass and strong decays of the $\Omega (2012)$ resonance in a coupled-channel approach of a bare three-quark state and a composite meson-baryon state. Besides the coupling of the bare state and ${\Xi }^{\ast }\bar{K}$ channel, the effective meson-baryon interactions are also included. We find a pole with mass of $2008$ MeV by solving the Bethe-Salpeter equation. The calculated decay widths and its ratios of branching fractions ${\mathcal{R}}_{\Xi \bar{K}}^{\Xi \pi \bar{K}}$ agree well with the new experimental measurement by Belle Collaboration. Our results suggest that both three-quark core and ${\Xi }^{\ast }\bar{K}$ channel are essential for the description of the $\Omega (2012)$ resonance. We expect that present calculations can help us to better understand the nature of $\Omega (2012)$ resonance.

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

   Effect of anomalous magnetic moment on the chiral transition at zero temperature in a strong magnetic field

   Rui He🇨🇳 · Xin-Jian Wen🇨🇳

   The effect of the anomalous magnetic moment (AMM) on the chiral restoration is investigated at zero temperature in the strong magnetic fields with the vacuum magnetic regularization scheme. It is shown that the chiral restoration diagram sensitively depends on the AMM in the ultrastrong magnetic fields. In our work, the parameterization of AMM is employed as proportional to the square of the chiral condensate. The critical chemical potential is found to decrease linearly by the increasing coefficient in the AMM scale. At a smaller scale of the AMM, the critical chemical potential could go down and then grow up as the magnetic field increases. But at a larger scale, the magnetic catalysis on the critical chemical potential would not happen anymore.

   hep-phPRD(2022)·10 citations
5. 05*

   Testing axion couplings to leptons in $Z$ decays at future $e^{+}{e}^{-}$ colliders

   Lorenzo Calibbi🇨🇳 · Zijie Huang🇨🇳 · Shaoyang Qin🇨🇳 · Yiming Yang🇨🇳 · Xiaoyue Yin🇨🇳

   We study the possibility of probing the existence of a light, invisible, axion-like particle (ALP) $a$ in leptonic decays of the $Z$ boson at the proposed high-energy $e^{+}{e}^{-}$ colliders, CEPC and FCC-ee. Both projects plan to run at the $Z$ pole, collecting $10^{12}-10^{13}$ visible $Z$ decays. We show that, searching for the emission of an invisible ALP from leptons in leptonic $Z$ decays, this enormous statistics could allow to constrain the ALP couplings to leptons at an unprecedented level for laboratory experiments. In particular, within a Monte Carlo simulation framework, we estimate that CEPC/FCC-ee can be sensitive to the coupling of an invisible ALP to muons up to $f_a/C_{\mu \mu }^A\approx 1$ TeV - where $f_a$ is the ALP decay constant - corresponding to $\mathrm{BR}(Z\to {\mu }^{+}{\mu }^{-}a)\approx 3\times 10^{-11}$.

   hep-phhep-exPRD(2023)·26 citations
6. 06*

   Partial wave effects in the heavy quarkonium radiative electromagnetic decays

   Su-Yan Pei🇨🇳 · Wei Li🇨🇳 · Ting-Ting Liu🇨🇳 · Meng Han🇨🇳 · Guo-Li Wang🇨🇳 · Tianhong Wang🇨🇳

   In a previous paper \cite{Bc}, it was pointed out that the wave functions of all particles are not pure waves, besides the main partial waves, they all contain {other partial waves}. It is very interesting to know what role these different partial waves play in particle transitions. Therefore, by using the Bethe-Salpeter equation method, we study the radiative electromagnetic decays $\psi \to \gamma {\chi }_{{}_{cJ}}$ and ${\rm Y}\to \gamma {\chi }_{{}_{bJ}}$ ($J=0,1,2$). We find that for the $S$ and $P$ wave dominated states, like the $\psi (2S)$, ${\rm Y}(2S)$, ${\chi }_{{}_{cJ}}(1P)$, and ${\chi }_{{}_{bJ}}(1P)$ etc., the dominant $S$ and $P$ waves provide main and nonrelativistic contrition to the decays; other partial waves mainly contribute to the relativistic correction. For the states like the $\psi (1D)$, ${\rm Y}(2D)$, ${\chi }_{c2}(1F)$, and ${\chi }_{b2}(1F)$ etc., they are the $S-P-D$ mixing state dominated by $D$ wave or the $P-D-F$ mixing state dominated by $F$ wave. Large decay widths are found in the transitions $\psi (2D)\to {\chi }_{c2}(1F)$, ${\rm Y}(1D)\to {\chi }_{bJ}(1P)$, and ${\rm Y}(2D)\to {\chi }_{bJ}(2P)$ etc., which may be helpful to study the missing states ${\chi }_{c2}(1F)$, ${\rm Y}(1D)$, and ${\rm Y}(2D)$.

   hep-phhep-exPRD(2023)·9 citations
7. 07*

   Determination of HQET nonperturbative matrix elements with renormalon subtraction using Fourier transform

   Hiromasa Takaura🇯🇵

   As higher order perturbative series are available, it is becoming necessary to include nonperturbative effects in QCD calculations using the OPE. In order to systematically determine nonperturbative effects and to incorporate them into theoretical calculations, the renormalon problem should be resolved. We use a renormalon subtraction method utilizing Fourier transform to determine nonperturbative matrix elements of HQET, $\bar{\Lambda }$ and ${\mu }_{\pi }^2$. This is the first determination performed with subtraction of the $u=1$ renormalon.

   hep-phEPJ Web Conf.(2022)·1 citation
8. 08*

   Higher Twists

   Vladimir M. Braun🇩🇪

   Higher twist corrections refer to a certain class of contributions to hard processes in strong interactions that are suppressed by a power of the hard scale. This is a very broad field of research which is becoming more and more important as the accuracy of the available experimental data increases. I give an overview of some basic relevant theory concepts and technical developments, and briefly discuss a few phenomenological applications.

   hep-phEPJ Web Conf.(2022)·16 citations
9. 09*

   Next-to-Soft Virtual Resummation for QCD Observables

   A. H. Ajjath · Pooja Mukherjee🇩🇪 · V. Ravindran🇮🇳 · Aparna Sankar🇩🇪 · Surabhi Tiwari🇮🇳

   We present a framework for resumming the contributions from soft-virtual and next-to-soft virtual (NSV) logarithms. Numerical impact for these resummed predictions are discussed for the inclusive cross section for Drell-Yan di-lepton process up to next-to-next-to leading logarithmic accuracy, restricting to only diagonal partonic channels.

   hep-phActa Phys.Polon.Supp.(2023)·0 citations
10. 10*

    A Large Muon EDM from Dark Matter

    Kim Siang Khaw🇨🇳 · Yuichiro Nakai🇨🇳 · Ryosuke Sato🇯🇵 · Yoshihiro Shigekami🇨🇳 · Zhihao Zhang🇨🇳

    We explore a model of dark matter (DM) that can explain the reported discrepancy in the muon anomalous magnetic moment and predict a large electric dipole moment (EDM) of the muon. The model contains a DM fermion and new scalars whose exclusive interactions with the muon radiatively generate the observed muon mass. Constraints from DM direct and indirect detection experiments as well as collider searches are safely evaded. The model parameter space that gives the observed DM abundance and explains the muon $g-2$ anomaly leads to the muon EDM of $d_{\mu }\simeq (4$-$5)\times 10^{-22}e\mathrm{cm}$ that can be probed by the projected PSI muEDM experiment. Another viable parameter space even achieves $d_{\mu }=\mathcal{O}(10^{-21})e\mathrm{cm}$ reachable by the ongoing Fermilab Muon $g-2$ experiment and the future J-PARC Muon $g-2$/EDM experiment.

    hep-phastro-ph.COhep-exJHEP(2023)·11 citations
11. 11*

    Investigating $B_c$ semileptonic decays

    Francesco Loparco🇮🇹

    I present analyses of semileptonic $B_c$ decays. I first discuss the decays induced by $c\to \{s,d\}$ transitions, in particular $B_c\to B_a\bar{\ell }{\nu }_{\ell }$ and $B_c\to B_a^{\ast }(\to B_a\gamma )\bar{\ell }{\nu }_{\ell }$ decays, with $a=\{s,d\}$ and $\ell =\{e,\mu \}$, in the Standard Model and in the extension based on the low-energy Hamiltonian comprising the full set of $D=6$ semileptonic $c\to s,d$ operators with left-handed neutrinos.\\ Moreover, I consider $b\to c$ modes, with particular focus on the determination of the form factors parametrizing the $B_c\to J/\psi ,{\eta }_c$ matrix elements of the operators in a generalized low-energy $b\to c$ semileptonic Hamiltonian. In this case I consider an expansion in nonrelativistic \qcd\ together with an expansion in the inverse heavy-quark mass which allows the form factors to be expressed in terms of universal functions in a selected kinematical range.\\ The Heavy Quark Spin Symmetry is used for both analyses. In the first case, it allows the relevant hadronic matrix elements to be related and the lattice \qcd\ results on $B_c$ form factors to be exploited. Optimized observables are selected, and correlations among them is studied to identify the effects of the various operators in the extended low-energy Hamiltonian. In the second one, using as an input the lattice \qcd\ results for the $B_c\to J/\psi$ matrix element of the Standard Model operator, it is possible to obtain information on other form factors. The extrapolation to the full kinematical range is also presented.

    hep-phhep-exhep-latPoS(2022)·0 citations
12. 12*

    LHC EFT WG Note: Precision matching of microscopic physics to the Standard Model Effective Field Theory (SMEFT)

    Sally Dawson🇺🇸 · Admir Greljo🇨🇭 · Kristin Lohwasser🇬🇧 · Jason Aebischer🇨🇭 · Supratim Das Bakshi🇪🇸 · Adrián Carmona🇪🇸 · Joydeep Chakrabortty🇮🇳 · Timothy Cohen🇺🇸 · Juan Carlos Criado🇬🇧 · Javier Fuentes-Martín🇪🇸 · Achilleas Lazopoulos🇨🇭 · Xiaochuan Lu🇺🇸 and 7 other authors

    This note gives an overview of the tools for the precision matching of ultraviolet theories to the Standard Model effective field theory (SMEFT) at the tree level and one loop. Several semi- and fully automated codes are presented, as well as some supplementary codes for the basis conversion and the subsequent running and matching at low energies. A suggestion to collect information for cross-validations of current and future codes is made.

    hep-phhep-exhep-th16 citations
13. 13*

    Matter effect in presence of a sterile neutrino and resolution of the octant degeneracy using a liquid argon detector

    Animesh Chatterjee🇮🇳 · Srubabati Goswami🇮🇳 · Supriya Pan🇮🇳

    Results from the experiments like LSND, and MiniBooNE hint towards the possible presence of an extra eV scale sterile neutrino. The addition of such a neutrino will significantly impact the standard three flavour neutrino oscillations; in particular, it can give rise to additional degeneracies due to new sterile parameters. In our work, we investigate how the sensitivity to determine the octant of the neutrino mixing angle ${\theta }_{23}$ is affected by introducing a sterile neutrino to the standard neutrino oscillation framework. We compute the oscillation probabilities in presence of a sterile neutrino, analytically, using the approximation that ${\Delta }_{21}$, the smallest mass squared difference, is zero. We use these probabilities to understand the degeneracies analytically at different baselines. We present our results of the sensitivity to octant of ${\theta }_{23}$ for beam neutrinos using a liquid argon time projection chamber (LArTPC). We also obtain octant sensitivity using atmospheric neutrinos using the same LArTPC detector without any charge identification capability. In addition, we include the charge tagging capability of muon capture in argon which allows one to differentiate between muon neutrino and antineutrino events. The combined sensitivity of beam and atmospheric neutrinos in a similar experimental setup is also delineated. We observe that by combining simulated data from the beam and atmospheric neutrinos (including charge-id for muons), the sensitivity to the octant of ${\theta }_{23}$ for true values of ${\theta }_{23}=41^{\circ }(49^{\circ })$ exceeds $4\sigma (3\sigma )$ for more than $50\%$ values of true ${\delta }_{13}$.

    hep-phhep-exPRD(2023)·9 citations
14. 14*

    Next-to-Leading Order virtual correction to Higgs-induced DIS

    Anna Rinaudo🇮🇹

    We calculate the Next-to-Leading Order (NLO) virtual correction to the Higgs-induced DIS coefficient function in the infinite top-mass limit. Since we want to use this result in the framework of kt-factorization to resum small-x logarithms up to Next-to-Leading-Logarithm (NLL), we work in light-cone gauge and we keep the incoming gluon off-shell. This choice raises many challenging points like the presence of spurious singularities and a different definition for the UV-counterterms. This calculation is a necessary ingredient for the coefficient function that will be used to resum up to NLL small-x logarithms for this process.

    hep-phActa Phys.Polon.Supp.(2023)·2 citations
15. 15*

    Semileptonic decays of doubly charmed baryons with ${\Xi }_c-{\Xi }_c^{\prime }$ mixing

    Chao-Qiang Geng🇨🇳 · Xian-Nan Jin🇨🇳 · Chia-Wei Liu🇨🇳 · Xiao Yu🇨🇳 · Ao-Wen Zhou🇨🇳

    We study the ${\Xi }_c-{\Xi }_c^{\prime }$ mixing effects in the semileptonic decays the doubly charm baryons of ${\Xi }_{cc}$. We focus on the ratio of $\mathcal{R}({\theta }_c)\equiv \mathcal{B}({\Xi }_{cc}\to {\Xi }_c^{\prime }{e}^{+}{\nu }_e)/\mathcal{B}({\Xi }_{cc}\to {\Xi }_c{e}^{+}{\nu }_e)$ and find that $(\mathcal{R}({\theta }_0),\mathcal{R}(-{\theta }_0))=(0.46\pm 0.01,7.33\pm 0.23)$ with ${\theta }_0=0.137\pi$, which are in sharp contrast to $\mathcal{R}(0)=2.15\pm 0.11$ without the mixing. The ratio is enhanced~(suppressed) by a factor of four for a negative~(positive) ${\theta }_c$. In addition, the polarization asymmetries of ${\Xi }_c^{(\prime )}$ are found to be $\alpha (-{\theta }_0)=0.32(-0.76)$ and $\alpha ({\theta }_0)=-0.82(-0.38)$. As $\mathcal{R}$ and $\alpha$ are highly sensitive to ${\theta }_c$ and unaffected by the $W$-exchange contributions, they provide excellent opportunities to determine ${\theta }_c$ in the ongoing experiments.

    hep-phhep-exPLB(2023)·12 citations
16. 16*

    Time-reversal asymmetries in ${\Lambda }_b\to \Lambda (\to p{\pi }^{-}){\ell }^{+}{\ell }^{-}$

    Chao-Qiang Geng🇨🇳 · Chia-Wei Liu🇨🇳 · Zheng-Yi Wei🇨🇳

    We study the decays of ${\Lambda }_b\to \Lambda (\to p{\pi }^{-}){\ell }^{+}{\ell }^{-}$ with $\ell =(e,\mu ,\tau )$. In particular, we examine the full angular distributions with polarized ${\Lambda }_b$ and identify the time-reversal asymmetries or T-odd observables. By using the homogeneous bag model, we find that the decay branching fractions of ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$ are $(9.1\pm 2.5,7.9\pm 1.8,2.1\pm 0.2)\times 10^{-7}$ for $\ell =(e,\mu ,\tau )$, respectively. In addition, we obtain that $A_{FB}^{\ell }=-0.369\pm 0.007$ and $A_{FB}^h=-0.333\pm 0.004$, averaged in the range of $15\le q^2\le 20{\text{GeV}}^2$. These results are well consistent with the current experimental data. We also explore the T-odd observables in ${\Lambda }_b\to \Lambda (\to p{\pi }^{-}){\mu }^{+}{\mu }^{-}$, which are sensitive to new physics~(NP). Explicitly, we illustrate that the current experimental measurement from one of the T-odd observables favors the existence of NP, such as the extra $Z$-boson model.

    hep-phhep-exCPC(2024)·3 citations
17. 17*

    The decays of the fully open flavor state $T_{c\bar{s}0}^0$ in a $D^{\ast }{K}^{\ast }$ molecule scenario

    Zi-Li Yue🇨🇳 · Cheng-Jian Xiao🇨🇳 · Dian-Yong Chen🇨🇳

    Inspired by the recent observations of $T_{c\bar{s}0}^{0/++}$ in the the processes $B^0\to {\bar{D}}^0{D}_s^{+}{\pi }^{-}$ and $B^{+}\to D^{-}{D}_s^{+}{\pi }^{+}$ by LHCb Collaboration, we investigate the decay properties of the $T_{c\bar{s}0}^0$ in a $D^{\ast }{K}^{\ast }$ molecule scenario, and the widths of $T_{c\bar{s}0}^0\to D^0{K}^0$, $D_s^{+}{\pi }^{-}$, $D_s^{\ast +}{\rho }^{-}$, $D_{s1}^{(\prime )+}{\pi }^{-}$, and $D^{\ast 0}(D\pi {)}^0$ are estimated. Our estimations indicate that the width of $T_{c\bar{s}0}^0\to D_s^{+}{\pi }^{-}$ is sizable to be observed and the dominant decay mode of $T_{c\bar{s}0}^0$ is $D^0{K}^0$. Considering the isospin symmetry, we proposed to search $T_{c\bar{s}0}(2900{)}^{++}$ in the $D^{+}{K}^{+}$ invariant mass distributions of the process $B^{+}\to D^{+}{D}^{-}{K}^{+}$, where some preliminary experimental hints have been observed by LHCb Collaboration.

    hep-phhep-exPRD(2023)·33 citations
18. 18*

    Observing axions through photon ring dimming of black holes

    Kimihiro Nomura🇯🇵 · Kaishu Saito🇯🇵 · Jiro Soda🇯🇵

    It is known that magnetic fields exist near black holes and photons can go around black holes due to strong gravity. Utilizing these facts, we can probe hypothetical pseudoscalar particles, so-called axions. In fact, photons can be converted into axions when they propagate in a magnetic field. The conversion of such photons into axions leads to a dimming of the photon ring around the black hole shadow. We show that photon ring dimming can occur efficiently for supermassive black holes. Remarkably, it turns out that the maximal dimming rate of the photon ring is 25%. In the case of M87*, the dimming of 10% will be observed in the X-ray and gamma-ray bands if the angular resolution of $10^{-5}$ arcsec is achieved. The frequency band and the magnitude of the dimming depend on the axion-photon coupling and axion mass. Hence, the distorted spectrum of the photon ring provides a novel tool for detecting axions.

    hep-phastro-ph.COgr-qchep-thPRD(2023)·9 citations
19. 19*

    Gravitational corrections to electroweak vacuum decay: metric vs. Palatini

    Ioannis D. Gialamas🇪🇪 · Alexandros Karam🇪🇪 · Thomas D. Pappas🇨🇿

    We consider the standard Einstein-Hilbert-Higgs action where the Higgs field couples nonminimally with gravity via the term $\xi h^2\mathcal{R}$, and investigate the stability of the electroweak vacuum in the presence of gravitational corrections in both the metric and Palatini formulations of gravity. In order to identify the differences between the two formalisms analytically, we follow a perturbative approach in which the gravitational corrections are taken into consideration via a leading order expansion in the gravitational coupling constant. Our analysis shows that in the Palatini formalism, the well-known effect of gravity suppressing the vacuum decay probability, becomes milder in comparison with the metric case for any value of the nonminimal coupling $\xi$. Furthermore, we have found that in the Palatini formalism, the positivity of the gravitational corrections, which is a necessary requirement for the unitarity of the theory, entails the lower bound $\xi >-1/12$.

    hep-phgr-qchep-thPLB(2023)·19 citations
20. 20*

    Multipartonic cascades in expanding media

    Souvik Priyam Adhya🇵🇱 · Carlos A. Salgado🇪🇸 · Martin Spousta🇨🇿 · Konrad Tywoniuk🇳🇴

    In this work, we introduce both gluon and quark degrees of freedom for describing the partonic cascades inside the medium. We present numerical solutions for the set of coupled evolution equations with splitting kernels calculated for the static, exponential and Bjorken expanding media to arrive at medium-modified parton spectra for quark and gluon initiated jets respectively. We discuss novel scaling features of the partonic spectra between different types of media. Next, we study the inclusive jet $R_{AA}$ by including phenomenologically driven combinations of quark and gluon fractions inside a jet. In addition, we have also studied the effect of the nPDF as well as vacuum like emissions on the jet $R_{AA}$. Differences among the estimated values of quenching parameter for different types of medium expansions are noted. Next, the impact of the expansion of the medium on the rapidity dependence of the jet $R_{AA}$ as well as jet $v_2$ are studied in detail. Finally, we present qualitative results comparing the sensitivity of the time for the onset of the quenching for the Bjorken profile on these observables. All the quantities calculated are compared with the recent ATLAS data.

    hep-phActa Phys.Polon.Supp.(2023)·1 citation
21. 21*

    Phenomenological model for the $\gamma \gamma \to {\pi }^{+}{\pi }^{-}{\pi }^0$ reaction

    Xiu-Lei Ren🇩🇪 · Igor Danilkin🇩🇪 · Marc Vanderhaeghen🇩🇪

    We present a phenomenological model for the $\gamma \gamma \to {\pi }^{+}{\pi }^{-}{\pi }^0$ reaction by including the production mechanism of the $a_2(1320)$ resonance, as well as the contributions from the $\sigma /f_0(500){\pi }^0$ and $f_2(1270){\pi }^0$ production channels. Furthermore, the $\gamma \gamma \to {\rho }^{\pm }{\pi }^{\mp }\to {\pi }^{+}{\pi }^{-}{\pi }^0$ channel, which is essential for a description in the low-energy region, is investigated carefully by introducing the complete set of gauge invariant and Lorentz-covariant tensors for the $\gamma \gamma \to {\rho }^{\pm }{\pi }^{\mp }$ subprocess. The full amplitude is constructed to yield a correct high-energy Regge behavior. Within our model, we achieve a very reasonable description of ARGUS and L3 data of the total cross section, as well as of the ${\pi }^{\pm }{\pi }^0$ and ${\pi }^{+}{\pi }^{-}$ invariant mass distributions. We also predict the invariant mass distributions in the $\gamma \gamma$ center-of-mass energy range from $0.8$ GeV to $2.0$ GeV, which will be studied by the forthcoming data of the BESIII collaboration.

    hep-phnucl-thPRD(2023)·6 citations
22. 22*

    Pair Production in Circularly Polarized Waves

    Christian Kohlfürst🇩🇪

    We study electron-positron pair production within two counter-propagating, circularly polarized electromagnetic fields through the Wigner formalism. We numerically generate high-resolution momentum maps to perform a detailed spectroscopic analysis. We identify signatures of polarization and kinematics of the incident fields in the final positron distribution and, on this basis, provide an intuitive picture of helicity transfer in multiphoton pair production.

    hep-phhep-thPRD(2024)·19 citations
23. 23*

    Renormalization of the Standard Model Effective Field Theory from Geometry

    Andreas Helset🇺🇸 · Elizabeth E. Jenkins🇺🇸 · Aneesh V. Manohar🇺🇸

    $S$-matrix elements are invariant under field redefinitions of the Lagrangian. They are determined by geometric quantities such as the curvature of the field-space manifold of scalar and gauge fields. We present a formalism where scalar and gauge fields are treated together, with a metric on the combined space of both types of fields. Scalar and gauge scattering amplitudes are given by the Riemann curvature $R_{ijkl}$ of this combined space, with indices $i,j,k,l$ chosen to be scalar or gauge indices depending on the type of external particle. One-loop divergences can also be computed in terms of geometric invariants of the combined space, which greatly simplifies the computation of renormalization group equations. We apply our formalism to the Standard Model Effective Field Theory (SMEFT), and compute the renormalization group equations for even-parity bosonic operators to mass dimension eight.

    hep-phhep-thJHEP(2023)·66 citations
24. 24*

    Double insertions of SMEFT operators in gluon fusion Higgs boson production

    Konstantin Asteriadis🇺🇸 · Sally Dawson🇺🇸 · Duarte Fontes🇺🇸

    Deviations from the Standard Model (SM) can be parameterized in terms of the SM effective field theory (SMEFT), which is typically truncated at dimension-6. Including higher dimension operators -- as well as considering simultaneous insertions of multiple dimension-6 operators -- may be necessary in some processes, in order to correctly capture the properties of the underlying UV theory. As a step towards clarifying this in the Higgs boson production in gluon fusion process, we study double insertions of dimension-6 operators in the 1-loop virtual amplitude. We present needed Feynman rules up to $\mathcal{O}(1/{\Lambda }^4)$ and we numerically study the impact of various approximations to the $\mathcal{O}(1/{\Lambda }^4)$ expansion.

    hep-phPRD(2023)·29 citations
25. 25*

    Threshold resummation for the production of four top quarks at the LHC

    Melissa van Beekveld🇬🇧 · Anna Kulesza🇩🇪 · Laura Moreno Valero🇩🇪

    We compute the total cross section for $t\bar{t}t\bar{t}$ production at next-to-leading logarithmic (NLL${}^{\prime }$) accuracy. This is the first time resummation is performed for a hadron-collider process with four colored particles in the final state. The calculation is matched to the next-to-leading order strong and electroweak corrections. The NLL${}^{\prime }$ corrections enhance the total production rate by 26\%. The size of the theoretical error due to scale variation is reduced by close to a factor of two, bringing the theoretical error significantly below the current experimental uncertainty of the measurement.

    hep-phPRL(2023)·79 citations
26. 26*

    Suppression exponent for multiparticle production in $\lambda {\varphi }^4$ theory

    S.V. Demidov🇷🇺 · B.R. Farkhtdinov🇷🇺 · D.G. Levkov🇷🇺

    We compute the probability of producing $n$ particles from few colliding particles in the unbroken $(3+1)$-dimensional $\lambda {\varphi }^4$ theory. To this end we numerically implement semiclassical method of singular solutions which works at $n\gg 1$ in the weakly coupled regime $\lambda \ll 1$. For the first time, we obtain reliable results in the region of exceptionally large final state multiplicities $n\gg {\lambda }^{-1}$ where the probability decreases exponentially with $n$, $\mathcal{P}(\text{mbox}few\to n)\sim \exp \{f_{\infty }(\epsilon )n\}$, and its slope $f_{\infty }<0$ depends on the mean kinetic energy $\epsilon$ of produced particles. In the opposite case $n\ll {\lambda }^{-1}$ our data match well-known tree-level result, and they interpolate between the two limits at $n\sim {\lambda }^{-1}$. Overall, this proves exponential suppression of the multiparticle production probability at $n\gg 1$ and arbitrary $\epsilon$ in the unbroken theory. Using numerical solutions, we critically analyze the mechanism for multiple Higgs boson production suggested in the literature. Application of our technique to the scalar theory with spontaneously broken symmetry can eradicate (or confirm) it in the nearest future.

    hep-phhep-thJHEP(2023)·6 citations
27. 27*

    Constraining higher-spin S-matrices

    Tung Tran🇧🇪

    There are various no-go theorems that tightly constrain the existence of local higher-spin theories with non-trivial S-matrix in flat space. Due to the existence of higher-spin Yang-Mills theory with non-trivial scattering amplitudes, it makes sense to revisit Weinberg's soft theorem - a direct consequence of the Lorentz invariance of the S-matrix that does not take advantage of unitarity and parity invariance. By working with the chiral representation - a representation originated from twistor theory, we show that Weinberg's soft theorem can be evaded and non-trivial higher-spin S-matrix is possible. In particular, we show that Weinberg's soft theorem is more closely related to the number of derivatives in the interactions rather than spins. We also observe that all constraints imposed by gauge invariance of the S-matrix are accompanied by polynomials in the soft momentum of the emitted particle where the zeroth order in the soft momentum is charge conservation law.

    ↳ hep-thhep-phJHEP(2023)·18 citations
28. 28*

    Constructing Operator Basis in Supersymmetry: A Hilbert Series Approach

    Antonio Delgado🇺🇸 · Adam Martin🇺🇸 · Runqing Wang🇺🇸

    In this paper we introduce a Hilbert series approach to build the operator basis for a N = 1 supersymmetry theory with chiral superfields. We give explicitly the form of the corrections that remove redundancies due to the equations of motion and integration by parts. In addition, we derive the maps between the correction spaces. This technique allows us to calculate the number of independent operators involving chiral and antichiral superfields to arbitrarily high mass dimension. Using this method, we give several illustrative examples.

    ↳ hep-thhep-phJHEP(2023)·10 citations
29. 29*

    Model-independent determination of nuclear weak form factors and implications for Standard Model precision tests

    Chien-Yeah Seng🇺🇸

    We analyze the recoil corrections in superallowed beta decays of $T=1$, $J^P=0^{+}$ nuclei by fixing the mean square charge weak radius model-independently using the data of multiple charge radii across the nuclear isotriplet. By comparing to model estimations, we argue that the existing theory uncertainty in the statistical rate function $f$ might have been substantially underestimated. We discuss the implications of our proposed strategy for precision tests of Standard Model, including a potential alleviation of the first-row CKM unitarity deficit, and motivate new experiments for charge radii measurements.

    ↳ nucl-thhep-exhep-phnucl-exPRL(2023)·26 citations
30. 30*

    On the Proof of Chiral Symmetry Breaking from Anomaly Matching in QCD-like Theories

    Luca Ciambriello🇮🇹 · Roberto Contino🇮🇹 · Andrea Luzio🇮🇹 · Marcello Romano🇫🇷 · Ling-Xiao Xu🇮🇹

    We critically reconsider the argument based on 't Hooft anomaly matching that aims at proving chiral symmetry breaking in confining four-dimensional QCD-like theories with $N_c>2$ colors and $N_f$ flavors. The main line of reasoning relies on a property of the solutions of the anomaly matching and persistent mass equations called $N_f$-independence. In previous works, the validity of $N_f$-independence was assumed based on qualitative arguments, but it was never proven rigorously. We provide a detailed proof and clarify under which (dynamical) conditions it holds. Our results are valid for a generic spectrum of massless composite fermions including baryons and exotics.

    ↳ hep-thhep-lathep-phPRD(2024)·10 citations
31. 31*

    Spontaneous Symmetry Breaking and the Cosmological Constant

    J. Gamboa🇨🇱 · J. Lopez-Sarrion🇪🇸 · F. Mendez🇨🇱 · N. Tapia-Arellano🇺🇸

    An approach that allows studying the relationship between the neutralization of the cosmological constant and instantons for cosmology coupled to antisymmetric fields is proposed. Using suitable variables, the Lagrangian leading to the FRW equations can be written analogously to a Ginzburg-Landau theory and we show how spontaneous symmetry breaking appears. The approach leads to three possible solutions, if we denote ${\Lambda }_1$ and ${\Lambda }_2$ as the cosmological constants that come from gravity (${\Lambda }_1$) and antisymmetric fields (${\Lambda }_2$), then the solutions, a) $|{\Lambda }_2|>|{\Lambda }_1|$ is consistent with a very small but non-zero ${\Lambda }_1$, b) $|{\Lambda }_2|<|{\Lambda }_1|$, then ${\Lambda }_1$ is observationally ruled out and, c) $|{\Lambda }_2|=|{\Lambda }_1|$ is a solution with finite action and instantons restoring the symmetry $\phi \to -\phi$. The third solution is also consistent with neutralization of the cosmological constant in four dimensions.

    ↳ hep-thgr-qchep-phMod.Phys.Lett.A(2023)·2 citations
32. 32*

    Event-by-event investigation of the two-particle source function in $\sqrt{s_{{}_{\text{NN}}}}=2.76$ TeV PbPb collisions with EPOS

    Balázs Kórodi🇭🇺 · Dániel Kincses🇭🇺 · Máté Csanád🇭🇺

    The investigation of the two-particle source function in lead-lead collisions simulated by the EPOS model at a center of mass energy per nucleon pair of $\sqrt{s_{{}_{\text{NN}}}}=2.76$ TeV is presented. The two-particle source functions are reconstructed directly on an event-by-event basis for pions, kaons and protons separately, using the final stage of EPOS. A Lévy source shape is observed for all three particle species in the individual events, deviating significantly from a Gaussian shape. The source parameters are extracted as functions of collision centrality and pair average transverse mass ($m_{\text{T}}$). The Lévy exponent is found to be ordered accordingly to particle mass. The Lévy scale parameter is found to scale for all particle species with $m_{\text{T}}$ according to Gaussian hydrodynamical predictions; however, there is no $m_{\text{T}}$-scaling found across these species. In case of pions, the effects of the decay products and hadronic rescattering are also investigated. The Lévy exponent is decreased when decay products are also included in the analysis. Without hadronic rescattering and decay products, the source shape is close to a Gaussian.

    ↳ nucl-thhep-phnucl-exPLB(2023)·23 citations
33. 33*

    Constraining decaying dark matter with the effective field theory of large-scale structure

    Théo Simon🇫🇷

    I present the first constraints on decaying cold dark matter (DCDM) models thanks to the effective field theory of large-scale structure (EFTofLSS) applied to BOSS-DR12 data. I consider two phenomenological models of DCDM: i) a model where a fraction $f_{\mathrm{dcdm}}$ of cold dark matter (CDM) decays into dark radiation (DR) with a lifetime $\tau$; ii) a model (recently suggested as a potential resolution to the $S_8$ tension) where all the CDM decays with a lifetime $\tau$ into DR and a massive warm dark matter (WDM) particle, with a fraction $\epsilon$ of the CDM rest mass energy transferred to the DR. I discuss the implications of the EFTofLSS constraints for the DCDM model suggested to resolve the $S_8$ tension.

    ↳ astro-ph.COhep-ph3 citations
34. 34*

    Lattice QCD at non-zero temperature and density

    Frithjof Karsch🇩🇪

    Soon after the formulation of Quantum Chromodynamics in 1972 its regularization on Euclidean space-time lattices had been introduced by Kenneth Wilson. This paved ground for numerical studies of non-perturbative aspects of QCD, first shown by Michael Creutz. Ever since these first lattice QCD calculations the exploration of the QCD phase diagram and the thermodynamics of strong-interaction matter at non-zero temperature and density was pursued vigorously. In this brief review I try to highlight some of the results on QCD thermodynamics obtain during the last 42 years through lattice QCD calculations.

    ↳ hep-lathep-phhep-th7 citations
35. 35*

    Stringent Pulsar Timing Bounds on Light Scalar Couplings to Matter

    David Benisty🇬🇧 · Philippe Brax🇫🇷 · Anne-Christine Davis🇬🇧

    Pulsar Timing constraints on scalar-tensor theories with conformal and disformal couplings to matter are discussed. Reducing the dynamics to the motion in the centre of mass frame and using the mean anomaly parametrisation, we find the first post-Newtonian corrections induced by the conformal and disformal interactions in the form of a generalized quasi-Keplerian solution. We also derive the radiation reaction force due to scalar radiation and the corresponding Post-Keplerian Parameters (PKP). We use different pulsar time of arrival (TOA) data sets to probe the scalar corrections to the PKP. In particular, we focus on systems with large orbital frequencies as the contributions to the PKP terms induced by the disformal coupling are sensitive to higher frequencies. We find that the most constraining { {pulsar timings}} are PSR B1913+16 and the double pulsar PSR J0737-3039A/B, being {{of the order of}} the Cassini bound on the conformal coupling obtained from the Shapiro effect in the solar system. { {The combined constraints using other pulsar timings give an upper bound on the conformal coupling ${\beta }^2<2.33\cdot 10^{-5}$ and a lower bound on the disformal coupling scale of $\Lambda \ge 1.12\mathrm{MeV}$ which is comparable to the Cassini bound and to the GW-170817 constraints respectively}}. Future measurements for pulsar timing with black hole companions are also discussed.

    ↳ gr-qcastro-ph.HEastro-ph.SRhep-ph+1PRD(2023)·22 citations
36. 36*

    Thermal phase transitions in rotating QCD with dynamical quarks

    V. V. Braguta🇷🇺 · A. Yu. Kotov🇷🇺 · A. A. Roenko🇷🇺 · D. A. Sychev🇷🇺

    Relativistic rotation causes a change of QCD critical temperatures. Various phenomenological and effective models predict a decrease of the critical temperatures in rotating QCD. Nevertheless, lattice simulations showed that the critical temperature in gluodynamics increases due to rotation. We extend the lattice study to the theory with dynamical fermions. We present the first lattice results for rotating QCD with $N_f=2$ dynamical clover-improved Wilson quarks. We also study separately the effect of rotation on gluonic and fermionic degrees of freedom. It is shown that separate rotations of gluons and fermions have opposite effects on the critical temperatures. In aggregate, the pseudo-critical temperatures in QCD increase with angular velocity. Dependence of the results on the pion mass is also discussed.

    ↳ hep-lathep-phhep-thPoS(2023)·36 citations
37. 37*

    Life at the Landau pole

    Paul Romatschke🇺🇸

    If a quantum field theory has a Landau pole, the theory is usually called 'sick' and dismissed as a candidate for an interacting UV-complete theory. In a recent study on the interacting 4d O(N) model at large N, it was shown that at the Landau pole, observables remain well-defined and finite. In this work, I study both relevant and irrelevant deformations of the said model at the Landau pole, finding that physical observables remain unaffected. Apparently, the Landau pole in this theory is benign. As a phenomenological application, I compare the O(N) model to QCD, by identifying ${\Lambda }_{\overline{\mathrm{MS}}}$ with the Landau pole in the O(N) model.

    ↳ hep-thhep-phnucl-thAppliedMath(2024)·19 citations
38. 38*

    A Guide to AMSB QCD

    Csaba Csáki🇺🇸 · Andrew Gomes🇺🇸 · Hitoshi Murayama🇺🇸 · Bea Noether🇺🇸 · Digvijay Roy Varier🇺🇸 · Ofri Telem🇮🇱

    We present a careful study of the chiral symmetry breaking minima and the baryonic directions in supersymmetric QCD ($SU(N_c)$ with $N_f$ flavors) perturbed by Anomaly Mediated Supersymmetry Breaking (AMSB). For the s-confining case of $N_f=N_c+1$ and most of the free-magnetic phase ($N_f\le 1.43N_c$) we find that naive tree level baryonic runaways are stabilized by loop effects. Runaways are present, however, for the upper end of the free magnetic phase ($N_f\gtrsim 1.43N_c$) and into conformal window, signaling the existence of incalculable minima at large field values of $\mathcal{O}(\Lambda )$. Nevertheless, the chiral symmetry breaking points are locally stable, and are expected to continuously connect to the vacua of QCD for large SUSY breaking. The case of $N_f=N_c$ requires particular care due to the inherently strongly coupled nature of the quantum modified moduli space. Due to the incalculability of critical Kähler potential terms, the stability of the chiral symmetry breaking point along baryonic directions cannot be determined for $N_f=N_c$. With the exception of this case, all theories to which AMSB can be applied ($N_f<3N_c$) possess stable chiral symmetry breaking minima, and all theories with $N_f\lesssim 1.43N_c$ (aside from $N_f=N_f$) are protected from runaways to incalculable minima.

    ↳ hep-thhep-phPRD(2023)·22 citations
39. 39*

    Q-ball Superradiance

    Paul M. Saffin🇬🇧 · Qi-Xin Xie🇨🇳 · Shuang-Yong Zhou🇨🇳

    Q-balls are non-topological solitons that coherently rotate in field space. We show that these coherent rotations can induce superradiance for scattering waves, thanks to the fact that the scattering involves two coupled modes. Despite the conservation of the particle number in the scattering, the mismatch between the frequencies of the two modes allows for the enhancement of the energy and angular momentum of incident waves. When the Q-ball spins in real space, additional rotational superradiance is also possible, which can further boost the enhancements. We identify the criteria for the energy and angular momentum superradiance to occur.

    ↳ hep-thgr-qchep-phPRL(2023)·31 citations
40. 40*

    A critical response to Moshe Chaichian and colleagues on mass dimension one fields, and related matters

    Dharam Vir Ahluwalia🇦🇺 · Cheng-Yang Lee🇨🇳

    In a recent article published in EPJC, Moshe Chaichian and colleagues have presented an overarching critique of mass dimension one fields and related matters. In this Letter we show without ambiguity where these authors go wrong.

    ↳ hep-thgr-qchep-ph0 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.