Tue·Feb 7, 2023Tuesday·February 7, 2023

1. 01*

   The massless non-adjacent double off-shell scalar box integral -- branch cut structure and all-order epsilon expansion

   Juliane Haug🇩🇪 · Fabian Wunder🇩🇪

   We generalize the result of our recent paper on the massless single off-shell scalar box integral to the case of two non-adjacent end points off the light cone. An analytic result in $d=4-2\epsilon$ dimensions is established in terms of four Gauss hypergeometric ${}_2{\mathrm{F}}_1$ functions respectively their single-valued counterparts. This allows for an explicit splitting of real and imaginary parts, as well as an all-order $\epsilon$-expansion in terms of single-valued polylogarithms.

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

   Muon g-2 and Dark Matter in the NUGM + NUHM2 model

   M. Adeel Ajaib🇺🇸 · Fariha Nasir🇺🇸

   We analyze the NUGM + NUHM2 model and study the implications of recent experimental constraints on the parameter space of this model. We also explore the nature of dark matter in this model and present the parameter space characterized by various compositions of the neutralino. The region of the parameter space that satisfies the observed deviation in the anomalous magnetic moment of the muon is explored more rigorously. We also present results corresponding to the production cross section and decay widths of a light CP-even Higgs boson and observe that there is a narrow region of the parameter space corresponding to a light stau which explains the observed deviation in the muon g-2 and also leads to enhancement in the Higgs production and decay widths.

   hep-ph3 citations
3. 03*

   TeV-scale leptoquark searches at the LHC and their E${}_6$SSM Interpretation

   Murad Ali🇷🇼 · Shaaban Khalil🇪🇬 · Stefano Moretti🇬🇧 · Shoaib Munir🇷🇼 · Roman Nevzorov🇷🇺 · Alexandre Nikitenko🇷🇺 · Harri Waltari🇸🇪

   We perform a model-independent search for leptoquarks (LQs) at the Large Hadron Collider through their pair-production and subsequent decay into $t\bar{t}\tau \tau$ intermediate states. We show that, assuming full luminosity of the Run 2, a fully hadronic signal emerging from this intermediate state can surpass in sensitivity the established searches relying on leptons in the final state. Our conclusion is supported by a thorough Monte-Carlo analysis, and we advocate the deployment of our proposed search channel in the proper experimental setting of the Run 3. Furthermore, in order to highlight the full scope of this approach for constraining LQ theories, we interpret our results in the context of the string-inspired Exceptional Supersymmetric Standard Model, which naturally predicts the $S_1-$type scalar LQ states that we analyse here.

   hep-phhep-exJHEP(2023)·5 citations
4. 04*

   Testing Neutrino Dipole Portal by Long-lived Particle Detectors at the LHC

   Wei Liu🇨🇳 · Yu Zhang🇨🇳

   We discuss the potential of using detectors aimed for searching long-lived particles~(LLP) at the high-luminosity LHC run, to probe the neutrino dipole models. This is achieved by taking the heavy neutral leptons~(HNL) of the models as candidates of the LLPs. Taking into account the dipole couplings to the weak bosons, $d_{W,Z}$, which control the production of the HNLs at the LHC, we discuss the reach on the electromagnetic dipole couplings, $d_{\gamma }$, by searching for a single high-energy photon at LLP detectors. Four typical scenarios are considered in this paper, scenario A, B with $d_W=0$ or $d_Z=0$, and scenario C, D with $d_{W,Z}\gg d_{\gamma }$. We show the sensitivity on $d_{\gamma }$, can be fairly different depending on the relations between the $d_{W,Z}$ and $d_{\gamma }$. And the LLP detectors can potentially extend the sensitivity on dipole couplings during the High-luminosity runs of the LHC in certain scenarios.

   hep-phhep-exEPJC(2023)·15 citations
5. 05*

   Probing the $Hgg$ coupling through the jet charge correlation in Higgs boson decay

   Xiao-Rui Wang🇨🇳 · Bin Yan🇨🇳

   The effective coupling of the Higgs boson to gluons determines the production rate of the Higgs boson at the LHC and plays a crucial role to measure the Higgs properties. In this paper, we propose a novel method to extract the Higgs gluon gauge coupling information at the future lepton colliders, by utilizing the jet charge asymmetry of the two leading jets from the Higgs boson decay. Owing to the jet charge correlation nature of the Higgs decay products, we demonstrate that this asymmetry value would be close to one for the signal $H\to gg$, while it is always larger than one for the dominated backgrounds. With the help of the jet charge information, it is possible to constrain the Higgs gluon effective coupling very well in the future Higgs factory and this conclusion is not sensitive to the jet charge parameter $\kappa$.

   hep-phhep-exPRD(2023)·11 citations
6. 06*

   The nonleptonic decays of $b$-flavored mesons to $S$-wave charmonium and charm meson states

   Kalpalata Dash · Lopamudra Nayak🇮🇳 · P. C. Dash · Rabinarayan Panda🇮🇳 · Susmita Kar🇮🇳 · N. Barik🇮🇳

   The detection of radially excited heavy meson \\states in recent years and measurement of heavy meson decays, particularly $B_c^{+}\to J/\psi D_s^{+}$ and $B_c^{+}\to J/\psi D_s^{\ast +}$, by the LHCb and ATLAS Collaborations, have aroused a lot of theoretical interest in the nonleptonic decays of $b$-flavored mesons. In this paper, we study the exclusive two-body nonleptonic ${\bar{B}}^0$, $\overline{B_s^0}$, $B^{-}$ and $B_c^{-}$-meson decays to two vector meson ($V_1(nS)V_2$) states. Assuming the factorization hypothesis, we calculate the weak-decay form factors from the overlapping integrals of meson wave functions, in the framework of the relativistic independent quark (RIQ) model. We find a few dominant decay modes: $B^{-}\to D^{\ast 0}{\rho }^{-}$, $\overline{B^0}\to D^{\ast +}{\rho }^{-}$, $\overline{B_s^0}\to D_s^{\ast +}{\rho }^{-}$, $B^{-}\to J/\psi K^{\ast -}$ and $B_c^{-}\to J/\psi D_s^{\ast -}$ with predicted branching fractions of 1.54, 1.42, 1.17, 0.53 and 0.52 (in $\%$), which are experimentally accessible. The predicted branching fractions for corresponding decay modes to excited ($2S$) states, obtained in the order $\mathcal{O}(10^{-3}-10^{-4})$ lie within the detection accuracy of the current experiments at LHCb and Tevatron. The sizeable $CP$-odd fractions predicted for $B_c^{-}$-meson decay to two charmful states: $D^{\ast 0}{D}_{(s)}^{\ast -}$ and ${\bar{D}}^{\ast 0}{D}_{(s)}^{\ast -}$ indicate significant $CP$-violation hinting at the so-called new physics beyond the standard model.

   hep-phEPJC(2023)·4 citations
7. 07*

   Reflective ability and its energy dependence

   S.M. Troshin🇷🇺 · N.E. Tyurin🇷🇺

   We introduce the notion of reflective ability and discuss its energy dependence using rational form of unitarization. Correspondence with the phase of exponential unitarization is traced. Increase of the reflective ability of interaction region starts at the LHC energies. Numerical estimates are given.

   hep-phMod.Phys.Lett.A(2023)·4 citations
8. 08*

   Comment on "Axion-matter coupling in multiferroics"

   Alexander Balatsky🇸🇪 · Benjo Fraser🇸🇪

   A previous publication [H. S. Roising et al., Phys. Rev. Research 3, 033236 (2021)] involving the current authors pointed out a coupling between dark matter axions and ferroic orders in multiferroics. In this comment we argue that using this coupling for dark matter sensing is likely not feasible for the material class we considered, with present-day technologies and level of materials synthesis. The proposed effect (for QCD axions) is small and is overwhelmed by thermal noise. This finding means that likely materials for the proposed detection scheme would need to be found with significantly lower magnetic ordering temperatures.

   hep-ph8 citations
9. 09*

   A Comparative Study of Z${}^{\prime }$ mediated Charged Lepton Flavor Violation at future lepton colliders

   Jingshu Li🇨🇳 · Wanyue Wang🇨🇳 · Xunye Cai🇨🇳 · Chuxue Yang🇨🇳 · Meng Lu🇨🇳 · Zhengyun You🇨🇳 · Sitian Qian🇨🇳 · Qiang Li🇨🇳

   Charged lepton flavor violation (CLFV) represents a transition between charged leptons of different generations that violates lepton flavor conservation, which is a clear signature of possible new physics beyond the standard model. By exploiting a typical example model of extra Z${}^{\prime }$ gauge boson, we perform a detailed comparative study on CLFV searches at several future lepton colliders, including a 240 GeV electron-positron collider and a TeV scale muon collider. Based on detailed signal and background Monte-Carlo studies with fast detector simulations, we derive the potentials in searching for Z${}^{\prime }$ mediated CLFV couplings with $e\mu$, $e\tau$ and $\mu \tau$ of different future colliders. The results are compared with the current limits set by either low-energy experiments or the high-energy LHC experiments. We find that the sensitivity of the $\tau$ related CLFV coupling strength at future lepton colliders will be significantly improved comparing with the current best constraints.

   hep-phJHEP(2023)·12 citations
10. 10*

    Viscous QCD medium effects on the bottom quark transport coefficients

    Adiba Shaikh🇮🇳 · Sadhana Dash🇮🇳 · Basanta K. Nandi🇮🇳

    The bottom quark transport coefficients, i.e., drag and diffusion coefficients, have been studied for the collisional and soft gluon radiative processes within the viscous QCD medium. The thermal medium effects are incorporated using the effective fugacity quasiparticle model (EQPM). Both the shear and bulk viscous effects at leading order are embedded through the near-equilibrium distribution functions of the quark-gluon plasma (QGP) constituent quasiparticles. The transport coefficients' dependence on the bottom quark's initial momentum and QGP temperature has been investigated. The relative dominance of the radiative over the collisional process for the bottom quark seems to occur at a higher initial momentum compared to that of the charm quark. In contrast, the effect of the viscous corrections seems to be more for the charm quark.

    hep-phnucl-thEPJC(2023)·6 citations
11. 11*

    Evolution of eccentricities induced by geometrical and quantum fluctuations in proton-nucleus collisions

    S. Demirci🇫🇮 · P. Guerrero-Rodríguez🇵🇹

    We compute the azimuthal eccentricities arising from initial stage fluctuations in high energy proton-nucleus collisions at proper times $\tau \ge 0^{+}$. We consider two sources of fluctuations, namely the geometrical structure of the proton and the fluctuation of color fields carried by both proton and nucleus. Describing these effects with Gaussian models allows us to analytically calculate the one- and two-point correlators of energy density, from which the eccentricities are obtained. We compute the proper time evolution of these quantities by approximating the Glasma dynamics in terms of linearized Yang-Mills equations, which we solve by assuming free field propagation and adopting the dilute-dense limit.

    hep-phPRD(2023)·6 citations
12. 12*

    Single top quark production at ultra-high energies

    V. A. Okorokov (National Research Nuclear University MEPhI)🇷🇺

    The processes with single top quark production provide a prototype search for the types of final state that are expected in many new physics scenarios. Some distinctive features are considered for particle production in the top sector in ultra-high energy domain which can be covered partly in the collisions of cosmic ray particles with atmosphere. The single top quark production through electroweak interaction is studied within the Standard Model and the Effective Field Theory approach used for calculations of total partonic cross sections in $s$-channel. These quantitative results can be important for both the future collider experiments at center-of-mass energy frontier and the improvement of the phenomenological models for development of the cosmic ray cascades in ultra-high energy domain. Thus the study allows the better understanding of heavy particle production and emphasizes the exciting interrelation between the high-energy physics on accelerators and ultra-high energy cosmic ray measurements.

    hep-phPhys.Atom.Nucl.(2023)·3 citations
13. 13*

    Unpolarized generalized parton distributions of light and heavy vector mesons

    Chao Shi🇨🇳 · Jicheng Li🇨🇳 · Pei-Lin Yin🇨🇳 · Wenbao Jia🇨🇳

    We study the leading-twist unpolarized generalized parton distributions (GPDs) of light and heavy vector mesons, i.e., the $\rho$, $J/\psi$ and ${\rm Y}$, at zero skewness. An ansatz incorporating the zero mode contribution is introduced to modify the light front overlap representation of GPDs. The leading Fock-state light front wave functions (LF-LFWFs) of vector mesons from DS-BSEs approach are then employed to study the meson GPDs. The light front spatial distribution of valence quarks within vector mesons is then studied with the impact parameter dependent GPD (IPD GPD). We also investigate the electromagnetic and gravitational form factors, which are the first and second Mellin moments of the GPDs. The light-cone mass radius of $\rho$ is determined to be 0.30 fm, close to a recent NJL model prediction 0.32fm. For $J/\psi$ and ${\rm Y}$, they are predicted to be 0.151fm and 0.089 fm respectively.

    hep-phPRD(2023)·17 citations
14. 14*

    Freeze-in Production of Pseudo-Nambu-Goldstone Dark Matter Model with a Real Scalar

    Xue-Min Jiang🇨🇳 · Chengfeng Cai🇨🇳 · Yu-Hang Su🇨🇳 · Hong-Hao Zhang🇨🇳

    In this work, we study a pseudo-Nambu-Goldstone boson (pNGB) dark matter model extended with a real scalar. The dark sector is assumed to be feebly coupled with the standard model (SM) via a Higgs portal, so that the pNGB dark matter is produced by the freeze-in mechanism. Since the production happened in a very high energy era, we introduce an extra scalar field which is weakly coupled to the SM for stablizing the electroweak vacuum. Our model can reproduce the correct relic abundance of dark matter favored by observations. In addition, we determine the evolution of couplings in higher energy scale by solving the renormalization group equations, and show that the self coupling of the real scalar, ${\lambda }_S$, and the mixing coupling between the Higgs field and the real scalar, ${\lambda }_{HS}$ are stringently constrained by the conditions of vacuum stability and couplings perturbativity up to the Planck scale. We also find that the relic abundance of DM is insensitive to the values of ${\lambda }_S$ and ${\lambda }_{HS}$ unless the dominant production processes are $\overline{H}+H(S+S)\to \varphi +\varphi$ via t- and u-channels.

    hep-ph5 citations
15. 15*

    Towards the precise description of Composite Higgs models at colliders

    Diogo Buarque Franzosi🇸🇪

    We present a framework to study the interactions among Nambu-Goldstone bosons (NGB), pseudo-NGB (pNGBs) and gauge bosons in Composite Higgs (CH) models at high energies, including operators of order $\mathcal{O}(p^4)$ and $\mathcal{O}(p^2{g}^2)$ in the chiral expansion and topological terms. The set of (p)NGBs comprises the longitudinal modes of electroweak bosons, the Higgs boson, and possibly other scalar states from the dynamical spontaneous electroweak symmetry breaking. The framework is implemented in a collider simulation tool especially suited for the study of Goldstone Boson Scattering (GBS), which includes vector boson scattering (VBS), di-Higgs production via vector boson fusion (VBF) and the pair production of other pNGBs via VBF.

    hep-ph2 citations
16. 16*

    Searching for doubly charmed tetraquark candidates $T_{cc}$ and $T_{cc\bar{s}}$ in $B_c$ decays

    Yuan Li🇨🇳 · Ying-Bo He🇨🇳 · Xiao-Hai Liu🇨🇳 · Baoyi Chen🇨🇳 · Hong-Wei Ke🇨🇳

    In this work, we propose to search for the exotic doubly charmed meson $T_{cc}^{+}$ and its analog $T_{cc\bar{s}}^{+}$ in $B_c^{+}$ decays, which provide a good environment for the formation of the exotic state containing double charm quarks. Within the molecular scheme, the production of $T_{cc}^{+}$ and $T_{cc\bar{s}}^{+}$ through various rescattering processes with different intermediate states are investigated. For the moderate values of model parameters, the branching ratios of $B_c^{+}$ decaying into $T_{cc}^{+}{\bar{D}}^0$, $T_{cc}^{+}{\bar{D}}^{\ast 0}$, $T_{cc\bar{s}}^{+}{\bar{D}}^0$ and $T_{cc\bar{s}}^{+}{\bar{D}}^{\ast 0}$ are estimated to be of the order of $10^{-7}$, $10^{-5}$, $10^{-6}$ and $10^{-4}$, respectively, which may be tested by future experiments.

    hep-phhep-exEPJC(2023)·13 citations
17. 17*

    Spectroscopic Analysis of Hidden-Charm Pentaquarks

    Ankush Sharma🇮🇳 · Alka Upadhyay🇮🇳

    In this work, the multiquark approach is used to analyze the spectroscopy of hidden-charm pentaquark states, motivated by recent discoveries at the LHCb collaboration. Using the SU(3) flavor representation, pentaquarks having $J^P=5/2^{-}$ are arranged into 10 (decuplet) of the SU(3) flavor multiplets. The masses of pentaquarks are calculated using the extension of the Gursey-Radicati mass formula and the effective mass scheme. Also, we calculated the magnetic moments of the hidden-charm pentaquarks using the effective mass and shielded charge technique. Further, we suggested the possible production modes for $J^P=5/2^{-}$ pentaquarks from the decay of bottom baryons, which consist of pentaquark states as intermediate states. Our results for masses demonstrate reasonable agreement with the available data and our analysis for both masses and magnetic moments may be useful for future experimental studies.

    hep-phJ.Phys.G(2024)·10 citations
18. 18*

    On the applicability of the Landau-Zener formula to axion-photon conversion

    Pierluca Carenza🇸🇪 · M. C. David Marsh🇸🇪

    Axions and photons resonantly interconvert in regions where the plasma frequency approximately equals the axion mass. This process is directly analogous to an avoided level crossing in quantum mechanics, for which the celebrated Landau-Zener (LZ) formula provides a simple, non-perturbative solution for the conversion probability. The LZ formula is commonly used in studies of axion-photon conversion; however, in this context, it relies on the assumption that the magnetic field variation is small compared to variations of the plasma frequency, which is frequently not the case in real plasmas. We derive a generalised version of the LZ formula by allowing the boundaries to be located at a scale that is similar to the inhomogeneities. We find that the LZ formula fails when the oscillation range is small compared to the resonance region. This failure is more severe in the adiabatic limit, when the plasma frequency varies slowly, resulting in a conversion probability that is not maximal as opposed to a naive application of the LZ formula. Moreover, we consider circumstances where the generalised LZ formula does not apply and present an alternative semi-classical approximation with complementary regime of validity.

    hep-phJCAP(2023)·22 citations
19. 19*

    Linear power corrections to single top production processes at the LHC

    Sergei Makarov🇩🇪 · Kirill Melnikov🇩🇪 · Paolo Nason🇮🇹 · Melih A. Ozcelik🇫🇷

    We discuss the linear power corrections to the electroweak production of top quarks at the LHC using renormalon calculus. We show how such non-perturbative corrections can be obtained using the Low-Burnett-Kroll theorem, which provides the first subleading term to the expansion of the real-emission amplitudes around the soft limit. We demonstrate that there are no linear power corrections to the total cross sections of arbitrary processes of a single top production type provided that these cross sections are expressed in terms of a short-distance top quark mass. We also derive a universal formula for the linear power corrections to generic observables that involve the top-quark momentum.

    hep-phJHEP(2023)·10 citations
20. 20*

    Long-lived particle phenomenology in the 2HDM+$a$ model

    Ulrich Haisch🇩🇪 · Luc Schnell🇩🇪

    Higgs decays displaced from the primary interaction vertex represent a striking experimental signature that is actively searched for by the ATLAS, CMS and LHCb collaborations. We point out that signals of this type appear in the context of the 2HDM+$a$ model if the mixing angle $\theta$ of the two CP-odd weak spin-0 eigenstates is tiny and the dark matter (DM) sector is either decoupled or kinematically inaccessible. Utilising two suitable benchmark scenarios, we determine the constraints on the parameter space of the 2HDM+$a$ model that are set by the existing LHC searches for long-lived particles (LLPs) in Higgs decays. We find that depending on the precise mass spectrum of the spin-0 states, mixing angles $\theta$ in the ballpark of a few $10^{-8}$ to $10^{-5}$ can be excluded based on LHC Run II data. This finding emphasises the unique role that searches for displaced signatures can play in constraining the parameter space of the 2HDM+$a$ model. The ensuing DM phenomenology is also discussed. In particular, we show that parameter choices leading to an interesting LLP phenomenology can simultaneously explain the DM abundance observed in today's Universe.

    hep-phhep-exJHEP(2023)·13 citations
21. 21*

    Recent developments in warm inflation

    Vahid Kamali🇨🇦 · Meysam Motaharfar🇺🇸 · Rudnei O. Ramos🇧🇷

    Warm inflation, its different particle physics model implementations and the implications of dissipative particle production for its cosmology are reviewed. First, we briefly present the background dynamics of warm inflation and contrast it with the cold inflation picture. An exposition of the space of parameters for different well-motivated potentials, which are ruled out, or severely constrained in the cold inflation scenario, but not necessarily in warm inflation, is provided. Next, the quantum field theory aspects in realizing explicit microscopic models for warm inflation are given. This includes the derivation of dissipation coefficients relevant in warm inflation for different particle field theory models. The dynamics of cosmological perturbations in warm inflation are then described. The general expression for the curvature scalar power spectrum is shown. We then discuss in details the relevant regimes of warm inflation, the weak and strong dissipative regimes. We also discuss the results predicted in these regimes of warm inflation and how they are confronted with the observational data. We explain how the dissipative dynamics in warm inflation can address several long-standing issues related to (post-) inflationary cosmology. This includes recent discussions concerning the so-called swampland criteria and how warm inflation can belong to the landscape of string theory.

    hep-phastro-ph.COgr-qchep-thUniverse(2023)·94 citations
22. 22*

    Positivity Bounds on Higgs-Portal Dark Matter

    Seong-Sik Kim🇰🇷 · Hyun Min Lee🇰🇷 · Kimiko Yamashita🇰🇷

    We consider the positivity bounds for WIMP scalar dark matter with effective Higgs-portal couplings up to dimension-8 operators. Taking the superposed states for Standard Model Higgs and scalar dark matter, we show that the part of the parameter space for the effective couplings, otherwise unconstrained by phenomenological bounds, is ruled out by the positivity bounds on the dimension-8 derivative operators. We find that dark matter relic density, direct and indirect detection and LHC constraints are complementary to the positivity bounds in constraining the effective Higgs-portal couplings. In the effective theory obtained from massive graviton or radion, there appears a correlation between dimension-8 operators and other effective Higgs-portal couplings for which the strong constraint from direct detection can be evaded. Nailing down the parameter space mainly by relic density, direct detection and positivity bounds, we find that there are observable cosmic ray signals coming from the dark matter annihilations into a pair of Higgs bosons, $WW$ or $ZZ$.

    hep-phastro-ph.COhep-thJHEP(2023)·11 citations
23. 23*

    Third family quasi-Yukawa unification: Higgsino dark matter, NLSP gluino and all that

    Qaisar Shafi🇺🇸 · Amit Tiwari🇺🇸 · Cem Salih Un🇹🇷

    We explore the implications of third family ($t-b-\tau$) quasi-Yukawa unification (QYU) for collider and dark matter (DM) searches within the framework of a supersymmetric $SU(4{)}_c\times SU(2{)}_L\times SU(2{)}_R$ model. The deviation from exact Yukawa unification is quantified through the relation $y_t:y_b:y_{\tau }=|1+C|:|1-C|:|1+3C|$, with $C$ being a real parameter ($|C|\le 0.2$). We allow for the breaking of left-right symmetry both by the soft scalar and gaugino mass parameters and obtain a variety of viable solutions that predict the sparticle mass spectrum including LSP DM (whose stability is guaranteed by a $Z_2$ gauge symmetry). We highlight solutions that include an NLSP gluino with mass $\sim$ 1.3-2.5 TeV, which should be accessible at LHC Run 3. There also exist NSLP stop solutions with masses heavier than about 1.8 TeV, which are consistent with the LSP neutralino dark matter relic density through stop-neutralino coannihilation. We identify A-resonance solutions with DM mass $\sim$ 0.8 - 2 TeV, as well as bino-chargino, bino-slepton and bino-stau co-annihilation scenarios. Finally, we also identify Wino-like ($\sim 99\%$) and Higgsino-like ($\sim 99\%$) solutions whose masses are heavier than about 1.5 TeV and 1 TeV, respectively. These solutions are compatible with the desired dark matter relic density and testable in ongoing and future direct detection experiments.

    hep-phPRD(2023)·12 citations
24. 24*

    Flavor structure of the energy-momentum tensor form factors of the proton

    Ho-Yeon Won🇰🇷 · Hyun-Chul Kim🇰🇷 · June-Young Kim🇺🇸

    The energy-momentum tensor form factors furnish information on the mechanics of the proton. It is essential to compute the generalized isovector-vector form factors to examine the flavor structure of the energy-momentum tensor form factors. The flavor-decomposed form factors reveal the internal structure of the proton. The up quark dominates over the down quark for the mass and spin of the proton, whereas the down quark takes over the up quark for the $D$-term form factor. We investigate for the first time the isovector $\bar{c}(t)$ form factor of the proton and its physical implications. The flavor-decomposed $\bar{c}(t)$ form factors of the proton unveil how the up-quark contribution is exactly canceled by the down-quark contribution inside a proton within the framework of the pion mean-field approach. While the proton $\bar{c}(t)$ form factor does not contribute to the proton mass, its flavor structure sheds light on how the strong force fields due to the $\bar{c}(t)$ form factor characterize the stability of the proton.

    hep-phhep-exhep-latPLB(2024)·16 citations
25. 25*

    Natural Suppression of FCNCs at the One-Loop Level in $Z^{\prime }$ Models with Implications for K, D and B Decays

    Andrzej J. Buras🇩🇪

    We analyse $Z^{\prime }$ contributions to FCNC processes at the one-loop level. In analogy to the CKM matrix we introduce two $3\times 3$ unitary matrices ${\hat{\Delta }}_d(Z^{\prime })$ and ${\hat{\Delta }}_u(Z^{\prime })$ which are also hermitian. They govern the flavour interactions mediated by $Z^{\prime }$ between down-quarks and up-quarks, respectively, with ${\hat{\Delta }}_d(Z^{\prime })={\hat{\Delta }}_u(Z^{\prime })\equiv {\hat{\Delta }}_L(Z^{\prime })$ for left-handed currents due to the unbroken ${\text{SU(2)}}_L$ gauge symmetry. This assures the suppression of these contributions to all $Z^{\prime }$ mediated FCNC processes at the one-loop level. As, in contrast to the GIM mechanism, one-loop $Z^{\prime }$ contributions to flavour observables in $K$ and $B_{s,d}$ systems are governed by down-quark masses, they are $\mathcal{O}(m_b^2/M_{Z^{\prime }}^2)$ and negligible. With the $\mathcal{O}(m_t^2/M_{Z^{\prime }}^2)$ suppression they are likely negligible also in the $D$ system. We present an explicit parametrization of ${\hat{\Delta }}_L(Z^{\prime })$ in terms of two mixing angles and two complex phases that distinguishes it profoundly from the CKM matrix. This framework can be generalized to purely leptonic decays with matrices analogous to the PMNS matrix but profoundly different from it. Interestingly, the breakdown of flavour universality between the first two generations and the third one, both for quark and lepton couplings to $Z^{\prime }$, is identified as a consequence of ${\hat{\Delta }}_L(Z^{\prime })$ being hermitian. The importance of the unitarity for both ${\hat{\Delta }}_L(Z^{\prime })$ and the CKM matrix in the light of the Cabibbo anomaly is emphasized.

    hep-phhep-exhep-lat4 citations
26. 26*

    Cosmologically Varying Kinetic Mixing

    Xucheng Gan🇺🇸 · Di Liu🇫🇷

    The portal connecting the invisible and visible sectors is one of the most natural explanations of the dark world. However, the early-time dark matter production via the portal faces extremely stringent late-time constraints. To solve such tension, we construct the scalar-controlled kinetic mixing varying with the ultralight CP-even scalar's cosmological evolution. To realize this and eliminate the constant mixing, we couple the ultralight scalar within $10^{-33}\text{eV}\lesssim m_0\ll \text{eV}$ with the heavy doubly charged messengers and impose the ${\mathbb{Z}}_2$ symmetry under the dark charge conjugation. Via the varying mixing, the $\text{keV}-\text{MeV}$ dark photon dark matter is produced through the early-time freeze-in when the scalar is misaligned from the origin and free from the late-time exclusions when the scalar does the damped oscillation and dynamically sets the kinetic mixing. We also find that the scalar-photon coupling emerges from the underlying physics, which changes the cosmological history and provides the experimental targets based on the fine-structure constant variation and the equivalence principle violation. To ensure the scalar naturalness, we discretely re-establish the broken shift symmetry by embedding the minimal model into the ${\mathbb{Z}}_N$-protected model. When $N\sim 10$, the scalar's mass quantum correction can be suppressed much below $10^{-33}\text{eV}$.

    hep-phastro-ph.COhep-thJHEP(2023)·31 citations
27. 27*

    Probing the jet transport coefficient of cold nuclear matter in electron-ion collisions

    Peng Ru🇨🇳 · Zhong-Bo Kang🇺🇸 · Enke Wang🇨🇳 · Hongxi Xing🇨🇳 · Ben-Wei Zhang🇨🇳

    We present a study of the nuclear-medium induced transverse momentum broadening of particle production in future electron-ion-collision~(EIC) experiments. By considering the multiple scattering between hard partons and cold nuclear medium within the higher-twist factorization framework in perturbative QCD, we calculate the transverse momentum broadening of single hadron production in semi-inclusive measurements, as well as the nuclear enhancement of the transverse momentum imbalance for di-hadron and heavy-meson pair productions. In particular, a kinematics dependent non-perturbative jet transport coefficient $\hat{q}=\hat{q}(x,Q^2)$ extracted in a global analysis of the current data, together with its uncertainty determined with a Hessian method, are input into our calculations and are available for the community. Significant kinematic and color-state dependences of the nuclear induced broadening/imbalance are predicted. Our results indicate that the future EIC measurements are able to provide powerful constraints on the kinematic dependence of the transport coefficient $\hat{q}$ and thus greatly facilitate the jet tomography of cold nuclear medium.

    ↳ nucl-thhep-exhep-phnucl-ex6 citations
28. 28*

    Steven Weinberg (1933 - 2021)

    Rohini M. Godbole🇮🇳 · Urjit Yajnik🇮🇳

    This is a homage to the memory of Prof. Steven Weinberg who passed away on 23 July 2021.

    ↳ physics.hist-phastro-ph.COhep-phhep-thCURRENT SCIENCE, VOL. 121, NO. 5, 10 SEPT…·0 citations
29. 29*

    Nuclear and Hybrid Equations of State in Light of the Low-Mass Compact Star in HESS J1731-347

    Liam Brodie🇺🇸 · Alexander Haber🇺🇸

    We sample over $500$ relativistic mean-field theories constrained by chiral effective field theory and properties of isospin-symmetric nuclear matter and test them against known stellar structure constraints. This includes a recent mass and radius measurement of a compact object in supernova remnant HESS J1731-347, with an unusually low mass of $M=0.77_{-0.17}^{+0.20}{M}_{\odot }$ and a compact radius of $R=10.4_{-0.78}^{+0.86}$ km. We show that none of the sampled nuclear models meet all constraints at the $68\%$ credibility level, but that hybrid equations of state with a quark matter inner core and nuclear outer core easily can. This indicates a tension between astrophysical constraints and low-energy nuclear theory.

    ↳ nucl-thastro-ph.HEhep-phPRC(2023)·40 citations
30. 30*

    Revisiting ultrahigh-energy constraints on decaying super-heavy dark matter

    Saikat Das🇯🇵 · Kohta Murase🇺🇸 · Toshihiro Fujii🇯🇵

    We revisit constraints on decaying very heavy dark matter (VHDM) using the latest ultrahigh-energy cosmic-ray (UHECR; $E\gtrsim 10^{18}$ eV) data and ultrahigh-energy (UHE) $\gamma$-ray flux upper limits, measured by the Pierre Auger Observatory. We present updated limits on the VHDM lifetime (${\tau }_{\chi }$) for masses up to $\sim 10^{15}$~GeV, considering decay into quarks, leptons, and massive bosons. In particular, we consider not only the UHECR spectrum but their composition data that favors heavier nuclei. Such a combined analysis improves the limits at $\lesssim 10^{12}$ GeV because VHDM decay does not produce UHECR nuclei. We also show that the constraints from the UHE $\gamma$-ray upper limits are $\sim 10$ more stringent than that obtained from cosmic rays, for all of the Standard Model final states we consider. The latter improves our limits to VHDM lifetime by a factor of two for dark matter mass $\gtrsim 10^{12}$ GeV.

    ↳ astro-ph.HEhep-phPRD(2023)·46 citations
31. 31*

    Gravity Beyond Einstein? Yes, but in Which Direction?

    Demosthenes Kazanas🇬🇷 · Demetrios Papadopoulos · Dimitris Christodoulou🇺🇸

    We present qualitative arguments in favor of an extension of the theory of the gravitational interaction beyond that resulting from the Hilbert-Einstein action. To this end we consider a locally conformal invariant theory of gravity, discussed some thirty years ago by Mannheim and Kazanas. We discuss its exact solution of the static, spherically symmetric configurations and, based on these, we revisit some of the outstanding problems associated with gravity, high energy interactions and sketch potential resolutions within the conformal gravity framework.

    ↳ gr-qchep-phhep-thPhil.Trans.Roy.Soc.Lond.A(2022)·2 citations
32. 32*

    Agnostic black hole spectroscopy: Quasinormal mode content of numerical relativity waveforms and limits of validity of linear perturbation theory

    Vishal Baibhav🇺🇸 · Mark Ho-Yeuk Cheung🇺🇸 · Emanuele Berti🇺🇸 · Vitor Cardoso🇩🇰 · Gregorio Carullo🇩🇰 · Roberto Cotesta🇺🇸 · Walter Del Pozzo🇮🇹 · Francisco Duque🇵🇹

    Black hole spectroscopy is the program to measure the complex gravitational-wave frequencies of merger remnants, and to quantify their agreement with the characteristic frequencies of black holes computed at linear order in black hole perturbation theory. In a "weaker" (non-agnostic) version of this test, one assumes that the frequencies depend on the mass and spin of the final Kerr black hole as predicted in perturbation theory. Linear perturbation theory is expected to be a good approximation only at late times, when the remnant is close enough to a stationary Kerr black hole. However, it has been claimed that a superposition of overtones with frequencies fixed at their asymptotic values in linear perturbation theory can reproduce the waveform strain even at the peak. Is this overfitting, or are the overtones physically present in the signal? To answer this question, we fit toy models of increasing complexity, waveforms produced within linear perturbation theory, and full numerical relativity waveforms using both agnostic and non-agnostic ringdown models. We find that higher overtones are unphysical: their role is mainly to "fit away" features such as initial data effects, power-law tails, and (when present) nonlinearities. We then identify physical quasinormal modes by fitting numerical waveforms in the original, agnostic spirit of the no-hair test. We find that a physically meaningful ringdown model requires the inclusion of higher multipoles, quasinormal mode frequencies induced by spherical-spheroidal mode mixing, and nonlinear quasinormal modes. Even in this "infinite signal-to-noise ratio" version of the original spectroscopy test, there is convincing evidence for the first overtone of the dominant multipole only well after the peak of the radiation.

    ↳ gr-qcastro-ph.HEhep-phPRD(2023)·214 citations
33. 33*

    Carrollian Origins of Bjorken Flow

    Arjun Bagchi🇮🇳 · Kedar S. Kolekar🇮🇳 · Ashish Shukla🇫🇷

    Bjorken flow is among the simplest models of fluids moving near the speed of light ($c$) while Carroll symmetry arises as a contraction of Poincaré group when $c\to 0$. We show that Bjorken flow and its phenomenological approximations are completely captured by Carrollian fluids. Carrollian symmetries arise on generic null surfaces and a fluid moving at $c$ is restricted to such a surface, thereby naturally inheriting the symmetries. Carrollian hydrodynamics is thus not exotic, but rather ubiquitous, and provides a concrete framework for fluids moving at or near the speed of light.

    ↳ hep-thhep-phnucl-thPRL(2023)·68 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.