Tue·Apr 2, 2024Tuesday·April 2, 2024

1. 01*

   Cosmological mass of the photon related to Stueckelberg and Higgs mechanisms

   Lorenzo Gallerani Resca🇺🇸

   I consider electro-weak (EW) masses and interactions generated for photons by vacuum expectation values of Stueckelberg and Higgs fields. I provide a prescription to relate their parametric values to a cosmological range derived from a fundamental Heisenberg uncertainty principle and Einstein-de Sitter cosmological constant and horizon. This yields qualitative connections between microscopic ranges acquired by $W^{\pm }$ or $Z^0$ gauge Bosons and the cosmological scale and minimal mass acquired by $g$-photons. I apply that procedure to an established Stueckelberg-Higgs mechanism, while I consider a similar procedure for a pair of Higgs fields that may spontaneously break all U(1)xSU(2) gauge invariances. My estimates of photon masses and their additional parity-breaking interactions with leptons and neutrinos may be detectable in suitable accelerator experiments. Their effects may also be observable astronomically through massive $g$-photon condensates that may contribute to dark matter and dark energy.

   hep-phgr-qcParticles(2024)·0 citations
2. 02*

   Production and decay of hyperons in a transversely polarized electron-positron collider

   Xu Cao🇨🇳 · Yu-Tie Liang🇨🇳 · Rong-Gang Ping🇨🇳

   The self-polarization of relativistic electrons or positrons moving in a magnetic field at a storage ring occurs through the emission of spin-flip synchrotron radiation, known as the Sokolov-Ternov effect. The resulting transverse polarizations of the colliding electrons and positrons, away from the depolarization resonances, allow for precise investigation of the spin entangled hyperon-antihyperon pairs via virtual photon or charmonium decay. The feasibility study reveals a promising increase in the statistical sensitivity of the \CP violation signal after considering the transverse polarizations of the lepton beams.

   hep-phPRD(2024)·25 citations
3. 03*

   Unitarity constraints and the dispersive matrix

   Guido Martinelli🇮🇹 · Silvano Simula🇮🇹 · Ludovico Vittorio🇫🇷

   We present updated estimates of $|V_{cb}|$ and $R(D^{(\ast )})$ based on all the available theoretical and experimental data on semileptonic $B\to D^{(\ast )}\ell {\nu }_{\ell }$ decays. These values have been obtained by using the Dispersive Matrix method to describe the hadronic form factors. By analysing all the lattice data we get the theoretical values $R^{\mathrm{th}}(D)=0.296\pm 0.008$ and $R^{\mathrm{th}}(D^{\ast })=0.262\pm 0.009$, which are consistent with the corresponding HFLAV averages at the $\simeq 2.0\sigma$ and the $\simeq 1.5\sigma$ level, respectively. Moreover, from a bin-per-bin study of the experimental data we obtain the values $|V_{cb}|=(41.0\pm 1.2)\cdot 10^{-3}$ from $B\to D$ decay and $|V_{cb}|=(39.92\pm 0.64)\cdot 10^{-3}$ from $B\to D^{\ast }$ one, whose differences with the latest inclusive determinations never exceed the $\simeq 2.5\sigma$ level.

   hep-phhep-exhep-lat0 citations
4. 04*

   New method for the solution of the two-body Dirac equation for the positronium bound states

   E.M. Tursunov · Sh.G. Norbutaev · B.A. Fayzullaev

   A new theoretical method is developed to solve the two-body bound-state Dirac equation for positronium. Only Coulomb potential was included in the Dirac Hamiltonian. It is shown that the two-body Dirac Hamiltonian can be written in the Hermitian matrix form of the 4$\times$4 size and diagonalized in the momentum-state representation. Numerical results for the energy spectrum of the para- and ortho-positronium ground states performed within the variational method using the harmonic oscillator basis functions are in good agreement with a high-precision finite-element method of T.C. Scott et al. After the Fourier transformation into the coordinate-state representation the bound state wave functions of the para-Ps and ortho-Ps do not contain any singularity at the origin in contrast to the method mentioned above. The weights of the large-small and small-large components of the ground state wave functions are estimated to be of order 10${}^{-6}$, while the weight of the small-small component is of order 10${}^{-12}$.

   hep-phhep-exnucl-thquant-ph1 citation
5. 05*

   Meson mass and width: Deep learning approach

   M. Malekhosseini🇮🇷 · S. Rostami🇮🇷 · A. R. Olamaei🇮🇷 · R. Ostovar🇮🇷 · K. Azizi🇮🇷

   It is fascinating to predict the mass and width of the ordinary and exotic mesons solely based on their quark content and quantum numbers. Such prediction goes beyond conventional methodologies traditionally employed in hadron physics for calculating or estimating these quantities. The relation between the quantum numbers and the properties of the mesons, such as the mass and width, is complicated in the world of particle physics. However, the deep neural network (DNN) as a subfield of machine learning techniques provides a solution to this problem. By analyzing large datasets, deep learning algorithms can automatically identify complex patterns among the particles' quantum numbers, and their mass and width, that would otherwise require complex calculations. In this study, we present two approaches using the DNNs to estimate the mass of some ordinary and exotic mesons. Also for the first time, the DNNs are trained to predict the width of ordinary and exotic mesons, whose widths have not been experimentally known. Our predictions obtained through the DNNs, will be useful for future experimental searches.

   hep-phhep-exhep-latPRD(2024)·10 citations
6. 06*

   Chromomagnetic dipole moments of light quarks in the Bestest Little Higgs Model

   T. Cisneros-Pérez🇲🇽 · E. Cruz-Albaro🇲🇽 · A. Y. Ojeda-Castañeda🇲🇽 · S. E. Solís-Núñez🇲🇽

   In this paper, we research into the anomalous Chromomagnetic Dipole Moment (CMDM), denoted as ${\hat{\mu }}_q^{BLHM}$, of the light quarks $q=(u,c,d,s,b)$ within the framework of the Bestest Little Higgs Model (BLHM) as an extension of the Standard Model (SM). Our investigation encompasses novel interactions among the light quarks, the heavy quark $B$, and the heavy bosons $(W^{\prime \pm },H^{\pm },{\varphi }^{\pm },{\eta }^{\pm })$, incorporating the extended Cabibbo-Kobayashi-Maskawa (CKM) matrix characteristic of the BLHM. We thoroughly explore the permissible parameter space, yielding a spectrum of CMDM values ranging from $10^{-10}$ to $10^{-3}$.

   hep-phCPC(2024)·4 citations
7. 07*

   Electric Dipole Moments in 5+3 Flavor Weak Effective Theory

   Jacky Kumar🇺🇸 · Emanuele Mereghetti🇺🇸

   A fully generic treatment of electric dipole moments (EDMs) is presented in the CP-violating and flavor-conserving weak effective field theory (WET) with five flavors of quarks and three flavors of leptons. We systematically analyze leading contributions to EDMs originating from QCD and QED renormalization group running between the electroweak scale and low energy scales of about 2 GeV. We include the full one-loop anomalous dimension and a subset of two-loop corrections, as well as threshold corrections at the bottom, charm and $\tau$ masses. This allows us to derive master formulae in the space of generic WET for the neutron and proton EDMs, for EDMs of diamagnetic atoms, and the precession frequencies constrained in molecular EDM experiments, from which bounds on the electron EDM are extracted. In particular, our master formulae capture the contributions of WET CP-violating operators with heavy quark and lepton flavors. As an application, we study EDM constraints on the Yukawa couplings of the Higgs boson, in both the linear and non-linear realizations of electroweak symmetry breaking.

   hep-phhep-exJHEP(2024)·11 citations
8. 08*

   Order of the SU(N_f) x SU(N_f) chiral transition via the functional renormalization group

   G. Fejos🇯🇵 · T. Hatsuda🇯🇵

   Renormalization group flows of the $SU(N_f)\times SU(N_f)$ symmetric Ginzburg-Landau potential are calculated for a general number of flavors, $N_f$. Our approach does not rely on the $ϵ$ expansion, but uses the functional renormalization group, formulated directly in $d=3$ spatial dimensions, with the inclusion of all possible (perturbatively) relevant and marginal operators, whose number is considerably larger than those in $d=4$. We find new, potentially infrared stable fixed points spanned throughout the entire $N_f$ range. By conjecturing that the thermal chiral transition is governed by these ``flavor continuous" fixed points, stability analyses show that for $N_f\ge 5$ the chiral transition is of second-order, while for $N_f=2,3,4$, it is of first-order. We argue that the $U_{\mathrm{A}}(1)$ anomaly controls the strength of the first-order chiral transition for $N_f=2,3,4$, and makes it almost indistinguishable from a second-order one, if it is sufficiently weak at the critical point. This could open up a new strategy to investigate the strength of the $U_{\mathrm{A}}(1)$ symmetry breaking around the critical temperature.

   hep-phhep-lathep-thnucl-thPRD(2024)·38 citations
9. 09*

   Primordial black holes from slow phase transitions: a model-building perspective

   Shinya Kanemura🇯🇵 · Masanori Tanaka🇨🇳 · Ke-Pan Xie🇨🇳

   We investigate the formation of primordial black holes (PBHs) through delayed vacuum decay during slow cosmic first-order phase transitions. Two specific models, the polynomial potential and the real singlet extension of the Standard Model, are used as illustrative examples. Our findings reveal that models with zero-temperature scalar potential barriers are conducive to the realization of this mechanism, as the phase transition duration is extended by the U-shaped Euclidean action. We find that the resulting PBH density is highly sensitive to the barrier height, with abundant PBH formation observed for sufficiently high barriers. Notably, the phase transition needs not to be ultra-supercooled (i.e. the parameter $\alpha \gg 1$), and the commonly used exponential nucleation approximation $\Gamma (t)\sim e^{\beta t}$ fails to capture the PBH formation dynamics in such models.

   hep-phastro-ph.COJHEP(2024)·50 citations
10. 10*

    Calculation of the total 10-th order QED contribution to the electron magnetic moment

    Sergey Volkov🇩🇪

    The total 5-loop quantum electrodynamics universal contribution to the anomalous magnetic moments of the leptons was calculated by the author. The obtained value $A_1^{(10)}=5.891(61)$ provides the first complete verification of the previously known value obtained by T. Aoyama, M. Hayakawa, T. Kinoshita, M. Nio (AHKN). The discrepancy is $5\sigma$. The computation includes the recalculation of the part that the author calculated in 2019 using a slightly different method and the calculation of the remaining part of the coefficient. A comparison with the AHKN values in 32 gauge-invariant classes is provided. In addition, the results are divided into 95 small gauge-invariant classes that subdivide the former ones. Such a detailzation is provided for the first time. The method described in previous works of the author was used in general. However, the Monte Carlo integration method is new and is described in detail. Some useful technical information and information on numerical cancellations is also given.

    hep-phPRD(2024)·52 citations
11. 11*

    Freeze-in sterile neutrino dark matter in a feebly gauged $B-L$ model

    Osamu Seto🇯🇵 · Takashi Shimomura🇯🇵 · Yoshiki Uchida🇨🇳

    We consider the gauged $U(1{)}_{B-L}$ model and examine the situation where the sterile neutrino is a dark matter candidate produced by the freeze-in mechanism. In our model, the dark matter $N$ is mainly produced by the decay of a $U(1{)}_{B-L}$ breaking scalar boson $\varphi$. We point out that the on-shell production of $\varphi$ through annihilation of the $U(1{)}_{B-L}$ gauge boson $Z^{\prime }$ plays an important role. We find that the single production of $Z^{\prime }$ from the gluon bath in the early Universe can become the main production modes for $Z^{\prime }$ in some parameter regions. To prevent $N$ from being overproduced, we show that the $U(1{)}_{B-L}$ gauge coupling constant $g_{B-L}$ must be as small as $10^{-16}$--$10^{-10}$. We also consider the case where the decay of $\varphi$ into $N$ is kinematically forbidden. In this case, $N$ is generated by the scattering of $Z^{\prime }$ and the $g_{B-L}$ takes values of $10^{-10}$--$10^{-6}$, which can be explored in collider experiments like FASER and SHiP.

    hep-phJHEP(2025)·8 citations
12. 12*

    Scatophobic Dark Matter

    Gerald X. Gilbert-Thorple🇺🇸 · Jôsé J. Jesus

    An outstanding mystery of dark matter physics is the lack of direct detection signals to date. We suggest that dark matter is scatophobic: due to a repulsive long-range interaction, it is repelled by objects with a large net scat charge, such as the Earth, and is therefore not able to reach direct detection experiments. This represents the first step in a broader theoretical paradigm that we dub the "anti-anthropic principle."

    hep-phastro-ph.CO0 citations
13. 13*

    Total Gluon Helicity from Lattice without Effective Theory Matching

    Zhuoyi Pang🇨🇳 · Fei Yao🇨🇳 · Jian-Hui Zhang🇨🇳

    We propose two approaches for extracting the total gluon helicity contribution to proton spin from lattice QCD, one from local operator matrix elements in a fixed gauge accessible on lattice with feasible renormalization, and the other from gauge-invariant nonlocal gluon correlators. Neither of these approaches requires a matching procedure when converted to the MS scheme. Our proposal resolves a long-standing inconsistency in the literature regarding lattice calculations of the total gluon helicity, and has the potential to greatly facilitate these calculations.

    hep-phhep-latnucl-exnucl-thJHEP(2024)·6 citations
14. 14*

    Weak decays of $B_c$ involving vector mesons in self-consistent covariant light-front approach

    Thejus Mary S.🇮🇳 · Avijit Hazra🇮🇳 · Neelesh Sharma🇮🇳 · Rohit Dhir🇮🇳

    We present a comprehensive analysis of weak transition form factors, semileptonic decays, and nonleptonic decays of $B_c$ meson involving pseudoscalar ($P$) and vector ($V$) meson for bottom-conserving and bottom-changing decay modes. We employ self-consistent covariant light-front quark model (CLFQM), termed as Type-II correspondence, to calculate the $B_c$ to $P(V)$ transition form factors. The Type-II correspondence in the CLF approach gives self-consistent results associated with the $B_j^{(i)}$ functions, which vanish numerically after the replacement $M^{\prime (\prime \prime )}\to M_0^{\prime (\prime \prime )}$ in traditional Type-I correspondence, and the covariance of the matrix elements is also restored. We investigate these effects on bottom-conserving $B_c$ to $P(V)$ form factors that have not yet been studied in CLFQM Type-II correspondence. In addition, we quantify the implications of self-consistency propagating to weak decays involving both bottom-conserving and bottom-changing $B_c$ transition form factors. We use two different parameterizations, the usual three-parameter function of $q^2$ and the model-independent $z$-series expansion, to establish a clear understanding of $q^2$ dependence. Using the numerical values of the form factors, we predict the branching ratios and other physical observables, such as forward-backward asymmetries, polarization fractions, etc., of the semileptonic $B_c$ decays. Subsequently, we predict the branching ratios of two-body nonleptonic weak decays using the factorization hypothesis in self-consistent CLFQM. We also compare our results with those of other theoretical studies.

    hep-phhep-exEPJC(2025)·8 citations
15. 15*

    High-accuracy optical clocks with sensitivity to the fine-structure constant variation based on Sm${}^{10+}$

    Saleh O. Allehabi🇸🇦 · V. A. Dzuba🇦🇺 · V. V. Flambaum🇦🇺

    We identify two metastable excited states in Sm${}^{10+}$ highly charged ion as candidates for high accuracy optical clocks. Several atomic properties relevant to optical clock development are calculated using relativistic many-body methods. This includes energy levels, transition amplitudes, lifetimes, scalar polarizabilities, black body radiation shift, and the sensitivity to the fine structure constant variation. We found that the clock transitions are not sensitive to perturbation, e.g., relative black body radiation shifts are $\sim 10^{-19}$. The enhancement factor for the $\alpha$ variation is $\sim$ 0.8 for one clock transition and $\sim$ 16 for another.

    hep-ph0 citations
16. 16*

    $A_4$ modular invariance and the strong CP problem

    S.T. Petcov🇮🇹 · M. Tanimoto🇯🇵

    We present simple effective theory of quark masses, mixing and CP violation with level $N=3$ ($A_4$) modular symmetry, which provides solution to the strong CP problem without the need for an axion. The vanishing of the strong CP-violating phase $\bar{\theta }$ is ensured by assuming CP to be a fundamental symmetry of the Lagrangian of the theory. The CP symmetry is broken spontaneously by the vacuum expectation value (VEV) of the modulus $\tau$. This provides the requisite large value of the CKM CP-violating phase while the strong CP phase $\bar{\theta }$ remains zero or is tiny. Within the considered framework we discuss phenomenologically viable quark mass matrices with three types of texture zeros, which are realized by assigning both the left-handed and right-handed quark fields to $A_4$ singlets $1$, $1^{\prime }$ and $1^{\prime \prime }$ with appropriate weights. The VEV of $\tau$ is restricted to reproduce the observed CKM parameters. We discuss cases in which the modulus VEV is close to the fixed points $i$, $\omega$ and $i\infty$. In particular, we focus on the VEV of $\tau$, which gives the absolute minima of the supergravity-motivated modular- and CP-invariant potentials for the modulus $\tau$, so called, modulus stabilisation. We present a successful model, which is consistent with the modulus stabilisation close to $\tau =\omega$.

    hep-phEPJC(2024)·32 citations
17. 17*

    Inhomogeneous confinement and chiral symmetry breaking induced by imaginary angular velocity

    Shi Chen🇺🇸 · Kenji Fukushima🇯🇵 · Yusuke Shimada🇯🇵

    We investigate detailed properties of imaginary rotating matter with gluons and quarks at high temperature. Previously, we showed that imaginary rotation induces perturbative confinement of gluons at the rotation center. We perturbatively calculate the Polyakov loop potential and find inhomogeneous confinement above a certain threshold of imaginary angular velocity. We also evaluate the quark contribution to the Polyakov loop potential and confirm that spontaneous chiral symmetry breaking occurs in the perturbatively confined phase.

    hep-phhep-thPLB(2024)·24 citations
18. 18*

    Magnetic axion vortex and very light QCD axions

    Deog Ki Hong🇰🇷 · Stephen J. Lonsdale🇰🇷

    We show that a stable vortex soliton, carrying a constant magnetic flux, exists in the homogeneous medium of axions with a constant time-derivative. Axions can be bound in the vortex, having energy less than the axion mass. If the observed magnetic fields in galaxies are those of the vortex, the axion-photon coupling has to be smaller than $10^{-17}\mathrm{Ge}{\mathrm{V}}^{-1}$. Otherwise, axions decay too quickly to constitute dark matter in galaxies.

    hep-phastro-ph.GAhep-th0 citations
19. 19*

    Flavour bounds on axions, hidden photons and sterile neutrinos

    Martin Bauer🇬🇧

    Flavour-violating decays are some of the most sensitive probes for New Physics with masses below the B meson threshold. In this talk I review the sensitivity to axion-like particles, hidden photons and heavy neutral leptons assuming minimal models where these are the only particle in addition to the Standard Model, respectively.

    hep-ph0 citations
20. 20*

    Optimised observables and new physics prospects in the penguin-mediated decays $B_{d(s)}\to K^{(\ast )0}\varphi$

    Aritra Biswas🇪🇸 · Sébastien Descotes-Genon🇫🇷 · Joaquim Matias🇪🇸 · Gilberto Tetlalmatzi-Xolocotzi🇩🇪

    We study penguin-mediated ${\bar{B}}_{d(s)}\to {\bar{K}}^{\ast 0}(K^{\ast 0})\varphi$ transitions, proposing a new optimised observable $L_{K^{\ast }\varphi }$ from the ratio of the corresponding branching ratios of these decays, with limited hadronic uncertainties and enhanced New Physics sensitivity. It deviates by $1.48\sigma$ between its experimental value and SM determination within QCD factorisation. This can be accommodated together with significant deviations found in the $K^{(\ast )}{\bar{K}}^{(\ast )}$ modes in our earlier works if New Physics affects either the QCD penguin operator $Q_4$ or the chromomagnetic dipole operator $Q_{8g}$ for both $b\to d$ and $b\to s$ transitions. The allowed range for the Wilson coefficients $C_{4s,8gs}$ is narrower than $C_{4d,8gd}$ since the $b\to s$ transition channel ${\bar{B}}_d\to {\bar{K}}^{\ast 0}\varphi$ is in better agreement with the SM. However, if we add the measured ${\bar{B}}_d\to {\bar{K}}^0\varphi$ branching ratio, simultaneous explanation of all experimental data for $K^{(\ast )}{\bar{K}}^{(\ast )}$ and $K^{\ast }({\bar{K}}^{(\ast )})\varphi$ channels in terms of New Physics in $C_{4d,s}$ or $C_{8gd,s}$ only, is not possible. They can be explained more easily if we assume New Physics in both $f=d,s$ sectors. The addition of the branching ratios of the charged modes $B^{-}\to K^{(\ast )-}\varphi$ to the above mix of observables results in a reduction of the parameter space for the $(C_{4f},C_{6f})$ scenario, while discarding the $(C_{6f},C_{8gf})$ scenario completely. This is because of the discrepancy of more than 1 $\sigma$ between the experimental measurements of the branching ratios of the ${\bar{B}}_d(B^{-})\to {\bar{K}}^0(K^{-})\varphi$ transitions. This provides a strong incentive for the LHCb/Belle II experiments to measure the branching ratios of ${\bar{B}}_d\to {\bar{K}}^{(\ast )0}\varphi$, ${\bar{B}}_s\to K^{\ast 0}\varphi$ and particularly $B^{-}\to K^{-}\varphi$ to confirm or dismiss the conclusions hinted at by present data.

    hep-phhep-exhep-latJHEP(2024)·8 citations
21. 21*

    Nonfactorizable charming-loop contribution to FCNC $B_s\to \gamma l^{+}{l}^{-}$ decay

    Ilia Belov🇮🇹 · Alexander Berezhnoy🇷🇺 · Dmitri Melikhov🇷🇺

    We present the first theoretical calculation of nonfactorizable charm-quark loop contributions to the $B_s\to \gamma l^{+}{l}^{-}$ amplitude. We calculate the relevant form factors, $H_{A,V}^{\mathrm{NF}}(k^{\prime 2},k^2)$, and provide convenient parametrizations of our results in the form of fit functions of two variables, $k^{\prime 2}$ and $k^2$, applicable in the region below hadron resonances, $k^{\prime 2}<M_{J/\psi }^2$ and $k^2<M_{\varphi }^2$. We report that factorizable and nonfactorizable charm contributions to the $B_s\to \gamma l^{+}{l}^{-}$ amplitude have opposite signs. To compare the charm and the top contributions, it is convenient to express the NF charming loop contribution as a non-universal (i.e., dependent on the reaction) $q^2$-dependent correction ${\Delta }^{\mathrm{NF}}{C}_7(q^2)$ to the Wilson coefficient $C_7$. For the $B_s\to \gamma l^{+}{l}^{-}$ amplitude, the correction is found to be positive, ${\Delta }^{\mathrm{NF}}{C}_7(q^2)/C_7>0$.

    hep-phPRD(2024)·5 citations
22. 22*

    Mass Spectra of Full-Heavy and Double-Heavy Tetraquark States in the Conventional Quark Model

    Qi Meng🇨🇳 · Guang-Juan Wang🇯🇵 · Makoto Oka🇯🇵

    A comprehensive study of the $S$-wave heavy tetraquark states with identical quarks and antiquarks, specifically $QQ{\bar{Q}}^{\prime }{\bar{Q}}^{\prime }$ ($Q,Q^{\prime }=c,b$), $QQ\bar{s}\bar{s}$/$\bar{Q}\bar{Q}ss$, and $QQ\bar{q}\bar{q}$/$\bar{Q}\bar{Q}qq$ ($q=u,d$), are studied in a unified constituent quark model. This model contains the one-gluon exchange and confinement potentials. The latter is modeled as the sum of all two-body linear potentials. We employ the Gaussian expansion method to solve the full four-body Schrödinger equations, and search bound and resonant states using the complex-scaling method. We then identify $3$ bound and $62$ resonant states. The bound states are all $QQ\bar{q}\bar{q}$ states with the isospin and spin-parity quantum numbers $I(J^P)=0(1^{+})$: two bound $bb\bar{q}\bar{q}$ states with the binding energies, 153 MeV and 4 MeV below the $B{B}^{\ast }$ threshold, and a shallow $cc\bar{q}\bar{q}$ state at $-15$ MeV from the $D{D}^{\ast }$ threshold. The deeper $bb\bar{q}\bar{q}$ bound state aligns with the lattice QCD predictions, while $cc\bar{q}\bar{q}$ bound state, still has a much larger binding energy than the recently observed $T_{cc}^{+}$ by LHCb collaboration. No bound states are identified for the $QQ{\bar{Q}}^{\prime }{\bar{Q}}^{\prime }$, $QQ\bar{s}\bar{s}$ and $QQ\bar{q}\bar{q}$ with $I=1$. Our analysis shows that the bound $QQ{\bar{Q}}^{\prime }{\bar{Q}}^{\prime }$ states are more probable with a larger mass ratio, $m_Q/m_{Q^{\prime }}$. Experimental investigation for these states is desired, which will enrich our understanding of hadron spectroscopy and probe insights into the confinement mechanisms within tetraquarks.

    hep-phhep-exhep-latPRD(2025)·18 citations
23. 23*

    Searching for enhancement in coalescence of in-jet (anti-)deuterons in proton-proton collisions

    Yoshini Bailung🇮🇳 · Neha Shah🇮🇳 · Ankhi Roy🇮🇳

    Recent measurements from ALICE report that $‘‘$in-jet'' nucleons carry a higher probability of forming a deuteron via coalescence than the nucleons from the underlying event (UE). This study makes use of an event shape classifier to separate the $‘‘$in-jet'' deuterons and the deuterons in the UE produced in high multiplicity proton-proton collisions at $\sqrt{s}=13$ TeV. Event shape variables such as transverse spherocity allow the categorization of hard and soft components of an event, which can be divided into two respective classes; $‘‘$jetty'' and $‘‘$isotropic''. The $‘‘$jetty'' deuterons minus the contribution of the deuterons from the $‘‘$isotropic'' event are taken as $‘‘$in-jet'' deuterons, and the coalescence mechanism is tested. The coalescence is performed with a Wigner function formalism, augmented as an afterburner to \textsc{pythia}8. The possible enhancement of the coalescence probability of $‘‘$in-jet'' deuterons is investigated by calculating the coalescence parameter ($B_2$) in different spherocity classes in high-multiplicity $pp$ collisions.

    hep-phPRC(2024)·5 citations
24. 24*

    Potential of light-cone sum rules without semiglobal quark-hadron duality

    A. Carvunis🇮🇹 · F. Mahmoudi🇫🇷 · Y. Monceaux🇫🇷

    This work addresses the calculation of local form factors involved in the theoretical predictions of semileptonic $B$-meson decays at low $q^2$. We present a new approach to the method of QCD light-cone sum rule with $B$-meson light-cone distribution amplitudes. In our strategy, we bypass the semiglobal quark-hadron duality (QHD) approximation which usually contributes an unknown and potentially large systematic error to the prediction of form factors. We trade this improvement for an increased reliance on higher-order contributions in perturbation theory. Unlike the systematic error from semiglobal QHD, truncation errors are assessable and systematically improvable, hence allowing robust predictions of form factors. For the transitions $B\to \pi ,\rho ,K^{(\ast )}$, our predictions agree with the literature for all form factors at $q^2=0$.

    hep-phPRD(2024)·7 citations
25. 25*

    Analysis of Hadronic Weak Decays of Charmed Baryons in the Topological Diagrammatic Approach

    Huiling Zhong🇨🇳 · Fanrong Xu🇨🇳 · Hai-Yang Cheng🇹🇼

    We perform a global fit to the experimental data of two-body charmed baryon decays based on the topological diagrammatic approach (TDA) and take into account the phase shifts between $S$- and $P$-wave amplitudes as inspired by the recent BESIII measurement of the decay asymmetry in the decay ${\Lambda }_c^{+}\to {\Xi }^0{K}^{+}$. The TDA has the advantage that it is more intuitive, graphic and easier to implement model calculations. The measured branching fractions and decay asymmetries are well accommodated in the TDA except for a few modes, in particular, the predicted $\mathcal{B}({\Xi }_c^0\to {\Xi }^{-}{\pi }^{+})=(2.83\pm 0.10)\%$ is larger than its current value. The equivalence of the TDA and the irreducible SU(3) approach (IRA) is established. We show that the number of the minimum set of tensor invariants in the IRA and the topological amplitudes in the TDA is the same and present their relations. The predicted magnitudes of $S$- and $P$-wave amplitudes and their phase shifts are presented for measured and yet-to-be-measured modes in both the TDA and IRA which can be tested in the near future. Besides the decay ${\Lambda }_c^{+}\to {\Xi }^0{K}^{+}$, there exist several modes which proceed only through $W$-exchange. In particular, the observed channel ${\Xi }_c^0\to {\Sigma }^{+}{K}^{-}$ should have phase shifts similar to that in ${\Lambda }_c^{+}\to {\Xi }^0{K}^{+}$ and its decay asymmetry is predicted to be $-0.21\pm 0.17$ which can be used to test our theoretical framework. In contrast, the TDA leads to a large $\alpha$ of order $-0.93$ for the decay ${\Xi }_c^{+}\to {\Xi }^0{\pi }^{+}$ even after the phase-shift effect is incorporated in the fit.

    hep-phhep-exPRD(2024)·29 citations
26. 26*

    SMEFT Matching to $Z^{\prime }$ Models at Dimension-8

    Sally Dawson🇺🇸 · Matthew Forslund🇺🇸 · Marvin Schnubel🇺🇸

    Heavy neutral gauge bosons arise in many motivated models of Beyond the Standard Model Physics. Experimental searches require that such gauge bosons are above the TeV scale in most models which means that the tools of effective field theories, in particular the Standard Model Effective Field Theory (SMEFT), are useful. We match the SMEFT to models with heavy $Z^{\prime }$ bosons, including effects of dimension-8 operators, and consider the restrictions on model parameters from electroweak precision measurements and from Drell Yan invariant mass distributions and forward-backward asymmetry, $A_{\text{FB}}$, measurements at the LHC. The results demonstrate the model dependence of the resulting limits on SMEFT coefficients and the relatively small impact of including dimension-8 matching. In all cases, the limits from invariant mass distributions are stronger than from $A_{\text{FB}}$ measurements in the $Z^{\prime }$ models we consider.

    hep-phPRD(2024)·28 citations
27. 27*

    Constraints on Dark Matter from Dynamical Heating of Stars in Ultrafaint Dwarfs. Part 2: Substructure and the Primordial Power Spectrum

    Peter W. Graham🇺🇸 · Harikrishnan Ramani🇺🇸

    There is a large and growing interest in observations of small-scale structure in dark matter. We propose a new way to probe dark matter structures in the $\sim 10-10^8{M}_{\odot }$ range. This allows us to constrain the primordial power spectrum over shorter distances scales than possible with direct observations from the CMB. For $k$ in the range $\sim 10-1000{\mathrm{Mpc}}^{-1}$ our constraints on the power spectrum are orders of magnitude stronger than previous bounds. We also set some of the strongest constraints on dark matter isocurvature perturbations. Our method relies on the heating effect such dark matter substructures would have on the distribution of stars in an ultra-faint dwarf galaxy. Many models of inflation produce enhanced power at these short distance scales and can thus be constrained by our observation. Further, many dark matter models such as axion dark matter, self-interacting dark matter and dissipative dark matter, produce dense structures which could be constrained this way.

    hep-phastro-ph.COastro-ph.GAPRD(2024)·53 citations
28. 28*

    Inferring flavor mixtures in multijet events

    Ezequiel Alvarez🇦🇷 · Yuling Yao🇺🇸

    Multijet events with heavy-flavors are of central importance at the LHC since many relevant processes -- such as $t\bar{t}$, $hh$, $t\bar{t}h$ and others -- have a preferred branching ratio for this final state. Current techniques for tackling these processes use hard-assignment selections through $b$-tagging working points, and suffer from systematic uncertainties because of the difficulties in Monte Carlo simulations. We develop a flexible Bayesian mixture model approach to simultaneously infer $b$-tagging score distributions and the flavor mixture composition in the dataset. We model multidimensional jet events, and to enhance estimation efficiency, we design structured priors that leverages the continuity and unimodality of the $b$-tagging score distributions. Remarkably, our method eliminates the need for a parametric assumption and is robust against model misspecification -- It works for arbitrarily flexible continuous curves and is better if they are unimodal. We have run a toy inferential process with signal $bbbb$ and backgrounds $bbcc$ and $cccc$, and we find that with a few hundred events we can recover the true mixture fractions of the signal and backgrounds, as well as the true $b$-tagging score distribution curves, despite their arbitrariness and nonparametric shapes. We discuss prospects for taking these findings into a realistic scenario in a physics analysis. The presented results could be a starting point for a different and novel kind of analysis in multijet events, with a scope competitive with current state-of-the-art analyses. We also discuss the possibility of using these results in general cases of signals and backgrounds with approximately known continuous distributions and/or expected unimodality.

    hep-phhep-exstat.APSciPost Phys.Core(2024)·4 citations
29. 29*

    Electrical conductivity of hot relativistic plasma in a strong magnetic field

    Ritesh Ghosh🇺🇸 · Igor A. Shovkovy🇺🇸

    We employ first-principles quantum field theoretical methods to investigate the longitudinal and transverse electrical conductivities of a strongly magnetized hot quantum electrodynamics (QED) plasma at the leading order in coupling. The analysis employs the fermion damping rate in the Landau-level representation, calculated with full kinematics and exact amplitudes of one-to-two and two-to-one QED processes. In the relativistic regime, both conductivities exhibit an approximate scaling behavior described by ${\sigma }_{\parallel ,\perp }=T{\tilde{\sigma }}_{\parallel ,\perp }$, where ${\tilde{\sigma }}_{\parallel ,\perp }$ are functions of the dimensionless ratio $|eB|/T^2$ (with $T$ denoting temperature and $B$ magnetic field strength). We argue that the mechanisms for the transverse and longitudinal conductivities differ significantly, leading to a strong suppression of the former in comparison to the latter.

    hep-phhep-thnucl-thPRD(2024)·15 citations
30. 30*

    Testing an oscillatory behavior of dark energy

    Luis A. Escamilla🇬🇧 · Supriya Pan🇮🇳 · Eleonora Di Valentino🇬🇧 · Andronikos Paliathanasis🇿🇦 · J. Alberto Vázquez🇲🇽 · Weiqiang Yang🇨🇳

    The main aim of this work is to use a model-independent approach, along with late-time observational probes, to reconstruct the dark energy (DE) equation of state $w_{\mathrm{DE}}(z)$. Our analysis showed that, for a late time universe, $w_{\mathrm{DE}}$ deviates from being a constant but in contrast exhibits an oscillatory behavior, hence both quintessence ($w_{\mathrm{DE}}>-1$) and phantom ($w_{\mathrm{DE}}<-1$) regimes are equally allowed. In order to portray this oscillatory behavior, we explored various parametrizations for the equation of state and identified the closest approximation based on the goodness of fit with the data and the Bayesian evidence analysis. Our findings indicated that while all considered oscillating DE parametrizations provided a better fit to the data, compared to the cosmological constant, they are penalized in the Bayesian evidence analysis due to the additional free parameters. Overall, the present article demonstrates that in the low redshift regime, the equation of state of the DE prefers to be dynamical and oscillating. We anticipate that future cosmological probes will take a stand in this direction.

    ↳ astro-ph.COgr-qchep-phPRD(2025)·33 citations
31. 31*

    Thermal production of charm quarks in relativistic heavy-ion collisions

    Taesoo Song🇩🇪 · Ilia Grishmanovskii🇩🇪 · Olga Soloveva🇩🇪 · Elena Bratkovskaya🇩🇪

    We investigate the thermal production of charm quarks in the strongly interacting quark-gluon plasma (sQGP) created in heavy-ion collisions at relativistic energies. Our study is based on the off-shell parton-hadron-string dynamics (PHSD) transport approach describing the full time evolution of heavy-ion collisions on a microscopic basis with hadronic and partonic degrees of freedom. The sQGP is realized within the effective dynamical quasi-particle model (DQPM) which is adjusted to reproduce the lattice QCD results for the thermodynamic observables of the sQGP. Relying on the fact that the DQPM successfully describes the spatial diffusion coefficients $D_s$ from the lQCD, which control the interaction of charm quarks with thermal partons (expressed in terms of strongly interacting off-shell quasiparticles), we evaluate the production of charm quark pairs through the rotation of Feynman diagrams such that the incoming charm quark and outgoing light parton in elastic scattering diagrams are exchanged. The charm quark annihilation is realized by detailed balance. We find that the number of produced thermal charm quark pairs strongly depends on the charm quark mass in the QGP. While for the heavy charm quarks of mass $m_c=1.8$ GeV it is subdominant compared to the primary charm production by binary nucleon-nucleon collisions at RHIC and LHC energies, the numbers of primary and thermal charm quarks become comparable for a smaller (bare) $m_c=1.2$ GeV. Compared with the experimental data on the $R_{\mathrm{AA}}$ of $D$-mesons in heavy-ion collisions at RHIC and LHC energies, it is more favorable for charm quarks in the QGP to gain additional mass due to thermal effects rather than to have a low bare mass.

    ↳ nucl-thhep-phnucl-exPRC(2024)·14 citations
32. 32*

    Primordial Black Holes from Spatially Varying Cosmological Constant Induced by Field Fluctuations in Extra Dimensions

    Arkady A. Popov🇷🇺 · Sergey G. Rubin🇷🇺 · Alexander S. Sakharov🇺🇸

    The origin and evolution of supermassive black holes (SMBHs) in our universe have sparked controversy. In this study, we explore the hypothesis that some of these black holes may have seeded from the direct collapse of dark energy domains with density significantly higher than the surrounding regions. The mechanism of the origin of such domains relies on the inflationary evolution of a scalar field acting in D dimensions, which is associated with the cosmological constant in our four-dimensional spacetime manifold. Inner space quantum fluctuations of the field during inflation are responsible for the spatial variations of the dark energy density in our space. This finding holds particular significance, especially considering recent evidence from pulsar timing array observations, which supports the existence of a stochastic gravitational wave background consisting of SMBH mergers.

    ↳ astro-ph.COgr-qchep-phhep-thUniverse(2024)·1 citation
33. 33*

    Coordinate versus momentum cuts and effects of collective flow on critical fluctuations

    Volodymyr A. Kuznietsov🇺🇦 · Mark I. Gorenstein🇺🇦 · Volker Koch🇺🇸 · Volodymyr Vovchenko🇺🇸

    We analyze particle number fluctuations in the crossover region near the critical endpoint of a first-order phase transition by utilizing molecular dynamics simulations of the classical Lennard-Jones fluid. We extend our previous study [V.A. Kuznietsov et al., Phys. Rev. C 105, 044903 (2022)] by incorporating longitudinal collective flow. The scaled variance of particle number distribution inside different coordinate and momentum space acceptances is computed through ensemble averaging and found to agree with earlier results obtained using time averaging, validating the ergodic hypothesis for fluctuation observables. Presence of a sizable collective flow is found to be essential for observing large fluctuations from the critical point in momentum space acceptances. We discuss our findings in the context of heavy-ion collisions.

    ↳ nucl-thhep-phPRC(2024)·10 citations
34. 34*

    Prospects of nuclear-coupled-dark-matter detection via correlation spectroscopy of I${}_2^{+}$ and Ca${}^{+}$

    Eric Madge🇮🇱 · Gilad Perez🇮🇱 · Ziv Meir🇮🇱

    The nature of dark matter (DM) and its interaction with the Standard Model (SM) is one of the biggest open questions in physics nowadays. The vast majority of theoretically-motivated Ultralight-DM (ULDM) models predict that ULDM couples dominantly to the SM strong/nuclear sector. This coupling leads to oscillations of nuclear parameters that are detectable by comparing clocks with different sensitivities to these nature's constants. Vibrational transitions of molecular clocks are more sensitive to a change in the nuclear parameters than the electronic transitions of atomic clocks. Here, we propose the iodine molecular ion, I${}_2^{+}$, as a sensitive detector for such a class of ULDM models. The iodine's dense spectrum allows us to match its transition frequency to that of an optical atomic clock (Ca${}^{+}$) and perform correlation spectroscopy between the two clock species. With this technique, we project a few-orders-of-magnitude improvement over the most sensitive clock comparisons performed to date. We also briefly consider the robustness of the corresponding "Earth-bound" under modifications of the $Z_N$-QCD axion model.

    ↳ physics.atom-phhep-phPRD(2024)·23 citations
35. 35*

    Stringy constraints on primordial electromagnetic fields in axion inflation

    Hajime Otsuka🇯🇵 · Ryo Yokokura🇯🇵

    We study primordial electromagnetic fields in effective actions of string theory. In contrast to a conventional scenario of producing primordial electromagnetic fields induced by the axion inflation, we deal with the Dirac-Born-Infeld action as a non-linear generation of Maxwell theory. It turns out that the intensity of generated electromagnetic fields is bounded from above by the string scale which can also be rewritten in terms of supersymmetry breaking scale in the context of type IIB Large Volume Scenario. The instability parameter $\xi$ is constrained by the tadpole cancellation condition of D3-branes and a realization of hierarchy between the string scale and the Hubble scale of inflation. Hence, the magnetogenesis can be realized in the limited corner of the string landscape due to the $\mathcal{O}(1)$ value of the coefficient of Chern-Simons coupling.

    ↳ hep-thastro-ph.COhep-phJHEP(2024)·1 citation
36. 36*

    Dark photon constraints from a 7.139 GHz cavity haloscope experiment

    Dong He🇨🇳 · Jie Fan🇨🇳 · Xin Gao🇨🇳 · Yu Gao🇨🇳 · Nick Houston🇨🇳 · Zhongqing Ji🇨🇳 · Yirong Jin🇨🇳 · Chuang Li🇨🇳 · Jinmian Li🇨🇳 · Tianjun Li🇨🇳 · Shi-hang Liu🇨🇳 · Jia-Shu Niu🇨🇳 and 14 other authors

    The dark photon is a promising candidate for the dark matter which comprises most of the matter in our visible Universe. Via kinetic mixing with the Standard Model it can also be resonantly converted to photons in an electromagnetic cavity, offering novel experimental possibilities for the discovery and study of dark matter. We report the results of a pathfinder dark photon dark matter cavity search experiment performed at Hunan Normal University and the Institute of Physics, Chinese Academy of Sciences, representing the first stage of the APEX (Axion and dark Photon EXperiment) program. Finding no statistically significant excess, we place an upper limit on the kinetic mixing parameter $|\chi |<3.7\times 10^{-13}$ around $m_A\simeq 29.5$ $\mu$eV at 90% confidence level. This result exceeds other constraints on dark photon dark matter in this frequency range by roughly an order of magnitude.

    ↳ hep-exhep-phPRD(2024)·15 citations
37. 37*

    Dianoga SIDM: galaxy cluster self-interacting dark matter simulations

    Antonio Ragagnin🇮🇹 · Massimo Meneghetti🇮🇹 · Francesco Calura · Giulia Despali · Klaus Dolag🇩🇪 · Moritz S. Fischer🇩🇪 · Carlo Giocoli🇮🇹 · Lauro Moscardini🇮🇹

    This work aims at assessing the impact of DM self-interactions on the properties of galaxy clusters. In particular, the goal is to study the angular dependence of the cross section by testing rare (large angle scattering) and frequent (small angle scattering) SIDM models with velocity-dependent cross sections. We re-simulate six galaxy cluster zoom-in initial conditions with a dark matter only run and with a full-physics setup simulations that includes a self-consistent treatment of baryon physics. We test the dark matter only setup and the full physics setup with either collisionless cold dark matter, rare self-interacting dark matter, and frequent self-interacting dark matter models. We then study their matter density profiles as well as their subhalo population. Our dark matter only SIDM simlations agree with theoretical models, and when baryons are included in simulations, our SIDM models substantially increase the central density of galaxy cluster cores compared to full-physics simulations using collisionless dark matter. SIDM subhalo suppression in full-physics simulations is milder compared to the one found in dark matter only simulations, because of the cuspier baryionic potential that prevent subhalo disruption. Moreover SIDM with small-angle scattering significantly suppress a larger number of subhaloes compared to large angle scattering SIDM models. Additionally, SIDM models generate a broader range of subhalo concentration values, including a tail of more diffuse subhaloes in the outskirts of galaxy clusters and a population of more compact subhaloes in the cluster cores.

    ↳ astro-ph.COastro-ph.GAhep-phAstron.Astrophys.(2024)·34 citations
38. 38*

    Signals for invisible matter from solar-terrestrial observations

    M. Maroudas🇬🇷

    The composition of the dark universe although hypothesised, remains one of the biggest mysteries in modern physics. On smaller scales, there are various solar puzzling phenomena which known physics cannot explain like the coronal heating problem, the origin of sunspots, the trigger mechanism of solar flares, but also the open issue since the 1850's on the planetary impact of the active Sun. At the same time, several terrestrial observations in the dynamic Earth's atmosphere such as the ionospheric ionisation around December are unexpected within conventional physics. Following this work, the suggested common solution of all these conventionally unexplained phenomena is based on an external triggering caused by low-speed streaming constituents from the dark sector, being gravitationally focused or deflected by the Sun and the orbiting planets. Evidence in support of this hypothesis and on the existence of one or more streams or clusters has been provided based on a coincidence analysis of long-term astrophysical and planetary datasets. Of note, the planetary correlation is the novel key signature. Finally, a redefined strategy for direct Dark Matter searches focused on streaming Dark Matter is proposed. This novel procedure has been successfully implemented in the CAST-CAPP detector at CERN searching for Dark Matter axions.

    ↳ hep-exastro-ph.EPastro-ph.IMhep-ph5 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.