Tue·Jul 19, 2022Tuesday·July 19, 2022

1. 01*

   Jets in evolving matter within the opacity expansion approach

   Andrey V. Sadofyev🇪🇸 · Matthew D. Sievert🇺🇸 · Ivan Vitev🇺🇸

   In a recent study [1] we have extended the opacity expansion approach to describe jet-medium interactions including medium motion effects in the context of heavy-ion collisions. We have computed color field of the in-medium sources, including the effects of the transverse field components and the energy transfer between the medium and jet. The corresponding contributions are sub-eikonal in nature, and were previously ignored in the literature. Here we discuss how our approach can be applied to describe the medium motion effects in the context of Deep Inelastic Scattering.

   hep-phnucl-thSciPost Phys.Proc.(2022)·10 citations
2. 02*

   Isovector Meson Masses from QCD Sum Rules

   Nasrallah F. Nasrallah🇱🇧 · Karl Schilcher🇩🇪

   We present a calculation of the masses of the isovector mesons ( vector, scalar and pseudoscalar including the established recurrences) using a new method of finite energy QCD sum rules. The method is based on the idea of choosing a suitable integration kernel which minimizes the occurring integral over the cut in the complex energy (squared) plane. We obtain remarkably stable results in a wide range R, where R is the radius of the integration contour. The sum rule predictions agree with the experimental values within the expected accuracy showing that QCD describes single resonances.

   hep-phMod.Phys.Lett.A(2023)·0 citations
3. 03*

   Portals into Higgs vacuum stability

   Gudrun Hiller🇩🇪 · Tim Höhne🇩🇪 · Daniel F. Litim🇬🇧 · Tom Steudtner🇩🇪

   We address the notorious metastability of the standard model (SM) and promote it to a model building task: What are the new ingredients required to stabilize the SM up to the Planck scale without encountering subplanckian Landau poles? Using the SM extended by vector-like fermions (VLFs), we chart out the corresponding landscape of Higgs stability. We find that the gauge portal mechanism, triggered by new SM charge carriers, opens up sizeable room for stability in a minimally invasive manner. We also find models with Higgs criticality, and Yukawa portals opening up at stronger coupling. Several models allow for VLFs in the TeV-range, which can be searched for at the LHC. For nontrivial flavor structure severe flavor-changing neutral current constraints arise which complement those from stability, and push lower fermion masses up to $\mathcal{O}(10^3\text{TeV})$.

   hep-phhep-thPRD(2022)·34 citations
4. 04*

   The study of nonstrange quark stars within a modified NJL model

   Cheng-Ming Li🇨🇳 · Shu-Yu Zuo🇨🇳 · Ya-Peng Zhao🇨🇳 · Hui-Jun Mu🇨🇳 · Yong-Feng Huang🇨🇳

   In this work, a modified Nambu-Jona-Lasinio (NJL) model with proper-time regularization is employed to study the structure of nonstrange quark stars. The coupling constant of four-fermion interaction in the conventional NJL model is modified as $G=G_1+G_2⟨\bar{\psi }\psi ⟩$ to highlight the feedback of quark propagator to gluon propagator. To study the dependence of the equation of state (EOS) on this modification as well as the vacuum pressure, we choose nine representative EOSs for comparison. It is found that a smaller $G_1$ leads to a stiffer EOS, and a higher vacuum pressure (i.e., a smaller bag constant) yields a softer EOS at low energy density. It is further shown that the heaviest quark star under this modified NJL model satisfies not only the recent mass measurement of PSR J0740+6620, but also the radius constraints from X-ray timing observations. The corresponding tidal deformability is also in agreement with the observations of GW170817.

   hep-phPRD(2022)·13 citations
5. 05*

   Far-from-equilibrium kinetic dynamics of $\lambda {\varphi }^4$ theory in an expanding universe

   Nicki Mullins (Illinois U., Urbana)🇺🇸 · Gabriel S. Denicol (Niteroi, Fluminense U.)🇧🇷 · Jorge Noronha (Illinois U., Urbana)🇺🇸

   We investigate the far-from-equilibrium behavior of the Boltzmann equation for a gas of massless scalar field particles with quartic (tree level) self-interactions ($\lambda {\varphi }^4$) in Friedmann-Lemaitre-Robertson-Walker spacetime. Using a new covariant generating function for the moments of the Boltzmann distribution function, we analytically determine a subset of the spectrum and the corresponding eigenfunctions of the linearized Boltzmann collision operator. We show how the covariant generating function can be also used to find the exact equations for the moments in the full nonlinear regime. Different than the case of a ultrarelativistic gas of hard spheres (where the total cross section is constant), for $\lambda {\varphi }^4$ the fact that the cross section decreases with energy implies that moments of arbitrarily high order directly couple to low order moments. Numerical solutions for the scalar field case are presented and compared to those found for a gas of hard spheres.

   hep-phgr-qcnucl-thPRD(2022)·18 citations
6. 06*

   Nuclear Modification Factor in Small System Collisions within Perturbative QCD Including Thermal Effects

   L.S. Moriggi🇧🇷 · M.V.T. Machado🇧🇷

   In this paper, dedicated to the memory of the late Prof. Jean Cleymans, the nuclear modification factors, $R_{xA}$, are investigated for pion production in small system collisions, measured by PHENIX experiment at RHIC (Relativistic Heavy Ion Collider). The theoretical framework is the transverse momentum $k_T$-factorization formalism for hard processes at small momentum fraction, $x$. Evidence for collective expansion and thermal effects for pions, produced at equilibrium, is studied based on phenomenological parametrization of blast-wave type in the relaxation time approximation. The dependencies on the centrality and on the projectile species are discussed in terms of the behavior of Cronin peak and the suppression of $R_{xA}$ at large transverse momentum, $p_T$. The multiplicity of produced particles, which is sensitive to the soft sector of the spectra, is also included in the present analysis.

   hep-phhep-exnucl-exMDPI Physics(2022)·4 citations
7. 07*

   The 3-loop anomalous dimensions from off-shell operator matrix elements

   J. Blümlein🇩🇪 · P. Marquard🇩🇪 · C. Schneider🇦🇹 · K. Schönwald🇩🇪

   We report on the calculation of the three-loop polarized and unpolarized flavor non-singlet and the polarized singlet anomalous dimensions using massless off-shell operator matrix elements in a gauge-variant framework. We also reconsider the unpolarized two-loop singlet anomalous dimensions and correct errors in the foregoing literature.

   hep-phhep-exhep-thPoS(2022)·8 citations
8. 08*

   Analysis of the $X(6600)$, $X(6900)$, $X(7300)$ and related tetraquark states with the QCD sum rules

   Zhi-Gang Wang🇨🇳

   In this work, we re-investigate the mass spectrum of the ground state, first, second and third radial excited states of the diquark-antidiquark type fully-charm tetraquark states with the QCD sum rules plus Regge trajectories. We take account of the CMS and ATLAS experimental data and preform a self-consistent analysis, then try to make possible assignments of the $X(6600)$, $X(6900)$ and $X(7300)$ in the picture of tetraquark states with the $J^{PC}=0^{++}$ or $1^{+-}$.

   hep-phNPB(2022)·53 citations
9. 09*

   Gravitational waves and neutrino oscillations in Chern-Simons axion gravity

   Gaetano Lambiase🇮🇹 · Leonardo Mastrototaro🇮🇹 · Luca Visinelli🇨🇳

   We investigate the modifications in the neutrino flavor oscillations under the influence of a stochastic gravitational wave background (SGWB), in a scenario in which General Relativity is modified by an additional Chern-Simons (CS) term. Assuming that the dark matter halo is in the form of axions, the CS coupling modifies the pattern of the neutrino flavor oscillations at Earth up to a total suppression in some frequency range. At the same time, the SGWB in the halo could stimulate the axion decay into gravitons over a narrow frequency range, leading to a potentially detectable resonance peak in the enhanced SGWB strain. A consistent picture would require these features to potentially show up in neutrino detection from supernovae, gravitational wave detectors, and experiments aimed at the search for axions in the Milky Way halo.

   hep-phastro-ph.COastro-ph.GAgr-qcJCAP(2023)·29 citations
10. 10*

    Simulation analysis with rock muons from atmospheric neutrino interactions in the ICAL detector at INO

    R. Kanishka🇮🇳 · D. Indumathi🇮🇳 · Lakshmi S. Mohan🇵🇱 · V. Bhatnagar🇮🇳

    The proposed magnetized Iron CALorimeter detector (ICAL) to be built in the India-based Neutrino Observatory (INO) laboratory aims to study atmospheric neutrinos and its properties such as precision measurements of oscillation parameters and the neutrino mass hierarchy. High energy charged current (CC) interactions of atmospheric neutrinos with the rock surrounding the detector produce so-called "rock muons" along with hadrons. While the hadron component of these events are absorbed in the rock itself, the rock muons traverse the rock and are detected in the detector. These rock muon events can be distinguished from cosmic muons only in the upward direction and can provide an independent measurement of the oscillation parameters. A simulation study of these events at the ICAL detector shows that, although reduced in significance compared to muons produced in direct CC neutrino interactions with the detector, these events are indeed sensitive to the oscillation parameters, achieving a possible $1\sigma$ precision of 10\% and 27\% in determining $\Delta m_{32}^2$ and ${\sin }^2{\theta }_{23}$, respectively. Hence a combination of the standard atmospheric neutrino analysis which is the main goal of ICAL, with these rock muon events, will improve the precision reach of ICAL for these parameters.

    hep-phphysics.ins-detEPJC(2023)·0 citations
11. 11*

    S.M.A.S.H.E.D.: Standard Model Axion Seesaw Higgs Inflation Extended for Dirac Neutrinos

    Maximilian Berbig🇩🇪

    Inspired by the S.M.A.S.H. framework we construct a model that addresses the strong CP problem, axion dark matter, inflation and Dirac neutrino masses as well as leptogenesis. The model possesses only two dynamical scales, namely the SM breaking scale $v_H$ and the Peccei Quinn (PQ) breaking scale $v_{\sigma }$. We introduce heavy vector-like quarks in the usual KSVZ fashion to implement the PQ mechanism for the strong CP problem. To generate neutrino masses via a dimension six operator scaling as $m_{\nu }\sim v_H^3/v_{\sigma }^2$ we add heavy triplet and doublet leptons, which are vector-like under the SM but chiral under PQ symmetry. The model is free from the cosmological domain wall problem and predicts an axion to photon coupling which is about an order of magnitude larger than in conventional DFSZ and KSVZ models. Thus our scenario can be probed and potentially excluded by current and next generation axion experiments such as ORGAN or MADMAX. In addition we numerically demonstrate that our construction can generate the observed baryon asymmetry by realizing a version of the Dirac-Leptogenesis scenario. As a consequence of our neutrino mass mechanism we find that the asymmetry in triplet fermion decays can also be significantly enhanced by up to six orders of magnitude when compared to typical Seesaw scenarios without needing to invoke a resonant enhancement. In passing we note that a decaying Dirac fermion with multiple decay modes contains all the necessary ingredients required for the \enquote{quasi optimal efficiency}-scenario previously encountered in the context decaying scalar triplets. The impact of the right handed neutrinos and the axion on $\Delta N_{\text{eff}}$ is estimated and lies within current bounds.

    hep-phJCAP(2022)·21 citations
12. 12*

    Parker Bound and Monopole Pair Production from Primordial Magnetic Fields

    Takeshi Kobayashi🇮🇹 · Daniele Perri🇮🇹

    We present new bounds on the cosmic abundance of magnetic monopoles based on the survival of primordial magnetic fields during the reheating and radiation-dominated epochs. The new bounds can be stronger than the conventional Parker bound from galactic magnetic fields, as well as bounds from direct searches. We also apply our bounds to monopoles produced by the primordial magnetic fields themselves through the Schwinger effect, and derive additional conditions for the survival of the primordial fields.

    hep-phastro-ph.COhep-thPRD(2022)·24 citations
13. 13*

    Gauged $U(1{)}_{L_{\mu }-L_{\tau }}$ Symmetry and two-zero Textures of Inverse Neutrino Mass Matrix in light of Muon ($g-2$)

    Labh Singh🇮🇳 · Monal Kashav🇮🇳 · Surender Verma🇮🇳

    In the framework of anomaly free $U(1{)}_{L_{\mu }-L_{\tau }}$ model, charged scalar fields give rise to massive gauge boson ($Z_{\mu \tau }$) through spontaneous symmetry breaking. $Z_{\mu \tau }$ leads to one loop contribution to the muon anomalous magnetic moment. These scalar fields may, also, appear in the structure of right-handed neutrino mass matrix, thus, connecting the possible explanation of muon ($g-2$) and low energy neutrino phenomenology through $vevs$ associated with the scalar fields. In the present work, we consider textures of inverse neutrino mass matrix ($M_{\nu }^{-1}$) wherein any two elements of the mass matrix are zero. In this ansatz, with Dirac neutrino mass matrix diagonal, the zero(s) of right-handed Majorana neutrino mass matrix correspond to zero(s) in the low energy effective neutrino mass matrix (within Type-I seesaw). We have realized two such textures of $M_{\nu }^{-1}$ accommodating the muon ($g-2$) and low energy neutrino phenomenology. The requirement of successful explanation of muon ($g-2$), further, constrain the allowed parameter space of the model and results in sharp correlations amongst neutrino mixing angles, $CP$ invariants and effective Majorana mass ($M_{ee}$). The model explains muon ($g-2$) for $M_{Z_{\mu \tau }}$ in the range ($0.035$ GeV-$0.100$ GeV) and $g_{\mu \tau }\approx \mathcal{O}(10^{-4}$) which is found to be consistent with constraints coming from the experiments like CCFR, COHERENT, BABAR, NA62 and NA64.

    hep-phMod.Phys.Lett.A(2022)·9 citations
14. 14*

    Note on the definitions of branching ratios of overlapping resonances

    V. Burkert🇺🇸 · V. Crede🇺🇸 · E. Klempt🇩🇪 · K.V. Nikonov🇩🇪 · J. A. Oller🇪🇸 · J. R. Peláez🇪🇸 · J. Ruiz de Elvira🇪🇸 · A.V. Sarantsev🇩🇪 · L. Tiator🇩🇪 · U. Thoma🇩🇪 · R. Workman🇺🇸

    Branching ratios for the decay of hadrons with large width or near thresholds depend on their definition. We test different definitions and show that rather different branching ratios can be obtained. For wide resonances and for sequential decays with wide intermediate resonances, integration over the spectral functions is mandatory. The tests are performed exploiting the latest solution of the Bonn-Gatchina multi-channel analysis and published values for residues of light scalar mesons. For a resonance overlapping with a threshold, in case its pole lies in a non-adjacent sheet, we show how the total width, needed for the branching ratios, does not correspond to the imaginary part of the pole position. We use the Madrid-Krakow dispersive parameterizations to illustrate this situation with the $f_0(980)$.

    hep-phPLB(2023)·18 citations
15. 15*

    The $X(3960)$ seen in $D_s^{+}{D}_s^{-}$ as the $X(3930)$ state seen in $D^{+}{D}^{-}$

    M. Bayar🇹🇷 · A. Feijoo🇪🇸 · E. Oset🇪🇸

    We perform a calculation of the interaction of the $D\bar{D}$, $D_s{\bar{D}}_s$ coupled channels and find two bound states, one coupling to $D\bar{D}$ and another one at higher energies coupling mostly to $D_s^{+}{D}_s^{-}$. We identify this latter state with the $X_0(3930)$ seen in the $D^{+}{D}^{-}$ mass distribution in the $B^{+}\to D^{+}{D}^{-}{K}^{+}$ decay, and also show that it produces an enhancement of the $D_s^{+}{D}_s^{-}$ mass distribution close to threshold which is compatible with the LHCb recent observation in the $B^{+}\to D_s^{+}{D}_s^{-}{K}^{+}$ decay which has been identified as a new state, $X_0(3960)$.

    hep-phnucl-thPRD(2023)·35 citations
16. 16*

    Liénard-Wiechert potential of a heavy quark moving in QGP medium

    Jobin Sebastian🇮🇳 · Mohammad Yousuf Jamal🇮🇳 · Najmul Haque🇮🇳

    We investigate the nature of the complex retarded potential of a heavy quarkonium moving in a hot and dense static deconfined nuclear medium. The well-known concept of the retarded potential in electrodynamics is extended to the context of the heavy-quark by modifying the static vacuum Cornell potential through Lorentz transformation to the static frame of the medium. The resulting potential in the vacuum is further corrected to incorporate the screening effect offered by the thermal medium. To do so, the retarded Cornell potential is modified by the dielectric function of the static quark-gluon plasma (QGP) medium. We present the numerical results for the real and imaginary parts of the potential along with the analytical expression of the potential approximated by a small velocity limit. Finally, we present the thermal width of quarkonia in the QGP medium derived using the imaginary part of the potential and study its dependence on velocity and temperature.

    hep-phnucl-thPRD(2023)·16 citations
17. 17*

    Delving into new physics in semileptonic $b\to c\tau \bar{\nu }$ transitions

    Aishwarya Bhatta🇮🇳 · Rukmani Mohanta🇮🇳

    Recently, several indications of lepton non-universality observables have been perceived in semileptonic $B$ meson decay processes, both in the neutral-current ($b\to sll$) and charged-current ($b\to cl{\bar{\nu }}_l$) transitions. Influenced by these fascinating quotients, we examine the semileptonic decays involving the $b\to cl{\bar{\nu }}_l$ quark level transitions. We execute it through a model independent analysis in order to probe the nature of new physics. Taking into consideration the most general effective Hamiltonian, we scrutinize ${\Lambda }_b\to {\Lambda }_c\tau {\bar{\nu }}_{\tau }$, $B_c^{+}\to {\eta }_c{\tau }^{+}{\nu }_{\tau }$, and $B\to D^{\ast \ast }\tau {\bar{\nu }}_{\tau }$ (where $D^{\ast \ast }=\{D_0^{\ast },D_1^{\ast },D_1,D_2^{\ast }\}$ are the four lightest excited charm mesons) processes, in the presence of new physics. We perform a global fit to different sets of new coefficients, making use of the measurements on $R_D$, $R_{D^{\ast }}$, $R_{J/\psi }$, $P_{\tau }^{D^{\ast }}$ and the upper limit on Br($B_c^{+}\to {\tau }^{+}{\nu }_{\tau }$). We then inspect the effect of constrained new couplings on the branching ratios, forward-backward asymmetry parameters, lepton non-universality ratios (LNU), lepton and hadron polarization asymmetries of these decay modes.

    hep-phSciPost Phys.Proc.(2025)·3 citations
18. 18*

    Exotic molecular meson states of $B^{(\ast )}{K}^{(\ast )}$ nature

    E. Oset🇪🇸 · L.Roca🇪🇸

    We evaluate theoretically the interaction of the open bottom and strange systems $\bar{B}\bar{K}$, ${\bar{B}}^{\ast }\bar{K}$, $\bar{B}{\bar{K}}^{\ast }$ and ${\bar{B}}^{\ast }{\bar{K}}^{\ast }$ to look for possible bound states which could correspond to exotic non--quark-antiquark mesons since they would contain at least one $b$ and one $s$ quarks. The s-wave scattering matrix is evaluated implementing unitarity by means of the Bethe-Salpeter equation, with the potential kernels obtained from contact and vector meson exchange mechanisms. The vertices needed are supplied from Lagrangians derived from suitable extensions of the hidden gauge symmetry approach to the bottom sector. We find poles below the respective thresholds for isospin 0 interaction and evaluate the widths of the different obtained states by including the main sources of imaginary part, which are the $B^{\ast }\to B\gamma$ decay in the ${\bar{B}}^{\ast }\bar{K}$ channels, the $K^{\ast }\to K\pi$ in the channels involving a $K^{\ast }$, plus the box diagrams with $\bar{B}\bar{K}$ and ${\bar{B}}^{\ast }\bar{K}$ intermediate states for the ${\bar{B}}^{\ast }{\bar{K}}^{\ast }$ channels.

    hep-phEPJC(2022)·10 citations
19. 19*

    A $U$-Spin Anomaly in Charm CP Violation

    Stefan Schacht🇬🇧

    Recent LHCb data shows that the direct CP asymmetries of the decay modes $D^0\to {\pi }^{+}{\pi }^{-}$ and $D^0\to K^{+}{K}^{-}$ have the same sign, violating an improved $U$-spin limit sum rule in an unexpected way at $2.1\sigma$. From the new data, we determine for the first time the imaginary part of the CKM-subleading, $U$-spin breaking $\Delta U=1$ correction to the $U$-spin limit $\Delta U=0$ amplitude. The imaginary part of the $\Delta U=0$ amplitude is determined by $\Delta a_{CP}^{\mathrm{dir}}$. The corresponding strong phases are yet unknown and could be extracted in the future from time-dependent measurements. Assuming $\mathcal{O}(1)$ strong phases due to non-perturbative rescattering, we find the ratio of $U$-spin breaking to $U$-spin limit contributions to the CKM-subleading amplitudes to be $(173_{-74}^{+85})\%$. This highly exceeds the Standard Model (SM) expectation of $\sim 30\%$ $U$-spin breaking, with a significance of $1.95\sigma$. If this puzzle is confirmed with more data in the future, in the SM it would imply the breakdown of the $U$-spin expansion in CKM-subleading amplitudes of charm decays. The other solution are new physics models that generate an additional $\Delta U=1$ operator, leaving the $U$-spin power expansion intact. Examples for the latter option are an extended scalar sector or flavorful $Z^{\prime }$ models.

    hep-phhep-exJHEP(2023)·41 citations
20. 20*

    Renormalization of three-quark operators at two loops in the RI${}^{\prime }$/SMOM scheme

    Bernd A. Kniehl🇩🇪 · Oleg L. Veretin🇩🇪

    We consider the renormalization of the three-quark operators without derivatives at next-to-next-to-leading order in QCD perturbation theory at the symmetric subtraction point. This allows us to obtain conversion factors between the $\overline{\mathrm{MS}}$ scheme and the regularization invariant symmetric MOM (RI/SMOM, RI${}^{\prime }$/SMOM) schemes. The results are presented both analytically in $R_{\xi }$ gauge in terms of a set of master integrals and numerically in Landau gauge. They can be used to reduce the errors in determinations of baryonic distribution amplitudes in lattice QCD simulations.

    hep-phhep-latNPB(2023)·5 citations
21. 21*

    Establishing the heavy quark spin and light flavor molecular multiplets of the $X(3872)$, $Z_c(3900)$ and $X(3960)$

    Teng Ji🇨🇳 · Xiang-Kun Dong🇨🇳 · Miguel Albaladejo🇪🇸 · Meng-Lin Du🇪🇸 · Feng-Kun Guo🇨🇳 · Juan Nieves🇪🇸

    Recently, the LHCb Collaboration reported a near-threshold enhancement, $X(3960)$, in the $D_s^{+}{D}_s^{-}$ invariant mass distribution. We show that the data can be well described by either a bound or a virtual state below the $D_s^{+}{D}_s^{-}$ threshold. The mass given by the pole position is $(3928\pm 3)$ MeV. Using this mass and the existing information on the $X(3872)$ and $Z_c(3900)$ resonances, a complete spectrum of the $S$-wave hadronic molecules formed by a pair of ground state charmed and anticharmed mesons is established. Thus, pole positions of the partners of the $X(3872)$, $Z_c(3900)$ and the newly observed $D_s^{+}{D}_s^{-}$ state are predicted. Calculations have been carried out at the leading order of nonrelativistic effective field theory and considering both heavy quark spin and light flavor SU(3) symmetries, though conservative errors from the breaking of these symmetries are provided.

    hep-phhep-exhep-latPRD(2022)·53 citations
22. 22*

    The translational $\mu$-$\tau$ reflection symmetry of Majorana neutrinos

    Zhi-zhong Xing🇨🇳

    The present neutrino oscillation data allow $m_1^{}=0$ (or $m_3^{}=0$) for the neutrino mass spectrum and support ${\theta }_{23}^{}\simeq \pi /4$ and $\delta \simeq -\pi /2$ as two good approximations for the PMNS lepton flavor mixing matrix $U$. We show that these intriguing possibilities can be a very natural consequence of the {\it translational} $\mu$-$\tau$ reflection symmetry -- the effective Majorana neutrino mass term keeps invariant under the transformations ${\nu }_{e\mathrm{L}}^{}\to ({\nu }_{e\mathrm{L}}^{}{)}^c+U_{ei}^{\ast }{z}_{\nu }^c$, ${\nu }_{\mu \mathrm{L}}^{}\to ({\nu }_{\tau \mathrm{L}}^{}{)}^c+U_{\tau i}^{\ast }{z}_{\nu }^c$ and ${\nu }_{\tau \mathrm{L}}^{}\to ({\nu }_{\mu \mathrm{L}}^{}{)}^c+U_{\mu i}^{\ast }{z}_{\nu }^c$ (for $i=1$ or $3$), where $z_{\nu }^c$ is the charge conjugation of a constant spinor field $z_{\nu }^{}$. Extending such a working flavor symmetry to the canonical seesaw mechanism at a superhigh-energy scale, we calculate its soft breaking effects at the electroweak scale by using the one-loop renormalization-group equations.

    hep-phInt.J.Mod.Phys.A(2023)·4 citations
23. 23*

    EOS -- A Software for Flavor Physics Phenomenology

    Méril Reboud🇩🇪

    I present EOS, an open-source software dedicated to a variety of tasks in the processing of flavor physics observables. EOS is written in C++ and offers both a C++ and a Python interface. It is developed for three main tasks, the production of theoretical predictions for flavor physics observables; the inference of theoretical parameters from an extensible database of likelihoods; and the production of Monte Carlo samples of flavor processes for sensitivity studies.

    hep-phPoS(2021)·0 citations
24. 24*

    Muon ($g-2$) and W-boson mass Anomaly in a Model Based on $Z_4$ Symmetry with Vector like Fermion

    Simran Arora🇮🇳 · Monal Kashav🇮🇳 · Surender Verma🇮🇳 · B.C. Chauhan🇮🇳

    The latest results of CDF-II collaboration show a discrepancy of $7\sigma$ with standard model expectations. There is, also, a $4.2\sigma$ discrepancy in the measurement of muon magnetic moment reported by Fermilab. We study the connection between neutrino masses, dark matter, muon ($g-2$) and W-boson mass anomaly within a single coherent framework based on $Z_4$ extension of the scotogenic model with vector like lepton (VLL). Neutrino masses are generated at one loop level. The inert doublet, also, provide a solution to W-boson mass anomaly through correction in oblique parameters $S$, $T$ and $U$. The coupling of VLL triplet ${\psi }_T$ to inert doublet $\eta$ provides positive contribution to muon anomalous magnetic moment. In the model, the VLL triplet provides a lepton portal to dark matter (${\eta }_R^0$). The model predicts a lower bound $m_{ee}>0.025$ eV at 3$\sigma$, which is well within the sensitivity reach of the $0\nu \beta \beta$ decay experiments. The model explains muon anomalous magnetic moment $\Delta a_{\mu }$ for $1.3<y_{\psi }<2.8$ and mass of DM candidate in the range $152\text{ GeV}<M_{{\eta }_R^0}<195\text{ GeV}$. The explanation of W-boson mass anomaly, further, constrain the mass of DM candidate, $M_{{\eta }_R^0}$, in the range $154\text{ GeV}<M_{{\eta }_R^0}<174\text{ GeV}$.

    hep-phPTEP(2022)·9 citations
25. 25*

    Differential N${}^3$LO QCD corrections to charged current production at the LHC

    Xuan Chen🇩🇪 · Thomas Gehrmann🇨🇭 · Nigel Glover🇬🇧 · Alexander Huss🇨🇭 · Tong-Zhi Yang🇨🇭 · Hua Xing Zhu🇨🇳

    Charged current Drell-Yan production at hadron colliders is a benchmark electroweak process. A recent measurement of the W boson mass by the CDF experiment displays a large deviation from the Standard Model prediction. To enable precision phenomenology for this process, we compute the third-order (N${}^3$LO) QCD corrections to the rapidity distribution in W boson production and to the transverse mass distribution of its decay products. We study kinematic regions relevant for the LHC experiments and assess the numerical magnitude of uncertainties from electroweak input parameters and parton distribution functions.

    hep-phhep-exPoS(2022)·5 citations
26. 26*

    Decay behaviors of the fully-bottom and fully-charm tetraquark states

    Hua-Xing Chen🇨🇳 · Yi-Xin Yan🇨🇳 · Wei Chen🇨🇳

    We study the decay behaviors of the fully-bottom tetraquark states within the diquark-antidiquark picture, and calculate their relative branching ratios through the Fierz rearrangement. Our results suggest that the $C=+$ states can be searched for in the ${\mu }^{+}{\mu }^{-}{\rm Y}(1S)$ and ${\mu }^{+}{\mu }^{-}{\rm Y}(2S)$ channels with the relative branching ratio $\mathcal{B}(X\to \mu \mu {\rm Y}(2S))/\mathcal{B}(X\to \mu \mu {\rm Y}(1S))\approx 0.4$. Our results also suggest that the $C=-$ states can be searched for in the ${\mu }^{+}{\mu }^{-}{\eta }_b(1S)$ and ${\mu }^{+}{\mu }^{-}{\eta }_b(2S)$ channels with the similar relative branching ratio $\mathcal{B}(X\to \mu \mu {\eta }_b(2S))/\mathcal{B}(X\to \mu \mu {\eta }_b(1S))\approx 0.4$. We also reanalysis the fully-charm tetraquark states, and study the $X(6900)$ decay into the $J/\psi \psi (2S)$ channel to obtain the relative branching ratio $\mathcal{B}(X\to J/\psi \psi (2S))/\mathcal{B}(X\to J/\psi J/\psi )\approx 0.1$.

    hep-phhep-exPRD(2022)·30 citations
27. 27*

    Annual modulation of event rate and electron recoil energy in inelastic scattering direct detection experiments

    Amin Aboubrahim🇩🇪 · Lutz Althueser🇩🇪 · Michael Klasen🇩🇪 · Pran Nath🇺🇸 · Christian Weinheimer🇩🇪

    In 2020 the XENON1T experiment observed an excess of events with an electron recoil energy $E_R$ in the range of $2$--$3$keV. Such an excess can arise from a variety of sources such as solar axions or a neutrino magnetic moment, but also from inelastic scattering of dark matter off the xenon atoms. The recoil energy of the electron then depends on the mass difference of the dark particles. In this paper we show that the annual modulation of both the event rate and the electron recoil energy provide important additional information that allows to distinguish among different theoretical explanations of the signal. To this end, we first extend the formalism of annual modulation to electronic recoils, inelastic dark matter scattering and the electron recoil energy. We then study a concrete theoretical model with two Dirac fermions and a dark photon. We take into account all relevant cosmological and experimental constraints on this model and apply it to the XENON1T and and XENONnT experiments with realistic detection thresholds, efficiencies and energy resolutions, fitting the main physical parameters of the model, i.e. the mass splitting and the electron scattering cross section. The discriminatory power of the additional information from the annual modulation of both the signal rate and the electron recoil energy is then demonstrated for XENONnT with a simplified model based on these main physical parameters. This more sensitive procedure compared to time-only modulation analyses can also serve as a template for other theoretical models with different dark matter candidates, mediators and cosmology. For the $U(1)$ model with two Dirac fermions fitting the XENON1T excess and the experimental conditions of XENONnT, taking into account the annual variation of the signal rate and recoil energy allows for a faster and more precise determination of the free model parameters.

    hep-ph4 citations
28. 28*

    Probing the electromagnetic properties of the ${\Sigma }_c^{(\ast )}{D}^{(\ast )}$-type doubly charmed molecular pentaquarks

    Hong-Yan Zhou🇨🇳 · Fu-Lai Wang🇨🇳 · Zhan-Wei Liu🇨🇳 · Xiang Liu🇨🇳

    In this work, we discuss the electromagnetic properties of the $S$-wave ${\Sigma }_c^{(\ast )}{D}^{(\ast )}$-type doubly charmed molecular pentaquarks, which have close relation to their inner structures. Both the $S$-$D$ wave mixing effect and the coupled channel effect are taken into account. We analyze the magnetic moments for the $S$-wave ${\Sigma }_c^{(\ast )}{D}^{(\ast )}$ molecular states, and extend our theoretical framework to study the transition magnetic moments and the radiative decay widths between the $S$-wave ${\Sigma }_c^{(\ast )}{D}^{(\ast )}$ molecules. We discuss the relations between the magnetic moments and the transition magnetic moments for the $S$-wave ${\Sigma }_c^{(\ast )}{D}^{(\ast )}$-type doubly charmed molecular pentaquarks, which can be regarded as an indirect way to measure their magnetic moments experimentally. The present study may inspire experimentalist's interest in measuring the electromagnetic properties of the hadronic molecular states.

    hep-phhep-exPRD(2022)·23 citations
29. 29*

    Supersizing axions with small size instantons

    Alexey Kivel🇩🇪 · Julien Laux🇩🇪 · Felix Yu🇩🇪

    We construct a new framework to calculate the enhancement of axion masses and concomitant effects on axion-meson mixing arising from small size instantons (SSIs), which originate in models featuring an extended color gauge symmetry. The framework is based on an explicit evaluation of 't Hooft determinantal operators that partition into instanton amplitudes, affording a more precise determination of the axion-diphoton coupling than previous results. Using an explicit model first presented in Ref. arXiv:1805.06465, we demonstrate that axions solving the strong CP problem can have electroweak scale masses and higher, driven by SSI effects. Such collider axions are prime targets for resonance searches at the Large Hadron Collider and afford a unique anchor for motivating extended color symmetries.

    hep-phJHEP(2022)·26 citations
30. 30*

    Leading Order Triple Collinear Splitting Functions Revisited

    Oscar Braun-White🇬🇧

    I review the factorisation properties of tree level amplitudes when three particles $i$, $j$, $k$ are collinear. The triple collinear splitting functions contain both iterated single unresolved contributions, and genuine double unresolved contributions. I make this explicit by rewriting the known triple collinear splitting functions for a quark and two gluons in terms of products of two-particle splitting functions, and a remainder that is explicitly finite when any two of $\{i,j,k\}$ are collinear.

    hep-phPoS(2022)·0 citations
31. 31*

    Beyond dimension six in SM Effective Field Theory: a case study in Higgs pair production at NLO QCD

    Gudrun Heinrich🇩🇪 · Jannis Lang🇩🇪 · Ludovic Scyboz🇬🇧

    We present the NLO (two-loop) QCD corrections to Higgs boson pair production in gluon fusion within Standard Model Effective Theory (SMEFT), including also squared dimension-6 operators and double insertions of operators. The different options to truncate the EFT expansion are contrasted to a non-linear EFT approach (HEFT) and their effects are illustrated by several phenomenological examples.

    hep-phPoS(2022)·4 citations
32. 32*

    Inflating and Reheating the Universe with an Independent Affine Connection

    Alberto Salvio🇮🇹

    It is shown that a component of the dynamical affine connection, which is independent of the metric, can drive inflation in agreement with observations. This provides a geometrical origin for the inflaton. It is also found that the decays of this field, which has spin 0 and odd parity, into Higgs bosons can reheat the universe up to a sufficiently high temperature.

    hep-phastro-ph.COgr-qchep-thPRD(2022)·46 citations
33. 33*

    Classical vs quantum corrections to jet broadening in a weakly-coupled Quark-Gluon Plasma

    Jacopo Ghiglieri🇫🇷 · Eamonn Weitz🇫🇷

    The transverse momentum broadening coefficient $\hat{q}$ receives both soft, classical and radiative, quantum corrections. The former are responsible for a large O(g) correction, whereas the latter enter at relative order ${\alpha }_s$, but are enhanced by a double logarithm of the length of the medium over the thermal wavelength. We analyze radiative corrections for a weakly-coupled quark-gluon plasma. We find that a thermal population of dynamical gluons changes the boundaries and reduces the size of the double-logarithmic phase space. It also provides new subdominant logarithmic corrections. We also show how the quantum, double-logarithmic and classical, soft phase spaces are smoothly connected once the radiated gluon becomes soft enough. Finally, we discuss a pathway to a determination of radiative corrections beyond the harmonic-oscillator approximation.

    hep-phnucl-thJHEP(2022)·28 citations
34. 34*

    The Diagrammatic Coaction

    Samuel Abreu🇨🇭 · Ruth Britto🇮🇪 · Claude Duhr🇩🇪 · Einan Gardi🇬🇧 · James Matthew🇬🇧

    The diagrammatic coaction underpins the analytic structure of Feynman integrals, their cuts and the differential equations they admit. The coaction maps any diagram into a tensor product of its pinches and cuts. These correspond respectively to differential forms defining master integrals, and integration contours which place a subset of the propagators on shell. In a canonical basis these forms and contours are dual to each other. In this talk I review our present understanding of this algebraic structure and its manifestation for dimensionally-regularized Feynman integrals that are expandable to polylogarithms around integer dimensions. Using one- and two-loop integral examples, I will explain the duality between forms and contours, and the correspondence between the local coaction acting on the Laurent coefficients in the dimensional regulator and the global coaction acting on generalised hypergeometric functions.

    ↳ hep-thhep-phPoS(2022)·6 citations
35. 35*

    Mimetic Curvaton

    Xin-zhe Zhang🇨🇳 · Lei-hua Liu🇨🇳 · Taotao Qiu🇨🇳

    In this paper, we investigate the primordial perturbations of inflation model induced from the multi-field mimetic gravity, where there are two field during inflation, and thus both adiabatic and isocurvature perturbation modes are generated. We show that although it is true that the original adiabatic perturbation mode loses the kinetic term due to the constraint equation, by applying the curvaton mechanism where one of the field is viewed as curvaton field, the adiabatic perturbation can actually be transferred from the isocurvature one at the end of inflation. Detailed calculations are performed for both inflationary and the consequent matter-dominant epochs. Therefore, the so-called "non-propagating problem" of the adiabatic mode will actually do no harm to the multi-field mimetic inflation models.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2023)·14 citations
36. 36*

    Gravitational and Dilatonic Radiations from the Parallel Dressed-Dynamical Unstable Dp-Branes

    Hamidreza Daniali🇮🇷 · Davoud Kamani🇮🇷

    In the context of the bosonic string theory, we shall extract the general radiation amplitude of a massless closed string from the interaction of two parallel unstable D$p$-branes. The branes are non-stationary and have been dressed by background fields. The foregoing amplitude will be rewritten for the massless state radiation from the branes with the large distance. Besides, we shall study the gravitational and dilatonic radiations from this configuration.

    ↳ hep-thhep-phAnnals Phys.(2022)·4 citations
37. 37*

    Explicit Diffeomorphism Breaking, No-go Conditions, and the Gravity Sector of the SME

    Robert Bluhm🇺🇸

    A brief recap is given of issues that can occur when fixed nondynamical backgrounds that explicitly break diffeomorphism invariance are included in gravity theories. Implications for the Standard-Model Extension (SME) are summarized, including recent results showing how the SME can be modified to accommodate such fixed nondynamical backgrounds.

    ↳ hep-thgr-qchep-ph0 citations
38. 38*

    First Constraints on Heavy QCD Axions with a Liquid Argon Time Projection Chamber using the ArgoNeuT Experiment

    ArgoNeuT Collaboration: R. Acciarri🇺🇸 · C. Adams🇺🇸 · B. Baller🇺🇸 · V. Basque🇺🇸 · F. Cavanna🇺🇸 · R. T. Co🇺🇸 · R. S. Fitzpatrick🇺🇸 · B. Fleming🇺🇸 · P. Green🇬🇧 · R. Harnik🇺🇸 · K. J. Kelly🇨🇭 · S. Kumar🇺🇸 and 12 other authors

    We present the results of a search for heavy QCD axions performed by the ArgoNeuT experiment at Fermilab. We search for heavy axions produced in the NuMI neutrino beam target and absorber decaying into dimuon pairs, which can be identified using the unique capabilities of ArgoNeuT and the MINOS near detector. This decay channel is motivated by a broad class of heavy QCD axion models that address the strong CP and axion quality problems with axion masses above the dimuon threshold. We obtain new constraints at a 95\% confidence level for heavy axions in the previously unexplored mass range between 0.2-0.9 GeV, for axion decay constants around tens of TeV.

    ↳ hep-exhep-phPRL(2023)·25 citations
39. 39*

    Computer Algebra and Hypergeometric Structures for Feynman Integrals

    Johannes Bluemlein🇩🇪 · Marco Saragnese🇩🇪 · Carsten Schneider🇦🇹

    We present recent computer algebra methods that support the calculations of (multivariate) series solutions for (certain coupled systems of partial) linear differential equations. The summand of the series solutions may be built by hypergeometric products and more generally by indefinite nested sums defined over such products. Special cases are hypergeometric structures such as Appell-functions or generalizations of them that arise frequently when dealing with parameter Feynman integrals.

    ↳ math-phcs.SChep-phmath.MPPoS(2022)·2 citations
40. 40*

    Signals from the Early Universe: Black Holes, Gravitational Waves and Particle Physics

    Valerio De Luca🇨🇭

    We dedicate this thesis to the study of signatures coming from the primordial epochs of the universe. We will focus in particular on Primordial Black Holes (PBHs), which may be formed from perturbations generated during inflation and might comprise a fraction of the dark matter in the universe. In the first part of the thesis, we will address the PBH properties at the time of formation, that are their masses, spins and abundance, and investigate the generation of Gravitational Wave (GW) signals during their production. In the second part, we will describe the PBHs evolution across the cosmic history due to their assemble in binaries, phases of baryonic mass accretion and clustering effects. We will then discuss GW signatures coming from their coalescence, compare these predictions with present GW data detected by the LIGO/Virgo Collaboration (LVC) and assess the role of future GW experiments like 3G detectors and LISA in discovering these objects. Finally, in the third part, we will investigate some aspects of the interplay between black holes and fundamental physics in the early universe, focusing on the role of GWs to shed light on their properties.

    ↳ astro-ph.COgr-qchep-phhep-th4 citations
41. 41*

    Dark Energy and Extending the Geodesic Equations of Motion: A Spectrum of Galactic Rotation Curves

    Achilles D. Speliotopoulos

    A recently proposed extension of the geodesic equations of motion, where the worldline traced by a test particle now depends on the scalar curvature, is used to study the formation of galaxies and galactic rotation curves. This extension is applied to the motion of a fluid in a spherical geometry, resulting in a set of evolution equations for the fluid in the nonrelativistic and weak gravity limits. Focusing on the stationary solutions of these equations and choosing a specific class of angular momenta for the fluid in this limit, we show that dynamics under this extension can result in the formation of galaxies with rotational velocity curves (RVC) that are consistent with the Universal Rotation Curve (URC), and through previous work on the URC, the observed rotational velocity profiles of 1100 spiral galaxies. In particular, a spectrum of RVCs can form under this extension, and we find that the two extreme velocity curves predicted by it brackets the ensemble of the URCs constructed from these 1100 velocity profiles. We also find that the asymptotic behavior of the URC is consistent with that of the most probable asymptotic behavior of the RVCs predicted by the extension. A stability analysis of these stationary solutions is also done, and we find them to be stable in the galactic disk, while in the galactic hub they are stable if the period of oscillations of perturbations is longer than $0.91_{\pm 0.31}$ to $1.58_{\pm 0.46}$ billion years.

    ↳ gr-qcastro-ph.COastro-ph.GAhep-ph+1Gen.Rel.Grav.(2022)·0 citations
42. 42*

    Effective shear and bulk viscosities of the quark-gluon plasma: QCD versus heavy-ion data

    Fernando G. Gardim🇧🇷 · Jean-Yves Ollitrault🇫🇷

    In recent years, there has been a significant effort to extract the temperature-dependent shear ($\eta /s$) and bulk ($\zeta /s$) viscosity over entropy ratios of the quark-gluon plasma from a global comparison of heavy-ion data with results of hydrodynamic simulations. However, anisotropic flow, which is arguably the most sensitive probe of viscosity, is only sensitive to an {\it effective\/} viscosity over entropy ratio, which is obtained by taking a weighted average over the temperature, and summing the contributions of shear and bulk. We estimate this effective viscosity using existing first-principles calculations, which give $0.17<(\eta /s{)}_{\mathrm{eff}}<0.21$, and $(\zeta /s{)}_{\mathrm{eff}}<0.08$, implying that the damping of anisotropic flow at the LHC is mostly due to shear viscosity. The values extracted from global data analyses are compatible with these theory predictions.

    ↳ nucl-thhep-phnucl-exActa Phys.Polon.Supp.(2023)·3 citations
43. 43*

    Stability and instability of strange dwarfs

    Francesco Di Clemente (Ferrara University and INFN Sez. Ferrara)🇮🇹 · Alessandro Drago (Ferrara University and INFN Sez. Ferrara)🇮🇹 · Prasanta Char (STAR Institute, University of Liege)🇧🇪 · Giuseppe Pagliara (Ferrara University and INFN Sez. Ferrara)🇮🇹

    More than 20 years ago, Glendenning, Kettner and Weber proposed the existence of stable white dwarfs with a core of strange quark matter. More recently, by studying radial modes, Alford, Harris and Sachdeva concluded instead that those objects are unstable. We aim to clarify this issue. We investigate the stability of these objects by looking at their radial oscillations while incorporating boundary conditions at the quark-hadron interface, corresponding to either a rapid or a slow conversion of hadrons into quarks. Our analysis shows that objects of this type are stable if the star is not strongly perturbed, and ordinary matter cannot transform into strange quark matter because of the Coulomb barrier separating the two components. On the other hand, ordinary matter can be transformed into strange quark matter if the star undergoes a violent process, as in the preliminary stages of a type Ia supernova, and this causes the system to become unstable and to collapse into a strange quark star. In this way, accretion-induced collapse of strange dwarfs can be facilitated, and km-sized objects with subsolar masses can be produced.

    ↳ astro-ph.SRastro-ph.HEhep-phnucl-thAstron.Astrophys.(2023)·16 citations
44. 44*

    On the robustness of solitons crystals in the Skyrme model

    Gonzalo Barriga🇨🇱 · Fabrizio Canfora🇨🇱 · Marcela Lagos🇨🇱 · Matías Torres🇨🇱 · Aldo Vera🇨🇱

    In this work we analize how the inclusion of extra mesonic degrees of freedom affect the finite density solitons crystals of the Skyrme model. In particular, the first analytic examples of hadronic crystals at finite baryon density in both the Skyrme $\omega$-mesons model as well as for the Skyrme $\rho$-mesons theory are constructed. These configurations have arbitrary topological charge and describe crystals of baryonic tubes surrounded by a cloud of vector-mesons. In the $\omega$-mesons case, it is possible to reduce consistently the complete set of seven coupled non-linear field equations to just two integrable differential equations; one ODE for the Skyrmion profile and one PDE for the $\omega$-mesons field. This analytical construction allows to show explicitly how the inclusion of $\omega$-mesons in the Skyrme model reduces the repulsive interaction energy between baryons. In the Skyrme $\rho$-mesons case, it is possible to construct analytical solutions using a meron-type ansatz and fixing one of the couplings of the $\rho$-mesons action in terms of the others. We show that, quite remarkably, the values obtained for the coupling constants by requiring the consistency of our ansatz are very close to the values used in the literature to reduce nuclei binding energies of the Skyrme model without vector-mesons. Moreover, our analytical results are in qualitative agreement with the available results on the nuclear spaghetti phase.

    ↳ hep-thastro-ph.HEhep-phnucl-thNPB(2022)·7 citations
45. 45*

    Towards the determination of the gluon helicity distribution in the nucleon from lattice quantum chromodynamics

    Colin Egerer🇺🇸 · Bálint Joó🇺🇸 · Joseph Karpie🇺🇸 · Nikhil Karthik🇺🇸 · Tanjib Khan🇧🇩 · Christopher J. Monahan🇺🇸 · Wayne Morris🇺🇸 · Kostas Orginos🇺🇸 · Anatoly Radyushkin🇺🇸 · David G. Richards🇺🇸 · Eloy Romero🇺🇸 · Raza Sabbir Sufian🇺🇸 · Savvas Zafeiropoulos🇫🇷

    We present the first exploratory lattice quantum chromodynamics (QCD) calculation of the polarized gluon Ioffe-time pseudo-distribution in the nucleon. The Ioffe-time pseudo-distribution provides a frame-independent and gauge-invariant framework to determine the gluon helicity in the nucleon from first principles. We employ a high-statistics computation using a $32^3\times 64$ lattice ensemble characterized by a $358$ MeV pion mass and a $0.094$ fm lattice spacing. We establish the pseudo-distribution approach as a feasible method to address the proton spin puzzle with successive improvements in statistical and systematic uncertainties anticipated in the future. Within the statistical precision of our data, we find a good comparison between the lattice determined polarized gluon Ioffe-time distribution and the corresponding expectations from the state-of-the-art global analyses. We find a hint for a nonzero gluon spin contribution to the proton spin from the model-independent extraction of the gluon helicity pseudo-distribution over a range of Ioffe-time, $\nu \lesssim 9$.

    ↳ hep-lathep-phnucl-thPRD(2022)·50 citations
46. 46*

    Photon generation and entanglement in a double superconducting cavity

    Cruz I. Velasco🇪🇸 · Nicolás F. Del Grosso🇦🇷 · Fernando C. Lombardo🇦🇷 · Alejandro Soba🇦🇷 · Paula I. Villar🇦🇷

    We study the dynamical Casimir effect in a double superconducting cavity in a circuit quantum electrodynamics architecture. Parameters in the quantum circuit are chosen in such a way the superconducting cavity can mimic a double cavity, formed by two perfectly conducting outer walls and a dielectric one, with arbitrary permittivity separating both halves. We undertake a spectral analysis of the cavity, showing that the spectrum varies significantly depending on the values of the susceptibility of the dielectric mirror and the relative lengths of both cavities. We study the creation of photons when the walls oscillate harmonically with a small amplitude. Furthermore, we explore the possibility of entangling two uncoupled cavities, starting from a symmetric double cavity and having both of its halves become uncoupled at a later given instant. We consider both cases: (i) when the field is initially in a vacuum state and (ii) the situation in which photon creation via the dynamical Casimir effect has already taken place. We show that the cavities become entangled in both cases but, in the latter, the quantum correlation between individual modes can be greatly increased at the cost of diminishing the entanglement between most pairs of modes.

    ↳ quant-phcond-mat.otherhep-phPRA(2022)·8 citations
47. 47*

    Unitarizing non-relativistic Coulomb scattering

    J. A. Oller🇪🇸

    We compare the exactly solvable nonrelativistic Coulomb scattering with two recent unitarization methods for infinite-range forces. These methods require to calculate perturbatively the corresponding partial-wave amplitudes, which are then unitarized. We calculate the Coulomb partial-wave amplitudes up to the one-loop order. On the one hand, the unitarization method developed by Refs. [1, 2] reproduces properly the exact solution, with an accuracy improving as the order in the perturbative calculation of the input perturbative partial-wave amplitudes increases. This is also shown to be the case for the pole position of the ground state. On the other hand, the method developed by the more recent Ref. [3] gives rise to partial-wave amplitudes that do not reproduce the known solvable solution, and gives rise to a pole position with zero binding energy.

    ↳ hep-thhep-phPLB(2022)·5 citations
48. 48*

    Unveiling confinement in pure gauge SU(3): flux tubes, fields, and magnetic currents

    M. Baker🇺🇸 · V. Chelnokov🇩🇪 · L. Cosmai🇮🇹 · F. Cuteri🇩🇪 · A. Papa🇮🇹

    A characteristic signature of quark confinement is the concentration of the chromoelectric field between a static quark-antiquark pair in a flux tube. However, the structure of this flux tube, and hence of the confining force, has not been completely understood. Here we perform new lattice measurements of field distributions on smeared Monte Carlo ensembles in SU(3) gauge theory. On the basis of these simulations we demonstrate that the confining force can be understood using the analogy with the basic principles of electromagnetism as elucidated by Maxwell. We derive a chromomagnetic Lorentz force density coupling the chromoelectric field to chromomagnetic currents and integrate this force density over the flux tube interior to obtain a Maxwell-like force that squeezes the flux tube in the transverse direction. We show that the strength of this transverse confining force is equal to the value of the string tension calculated numerically from the chromoelectric field on the midplane between the quarks, verifying the consistency of these two complementary pictures of confinement.

    ↳ hep-lathep-phEPJC(2022)·10 citations
49. 49*

    Two-Loop Infrared Renormalization with On-shell Methods

    Pietro Baratella🇩🇪 · Sara Maggio🇩🇪 · Michael Stadlbauer🇩🇪 · Tobias Theil🇩🇪

    Within the framework proposed by Caron-Huot and Wilhelm, we give a recipe for computing infrared anomalous dimensions purely on-shell, efficiently up to two loops in any massless theory. After introducing the general formalism and reviewing the one-loop recipe, we extract a practical formula that relates two-loop infrared anomalous dimensions to certain two- and three-particle phase space integrals with tree-level form factors of conserved operators. We then provide several examples of the use of the two-loop formula and comment on some of its formal aspects, especially the cancellation of 'one-loop squared' spurious terms. The present version of the paper is augmented with a detailed treatment of the structure of infrared divergences in massless theories of scalars and fermions up to two loops. In the calculation we encounter divergent phase space integrals and show in detail how these cancel among each other as required by the finiteness of the anomalous dimension. As a non-trivial check of the method, we also perform the computation with a standard diagrammatic approach, finding perfect agreement.

    ↳ hep-thhep-phEPJC(2023)·20 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.