Thu·Apr 6, 2023Thursday·April 6, 2023

1. 01*

   Spin-Dependent Interactions and Heavy-Quark Transport in the QGP

   Zhanduo Tang🇺🇸 · Ralf Rapp🇺🇸

   We extend a previously constructed T-matrix approach to the quark-gluon plasma (QGP) to include the effects of spin-dependent interactions between partons. Following earlier work within the relativistic quark model, the spin-dependent interactions figure as relativistic corrections to the Cornell potential. When applied to the vacuum spectroscopy of quarkonia, in particular their mass splittings in S- and P-wave states, the issue of the Lorentz structure of the confining potential arises. We confirm that a significant admixture of a vector interaction (to the previously assumed scalar interaction) improves the description of the experimental mass splittings. The temperature corrections to the in-medium potential are constrained by results from thermal lattice-QCD for the equation of state (EoS) and heavy-quark (HQ) free energy in a selfconsistent set-up for heavy- and light-parton spectral functions in the QGP. We then deploy the refined in-medium heavy-light T-matrix to compute the charm-quark transport coefficients in the QGP. The vector component of the confining potential, through its relativistic corrections, enhances the friction coefficient for charm quarks in the QGP over previous calculations by tens of percent at low momenta and temperatures, and more at higher momenta. Our results are promising for improving the current phenomenology of open heavy-flavor observables at Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC).

   hep-phnucl-thPRC(2023)·18 citations
2. 02*

   3D EMT distributions as an Abel image of 2D EMT distributions on the light-front

   Poonam Choudhary🇮🇳 · Bheemsehan Gurjar🇮🇳 · Dipankar Chakrabarti🇮🇳 · Asmita Mukherjee🇮🇳

   The energy-momentum tensor (EMT) and corresponding gravitational form factors (GFFs) provide us information about the internal structure like spin, mass and spatial densities of the proton. The Druck gravitational (D-term) form factor is related to the mechanical stability of the proton and gives information about the spatial distributions of the forces inside the hadron. In this work, we study the GFFs in the framework of the light-front quark diquark model. The model has been successful to derive various properties of protons. We investigate the three-dimensional spatial distributions of proton as an Abel image of two-dimensional distributions in this model[1]. We explicitly show the global and local stability conditions which are satisfied by both 2D and 3D distributions in our model. We compare our results with the chiral quark soliton model, JLab and lattice data.

   hep-phhep-thContribution to: DIS2022: XXIX Internatio…·1 citation
3. 03*

   Off-shell generalized parton distributions of the pion

   Wojciech Broniowski🇵🇱 · Vanamali Shastry🇵🇱 · Enrique Ruiz Arriola🇪🇸

   We analyze off-shell effects in the generalized parton distributions (GPDs) of the pion in the context of the Sullivan electroproduction process, as well as the corresponding half-off-shell electromagnetic and gravitational form factors. We illustrate our general results within a chiral quark model, where the off-shell effects show up at a significant level, indicating their contribution to uncertainties in the extraction of the GPDs from the future experimental data.

   hep-phhep-exActa Phys.Polon.Supp.(2023)·3 citations
4. 04*

   Strong-field vacuum polarisation with high energy lasers

   A. J. Macleod🇨🇿 · J. P. Edwards🇬🇧 · T. Heinzl🇬🇧 · B. King🇬🇧 · S. V. Bulanov🇨🇿

   When photons propagate in vacuum they may fluctuate into matter pairs thus allowing the vacuum to be polarised. This linear effect leads to charge screening and renormalisation. When exposed to an intense background field a nonlinear effect can arise when the vacuum is polarised by higher powers of the background. This nonlinearity breaks the superposition principle of classical electrodynamics, allowing for light-by-light scattering of probe and background photons mediated through virtual pairs dressed by the background. Vacuum polarisation is a strong-field effect when all orders of interaction between the virtual pair and the background must be taken into account. In this investigation we show that multiple scattering processes of this type may be observed by utilising high-energy laser pulses with long pulse duration, such as are available at facilities like ELI Beamlines. In combination with appropriate sources of high-energy probe photons, multiple probe-background light-by-light scattering allows for testing the genuine nonlinear regime of strong-field QED. This provides access to the uncharted nonperturbative regime beyond the weak-field limit.

   hep-phNew J.Phys.(2023)·17 citations
5. 05*

   Nuclear modification factors for identified hadrons from 5 TeV $p$-Pb collisions and their relation to the Cronin effect

   Thomas A. Trainor🇺🇸

   Nuclear modification factors (NMFs) are spectrum ratios rescaled by an estimate of the number of binary N-N collisions $N_{bin}$ within an A-B collision. NMFs from more-central A-A collisions have been interpreted to indicate formation of a quark-gluon plasma (QGP) when compared with results from control $p$-A or $d$-A collisions. However, subsequent analyses of such control systems are now also interpreted to indicate QGP formation, calling into question proper interpretation of NMFs. An additional complication is the nature of the so-called ``Cronin effect'' contribution to NMF structure that is not well understood. In the present study a two-component model of hadron production (TCM) is applied to identified-hadron (PID) $p_t$ spectra from 5 GeV $p$-Pb collisions extending up to 20 GeV/c. Hard components (jet fragment distributions) are accurately isolated and their evolution with collision centrality parametrized. The TCM is then applied to NMFs without rescaling by $N_{bin}$, allowing direct comparisons between NMF evolution and hard-component evolution with centrality. To address the Cronin effect the TCM is applied to fixed-target $p$-A spectra from the Chicago-Princeton (C-P) collaboration, the origin of the Cronin effect. Inferred C-P spectrum hard components are quantitatively consistent with extrapolation of jet-related structure from higher energies. As a general conclusion spectrum ratios such as NMFs are difficult to interpret, whereas direct differential analysis of isolated spectra may be interpreted simply and accurately.

   hep-ph7 citations
6. 06*

   Gravitational Waves Produced by Domain Walls During Inflation

   Haipeng An🇨🇳 · Chen Yang🇨🇳

   We study the properties of the stochastic gravitational wave background (SGWB) produced by domain walls (DWs) during inflation without forming a network. We numerically simulate the DW production caused by a second-order phase transition and calculate the SGWB spectrum using a $1000\times 1000\times 1000$ lattice. We show that the SGWB can be observed directly by future terrestrial and spatial gravitational wave detectors and through the B-mode spectrum in CMB. This signal can also explain the common noise process observed by pulsar timing array experiments. With numerical simulations, we derive an empirical formula for the strength and qualitative features of the SGWB spectrum. The details of the SGWB spectrum also contain information about the later evolution of the universe.

   hep-phastro-ph.COPRD(2024)·39 citations
7. 07*

   Gravitational echoes of lepton number symmetry breaking with light and ultralight Majorons

   Andrea Addazi🇨🇳 · Antonino Marcianò🇮🇹 · António P. Morais🇨🇭 · Roman Pasechnik🇸🇪 · João Viana🇵🇹 · Hao Yang🇨🇳

   We formulate a version of the low-scale Majoron model equipped with an inverse seesaw mechanism featuring lepton-number preserving dimension-6 operators in the scalar potential. Contrary to its dimension-4 counterpart, we find that the model can simultaneously provide light and ultralight Majorons, neutrino masses and their mixing, while featuring strong first-order cosmological phase transitions associated to the spontaneous breaking of the lepton number and the electroweak symmetries in the early Universe. We show by a detailed numerical analysis that under certain conditions on the parameter space accounted for in collider physics, the model can be probed via the primordial gravitational wave spectrum potentially observable at LISA and other planned facilities.

   hep-phastro-ph.COJCAP(2023)·15 citations
8. 08*

   Stringent bounds on $HWW$ and $HZZ$ anomalous couplings with quantum tomography at the LHC

   M. Fabbrichesi🇮🇹 · R. Floreanini🇮🇹 · E. Gabrielli🇮🇹 · L. Marzola🇪🇪

   Quantum tomography provides the full reconstruction of the density matrix of a state. We use it to study the Higgs boson decay into weak gauge bosons. Anomalous couplings beyond the Standard Model can be constrained by means of observables easily defined in terms of the polarization density matrix. We describe a strategy based on three observables that together provide the most stringent limits. Two of these observables are linked to the entanglement between the polarizations of the two gauge bosons, the other is based on CP-odd combinations of one momentum and two polarizations. We find for the $Z$ channel that this strategy offers, already with the available LHC data, limits competitive with the best available bounds. We argue that the inclusion of these observables in routine experimental analyses can lead to more stringent global fit limits.

   hep-phhep-exJHEP(2023)·54 citations
9. 09*

   Quantum mismatch: a powerful measure of "quantumness" in neutrino oscillations

   Dibya S. Chattopadhyay🇮🇳 · Amol Dighe🇮🇳

   The quantum nature of neutrino oscillations would be reflected in the mismatch between the neutrino survival probabilities with and without an intermediate observation. We propose this ``quantum mismatch'' as a measure of quantumness in neutrino oscillations, which precisely extracts the interference term in the two-flavor limit. In the full three-flavor scenario, we provide modified definitions of the Leggett-Garg and quantum mismatch measures. These are applicable for long-baseline and reactor neutrino experiments that measure neutrino survival probabilities with negligible matter effects.

   hep-phhep-exquant-phPRD(2023)·14 citations
10. 10*

    PTOLEMY's test of generalized neutrino interactions: unveiling challenges and constraints

    Indra Kumar Banerjee🇮🇳 · Ujjal Kumar Dey🇮🇳 · Newton Nath🇮🇹 · Saadat Salman Shariff🇮🇳

    Unanswered questions surrounding neutrinos have motivated investigations into physics beyond the standard model (SM) of particle physics. In particular, generalized neutrino interactions (GNI) provide a broader framework for studying these effects compared to the commonly studied non-standard neutrino interactions. These interactions are described by higher dimensional operators while maintaining the gauge symmetries of the SM. Furthermore, the cosmic neutrino background, a predicted component of the SM and standard cosmology, has yet to be directly detected. To shed light on this elusive phenomenon, we conduct a comprehensive analysis of the relevant GNI, specifically focusing on their implications for the proposed cosmic neutrino detector PTOLEMY. We make an attempt to see the capabilities and the limitations of PTOLEMY in sensing GNI while remaining optimistic regarding PTOLEMY's experimental resolution. These interactions play a significant role in modifying the electron spectrum resulting from the capture of cosmic neutrinos on radioactive tritium. This work also explores how the presence of these interactions influences the differential electron spectrum, taking into account factors such as finite experimental resolution, the mass of the lightest neutrino eigenstate, the strength of the interactions, and the ordering of neutrino mass.

    hep-phastro-ph.HEhep-exJCAP(2024)·15 citations
11. 11*

    Gravitational waves from cosmic strings associated with pseudo-Nambu-Goldstone dark matter

    Ze-Yu Qiu🇨🇳 · Zhao-Huan Yu🇨🇳

    We study stochastic gravitational waves from cosmic strings generated in an ultraviolet-complete model for pseudo-Nambu-Goldstone dark matter with a hidden $\mathrm{U}(1)$ gauge symmetry. The dark matter candidate in this model can naturally evade direct detection bounds and easily satisfy other phenomenological constraints. The bound on the dark matter lifetime implies an ultraviolet scale higher than $10^9\mathrm{GeV}$. The spontaneous $\mathrm{U}(1)$ symmetry breaking at such a high scale would induce cosmic strings with high tension, resulting in a stochastic gravitational wave background with a high energy density. We investigate the constraints from current gravitational wave experiments as well as the future sensitivity. We find that most viable parameter points can be well studied in future gravitational wave experiments.

    hep-phastro-ph.COCPC(2023)·18 citations
12. 12*

    Towards the optimal beam dump experiment to search for feebly interacting particles

    Kyrylo Bondarenko🇮🇹 · Alexey Boyarsky🇳🇱 · Oleksii Mikulenko🇳🇱 · Richard Jacobsson🇨🇭 · Maksym Ovchynnikov🇩🇪

    Future searches for new physics beyond the Standard Model are without doubt in need of a diverse approach and experiments with complementary sensitivities to different types of classes of models. One of the directions that should be explored is feebly interacting particles (FIPs) with masses below the electroweak scale. The interest in FIPs has significantly increased in the last ten years. Searches for FIPs at colliders have intrinsic limitations in the region they may probe, significantly restricting exploration of the mass range $m_{\text{FIP}}<5-10$\,GeV/c${}^2$. Beam dump-like experiments, characterized by the possibility of extremely high luminosity at relatively high energies and the effective coverage of the production and decay acceptance, are the perfect option to generically explore the ``coupling frontier'' of the light FIPs. Several proposals for beam-dump detectors are currently being considered by CERN for implementation at the SPS ECN3 beam facility. In this we paper we analyse in depth how the characteristic geometric parameters of a beam dump experiment influence the signal yield. We apply an inclusive approach by considering the phenomenology of different types of FIPs. From the various production modes and kinematics, we demonstrate that the optimal layout that maximises the production and decay acceptance consists of a detector located on the beam-axis, at the shortest possible distance from the target defined by the systems required to suppress the beam-induced backgrounds.

    hep-phhep-exEPJC(2023)·12 citations
13. 13*

    A Quantum Perspective on Oscillation Frequencies in Axion Dark Matter Experiments

    Joerg Jaeckel🇩🇪 · Valentina Montoya🇩🇪 · Cedric de Jonge

    In this note we look at the time evolution of signals in axion dark matter experiments from a quantum perspective. Our aim is not to contribute new results to the general discussion of the quantum/classical connection (which we do not) but rather to slightly illuminate the specific case of axion experiments. From the classical perspective one expects a signal oscillating with a frequency equal to the axion mass whose amplitude is slowly rising due to the tiny interaction of the axions with ordinary matter. In the quantum picture the latter, slow time-scale arises from the small splitting in the energy levels induced by the interaction between the axions and the experiment, and it is always present in suitable, sensitive experiments. Signals that oscillate with a frequency equal to the axion mass, however, arise from processes changing the axion number. Yet, depending on the chosen observable, such oscillations may be absent for certain special initial quantum states of the axions. However, we show by example that, using an appropriate experimental procedure, these special states can be modified by the experiment in such a way that a signal oscillating with the axion mass re-appears. In addition, we discuss the measurement of suitable correlators that feature an oscillation with the axion mass. We also comment on the connection to the classical treatment. The explicit experiment we look at is an oscillating EDM experiment such as CASPEr but we expect our results to be easily adaptable to other types of axion dark matter experiments.

    hep-phhep-exAnnalen Phys.(2024)·0 citations
14. 14*

    $\Delta S=2$ nonleptonic hyperon decays as probes of new physics

    Xiao-Gang He🇨🇳 · Jusak Tandean🇮🇩 · German Valencia🇦🇺

    Hyperon nonleptonic decays that change strangeness by two units, such as $\Xi \to N\pi$ and ${\Omega }^{-}\to n{K}^{-},\Lambda {\pi }^{-},{\Sigma }^{(\ast )}\pi$, are highly suppressed in the standard model. Only a few of them have been searched for to date, leading to experimental upper bounds which are many orders of magnitude above the expectations of the standard model. This leaves ample opportunity to look for indications of new physics in these processes. At the same time, most, but not all, $\Delta S=2$ interactions beyond the standard model are severely constrained by kaon-mixing data. We present two scenarios where new physics satisfying the kaon-mixing constraints can enhance the hyperon decay rates to levels that can be probed in future quests by BESIII and LHCb and at the proposed Super Tau-Charm Factory. Both scenarios require significant fine-tuning.

    hep-phhep-exPRD(2023)·6 citations
15. 15*

    Naturalness in Soft Leptogenesis and Gravitino Mass Bound due to Primordial Black Holes

    Suhail Khan🇮🇳 · Rathin Adhikari🇮🇳

    If sneutrinos are produced through primordial black hole (PBH) evaporation, then some interesting features of soft leptogenesis in the Minimal Supersymmetric Standard Model with heavy right-handed neutrinos, are found. The required baryonic asymmetry could be possible from the decays of sneutrinos, for the soft SUSY breaking trilinear $A$ and bilinear $B$ parameters around the electroweak scale. The resonance condition in soft leptogenesis is not required. The allowed regions of different relevant parameters are discussed in detail. Using experimental constraints from collider searches on heavy leptons, the lower bound on the right-handed neutrino mass is found to be around $300$ GeV with Yukawa coupling lesser than about $0.4$. The allowed region of the typical mass scale of some supersymmetric particles and the $|A|$ parameter is also shown from the experimental constraint on the branching ratio for $\mu \to e\gamma$ in MEG-II search. Depending on PBH mass, bounds on the mass of gravitinos, produced from PBH evaporation, is discussed and gravitino mass around the electroweak scale is found to be possible only for unstable gravitino.

    hep-phastro-ph.HEhep-thPhys.Dark Univ.(2025)·2 citations
16. 16*

    Exact spin polarization of massive and massless particles in relativistic fluids at global equilibrium

    Andrea Palermo🇮🇹 · Francesco Becattini🇮🇹

    We present the exact form of the spin polarization vector and the spin density matrix of massive and massless free particles of any spin and helicity at general global equilibrium in a relativistic fluid with non-vanishing thermal vorticity, thus extending the known expression at the linear order. The exact form is obtained by means of the analytic continuation of the relativistic density operator to imaginary thermal vorticity and the resummation of the obtained series. The phenomenological implications for the polarization of the $\Lambda$ hyperon in relativistic heavy-ion collisions are addressed.

    ↳ nucl-thhep-phhep-thEur.Phys.J.Plus(2023)·24 citations
17. 17*

    Analytic false-vacuum decay rate in the thin-wall approximation

    Marco Matteini🇸🇮 · Miha Nemevšek🇸🇮 · Lorenzo Ubaldi🇸🇮

    We present a fully analytical calculation of the false vacuum decay rate for a self-interacting scalar field in the thin-wall approximation. We obtain the bounce solution, together with the Euclidean action, counter-terms and renormalization group running, and we extract the functional determinant via the Gel'fand-Yaglom theorem. Our procedure is valid for a generic spacetime dimension $D$, and we provide an explicit finite renormalized decay rate in $D=3,4$.

    ↳ hep-thhep-phPoS(2023)·2 citations
18. 18*

    A+2n compound nuclei and the unitary limit in nuclear physics

    P. E. Georgoudis🇫🇷

    This contribution discusses a new perception of the structure of compound nuclei by introducing intermediate states of the Feshbach formalism of nuclear reactions in the Interacting Boson Model of nuclear structure. The stake is to explore the manifestation of the unitary limit in heavy, even-even nuclei. Interactions that govern Feshbach resonances of cold and dilute atomic gases suggest the formulation of an IBM-compound Hamiltonian for scattering two neutrons (2n) from a heavy, even-even target (A). The solutions of the corresponding coupled channel equations host a 2n-IBM state resonance. It turns out that the unitary limit is measurable in a heavy A+2n compound nucleus at low temperatures. That measurement is feasible through the fluctuations of the cross-sections that tune the 2n-A scattering length.

    ↳ nucl-thcond-mat.quant-gashep-phnucl-exJ.Phys.Conf.Ser.(2023)·1 citation
19. 19*

    Temperature and Strong Magnetic Field Effects in Dense Matter

    J. Peterson🇺🇸 · P. Costa🇵🇹 · R. Kumar🇺🇸 · V. Dexheimer🇺🇸 · R. Negreiros🇧🇷 · C. Providencia🇵🇹

    We study consistently the effects of magnetic field on hot and dense matter. In particular, we look for differences that arise due to assumptions that reproduce the conditions produced in particle collisions or astrophysical scenarios, such as in the core of fully evolved neutron stars (beyond the protoneutron star stage). We assume the magnetic field to be either constant or follow a profile extracted from general relativity calculations of magnetars and make use of two realistic models that can consistently describe chiral symmetry restoration and deconfinement to quark matter, the Chiral Mean Field (CMF) and the Polyakov-loop extended Nambu-Jona-Lasinio (PNJL) models. We find that net isospin, net strangeness, and weak chemical equilibrium with leptons can considerably change the effects of temperature and magnetic fields on particle content and deconfinement in dense matter. We finish by discussing the possibility of experimentally detecting quark deconfinement in dense and/or hot matter and the possible role played by magnetic fields.

    ↳ nucl-thastro-ph.HEastro-ph.SRhep-phPRD(2023)·21 citations
20. 20*

    Quantitative constraints on modified gravity paradigms

    S. R. Pinto🇵🇹 · A. M. Cabral🇵🇹 · C. J. A. P. Martins🇵🇹

    We use low-redshift background cosmology data to place quantitative constraints on three separate modified gravity models, each of which aims to explain the low-redshift acceleration through a different physical mechanism. The Lifshitz cosmology is effectively a parametric extension of the canonical $\Lambda$CDM model, where a time-dependent cosmological constant originates from vacuum energy. The Infinite Statistics model is also a parametric extension of $\Lambda$CDM, where the dark energy is dynamic and originates from the curvature of a dual space-time. We show that the data restricts the additional parameters in these models to be consistent with their $\Lambda$CDM values, and in particular that it implies that the theoretically predicted value for a dimensionless coupling parameter in the Lifshitz model is ruled out at more than six standard deviations. In the Regge-Teitelboim model, gravity is described by embedding the usual space-time manifold in a fixed higher-dimensional background, and there is no parametric $\Lambda$CDM limit. We study several separate realizations of the model, respectively introduced by Davidson, by Fabi \textit{et al.}, and by Stern \& Xu, and show that the first two are ruled out by the low-redshift data we use, while the latter is consistent with this data but requires a non-standard value of the matter density. Overall, our analysis highlights the tight constraints imposed by current data on the allowed low-redshift deviations from the standard $\Lambda$CDM background evolution.

    ↳ astro-ph.COgr-qchep-phPRD(2023)·3 citations
21. 21*

    Massive Gravity is not Positive

    Brando Bellazzini🇫🇷 · Giulia Isabella🇫🇷 · Sara Ricossa🇨🇭 · Francesco Riva🇨🇭

    We derive new positivity bounds at finite momentum transfer, assuming a large separation between the mass $m$ of the lightest particle in the effective theory and the mass gap $M$ to new heavy states. Massive gravity parametrically violates these bounds unless the cutoff is within one order of magnitude of the graviton mass $M\lesssim O(10)m$. Non-gravitational effective theories of massive spin-2 particles are similarly bounded.

    ↳ hep-thgr-qchep-phPRD(2024)·67 citations
22. 22*

    Symbol Alphabets from the Landau Singular Locus

    Christoph Dlapa🇩🇪 · Martin Helmer🇺🇸 · Georgios Papathanasiou🇩🇪 · Felix Tellander🇩🇪

    We provide evidence through two loops, that rational letters of polylogarithmic Feynman integrals are captured by the Landau equations, when the latter are recast as a polynomial of the kinematic variables of the integral, known as the principal $A$-determinant. Focusing on one loop, we further show that all square-root letters may also be obtained, by re-factorizing the principal $A$-determinant with the help of Jacobi identities. We verify our findings by explicitly constructing canonical differential equations for the one-loop integrals in both odd and even dimensions of loop momenta, also finding agreement with earlier results in the literature for the latter case. We provide a computer implementation of our results for the principal $A$-determinants, symbol alphabets and canonical differential equations in an accompanying Mathematica file. Finally, we study the question of when a one-loop integral satisfies the Cohen-Macaulay property and show that for almost all choices of kinematics the Cohen-Macaulay property holds. Throughout, in our approach to Feynman integrals, we make extensive use of the Gel'fand, Graev, Kapranov and Zelevinski\uı theory on what are now commonly called GKZ-hypergeometric systems whose singularities are described by the principal $A$-determinant.

    ↳ hep-thhep-phJHEP(2023)·47 citations
23. 23*

    Imprints of a Supercooled Phase Transition in the Gravitational Wave Spectrum from a Cosmic String network

    Francesc Ferrer🇺🇸 · Anish Ghoshal🇵🇱 · Marek Lewicki🇵🇱

    A network of cosmic strings (CS), if present, would continue emitting gravitational waves (GW) as it evolves throughout the history of the Universe. This results in a characteristic broad spectrum making it a perfect source to infer the expansion history. In particular, a short inflationary period caused by a supercooled phase transition would cause a drop in the spectrum at frequencies corresponding to that event. However, the impact on the spectrum is similar to the ones caused by an early matter-dominated era or from particle production, making it difficult to disentangle these different physical origins. We point out that, in the case of a short inflationary period, the GW spectrum receives an additional contribution from the phase transition itself. This leads to a characteristic imprint of a peak on top of a wide plateau both visible at future GW observatories.

    ↳ astro-ph.COhep-phJHEP(2023)·19 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.