Wed·Nov 3, 2021Wednesday·November 3, 2021

1. 01*

   Positivity and renormalization of parton densities

   John Collins🇺🇸 · Ted C. Rogers🇺🇸 · Nobuo Sato🇺🇸

   There have been recent debates about whether $\overline{\text{MS}}$ parton densities exactly obey positivity bounds (including the Soffer bound), and whether the bounds should be applied as a constraint on global fits to parton densities and on nonperturbative calculations. A recent paper (JHEP $\text{11}$ (2020) 129) appears to provide a proof of positivity in contradiction with earlier work by other authors. We examine their derivation and find that its primary failure is in the apparently uncontroversial statement that bare pdfs are always positive. We show that under the conditions used in the derivation, that statement fails. We provide some elementary calculations in a model QFT that show how this situation can generically arise in reality. In addition, we observe that the methods used in the derivation are in common with much, but not all, other work where factorization is derived. Our examination pinpoints considerable difficulties with these methods that render them either wrong or highly problematic. The issue of positivity highlights that these methods can lead to wrong results of phenomenological importance. From our analysis we identify the restricted situations in which positivity can be violated.

   hep-phhep-exnucl-thPRD(2022)·59 citations
2. 02*

   Constraining New Physics with Possible Dark Matter Signatures from a Global CKM Fit

   Aritra Biswas🇮🇳 · Lopamudra Mukherjee🇮🇳 · Soumitra Nandi🇮🇳 · Sunando Kumar Patra🇮🇳

   We constrain the parameters of a representative new physics model with possible dark matter (DM) signature from a global CKM fit analysis. The model has neutral quark current interactions mediated by a scalar, impacting the semileptonic and purely leptonic meson decays at one-loop. We take this opportunity to update the fit results for the Wolfenstein parameters and the CKM elements with and without a contribution from the new model using several other updated inputs. Alongside, we have analyzed and included in the CKM fit the $B\to D^{\ast }\ell {\nu }_{\ell }$ decay. The newly available inputs on the relevant form factors from lattice are included, and the possibility of new physics effects in $B\to D^{\ast }\ell {\nu }_{\ell }$ is considered. We obtain tight constraints on the relevant new physics parameters. We have studied the possible implications of this constraint on DM phenomenology. Apart from DM, the bounds are also applicable in other relevant phenomenological studies.

   hep-phhep-exhep-latPRD(2023)·13 citations
3. 03*

   Muon $g-2$ and Screened Modified Gravity

   Philippe Brax🇫🇷 · Anne-Christine Davis🇬🇧 · Benjamin Elder🇺🇸

   We show how light scalar fields can account for the discrepancy between the theoretical and observed values of the anomalous magnetic moment of the (anti)muon. When coupled to both matter and photons, light scalar fields induce a change of the anomalous magnetic moment of charged particles. This arises from two concurrent effects. Classically, light scalars induce a change of the cyclotron frequency, complementing the electromagnetic effects coming from the magnetic and electric fields used experimentally. Light scalars also contribute to the anomalous magnetic moment quantum mechanically at the one-loop level. For unscreened scalar fields coupling with a Yukawa interaction to matter, these contributions are negligible after applying the Cassini bound on deviations from Newtonian gravity. On the other hand, screened scalars such as chameleons or symmetrons can couple strongly to matter in the laboratory and decouple in the Solar System. This allows us to probe branches of their parameter spaces where the recently measured anomalous magnetic moment of the (anti)muon can be accounted for in the chameleon and symmetron cases. This might be a hint that modified gravity is at play in the laboratory.

   hep-phastro-ph.COgr-qcPRD(2022)·19 citations
4. 04*

   Revisiting Dark Matter Freeze-in and Freeze-out through Phase-Space Distribution

   Yong Du🇨🇳 · Fei Huang🇨🇳 · Hao-Lin Li🇨🇳 · Yuan-Zhen Li🇨🇳 · Jiang-Hao Yu🇨🇳

   We revisit dark-matter production through freeze-in and freeze-out by solving the Boltzmann equations at the level of the phase-space distribution $f(p,t)$. Using the $2\to 2$ annihilation and the $1\to 2$ decay processes for illustration, we compare the resulting dark-matter relic abundance with that from the number-density approach. In the transition regime between freeze-in and freeze-out, we find the difference can be quite significant, or even by orders of magnitude if the annihilation of dark-matter particles or the decaying mediator is neglected. The freeze-in production in the $2\to 2$ and the $1\to 2$ processes can also result in non-thermal phase-space distributions, or even multi-modal ones with out-of-equilibrium decay, which can potentially affect structure formation at late times. We also investigate how elastic scatterings can distort such non-thermal distributions.

   hep-phastro-ph.COJCAP(2022)·57 citations
5. 05*

   IR-Improved Amplitude-Based Resummation in Quantum Field Theory: New Results and New Issues

   B.F.L. Ward (1)🇺🇸 · S. Jadach (2)🇵🇱 · W. Placzek (3)🇵🇱 · M. Skrzypek (2)🇵🇱 · Z. Was (2)🇵🇱 · S.A. Yost (4) ((1) Baylor University, Waco, TX, USA, (2) Institute of Nuclear Physics, Krakow, Poland, (3) Institute of Applied Computer Science, Jagiellonian University, Krakow, Poland, (4) The Citadel, Charleston, SC, USA)🇺🇸

   With the advancement of strategies for the precision physics programs for the HL-LHC, FCC-ee, FCC-hh, ILC, CLIC, CEPC, and CPPC, the need for proper control of the attendant theoretical precision tags is manifest. We discuss the role that amplitude-based resummation may play in this regard with examples from the LHC, the proposed new colliders and quantum gravity.

   hep-phSciPost Phys.Proc.(2022)·2 citations
6. 06*

   Electroweak baryogenesis by axionlike dark matter

   Sang Hui Im🇰🇷 · Kwang Sik Jeong🇰🇷 · Yeseong Lee🇰🇷

   We show that an axionlike particle (ALP) naturally implements spontaneous electroweak baryogenesis through a cosmic evolution strongly tied to the electroweak phase transition (EWPT) if it feebly couples to the Higgs field while giving a small contribution to the Higgs boson mass. The observed baryon asymmetry can be generated successfully if the ALP couples strongly enough to the electroweak anomaly. Also interesting is that the ALP contributes to dark matter, and its coupling to a hidden gauge sector makes the relic abundance insensitive to the cosmic history before the EWPT. The ALP explains both the baryon asymmetry and dark matter in a wide range of the couplings owing to the friction induced by the hidden gauge sector. To be compatible with cosmological and astrophysical observations, the ALP should have a mass in the range between about 0.01 and 30 eV, and is further required to be photophobic if its coupling to the electroweak anomaly is strong, constraining the field content and charge assignment of the UV completion.

   hep-phPRD(2022)·20 citations
7. 07*

   Photoproduction reaction $\gamma n\to K^{\ast 0}\Lambda$ in an effective Lagrangian approach

   Neng-Chang Wei🇨🇳 · Yi-Ming Zhu🇨🇳 · Fei Huang🇨🇳

   In our previous work [Phys. Rev. C 101, 014003 (2020)], the photoproduction reaction $\gamma p\to K^{\ast +}\Lambda$ has been investigated within an effective Lagrangian approach. There, the reaction amplitudes were constructed by including the $t$-channel $K$, $K^{\ast }$, and $\kappa$ exchanges, the $u$-channel $\Lambda$, $\Sigma$, and ${\Sigma }^{\ast }$ exchanges, the $s$-channel $N$, $N(2000)5/2^{+}$, and $N(2060)5/2^{-}$ exchanges, and the interaction current. It has been shown that the data on both the differential cross sections and the spin density matrix elements were simultaneously and satisfactorily described. In this paper, we study the photoproduction reaction $\gamma n\to K^{\ast 0}\Lambda$ based on the same reaction mechanism as that of $\gamma p\to K^{\ast +}\Lambda$ with the purpose of getting a unified description of the data for both $\gamma p\to K^{\ast +}\Lambda$ and $\gamma n\to K^{\ast 0}\Lambda$ within a same model. All hadronic coupling constants, form factor cutoffs, and the resonance masses and widths in the present calculations remain the same as in our previous work for $\gamma p\to K^{\ast +}\Lambda$. The available differential cross-section data for $\gamma n\to K^{\ast 0}\Lambda$ are well reproduced. Further analysis shows that the cross sections of $\gamma n\to K^{\ast 0}\Lambda$ are dominated by the contributions of the $t$-channel $K$ exchange, while the $s$-channel $N(2000)5/2^{+}$ and $N(2060)5/2^{-}$ exchanges provide considerable contributions as well.

   hep-phCPC(2022)·0 citations
8. 08*

   The $\eta$- and ${\eta }^{\prime }$-nucleus interactions and the search for $\eta$, ${\eta }^{\prime }$- mesic states

   Steven D. Bass🇵🇱 · Volker Metag🇩🇪 · Pawel Moskal🇵🇱

   The isoscalar $\eta$ and ${\eta }^{\prime }$ mesons are special in QCD, being linked both to chiral symmetry and to non-perturbative glue associated with the axial anomaly. The properties of these mesons in medium are sensitive to how these dynamics work in the nuclear environment. In contrast to pionic and kaonic atoms which are mainly bound by the Coulomb interaction with some corrections due to the strong force (Coulomb assisted binding), the $\eta$ and ${\eta }^{\prime }$ as neutral mesons can only be bound by the strong interaction. Is this interaction strong enough? This topic has inspired a vigorous program of experiments, conducted in close contact with theory, One has to determine the complex $\eta$, ${\eta }^{\prime }$-nucleus potential. Does the real part $V$ provide a sufficiently deep potential? Is the imaginary part $W$ small enough to allow for narrow states that can more easily be detected experimentally, i.e. $|W|\ll |V|$? The ${\eta }^{\prime }$ effective mass is observed to be suppressed by $\approx -40$ MeV at nuclear matter density. Bound state searches are ongoing. This article gives an overview of the status of knowledge in this field together with an outlook to future experiments.

   hep-phnucl-exnucl-thIn: Tanihata, I., Toki, H., Kajino, T. (e…·11 citations
9. 09*

   Revisiting quark-hadron duality for heavy meson non-leptonic decays in two-dimensional QCD

   Hiroyuki Umeeda🇹🇼

   We study lifetimes of heavy mesons in the 't Hooft model, a large-$N_c$ theory of strong interaction in two-dimensional spacetime. Since this model is solvable, one can evaluate the total decay widths through hadronic amplitudes that are determined unambiguously within the formalism. We investigate quark-hadron duality by numerically comparing the exclusive result and one from the heavy quark expansion, with the contribution of Pauli interference being consistently incorporated. Within certain numerical accuracy, we find that the maximal difference between inclusive and exclusive rates for $\tau [D_s^{+}]/\tau [D^0]$ $(\tau [B^{+}]/\tau [B^0])$ is as large as the current experimental (theoretical) error in four-dimensions, except for $\tau [D^{+}]/\tau [D^0]$, where an excellent agreement between the rates is seen.

   hep-phPLB(2022)·5 citations
10. 10*

    Production and decay of the Higgs boson in association with top quarks

    Daniel Stremmer🇩🇪 · Malgorzata Worek🇩🇪

    We report on the calculation of the next-lo-leading order QCD corrections to Higgs boson production and decay in association with top quarks. We consider leptonic decays of top quarks leading to the hadronic process $pp\to e^{+}{\nu }_e{\mu }^{-}{\bar{\nu }}_{\mu }b\bar{b}H(H\to X)$ at the LHC with $\sqrt{s}=13$ TeV. All resonant as well as non-resonant Feynman diagrams, interferences and off-shell effects are included for the top quark and $W$ gauge boson. Decays of the Higgs boson, on the other hand, are included in the narrow-width-approximation. Specifically, we consider Higgs boson decays into $b\bar{b}$, ${\tau }^{+}{\tau }^{-}$, $\gamma \gamma$ and $e^{+}{e}^{-}{e}^{+}{e}^{-}$. Numerical results are given at the integrated and differential fiducial level for various factorisation and renormalisation scale choices and different PDF sets. We study the main theoretical uncertainties that are associated with neglected higher order terms in the perturbative expansion and with different parametrisations of the PDFs. Furthermore, we examine the size of the off-shell effects by an explicit comparison to the calculation in the full narrow-width-approximation. Finally, the impact of the contributions induced by the bottom-quark parton density is investigated.

    hep-phhep-exJHEP(2022)·34 citations
11. 11*

    Prospects for discovering new physics in charm sector through low-energy scattering processes $e^{-}p\to e^{-}({\mu }^{-}){\Lambda }_c$

    Li-Fen Lai🇨🇳 · Xin-Qiang Li🇨🇳 · Xin-Shuai Yan🇨🇳 · Ya-Dong Yang🇨🇳

    We investigate the potential for discovering new physics through the low-energy scattering processes $e^{-}p\to e^{-}({\mu }^{-}){\Lambda }_c$, which could be accessible in the forthcoming $ep$ scattering experiments once adapted to our proposed setups. In the framework of a general low-energy effective Lagrangian, we demonstrate that, compared with the conventional flavor-changing neutral-current weak decays of charmed hadrons and the dilepton productions at high-energy colliders, the low-energy scattering processes can provide more competitive potentials for hunting the underlying new physics. In some specific leptoquark models, we also show that promising event rates can be expected for both the scattering processes, and point out a possible way to distinguish the experimental signals due to the scalar leptoquarks from those of the vector ones.

    hep-phhep-exPRD(2022)·5 citations
12. 12*

    The Soft Anomalous Dimension at four loops in the Regge Limit

    Niamh Maher🇬🇧 · Giulio Falcioni🇬🇧 · Einan Gardi🇬🇧 · Calum Milloy🇮🇹 · Leonardo Vernazza🇮🇹

    The soft anomalous dimension governs the infrared divergences of scattering amplitudes in general kinematics to all orders in perturbation theory. By comparing the recent Regge-limit results for $2\to 2$ scattering (through Next-to-Next-to-Leading Logarithms) in full colour to a general form for the soft anomalous dimension at four loops we derive powerful constraints on its kinematic dependence, opening the way for a bootstrap-based determination.

    hep-phhep-thSciPost Phys.Proc.(2022)·5 citations
13. 13*

    From Wigner distributions of photons to dilepton production in semicentral heavy ion collisions

    Mariola Kłusek-Gawenda🇵🇱 · Wolfgang Schäfer🇵🇱 · Antoni Szczurek🇵🇱 · Roxana Busuioc🇬🇧 · Yash Arya🇮🇳

    We present a formalism how to calculate differential distributions for dilepton production in semicentral heavy ion collisions. In this new approach, the differential cross section is calculated using the complete polarization density matrix of photons resulting from the Wigner distribution formalism. The formalism is used to calculate different distributions of the invariant mass, dilepton transverse momentum and acoplanarity for different regions of centrality. The results of the calculation are compared with recent experimental data. We also study the contribution from different parts of impact parameter space.

    hep-phPoS(2022)·0 citations
14. 14*

    Toward twist-2 $T$-odd transverse-momentum-dependent gluon distributions: the $f$-type Sivers function

    Alessandro Bacchetta🇮🇹 · Francesco Giovanni Celiberto🇮🇹 · Marco Radici🇮🇹

    We report progresses on leading-twist transverse-momentum-dependent (TMD) gluon distributions, calculated in a spectator-model framework for the parent nucleon. We encode in our formalism a fit-based parameterization for the spectator-mass density, suited to describe the gluon content of the proton in a wide range of $x$. We present preliminary results on the $f$-type Sivers function, a key ingredient to access relevant spin-asymmetries emerging when the nucleon is transversely polarized. These studies are helpful to shed light on the gluon dynamics inside nucleons and nuclei, which is one of the primary goals of new-generation colliding facilities, as the Electron-Ion Collider, the High-Luminosity LHC, NICA-SPD, and the Forward Physics Facility.

    hep-phPoS(2022)·46 citations
15. 15*

    Coulomb phase corrections to the transverse analyzing power $A_N(t)$ in high energy forward proton-proton scattering

    A. A. Poblaguev🇺🇸

    Study of polarized proton-proton elastic scattering in the Coulomb-nuclear interference region allows one to measure the forward hadronic single spin-flip amplitude including its phase. However, in a precision experimental data analysis, a phase shift correction ${\delta }_C$ due to the long distance Coulomb interaction should be taken into account. For unpolarized scattering, ${\delta }_C$ is commonly considered as well established. Here, we evaluate the Coulomb phase shifts for the forward elastic proton-proton single spin-flip electromagnetic and hadronic amplitudes. Only a small discrepancy between the spin-flip and non-flip phases was found which can be neglected in the high energy forward elastic $pp$ studies involving transverse spin. Nonetheless, the effective alteration of the hadronic spin-flip amplitude by the long distance electromagnetic corrections can be essential for interpretation of the experimental results.

    hep-phPRD(2022)·10 citations
16. 16*

    Hadronic structure on the light-front II: QCD strings, Wilson lines and potentials

    Edward Shuryak🇺🇸 · Ismail Zahed🇺🇸

    This is the second paper on hadronic wave functions in the light front formulation. We first consider only confinement effects, using the classical Nambu-Gotto string with massive end points in the light cone gauge. We derive the light-front Hamiltonian and show how to solve it, using an expansion in suitable basis functions. We next discuss the correlators of Wilson lines on the light front, leading to an effective Hamiltonian that includes spin effects. At the end, we consider a separate problem of instanton-induced interactions, at the origin of the pion as a massless Goldstone mode on the light front.

    hep-phhep-lathep-thnucl-thPRD(2023)·23 citations
17. 17*

    A Helioscope for Gravitationally Bound Millicharged Particles

    Asher Berlin🇺🇸 · Katelin Schutz🇨🇦

    Particles may be emitted efficiently from the solar interior if they are sufficiently light and weakly coupled to the solar plasma. In a narrow region of phase space, they are emitted with velocities smaller than the escape velocity of the solar system, thereby populating a gravitationally bound density that can accumulate over the solar lifetime, referred to as a "solar basin." Detection strategies that can succeed in spite of (or even be enhanced by) the low particle velocities are therefore poised to explore new regions of parameter space when taking this solar population into account. Here we identify "direct deflection" as a powerful method to detect such a population of millicharged particles. This approach involves distorting the local flow of gravitationally bound millicharges with an oscillating electromagnetic field and measuring these distortions with a resonant LC circuit. Since it is easier to distort the flow of slowly moving particles, the signal is parametrically enhanced by the small solar escape velocity near Earth. The proposed setup can probe couplings an order of magnitude smaller than other methods for millicharge masses ranging from 100 meV to 100 eV and can operate concurrently as a search for sub-GeV millicharged dark matter. The signal power scales as the millicharge coupling to the eighth power, meaning that even with conservative assumptions, direct deflection could begin to explore new regions of parameter space. We also highlight novel features of millicharge solar basins, including those associated with the phase space distribution and the possibility for the occupation number to vastly exceed that of a thermal distribution.

    hep-phastro-ph.SRhep-exPRD(2022)·30 citations
18. 18*

    Fuzzy Dark Matter and the Dark Energy Survey Year 1 Data

    Mona Dentler🇩🇪 · David J. E. Marsh🇬🇧 · Renée Hložek🇨🇦 · Alex Laguë🇨🇦 · Keir K. Rogers🇨🇦 · Daniel Grin🇺🇸

    Gravitational weak lensing by dark matter halos leads to a measurable imprint in the shear correlation function of galaxies. Fuzzy dark matter (FDM), composed of ultralight axion-like particles of mass $m\sim 10^{-22}\text{ eV}$, suppresses the matter power spectrum and shear correlation with respect to standard cold dark matter. We model the effect of FDM on cosmic shear using the optimised halo model \textsc{HMCode}, accounting for additional suppression of the mass function and halo concentration in FDM as observed in $N$-body simulations. We combine Dark Energy Survey year 1 (DES-Y1) data with the \emph{Planck} cosmic microwave background anisotropies to search for shear correlation suppression caused by FDM. We find no evidence of suppression compared to the preferred cold DM model, and thus set a new lower limit to the FDM particle mass. Using a log-flat prior and marginalising over uncertainties related to the non-linear model of FDM, we find a new, independent 95\% C.L. lower limit ${\log }_{10}m>-23$ combining \emph{Planck} and DES-Y1 shear, an improvement of almost two orders of magnitude on the mass bound relative to CMB-only constraints. Our analysis is largely independent of baryonic modelling, and of previous limits to FDM covering this mass range. Our analysis highlights the most important aspects of the FDM non-linear model for future investigation. The limit to FDM from weak lensing could be improved by up to three orders of magnitude with $\mathcal{O}(0.1)$ arcmin cosmic shear angular resolution, if FDM and baryonic feedback can be simultaneously modelled to high precision in the halo model.

    ↳ astro-ph.COhep-phMNRAS(2022)·99 citations
19. 19*

    The impact of ATLAS $V$+jet measurements on PDF fits

    Eimear Conroy (on behalf of the ATLAS collaboration)🇬🇧

    The production of $W$/$Z$-bosons in association with jets is an important test of perturbative QCD predictions and also yields information about the parton distribution functions of the proton. We present fits to determine PDFs using inclusive $W$/$Z$-boson and $W$/$Z$+jets measurements from the ATLAS experiment at the LHC. The ATLAS measurements are used in combination with deep-inelastic scattering data from HERA. An improved determination of the sea-quark densities at high Bjorken-$x$ is seen, while confirming a strange-quark density similar in size to the up- and down-sea-quark densities in the range $x<0.02$ found by previous ATLAS analyses.

    ↳ hep-exhep-phSciPost Phys.Proc.(2022)·0 citations
20. 20*

    Axi-Higgs cosmology: Cosmic Microwave Background and cosmological tensions

    Hoang Nhan Luu🇨🇳

    Non-canonical cosmology with an uplifted Higgs vacuum expectation value (Higgs-VEV) in the early universe is believed to provide the solution for existing tensions within the $\Lambda$CDM regime. We recently proposed a theoretical model called axi-Higgs to explore this framework. The axi-Higgs model features an ultralight axion with mass $m_a\sim 10^{-29}$ eV, which couples to the Higgs field such that the Higgs-VEV is driven by the axion background evolution. Phenomenologically, the axi-Higgs model is equivalent to $\Lambda$CDM+$m_e$+${\omega }_a$ which is defined as $\Lambda$CDM with electron mass variation and the presence of an ultralight axion. In this paper, we perform Markov Chain Monte Carlo analyses to investigate the parameter space of axi-Higgs and compare it with $\Lambda$CDM, $\Lambda$CDM+$m_e$ where only electron mass variation is allowed, and $\Lambda$CDM+${\omega }_a$ where only an ultralight axion is present. Combining observational data from Cosmic Microwave Background, Baryon Acoustic Oscillations, weak-lensing cosmic shear survey we found $H_0=69.4\pm 1.3$ km/s/Mpc, which reduces the Hubble tension to approximately $2.4\sigma$. Including data from supernovae Type IA and local Hubble measurement from SH0ES we found $H_0=71.34\pm 0.96$ km/s/Mpc. The presence of this Higgs-VEV-driving axion may be tested by atomic clock and quasar spectral measurements in the near future.

    ↳ astro-ph.COhep-phPRD(2023)·13 citations
21. 21*

    Primordial black holes and scalar induced gravitational waves from Higgs inflation with non-canonical kinetic term

    Jiong Lin🇨🇳 · Shengqing Gao🇨🇳 · Yungui Gong🇨🇳 · Yizhou Lu🇨🇳 · Zhongkai Wang🇨🇳 · Fengge Zhang🇨🇳

    We resolve the potential-restriction problem in K/G inflation by introducing nonminimal coupling. In this context, Higgs field successfully drives inflation satisfying CMB observations while enhancing curvature perturbations at small scales, which in turn accounts for primordial black holes (PBHs) and scalar induced gravitational waves (SIGWs). We then uncover the effect of the non-canonical kinetic coupling function in more detail and study its the observational constraint. Besides, we also give the gauge invariant expression for the integral kernel of SIGWs, which is related to terms propagating with the speed of light. Finally, the non-Gaussian effect on PBH abundance and SIGWs is studied. We find that non-Gaussianity makes PBHs form more easily, but its effect on the energy density of SIGWs is negligible.

    ↳ gr-qcastro-ph.COhep-phPRD(2023)·75 citations
22. 22*

    Role of inhomogeneities in the flattening of the quantum effective potential

    Gergely Endrődi🇩🇪 · Tamás G. Kovács🇭🇺 · Gergely Markó🇩🇪

    We investigate the role of inhomogeneous field configurations in systems with a spontaneously broken continuous global symmetry. Spontaneous breaking is usually defined as a specific double limit, first infinite volume at finite explicit breaking sources, which are then extrapolated to zero. We consider a different approach in which the order parameter is constrained under the path integral, which we simulate using lattice Monte Carlo techniques. In this way we access the flat region of the effective potential and we show that inhomogeneous configurations are dominant there. We topologically classify the important configurations and measure the excess energy stored in the inhomogeneities allowing for the definition of a generalized differential surface tension. We show that this contribution becomes negligible at large volumes restoring the flatness of the effective potential in the thermodynamic limit.

    ↳ hep-latcond-mat.stat-mechhep-phPoS(2022)·0 citations
23. 23*

    Modification of $Z^0$ leptonic invariant mass in ultrarelativistic heavy ion collisions as a measure of the electromagnetic field

    Yifeng Sun🇮🇹 · Vincenzo Greco🇮🇹 · Xin-Nian Wang🇺🇸

    An extraordinary strong magnetic field, $e{B}_0\approx 10^{18}$ Gauss, is expected to be generated in non-central ultrarelativistic heavy ion collisions and it is envisaged to induce several effects on hot QCD matter including the possibility of local parity and local parity and charge conjugation symmetry violations. A direct signature of such e.m. fields and a first quantitative measurement of its strength and lifetime are still missing. We point out that both the mean value of leptonic invariant mass of $Z^0$ boson, reconstructed by its decaying lepton pairs, and the relative width are modified in relativistic heavy ion collisions due to the presence of strong initial e.m. fields. We propose a measurement of the leptonic invariant mass of $Z^0$ as a novel probe of the strength of the $B_y$. Both shifts could be up to about few hundred MeV and are found to depend on the integral of $B_y$ over the time duration quadratically (approximate). Hence it provides a novel and clear probe of electromagnetic fields, which can be tested experimentally.

    ↳ nucl-thhep-phnucl-exPLB(2022)·9 citations
24. 24*

    Superdense beaming of axion dark matter in the vicinity of the light cylinder of pulsars

    Javier De Miguel🇯🇵 · Chiko Otani🇯🇵

    In this article we treat the non-adiabatic photon-to-axion resonant conversion of curvature radiation, synchrotron emission and inverse Compton scattering dominating the spectral density function of pulsars. First, we introduce emission models and benchmark observational data.vWe adopt a state-of-the-art density profile that relieves tension with the quantum electrodynamics vacuum polarization effect in highly magnetic stars, leading to efficient mixing. Then, we estimate the dark matter flux induced by photon-axion oscillation across the light cylinder of the neutron star. We find that pulsars might produce axion overdensities many orders of magnitude over the occupation number of dark matter in the Galactic halo within a broad parameter space. We point out possible new methods for axion detection derived from these results and other future lines of work.

    ↳ astro-ph.HEastro-ph.COastro-ph.SRhep-ph+1JCAP(2022)·4 citations
25. 25*

    Quantum signatures in nonlinear gravitational waves

    Thiago Guerreiro🇧🇷 · Francesco Coradeschi🇮🇹 · Antonia Micol Frassino🇪🇸 · Jennifer Rittenhouse West🇺🇸 · Enrico Junior Schioppa🇮🇹

    The effective quantum field theory description of gravity, despite its non-renormalizability, allows for predictions beyond classical general relativity. As we enter the age of gravitational wave astronomy, an important and timely question is whether measurable quantum predictions that depart from classical gravity, analogous to quantum optics effects which cannot be explained by classical electrodynamics, can be found. In this work, we investigate quantum signatures in gravitational waves using tools from quantum optics. Squeezed-coherent gravitational waves, which can exhibit sub-Poissonian graviton statistics, can enhance or suppress the signal measured by an interferometer, a characteristic effect of quantum squeezing. Moreover, we show that Gaussian gravitational wave quantum states can be reconstructed from measurements over an ensemble of optical fields interacting with a single copy of the gravitational wave, thus opening the possibility of detecting quantum features of gravity beyond classical general relativity.

    ↳ gr-qchep-phquant-phQuantum(2022)·31 citations
26. 26*

    The transversity parton distribution function of the nucleon using the pseudo-distribution approach

    Colin Egerer🇺🇸 · Christos Kallidonis🇺🇸 · Joseph Karpie🇺🇸 · Nikhil Karthik🇺🇸 · Christopher J. Monahan🇺🇸 · Wayne Morris🇺🇸 · Kostas Orginos🇺🇸 · Anatoly Radyushkin🇺🇸 · Eloy Romero🇺🇸 · Raza Sabbir Sufian🇺🇸 · Savvas Zafeiropoulos🇫🇷

    We present a determination of the non-singlet transversity parton distribution function (PDF) of the nucleon, normalized with respect to the tensor charge at ${\mu }^2=2$ GeV${}^2$ from lattice quantum chromodynamics. We apply the pseudo-distribution approach, using a gauge ensemble with a lattice spacing of 0.094 fm and the light quark mass tuned to a pion mass of 358 MeV. We extract the transversity PDF from the analysis of the short-distance behavior of the Ioffe-time pseudo-distribution using the leading-twist next-to-leading order (NLO) matching coefficients calculated for transversity. We reconstruct the $x$-dependence of the transversity PDF through an expansion in a basis of Jacobi polynomials in order to reduce the PDF ansatz dependence. Within the limitations imposed by a heavier-than-physical pion mass and a fixed lattice spacing, we present a comparison of our estimate for the valence transversity PDF with the recent global fit results based on single transverse spin asymmetry. We find the intrinsic nucleon sea to be isospin symmetric with respect to transversity.

    ↳ hep-lathep-exhep-phnucl-thPRD(2022)·54 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.