Thu·Jan 28, 2021Thursday·January 28, 2021

1. 01*

   Is a Miracle-less WIMP Ruled Out?

   Jason Arakawa🇺🇸 · Tim M. P. Tait🇺🇸

   We examine a real electroweak triplet scalar field as dark matter, abandoning the requirement that its relic abundance is determined through freeze out in a standard cosmological history (a situation which we refer to as a 'miracle-less WIMP'). We extract the bounds on such a particle from collider searches, searches for direct scattering with terrestrial targets, and searches for the indirect products of annihilation. Each type of search provides complementary information, and each is most effective in a different region of parameter space. LHC searches tend to be highly dependent on the mass of the SU(2) charged partner state, and are effective for very large or very tiny mass splitting between it and the neutral dark matter component. Direct searches are very effective at bounding the Higgs portal coupling, but ineffective once it falls below ${\lambda }_{\text{eff}}\lesssim 10^{-3}$. Indirect searches suffer from large astrophysical uncertainties due to the backgrounds and $J$-factors, but do provide key information for $\sim$ 100 GeV to TeV masses. Synthesizing the allowed parameter space, this example of WIMP dark matter remains viable, but only in miracle-less regimes.

   hep-phhep-exSciPost Phys.(2021)·20 citations
2. 02*

   Probing axion-like particles with $\gamma \gamma$ final states from vector boson fusion processes at the LHC

   Andrés Flórez🇨🇴 · Alfredo Gurrola🇺🇸 · Will Johns🇺🇸 · Paul Sheldon🇺🇸 · Elijah Sheridan🇺🇸 · Kuver Sinha🇺🇸 · Brandon Soubasis🇺🇸

   We perform a feasibility study to search for axion-like particles (ALPs) using vector boson fusion (VBF) processes at the LHC. We work in an effective field theory framework with cutoff scale $\Lambda$ and ALP mass $m_a$, and assume that ALPs couple to photons with strength $\propto 1/\Lambda$. Assuming proton-proton collisions at $\sqrt{s}=13$ TeV, we present the total VBF ALP production cross sections, ALP decay widths and lifetimes, and relevant kinematic distributions as a function of $m_a$ and $\Lambda$. We consider the $a\to \gamma \gamma$ decay mode to show that the requirement of an energetic diphoton pair combined with two forward jets with large dijet mass and pseudorapidity separation can significantly reduce the Standard Model backgrounds, leading to a $5\sigma$ discovery reach for $10\text{ MeV}\lesssim m_a\lesssim 1$ TeV with $\Lambda \lesssim 2$ TeV, assuming an integrated luminosity of 3000 fb${}^{-1}$. In particular, this extends the LHC sensitivity to a previously unstudied region of the ALP parameter space.

   hep-phPRD(2021)·45 citations
3. 03*

   QCD effects in lepton angular distributions of Drell-Yan/$Z$ production and jet discrimination

   Wen-Chen Chang🇹🇼 · Randall Evan McClellan🇺🇸 · Jen-Chieh Peng🇺🇸 · Oleg Teryaev🇷🇺

   We present a comparison of data of lepton angular distributions of Drell-Yan/$Z$ production with the fixed-order pQCD calculations by which the baseline of pQCD effects is illustrated. As for the $Z$ production, we predict that $A_0$ and $A_2$ for $Z$ plus single gluon-jet events are very different from that of $Z$ plus single quark-jet events, allowing a new experimental tool for checking various algorithms which attempt to discriminate quark jets from gluon jets. Using an intuitive geometric approach, we show that the violation of the Lam-Tung relation, appearing at large transverse-momentum region, is attributed to the presence of a non-coplanarity effect. This interpretation is consistent with the appearance of violation beyond LO-QCD effect.

   hep-phhep-exnucl-exPoS(2021)·1 citation
4. 04*

   Axion-driven hybrid inflation over a barrier

   Jinn-Ouk Gong🇰🇷 · Kwang Sik Jeong🇰🇷

   We present a scenario where an axion-like field drives inflation until a potential barrier, which keeps a waterfall field at the origin, disappears and a waterfall transition occurs. Such a barrier separates the scale of inflation from that of the waterfall transition. We find the observed spectrum of the cosmic microwave background indicates that the decay constant of the inflaton is well below the Planck scale, with the inflationary Hubble parameter spanning a wide range. Further, our model involves dark matter candidates including the inflaton itself. Also, for a complex waterfall field, we can determine cosmologically the Peccei-Quinn scale associated with the strong CP problem.

   hep-phastro-ph.COPRD(2021)·7 citations
5. 05*

   Hidden-charm pentaquarks with triple strangeness due to the ${\Omega }_c^{(\ast )}{\bar{D}}_s^{(\ast )}$ interactions

   Fu-Lai Wang🇨🇳 · Xin-Dian Yang🇨🇳 · Rui Chen🇨🇳 · Xiang Liu🇨🇳

   Motivated by the successful interpretation of these observed $P_c$ and $P_{cs}$ states under the meson-baryon molecular picture, we systematically investigate the possible hidden-charm molecular pentaquark states with triple strangeness which is due to the ${\Omega }_c^{(\ast )}{\bar{D}}_s^{(\ast )}$ interactions. We perform a dynamical calculation of the possible hidden-charm molecular pentaquarks with triple strangeness by the one-boson-exchange model, where the $S$-$D$ wave mixing effect and the coupled channel effect are taken into account in our calculation. Our results suggest that the ${\Omega }_c{\bar{D}}_s^{\ast }$ state with $J^P=3/2^{-}$ and the ${\Omega }_c^{\ast }{\bar{D}}_s^{\ast }$ state with $J^P=5/2^{-}$ can be recommended as the candidates of the hidden-charm molecular pentaquark with triple strangeness. Furthermore, we discuss the two-body hidden-charm strong decay behaviors of these possible hidden-charm molecular pentaquarks with triple strangeness by adopting the quark-interchange model. These predictions are expected to be tested at the LHCb, which can be as a potential research issue with more accumulated experimental data in near future.

   hep-phhep-exPRD(2021)·42 citations
6. 06*

   The Drell-Yan nuclear modification due to the nuclear effects of nPDFs and initial-state parton energy loss

   Li-Hua Song🇨🇳 · Peng-Qi Wang🇨🇳 · Yin-Jie Zhang🇨🇳

   By globally analyzing nuclear Drell-Yan data including all incident energies, the nuclear effects of nPDFs and initial-state parton energy loss are investigated. Based on Landau-Pomeranchuk-Migdal (LPM) regime, the calculations are carried out by means of the analytic parametrizations of quenching weights derived from the Baier-Dokshitzer-Mueller-Peign$\acute{e}$-Schiff (BDMPS) formalism and using the new EPPS16 nPDFs. It is found that the results are in good agreement with the data and the role of the energy loss effect on the suppression of Drell-Yan ratios is prominent, especially for low-mass Drell-Yan measurements. The nuclear effects of nPDFs becomes more obvious with the nuclear mass number A, the same as the energy loss effect. By global fit, the transport coefficient extracted is $\hat{q}=0.26\pm 0.04$ GeV${}^2$/fm. In addition, to avoid diminishing the QCD NLO correction on the data form of Drell-Yan ratios, the separate calculations about the Compton differential cross section ratios $R_{Fe(W)/C}(x_F)$ at 120GeV are performed, which provides a feasible way to better distinguish the gluon energy loss in Compton scattering. It is found that the role of the initial-state gluon energy loss on the suppression of Compton scattering rations is not very important and becomes disappear with the increase of $x_F$.

   hep-phCPC(2021)·3 citations
7. 07*

   Cosmic-Neutrino-Boosted Dark Matter ($\nu$BDM)

   Yongsoo Jho🇰🇷 · Jong-Chul Park🇰🇷 · Seong Chan Park🇰🇷 · Po-Yan Tseng🇰🇷

   A novel mechanism of boosting dark matter by cosmic neutrinos is proposed. The new mechanism is so significant that the arriving flux of dark matter in the mass window $1\mathrm{keV}\lesssim m_{\mathrm{DM}}\lesssim 1\mathrm{MeV}$ on Earth can be enhanced by two to four orders of magnitude compared to one only by cosmic electrons. Thereby we firstly derive conservative but still stringent bounds and future sensitivity limits for such cosmic-neutrino-boosted dark matter ($\nu$BDM) from advanced underground experiments such as Borexino, PandaX, XENON1T, and JUNO.

   hep-ph66 citations
8. 08*

   Angular analysis of bottom-flavored hadron production in semileptonic decays of polarized top quarks

   Bernd A. Kniehl🇩🇪 · S. Mohammad Moosavi Nejad🇮🇷

   We study the inclusive production of bottom-flavored hadrons from semileptonic decays of polarized top quarks at next-to-leading order in QCD using fragmentation functions recently determined from a global fit to $e^{+}{e}^{-}$ data. We provide the relevant differential decay widths at parton level in analytic form. These results fill an important gap in the theoretical interpretation of recent measurements of the top-quark polarization and the $t\bar{t}$ spin correlations using dilepton final states in proton-proton collisions at the CERN Large Hadron Collider. As an illustration, we study the distributions in the scaled bottom-hadron energy of the polarized-top-quark decay widths for different $W$-boson helicities.

   hep-phhep-exPRD(2021)·6 citations
9. 09*

   The LFU Ratio $R_{\pi }$ in the Standard Model and Beyond

   Marzia Bordone🇩🇪 · Claudia Cornella🇨🇭 · Gino Isidori🇨🇭 · Matthias König🇩🇪

   We discuss the possibility of performing precise tests of $\mu /e$ universality in $B\to \pi {\ell }^{+}{\ell }^{-}$ decays. We show that in wide regions of the dilepton invariant mass spectrum the ratio between muonic and electronic decay widths can be predicted with high accuracy, both within and beyond the Standard Model. We present numerical expressions which can be used to extract precise information on short-distance dynamics if a deviation from universality is observed in the data.

   hep-phhep-exEPJC(2021)·15 citations
10. 10*

    Coulomb corrections to two-particle interaction in artificial traps

    Peng Guo🇺🇸

    In present work, we discuss the effect of Coulomb interaction to the dynamics of two-particle system bound in various traps. The strategy of including Coulomb interaction into the quantization condition of trapped system is discussed in a general and non-perturbative manner. In most cases, Coulomb corrections to quantization condition largely rely on numerical approach or perturbation expansion. Only for some special cases, such as the spherical hard wall trap, a closed-form of quantization condition with all orders of Coulomb corrections can be obtained.

    ↳ nucl-thhep-lathep-phPRC(2021)·29 citations
11. 11*

    Gravitational waves from type II axion-like curvaton model and its implication for NANOGrav result

    Masahiro Kawasaki🇯🇵 · Hiromasa Nakatsuka🇯🇵

    The recent report of NANOGrav is gathering attention since its signal can be explained by the stochastic gravitational waves (GWs) with ${\Omega }_{\mathrm{GW}}\sim 10^{-9}$ at $f\sim 10^{-8}$Hz. The PBH formation scenario is one of the candidates for the NANOGrav signal, which can simultaneously explain the observed $30M_{\odot }$ black holes in the binary merger events in LIGO-Virgo collaboration. We focus on the type II axion-like curvaton model of the PBH formation. In type II model the complex field whose phase part is the axion rolls down from the origin of the potential. It is found that type II model achieves the broad power spectrum of the density perturbations and can simultaneously explain the LIGO-Virgo events and the NANOGrav signal. We also improve the treatment of the non-Gaussianity of perturbations in our model to accurately estimate the amplitude of the induced GWs.

    ↳ astro-ph.COhep-phJCAP(2021)·43 citations
12. 12*

    Constraints on the Coupling between Axionlike Dark Matter and Photons Using an Antiproton Superconducting Tuned Detection Circuit in a Cryogenic Penning Trap

    Jack A. Devlin🇯🇵 · Matthias J. Borchert🇯🇵 · Stefan Erlewein🇯🇵 · Markus Fleck🇯🇵 · James A. Harrington🇯🇵 · Barbara Latacz🇯🇵 · Jan Warncke🇯🇵 · Elise Wursten🇯🇵 · Matthew A. Bohman🇯🇵 · Andreas H. Mooser🇯🇵 · Christian Smorra🇯🇵 · Markus Wiesinger🇯🇵 and 8 other authors

    We constrain the coupling between axionlike particles (ALPs) and photons, measured with the superconducting resonant detection circuit of a cryogenic Penning trap. By searching the noise spectrum of our fixed-frequency resonant circuit for peaks caused by dark matter ALPs converting into photons in the strong magnetic field of the Penning-trap magnet, we are able to constrain the coupling of ALPs with masses around $2.7906-2.7914{\text{neV/c}}^2$ to $g_{a\gamma }<1\times 10^{-11}{\text{GeV}}^{-1}$. This is more than one order of magnitude lower than the best laboratory haloscope and approximately 5 times lower than the CERN axion solar telescope (CAST), setting limits in a mass and coupling range which is not constrained by astrophysical observations. Our approach can be extended to many other Penning-trap experiments and has the potential to provide broad limits in the low ALP mass range.

    ↳ astro-ph.COhep-phphysics.atom-phPRL(2021)·77 citations
13. 13*

    Extensions of the AZ-algorithm and the Package MultiIntegrate

    Jakob Ablinger🇦🇹

    We extend the (continuous) multivariate Almkvist-Zeilberger algorithm in order to apply it for instance to special Feynman integrals emerging in renormalizable Quantum field Theories. We will consider multidimensional integrals over hyperexponential integrands and try to find closed form representations in terms of nested sums and products or iterated integrals. In addition, if we fail to compute a closed form solution in full generality, we may succeed in computing the first coefficients of the Laurent series expansions of such integrals in terms of indefinite nested sums and products or iterated integrals. In this article we present the corresponding methods and algorithms. Our Mathematica package MultiIntegrate, can be considered as an enhanced implementation of the (continuous) multivariate Almkvist Zeilberger algorithm to compute recurrences or differential equations for hyperexponential integrands and integrals. Together with the summation package Sigma and the package HarmonicSums our package provides methods to compute closed form representations (or coefficients of the Laurent series expansions) of multidimensional integrals over hyperexponential integrands in terms of nested sums or iterated integrals.

    ↳ cs.SChep-phmath.CO5 citations
14. 14*

    Effect of new jet substructure measurements on Pythia8 tunes

    Deepak Kar🇿🇦 · Pratixan Sarmah🇮🇳

    This study used the recent ATLAS jet substructure measurements to see if any improvements can be made to the commonly used Pythia8 Monash and A14 tunes.

    ↳ hep-exhep-ph3 citations
15. 15*

    QCD Equation of State at Finite Chemical Potentials for Relativistic Nuclear Collisions

    Akihiko Monnai🇯🇵 · Björn Schenke🇺🇸 · Chun Shen🇺🇸

    We review the equation of state of QCD matter at finite densities. We discuss the construction of the equation of state with net baryon number, electric charge, and strangeness using the results of lattice QCD simulations and hadron resonance gas models. Its application to the hydrodynamic analyses of relativistic nuclear collisions suggests that the interplay of multiple conserved charges is important in the quantitative understanding of the dense nuclear matter created at lower beam energies. Several different models of the QCD equation of state are discussed for comparison.

    ↳ nucl-thhep-phnucl-exInt.J.Mod.Phys.A(2021)·75 citations
16. 16*

    Dimensional Reduction and (Anti) de Sitter Bounds

    Tom Rudelius🇺🇸

    Dimensional reduction has proven to be a surprisingly powerful tool for delineating the boundary between the string landscape and the swampland. Bounds from the Weak Gravity Conjecture and the Repulsive Force Conjecture, for instance, are exactly preserved under dimensional reduction. Motivated by its success in these cases, we apply a similar dimensional reduction analysis to bounds on the gradient of the scalar field potential $V$ and the mass scale $m$ of a tower of light particles in terms of the cosmological constant $\Lambda$, which ideally may pin down ambiguous $O(1)$ constants appearing in the de Sitter Conjecture and the (Anti) de Sitter Distance Conjecture, respectively. We find that this analysis distinguishes the bounds $|\nabla V|/V\ge \sqrt{4/(d-2)}$, $m\lesssim |\Lambda {|}^{1/2}$, and $m\lesssim |\Lambda {|}^{1/d}$ in $d$-dimensional Planck units. The first of these bounds precludes accelerated expansion of the universe in Einstein-dilaton gravity and is almost certainly violated in our universe, though it may apply in asymptotic limits of scalar field space. The second bound cannot be satisfied in our universe, though it is saturated in supersymmetric AdS vacua with well-understood uplifts to 10d/11d supergravity. The third bound likely has a limited range of validity in quantum gravity as well, so it may or may not apply to our universe. However, if it does apply, it suggests a possible relation between the cosmological constant and the neutrino mass, which (by the see-saw mechanism) may further provide a relation between the cosmological constant problem and the hierarchy problem. We also work out the conditions for eternal inflation in general spacetime dimensions, and we comment on the behavior of these conditions under dimensional reduction.

    ↳ hep-thgr-qchep-phJHEP(2021)·87 citations
17. 17*

    Superheavy scalar dark matter from gravitational particle production in $\alpha$-attractor models of inflation

    Siyang Ling🇺🇸 · Andrew J. Long🇺🇸

    We study the phenomenon of gravitational particle production as applied to a scalar spectator field in the context of $\alpha$-attractor inflation. Assuming that the scalar has a minimal coupling to gravity, we calculate the abundance of gravitationally-produced particles as a function of the spectator's mass $m_{\chi }$ and the inflaton's $\alpha$ parameter. If the spectator is stable and sufficiently weakly coupled, such that it does not thermalize after reheating, then a population of spin-0 particles is predicted to survive in the universe today, providing a candidate for dark matter. Inhomogeneities in the spatial distribution of dark matter correspond to an isocurvature component, which can be probed by measurements of the cosmic microwave background anisotropies. We calculate the dark matter-photon isocurvature power spectrum and by comparing with upper limits from Planck, we infer constraints on $m_{\chi }$ and $\alpha$. If the scalar spectator makes up all of the dark matter today, then for $\alpha =10$ and $T_{\text{RH}}=10^4\mathrm{GeV}$ we obtain $m_{\chi }>1.8\times 10^{13}\mathrm{GeV}\approx 1.2m_{\varphi }$, where $m_{\varphi }$ is the inflaton's mass.

    ↳ astro-ph.COhep-phPRD(2021)·64 citations
18. 18*

    Towards studying the structural differences between the pion and its radial excitation

    Xiang Gao🇺🇸 · Nikhil Karthik🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Sergey Syritsyn🇺🇸 · Yong Zhao🇺🇸

    We present an exploratory lattice QCD investigation of the differences between the valence quark structure of pion and its radial excitation $\pi (1300)$ in a fixed finite volume using the leading-twist factorization approach. We present evidences that the first pion excitation in our lattice computation is a single particle state that is likely to be the finite volume realization of $\pi (1300)$. An analysis with reasonable priors result in better estimates of the excited state PDF and the moments, wherein we find evidence that the radial excitation of pion correlates with an almost two-fold increase in the momentum fraction of valence quarks. This proof-of-principle work establishes the viability of future lattice computations incorporating larger operator basis that can resolve the structural changes accompanying hadronic excitation.

    ↳ hep-lathep-exhep-phnucl-thPRD(2021)·16 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.