Thu·Jul 8, 2021Thursday·July 8, 2021

1. 01*

   Interpretation of neutral charm mesons near threshold as unparticles

   Eric Braaten🇺🇸 · Hans-Werner Hammer🇩🇪

   The existence of the $X(3872)$ resonance extremely close to the $D^{\ast 0}{\bar{D}}^0$ threshold implies that neutral charm mesons have an approximate nonrelativistic conformal symmetry. Systems consisting of these mesons with small kinetic energies produced in a short-distance reaction are unparticles in the sense that they can be created by operators with definite scaling dimensions in a nonrelativistic conformal field theory. There is a scaling region in which their energy distribution has power-law behavior with an exponent determined by the scaling dimension of the operator. The unparticle associated with two neutral charm mesons produces a peak in the recoil momentum spectrum of $K^{\pm }$ in inclusive decays of $B^{\pm }$ that has been observed. The scaling dimensions of the unparticles associated with three neutral charm mesons are calculated. They can be determined experimentally by measuring the invariant mass distributions for $X{D}^0$ or $X{D}^{\ast 0}$ in inclusive prompt production at the Large Hadron Collider.

   hep-phnucl-thPRL(2022)·14 citations
2. 02*

   Spin contribution to the dissociation of bound states in rotating medium in magnetic field

   Kirill Tuchin🇺🇸

   Magneto-rotational dissociation is the decay, by the way of tunneling, of a rotating bound state in the magnetic field. The corresponding probability was recently computed in the quasi-classical approximation using the Imaginary Time Method and was shown to increase with the angular velocity and decrease with the magnetic field strength \cite{Tuchin:2021lxl}. This letter reports the calculation of the quantum correction to the dissociation probability associated with the spin of the tunneling particle. The quasi-classical motion of spin is described by the Bargmann--Michel--Telegdi equation in the rotating frame. It is shown that the spin contribution significantly increases the dissociation probability. Applications to the Quark-Gluon Plasma are touched upon.

   hep-phnucl-thNPA(2021)·5 citations
3. 03*

   Flipped $g_{\mu }-2$

   John Ellis🇨🇳 · Jason L. Evans · Natsumi Nagata🇯🇵 · Dimitri V. Nanopoulos🇺🇸 · Keith A. Olive🇺🇸

   We analyze the possible magnitude of the supersymmetric contribution to $g_{\mu }-2$ in a flipped SU(5) GUT model. Unlike other GUT models which are severely constrained by universality relations, in flipped SU(5) the U(1) gaugino mass and the soft supersymmetry-breaking masses of right-handed sleptons are unrelated to the other gaugino, slepton and squark masses. Consequently, the lightest neutralino and the right-handed smuon may be light enough to mitigate the discrepancy between the experimental measurement of $g_{\mu }-2$ and the Standard Model calculation, in which case they may be detectable at the LHC and/or a 250 GeV $e^{+}{e}^{-}$ collider, whereas the other gauginos and sfermions are heavy enough to escape detection at the LHC.

   hep-phEPJC(2021)·20 citations
4. 04*

   Complementarity of Lepton-Charge and Forward-Backward Drell-Yan Asymmetries for Precision Electroweak Measurements and Quark Density Determinations

   Juri Fiaschi🇬🇧 · Francesco Giuli🇨🇭 · Francesco Hautmann🇧🇪 · Stefano Moretti🇬🇧

   We address the impact of future measurements of charged and neutral current Drell-Yan (DY) asymmetries and their combination on Parton Distribution Functions (PDFs) uncertainties. We quantify the reduction of PDF uncertainties using the QCD tool xFitter. We examine the effects of such reduced PDF errors on both Standard Model (SM) and Beyond SM (BSM) observables.

   hep-phSciPost Phys.Proc.(2022)·0 citations
5. 05*

   Twist-3 Gluon Fragmentation Contribution to Polarized Hyperon Production in Unpolarized Proton-Proton Collision

   Yuji Koike🇯🇵 · Kenta Yabe🇯🇵 · Shinsuke Yoshida🇨🇳

   Understanding the origin and mechanism of the transverse polarization of hyperons produced in unpolarized proton-proton collision, $pp\to {\Lambda }^{\uparrow }X$, has been one of the long-standing issues in high-energy spin physics. In the framework of the collinear factorization applicable to large-$p_T$ hadron productions, this phenomenon is a twist-3 observable which is caused by multi-parton correlations either in the initial protons or in the process of fragmentation into the hyperon. We derive the twist-3 gluon fragmentation function (FF) contribution to this process in the leading order (LO) with respect to the QCD coupling constant. Combined with the known results for the contribution from the twist-3 distribution function and the twist-3 quark FF, this completes the LO twist-3 cross section. We also found that the model independent relations among the twist-3 gluon FFs based on the QCD equation of motion and the Lorentz invariance property of the correlation functions guarantee the color gauge invariance and the frame-independence of the cross section.

   hep-phPRD(2021)·11 citations
6. 06*

   Remarks on non-perturbative three--body dynamics and its application to the $KK\bar{K}$ system

   Xu Zhang🇩🇪 · Christoph Hanhart🇩🇪 · Ulf-G. Meißner🇩🇪 · Ju-Jun Xie🇨🇳

   A formalism is discussed that allows for a straightforward treatment of the relativistic three-body problem while keeping the correct analytic structure. In particular it is demonstrated that sacrificing covariance for analyticity can be justified by the hierarchy of different contributions in the spirit of an effective field theory. For definiteness the formalism is applied to the $KK\bar{K}$ system allowing for the emergence of the $a_0(980)$ and the $f_0(980)$ as hadronic molecules. For simplicity all inelastic channels are switched off.

   hep-phhep-exnucl-thEPJA(2022)·22 citations
7. 07*

   Time-delayed electrons from neutral currents at the LHC

   Kingman Cheung🇹🇼 · Kechen Wang🇨🇳 · Zeren Simon Wang🇹🇼

   We investigate long-lived particles (LLPs) produced in pair from neutral currents and decaying into a displaced electron plus two jets at the LHC, utilizing the proposed minimum ionizing particle timing detector at CMS. We study two benchmark models: the R-parity-violating supersymmetry with the lightest neutralinos being the lightest supersymmetric particle and two different $U(1)$ extensions of the standard model with heavy neutral leptons (HNLs). The light neutralinos are produced from the standard model $Z$-boson decays via small Higgsino components, and the HNLs arise from decays of a heavy gauge boson, $Z^{\prime }$. By simulating the signal processes at the HL-LHC with the center-of-mass energy $\sqrt{s}=$ 14 TeV and integrated luminosity of 3 ab${}^{-1}$, our analyses indicate that the search strategy based on a timing trigger and the final state kinematics has the potential to probe the parameter space that is complementary to other traditional LLP search strategies such as those based on the displaced vertex.

   hep-phJHEP(2021)·11 citations
8. 08*

   Natural-Scalaron Inflation

   Alberto Salvio🇮🇹

   A pseudo Nambu-Goldstone boson (such as an axion-like particle) is a theoretically well-motivated inflaton as it features a naturally flat potential (natural inflation). This is because Goldstone's theorem protects its potential from sizable quantum corrections. Such corrections, however, generically generates an $R^2$ term in the action, which leads to another inflaton candidate because of the equivalence between the $R^2$ term and a scalar field, the scalaron, with a quasi flat potential (Starobinsky inflation). Here it is investigated a new multifield scenario in which both the scalaron and a pseudo Nambu-Goldstone boson are active (natural-scalaron inflation). For generality, also a non-minimal coupling is included, which is shown to emerge from microscopic theories. It is demonstrated that a robust inflationary attractor is present even when the masses of the two inflatons are comparable. Moreover, the presence of the scalaron allows to satisfy all observational bounds in a large region of the parameter space, unlike what happens in pure-natural inflation.

   hep-phastro-ph.COgr-qchep-thJCAP(2021)·27 citations
9. 09*

   Asymmetric Dark Matter May Not Be Light

   Eleanor Hall🇺🇸 · Robert McGehee🇺🇸 · Hitoshi Murayama🇺🇸 · Bethany Suter🇺🇸

   It is often said that asymmetric dark matter is light compared to typical weakly interacting massive particles. Here we point out a simple scheme with a neutrino portal and $\mathcal{O}(60\text{ GeV})$ asymmetric dark matter which may be ''added'' to any standard baryogenesis scenario. The dark sector contains a copy of the Standard Model gauge group, as well as (at least) one matter family, Higgs, and right-handed neutrino. After baryogenesis, some lepton asymmetry is transferred to the dark sector through the neutrino portal where dark sphalerons convert it into a dark baryon asymmetry. Dark hadrons form asymmetric dark matter and may be directly detected due to the vector portal. Surprisingly, even dark anti-neutrons may be directly detected if they have a sizeable electric dipole moment. The dark photons visibly decay at current and future experiments which probe complementary parameter space to dark matter direct detection searches. Exotic Higgs decays are excellent signals at future $e^{+}{e}^{-}$ Higgs factories.

   hep-phastro-ph.COPRD(2022)·42 citations
10. 10*

    Fractons in effective field theories for spontaneously broken translations

    Riccardo Argurio🇧🇪 · Carlos Hoyos🇪🇸 · Daniele Musso🇪🇸 · Daniel Naegels🇧🇪

    We study the concomitant breaking of spatial translations and dilatations in Ginzburg-Landau-like models, where the dynamics responsible for the symmetry breaking is described by an effective Mexican hat potential for spatial gradients. We show that there are fractonic modes with either subdimensional propagation or no propagation altogether, namely, immobility. Such class of effective field theories encompasses instances of helical superfluids and meta-fluids, where fractons can be connected to an emergent symmetry under higher moment charges, leading in turns to the trivialization of some elastic coefficients. The introduction of a finite charge density alters the mobility properties of fractons and leads to a competition between the chemical potential and the superfluid velocity in determining the gap of the dilaton. The mobility of fractons can also be altered at zero density upon considering additional higher-derivative terms.

    ↳ hep-thcond-mat.quant-gascond-mat.str-elhep-phPRD(2021)·25 citations
11. 11*

    The contribution of Galactic TeV pulsar wind nebulae to Fermi-LAT diffuse emission

    Vittoria Vecchiotti🇮🇹 · Giulia Pagliaroli🇮🇹 · Francesco Lorenzo Villante🇮🇹

    The large-scale diffuse $\gamma -$ray flux observed by Fermi-LAT in the 1-100 GeV energy range, parameterized as $\propto E^{-\Gamma }$, has a spectral index $\Gamma$ that depends on the distance from the Galactic center. This feature, if attributed to the diffuse emission produced by cosmic rays (CR) interactions with the interstellar gas, can be interpreted as the evidence of a progressive CR spectral hardening towards the Galactic center. This interpretation challenges the paradigm of uniform cosmic rays diffusion throughout the Galaxy. We report on the implications of TeV Pulsar Wind Nebulae observed by the HESS Galactic Plane Survey in the 1-100 TeV energy range for the interpretation of Fermi-LAT data. We argue that a relevant fraction of this population cannot be resolved by Fermi-LAT in the GeV domain providing a relevant contribution to the large-scale diffuse emission, viz. $\sim 30\%$ of the total diffuse $\gamma$-ray emission in the inner Galaxy. This additional component naturally accounts for a large part of the spectral index variation observed by Fermi-LAT, weakening the evidence of CR spectral hardening in the inner Galaxy.

    ↳ astro-ph.HEhep-phCommun.Phys.(2022)·25 citations
12. 12*

    On the choice of entropy variables in multifield inflation

    Michele Cicoli🇮🇹 · Veronica Guidetti🇩🇪 · Francesco Muia🇬🇧 · Francisco G. Pedro🇮🇹 · Gian Paolo Vacca🇮🇹

    We discuss the usefulness and theoretical consistency of different entropy variables used in the literature to describe isocurvature perturbations in multifield inflationary models with a generic curved field space. We clarify which is the proper entropy variable to be used to match the evolution of isocurvature modes during inflation to the one after the reheating epoch in order to compare with observational constraints. In particular, we find that commonly used variables, as the relative entropy perturbation or the one associated to the decomposition in tangent and normal perturbations with respect to the inflationary trajectory, even if more useful to perform numerical studies, can lead to results which are wrong by several orders of magnitude, or even to apparent destabilisation effects which are unphysical for cases with light kinetically coupled spectator fields.

    ↳ astro-ph.COgr-qchep-phhep-thClass.Quant.Grav.(2023)·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.