Wed·Mar 18, 2020Wednesday·March 18, 2020

1. 01*

   Sgoldstino signature in $hh$, $W^{+}{W}^{-}$ and $ZZ$ spectra at the LHC

   S. Demidov🇷🇺 · D. Gorbunov🇷🇺 · E. Kriukova🇷🇺

   In a supersymmetric extension of the Standard Model of particle physics (SM) with low scale of supersymmetry breaking, sgoldstino of (sub)TeV mass can be observed at the Large Hadron Collider (LHC) as a peak in diboson mass spectra. Moreover, as a singlet with respect to the SM gauge group, scalar sgoldstino can mix with the SM-like Higgs boson and interfere in all neutral channels providing with the promising signatures of new physics if superpartners are heavy. Sgoldstino couplings to the SM particles are determined by the pattern of soft supersymmetry breaking parameters. Here we concentrate on the cases with a noticeable sgoldstino contribution to di-Higgs channel. Having found a phenomenologically viable region in the model parameter space where scalar sgoldstino, produced at the LHC in gluon fusion, decays into a pair of the lightest Higgs boson we give predictions for corresponding cross section. Using the results of the LHC searches for scalar resonances we place bounds on the supersymmetry breaking scale $\sqrt{F}$ in this region of parameter space. Remarkably, in this region sgoldstino may also be observed in $W^{+}{W}^{-}$ and $ZZ$ channels, yielding independent signatures, since their signal strengths are related to that of di-Higgs channel.

   hep-phJHEP(2020)·5 citations
2. 02*

   Ultraperipheral nuclear interactions

   I.M. Dremin🇷🇺

   Large-distance ultraperipheral collisions of two relativistic ions are considered. The clouds of photons surrounding the ions are responsible for their distant electromagnetic interaction. The perturbative approach and the method of equivalent photons are described. It is shown that the total cross section of these collisions increases rapidly with increasing energy and is especially large for heavy ions. Some experimental data and their comparison with theoretical approaches are described. Further proposals are discussed.

   hep-phhep-exnucl-exnucl-thPhys.Usp.(2020)·7 citations
3. 03*

   Relativistic photoeffect for $s$ states in a central field

   E. G. Drukarev🇷🇺 · A. I. Mikhailov🇷🇺 · Kh. Yu. Rakhimov🇧🇪 · H. T. Yusupov🇺🇿

   We study the photoionization of the $s$ states in the systems bound by sufficiently weak central fields $V(r)$ for the large photon energies corresponding to the relativistic photoelectrons. We demonstrate that the energy dependence of the photoionization cross section can be obtained without solving the wave equation. We show that the shape of the energy dependence of the cross section is determined by analytical properties of the binding potential $V(r)$. We find the cross sections for the potentials $V(r)$ which have singularities in the origin, on the real axis and in the complex plane.

   hep-phphysics.atom-phquant-phEur.Phys.J.D(2020)·1 citation
4. 04*

   Predictive power of transverse-momentum-dependent distributions

   Manvir Grewal🇺🇸 · Zhong-Bo Kang🇺🇸 · Jian-Wei Qiu🇺🇸 · Andrea Signori🇺🇸

   We investigate the predictive power of transverse-momentum-dependent (TMD) distributions as a function of the light-cone momentum fraction $x$ and the hard scale $Q$ defined by the process. We apply the saddle point approximation to the unpolarized quark and gluon transverse momentum distributions and evaluate the position of the saddle point as a function of the kinematics. We determine quantitatively that the predictive power for an unpolarized transverse momentum distribution is maximal in the large-$Q$ and small-$x$ region. For cross sections the predictive power of the TMD factorization formalism is generally enhanced by considering the convolution of two distributions, and we explicitly consider the case of $Z$ and $H^0$ boson production. In the kinematic regions where the predictive power is not maximal, the distributions are sensitive to the non-perturbative hadron structure. Thus, these regions are critical for investigating hadron tomography in a three-dimensional momentum space.

   hep-phhep-exnucl-thPRD(2020)·29 citations
5. 05*

   $P$-wave bottom baryons of the $SU(3)$ flavor $6_F$

   Hui-Min Yang🇨🇳 · Hua-Xing Chen🇨🇳

   We investigate $P$-wave bottom baryons of the $SU(3)$ flavor $6_F$, and systematically study their $D$-wave decays into ground-state bottom baryons and pseudoscalar mesons. Together with [PRD91, 054034 (2015); PRD92, 114007 (2015); PRD95, 094008 (2017); EPJC80, 80 (2020)], a rather complete study is performed on both mass spectra and decay properties of $P$-wave bottom baryons, using the method of QCD sum rules and light-cone sum rules within the framework of heavy quark effective theory. Among all the possibilities, we find four ${\Sigma }_b$, four ${\Xi }_b^{\prime }$, and six ${\Omega }_b$ baryons, with limited widths and so capable of being observed. Their masses, mass splittings within the same multiplets, and decay properties are extracted (summarized in Table V) for future experimental searchings.

   hep-phhep-exPRD(2020)·46 citations
6. 06*

   Molecular picture for the $\Omega (2012)$ revisited

   Natsumi Ikeno🇯🇵 · Genaro Toledo🇲🇽 · Eulogio Oset🇪🇸

   We conduct a study of the interaction of the $\bar{K}{\Xi }^{\ast }$, $\eta \Omega$($s$-wave) and $\bar{K}\Xi$($d$-wave) channels within a coupled channel unitary approach where the transition potential between the $\bar{K}{\Xi }^{\ast }$ and $\eta \Omega$ channels is obtained from chiral Lagrangians. The transition potential between $\bar{K}{\Xi }^{\ast }$, $\eta \Omega$ and $\bar{K}\Xi$ is taken in terms of free parameters, which together with a cut off to regularize the meson-baryon loops are fitted to the $\Omega (2012)$ data. We find that all data including the recent Belle experiment on ${\Gamma }_{{\Omega }^{\ast }\to \pi \bar{K}\Xi }/{\Gamma }_{{\Omega }^{\ast }\to \bar{K}\Xi }$, are compatible with the molecular picture stemming from meson baryon interaction of these channels.

   hep-phnucl-thPRD(2020)·44 citations
7. 07*

   Revisiting the $\Omega (2012)$ as a hadronic molecule and its strong decays

   Jun-Xu Lu🇨🇳 · Chun-Hua Zeng🇨🇳 · En Wang🇨🇳 · Ju-Jun Xie🇨🇳 · Li-Sheng Geng🇨🇳

   Recently, the Belle collaboration measured the ratios of the branching fractions of the newly observed $\Omega (2012)$ excited state. They did not observe significant signals for the $\Omega (2012)\to \bar{K}{\Xi }^{\ast }(1530)\to \bar{K}\pi \Xi$ decay, and reported an upper limit for the ratio of the three body decay to the two body decay mode of $\Omega (2012)\to \bar{K}\Xi$. In this work, we revisit the newly observed $\Omega (2012)$ from the molecular perspective where this resonance appears to be a dynamically generated state with spin-parity $3/2^{-}$ from the coupled channels interactions of the $\bar{K}{\Xi }^{\ast }(1530)$ and $\eta \Omega$ in $s$-wave and $\bar{K}\Xi$ in $d$-wave. With the model parameters for the $d$-wave interaction, we show that the ratio of these decay fractions reported recently by the Belle collaboration can be easily accommodated.

   hep-phhep-exnucl-exnucl-thEPJC(2020)·38 citations
8. 08*

   Branching fractions and polarizations of $D\to V(\omega ,\rho ,K^{\ast })\ell {\nu }_{\ell }$ within QCD LCSR

   Hai-Bing Fu🇨🇳 · Wei Cheng🇨🇳 · Long Zeng🇨🇳 · Dan-Dan Hu🇨🇳 · Tao Zhong🇨🇳

   In this paper, we make a detailed study about the $D\to V$ helicity form factors (HFFs) within the framework of QCD light-cone sum rule (LCSR) up to twist-4 accuracy. After extrapolating the LCSR predictions of HFFs to the whole physical $q^2$-region, we get the longitudinal, transverse and total $|V_{cq}|$-independent decay widths of semileptonic decay $D\to V{\ell }^{+}{\nu }_{\ell }$. Meanwhile, the branching fractions of these decays are also obtained by using the $D^0(D^{+})$-meson lifetime, which agree well with the BES-III results within errors. As a further step, we also investigate the differential and mean predictions for charged lepton (vector meson) polarization in the final state $P_{\mathrm{L},\mathrm{T}}^{\ell }$ ($F_{\mathrm{L},\mathrm{T}}^{\ell }$), the forward-backward asymmetry ${\mathcal{A}}_{\mathrm{FB}}^{\ell }$, and the lepton-side convexity parameters ${\mathcal{C}}_{\mathrm{F}}^{\ell }$. Our predictions are consistent with Covariant Confining Quark Model results within the errors. Thus, we think the LCSR approach for HFFs is applicable for dealing with the $D$-meson semileptonic decays.

   hep-phPRResearch(2020)·16 citations
9. 09*

   Electron and muon $g-2$, radiative neutrino mass, and ${\ell }^{\prime }\to \ell \gamma$ in a $U(1{)}_{e-\mu }$ model

   Chuan-Hung Chen🇹🇼 · Takaaki Nomura🇰🇷

   A nonconventional $U(1{)}_{e-\mu }$ gauge model is proposed to explain the unexpected anomalous magnetic moments of the electron and muon (lepton $g-2$), where only the right-handed electron and muon in the standard model carry the $U(1{)}_{e-\mu }$ charge. Although the light lepton masses are suppressed when the gauge symmetry is spontaneously broken, they can be generated through the Yukawa couplings to newly introduced particles, such as vector-like lepton doublets and singlet, and scalar singlets. It is found that the same Yukawa couplings combined with the new scalar couplings to the Higgs can induce the radiative lepton-flavor violation processes ${\ell }^{\prime }\to \ell \gamma$ and lepton $g-2$, where the lepton $g-2$ is proportional to $m_{\ell }$. When Majorana fermions and a scalar singlet are further added into the model, the active neutrinos can obtain masses via the radiative seesaw mechanism. When the bounds from the $m_e$ and $m_{\mu }$ and the neutrino data are satisfied, we find that the electron $g-2$ can reach an order of $-10^{-12}$, and the muon $g-2$ can be an order of $10^{-9}$. In addition, when the $\mu \to e\gamma$ decay is suppressed, the resulting branching ratio for $\tau \to e\gamma$ can be of $O(10^{-8})$, and that for $\tau \to \mu \gamma$ can be as large as the current upper limit.

   hep-phhep-exNPB(2021)·53 citations
10. 10*

    Twice More On Coulomb-Nuclear Interference

    Vladimir A. Petrov🇷🇺

    This is an improved and extended exposition of the modified formulas for accounting for Coulomb-nuclear interference in hadron scattering which is intended to dispel recently claimed doubts.

    hep-ph1 citation
11. 11*

    QCD sum rule studies on the $ss\bar{s}\bar{s}$ tetraquark states of $J^{PC}=0^{-+}$

    Rui-Rui Dong🇨🇳 · Niu Su🇨🇳 · Hua-Xing Chen🇨🇳 · Er-Liang Cui🇨🇳 · Zhi-Yong Zhou🇨🇳

    We apply the method of QCD sum rules to study the $ss\bar{s}\bar{s}$ tetraquark states of $J^{PC}=0^{-+}$. We construct all the relevant $ss\bar{s}\bar{s}$ tetraquark currents, and find that there are only two independent ones. We use them to further construct two weakly-correlated mixed currents. One of them leads to reliable QCD sum rule results and the mass is extracted to be $2.51_{-0.12}^{+0.15}$ GeV, suggesting that the $X(2370)$ or the $X(2500)$ can be explained as the $ss\bar{s}\bar{s}$ tetraquark state of $J^{PC}=0^{-+}$. To verify this interpretation, we propose to further study the $\pi \pi /K\bar{K}$ invariant mass spectra of the $J/\psi \to \gamma \pi \pi {\eta }^{\prime }/\gamma K\bar{K}{\eta }^{\prime }$ decays in BESIII to examine whether there exists the $f_0(980)$ resonance.

    hep-phhep-exhep-latEPJC(2020)·25 citations
12. 12*

    Leptophilic-portal Dark Matter in the Light of AMS-02 positron excess

    Sayan Ghosh🇮🇳 · Amit Dutta Banik🇨🇳 · Eung Jin Chun🇰🇷 · Debasish Majumdar🇮🇳

    We revisit dark matter annihilation as an explanation of the positron excess reported recently by the AMS-02 satellite-borne experiment. To this end, we propose a particle dark matter model by considering a Two Higgs Doublet Model (2HDM) extended with an additional singlet boson and a singlet fermion. The additional (light) boson mixes with the pseudoscalar inherent in the 2HDM, and the singlet fermion, which is the dark matter candidate, annihilates via this bosonic portal. The dark matter candidate is made leptophilic by choosing the lepton-specific 2HDM and a suitable high value of $\tan \beta$. We identify the model parameter space which explains the muon g-2 anomaly while evading the experimental constraints. After establishing the viability of the singlet fermion to be a dark matter candidate, we calculate the positron excess produced from its annihilation to the light bosons which primarily decay to muons. Incorporating the Sommerfeld effect caused by the light mediator and an appropriate boost factor, we find that our proposed model can satisfactorily explain the positron fraction excess as well as the positron spectrum data reported by AMS-02 experiment.

    hep-phPRD(2021)·16 citations
13. 13*

    Validity of SMEFT studies of VH and VV Production at NLO

    Julien Baglio🇨🇭 · Sally Dawson🇺🇸 · Samuel Homiller🇺🇸 · Samuel D. Lane🇺🇸 · Ian M. Lewis🇺🇸

    The production of $W^{\pm }H$, $ZH$, $W^{+}{W}^{-}$, and $W^{\pm }Z$ pairs probes non-Standard-Model interactions of quarks, gauge bosons, and the Higgs boson. New effects can be parameterized in terms of an effective field theory (EFT) where the Lagrangian is expanded in terms of higher-dimension operators suppressed by increasing powers of a high scale $\Lambda$. We examine the importance of including next-to-leading-order QCD corrections in global fits to the coefficients of the EFT. The numerical implications on the fits due to different approaches to enforcing the validity of the EFT are quantified. We pay particular attention to the dependence of the fits on the expansion in $1/{\Lambda }^2$ since the differences between results calculated at $\mathcal{O}(1/{\Lambda }^2)$ and $\mathcal{O}(1/{\Lambda }^4)$ may give insight into the possible significance of dimension-8 effects.

    hep-phPRD(2020)·59 citations
14. 14*

    Collider Probes of Real Triplet Scalar Dark Matter

    Cheng-Wei Chiang🇹🇼 · Giovanna Cottin🇨🇱 · Yong Du🇺🇸 · Kaori Fuyuto🇺🇸 · Michael J. Ramsey-Musolf🇺🇸

    We study discovery prospects for a real triplet extension of the Standard Model scalar sector at the Large Hadron Collider (LHC) and a possible future 100 TeV $pp$ collider. We focus on the scenario in which the neutral triplet scalar is stable and contributes to the dark matter relic density. When produced in $pp$ collisions, the charged triplet scalar decays to the neutral component plus a soft pion or soft lepton pair, yielding a disappearing charged track in the detector. We recast current 13TeV LHC searches for disappearing tracks, and find that the LHC presently excludes a real triplet scalar lighter than 248 (275) GeV, for a mass splitting of 172 (160) MeV with $\mathcal{L}=36$fb${}^{-1}$. The reach can extend to 497 (520) GeV with the collection of $3000$fb${}^{-1}$. We extrapolate the 13 TeV analysis to a prospective 100 TeV $pp$ collider, and find that a $\sim 3$ TeV triplet scalar could be discoverable with $\mathcal{L}=30$ ab${}^{-1}$, depending on the degree to which pile up effects are under control. We also investigate the dark matter candidate in our model and corresponding present and prospective constraints from dark matter direct detection. We find that currently XENON1T can exclude a real triplet dark matter lighter than $\sim 3$ TeV for a Higgs portal coupling of order one or larger, and the future XENON20T will cover almost the entire dark matter viable parameter space except for vanishingly small portal coupling.

    hep-phJHEP(2021)·58 citations
15. 15*

    Reinterpretation of LHC Results for New Physics: Status and Recommendations after Run 2

    Waleed Abdallah🇮🇳 · Shehu AbdusSalam🇮🇷 · Azar Ahmadov🇦🇿 · Amine Ahriche🇮🇹 · Gaël Alguero🇫🇷 · Benjamin C. Allanach🇬🇧 · Jack Y. Araz🇨🇦 · Alexandre Arbey🇫🇷 · Chiara Arina🇧🇪 · Peter Athron🇦🇺 · Emanuele Bagnaschi🇨🇭 · Yang Bai🇺🇸 and 130 other authors

    We report on the status of efforts to improve the reinterpretation of searches and measurements at the LHC in terms of models for new physics, in the context of the LHC Reinterpretation Forum. We detail current experimental offerings in direct searches for new particles, measurements, technical implementations and Open Data, and provide a set of recommendations for further improving the presentation of LHC results in order to better enable reinterpretation in the future. We also provide a brief description of existing software reinterpretation frameworks and recent global analyses of new physics that make use of the current data.

    hep-phhep-exSciPost Phys.(2020)·100 citations
16. 16*

    Cosmological Hyperfluids, Torsion and Non-metricity

    Damianos Iosifidis🇬🇷

    We develop a novel model for Cosmological Hyperfluids, that is fluids with intrinsic hypermomentum that induce spacetime torsion and non-metricity. Imposing the Cosmological Principle to Metric-Affine Spaces, we present the most general covariant form of the hypermomentum tensor in an FLRW Universe along with its conservation laws and therefore construct a novel hyperfluid model for Cosmological purposes. Extending the previous model of the unconstrained hyperfluid in a Cosmological setting we establish the conservation laws for energy-momentum and hypermomentum and therefore provide the complete Cosmological setup to study non-Riemannian effects in Cosmology. With the help of this we find the forms of torsion and non-metricity that were earlier reported in the literature and also obtain the most general form of the Friedmann equations with torsion and non-metricity. We also discuss some applications of our model, make contact with the known results in the literature and point to future directions.

    ↳ gr-qchep-phhep-thEPJC(2020)·105 citations
17. 17*

    Dispersion and suppression of sound near QCD critical point

    Md Hasanujjaman🇮🇳 · Mahfuzur Rahaman🇮🇳 · Abhijit Bhattacharyya🇮🇳 · Jan-e Alam🇮🇳

    We have used second order relativistic hydrodynamics equipped with equation of state which includes the critical point to study the propagation of perturbation in a relativistic QCD fluid. Dispersion relation for the sound wave has been derived to ascertain the fate of the perturbation in the fluid near the QCD critical end point (CEP). We observe that the threshold value of the wavelength of the sound in the fluid diverges at the CEP, implying that all the modes of the perturbations are dissipated at this point. Some consequences of the suppression of sound near the critical point have been discussed.

    ↳ nucl-thhep-phPRC(2020)·9 citations
18. 18*

    Ab initio study of $({\mathbf{\nu }}_{\mathbf{\ell }},{\mathbf{\ell }}^{-})$ and $({\overline{\mathbf{\nu }}}_{\mathbf{\ell }},{\mathbf{\ell }}^{+})$ inclusive scattering in ${}^{12}$C: confronting the MiniBooNE and T2K CCQE data

    A. Lovato🇺🇸 · J. Carlson🇺🇸 · S. Gandolfi🇺🇸 · N. Rocco🇺🇸 · R. Schiavilla🇺🇸

    We carry out an ab initio calculation of the neutrino flux-folded inclusive cross sections, measured on ${}^{12}$C by the MiniBooNE and T2K collaborations in the charged-current quasielastic (CCQE) regime. The calculation is based on realistic two- and three-nucleon interactions, and on a realistic nuclear electroweak current with one-and two-nucleon terms that are constructed consistently with these interactions and reproduce low-energy electroweak transitions. Numerically exact quantum Monte Carlo methods are utilized to compute the nuclear weak response functions, by fully retaining many-body correlations in the initial and final states and interference effects between one- and two-body current contributions. We employ a nucleon axial form factor of the dipole form with ${\Lambda }_A=1.0$ or $1.15$ GeV, the latter more in line with a very recent lattice QCD determination. The calculated cross sections are found to be in good agreement with the neutrino data of MiniBooNE and T2K, and antineutrino MiniBooNE data, yielding a consistent picture of nuclei and their electroweak properties across a wide regime of energy and momenta.

    ↳ nucl-thhep-exhep-phPRX(2020)·87 citations
19. 19*

    Predictions for charmed nuclei based on $Y_{c}N$ forces inferred from lattice QCD simulations

    Johann Haidenbauer🇩🇪 · Andreas Nogga🇩🇪 · Isaac Vidaña🇮🇹

    Charmed nuclei are investigated utilizing ${\Lambda }_{c}N$ and ${\Sigma }_{c}N$ interactions that have been extrapolated from lattice QCD simulations at unphysical masses of $m_{\pi }=410$--$570$ MeV to the physical point using chiral effective field theory as guideline. Calculations of the energies of ${\Lambda }_c$ single-particle bound states for various charmed nuclei from ${}_{{\Lambda }_c}^5$Li to ${}_{{\Lambda }_c}^{209}$Bi are performed using a perturbative many-body approach. This approach allows one to determine the finite nuclei ${\Lambda }_c$ self-energy from which the energies of the different bound states can be obtained. Though the ${\Lambda }_{c}N$ interaction inferred from the lattice results is only moderately attractive, it supports the existence of charmed nuclei. Already the lightest nucleus considered is found to be bound. The spin-orbit splitting of the p- and d-wave states turns out to be small, as in the case of single $\Lambda$ hypernuclei. Additional calculations based on the Faddeev-Yakubovsky equations suggest that also $A=4$ systems involving a ${\Lambda }_c$ baryon are likely to be bound, but exclude a bound ${}_{{\Lambda }_c}^3$He state.

    ↳ nucl-thhep-phEPJA(2020)·14 citations
20. 20*

    Interacting radiation after Planck and its implications for the Hubble Tension

    Nikita Blinov🇺🇸 · Gustavo Marques-Tavares🇺🇸

    Standard cosmology predicts that prior to matter-radiation equality about 41% of the energy density was in free-streaming neutrinos. In many beyond Standard Model scenarios, however, the amount and free-streaming nature of this component is modified. For example, this occurs in models with new neutrino self-interactions or an additional dark sector with interacting light particles. We consider several extensions of the standard cosmology that include a non-free-streaming radiation component as motivated by such particle physics models and use the final Planck data release to constrain them. This release contains significant improvements in the polarization likelihood which plays an important role in distinguishing free-streaming from interacting radiation species. Fixing the total amount of energy in radiation to match the expectation from standard neutrino decoupling we find that the fraction of free-streaming radiation must be $f_{\mathrm{fs}}>0.8$ at 95% CL (combining temperature, polarization and baryon acoustic oscillation data). Allowing for arbitrary contributions of free-streaming and interacting radiation, the effective number of new non-free-streaming degrees of freedom is constrained to be $N_{\mathrm{fld}}<0.6$ at 95% CL. Cosmologies with additional radiation are also known to ease the discrepancy between the local measurement and CMB inference of the current expansion rate $H_0$. We show that including a non-free-streaming radiation component allows for a larger amount of total energy density in radiation, leading to a mild improvement of the fit to cosmological data compared to previously discussed models with only a free-streaming component.

    ↳ astro-ph.COhep-phJCAP(2020)·127 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.