Mon·Dec 30, 2019Monday·December 30, 2019

1. 01*

   Leptonic Source of Dark Matter and Radiative Majorana or Dirac Neutrino Mass

   Ernest Ma (UC Riverside)🇺🇸

   The notion of U(1) lepton number (which may only be softly broken) is applied to models of dark matter which interacts with leptons. Previous scotogenic models of Majorana or Dirac neutrino mass are shown to be derivable in this framework without additional symmetries. Only complete renormalizable theories are considered. An explicit class of models with $Z_n$ ($n\ge 5$) lepton and dark symmetry for Dirac neutrinos is derived, as well as an example of $Z_3$ dark symmetry.

   hep-phPLB(2020)·23 citations
2. 02*

   Evidence of Odderon-exchange from scaling properties of elastic scattering at TeV energies

   T. Csorgo🇭🇺 · T. Novak🇭🇺 · R. Pasechnik🇸🇪 · A. Ster🇭🇺 · I. Szanyi🇭🇺

   We study the scaling properties of the differential cross section of elastic proton-proton ($pp$) and proton-antiproton ($p\bar{p}$) collisions at high energies. We introduce a new scaling function, that scales -- within the experimental errors -- all the ISR data on elastic $pp$ scattering from $\sqrt{s}=23.5$ to $62.5$ GeV to the same universal curve. We explore the scaling properties of the differential cross-sections of the elastic $pp$ and $p\bar{p}$ collisions in a limited TeV energy range. Rescaling the TOTEM $pp$ data from $\sqrt{s}=7$ TeV to $2.76$ and $1.96$ TeV, and comparing it to D0 $p\bar{p}$ data at $1.96$ TeV, our results provide an evidence for a $t$-channel Odderon exchange at TeV energies, with a significance of at least 6.26$\sigma$. We complete this work with a model-dependent evaluation of the domain of validity of the new scaling and its violations. We find that the $H(x)$ scaling is valid, model dependently, within $200$ GeV $\le \sqrt{s}\le$ $8$ TeV, with a $-t$ range gradually narrowing with decreasing colliding energies.

   hep-phhep-exhep-thnucl-exEPJC(2021)·62 citations
3. 03*

   Primordial Black Holes in Higgs-$R^2$ Inflation as a Whole Dark Matter

   Dhong Yeon Cheong🇰🇷 · Sung Mook Lee🇰🇷 · Seong Chan Park🇰🇷

   Primordial black holes are produced in a minimal UV extension to the Higgs inflation with an included $R^2$ term. We show that for parameters consistent with Standard Model measurements and Planck observation results lead to $M_{\mathrm{PBH}}\in (10^{-16},10^{-15})M_{\odot }$ primordial black holes with significant abundance, which may consist the majority of dark matter.

   hep-phastro-ph.COgr-qchep-thJCAP(2021)·109 citations
4. 04*

   The Origin of Proton Mass from J/$\mathrm{\Psi }$ Photo-production Data

   Rong Wang🇨🇳 · Xurong Chen🇨🇳 · Jarah Evslin🇨🇳

   The trace of the stress tensor characterizes the transformation of a theory under rescaling. In quantum chromodynamics (QCD), this trace contains contributions from the bare masses of the quarks and also from a purely quantum effect, called the QCD trace anomaly. It affects all masses in the theory. We present an estimation of the QCD trace anomaly from the near-threshold J/$\mathrm{\Psi }$ photo-production data of the GlueX experiment, at JLab. We apply a vector meson dominance model to describe the photo-production of J/$\mathrm{\Psi }$ and a running strong coupling which includes the nonperturbative effects in the low ${\mu }^2$ region. Despite the large uncertainty, we find that the experimental data favors a small value of the trace anomaly parameter $b=0.07\pm 0.17$. We report the resulting proton mass decompositions at ${\mu }^2=0.41$ GeV${}^2$ and ${\mu }^2=4$ GeV${}^2$.

   hep-phEPJC(2020)·58 citations
5. 05*

   Hidden-bottom and -charm hexaquark states in QCD sum rules

   Bing-Dong Wan🇨🇳 · Liang Tang🇨🇳 · Cong-Feng Qiao🇨🇳

   In this paper, we investigate the spectra of the prospective hidden-bottom and -charm hexaquark states with quantum numbers $J^{PC}=0^{++}$, $0^{-+}$, $1^{++}$ and $1^{--}$ in the framework of QCD sum rules. By constructing appropriate interpreting currents, the QCD sum rules analyses are performed up to dimension 12 of the condensates. Results indicate that there exist two possible baryonium states in $b$-quark sector with masses $11.84\pm 0.22$ GeV and $11.72\pm 0.26$ GeV for $0^{++}$ and $1^{--}$, respectively. The corresponding hidden-charm partners are found lying respectively at $5.19\pm 0.24$ GeV and $4.78\pm 0.23$ GeV. Note that these baryonium states are all above the dibaryon thresholds, which enables their dominant decay modes could be measured at BESIII, BELLEII, and LHCb detectors.

   hep-phEPJC(2020)·49 citations
6. 06*

   Photoproduction of hidden-bottom pentaquark and related topics

   Xu Cao🇨🇳 · Feng-Kun Guo🇨🇳 · Yu-Tie Liang🇨🇳 · Jia-Jun Wu🇨🇳 · Ju-Jun Xie🇨🇳 · Ya-Ping Xie🇨🇳 · Zhi Yang🇨🇳 · Bing-Song Zou🇨🇳

   Due to the discovery of the hidden-charm pentaquark $P_c$ states by the LHCb collaboration, the interests on the candidates of hidden-bottom pentaquark $P_b$ states are increasing. They are anticipated to exist as the analogues of the $P_c$ states in the bottom sector and predicted by many models. We give an exploration of searching for a typical $P_b$ in the $\gamma p\to {\rm Y}p$ reaction, which shows a promising potential to observe it at an electron-ion collider. The possibility of searching for $P_b$ in open-bottom channels are also briefly discussed. Meanwhile, the $t$-channel non-resonant contribution, which in fact covers several interesting topics at low energies, is systematically investigated.

   hep-phnucl-thPRD(2020)·37 citations
7. 07*

   Gluon propagator and three-gluon vertex with dynamical quarks

   A. C. Aguilar🇧🇷 · F. De Soto🇪🇸 · M. N. Ferreira🇧🇷 · J. Papavassiliou🇪🇸 · J. Rodríguez-Quintero🇪🇸 · S. Zafeiropoulos🇫🇷

   We present a detailed analysis of the kinetic and mass terms associated with the Landau gauge gluon propagator in the presence of dynamical quarks, and a comprehensive dynamical study of certain special kinematic limits of the three-gluon vertex. Our approach capitalizes on results from recent lattice simulations with (2+1) domain wall fermions, a novel nonlinear treatment of the gluon mass equation, and the nonperturbative reconstruction of the longitudinal three-gluon vertex from its fundamental Slavnov-Taylor identities. Particular emphasis is placed on the persistence of the suppression displayed by certain combinations of the vertex form factors at intermediate and low momenta, already known from numerous pure Yang-Mills studies. One of our central findings is that the inclusion of dynamical quarks moderates the intensity of this phenomenon only mildly, leaving the asymptotic low-momentum behavior unaltered, but displaces the characteristic "zero crossing" deeper into the infrared region. In addition, the effect of the three-gluon vertex is explored at the level of the renormalization-group invariant combination corresponding to the effective gauge coupling, whose size is considerably reduced with respect to its counterpart obtained from the ghost-gluon vertex. The main upshot of the above considerations is the further confirmation of the tightly interwoven dynamics between the two- and three-point sectors of QCD.

   hep-phhep-lathep-thEPJC(2020)·80 citations
8. 08*

   Cosmological Constraint on Dark Photon from $N_{\mathrm{eff}}$

   Masahiro Ibe🇯🇵 · Shin Kobayashi🇯🇵 · Yuhei Nakayama🇯🇵 · Satoshi Shirai🇯🇵

   A new U(1) gauge symmetry is the simplest extension of the Standard Model and has various theoretical and phenomenological motivations. In this paper, we study the cosmological constraint on the MeV scale dark photon. After the neutrino decoupling era at $T=\mathcal{O}(1)$MeV, the decay and annihilation of the dark photon heats up the electron and photon plasma and accordingly decreases the effective number of neutrino $N_{\mathrm{eff}}$ in the recombination era. We derive a conservative lower-limit of the dark photon mass around 8.5 MeV from the current Planck data if the mixing between the dark photon and ordinary photon is larger than $\mathcal{O}(10^{-9})$. We also find that the future CMB stage-$\mathrm{I}\mathrm{V}$ experiments can probe up to 17 MeV dark photon.

   hep-phJHEP(2020)·61 citations
9. 09*

   Learning Multivariate New Physics

   Raffaele Tito D'Agnolo🇫🇷 · Gaia Grosso🇮🇹 · Maurizio Pierini🇨🇭 · Andrea Wulzer🇨🇭 · Marco Zanetti🇮🇹

   We discuss a method that employs a multilayer perceptron to detect deviations from a reference model in large multivariate datasets. Our data analysis strategy does not rely on any prior assumption on the nature of the deviation. It is designed to be sensitive to small discrepancies that arise in datasets dominated by the reference model. The main conceptual building blocks were introduced in Ref. [1]. Here we make decisive progress in the algorithm implementation and we demonstrate its applicability to problems in high energy physics. We show that the method is sensitive to putative new physics signals in di-muon final states at the LHC. We also compare our performances on toy problems with the ones of alternative methods proposed in the literature.

   hep-phhep-exEPJC(2021)·103 citations
10. 10*

    The Tensor Pomeron and Small-x Deep Inelastic Scattering

    Daniel Britzger🇩🇪 · Carlo Ewerz🇩🇪 · Sasha Glazov🇩🇪 · Otto Nachtmann🇩🇪 · Stefan Schmitt🇩🇪

    We apply the tensor-pomeron model to small-$x$ deep-inelastic lepton-proton scattering and photoproduction. Our model includes a soft and a hard tensor pomeron as well as a reggeon contribution. Data with c.m. energies $6<\sqrt{s}<318$ GeV and virtualities $Q^2<50\text{mbox}{GeV}^2$ are considered. Our fit gives a very good description of the available data in this kinematic region, including the latest HERA data for $x<0.01$. In particular, the transition region from low to high $Q^2$ is well described. Within the errors, the hard pomeron is absent in photoproduction. The intercepts of the soft and hard pomeron in the two-tensor-pomeron model are found to be $1.0935({}_{-64}^{+76})$ and $1.3008({}_{-84}^{+73})$, respectively. We argue that a vector pomeron would not give any contribution to photoproduction.

    hep-phPoS(2019)·0 citations
11. 11*

    The Optimal Strategy for ${\epsilon }^{\prime }/\epsilon$ in the SM: 2019

    Andrzej J. Buras🇩🇪

    Following the recent analysis done in collaboration with Jason Aebischer and Christoph Bobeth, I summarize the optimal, in our view, strategy for the present evaluation of the ratio ${\epsilon }^{\prime }/\epsilon$ in the Standard Model (SM). In particular, I emphasize the importance of the correct matching of the long-distance and short-distance contributions to ${\epsilon }^{\prime }/\epsilon$, which presently is only achieved by RBC-UKQCD lattice QCD collaboration and by the analytical Dual QCD approach. An mportant role play also the isospin-breaking and QED effects, which presently are best known from chiral perturbation theory, albeit still with a significant error. Finally, it is essential to include NNLO QCD corrections in order to reduce unphysical renormalization scheme and scale dependences present at the NLO level. Here ${\mu }_c$ in $m_c({\mu }_c)$ in the case of QCD penguin (QCDP) contributions and ${\mu }_t$ in $m_t({\mu }_t)$ in the case of electroweak penguin (EWP) contributions play the most important roles. Presently the error on ${\epsilon }^{\prime }/\epsilon$ is dominated by the uncertainties in the QCDP parameter $B_6^{(1/2)}$ and the isospin-breaking parameter ${\hat{\Omega }}_{\text{eff}}$ We present a table illustrating this. To be published online by the Institute of Physics Proceedings.

    hep-phhep-exhep-latJ.Phys.Conf.Ser.(2020)·6 citations
12. 12*

    Exclusive Hard Processes for Studying Hadron Structures at J-PARC

    Wen-Chen Chang🇹🇼

    With an appropriate hard scale, exclusive hadronic processes could provide novel information of the internal quark-gluon configurations of hadrons. The availability of 10-20 GeV secondary meson beam in the coming high-momentum beam line of Hadron Hall at J-PARC offers an unique opportunity to carry out the measurements of the exclusive hard processes. We address this interesting approach by two possibilities: (a) ${\pi }^{-}p\to K^0\Lambda (1405)$ for the constituent quark structure of $\Lambda (1405)$, and (b) exclusive pion-induced Drell-Yan process ${\pi }^{-}p\to {\gamma }^{\ast }n\to l^{+}{l}^{-}n$ for the generalized parton distributions (GPDs) of nucleons. Realization of such measurements at J-PARC will open up a new way of accessing the internal quark structure of exotic hadrons and also the nucleon GPDs based on a solid theoretical foundation of perturbative QCD.

    ↳ nucl-exhep-phnucl-thJPS Conf.Proc.(2021)·0 citations
13. 13*

    Supersymmetric nonlinear sigma models as anomalous gauge theories

    Aya Kondo🇯🇵 · Tomohiko Takahashi🇯🇵

    We revisit supersymmetric nonlinear sigma models on the target manifold $C{P}^{N-1}$ and $SO(N)/SO(N-2)\times U(1)$ in four dimensions. These models are formulated as gauged linear models, but it is indicated that the Wess-Zumino term should be added to the linear model since the hidden local symmetry is anomalous. Applying a procedure used for quantization of anomalous gauge theories to the nonlinear models, we determine the form of the Wess-Zumino term, by which a global symmetry in the linear model becomes smaller in the action than the conventional one. Moreover, we analyze the resulting linear model in the $1/N$ leading order. Consequently, we find that the model has a critical coupling constant similar to bosonic models. In the weak coupling regime, the $U(1)$ local symmetry is broken but supersymmetry is never broken. In contrast to the bosonic case, it is impossible to find stable vacua in the strong coupling regime as far as in the $1/N$ leading order. These results are straightforwardly generalized to the case of the hermitian symmetric space.

    ↳ hep-thhep-phPRD(2020)·2 citations
14. 14*

    Cosmological Evolution of Semilocal String Networks

    A. Achucarro🇳🇱 · A. Avgoustidis🇬🇧 · A. Lopez-Eiguren🇫🇮 · C.J.A.P. Martins🇵🇹 · J. Urrestilla🇪🇸

    Semilocal strings -- a particular limit of electroweak strings -- are an interesting example of a stable non-topological defect whose properties resemble those of their topological cousins, the Abrikosov-Nielsen-Olesen vortices. There is, however, one important difference: a network of semilocal strings will contain segments. These are 'dumbbells' whose ends behave almost like global monopoles that are strongly attracted to one another. While closed loops of string will eventually shrink and disappear, the segments can either shrink or grow, and a cosmological network of semilocal strings will reach a scaling regime. We discuss attempts to find a "thermodynamic" description of the cosmological evolution and scaling of a network of semilocal strings, by analogy with well-known descriptions for cosmic strings and for monopoles. We propose a model for the time evolution of an overall lengthscale and typical velocity for the network as well as for its segments, and some supporting (preliminary) numerical evidence.

    ↳ astro-ph.COhep-phPhil.Trans.Roy.Soc.Lond.A(2019)·2 citations
15. 15*

    Bremsstrahlung emission from nuclear reactions in compact stars

    Sergei P. Maydanyuk (1) · Kostiantyn A. Shaulskyi (2) ((1) Institute for Nuclear Research, National Academy of Sciences of Ukraine, Kyiv, Ukraine, (2) Taras Shevchenko National University of Kyiv, Ukraine)

    Bremsstrahlung emission of photons during nuclear reactions inside dense stellar medium is investigated in the paper. For that, a new model of nucleus is developed, where nuclear forces combine nucleons as bound system in dependence on deep location inside compact star. A polytropic model of stars at index $n=3$ with densities characterized from white dwarf to neutron star is used. Bremsstrahlung formalism and calculations are well tested on existed experimental information for scattering of protons of light nuclei in Earth. We find the following. (1) In neutron stars a phenomenon of dissociation of nucleus is observed --- its disintegration on individual nucleons, starting from some critical distance between this nucleus and center of star with high density. We do not observe such a phenomenon in white dwarfs. (2) In the white dwarfs, influence of stellar medium imperceptibly affects on bremsstrahlung photons. Also, we have accurate description of bremsstrahlung photons in nuclear reactions in Sun. (3) For neutron stars, influence of stellar medium is essentially more intensive and it crucially changes the bremsstrahlung spectrum. The most intensive emission is from bowel of the star, while the weakest emission is from periphery.

    ↳ nucl-thastro-phastro-ph.HEastro-ph.SR+1CPC(2025)·0 citations
16. 16*

    Light flavor baryon production from small to large collision systems at ALICE

    Domenico Colella (for the ALICE Collaboration)🇮🇹

    Studies of light hadron and nuclei production are fundamental to characterize the hot and dense fireball created in ultra-relativistic heavy ion collisions and to investigate hadronisation mechanisms at the LHC. Observables investigated as a function of the charged particle multiplicity in proton-proton and proton-lead collisions have shown features not expected and qualitatively similar to what has been observed in larger size colliding systems. The ALICE experiment, exploiting its excellent tracking and PID capabilities, has performed an extensive and systematic study of strange and non-strange hadrons, short-lived hadron resonances and light (anti-)(hyper-)nuclei. A critical overview of these results will be presented through comparison with the statistical hadronisation model.

    ↳ hep-exhep-ph0 citations
17. 17*

    Constructing a composite Higgs model with built-in large separation of scales

    Oliver Witzel🇺🇸 · Anna Hasenfratz🇺🇸

    Experimentally the existence of a light 125 GeV Higgs boson is well established but so far no other heavier resonances have been observed. Viable models to describe the Higgs boson as composite particle require hence to exhibit a large separation of scales. This occurs naturally in systems located near a conformal fixed point irrespective whether the system lies outside or inside the conformal window. We demonstrate the latter case by investigating a mass-split model with four light and six heavy flavors. By construction mass-split models exhibit a large separation of scales and feature in addition a highly constrained hadron spectrum. We present results based on the low-lying connected meson spectrum. Although the light sector is chirally broken, we show that it exhibits hyperscaling which is typical for conformal systems.

    ↳ hep-lathep-phPoS(2019)·7 citations
18. 18*

    What Could be the Observational Signature of Dark Matter in Globular Clusters?

    Elaine C. F. S. Fortes🇦🇷 · Oswaldo D. Miranda🇧🇷 · Floyd W. Stecker🇺🇸 · Carlos A. Wuensche🇧🇷

    Here we investigate the possibility that some globular clusters (GCs) harbor intermediate mass black holes (BH) in their centers and are also embedded in a low-mass dark matter (DM) halo. Up to date, there is no evidence on whether or not GCs have DM in their constitution. For standard cold DM cosmology, it is expected that GCs form with their own DM halos. Other studies investigate the possibility that GCs were initially embedded in massive DM halos that evolved during the cluster lifetime. An additional intriguing question is related to the existence of intermediate mass black holes (IMBH) in the of GCs. The determination of whether GCs hold IMBHs would be able to answer important questions about GCs formation and the circumstances that gave rise to the IMBHs. DM & IMBH in the context of GCs are interesting subjects to be studied and we will perform such studies here, assuming the coexistence of both of them in some GCs. Having such information, we perform the study possible DM signals from GCs. One important subject to be studied is the DM density profile. In the inner regions of GCs, the DM density profile is still an open question of fundamental importance to DM studies, specially for the study of radio and $\gamma$-ray emission from DM annihilation in such regions (abridged).

    ↳ astro-ph.HEhep-phJCAP(2020)·6 citations
19. 19*

    The coset construction for non-equilibrium systems

    Michael J. Landry🇺🇸

    We propose a systematic coset construction of non-equilibrium effective field theories (EFTs) governing the long-distance and late-time dynamics of relativistic, finite-temperature condensed matter systems. Our non-equilibrium coset construction makes significant advances beyond more standard coset constructions in that it takes advantage of recently-developed techniques, which allow the formulation of non-equilibrium effective actions that account for quantum and thermal fluctuations as well as dissipation. Because these systems exist at finite temperature, the EFTs live on the closed-time-path of the Schwinger-Keldysh contour. Since the coset construction and the non-equilibrium effective actions may be unfamiliar to many readers, we include brief introductions to these topics in an effort to make this paper self-contained. To demonstrate the legitimacy of this coset construction, we successfully reproduce the known EFTs for fluids and superfluids at finite temperature. Then, to demonstrate its utility, we construct novel EFTs for solids, supersolids, and four phases of liquid crystals, all at finite temperature. We thereby combine the non-equilibrium effective action and the coset construction to create a powerful tool that can be used to study many-body systems out of thermal equilibrium.

    ↳ hep-thcond-mat.othergr-qchep-phJHEP(2020)·45 citations
20. 20*

    Boundary action and profile of effective bosonic strings

    A. S. Bakry🇨🇳 · M. A. Deliyergiyev🇵🇱 · A. A. Galal🇪🇬 · M. N. Khalil🇪🇬

    The mean-square width of the energy profile of bosonic string is calculated considering two boundary terms in the effective action. The perturbative expansion of the Lorentz-invariant boundary terms at the second and the fourth order in the effective action is taken around the free Nambu-Goto string. The calculation are presented for open strings with Dirichlet boundary condition on cylinder.

    ↳ hep-thhep-lathep-phnucl-th6 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.