Wed·Sep 12, 2018Wednesday·September 12, 2018

1. 01*

   $J/\psi$ polarization in the CGC+NRQCD approach

   Yan-Qing Ma🇨🇳 · Tomasz Stebel🇵🇱 · Raju Venugopalan🇺🇸

   We compute the $J/\psi$ polarization observables ${\lambda }_{\theta }$, ${\lambda }_{\varphi }$, ${\lambda }_{\theta \varphi }$ in a Color Glass Condensate (CGC) + nonrelativistic QCQ (NRQCD) formalism that includes contributions from both color singlet and color octet intermediate states. Our results are compared to low $p_T$ data on $J/\psi$ polarization from the LHCb and ALICE experiments on proton-proton collisions at center-of-mass energies of $\sqrt{s}=7$ TeV and 8 TeV. Our CGC+NRQCD computation provides a better description of data for $p_T\le 15$ GeV relative to extant next-to-leading (NLO) calculations within the collinear factorization framework. These results suggest that higher order computations in the CGC+NRQCD framework have the potential to greatly improve the accuracy of extracted values of the NRQCD universal long distance matrix elements.

   hep-phnucl-exnucl-thJHEP(2018)·47 citations
2. 02*

   Neutrino spectrum in SU$(3{)}_{\ell }\times$SU$(3{)}_E$ gauged lepton flavor model

   W. Sreethawong🇹🇭 · W. Treesukrat🇹🇭 · P. Uttayarat🇹🇭

   Massive neutrino is an evidence of new physics beyond the Standard Model. One of the well motivated new physics scenarios is a model with gauged lepton flavor symmetry. We investigate neutrino properties in the minimal SU$(3{)}_{\ell }\times$SU$(3{)}_E$ gauged lepton flavor model. In this model, three new species of fermions are introduced to cancel gauge anomalies. These new fermions lead to a see-saw mechanism for neutrino mass generation. We impose the constraints from perturbative unitarity in 2-2 scattering processes, as well as current experimental constraints, to obtain viable neutrino spectrum. We determine the lower bound, with the SU(3)${}_{\ell }$ gauge coupling set to 1, on the lightest neutrino mass of $3.76\times 10^{-3}(18.9\times 10^{-3})$ eV for the normal (inverted) hierarchy.

   hep-phJ.Phys.Conf.Ser.(2018)·0 citations
3. 03*

   Limits on Dark Matter Effective Field Theory Parameters with CRESST-II

   G. Angloher🇩🇪 · P. Bauer🇩🇪 · A. Bento🇩🇪 · E. Bertoldo🇩🇪 · C. Bucci🇮🇹 · L. Canonica🇩🇪 · A. D'Addabbo🇮🇹 · X. Defay🇩🇪 · S. Di Lorenzo🇮🇹 · A. Erb🇩🇪 · F. v. Feilitzsch🇩🇪 · N. Ferreiro Iachellini🇩🇪 and 33 other authors

   CRESST is a direct dark matter search experiment, aiming for an observation of nuclear recoils induced by the interaction of dark matter particles with cryogenic scintillating calcium tungstate crystals. Instead of confining ourselves to standard spin-independent and spin-dependent searches, we re-analyze data from CRESST-II using a more general effective field theory (EFT) framework. On many of the EFT coupling constants, improved exclusion limits in the low-mass region (< 3-4 GeV) are presented.

   hep-phEPJC(2019)·38 citations
4. 04*

   Effect of Hagedorn States on Isothermal Compressibility of Hadronic Matter formed in Heavy-Ion Collisions: From NICA to LHC Energies

   Arvind Khuntia🇮🇳 · Swatantra Kumar Tiwari🇮🇳 · Pramod Sharma🇮🇳 · Raghunath Sahoo🇮🇳 · Tapan Kumar Nayak🇮🇳

   In this work, we have studied the isothermal compressibility (${\kappa }_T$) as a function of temperature, baryon chemical potential and centre-of-mass energy ($\sqrt{s_{NN}}$) using hadron resonance gas (HRG) and excluded-volume hadron resonance gas (EV-HRG) models. A mass cut-off dependence of isothermal compressibility has been studied for a physical resonance gas. Further, we study the effect of heavier resonances ($>$ 2 GeV) on the isothermal compressibility by considering the Hagedorn mass spectrum, $\rho (m)\sim \exp (bm)/(m^2+m_0^2{)}^{5/4}$. Here, the parameters, $b$ and $m_0$ are extracted after comparing the results of recent lattice QCD simulations at finite baryonic chemical potential. We find a significant difference between the results obtained in EV-HRG and HRG models at a higher temperatures and higher baryochemical potentials. The inclusion of the Hagedorn mass spectrum in the partition function for hadron gas has a large effect at a higher temperature. A higher mass cut-off in the Hagedorn mass spectrum takes the isothermal compressibility to a minimum value, which occurs near the Hagedorn temperature ($T_H$). We show explicitly that at the future low energy accelerator facilities like FAIR (CBM), Darmstadt and NICA, Dubna the created matter would be incompressible compared to the high energy facilities like RHIC and LHC.

   hep-phnucl-thPRC(2019)·20 citations
5. 05*

   Hadronic uncertainties in the $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$ decay

   Marco Ciuchini🇮🇹 · Antonio M. Coutinho🇮🇹 · Marco Fedele🇫🇷 · Enrico Franco🇮🇹 · Ayan Paul🇩🇪 · Luca Silvestrini🇮🇹 · Mauro Valli🇺🇸

   Motivated by the persisting 'anomaly' in the measurement of $P_5^{\prime }$, we review hadronic uncertainties entering the angular observables of the decay $\bar{B}\to {\bar{K}}^{\ast }{\mu }^{+}{\mu }^{-}$. We argue that hadronic uncertainties could account for the present measurements. We discuss how to extract information on the non-factorizable hadronic contribution from experimental data exploiting its $q^2$ dependence and propose a parametrization optimized for this purpose. While no clear conclusion can be drawn with present experimental uncertainties, we show that future measurements should be able to pin down many hadronic parameters that we define in our parametrization.

   hep-phPoS(2018)·13 citations
6. 06*

   Phenomenology of A Little Higgs Pseudo-Axion

   Kingman Cheung🇹🇼 · Shi-Ping He🇨🇳 · Ying-nan Mao🇹🇼 · Po-Yan Tseng🇯🇵 · Chen Zhang🇹🇼

   In models where the Higgs is realized as a pseudo-Nambu-Goldstone boson (pNGB) of some global symmetry breaking, there are often remaining pNGBs of some $U(1)$ groups (called `pseudo-axions'), which could lead to smoking gun signatures of such scenarios and provide important clues on the electroweak symmetry breaking mechanism. As a concrete example, we investigate the phenomenology of the pseudo-axion in the anomaly-free Simplest Little Higgs (SLH) model. After clarifying a subtle issue related to the effect of symmetric vector-scalar-scalar (VSS) vertices (e.g. $Z_{\mu }(H{\partial }^{\mu }\eta +\eta {\partial }^{\mu }H)$), we show that for natural region in the parameter space, the SLH pseudo-axion is top-philic, decaying almost exclusively to a pair of top quarks. The direct and indirect (i.e. via heavy particle decay) production of such a pseudo-axion at the $14\text{mbox}TeV$ (HL-)LHC turn out to suffer from either large backgrounds or small rates, making its detection quite challenging. A $pp$ collider with higher energy and luminosity, such as the $27\text{mbox}TeV$ HE-LHC, or even the $100\text{mbox}TeV$ FCC-hh or SppC, is therefore motivated to capture the trace of such a pNGB.

   hep-phPRD(2018)·4 citations
7. 07*

   Importance of mesons in light-by-light scattering in ultraperipheral lead-lead collisions at the LHC

   Mariola Klusek-Gawenda🇵🇱

   Possibility of PbPb$\to$PbPb$\gamma \gamma$ measurement at smaller (< 5 GeV) diphoton invariant mass will be presented. Analysis focuses only on ultraperipheral heavy-ion collisions. This estimate shows that the $\gamma \gamma \to \gamma \gamma$ collisions can be measured at the LHC by ALICE and LHCb experiments for diphoton invariant mass $>$ 2 GeV. Predictions for the $\gamma \gamma \to \eta ,{\eta }^{\prime }\to \gamma \gamma$ resonance scattering shows that these resonances can be measured with rather good statistics. A~possible observation of peaks related to intermediate $\eta$, ${\eta }^{\prime }(958)$, ${\eta }_c(1S)$, ${\eta }_c(2S)$, ${\chi }_{c0}(1P)$ mesons will be presented too. Attempts of reduction of background which comes from dipion production will be considered.

   hep-phEPJ Web Conf.(2019)·11 citations
8. 08*

   Calculation of the Z+jet cross section including transverse momenta of initial partons

   M. Deak🇵🇱 · A. van Hameren🇵🇱 · H. Jung🇩🇪 · A. Kusina🇵🇱 · K. Kutak🇵🇱 · M. Serino🇮🇱

   We perform calculations of Z+jet cross-section taking into account the transverse momenta of the initial partons. Transverse Momentum Dependent (TMD) parton densities obtained with the Parton Branching method are used and higher order corrections are included via TMD parton showers in the initial state. The predictions are compared to measurements of forward Z+jet production of the LHCb collaboration at $\sqrt{s}=7$ TeV. We show that the results obtained in kT-factorization are in good agreement with results obtained from a NLO calculation matched with traditional parton showers. We also demonstrate that in the forward rapidity region, kT-factorization and hybrid factorization predictions agree with each other.

   hep-phPRD(2019)·31 citations
9. 09*

   Energy dependent kinetic freeze-out temperature and transverse flow velocity in high energy collisions

   Li-Li Li🇨🇳 · Fu-Hu Liu🇨🇳

   Transverse momentum spectra of negative and positive pions produced at mid-(pseudo)rapidity in inelastic or non-single-diffractive proton-proton collisions and in central nucleus-nucleus collisions over an energy range from a few GeV to above 10 TeV are analyzed by a (two-component) blast-wave model with Boltzmann-Gibbs statistics and with Tsallis statistics respectively. The model results are in similarly well agreement with the experimental data measured by a few productive collaborations who work at the Heavy Ion Synchrotron (SIS), Super Proton Synchrotron (SPS), Relativistic Heavy Ion Collider (RHIC), and Large Hadron Collider (LHC), respectively. The energy dependent kinetic freeze-out temperature and transverse flow velocity are obtained and analyzed. Both the quantities have quick increase from the SIS to SPS, and slight increase or approximate invariability from the top RHIC to LHC. Around the energy bridge from the SPS to RHIC, the considered quantities in proton-proton collisions obtained by the blast-wave model with Boltzmann-Gibbs statistics show more complex energy dependent behavior comparing with the results in other three cases.

   hep-phhep-exnucl-exnucl-thEPJA(2018)·27 citations
10. 10*

    $SO(10)\to SU(5)\times U(1{)}_{\chi }$ as the Origin of Dark Matter

    Ernest Ma (UCR & HKUST/JCIAS)🇺🇸

    In the decomposition of $SO(10)$ grand unification to $SU(5)\times U(1{)}_{\chi }$, two desirable features are obtained with the addition of one colored fermion octet $\Omega$, one electroweak fermion triplet $\Sigma$ and one complex scalar triplet $S$ to the particle content of the standard model with two Higgs doublets. They are (1) gauge coupling unification of $SU(3{)}_C\times SU(2{)}_L\times U(1{)}_Y$ to $SU(5)$, and (2) the automatic (predestined) emergence of dark matter, i.e. $\Omega$, $\Sigma$ and $S$, with dark parity given by $(-1{)}^{Q_{\chi }+2j}$. It suggests that $U(1{)}_{\chi }$ may well be the underlying symmetry of the dark sector.

    hep-phPRD(2018)·17 citations
11. 11*

    Rho Meson spectral function in hot asymmetric nuclear matter

    P.C. Raje Bhageerathi🇮🇳

    The rho meson spectral function in hot and dense asymmetric nuclear matter (number densities of proton and neutron different) is evaluated in an effective chiral SU(3) model within the mean field approximation (MFA). The dependence of the vector meson masses on density and temperature, their variation with the asymmetry parameter, the form of the spectral function when the p <-> n symmetry is broken are studied. One can observe clear splitting of the longitudinal and the transverse modes among the rho isospin multiplets. The role of a running tensor coupling on the spectral function is also studied.

    hep-phnucl-thEPJA(2019)·1 citation
12. 12*

    Polarization observables in $e^{+}{e}^{-}$ annihilation to a baryon-antibaryon pair

    Elisabetta Perotti🇸🇪 · Göran Fäldt🇸🇪 · Andrzej Kupść🇸🇪 · Stefan Leupold (Uppsala U.)🇸🇪 · Jiao Jiao Song (Shandong U. and Beijing, Inst. High Energy Phys.)🇨🇳

    Using the helicity formalism of Jacob and Wick we derive spin density matrices of baryon antibaryon pairs produced in $e^{+}{e}^{-}$ annihilation. We consider the production of pairs with spins $1/2+\overline{1/2}$, $1/2+\overline{3/2}$ (+c.c.) and $3/2+\overline{3/2}$. We provide modular expressions to include chains of weak hadronic two-body decays of the produced hyperons. The expressions are suitable for the analysis of high statistics data from $J/\psi$ and $\psi (2S)$ decays at $e^{+}{e}^{-}$ colliders, by fits to the fully differential angular distributions of the measured particles. We illustrate the method by examples, such as the inclusive measurement of the $e^{+}{e}^{-}\to \psi (2S)\to {\Omega }^{-}{\bar{\Omega }}^{+}$ process where one decay chain ${\Omega }^{-}\to \Lambda K^{-}$ followed by $\Lambda \to p{\pi }^{-}$ is considered. Finally we show that the inclusive angular distributions can be used to test spin assignment of the produced baryons.

    hep-phhep-exnucl-exPRD(2019)·118 citations
13. 13*

    High-Energy Limit of Mass-Suppressed Amplitudes in Gauge Theories

    Tao Liu🇨🇦 · Alexander A. Penin🇨🇦

    We present a detailed analysis of the factorization and all-order resummation of the double-logarithmic radiative corrections which determine the asymptotic behavior of the gauge theory amplitudes suppressed by the leading power of the fermion mass in the limit of high-energy fixed-angle scattering. The result is applied to estimate the bottom quark mediated contribution to the Higgs boson production in gluon fusion.

    hep-phhep-thJHEP(2018)·59 citations
14. 14*

    Properties of Discrete Black Hole Hair

    Isabel Garcia Garcia🇺🇸

    We revisit the physical effects of discrete ${\mathbb{Z}}_p$ gauge charge on black hole thermodynamics, building on the seminal work of Coleman, Preskill, and Wilczek. Realising the discrete theory from the spontaneous breaking of an Abelian gauge theory, we consider the two limiting cases of interest, depending on whether the Compton wavelength of the massive vector is much smaller or much larger than the size of the black hole -- the so-called thin- and thick-string limits respectively. We find that the qualitative effect of discrete hair on the mass-temperature relationship is the same in both regimes, and similar to that of unbroken $U(1)$ charge: namely, a black hole carrying discrete gauge charge is always colder than its uncharged counterpart. In the thick-string limit, our conclusions bring into question some of the results of Coleman et al., as we discuss. Further, by considering the system to be enclosed within a finite cavity, we argue how the unbroken limit may be smoothly defined, and the unscreened electric field of the standard Reissner-Nordstrom solution recovered.

    ↳ gr-qchep-phhep-thJHEP(2019)·7 citations
15. 15*

    Quantum no-scale regimes and string moduli

    Herve Partouche🇫🇷

    We review that in perturbative string theory, flat, homogeneous and isotropic cosmological evolutions found in no-scale models at the quantum level can enter into "quantum no-scale regimes" (QNSRs). When this is the case, the quantum effective potential is dominated by the classical kinetic energies of the no-scale modulus, dilaton and moduli not involved in the supersymmetry breaking. As a result, the evolutions approach the classical ones, where the no-scale structure is exact. When the 1-loop potential is positive, a global attractor mechanism forces the initially expanding solutions to enter the QNSR describing a flat, ever-expanding universe. On the contrary, when the potential can reach negative values, the internal moduli induce in most cases some kind of instability of the growing universe. The latter stops expanding and eventually collapses, unless the initial conditions are tuned in a tiny region of the phase space. Finally, in QNSR, no gauge instability takes place, regardless of the details of the potential.

    ↳ hep-thgr-qchep-phUniverse(2018)·11 citations
16. 16*

    Measuring the Hubble constant and spatial curvature from supernova apparent magnitude, baryon acoustic oscillation, and Hubble parameter data

    Chan-Gyung Park🇰🇷 · Bharat Ratra🇺🇸

    Cosmic microwave background (CMB) anisotropy (spatial inhomogeneity) data provide the tightest constraints on the Hubble constant, matter density, spatial curvature, and dark energy dynamics. Other data, sensitive to the evolution of only the spatially homogeneous part of the cosmological model, such as Type Ia supernova apparent magnitude, baryon acoustic oscillation distance, and Hubble parameter measurements, can be used in conjunction with the CMB data to more tightly constrain parameters. Recent joint analyses of CMB and such non-CMB data indicate that slightly closed spatial hypersurfaces are favored in nonflat untilted inflation models and that dark energy dynamics cannot be ruled out, and favor a smaller Hubble constant. We show that the constraints that follow from these non-CMB data alone are consistent with those that follow from the CMB data alone and so also consistent with, but weaker than, those that follow from the joint analyses of the CMB and non-CMB data.

    ↳ astro-ph.COgr-qchep-phhep-thAstrophys.Space Sci.(2019)·94 citations
17. 17*

    Higher derivative three-form gauge theories and their supersymmetric extension

    Muneto Nitta🇯🇵 · Ryo Yokokura🇯🇵

    We investigate three-form gauge theories with higher derivative interactions and their supersymmetric extensions in four space-time dimensions. For the bosonic three-form gauge theories, we show that derivatives on the field strength of the 3-form gauge field yield a tachyon as far as the Lagrangian contains a quadratic kinetic term, while such the term with opposite sign gives rise to a ghost. We confirm that there is neither a tachyon nor a ghost when all higher derivative terms are given by functions of the field strength. For this ghost/tachyon-free Lagrangian, we determine the boundary term necessary for the consistency between the equation of motion and energy-momentum tensor. For supersymmetric extensions, we present ghost/tachyon-free higher derivative interactions of arbitrary order of the field strength and corresponding boundary terms as well.

    ↳ hep-thhep-phJHEP(2018)·21 citations
18. 18*

    A note on Single-field Inflation and the Swampland Criteria

    Suratna Das🇮🇳

    The recently proposed Swampland Criteria aim to evade any (meta-)stable de Sitter constructions within String landscapes, making it difficult to accommodate accelerating phases, like dark energy domination and inflationary epoch, in cosmology. In this note, we analyse the status of various models of single field slow-roll inflation given the old as well as the refined Swampland conjectures, which constrain the form of scalar potentials in any low energy effective field theory residing in the landscapes. In particular, we note that Warm Inflation turns out to be the most befitting scenario as long as lifting the tensions with Swampland Criteria are concerned.

    ↳ hep-thastro-ph.COgr-qchep-phPRD(2019)·109 citations
19. 19*

    Production of Light Nuclei at Thermal Freezeout in Heavy-Ion Collisions

    Xinyuan Xu🇺🇸 · Ralf Rapp🇺🇸

    We revisit the problem of the production of light atomic nuclei in ultrarelativistic heavy-ion collisions. While their production systematics is well produced by hadro-chemical freezeout at temperatures near the QCD pseudo-critical temperature, their small binding energies of a few MeV per nucleon suggest that they cannot survive as bound states under these conditions. Here, we adopt the concept of effective chemical potentials in the hadronic evolution from chemical to thermal freezeout (at typically $T_{\mathrm{fo}}$$\simeq$100\,MeV), which, despite frequent elastic rescatterings in hadronic matter, conserves the effective numbers of particles which are stable under strong interactions, most notably pions, kaons and nucleons. It turns out that the large chemical potentials that build up for antibaryons result in thermal abundances of light nuclei and antinuclei, formed at thermal freezeout, which essentially agree with the ones evaluated at chemical freezeout. Together with their transverse-momentum spectra, which also indicate a kinetic freezeout near $T_{\mathrm{fo}}$, this provides a natural explanation for their production systematics without postulating their survival at high temperatures.

    ↳ nucl-thhep-phnucl-exEPJA(2019)·34 citations
20. 20*

    The self-dual classical double copy, and the Eguchi-Hanson instanton

    David S. Berman🇬🇧 · Erick Chacón🇲🇽 · Andrés Luna🇺🇸 · Chris D. White🇬🇧

    The double copy is a map from non-abelian gauge theories to gravity, that has been demonstrated both for scattering amplitudes and exact classical solutions. In this study, we reconsider the double copy for exact solutions that are self-dual in either the gauge or gravity theory. In this case, one may formulate a general double copy in terms of a certain differential operator, which generates the gauge and gravity solutions from a harmonic function residing in a biadjoint scalar theory. As an illustration, we examine the single copy of the well-known Eguchi-Hanson instanton in gravity. The gauge field thus obtained represents an abelian-like object whose field is dipole-like at large distances, and which has no magnetic or electric charge.

    ↳ hep-thgr-qchep-phJHEP(2019)·151 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.