Mon·Nov 5, 2018Monday·November 5, 2018

1. 01*

   Vacuum stability conditions of the economical 3-3-1 model from copositivity

   B. L. Sánchez-Vega🇧🇷 · G. Gambini🇧🇷 · C. E. Alvarez-Salazar🇧🇷

   By applying copositivity criterion to the scalar potential of the economical $3-3-1$ model, we derive necessary and sufficient bounded-from-below conditions at tree level. Although these are a large number of intricate inequalities for the dimensionless parameters of the scalar potential, we present general enlightening relations in this work. Additionally, we use constraints coming from the minimization of the scalar potential by means of the orbit space method, the positivity of the squared masses of the extra scalars, the Higgs boson mass, the $Z^{\prime }$ gauge boson mass and its mixing angle with the SM $Z$ boson in order to further restrict the parameter space of this model.

   hep-phEPJC(2019)·25 citations
2. 02*

   Light vectors coupled to bosonic currents

   Jeff A. Dror🇺🇸 · Robert Lasenby🇺🇸 · Maxim Pospelov🇨🇦

   New spin-1 particles with masses below the weak scale are present in many theories of beyond Standard Model (SM) physics. In this work, we extend previous analyses by systematically considering the couplings of such a vector to the bosonic sector of the SM, focusing on models that lead to mass-mixing with the Z boson. These couplings generically lead to enhanced emission of the vector's longitudinal mode, both in Higgs decays and in flavor changing meson decays. We present bounds in the SM+X effective theory and investigate their model-dependence. For the case of Higgs decays, we point out that tree-level vector emission is, depending on the model, not always enhanced, affecting the constraints. For meson decays, which are the dominant constraints at small vector masses, we find that while $B$ decay constraints can be weakened by fine-tuning UV parameters, it is generically difficult to suppress the stringent constraints from kaon decays.

   hep-phhep-exPRD(2019)·36 citations
3. 03*

   Polarized GPDs and structure functions of $\rho$ meson

   Bao-Dong Sun🇨🇳 · Yu-Bing Dong🇨🇳

   The $\rho$ meson polarized generalized parton distribution functions, its structure functions $g_1$ and $g_2$ and its axial form factors ${\tilde{G}}_{1,2}$ are studied based on a light-front quark model for the first time. Comparing our obtained moments of $g_1$ to lattice QCD calculation, we find that our results are reasonably consistent to the Lattice predictions.

   hep-phPRD(2019)·15 citations
4. 04*

   Saving supersymmetry and dark matter WIMPs -- a new kind of dark matter candidate with well-defined mass and couplings

   Roland E. Allen🇺🇸

   Since neither supersymmetry nor dark matter WIMPs have yet been observed, pessimism about their reality has been growing. Here we discuss a new supersymmetric theory and a new dark matter candidate which are naturally consistent with current experimental results, but which imply a plethora of new phenomena awaiting discovery within the foreseeable future.

   hep-phPhys.Scripta(2019)·8 citations
5. 05*

   Searching for a charged Higgs boson with both $H^{\pm }{W}^{\mp }Z$ and $H^{\pm }tb$ couplings at the LHC

   Jian-Yong Cen🇨🇳 · Jung-Hsin Chen🇹🇼 · Xiao-Gang He🇹🇼 · Gang Li🇹🇼 · Jhih-Ying Su🇹🇼 · Wei Wang🇨🇳

   In certain new physics scenarios, a singly charged Higgs boson can couple to both fermions and $W^{\pm }Z$ at tree level. We develop new strategies beyond current experimental searches using $pp\to jj{H}^{\pm }$, $H^{\pm }\to tb$ at the Large Hadron Collider (LHC). With the effective $H^{\pm }{W}^{\mp }Z$ and $H^{\pm }tb$ couplings we perform a model-independent analysis at the collision energy $\sqrt{s}=13$~TeV with the integrated luminosity of $3{\text{ab}}^{-1}$. We derive the discovery prospects and exclusion limits for the charged Higgs boson in the mass range from 200~GeV to 1~TeV. With $|F_{WZ}|,|A_t|\sim 0.5-1.0$ and $300\text{GeV}\lesssim m_{H^{\pm }}\lesssim 400\text{GeV}$, we point out that a discovery significance of $5\sigma$ can be achieved. The constraints and projected sensitivities are also discussed in a realistic model, i.e., the modified Georgi-Machacek model without custodial symmetry. Our proposed search would provide direct evidence for a charged Higgs boson $H^{\pm }$ that couples to $W^{\pm }Z$ and $tb$, which can have better sensitivity to the couplings of $H^{\pm }{W}^{\mp }Z$ and $H^{\pm }tb$ than current searches.

   hep-phhep-exJHEP(2019)·16 citations
6. 06*

   Sensitivity of the SHiP experiment to Heavy Neutral Leptons

   SHiP Collaboration

   Heavy Neutral Leptons (HNLs) are hypothetical particles predicted by many extensions of the Standard Model. These particles can, among other things, explain the origin of neutrino masses, generate the observed matter-antimatter asymmetry in the Universe and provide a dark matter candidate. The SHiP experiment will be able to search for HNLs produced in decays of heavy mesons and travelling distances ranging between $\mathcal{O}(50\text{ m})$ and tens of kilometers before decaying. We present the sensitivity of the SHiP experiment to a number of HNL's benchmark models and provide a way to calculate the SHiP's sensitivity to HNLs for arbitrary patterns of flavour mixings. The corresponding tools and data files are also made publicly available.

   hep-phhep-exJHEP(2019)·208 citations
7. 07*

   Constituent quark number scaling from strange hadron spectra in $pp$ collisions at $\sqrt{s}=$ 13 TeV

   Jian-wei Zhang🇨🇳 · Hai-hong Li🇨🇳 · Feng-lan Shao🇨🇳 · Jun Song🇨🇳

   We show that the data of $p_T$ spectra of ${\Omega }^{-}$ and $\varphi$ at midrapidity in inelastic events in $pp$ collisions at $\sqrt{s}=$ 13 TeV exhibit a constituent quark number scaling property, which is a clear signal of quark combination mechanism at hadronization. We use a quark combination model under equal velocity combination approximation to systematically study the production of identified hadrons in $pp$ collisions at $\sqrt{s}$= 13 TeV. The midrapidity data of $p_T$ spectra of proton, $\Lambda$, ${\Xi }^{-}$, ${\Omega }^{-}$, $\varphi$ and $K^{\ast }$ in inelastic events are simultaneously well fitted by the model. The data of multiplicity dependency of yields of these hadrons are also well understood. The strong $p_T$ dependence for data of $p/\varphi$ ratio is well explained by the model, which further suggests that the production of two hadrons with similar masses is determined by their quark contents at hadronization. $p_T$ spectra of strange hadrons at midrapidity in different multiplicity classes in $pp$ collisions at $\sqrt{s}=$ 13 TeV are predicted to further test the model in the future. The midrapidity $p_T$ spectra of soft ($p_T<2$ GeV/c) strange quark and up/down quark at hadronization in $pp$ collisions at $\sqrt{s}=$ 13 TeV are extracted.

   hep-phnucl-thCPC(2020)·12 citations
8. 08*

   Cornering variants of Georgi-Machacek model using Higgs precision data

   Dipankar Das🇮🇳 · Ipsita Saha🇮🇹

   We show that in the absence of trilinear terms in the scalar potential of Georgi-Machacek model, heavy charged scalars do not necessarily decouple from the $h\to \gamma \gamma$ decay amplitude. In such scenarios, measurement of the Higgs to diphoton signal strength can place stringent constraints in the parameter space. Using the projected precisions at the High Luminosity LHC (HL-LHC) and the ILC, we find that the upper bound on the triplet vacuum expectation value can be as low as 10 GeV. We also found that when combined with the theoretical constraints from perturbative unitarity and stability, such variants may be ruled out altogether.

   hep-phPRD(2018)·23 citations
9. 09*

   $B\to P$ and $B\to V$ Form Factors from $B$-Meson Light-Cone Sum Rules beyond Leading Twist

   Nico Gubernari🇩🇪 · Ahmet Kokulu🇩🇪 · Danny van Dyk🇩🇪

   We provide results for the full set of form factors describing semileptonic $B$-meson transitions to pseudoscalar mesons $\pi$, $K$, $\bar{D}$ and vector mesons $\rho$, $K^{\ast }$, ${\bar{D}}^{\ast }$. Our results are obtained within the framework of QCD Light-Cone Sum Rules with $B$-meson distribution amplitudes. We recalculate and confirm the results for the leading-twist two-particle contributions in the literature. Furthermore, we calculate and provide new expressions for the two-particle contributions up to twist four. Following new developments for the three-particle distribution amplitudes, we calculate and provide new results for the complete set of three-particle contributions up to twist four. The form factors are computed numerically at several phase space points using up-to-date input parameters, including correlations across phase space points and form factors. We use a model ansatz for all contributing $B$-meson distribution amplitudes that is self-consistent up to twist-four accuracy. We find that the higher-twist two-particle contributions have a substantial impact on the results, and dominate over the three-particle contributions. Our numerical results, including correlations, are provided as machine-readable ancillary files. We discuss the qualitative phenomenological impact of our results on the present $b$ anomalies.

   hep-phhep-exJHEP(2019)·306 citations
10. 10*

    Quark mass function from a one-gluon-exchange-type interaction in Minkowski space

    Elmar P. Biernat🇵🇹 · Franz Gross🇺🇸 · M. T Peña🇵🇹 · Alfred Stadler🇵🇹 · Sofia Leitão🇵🇹

    We present first results for the quark mass function in Minkowski space in both the spacelike and timelike regions calculated from the same quark-antiquark interaction kernel used in the latest meson calculations using the Gross equation. This kernel consists of a Lorentz vector effective one-gluon-exchange-type interaction, a vector constant, and a mixed scalar-pseudoscalar covariant linear confining interaction that does not contribute to the mass function. We analyze the gauge dependence of our results, prove the gauge independence of the constituent quark mass and mass gap equation, and identify the Yennie gauge as the appropriate gauge to be used in CST calculations. We compare our results in the spacelike region to lattice QCD data and find good agreement.

    hep-phnucl-thPRD(2018)·17 citations
11. 11*

    The Entropy of a Jet

    Duff Neill🇺🇸 · Wouter J. Waalewijn🇳🇱

    Scattering processes often inevitably include the production of infrared states, which are highly correlated with the hard scattering event, and decohere the hard states. This can be described using the entropy of the hard reduced density matrix, which is obtained from tracing over infrared states. We determine this entropy for an asymptotically-free gauge theory by separating the Hilbert space into hard and infrared states, and calculate it in a leading-logarithmic approximation for jets. We find that the entropy increases when the resolution scales defining the hard radiation are lowered, that this entropy is related to the subjet multiplicity, and explore connections to using jet images for machine learning, and the forward-scattering density matrix of partons in a nucleon probed in deep-inelastic scattering.

    hep-phhep-thnucl-thPRL(2019)·47 citations
12. 12*

    The linear radial spectrum of scalar mesons within the QCD sum rules in the planar limit

    S. S. Afonin🇷🇺 · T. D. Solomko🇷🇺

    We discuss the radial spectrum of light scalar mesons in the framework of spectral sum rules in the large-Nc (planar) limit of QCD. Two methods based on the use of linear radial Regge trajectories are presented. A special emphasis is placed on the appearance of scalar isoscalar state near 0.5 GeV. Within the considered sum rules, the existence of this meson (which could be a large-Nc counterpart to the sigma-meson) is closely related with existence of resonances in the vector channels and on the radial scalar trajectory.

    hep-phEPJ Web Conf.(2018)·2 citations
13. 13*

    Magnetic field creation by solar mass neutrino jets

    Dharam Vir Ahluwalia🇮🇳 · Cheng-Yang Lee🇮🇳

    Parity violation and its effects for neutrinos in astrophysical contexts have been considered earlier in pioneering papers of Hawking and Vilenkin. But because even the largest magnetic moments predicted by physics beyond the Standard Model are some twelve orders of magnitude smaller than the Bohr magneton, their implications for magnetic field generation and neutrino oscillations are generally considered insignificant. Here we show that since in astrophysical scenarios a huge number of neutrinos may be emitted, the smallness of the magnetic moment, when coupled with parity violation, is compensated by the sheer number of neutrinos. The merger of neutron stars would leave behind a short pulse of electromagnetic synchrotron radiation even if the neutrino jet in the merger points away from the neutrino detectors. We show that the magnetic field can be as large as $10^6\text{mbox}Gauss$ and comment on the possibility of direct detection. Observation of such a pulse would lend strong support for neutrino magnetic moments and resolve the missing neutrino problem in neutron star mergers.

    ↳ astro-ph.HEhep-phEPL(2019)·3 citations
14. 14*

    $B\to D^{(\ast )}\ell \nu$ form factors from $N_f=2+1$ QCD with Möbius domain-wall quarks

    Takashi Kaneko🇯🇵 · Yasumichi Aoki🇯🇵 · Brian Colquhoun🇯🇵 · Hidenori Fukaya🇯🇵 · Shoji Hashimoto (JLQCD Collaboration)🇯🇵

    We report on our study of the B \to D^(*) \ell \nu semileptonic decays at zero and nonzero recoils in 2+1 flavor QCD. The Möbius domain-wall action is employed for light, charm and bottom quarks at lattice cutoffs 1/a = 2.5 and 3.6 GeV. We take bottom quark masses up to \approx 2.4 times the physical charm mass to control discretization effects. The pion mass is as low as M_\pi \sim 310 MeV. We present our preliminary results for the relevant form factors and discuss the violation of heavy quark symmetry, which is a recent important isuue on the long-standing tension in the Cabibbo-Kobayashi-Maskawa matrix element |V_{cb}| between the exclusive and inclusive decays.

    ↳ hep-lathep-phPoS(2018)·28 citations
15. 15*

    On Wilson loops for two touching circles with opposite orientation

    Harald Dorn🇩🇪

    We study the Wilson loops for contours formed by a consecutive passage of two touching circles with a common tangent, but opposite orientation. The calculations are performed in lowest nontrivial order for $\mathcal{N}=4$ SYM at weak and strong coupling and for QCD at weak coupling. After subtracting the standard linear divergence proportional to the length, as well the recently analysed spike divergence, we get for the renormalised Wilson loops $\text{mbox}log{W}_{\text{mbox}ren}=0$. The result holds for circles with different radii and arbitrary angle between the discs spanned by them.

    ↳ hep-thhep-phJ.Phys.A(2019)·5 citations
16. 16*

    Evolution of higher moments of multiplicity distribution

    Radka Sochorova🇨🇿 · Boris Tomasik🇸🇰

    Evolution of a multiplicity distribution can be described with the help of master equation. We first look at 3rd and 4th factorial moments of multiplicity distributions and derive their equilibrium values. From them central moments and other ratios can be calculated. We study the master equation for a fixed temperature, because we want to know how fast different moments of the multiplicity distribution approach their equilibrium value. Then we investigate the situation in which the temperature of the system decreases. We find out that in the non-equilibrium state, higher factorial moments differ more from their equilibrium values than the lower moments and that the behaviour of a combination of the central moments depends on the combination we choose.

    ↳ nucl-thhep-phnucl-exPoS(2019)·0 citations
17. 17*

    Kurtosis of elliptic flow fluctuations

    Rajeev S. Bhalerao🇮🇳 · Giuliano Giacalone🇫🇷 · Jean-Yves Ollitrault🇫🇷

    Elliptic flow ($v_2$) in ultrarelativistic nucleus-nucleus collisions fluctuates event to event, both in magnitude and in orientation with respect to the reaction plane. Even though the reaction plane is not known event to event in experiment, we show that the statistical properties of $v_2$ fluctuations in the reaction plane can be precisely extracted from experimental data. Previous studies have shown how to measure the mean, variance and skewness using the first three cumulants $v_2\{2\}$, $v_2\{4\}$ and $v_2\{6\}$. We complement these studies by providing a formula for the kurtosis, which requires an accurate determination of the next cumulant $v_2\{8\}$. Using existing data, we show that the kurtosis is positive for most centralities, in contrast with the kurtosis of triangular flow fluctuations, which is negative. We argue that these features are robust predictions of fluid-dynamical models.

    ↳ nucl-thhep-phnucl-exPRC(2019)·24 citations
18. 18*

    Fully relativistic treatment of light neutrinos in $N$-body simulations

    Thomas Tram🇩🇰 · Jacob Brandbyge🇩🇰 · Jeppe Dakin🇩🇰 · Steen Hannestad🇩🇰

    Cosmological $N$-body simulations are typically purely run with particles using Newtonian equations of motion. However, such simulations can be made fully consistent with general relativity using a well-defined prescription. Here, we extend the formalism previously developed for $\Lambda$CDM cosmologies with massless neutrinos to include the effects of massive, but light neutrinos. We have implemented the method in two different $N$-body codes, CONCEPT and PKDGRAV, and demonstrate that they produce consistent results. We furthermore show that we can recover all appropriate limits, including the full GR solution in linear perturbation theory at the per mille level of precision.

    ↳ astro-ph.COhep-phJCAP(2019)·52 citations
19. 19*

    Singularities in Twist-3 Quark Distributions

    Fatma Aslan🇺🇸 · Matthias Burkardt🇺🇸

    We find in one-loop calculations and spectator models that twist-3 GPDs exhibit discontinuities. In the forward limit these discontinuities grow into Dirac delta functions which are essential to satisfy the sum rules involving twist-3 PDFs. We calculate twist-3 quasi-PDFs as a function of longitudinal momentum and identify the Dirac delta function terms with momentum components in the nucleon state that do not scale as the nucleon is boosted to the infinite momentum frame.

    ↳ nucl-thhep-phPRD(2020)·32 citations
20. 20*

    Detecting Axion Dark Matter with Radio Lines from Neutron Star Populations

    Benjamin R. Safdi🇺🇸 · Zhiquan Sun🇺🇸 · Alexander Y. Chen🇺🇸

    It has been suggested that radio telescopes may be sensitive to axion dark matter that resonantly converts to radio photons in the magnetospheres surrounding neutron stars (NSs). In this work, we closely examine this possibility by calculating the radiated power from and projected sensitivity to axion dark matter conversion in ensembles of NSs within astrophysical systems like galaxies and globular clusters. We use population synthesis and evolution models to describe the spatial distributions of NSs within these systems and the distributions of NS properties. Focusing on three specific targets for illustration, the Galactic Center of the Milky Way, the globular cluster M54 in the Sagittarius dwarf galaxy, and the Andromeda galaxy, we show that narrow-band radio observations with telescopes such as the Green Bank Telescope and the future Square Kilometer Array may be able to probe the quantum chromodynamics axion over roughly two orders of magnitude in mass, starting at a fraction of a $\mu$eV.

    ↳ astro-ph.COastro-ph.HEhep-phPRD(2019)·152 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.