Mon·Aug 14, 2017Monday·August 14, 2017

1. 01*

   Phenomenological implications of two simple modifications to Tri-Bimaximal mixing

   Kanwaljeet S. Channey🇮🇳 · Sanjeev Kumar🇮🇳

   We study the phenomenological implications of breaking the Tri-Bimaximal (TBM) mixing in such a way that either first or second column of TBM mixing matrix remains invariant. We present two such textures and confront them with the experimental data. We give the predictions of these textures for atmospheric mixing angle ${\theta }_{23}$ and Dirac-type CP violating phase $\delta$ that will be measured in the future experiments.

   hep-phMod.Phys.Lett.A(2017)·3 citations
2. 02*

   Non-perturbative finite-temperature Yang-Mills theory

   Anton K. Cyrol🇩🇪 · Mario Mitter🇦🇹 · Jan M. Pawlowski🇩🇪 · Nils Strodthoff🇺🇸

   We present non-perturbative correlation functions in Landau-gauge Yang-Mills theory at finite temperature. The results are obtained from the functional renormalisation group within a self-consistent approximation scheme. In particular, we compute the magnetic and electric components of the gluon propagator, and the three- and four-gluon vertices. We also show the ghost propagator and the ghost-gluon vertex at finite temperature. Our results for the propagators are confronted with lattice simulations and our Debye mass is compared to hard thermal loop perturbation theory.

   hep-phhep-lathep-thPRD(2018)·90 citations
3. 03*

   Double-charming Higgs identification using machine-learning assisted jet shapes

   Alexander Lenz🇬🇧 · Michael Spannowsky🇬🇧 · Gilberto Tetlalmatzi-Xolocotzi🇳🇱

   We study the possibility of identifying a boosted resonance that decays into a charm pair against different sources of background using QCD event shapes, which are promoted to jet shapes. Using a set of jet shapes as input to a boosted decision tree, we find that observables utilizing the simultaneous presence of two charm quarks can access complementary information compared to approaches relying on two independent charm tags. Focusing on Higgs associated production with subsequent $H\to c\bar{c}$ decay and on a CP-odd scalar $A$ with $m_A\le 10$ GeV we obtain the limits $\mathcal{B}r(H\to c\bar{c})\le 6.09\%$ and $\mathcal{B}r(H\to A(\to c\bar{c})Z)\le 0.01\%$ at $95\%$ C. L..

   hep-phPRD(2018)·6 citations
4. 04*

   Transverse momentum in double parton scattering: factorisation, evolution and matching

   Maarten G. A. Buffing🇩🇪 · Markus Diehl🇩🇪 · Tomas Kasemets🇳🇱

   We give a description of double parton scattering with measured transverse momenta in the final state, extending the formalism for factorisation and resummation developed by Collins, Soper and Sterman for the production of colourless particles. After a detailed analysis of their colour structure, we derive and solve evolution equations in rapidity and renormalisation scale for the relevant soft factors and double parton distributions. We show how in the perturbative regime, transverse momentum dependent double parton distributions can be expressed in terms of simpler nonperturbative quantities and compute several of the corresponding perturbative kernels at one-loop accuracy. We then show how the coherent sum of single and double parton scattering can be simplified for perturbatively large transverse momenta, and we discuss to which order resummation can be performed with presently available results. As an auxiliary result, we derive a simple form for the square root factor in the Collins construction of transverse momentum dependent parton distributions.

   hep-phJHEP(2018)·76 citations
5. 05*

   Gauged $U(1)$ Clockwork Theory

   Hyun Min Lee🇰🇷

   We consider the gauged $U(1)$ clockwork theory with a product of multiple gauge groups and discuss the continuum limit of the theory to a massless gauged $U(1)$ with linear dilaton background in five dimensions. The localization of the lightest state of gauge fields on a site in the theory space naturally leads to exponentially small effective couplings of external matter fields localized away from the site. We discuss the implications of our general discussion with some examples, such as mediators of dark matter interactions, flavor-changing $B$-meson decays as well as D-term SUSY breaking.

   hep-phhep-thPLB(2018)·35 citations
6. 06*

   Neutral $D\to K{K}^{\ast }$ decays as discovery channels for charm CP violation

   Ulrich Nierste🇩🇪 · Stefan Schacht🇮🇹

   We point out that the CP asymmetries in the decays $D^0\to K_S{K}^{\ast 0}$ and $D^0\to K_S\overline{K}{}^{\ast 0}$ are potential discovery channels for charm CP violation in the Standard Model. We stress that no flavor tagging is necessary, the untagged CP asymmetry $a_{CP}^{\mathrm{dir}}(D\to K_S{K}^{\ast 0})$ is essentially equal to the tagged one, so that the untagged measurement comes with a significant statistical gain. Depending on the relevant strong phase, $|a_{CP}^{\text{dir, untag}}|$ can be as large as $0.003$. The CP asymmetry is dominantly generated by exchange diagrams and does not require non-vanishing penguin amplitudes. While the CP asymmetry is smaller than in the case of $D^0\to K_S{K}_S$, the experimental analysis is more efficient due to the prompt decay $K^{\ast 0}\to K^{+}{\pi }^{-}$. One may further search for favourable strong phases in the Dalitz plot in the vicinity of the $K^{\ast 0}$ peak.

   hep-phPRL(2017)·36 citations
7. 07*

   Production of $HHH$ and $HHV(V=\gamma ,Z)$ at the hadron colliders

   Pankaj Agrawal🇮🇳 · Debashis Saha🇮🇳 · Ambresh Shivaji🇧🇪

   We consider the production of two Higgs bosons in association with a gauge boson or another Higgs boson at the hadron colliders. We compute the cross sections and distributions for the processes $pp\to HHH$ and $HHZ$ within the standard model. In particular, we compute the gluon-gluon fusion one-loop contributions mediated via heavy quarks in the loop. It is the leading order contribution to $pp\to HHH$ process. To the process $pp\to HHZ$, it is next-to-next-to-leading-order (NNLO) contribution in QCD coupling. We also compare this contribution to the next-to-leading-order (NLO) QCD contribution to this process. The NNLO contribution can be similar to NLO contribution at the Large Hadron Collider (LHC), and significantly more at higher center-of-mass energy machines. We also study new physics effects in these processes by considering $ttH,HHH,HHHH,HZZ$, and $HHZZ$ interactions as anomalous. The anomalous couplings can enhance the cross sections significantly. The $gg\to HHH$ process is specially sensitive to anomalous trilinear Higgs boson self-coupling. For the $gg\to HHZ$ process, there is some modest dependence on anomalous $HZZ$ couplings.

   hep-phPRD(2018)·15 citations
8. 08*

   Muon pair production with hadronic vacuum polarization re-evaluated using precise data fits

   Vladimir Sauli🇨🇿

   Using optical theorem within sophisticated fits for exclusive hadronic productions in $e^{+}{e}^{-}$ collisions the interference between leptonic and hadronic vacuum polarization functions is considered and applied for calculation of $\mu -$pair productions below 3 GeV. Particularly, the dispersion relation for the pion production form factor was obtained, confirming a possible evidence for the light $\rho (1250)$ resonance. The inflated error was introduced and used to discriminate the quality of various phenomenological fits. Resulting hadronic vacuum polarization was compared with other conventional sources and compared with KLOE experiment for ${\mu }^{-}{\mu }^{+}$ production at $\varphi$ meson energy. Furthermore, the obtained running fine structure coupling is compared with KLOE2 experiment for radiative return ${\mu }^{-}{\mu }^{+}$ production at $\omega /\rho$ meson energy and careful analysis of the error stemming form various fits of combined data was made and discussed.

   hep-phhep-ex1 citation
9. 09*

   Directly Detecting MeV-scale Dark Matter via Solar Reflection

   Haipeng An🇺🇸 · Maxim Pospelov🇨🇦 · Josef Pradler🇦🇹 · Adam Ritz🇨🇦

   If dark matter (DM) particles are lighter than a few MeV/$c^2$ and can scatter off electrons, their interaction within the solar interior results in a considerable hardening of the spectrum of galactic dark matter received on Earth. For a large range of the mass vs. cross section parameter space, $\{m_e,{\sigma }_e\}$, the "reflected" component of the DM flux is far more energetic than the endpoint of the ambient galactic DM energy distribution, making it detectable with existing DM detectors sensitive to an energy deposition of $10-10^3$ eV. After numerically simulating the small reflected component of the DM flux, we calculate its subsequent signal due to scattering on detector electrons, deriving new constraints on ${\sigma }_e$ in the MeV and sub-MeV range using existing data from the XENON10/100, LUX, PandaX-II, and XENON1T experiments, as well as making projections for future low threshold direct detection experiments.

   hep-phPRL(2018)·176 citations
10. 10*

    Universal physics of the few-body system of two neutrons and one flavored meson

    Udit Raha🇮🇳 · Yuki Kamiya🇯🇵 · Shung-Ichi Ando🇰🇷 · Tetsuo Hyodo🇯🇵

    We investigate the $s$-wave three-body system of two neutrons and one flavored meson with total spin-isospin $J=0,I=3/2$. The meson-neutron scattering length can become infinitely large in an unphysical region of the quark mass when extrapolated from strangeness to charm in the so-called zero coupling limit. Using a low-energy cluster effective field theory, we demonstrate that the Efimov effect is manifest in the three-body system when the meson-neutron scattering length is extrapolated to the unitary limit of the two-body interaction. We thereby discuss the consequence of universal physics in the physical $K^{-}nn$ and $D^{0}nn$ systems.

    ↳ nucl-thhep-phPRC(2018)·9 citations
11. 11*

    Warm asymmetric quark matter and proto-quark stars within the confined-isospin-density-dependent mass model

    Peng-Cheng Chu🇨🇳 · Lie-Wen Chen🇨🇳

    We extend the confined-isospin-density-dependent mass (CIDDM) model to include temperature dependence of the equivalent mass for quarks. Within the CIDDM model, we study the equation of state (EOS) for $\beta$-equilibrium quark matter, quark symmetry energy, quark symmetry free energy, and the properties of quark stars at finite temperature. We find that including the temperature dependence of the equivalent mass can significantly influence the properties of the strange quark matter (SQM) as well as the quark symmetry energy, the quark symmetry free energy, and the maximum mass of quark stars at finite temperature. The mass-radius relations for different stages of the proto-quark stars (PQSs) along the star evolution are analyzed. Our results indicate that the heating (cooling) process for PQSs will increase (decrease) the maximum mass within CIDDM model by including temperature dependence of the equivalent mass for quarks.

    ↳ nucl-thhep-phPRD(2017)·23 citations
12. 12*

    Neutral kaon mixing beyond the Standard Model with nf=2+1 chiral fermions part II: Non Perturbative Renormalisation of the $\Delta F=2$ four-quark operators

    P.A. Boyle🇬🇧 · N. Garron🇬🇧 · R.J. Hudspith🇨🇦 · C. Lehner🇺🇸 · A.T. Lytle🇬🇧

    We compute the renormalisation factors (Z-matrices) of the $\Delta F=2$ four-quark operators needed for Beyond the Standard Model (BSM) kaon mixing. We work with nf=2+1 flavours of Domain-Wall fermions whose chiral-flavour properties are essential to maintain a continuum-like mixing pattern. We introduce new RI-SMOM renormalisation schemes, which we argue are better behaved compared to the commonly-used corresponding RI-MOM one. We find that, once converted to MS, the Z-factors computed through these RI-SMOM schemes are in good agreement but differ significantly from the ones computed through the RI-MOM scheme. The RI-SMOM Z-factors presented here have been used to compute the BSM neutral kaon mixing matrix elements in the companion paper [1]. We argue that the renormalisation procedure is responsible for the discrepancies observed by different collaborations, we will investigate and elucidate the origin of these differences throughout this work.

    ↳ hep-lathep-phJHEP(2017)·49 citations
13. 13*

    Astrophysical Sources of High Energy Neutrinos in the IceCube Era

    P. Meszaros🇺🇸

    High energy neutrino astrophysics has come of age with the discovery by IceCube of neutrinos in the TeV to PeV energy range attributable to extragalactic sources at cosmological distances. At such energies, astrophysical neutrinos must have their origin in cosmic ray interactions, providing information about the sources of high energy cosmic rays, as well as leading to the co-production of high energy gamma-rays. The intimate link with these latter two independently observed types of radiation provides important tools in the search for identifying and understanding the nature of their astrophysical sources. These neutrinons can provide important constraints about the cosmic ray acceleration process, and since they travel essentially unimpeded they can probe our Universe out to the farthest cosmological distances.

    ↳ astro-ph.HEhep-phAnn.Rev.Nucl.Part.Sci.(2017)·97 citations
14. 14*

    Light vector and axial mesons effective couplings to constituent quarks

    Fabio L Braghin🇧🇷

    Low energy effective couplings of baryons' constituent quarks to light vector and axial mesons are derived by considering quark polarization for a dressed one gluon exchange quark interaction. The quark field is splitted into two components, one for background constituent quarks and another one for quark-antiquark states, light mesons and the scalar chiral condensate. By considering a large quark effective mass derivative expansion, several effective coupling constants are resolved as functions of the original model parameters and of components of the quark and gluon propagators. Besides the leading single vector meson-constituent quark gauge-type effective coupling, several two-vector and axial mesons-constituent quark couplings are also obtained in the next leading order. Among these, vector and axial mesons mixings induced by constituent quark currents are found.Approximated and exact ratios between the effective coupling constants in the limit of very large quark effective mass and numerical estimates are exhibited. Numerical results of the corresponding form factors and of the (strong) vector meson quadratic radius are also presented.

    ↳ nucl-thhep-phPRD(2018)·11 citations
15. 15*

    The Metal-Poor Stellar Halo in RAVE-TGAS and its Implications for the Velocity Distribution of Dark Matter

    Jonah Herzog-Arbeitman🇺🇸 · Mariangela Lisanti🇺🇸 · Lina Necib🇺🇸

    The local velocity distribution of dark matter plays an integral role in interpreting the results from direct detection experiments. We previously showed that metal-poor halo stars serve as excellent tracers of the virialized dark matter velocity distribution using a high-resolution hydrodynamic simulation of a Milky Way--like halo. In this paper, we take advantage of the first \textit{Gaia} data release, coupled with spectroscopic measurements from the RAdial Velocity Experiment (RAVE), to study the kinematics of stars belonging to the metal-poor halo within an average distance of $\sim 5$ kpc of the Sun. We study stars with iron abundances [Fe/H]$<-1.5$ and $-1.8$ that are located more than $1.5$ kpc from the Galactic plane. Using a Gaussian mixture model analysis, we identify the stars that belong to the halo population, as well as some kinematic outliers. We find that both metallicity samples have similar velocity distributions for the halo component, within uncertainties. Assuming that the stellar halo velocities adequately trace the virialized dark matter, we study the implications for direct detection experiments. The Standard Halo Model, which is typically assumed for dark matter, is discrepant with the empirical distribution by $\sim 6\sigma$ and predicts fewer high-speed particles. As a result, the Standard Halo Model overpredicts the nuclear scattering rate for dark matter masses below $\sim 10$ GeV. The kinematic outliers that we identify may potentially be correlated with dark matter substructure, though further study is needed to establish this correspondence.

    ↳ astro-ph.GAastro-ph.COhep-phJCAP(2018)·40 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.