Tue·Jun 6, 2017Tuesday·June 6, 2017

1. 01*

   Dark matter candidate with well-defined mass and couplings

   Roland E. Allen🇺🇸 · Aritra Saha🇺🇸

   We propose a Higgs-related but spin $1/2$ dark matter candidate with a mass that is comparable to that of the Higgs. This particle is a WIMP with an R-parity of $-1$, but it can be distinguished from a neutralino by its unconventional couplings to W and Z bosons. Charged spin 1/2 particles of a new kind are also predicted at higher energy.

   hep-phMod.Phys.Lett.A(2017)·10 citations
2. 02*

   New Physics in Flavour Observables

   Andreas Crivellin🇨🇭

   LHCb found hints for physics beyond the Standard Model (SM) in $B\to K^{\ast }{\mu }^{+}{\mu }^{-}$, $R(K)$ and $B_s\to \varphi {\mu }^{+}{\mu }^{-}$. These intriguing hints for NP have recently been confirmed by the LHCb measurement of $R(K^{\ast })$ giving a combined significance for NP above the $5\sigma$ level. In addition, the BABAR, BELLE and LHCb results for $B\to D^{(\ast )}\tau \nu$ also point towards lepton flavour universality (LFU) violating new physics (NP). Furthermore, there is the long-standing discrepancy between the measurement and the theory prediction of the anomalous magnetic moment of the muon ($a_{\mu }$) at the $3\sigma$ level. Concerning NP effects, $b\to s{\mu }^{+}{\mu }^{-}$ data can be naturally explained with a new neutral gauge bosons, i.e. a $Z^{\prime }$ but also with heavy new scalars and fermions contributing via box diagrams. Another promising solution to $b\to s{\mu }^{+}{\mu }^{-}$, which can also explain $B\to D^{(\ast )}\tau \nu$, are leptoquarks. Interestingly, leptoquarks provide also a viable explanation of $a_{\mu }$ which can be tested via correlated effects in $Z\to {\mu }^{+}{\mu }^{-}$ at future colliders. Considering leptoquark models, we show that an explanation of $B\to D^{(\ast )}\tau \nu$ predicts an enhancement of $b\to s{\tau }^{+}{\tau }^{-}$ processes by around three orders of magnitude compared to the SM. In case of a simultaneous explanation of $B\to D^{(\ast )}\tau \nu$ and $b\to s{\mu }^{+}{\mu }^{-}$ data, sizable effects in $b\to s\tau \mu$ processes are predicted.

   hep-phhep-ex3 citations
3. 03*

   Phase structure and propagators at nonvanishing temperature for QCD and QCD-like theories

   Romain Contant🇦🇹 · Markus Q. Huber🇦🇹

   We investigate the universality of truncation schemes for Dyson-Schwinger equations developed for quantum chromodynamics in theories which differ from quantum chromodynamics only in the gauge group. Our specific choices are the gauge groups $SU(2)$ and $G_2$, for which lattice calculations at nonvanishing chemical potential are possible. Thus, corresponding calculations can provide benchmarks for testing calculations with functional equations. We calculate the quark and gluon propagators and determine the chiral and dual chiral condensates at vanishing density to determine the confinement/deconfinement and chiral transitions, respectively. We can reproduce the expected type of transitions in the quenched and unquenched cases. In general, all three theories react very similarly to modifications of the employed model for the quark-gluon vertex.

   hep-phhep-lathep-thPRD(2017)·28 citations
4. 04*

   Generalized ${\mathbb{Z}}_2\times {\mathbb{Z}}_2$ in Scaling neutrino Majorana mass matrix and baryogenesis via flavored leptogenesis

   Roopam Sinha🇮🇳 · Rome Samanta🇮🇳 · Ambar Ghosal🇮🇳

   We investigate the consequences of a generalized ${\mathbb{Z}}_2\times {\mathbb{Z}}_2$ symmetry on a scaling neutrino Majorana mass matrix. It enables us to determine definite analytical relations between the mixing angles ${\theta }_{12}$ and ${\theta }_{13}$, maximal CP violation for the Dirac type and vanishing for the Majorana type. Beside the other testable predictions on the low energy neutrino parameters such as $\beta {\beta }_{0\nu }$ decay matrix element $|M_{ee}|$ and the light neutrino masses $m_{1,2,3}$, the model also has intriguing consequences from the perspective of leptogenesis. With the assumption that the required CP violation for leptogenesis is created by the decay of lightest ($N_1$) of the heavy Majorana neutrinos, only $\tau$-flavored leptogenesis scenario is found to be allowed in this model. For a normal (inverted) ordering of light neutrino masses, ${\theta }_{23}$ is found be less (greater) than its maximal value, for the final baryon asymmetry $Y_B$ to be in the observed range. Besides, an upper and a lower bound on the mass of $N_1$ have also been estimated. Effect of the heavier neutrinos $N_{2,3}$ on final $Y_B$ has been worked out subsequently. The predictions of this model will be tested in the experiments such as nEXO, LEGEND, GERDA-II, T2K, NO$\nu$A, DUNE etc.

   hep-phJHEP(2017)·13 citations
5. 05*

   Isospin analysis of $B\to D^{\ast }\bar{D}K$ and the absence of the $Z_c(3900)$ in $B$ decays

   Zhi Yang🇩🇪 · Qian Wang🇩🇪 · Ulf-G. Meißner🇩🇪

   We study the isospin amplitudes in the exclusive $B$ to $D^{\ast }\bar{D}K$ decay process and fit the available $D^{\ast 0}{\bar{D}}^0$ invariant mass distributions near threshold. The analysis demonstrates that the production of the isospin triplet $D^{\ast }\bar{D}$ state is highly suppressed compared to the isospin singlet one. That explains why the $Z_c(3900)$ has not been found in $B$ decays. In addition, the production of the negative charge-parity state might be further suppressed in the heavy quark limit. These two reasons which are based on the molecular assumption offer the first explanation why the $Z_c(3900)$ is absent in $B$ decays. Further studies of the absence from both the experimental and the theoretical side is extremely important for understanding the nature of the $X(3872)$ and the $Z_c(3900)$.

   hep-phPLB(2017)·5 citations
6. 06*

   Higgs Boson Plus Dijets: Higher Order Corrections

   Jeppe R. Andersen🇬🇧 · Tuomas Hapola🇬🇧 · Andreas Maier🇬🇧 · Jennifer M. Smillie🇬🇧

   The gluon fusion component of Higgs-boson production in association with dijets is of particular interest because it both (a) allows for a study of the CP-structure of the Higgs-boson couplings to gluons, and (b) provides a background to the otherwise clean study of Higgs-boson production through vector-boson fusion. The degree to which this background can be controlled, and the CP-structure of the gluon-Higgs coupling extracted, both depend on the successful description of the perturbative corrections to the gluon-fusion process. High Energy Jets (HEJ) provides all-order, perturbative predictions for multi-jet processes at hadron colliders at a fully exclusive, partonic level. We develop the framework of HEJ to include the process of Higgs-boson production in association with at least two jets. We discuss the logarithmic accuracy obtained in the underlying all-order results, and calculate the first next-to-leading corrections to the framework of HEJ, thereby significantly reducing the corrections which arise by matching to and merging fixed-order results. Finally, we compare predictions for relevant observables obtained with NLO and HEJ. We observe that the selection criteria commonly used for isolating the vector-boson fusion component suppresses the gluon-fusion component even further than predicted at NLO.

   hep-phJHEP(2017)·30 citations
7. 07*

   Study of $\mathbf{D}\to {\mathbf{a}}_0(980){\mathbf{e}}^{+}{\mathbf{\nu }}_{\mathbf{e}}$ decay in the light-cone sum rules approach

   Xiao-Dong Cheng🇨🇳 · Hai-Bo Li🇨🇳 · Bin Wei🇨🇳 · Yu-Guo Xu🇨🇳 · Mao-Zhi Yang🇨🇳

   Within the QCD light-cone sum rule (LCSR) approach, we investigate the transition form factors of $D\to a_0(980)$ up to the twist-3 light-cone distribution amplitudes (LCDAs) of the scalar meson $a_0(980)$ in the two-quark picture. Using these form factors, we calculate the differential decay widths and branching ratios of the $D\to a_0(980)e^{+}{\nu }_e$ semileptonic decays. We obtain $\mathcal{B}(D^0\to a_0^{-}(980)e^{+}{\nu }_e)=(4.08_{-1.22}^{+1.37})\times 10^{-4}$ and $\mathcal{B}(D^{+}\to a_0^0(980)e^{+}{\nu }_e)=(5.40_{-1.59}^{+1.78})\times 10^{-4}$. The results are sensitive to the $a_0(980)$ inner structure. These decays can be searched for at BESIII experiment, and any experimental observations will be useful to identify internal quark contents of the $a_0(980)$ meson, which will shed light on understanding theoretical models.

   hep-phPRD(2017)·28 citations
8. 08*

   CP Violation at the Finite Temperature

   Wei Chao🇨🇳

   In this letter we explore the spontaneous CP violation at the finite temperature. We show that the CP-violating phase $\phi$ may only emerge around the time of the electroweak phase transition, and it can provide a scource for generating the matter-antimatter asymmetry of the universe via the electroweak baryogenesis mechanism (EWBG) if the domain wall relating to $\pm \phi$ vacuums is collapsed by a small explicit $Z_2$-breaking term. No extra CP violation is needed! The spontaneous CP is restored after the electroweak phase transition, such that there is no constraint from the electric dipole moment (EDM) measurements. This scenario resolves the tension between the non-observation of EDMs in precision measurement experiments and the requirement of a large CP violation by the EWBG.

   hep-phPLB(2019)·24 citations
9. 09*

   The production of the $f_1(1285)\gamma$ and $a_1(1260)\gamma$ in colliding $e^{+}{e}^{-}$-beams in threshold domain

   M. K. Volkov🇷🇺 · A. A. Pivovarov🇷🇺 · A. A. Osipov🇷🇺

   The processes $e^{+}{e}^{-}\to (f_1(1285),a_1(1260))\gamma$ in threshold domain are considered in the framework of the extended Nambu--Jona-Lasinio model. The channels with the ground $\rho (770)$, $\omega (782)$ and radially excited $\rho (1450)$, $\omega (1420)$ intermediate meson states are taken into account. It is shown that in the process $e^{+}{e}^{-}\to f_1(1285)\gamma$, the probability of the subprocesses with $\rho$-mesons significantly exceeds the probability of the subprocesses with $\omega$-mesons, whereas, in the process $e^{+}{e}^{-}\to a_1(1260)\gamma$, $\rho$- and $\omega$-channels give approximately equal contributions. The mechanism of this effect is discussed. The radiative decay widths of $\rho (1450)\to f_1(1285)\gamma$, $\omega (1420)\to f_1(1285)\gamma$, $\rho (1450)\to a_1(1260)\gamma$ and $\omega (1420)\to a_1(1260)\gamma$ are calculated.

   hep-phInt.J.Mod.Phys.A(2017)·3 citations
10. 10*

    A low scale left-right symmetric mirror model

    Gauhar Abbas🇮🇳

    A left-right symmetric mirror model restoring parity at a high scale in a way such that the mirror fermions and mirror gauge sector simultaneously could exist at TeV scale is discussed. We also provide an ultraviolet completion of the model with vector-like fermions, and discuss some theoretical and phenomenological implications of this model.

    hep-phMod.Phys.Lett.A(2019)·16 citations
11. 11*

    Radiative nonrecoil nuclear finite size corrections of order $\alpha (Z\alpha {)}^5$ to the Lamb shift in light muonic atoms

    R.N. Faustov🇷🇺 · A.P. Martynenko🇷🇺 · F.A. Martynenko🇷🇺 · V.V. Sorokin🇷🇺

    On the basis of quasipotential method in quantum electrodynamics we calculate nuclear finite size radiative corrections of order $\alpha (Z\alpha {)}^5$ to the Lamb shift in muonic hydrogen and helium. To construct the interaction potential of particles, which gives the necessary contributions to the energy spectrum, we use the method of projection operators to states with a definite spin. Separate analytic expressions for the contributions of the muon self-energy, the muon vertex operator and the amplitude with spanning photon are obtained. We present also numerical results for these contributions using modern experimental data on the electromagnetic form factors of light nuclei.

    hep-phphysics.atom-phPLB(2017)·13 citations
12. 12*

    Point-Particle Effective Field Theory III: Relativistic Fermions and the Dirac Equation

    C.P. Burgess🇨🇦 · Peter Hayman🇨🇦 · Markus Rummel🇨🇦 · Laszlo Zalavari🇨🇦

    We formulate point-particle effective field theory (PPEFT) for relativistic spin-half fermions interacting with a massive, charged finite-sized source using a first-quantized effective field theory for the heavy compact object and a second-quantized language for the lighter fermion with which it interacts. This description shows how to determine the near-source boundary condition for the Dirac field in terms of the relevant physical properties of the source, and reduces to the standard choices in the limit of a point source. Using a first-quantized effective description is appropriate when the compact object is sufficiently heavy, and is simpler than (though equivalent to) the effective theory that treats the compact source in a second-quantized way. As an application we use the PPEFT to parameterize the leading energy shift for the bound energy levels due to finite-sized source effects in a model-independent way, allowing these effects to be fit in precision measurements. Besides capturing finite-source-size effects, the PPEFT treatment also efficiently captures how other short-distance source interactions can shift bound-state energy levels, such as due to vacuum polarization (through the Uehling potential) or strong interactions for Coulomb bound states of hadrons, or any hypothetical new short-range forces sourced by nuclei.

    hep-phhep-thnucl-thJHEP(2017)·16 citations
13. 13*

    Effective Higgs Theories in Supersymmetric Grand Unification

    Sibo Zheng🇨🇳

    The effective Higgs theories at the TeV scale in supersymmetric $SU(5)$ grand unification models are systematically derived. Restricted to extensions on $5_H$ containing the Higgs sector we show that only two types of real (vector-like) models and one type of chiral model are found to be consistent with perturbative grand unification. While the chiral model has been excluded by the LHC data, the fate of perturbative unification will be uniquely determined by the two classes of vector-like models.

    hep-phEPJC(2017)·8 citations
14. 14*

    From neutrino electromagnetic interactions to spin oscillations in transversal matter currents

    Alexander Studenikin🇷🇺

    Massive neutrinos have nonzero magnetic moments. It is known that the neutrino spin oscillations can be induced by the neutrino magnetic moment interaction with the transversal magnetic field. We perform a regions derivation of the effective neutrino evolution Hamiltonian in moving matter and show that spin oscillations can be engendered by the interaction with the transversal current of matter. The obtained general expression for the neutrino effective evolution Hamiltonian can be used for investigations of various types of neutrino spin oscillations in the transversal matter currents considered in the neutrino mass and flavour basis.

    hep-phPoS(2017)·12 citations
15. 15*

    Boosting (In)direct Detection of Dark Matter

    Lina Necib🇺🇸

    In this thesis, I study the expected direct and indirect detection signals of dark matter. More precisely, I study three aspects of dark matter; I use hydrodynamic simulations to extract properties of weakly interacting dark matter that are relevant for both direct and indirect detection signals, and construct viable dark matter models with interesting experimental signatures. First, I analyze the full scale Illustris simulation, and find that Galactic indirect detection signals are expected to be largely symmetric, while extragalactic signals are not, due to recent mergers and the presence of substructure. Second, through the study of the high resolution Milky Way simulation Eris, I find that metal-poor halo stars can be used as tracers for the dark matter velocity distribution. I use the Sloan Digital Sky Survey to obtain the first empirical velocity distribution of dark matter, which weakens the expected direct detection limits by up to an order of magnitude at masses $\lesssim 10$ GeV. Finally, I expand the weakly interacting dark matter paradigm by proposing a new dark matter model called boosted dark matter. This novel scenario contains a relativistic component with interesting hybrid direct and indirect detection signatures at neutrino experiments. I propose two search strategies for boosted dark matter, at Cherenkov-based experiments and future liquid-argon neutrino detectors.

    hep-phastro-ph.GA0 citations
16. 16*

    Decay $D\to K^{(\ast )}{\ell }^{+}{\nu }_{\ell }$ in covariant quark model

    N. R. Soni🇮🇳 · J. N. Pandya🇮🇳

    We study the leptonic and semileptonic $D$-meson decays ($D\to {\ell }^{+}{\nu }_{\ell }$ and $D\to K^{(\ast )}{\ell }^{+}{\nu }_{\ell }$) in the framework of covariant quark model with built-in infrared confinement. We compute the required form factors in the entire kinematical momentum transfer region. The calculated form factors are used to evaluate the branching fractions of these transitions. We determine the following ratios of the partial widths: $\Gamma (D^0\to K^{-}{e}^{+}{\nu }_e)/\Gamma (D^{+}\to {\overline{K}}^0{e}^{+}{\nu }_e)=1.02$, $\Gamma (D^0\to K^{-}{\mu }^{+}{\nu }_{\mu })/\Gamma (D^{+}\to {\overline{K}}^0{\mu }^{+}{\nu }_{\mu })=0.99$ and $\Gamma (D^{+}\to {\overline{K}}^0{\mu }^{+}{\nu }_{\mu })/\Gamma (D^{+}\to {\overline{K}}^0{e}^{+}{\nu }_e)=0.97$ which are in close resemblance with the iso-spin invariance and experimental results.

    hep-phPRD(2017)·37 citations
17. 17*

    Treating $Z_c(3900)$ and $Z(4430)$ as the ground-state and first radially excited tetraquarks

    S. S. Agaev🇦🇿 · K. Azizi🇹🇷 · H. Sundu🇹🇷

    Exploration of the resonances $Z_c(3900)$ and $Z(4430)$ are performed by assuming that they are ground-state and first radial excitation of the same tetraquark with $J^P=1^{+}$. The mass and current coupling of the $Z_c(3900)$ and $Z(4430)$ states are calculated using QCD two-point sum rule method by taking into account vacuum condensates up to eight dimensions. We investigate the vertices $Z_c{M}_h{M}_l$ and $Z{M}_h{M}_l$, with $M_h$ and $M_l$ being the heavy and light mesons, and evaluate the strong couplings $g_{Z_c{M}_h{M}_l}$ and $g_{Z{M}_h{M}_l}$ using QCD sum rule on the light cone. The extracted couplings allow us to find the partial width of the decays $Z_c(3900)\to J/\psi \pi ;{\psi }^{\prime }\pi ;{\eta }_c\rho$ and $Z(4430)\to {\psi }^{\prime }\pi ;J/\psi \pi ;{\eta }_c^{\prime }\rho ;{\eta }_c\rho$, which may help in comprehensive investigation of these resonances. We compare width of the decays of $Z_c(3900)$ and $Z(4430)$ resonances with available experimental data as well as existing theoretical predictions.

    hep-phhep-exhep-latPRD(2017)·67 citations
18. 18*

    High energy neutrinos from the Sun

    M. Masip🇪🇸

    The Sun is a main source of high energy neutrinos. These neutrinos appear as secondary particles after the Sun absorbs high-energy cosmic rays, that find there a low-density environment (much thinner than our atmosphere) where most secondary pions, kaons and muons can decay before they lose energy. The main uncertainty in a calculation of the solar neutrino flux is due to the effects of the magnetic fields on the absorption rate of charged cosmic rays. We use recent data from HAWC on the cosmic-ray shadow of the Sun to estimate this rate. We evaluate the solar neutrino flux and show that at 1 TeV it is over ten times larger than the atmospheric one at zenith theta_z=30^o/150^o. The flux that we obtain has a distinct spectrum and flavor composition, and it could be detected in current and upcoming neutrino telescopes. KM3NeT, in particular, looks very promising: it will see the Sun high in the sky (the atmospheric background is lower there than near the horizon) and expects a very good angular resolution (the Sun's radius is just 0.27^o).

    hep-phastro-ph.HEAstropart.Phys.(2018)·29 citations
19. 19*

    Naturalness and Dark Matter Properties of the BLSSM

    Luigi Delle Rose🇬🇧 · Shaaban Khalil🇪🇬 · Simon J.D. King🇬🇧 · Carlo Marzo🇪🇪 · Stefano Moretti🇬🇧 · Cem S. Un🇹🇷

    In this report, we compare the naturalness and Dark Matter (DM) properties of the Minimal Supersymmetric Standard Model (MSSM) and the $B-L$ Supersymmetric Standard Model (BLSSM), with universality in both cases. We do this by adopting standard measures for the quantitative analysis of the Fine-Tuning (FT), at both low (i.e. supersymmetric (SUSY)) and high (i.e. unification) scales. We will see a similar level of FT for both models in these scenarios, with a slightly better FT for the BLSSM at SUSY scales and MSSM at Grand Unification Theory (GUT) scales. When including DM relic constraints, we drastically confine the MSSM's parameter space, whereas we still find a large parameter space available for the non-minimal scenario.

    hep-phPoS(2018)·7 citations
20. 20*

    Gauged Lepton Symmetry Model

    Takaaki Nomura🇰🇷 · Hiroshi Okada🇹🇼

    We study a model with $U(1)$ gauged lepton number symmetry in which the active neutrino masses are generated at two-loop level through the spontaneous breaking of the lepton number symmetry. To cancel gauge anomalies some exotic leptons are introduced that also play an important role in generating neutrino masses and the lightest neutral one can be a dark matter candidate. We discuss a phenomenology of the neutral fermion sector including dark matter, lepton flavor violations, and an extra neutral gauge boson $Z^{\prime }$ that can be tested by $e^{+}{e}^{-}$ collision at the International Linear Collider (ILC).

    hep-ph3 citations
21. 21*

    Narrow pentaquarks as diquark-diquark-antiquark systems

    V.V. Anisovich🇷🇺 · M.A. Matveev🇷🇺 · J. Nyiri🇭🇺 · A.N. Semenova🇷🇺

    The diquark-diquark-antiquark model describes pentaquark states both in terms of quarks and hadrons. The latest LHCb data for pentaquarks with open charm emphasize the importance of hadron components in the structure of pentaquarks. We discuss pentaquark states with hidden charm $P(\bar{c}cuud)$ and those with open charm $P(\bar{u}ussc)$ which were discovered recently in LHCb data ($J/\Psi p$ and ${\Xi }_c^{+}{K}^{-}$ spectra correspondingly). Considering the observed states as members of the lowest (s-wave) multiplet we discuss the mass splitting of states and the dumping of their widths.

    hep-phMod.Phys.Lett.A(2017)·21 citations
22. 22*

    Rare ${\Lambda }_b\to n{l}^{+}{l}^{-}$ decays in the relativistic quark-diquark picture

    R. N. Faustov🇷🇺 · V. O. Galkin🇷🇺

    The form factors of the rare ${\Lambda }_b\to n{l}^{+}{l}^{-}$ decays are calculated in the framework of the relativistic quark-diquark picture of baryons with the consistent account of the relativistic effects. Their momentum transfer squared dependence is determined explicitly in the whole accessible kinematical range. The decay branching fractions, forward-backward asymmetries and the fractions of longitudinally polarized dileptons are determined. The branching fraction of the rare ${\Lambda }_b\to n{\mu }^{+}{\mu }^{-}$ decay are found to be $\mathrm{Br}({\Lambda }_b\to n{\mu }^{+}{\mu }^{-})=(3.75\pm 0.38)\times 10^{-8}$ and thus could be measured at the LHC. Prediction for the branching fraction of the rare radiative ${\Lambda }_b\to n\gamma$ decay is also given.

    hep-phhep-exMod.Phys.Lett.A(2017)·12 citations
23. 23*

    $k_T$-factorization approach to the Higgs boson production in $Z{Z}^{\ast }\to 4\ell$ channel at the LHC

    Rashidul Islam🇮🇳 · Mukesh Kumar🇿🇦 · Vaibhav S. Rawoot🇮🇳

    We calculated a differential cross section of the Higgs boson production in the $h\to Z{Z}^{\ast }\to 4\ell$ decay channel within the framework of $k_T$-factorization. Results are obtained using an off-shell matrix element for the $g^{\ast }{g}^{\ast }\to h\to Z{Z}^{\ast }\to 4\ell$ process together with Ciafaloni-Catani-Fiorani-Marchesini (CCFM) evolution equations for an unintegrated gluon distribution function. We have presented a comparison of our results with the latest experimental measurements at $\sqrt{S}$ = 8 TeV and $\sqrt{S}$ = 13 TeV from the ATLAS and CMS collaborations at the LHC. In addition to this, we have compared our results with the results from the collinear factorization formalism calculated up to next-to-next-to-leading order plus next-to-next-to-leading logarithm (NNLO + NNLL) accuracy obtained using the HRes code for the Higgs boson production in the gluon-gluon fusion process. Our estimates are consistently close to NNLO + NNLL results obtained using a collinear factorization formalism and are also in agreement with experimental measurements.

    hep-phEPJC(2019)·7 citations
24. 24*

    Effect of sea quarks on single-spin asymmetries $A_N^{W^{\pm }}$ in transversely polarized pp collisions at RHIC

    Fang Tian🇨🇳 · Chang Gong🇨🇳 · Bo-Qiang Ma🇨🇳

    We calculate the single-spin asymmetries $A_N^{W^{\pm }}$ of $W^{\pm }$ bosons produced in transversely polarized pp collisions with the valence part of the up (u) and down (d) quark Sivers functions treated by an available parametrization and the light-cone quark spectator-diquark model respectively, while the sea part Sivers functions of u and d quarks treated as parametrization. Comparing our results with those from experimental data at RHIC, we find that the Sivers functions of sea quarks play an important role in the determination of the shapes of $A_N^{W^{\pm }}$. It is shown that $A_N^{W^{-}}$ is sensitive to u sea Sivers function, while $A_N^{W^{+}}$ to d sea Sivers function intuitively. The results show that the contributions of u and d sea Sivers functions are rather sizable and of the same sign, and their signs agree with that of d valence quarks and are opposite to that of u valence quarks.

    hep-phNPA(2017)·3 citations
25. 25*

    Higher-twist corrections to gluon TMD factorization

    I. Balitsky🇺🇸 · A. Tarasov🇺🇸

    We calculate power corrections to TMD factorization for particle production by gluon-gluon fusion in hadron-hadron collisions.

    hep-phJHEP(2017)·63 citations
26. 26*

    Phenomenology of flavorful composite vector bosons in light of $B$ anomalies

    Shinya Matsuzaki🇯🇵 · Kenji Nishiwaki🇰🇷 · Ryoutaro Watanabe🇨🇦

    We analyze the flavor structure of composite vector bosons arising in a model of vectorlike technicolor, often called hypercolor (HC), with eight flavors that form a one-family content of HC fermions. Dynamics of the composite vector bosons, referred to as HC rho in this paper, are formulated together with HC pions by the hidden local symmetry (HLS), in a way analogous to QCD vector mesons. Then coupling properties to the standard model (SM) fermions, which respect the HLS gauge symmetry, are described in a way that couplings of the HC rhos to the left-handed SM quarks and leptons are given by a well-defined setup as taking the flavor mixing structures into account. Under the present scenario, we discuss significant bounds on the model from electroweak precision tests, flavor physics, and collider physics. We also try to address B anomalies in processes such as B -> K(*) mu+ mu- and B -> D(*) tau nu, recently reported by LHCb, Belle, (ATLAS, and CMS in part.) Then we find that the present model can account for the anomaly in B -> K(*) mu+ mu- consistently with the other constraints while it predicts no significant deviations in B -> D(*) tau nu from the SM, which can be examined in the future Belle II experiment. The former is archived with the form C9 = -C10 of the Wilson coefficients for effective operators of b -> s mu+ mu-, which has been favored by the recent experimental data. We also investigate current and future experimental limits at the Large Hadron Collider (LHC) and see that possible collider signals come from dijet and ditau, or dimuon resonant searches for the present scenario with TeV mass range. To conclude, the present b -> s mu+ mu- anomaly is likely to imply discovery of new vector bosons in the ditau or dimuon channel in the context of the HC rho model. Our model can be considered as a UV completion of conventional U(1)' model.

    hep-phhep-exJHEP(2017)·32 citations
27. 27*

    Extracting the sigma-term from low-energy pion-nucleon scattering

    Jacobo Ruiz de Elvira🇨🇭 · Martin Hoferichter🇺🇸 · Bastian Kubis🇩🇪 · Ulf-G. Meißner🇩🇪

    We present an extraction of the pion-nucleon ($\pi N$) scattering lengths from low-energy $\pi N$ scattering, by fitting a representation based on Roy-Steiner equations to the low-energy data base. We show that the resulting values confirm the scattering-length determination from pionic atoms, and discuss the stability of the fit results regarding electromagnetic corrections and experimental normalization uncertainties in detail. Our results provide further evidence for a large $\pi N$ $\sigma$-term, ${\sigma }_{\pi N}=58(5)$ MeV, in agreement with, albeit less precise than, the determination from pionic atoms.

    hep-phhep-latnucl-exnucl-thJ.Phys.G(2018)·138 citations
28. 28*

    The peculiar GRB 110731A: Lorentz factor, jet composition, central engine, and progenitor

    HouJun Lü🇨🇳 · XiangGao Wang🇨🇳 · RuiJing Lu🇨🇳 · Lin Lan🇨🇳 · He Gao🇨🇳 · EnWei Liang🇨🇳 · Melissa L. Graham🇺🇸 · WeiKang Zheng🇺🇸 · Alexei V. Filippenko🇺🇸 · Bing Zhang🇺🇸

    The jet compositions, central engines, and progenitors of gamma-ray bursts (GRBs) remain open questions in GRB physics. Applying broadband observations, including GRB prompt emission and afterglow properties derived from {\em Fermi} and {\em Swift} data, as well as from Keck host-galaxy observations, we address these questions for the peculiar, bright GRB 110731A. By using the pair-opacity method, we derive ${\Gamma }_0>190$ during the prompt emission phase. Alternatively, we derive ${\Gamma }_0\approx 580$ and ${\Gamma }_0\approx 154$ by invoking the early-afterglow phase within the homogeneous density and wind cases, respectively. On the other hand, nondetection of a thermal component in the spectra suggests that the prompt emission is likely powered by dissipation of a Poynting-flux-dominated jet leading to synchrotron radiation in an optically thin region. The nondetection of a jet break in the X-ray and optical bands allows us to place a lower limit on the jet opening angle ${\theta }_{\mathrm{j}}>5.5^{\circ }$. Within a millisecond magnetar central engine scenario, we derive the period $P_0$ and polar magnetic field strength $B_{\mathrm{p}}$, which have extreme (but still allowed) values. The moderately short observed duration (7.3\,s) and relatively large redshift ($z=2.83$) places the burst as a "rest-frame short" GRB, so the progenitor of the burst is subject to debate. Its relatively large $f_{\mathrm{eff},z}$ parameter (ratio of the 1\,s peak flux of a pseudo-GRB and the background flux) and a large physical offset from a potential host galaxy suggest that the progenitor of GRB 110731A may be a compact-star merger.

    ↳ astro-ph.HEhep-phApJ(2017)·14 citations
29. 29*

    Compact Chern-Simons vortices

    D. Bazeia🇧🇷 · L. Losano🇧🇷 · M.A. Marques🇧🇷 · R. Menezes🇧🇷

    We introduce and investigate new models of the Chern-Simons type in the three-dimensional spacetime, focusing on the existence of compact vortices. The models are controlled by potentials driven by a single real parameter that can be used to change the profile of the vortex solutions as they approach their boundary values. One of the models unveils an interesting new behavior, the tendency to make the vortex compact, as the parameter increases to larger and larger values. We also investigate the behavior of the energy density and calculate the total energy numerically.

    ↳ hep-thhep-phPLB(2017)·17 citations
30. 30*

    Lorentz-covariant coordinate-space representation of the leading hadronic contribution to the anomalous magnetic moment of the muon

    Harvey B. Meyer🇩🇪

    We present a Lorentz-covariant, Euclidean coordinate-space expression for the hadronic vacuum polarisation, the Adler function and the leading hadronic contribution to the anomalous magnetic moment of the muon. The representation offers a lot of flexibility for an implementation in lattice QCD. We expect it to be particularly helpful for the quark-line disconnected contributions.

    ↳ hep-lathep-phEPJC(2017)·32 citations
31. 31*

    Quantum Kinetic Theory of the Chiral Anomaly

    Akihiko Sekine🇺🇸 · Dimitrie Culcer🇦🇺 · Allan H. MacDonald🇺🇸

    We present a general quantum kinetic theory of low-field magnetotransport in weakly disordered crystals that accounts fully for the interplay between electric-field induced interband coherence, Bloch-state scattering, and an external magnetic field. The quantum kinetic equation we derive for the Bloch-state density matrix naturally incorporates the momentum-space Berry phase effects whose influence on Bloch-state wavepacket dynamics is normally incorporated into transport theory in an ad hoc manner. The Berry phase correction to the momentum-space density of states in the presence of an external magnetic field implied by semiclassical wavepacket dynamics is captured by our theory as an intrinsic density-matrix response to a magnetic field. We propose a simple and general procedure for expanding the linear response of the Bloch-state density matrix to an electric field in powers of magnetic field. As an illustration, we apply our theory to magnetotransport in Weyl semimetals. We show that the chiral anomaly (positive magnetoconductivity quadratic in magnetic field) that appears when separate Fermi surface pockets surround distinct Weyl points survives only when intervalley scattering is very weak compared to intravalley scattering.

    ↳ cond-mat.mes-hallcond-mat.mtrl-scicond-mat.str-elhep-lat+1PRB(2017)·27 citations
32. 32*

    Masses and decay constants of the $D_{s0}^{\ast }(2317)$ and $D_{s1}(2460)$ from $N_f=2$ lattice QCD close to the physical point

    Gunnar S. Bali🇩🇪 · Sara Collins🇩🇪 · Antonio Cox🇩🇪 · Andreas Schäfer🇩🇪

    We perform a high statistics study of the $J^P=0^{+}$ and $1^{+}$ charmed-strange mesons, $D_{s0}^{\ast }(2317)$ and $D_{s1}(2460)$, respectively. The effects of the nearby $DK$ and $D^{\ast }K$ thresholds are taken into account by employing the corresponding four quark operators. Six ensembles with $N_f=2$ non-perturbatively $\mathcal{O}(a)$ improved clover Wilson sea quarks at $a=0.07$ fm are employed, covering different spatial volumes and pion masses: linear lattice extents $L/a=24,32,40,64$, equivalent to 1.7 fm to 4.5 fm, are realised for $m_{\pi }=290$ MeV and $L/a=48,64$ or 3.4 fm and 4.5 fm for an almost physical pion mass of $150$ MeV. Through a phase shift analysis and the effective range approximation we determine the scattering lengths, couplings to the thresholds and the infinite volume masses. Differences relative to the experimental values are observed for these masses, however, this is likely to be due to discretisation effects as spin-averaged quantities and splittings are reasonably compatible with experiment. We also compute the weak decay constants of the scalar and axialvector and find $f_V^{0^{+}}=114(2)(0)(+5)(10)$ MeV and $f_A^{1^{+}}=194(3)(4)(+5)(10)$ MeV, where the errors are due to statistics, renormalisation, finite volume and lattice spacing effects.

    ↳ hep-lathep-phPRD(2017)·142 citations
33. 33*

    Confining potential of Y-string on the lattice at finite T

    Ahmed S. Bakry🇨🇳 · Xurong Chen🇨🇳 · Peng-Ming Zhang🇨🇳

    The potential due to a system of three static quark (3Q) is studied using SU(3) lattice QCD at finite temperature with Polyakov loops operators. We focused our analysis on the large distance properties of the 3Q potential and found a good fit behavior to the Y-string model formula. In addition to the linearly confining term proportional to the minimal length of the Y-string, we observed that the subleading logarithmic term, which is proportional to Dedekind eta function and accounts for the Y-string's quantum fluctuations, is necessary to reproduce the quark anti-quark string tension of the corresponding mesonic system at finite temperature.

    ↳ hep-lathep-phEPJ Web Conf.(2016)·8 citations
34. 34*

    Extended Gauge Theory, Bi-Spinors, and Scalar Supersymmetry

    Alex Jourjine🇩🇪

    Within the context of the extended bi-spinor gauge theory we describe a new off-shell realization of scalar supersymmetry (s-susy) of massless interacting fields with U(1), U(1) x SU(N) and U(1) x SU(N_1) x SU(N_2) gauge groups. S-susy acts in the space of graded differential forms. The realization is non-linear in the non-abelian case. S-susy would not require the doubling of the SM particle spectrum. Instead, essentially only the forth generation of quarks and leptons would be needed as extra field content. The theory is by construction globally U(2,2) invariant and is an example of a supersymmetric CFT.

    ↳ hep-thhep-ph0 citations
35. 35*

    Dark Matter Limits From Dwarf Spheroidal Galaxies with The HAWC Gamma-Ray Observatory

    A. Albert · R. Alfaro · C. Alvarez · J.D. Álvarez · R. Arceo · J.C. Arteaga-Velázquez · D. Avila Rojas · H.A. Ayala Solares · N. Bautista-Elivar · A. Becerril · E. Belmont-Moreno · S.Y. BenZvi and 69 other authors

    The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a wide field of view observatory sensitive to 500 GeV - 100 TeV gamma rays and cosmic rays. It can also perform diverse indirect searches for dark matter (DM) annihilation and decay. Among the most promising targets for the indirect detection of dark matter are dwarf spheroidal galaxies. These objects are expected to have few astrophysical sources of gamma rays but high dark matter content, making them ideal candidates for an indirect dark matter detection with gamma rays. Here we present individual limits on the annihilation cross section and decay lifetime for 15 dwarf spheroidal galaxies within the HAWC field-of-view, as well as their combined limit. These are the first limits on the annihilation cross section and decay lifetime using data collected with HAWC.

    ↳ astro-ph.HEhep-phApJ(2018)·154 citations
36. 36*

    Parton Distribution Function with Non-perturbative Renormalization from Lattice QCD

    Jiunn-Wei Chen🇹🇼 · Tomomi Ishikawa🇨🇳 · Luchang Jin🇺🇸 · Huey-Wen Lin🇺🇸 · Yi-Bo Yang🇺🇸 · Jian-Hui Zhang🇩🇪 · Yong Zhao🇺🇸

    We present lattice results for the isovector unpolarized parton distribution with nonperturbative RI/MOM-scheme renormalization on the lattice. In the framework of large-momentum effective field theory (LaMET), the full Bjorken-$x$ dependence of a momentum-dependent quasi-distribution is calculated on the lattice and matched to the ordinary lightcone parton distribution at one-loop order, with power corrections included. The important step of RI/MOM renormalization that connects the lattice and continuum matrix elements is detailed in this paper. A few consequences of the results are also addressed here.

    ↳ hep-lathep-phnucl-thPRD(2018)·177 citations
37. 37*

    Iterated Elliptic and Hypergeometric Integrals for Feynman Diagrams

    J. Ablinger🇦🇹 · J. Blümlein🇩🇪 · A. De Freitas🇩🇪 · M. van Hoeij🇺🇸 · E. Imamoglu🇺🇸 · C.G. Raab🇦🇹 · C.-S. Radu🇦🇹 · C. Schneider🇦🇹

    We calculate 3-loop master integrals for heavy quark correlators and the 3-loop QCD corrections to the $\rho$-parameter. They obey non-factorizing differential equations of second order with more than three singularities, which cannot be factorized in Mellin-$N$ space either. The solution of the homogeneous equations is possible in terms of convergent close integer power series as ${}_2{F}_1$ Gauß{} hypergeometric functions at rational argument. In some cases, integrals of this type can be mapped to complete elliptic integrals at rational argument. This class of functions appears to be the next one arising in the calculation of more complicated Feynman integrals following the harmonic polylogarithms, generalized polylogarithms, cyclotomic harmonic polylogarithms, square-root valued iterated integrals, and combinations thereof, which appear in simpler cases. The inhomogeneous solution of the corresponding differential equations can be given in terms of iterative integrals, where the new innermost letter itself is not an iterative integral. A new class of iterative integrals is introduced containing letters in which (multiple) definite integrals appear as factors. For the elliptic case, we also derive the solution in terms of integrals over modular functions and also modular forms, using $q$-product and series representations implied by Jacobi's ${\vartheta }_i$ functions and Dedekind's $\eta$-function. The corresponding representations can be traced back to polynomials out of Lambert--Eisenstein series, having representations also as elliptic polylogarithms, a $q$-factorial $1/{\eta }^k(\tau )$, logarithms and polylogarithms of $q$ and their $q$-integrals. Due to the specific form of the physical variable $x(q)$ for different processes, different representations do usually appear. Numerical results are also presented.

    ↳ hep-thcs.SChep-phmath-ph+2J.Math.Phys.(2018)·154 citations
38. 38*

    On the Catalysis of the Electroweak Vacuum Decay by Black Holes at High Temperature

    D. Canko🇬🇷 · I. Gialamas🇬🇷 · G. Jelic-Cizmek🇨🇭 · A. Riotto🇨🇭 · N. Tetradis🇬🇷

    We study the effect of primordial black holes on the classical rate of nucleation of AdS regions within the standard electroweak vacuum at high temperature. We find that the energy barrier for transitions to the new vacuum, which determines the exponential suppression of the nucleation rate, can be reduced significantly, or even eliminated completely, in the black-hole background if the Standard Model Higgs is coupled to gravity through the renormalizable term $\xi \mathcal{R}{h}^2$.

    ↳ hep-thastro-ph.COhep-phEPJC(2018)·55 citations
39. 39*

    Ipanema-\beta : tools and examples for HEP analysis on GPU

    D. Martínez Santos🇪🇸 · P. Álvarez Cartelle🇬🇧 · M. Borsato🇪🇸 · V. G. Chobanova🇪🇸 · J. García Pardiñas🇪🇸 · M. Lucio Martínez🇪🇸 · M. Ramos Pernas🇪🇸

    We present here a set of examples, classes and tools which can be used for statistical analysis in Graphics Processing Units (GPU). This includes binned and unbinned maximum likelihood fits, pseudo-experiment generation, convolutions, Markov Chain Monte Carlo method implementations, and limit setting techniques.

    ↳ hep-exhep-phphysics.data-an11 citations
40. 40*

    Quantum gravity effects on Hawking radiation of Schwarzschild-de Sitter black holes

    T. Ibungochouba Singh🇮🇳 · I. Ablu Meitei🇮🇳 · K. Yugindro Singh🇮🇳

    The correction of Hawking temperature of Schwarzschild-de Sitter (SdS) black hole is investigated using the generalized Klein-Gordon equation and the generalized Dirac equation by taking the quantum gravity effects into account. We derive the corrected Hawking temperatures for scalar particles and fermions crossing the event horizon. The quantum gravity effects prevent the rise of temperature in the SdS black hole. Besides correction of Hawking temperature, the Hawking radiation of SdS black hole is also investigated using massive particles tunneling method. By considering self gravitation effect of the emitted particles and the space time background to be dynamical, it is also shown that the tunneling rate is related to the change of Bekenstein-Hawking entropy and small correction term $(1+2\beta m^2)$. If the energy and the angular momentum are taken to be conserved, the derived emission spectrum deviates from the pure thermal spectrum. This result gives a correction to the Hawking radiation and is also in agreement with the result of Parikh and Wilczek.

    ↳ gr-qchep-phhep-thInt.J.Theor.Phys.(2017)·18 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.