Fri·Apr 28, 2017Friday·April 28, 2017

1. 01*

   Unity of pomerons from gauge/string duality

   Alfonso Ballon-Bayona🇧🇷 · Robert Carcasses Quevedo🇵🇹 · Miguel S. Costa🇵🇹

   We develop a formalism where the hard and soft pomeron contributions to high energy scattering arise as leading Regge poles of a single kernel in holographic QCD. The kernel is obtained using effective field theory inspired by Regge theory of a 5-d string theory. It describes the exchange of higher spin fields in the graviton Regge trajectory that are dual to glueball states of twist two. For a specific holographic QCD model we describe Deep Inelastic Scattering in the Regge limit of low Bjorken x, finding good agreement with experimental data from HERA. The observed rise of the effective pomeron intercept, as the size of the probe decreases, is reproduced by considering the first four pomeron trajectories. In the case of soft probes, relevant to total cross sections, the leading hard pomeron trajectory is suppressed, such that in this kinematical region we reproduce an intercept of 1.09 compatible with the QCD soft pomeron data. In the spectral region of positive Maldelstam variable t the first two pomeron trajectories are consistent with current expectations for the glueball spectrum from lattice simulations.

   hep-phhep-thJHEP(2017)·24 citations
2. 02*

   Creating the Baryon Asymmetry from Lepto-Bubbles

   Silvia Pascoli🇬🇧 · Jessica Turner🇬🇧 · Ye-Ling Zhou🇬🇧

   We propose a new mechanism of baryogenesis which proceeds via a CP-violating phase transition. During this phase transition, the coupling of the Weinberg operator is dynamically realised and subsequently a lepton asymmetry is generated via the non-zero interference of this operator at different times. This new scenario of leptogenesis provides a direct connection between the baryon asymmetry, low energy neutrino parameters and leptonic flavour models.

   hep-ph1 citation
3. 03*

   Precision Electroweak Measurements at Run 2 and Beyond

   Jens Erler🇲🇽

   After reviewing the key features of the global electroweak fit, I will provide updated results and offer experimental and theoretical contexts. I will also make the case for greater precision and highlight future directions.

   hep-phhep-ex6 citations
4. 04*

   Linking axionlike dark matter to neutrino masses

   C. D. R. Carvajal🇨🇴 · B. L. Sánchez-Vega🇧🇷 · O. Zapata🇨🇴

   We present a framework linking axionlike particles (ALPs) to neutrino masses through the minimal inverse seesaw (ISS) mechanism in order to explain the dark matter (DM) puzzle. Specifically, we explore three minimal ISS cases where mass scales are generated through gravity-induced operators involving a scalar field hosting ALPs. In all of these cases, we find gravity-stable models providing the observed DM relic density and, simultaneously, consistent with the phenomenology of neutrinos and ALPs. Remarkably, in one of the ISS cases, the DM can be made of ALPs and sterile neutrinos. Furthermore, other considered ISS cases have ALPs with parameters inside regions to be explored by proposed ALPs experiments.

   hep-phPRD(2017)·22 citations
5. 05*

   Describing dynamical fluctuations and genuine correlations by Weibull regularity

   Ranjit K. Nayak🇮🇳 · Sadhana Dash (Indian Inst. Tech., Mumbai)🇮🇳 · Edward K. Sarkisyan-Grinbaum (CERN & Texas U., Arlington)🇨🇭 · Marek Tasevsky (Prague, Inst. Phys.)🇨🇿

   The Weibull parametrization of the multiplicity distribution is used to describe the multidimensional local fluctuations and genuine multiparticle correlations measured by OPAL in the large statistics $e^{+}{e}^{-}\to Z^0\to hadrons$ sample. The data are found to be well reproduced by the Weibull model up to higher orders. The Weibull predictions are compared to the predictions by the two other models, namely by the negative binomial and modified negative binomial distributions which mostly failed to fit the data. The Weibull regularity, which is found to reproduce the multiplicity distributions along with the genuine correlations, looks to be the optimal model to describe the multiparticle production process.

   hep-phhep-ex4 citations
6. 06*

   Dark Energy Density in SUGRA models and degenerate vacua

   C. D. Froggatt🇬🇧 · H. B. Nielsen🇩🇰 · R. Nevzorov🇦🇺 · A. W. Thomas🇦🇺

   In N=1 supergravity the tree-level scalar potential of the hidden sector may have a minimum with broken local supersymmetry (SUSY) as well as a supersymmetric Minkowski vacuum. These vacua can be degenerate, allowing for a consistent implementation of the multiple point principle. The first minimum where SUSY is broken can be identified with the physical phase in which we live. In the second supersymmetric phase, in flat Minkowski space, SUSY may be broken dynamically either in the observable or in the hidden sectors inducing a tiny vacuum energy density. We argue that the exact degeneracy of these phases may shed light on the smallness of the cosmological constant. Other possible phenomenological implications are also discussed. In particular, we point out that the presence of such degenerate vacua may lead to small values of the quartic Higgs coupling and its beta function at the Planck scale in the physical phase.

   hep-phgr-qchep-thInt.J.Mod.Phys.A(2017)·4 citations
7. 07*

   Effects of custodial symmetry breaking in the Georgi-Machacek model at high energies

   Simone Blasi🇮🇹 · Stefania De Curtis🇮🇹 · Kei Yagyu🇮🇹

   The model proposed by Georgi and Machacek enables the Higgs sector to involve isospin triplet scalar fields while retaining a custodial $SU(2{)}_V$ symmetry in the potential and thus ensuring the electroweak $\rho$ parameter to be one at tree level. This custodial symmetry, however, is explicitly broken by loop effects of the $U(1{)}_Y$ hypercharge gauge interaction. In order to make the model consistent at high energies, we construct the most general form of the Higgs potential without the custodial symmetry, and then we derive the one-loop $\beta$-functions for all the model parameters. Assuming the ${\delta }_i$ quantities describing the custodial symmetry breaking to be zero at low energy, we find that $|{\delta }_i|$ are typically smaller than the magnitude of the $U(1{)}_Y$ gauge coupling and the other running parameters in the potential also at high energy without spoiling perturbativity and vacuum stability. We also clarify that the mass degeneracy among the $SU(2{)}_V$ 5-plet and 3-plet Higgs bosons is smoothly broken by $\sim 0.1\%$ corrections. These results show that the amount of the custodial symmetry breaking is well kept under control up to energies close to the theory cutoff.

   hep-phPRD(2017)·55 citations
8. 08*

   Measuring the Leptonic Dirac CP Phase with TNT2K

   Shao-Feng Ge🇩🇪

   I describe how the TNT2K (Tokai and Toyama to Kamioka) configuration with a muon decay at rest ($\mu$DAR) add-on to T2(H)K can achieve better measurement of the leptonic Dirac CP phase ${\delta }_D$. It has five-fold advantages of high efficiency, smaller CP uncertainty, absence of degeneracy, as well as guaranteeing CP sensitivity against non-unitary mixing (NUM) and non-standard interaction (NSI). In comparison to the flux upgrade with T2K-II, the detector upgrade with T2HK, and the baseline upgrade with T2HKK, TNT2K is a totally different concept with spectrum upgrade to solve the intrinsic problems in current and next generations of CP measurement experiments. With a single $\mu$DAR source, TNT2K is much cheaper and technically much easier than the DAE$\delta$ALUS proposal. The latter needs three sources that cannot run simultaneously and consequently requires much higher fluxes. The single $\mu$DAR source at TNT2K also allows a single near detector ($\mu$Near) to fully utilize the neutrino flux for the purpose of constraining NUM, but this is impossible at DAE$\delta$ALUS with three spatially separated sources.

   hep-phhep-ex8 citations
9. 09*

   Analyzing the mesonic spectrum using the method of Schottky anomaly

   Aritra Biswas🇮🇳

   A possible diagnostic is proposed which may be used to infer the different scales underlying the dynamical structure of hadronic resonances using the phenomenon of Schottky anomaly.

   hep-phSpringer Proc.Phys.(2018)·0 citations
10. 10*

    Higher-order radiative corrections for $b\bar{b}\to H^{-}{W}^{+}$

    Nikolaos Kidonakis🇺🇸

    I present higher-order radiative corrections from collinear and soft gluon emission for the associated production of a charged Higgs boson with a $W$ boson. The calculation uses expressions from resummation at next-to-leading-logarithm accuracy. From the resummed cross section I derive analytical formulas at approximate NNLO and N${}^3$LO. Total cross sections are presented for the process $b\bar{b}\to H^{-}{W}^{+}$ at various LHC energies. The transverse-momentum and rapidity distributions of the charged Higgs boson are also calculated.

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

    fastNLO tables for NNLO top-quark pair differential distributions

    Michal Czakon🇩🇪 · David Heymes🇬🇧 · Alexander Mitov🇬🇧

    We release fastNLO tables with NNLO QCD top-quark pair differential distributions corresponding to 8 TeV ATLAS [Eur. Phys. J. C 76 538 (2016)] and CMS [Eur. Phys. J. C 75 542 (2015)] measurements. This is the first time fastNLO tables with NNLO QCD accuracy have been made publicly available. The tables are indispensable in pdf fits and allow, for the first time, very fast calculation of differential distributions with any pdf set and for different values of ${\alpha }_s$. The numerical accuracy of the resulting differential distributions is high and comparable to the accuracy of all publicly available NNLO top-quark differential calculations. We intend to keep producing tables corresponding to existing and future LHC measurements at various collider energies.

    hep-phhep-ex94 citations
12. 12*

    Spatial distribution of angular momentum inside the nucleon

    Cédric Lorcé🇫🇷 · Luca Mantovani🇮🇹 · Barbara Pasquini🇮🇹

    We discuss in detail the spatial distribution of angular momentum inside the nucleon. We show that the discrepancies between different definitions originate from terms that integrate to zero. Even though these terms can safely be dropped at the integrated level, they have to be taken into account at the density level. Using the scalar diquark model, we illustrate our results and, for the first time, check explicitly that the equivalence between kinetic and canonical orbital angular momentum persists at the density level, as expected in a system without gauge degrees of freedom.

    hep-phPLB(2018)·109 citations
13. 13*

    Latest developments in the simulation of final states involving top-pair and heavy bosons

    Emanuele Re🇨🇭

    I give an overview of recent progress in the simulation of final states involving top-quarks and vector bosons pair. First I'll discuss the recently found solutions needed to simulate fully differential top pair production ($pp\to b\bar{b}$ + 4 leptons) at NLO+PS accuracy, retaining off-shellness and interference effects exactly. In the second part, I'll review the MiNLO (Multi-scale Improved NLO) method, and then show a recent application, namely the simultaneous NLO+PS description of $W^{+}{W}^{-}$ and $W^{+}{W}^{-}+$ 1 jet production.

    hep-phPoS(2017)·0 citations
14. 14*

    Loop induced type-II seesaw model and GeV dark matter with $U(1{)}_{B-L}$ gauge symmetry

    Takaaki Nomura🇰🇷 · Hiroshi Okada🇹🇼

    We propose a model with $U(1{)}_{B-L}$ gauge symmetry and several new fermions in no conflict with anomaly cancellation where the neutrino masses are given by the vacuum expectation value of Higgs triplet induced at the one-loop level. The new fermions are odd under discrete $Z_2$ symmetry and the lightest one becomes dark matter candidate. We find that the mass of dark matter is typically $O(1)$-$O(10)$ GeV. Then relic density of the dark matter is discussed.

    hep-phPLB(2017)·21 citations
15. 15*

    Real and virtual photons effects in di-lepton production at the LHC

    Elena Accomando🇬🇧 · Juri Fiaschi🇬🇧 · Francesco Hautmann🇬🇧 · Stefano Moretti🇬🇧 · Claire H. Shepherd-Themistocleous🇬🇧

    We show the SM prediction of di-lepton production at the LHC where to the usual Drell-Yan production we add the contribution from Photon-Initiated processes. We discuss the effects of the inclusion of photon interactions in the high invariant mass region (TeV region) and their consequences on BSM heavy Z'-boson searches.

    hep-phNuovo Cim.C(2018)·3 citations
16. 16*

    Mass spectrum and decay constants of radially excited vector mesons

    Fredy F. Mojica🇨🇴 · Carlos E. Vera🇨🇴 · Eduardo Rojas🇨🇴 · Bruno El-Bennich🇧🇷

    We calculate the masses and weak decay constants of flavorless ground and radially excited $J^P=1^{-}$ mesons and the corresponding quantities for the K^*, within a Poincaré covariant continuum framework based on the Bethe-Salpeter equation. We use in both, the quark's gap equation and the meson bound-state equation, an infrared massive and finite interaction in the leading symmetry-preserving truncation. While our numerical results are in rather good agreement with experimental values where they are available, no single parametrization of the QCD inspired interaction reproduces simultaneously the ground and excited mass spectrum, which confirms earlier work on pseudoscalar mesons. This feature being a consequence of the lowest truncation, we pin down the range and strength of the interaction in both cases to identify common qualitative features that may help to tune future interaction models beyond the rainbow-ladder approximation.

    hep-phPRD(2017)·41 citations
17. 17*

    Extricating New Physics Scenarios at DUNE with High Energy Beams

    Mehedi Masud🇮🇳 · Mary Bishai🇺🇸 · Poonam Mehta🇮🇳

    The proposed Deep Underground Neutrino Experiment (DUNE) utilizes a wide-band on-axis tunable muon-(anti)neutrino beam with a baseline of 1300 km to search for CP violation with high precision. Given the long baseline, DUNE is also sensitive to effects due to non-standard neutrino interactions (NSI) which can interfere with the standard 3-flavor oscillation paradigm. In this Letter, we exploit the tunability of the DUNE neutrino beam over a wide-range of energies and utilize a new theoretical metric to devise an experimental strategy for separating oscillation effects due to NSI from the standard 3-flavor oscillation scenario. Using our metric, we obtain an optimal combination of beam tunes and distribution of run times in neutrino and anti-neutrino modes that would enable DUNE to isolate new physics scenarios from the standard. To the best of our knowledge, our strategy is entirely new and has not been reported elsewhere.

    hep-phhep-exSci.Rep.(2019)·39 citations
18. 18*

    A Perturbative RS I Cosmological Phase Transition

    Don Bunk🇺🇸 · Jay Hubisz🇺🇸 · Bithika Jain🇰🇷

    We identify a class of Randall-Sundrum type models with a successful first order cosmological phase transition during which a 5D dual of approximate conformal symmetry is spontaneously broken. Our focus is on soft-wall models that naturally realize a light radion/dilaton and suppressed dynamical contribution to the cosmological constant. We discuss phenomenology of the phase transition after developing a theoretical and numerical analysis of these models both at zero and finite temperature. We demonstrate a model with a TeV-Planck hierarchy and with a successful cosmological phase transition where the UV value of the curvature corresponds, via AdS/CFT, to an $N$ of $20$, where 5D gravity is expected to be firmly in the perturbative regime.

    hep-phastro-ph.COhep-thEPJC(2018)·64 citations
19. 19*

    Classification of compactified $su(N_c)$ gauge theories with fermions in all representations

    Mohamed M. Anber🇺🇸 · Loïc Vincent-Genod🇨🇭

    We classify $su(N_c)$ gauge theories on ${\mathbb{R}}^3\times {\mathbb{S}}^1$ with massless fermions in higher representations obeying periodic boundary conditions along ${\mathbb{S}}^1$. In particular, we single out the class of theories that is asymptotically free and weakly coupled in the infrared, and therefore, is amenable to semi-classical treatment. Our study is conducted by carefully identifying the vacua inside the affine Weyl chamber using Verma bases and Frobenius formula techniques. Theories with fermions in pure representations are generally strongly coupled. The only exceptions are the four-index symmetric representation of $su(2)$ and adjoint representation of $su(N_c)$. However, we find a plethora of admissible theories with fermions in mixed representations. A sub-class of these theories have degenerate perturbative vacua separated by domain walls. In particular, $su(N_c)$ theories with fermions in the mixed representations adjoint$\oplus$fundamental and adjoint$\oplus$two-index symmetric admit degenerate vacua that spontaneously break the parity $\mathcal{P}$, charge conjugation $\mathcal{C}$, and time reversal $\mathcal{T}$ symmetries. These are the first examples of strictly weakly coupled gauge theories on ${\mathbb{R}}^3\times {\mathbb{S}}^1$ with spontaneously broken $\mathcal{C}$, $\mathcal{P}$, and $\mathcal{T}$ symmetries. We also compute the fermion zero modes in the background of monopole-instantons. The monopoles and their composites (topological molecules) proliferate in the vacuum leading to the confinement of electric charges. Interestingly enough, some theories have also accidental degenerate vacua, which are not related by any symmetry. These vacua admit different numbers of fermionic zero modes, and hence, different kinds of topological molecules. The lack of symmetry, however, indicates that such degeneracy might be lifted by higher order corrections.

    ↳ hep-thhep-lathep-phJHEP(2017)·19 citations
20. 20*

    Effect of the Early Reionization on the Cosmic Microwave Background and Cosmological Parameter Estimates

    Qing-Guo Huang🇨🇳 · Ke Wang🇨🇳

    The early reionization (ERE) is supposed to be a physical process which happens after recombination, but before the instantaneous reionization caused by the first generation of stars. We investigate the effect of the ERE on the temperature and polarization power spectra of cosmic microwave background (CMB), and adopt principal components analysis (PCA) to model-independently reconstruct the ionization history during the ERE. In addition, we also discuss how the ERE affects the cosmological parameter estimates, and find that the ERE does not impose any significant influences on the tensor-to-scalar ratio $r$ and the neutrino mass at the sensitivities of current experiments. The better CMB polarization data can be used to give a tighter constraint on the ERE and might be important for more precisely constraining cosmological parameters in the future.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2017)·4 citations
21. 21*

    Six-quark structure of $d^{\ast }(2380)$ in chiral constituent quark model

    Qi-Fang Lü🇨🇳 · Fei Huang🇨🇳 · Yu-Bing Dong🇨🇳 · Peng-Nian Shen🇨🇳 · Zong-Ye Zhang🇨🇳

    The structure of $d^{\ast }(2380)$ is re-studied with the single cluster structure in the chiral SU(3) quark model which has successfully been employed to explain the $N-N$ scattering data and the binding energy of deuteron. The binding behavior of such a six quark system is solved by using a variational method. The trial wave function is chosen to be a combination of a basic spherical symmetric component of $[(0s{)}^6{]}_{orb}$ in the orbital space with $0\hslash \omega$ excitation and an inner structural deformation component of $[(0s{)}^5(1s){]}_{orb}$ and $[(0s{)}^4(0p{)}^2{]}_{orb}$ in the orbital space with $2\hslash \omega$ excitation, both of which are in the spatial [6] symmetry. It is shown that the mass of the system is about $2356$ MeV, which is qualitative consistent with the result both from the two-cluster configuration calculation and from the data measured by the WASA Collaborations. This result tells us that as long as the medium-range interaction due to the chiral symmetry consideration is properly introduced, the mass of system will be reduced in a rather large extent. It also implies that the observed $d^{\ast }$ is a six-quark bound state with respect to the $\Delta \Delta$ threshold, which again supports the conclusion that $d^{\ast }$ is a hexaquark dominant state.

    ↳ nucl-thhep-phnucl-exPRD(2017)·26 citations
22. 22*

    Lattice Calculations of Heavy Quark Potential at Finite Temperature

    P. Petreczky🇺🇸 · J. Weber🇩🇪

    We report on the lattice calculations of the heavy quark potential at $T>0$ in 2+1 flavor QCD at physical quark masses using the Highly Improved Staggered Quark discretization. We study in detail the systematic effects in the determination of the real and imaginary parts of the potential when using the moment method.

    ↳ hep-lathep-phNPA(2017)·22 citations
23. 23*

    Right-handed neutrinos: the hunt is on!

    P. Mermod (for the SHiP Collaboration)🇨🇭

    The possibility of the existence of right-handed neutrinos remains one of the most important open questions in particle physics, as they can help elucidate the problems of neutrino masses, matter-antimatter asymmetry, and dark matter. Interest in this topic has been increasing in recent years with the proposal of new experimental avenues by which right-handed neutrinos with masses below the electroweak scale could be detected directly using displaced-vertex signatures. At the forefront of such endeavours, the proposed SHiP proton beam-dump experiment is designed for a large acceptance to new weakly-coupled particles and low backgrounds. It is capable of probing right-handed neutrinos with masses below 5~GeV and mixings several orders of magnitude smaller than current constraints, in regions favoured by cosmology. To probe higher masses (up to 30~GeV), a promising novel approach is to identify displaced vertices from right-handed neutrinos produced in $W$ decays at LHC experiments.

    ↳ hep-exhep-ph10 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.