Fri·Jun 30, 2017Friday·June 30, 2017

1. 01*

   Reevaluation of the hadronic vacuum polarisation contributions to the Standard Model predictions of the muon g-2 and alpha(mZ) using newest hadronic cross-section data

   Michel Davier🇫🇷 · Andreas Hoecker🇨🇭 · Bogdan Malaescu🇫🇷 · Zhiqing Zhang🇫🇷

   We reevaluate the hadronic vacuum polarisation contributions to the muon magnetic anomaly and to the running of the electromagnetic coupling constant at the Z-boson mass. We include newest e+e- to hadrons cross-section data (among others) from the BABAR and VEPP-2000 experiments. For the muon (g-2)/2 we find for the lowest-order hadronic contribution (693.1 +- 3.4) 10^-10, improving the precision of our previous evaluation by 21%. The full Standard Model prediction differs by 3.5 sigma from the experimental value. The five-quark hadronic contribution to alpha(mZ) is evaluated to be (276.0 +- 0.9) 10^-4.

   hep-phEPJC(2017)·745 citations
2. 02*

   QCD corrections to massive color-octet vector boson pair production

   Ayres Freitas🇺🇸 · Daniel Wiegand🇺🇸

   This paper describes the calculation of the next-to-leading order (NLO) QCD corrections to massive color-octet vector boson pair production at hadron colliders. As a concrete framework, a two-site coloron model with an internal parity is chosen, which can be regarded as an effective low-energy approximation of Kaluza-Klein gluon physics in universal extra dimensions. The renormalization procedure involves several subtleties, which are discussed in detail. The impact of the NLO corrections is relatively modest, amounting to a reduction of 11-14% in the total cross-section, but they significantly reduce the scale dependence of the LO result.

   hep-phhep-exJHEP(2017)·5 citations
3. 03*

   (Machine) Learning to Do More with Less

   Timothy Cohen🇺🇸 · Marat Freytsis🇺🇸 · Bryan Ostdiek🇺🇸

   Determining the best method for training a machine learning algorithm is critical to maximizing its ability to classify data. In this paper, we compare the standard "fully supervised" approach (that relies on knowledge of event-by-event truth-level labels) with a recent proposal that instead utilizes class ratios as the only discriminating information provided during training. This so-called "weakly supervised" technique has access to less information than the fully supervised method and yet is still able to yield impressive discriminating power. In addition, weak supervision seems particularly well suited to particle physics since quantum mechanics is incompatible with the notion of mapping an individual event onto any single Feynman diagram. We examine the technique in detail -- both analytically and numerically -- with a focus on the robustness to issues of mischaracterizing the training samples. Weakly supervised networks turn out to be remarkably insensitive to systematic mismodeling. Furthermore, we demonstrate that the event level outputs for weakly versus fully supervised networks are probing different kinematics, even though the numerical quality metrics are essentially identical. This implies that it should be possible to improve the overall classification ability by combining the output from the two types of networks. For concreteness, we apply this technology to a signature of beyond the Standard Model physics to demonstrate that all these impressive features continue to hold in a scenario of relevance to the LHC.

   hep-phphysics.data-anstat.MLJHEP(2018)·89 citations
4. 04*

   Froggatt-Nielsen mechanism in a model with $SU(3{)}_c\times SU(3{)}_L\times U(1{)}_X$ gauge group

   Katri Huitu🇫🇮 · Niko Koivunen🇫🇮

   The models with the gauge group $SU(3{)}_c\times SU(3{)}_L\times U(1{)}_X$ (331-models) have been advocated to explain why there are three fermion generations in Nature. As such they can provide partial understanding of the flavour sector. The hierarchy of Yukawa-couplings in the Standard Model is another puzzle which remains without compelling explanation. We propose to use Froggatt-Nielsen -mechanism in a 331-model to explain both fundamental problems. It turns out that no additional representations in the scalar sector are needed to take care of this. The traditional 331-models predict scalar flavour changing neutral currents at tree-level. We show that they are strongly suppressed in our model.

   hep-phPRD(2018)·21 citations
5. 05*

   Neutrino dispersion relation in a magnetized multi-stream matter background

   Jose F. Nieves🇺🇸 · Yaithd D. Olivas🇲🇽 · Sarira Sahu🇲🇽

   We study the propagation of a neutrino in a medium that consists of two or more thermal backgrounds of electrons and nucleons moving with some relative velocity, in the presence of a static and homogeneous electromagnetic field. We calculate the neutrino self-energy and dispersion relation using the linear thermal Schwinger propagator, we give the formulas for the dispersion relation and discuss general features of the results obtained, in particular the effects of the stream contributions. As a specific example we discuss in some detail the case of a magnetized two-stream electron, i.e., two electron backgrounds with a relative velocity $\vec{v}$ in the presence of a magnetic field. For a neutrino propagating with momentum $\vec{k}$, in the presence of the stream the neutrino dispersion relation acquires an anisotropic contribution of the form $\hat{k}\cdot \vec{v}$ in addition to the well known term $\hat{k}\cdot \vec{B}$, as well as an additional contribution proportional to $\vec{B}\cdot \vec{v}$. We consider the contribution from a nucleon stream background as an example of other possible stream backgrounds, and comment on possible generalizations to take into account the effects of inhomogeneous fields. We explain why a term of the form $\hat{k}\cdot (\vec{v}\times \vec{B})$ does not appear in the dispersion relation in the constant field case, while a term of similar form can appear in the presence of an inhomogeneous field involving its gradient.

   hep-phEPJC(2018)·0 citations
6. 06*

   Dark matter spin determination with directional direct detection experiments

   Riccardo Catena🇸🇪 · Jan Conrad🇸🇪 · Christian Döring🇩🇪 · Alfredo Davide Ferella🇸🇪 · Martin B. Krauss🇸🇪

   If the dark matter particle has spin 0, only two types of WIMP-nucleon interaction can arise from the non-relativistic reduction of renormalisable single-mediator models for dark matter-quark interactions. Based on this crucial observation, we show that about 100 signal events at next generation directional detection experiments can be enough to enable a $2\sigma$ rejection of the spin 0 dark matter hypothesis in favour of alternative hypotheses where the dark matter particle has spin 1/2 or 1. In this context directional sensitivity is crucial, since anisotropy patterns in the sphere of nuclear recoil directions depend on the spin of the dark matter particle. For comparison, about 100 signal events are expected in a CF${}_4$ detector operating at a pressure of 30 torr with an exposure of approximately 26,000 cubic-meter-detector days for WIMPs of 100 GeV mass and a WIMP-Fluorine scattering cross-section of 0.25 pb. Comparable exposures are within reach of an array of cubic meter time projection chamber detectors.

   hep-phastro-ph.COPRD(2018)·20 citations
7. 07*

   Neutrino propagation in an electron background with an inhomogeneous magnetic field

   Jose F. Nieves🇺🇸 · Sarira Sahu🇲🇽

   We study the electromagnetic coupling of a neutrino that propagates in a two-stream electron background medium. Specifically, we calculate the electromagnetic vertex function for a medium that consists of a \emph{normal} electron background plus another electron \emph{stream} background that is moving with a velocity four-vector $v^{\mu }$ relative to the normal background. The results can be used as the basis for studying the neutrino electromagnetic properties and various processes in such a medium. As an application, we calculate the neutrino dispersion relation in the presence of an external magnetic field ($\vec{B}$), focused in the case in which $B$ is inhomogeneous, keeping only the terms of the lowest order in $1/m_W^2$ and linear in the $B$ and its gradient. We show that the dispersion relation contains additional anisotropic terms involving the derivatives of $\vec{B}$, such as the gradient of $\hat{k}\cdot (\vec{v}\times \vec{B})$, which involve the stream background velocity, and a term of the form $\hat{k}\cdot (\nabla \times \vec{B})$ that can be present in the absence of the stream background, in addition to a term of the form $\hat{k}\cdot \vec{v}$ and the well known term $\hat{k}\cdot \vec{B}$ that arises in the constant $\vec{B}$ case. The derivative-dependent terms are even under a $CP$ transformation. As a result, in contrast to the latter two just mentioned, they depend on the sum of the particle and antiparticle densities and therefore can be non-zero in a $CP$-symmetric medium in which the particle and antiparticle densities are equal.

   hep-phEPJC(2018)·5 citations
8. 08*

   Light Meson Masses using AdS/QCD modified Soft Wall Model

   Santiago Cortés🇨🇴 · Miguel Ángel Martín Contreras🇨🇴 · José Rolando Roldán🇨🇴

   We analyze light vector and scalar meson mass spectra using a novel approach where a modified soft wall model with a UV-cutoff is considered. Including this cutoff introduces an extra energy scale. For this model, we found that the masses for the scalar and vector spectra are well fitted within a very small RMS error for 14 of these states, with non-linear trajectories given by two common parameters, the UV locus $z_0$ and the quadratic dilaton profile slope $\kappa$. We concluded that in this model the $f_0(500)$ scalar resonance cannot be fitted holographycally as a $q\overline{q}$ state since we could not find a trajectory that included this pole. This result is in agreement with the most recent phenomenological and theoretical methods.

   hep-phhep-thPRD(2017)·7 citations
9. 09*

   Top-quark pair production cross sections at NNLO+NNLL in pPb collisions at $\sqrt{s_{NN}}$ = 8.16 TeV

   David d'Enterria🇨🇭

   Total and fiducial top pair ($t\bar{t}$) production cross sections in proton-lead (pPb) collisions at $\sqrt{s_{NN}}$ = 8.16 TeV are computed at next-to-next-to-leading-order (NNLO) accuracy including next-to-next-to-leading-log (NNLL) gluon resummation, using the CT14 and CT10 proton parton distribution functions (PDF), and the EPPS16 and EPS09 nuclear PDF parametrizations for the lead ion. The total cross sections amount to $\sigma (pPb\to t\bar{t}+X)=59.0\pm 5.3$(CT14+EPPS16)${}_{-2.1}^{+1.6}$(scale) nb, and $57.5\pm {}_{-3.3}^{+4.3}$(CT10+EPS09)${}_{-2.0}^{+1.5}$(scale) nb, with small modifications with respect to the result computed using the free proton PDF alone. The normalized ratio of pPb to pp cross sections (nuclear modification factor) is $R_{pPb}=1.04{}_{\pm 0.03(EPS09)}^{\pm 0.07(EPPS16)}$. In the lepton+jets decay mode, $t\bar{t}\to b\bar{b}W(\ell \nu )W(q{\bar{q}}^{\prime })$, one expects $\sim$600 $t\bar{t}$ events in the 180 nb${}^{-1}$ integrated luminosity collected in pPb collisions at the LHC so far, after typical acceptance and efficiency losses. Differential cross sections at NLO accuracy are presented as a function of transverse momentum and rapidity of the top quarks, and of their decay b-jets and isolated leptons.

   hep-phhep-exnucl-exnucl-thNPA(2019)·4 citations
10. 10*

    Advantages of Unity With SU(4)-Color: Reflections Through Neutrino Oscillations, Baryogenesis and Proton Decay

    Jogesh C. Pati🇺🇸

    As a tribute to Abdus Salam, I recall the initiation in 1972-73 of the idea of grand unification based on the view that lepton number is the fourth color. Motivated by aesthetic demands, these attempts led to the suggestion that the existing $SU(2)\times U(1)$ symmetry be extended minimally to the quark-lepton and left-right symmetric non-Abelian gauge structure $G(2,2,4)=SU(2{)}_L\times SU(2{)}_R\times SU(4)$-color. This unified members of a family within a single L-R self-conjugate multiplet. It also explained: the quantization of electric charge, the co-existence of quarks and leptons, and that of their three forces, while providing the appealing possibility that nature is fundamentally left-right symmetric. The minimal extension of $G(2,2,4)$ to a simple group is given by the symmetry $SO(10)$ that came a year later. The advantages of the core symmetry $G(2,2,4)$, including those listed above (which are of course retained by $SO(10)$), are noted. These include the introductions of: (i){ \it the right-handed neutrino as a compelling member of each family}, (ii) (B-L) as a local symmetry, and (iii) the relation $m({\nu }^{\tau }{)}_{Dirac}=m_{top}$. These three features, as well as the gauge coupling unification scale, are crucially needed to understand the tiny mass-scales of the neutrino oscillations within the seesaw mechanism, and to implement successfully the mechanism of baryogenesis via leptogenesis. Implications of a well-motivated class of models based on supersymmetric $SO(10)$ or a string-unified $G(2,2,4)$ symmetry in 4D for (a) gauge coupling unification, (b) fermion masses and mixings, (c) neutrino osillations, (d) baryogenesis via leptogenesis, and last but not least (e) proton decay are presented. Recent works on the latter providing upper limits on proton lifetimes suggest that the potential for discovery of proton decay in the next-generation detectors would be high.

    hep-phhep-thInt.J.Mod.Phys.A(2017)·19 citations
11. 11*

    MSSM vs. NMSSM in $\Delta F=2$ transitions

    Jacky Kumar🇮🇳

    We study deviations between MSSM and NMSSM in the predictions of $\Delta F=2$ processes. We found that there can be two sources which can cause such deviations, \emph{i.e}, due to certain neutralino-gluino cross box diagrams and due to well known double penguin diagrams. Both are effective at large $\tan \beta$. In addition to this, taking into account 8 TeV direct search constraints from the heavy Higgs searches, we study the maximum allowed MFV like new physics (NP) effects on $\Delta M_s$ in the two models. In NMSSM such NP effects can be as large as $25\%$, on the other hand in MSSM such large contributions are severely constrained.

    hep-phPoS(2017)·0 citations
12. 12*

    Mass spectra of meson molecular states for heavy and light sectors

    S. Rahmani🇮🇷 · H. Hassanabadi🇮🇷

    We obtain mass spectra of the light and heavy meson-antimeson (molecular states) sectors by using a nonrelativistic potential model with Coulomb and one pion exchange potential terms for meson-meson interaction. The digamma decay widths are also obtained for the light sector. We compare our results with available experimental and theoretical data.

    hep-phnucl-thCPC(2017)·3 citations
13. 13*

    Light sterile neutrinos, dark matter, and new resonances in a $U(1)$ extension of the MSSM

    A. Hebbar🇺🇸 · G. Lazarides🇬🇷 · Q.Shafi🇺🇸

    We present ${\psi }^{\prime }$MSSM, a model based on a $U(1{)}_{{\psi }^{\prime }}$ extension of the minimal supersymmetric standard model. The gauge symmetry $U(1{)}_{{\psi }^{\prime }}$, also known as $U(1{)}_N$, is a linear combination of the $U(1{)}_{\chi }$ and $U(1{)}_{\psi }$ subgroups of $E_6$. The model predicts the existence of three sterile neutrinos with masses $\lesssim 0.1\mathrm{eV}$, if the $U(1{)}_{{\psi }^{\prime }}$ breaking scale is of order 10 TeV. Their contribution to the effective number of neutrinos at nucleosynthesis is $\Delta N_{\nu }\simeq 0.29$. The model can provide a variety of possible cold dark matter candidates including the lightest sterile sneutrino. If the $U(1{)}_{{\psi }^{\prime }}$ breaking scale is increased to $10^3\mathrm{TeV}$, the sterile neutrinos, which are stable on account of a $Z_2$ symmetry, become viable warm dark matter candidates. The observed value of the standard model Higgs boson mass can be obtained with relatively light stop quarks thanks to the D-term contribution from $U(1{)}_{{\psi }^{\prime }}$. The model predicts diquark and diphoton resonances which may be found at an updated LHC. The well-known $\mu$ problem is resolved and the observed baryon asymmetry of the universe can be generated via leptogenesis. The breaking of $U(1{)}_{{\psi }^{\prime }}$ produces superconducting strings that may be present in our galaxy. A $U(1)$ R symmetry plays a key role in keeping the proton stable and providing the light sterile neutrinos.

    hep-phastro-ph.COPRD(2017)·9 citations
14. 14*

    Inflation and Leptogenesis in a $U(1)$-enhanced supersymmetric model

    Y. H. Ahn🇰🇷

    Motivated by the flavored Peccei-Quinn symmetry for unifying flavor physics and string theory, we investigate a supersymmetric extension of standard model (SM) for an explanation of inflation and leptogenesis by introducing $U(1)$ symmetries such that the $U(1)$-$[gravity{]}^2$ anomaly-free condition together with the SM flavor structure demands additional sterile neutrinos as well as no axionic domain-wall problem. Such additional neutrinos may play a crucial role as a bridge between leptogenesis and new neutrino oscillations along with high energy cosmic events. In a realistic moduli stabilization, we show that the moduli backreaction effect on the inflationary potential leads to the energy scale of inflation with the inflaton mass in a way that the power spectrum of the curvature perturbation and the scalar spectral index are to be well fitted with the latest Planck observation. We suggest that a new leptogenesis scenario could naturally be implemented via Affleck-Dine mechanism. So we show that the resultant baryon asymmetry, constrained by the sum of active neutrino masses and new high energy neutrino oscillations, crucially depends on the reheating temperature $T_{\mathrm{reh}}$. And we show that the model has a preference on $T_{\mathrm{reh}}\sim 10^3$ TeV, which is compatible with the required $T_{\mathrm{reh}}$ to explain the baryon asymmetry of the Universe.

    hep-phPRD(2019)·5 citations
15. 15*

    Strong First Order EWPT and Strong Gravitational Waves in $Z_3$-symmetric Singlet Scalar Extension

    Zhaofeng Kang🇰🇷 · P. Ko🇰🇷 · Toshinori Matsui🇰🇷

    The nature of electroweak (EW) phase transition (PT) is of great importance. It may give a clue to the origin of baryon asymmetry if EWPT is strong first order. Although it is second order within the standard model (SM), a great many extensions of the SM are capable of altering the nature. Thus, gravitational wave (GW), which is supposed to be relics of strong first order PT, is a good complementary probe to new physics beyond SM (BSM). We in this paper elaborate the patterns of strong first order EWPT in the next to simplest extension to the SM Higgs sector, by introducing a $Z_3$-symmetric singlet scalar. We find that, in the $Z_3$-symmetric limit, the tree level barrier could lead to strong first order EWPT either via three or two-step PT. Moreover, they could produce two sources of GW, despite of the undetectability from the first-step strong first order PT for the near future GW experiments. But the other source with significant supercooling which then gives rise to $\alpha \sim \mathcal{O}(0.1)$ almost can be wholly covered by future space-based GW interferometers such as eLISA, DECIGO and BBO.

    hep-phastro-ph.COJHEP(2018)·83 citations
16. 16*

    Yukawas and trilinear Higgs terms from loops

    Ulrich Haisch🇬🇧

    It is illustrated how LHC precision measurements of rates and distributions in single-Higgs production can be used to constrain the charm Yukawa as well as the Higgs trilinear coupling.

    hep-phhep-ex7 citations
17. 17*

    Mass spectra for $qc\bar{q}\bar{c}$, $sc\bar{s}\bar{c}$, $qb\bar{q}\bar{b}$, $sb\bar{s}\bar{b}$ tetraquark states with $J^{PC}=0^{++}$ and $2^{++}$

    Wei Chen🇨🇳 · Hua-Xing Chen🇨🇳 · Xiang Liu🇨🇳 · T. G. Steele🇨🇦 · Shi-Lin Zhu🇨🇳

    We have studied the mass spectra of the hidden-charm/bottom $qc\bar{q}\bar{c}$, $sc\bar{s}\bar{c}$ and $qb\bar{q}\bar{b}$, $sb\bar{s}\bar{b}$ tetraquark states with $J^{PC}=0^{++}$ and $2^{++}$ in the framework of QCD sum rules. We construct ten scalar and four tensor interpolating currents in a systematic way and calculate the mass spectra for these tetraquark states. The $X^{\ast }(3860)$ may be either an isoscalar tetraquark state or ${\chi }_{c0}(2P)$. If the $X^{\ast }(3860)$ is a tetraquark candidate, our results prefer the $0^{++}$ option over the $2^{++}$ one. The $X(4160)$ may be classified as either the scalar or tensor $qc\bar{q}\bar{c}$ tetraquark state while the $X(3915)$ favors a $0^{++}$ $qc\bar{q}\bar{c}$ or $sc\bar{s}\bar{c}$ tetraquark assignment over the tensor one. The $X(4350)$ can not be interpreted as a $sc\bar{s}\bar{c}$ tetraquark with either $J^{PC}=0^{++}$ or $2^{++}$.

    hep-phhep-exPRD(2017)·47 citations
18. 18*

    Loop inflection-point inflation

    Konstantinos Dimopoulos🇬🇧 · Charlotte Owen🇬🇧 · Antonio Racioppi🇪🇪

    A novel inflection-point inflation model is analysed. The model considers a massless scalar field, whose self-coupling's running is stabilised by a non-renormalisable operator. The running is controlled by a fermion loop. We find that successful inflation is possible for a natural value of the Yukawa coupling $y\simeq 4\times 10^{-4}$. The necessary fine-tuning is only $\sim 10^{-6}$, which improves on the typical tuning of inflection-point inflation models, such as MSSM inflation. The model predicts a spectral index within the 1-$\sigma$ bound of the latest CMB observations, with negligible tensors ($r\sim 10^{-(9-10)}$). These results are largely independent of the order of the stabilising non-renormalisable operator.

    hep-phAstropart.Phys.(2018)·27 citations
19. 19*

    Excited neutrino search potential of the FCC-based electron-hadron colliders

    A. Caliskan🇹🇷

    The production potential of the excited neutrinos at the FCC-based electron-hadron colliders, namely the ERL60$\otimes$FCC with $\sqrt{s}=3.46$ TeV, the ILC$\otimes$FCC with $\sqrt{s}=10$ TeV, and the PWFA-LC$\otimes$FCC with $\sqrt{s}=31.6$ TeV, has been analyzed. The branching ratios of the excited neutrinos have been calculated for the different decay channels and shown that the dominant channel is ${\nu }^{\star }\to e{W}^{+}$. We have calculated the production cross sections with the process of $ep\to {\nu }^{\star }q\to e{W}^{+}q$ and the decay widths of the excited neutrinos with the process of ${\nu }^{\star }\to e{W}^{+}$. The signals and corresponding backgrounds are studied in detail to obtain accessible mass limits. It is shown that the discovery limits obtained on the mass of the excited neutrino are $2452$ GeV for $L_{int}=100$ $f{b}^{-1}$, $5635$ GeV for $L_{int}=10$ $f{b}^{-1}$ ($6460$ GeV for $L_{int}=100$ $f{b}^{-1}$), and $10200$ GeV for $L_{int}=1$ $f{b}^{-1}$ ($13960$ GeV for $L_{int}=10$ $f{b}^{-1}$), for the center-of-mass energies of $3.46$, $10$, and $31.6$ TeV, respectively.

    hep-phAdv.High Energy Phys.(2017)·10 citations
20. 20*

    Can the symmetry breaking in the SM be determined by the Top-Higgs Yukawa interaction?

    Jose Carlos Suarez Cortina🇨🇺 · Denys Arrebato🇨🇺 · Alejandro Cabo🇨🇺

    In this letter, we first resume the results of a previous article (EPJC(2011)71:1620). That work considered a simple model of QCD including a Yukawa interaction with a scalar field. Its two loop effective potential for the scalar field, predicted a 126 GeV Higgs mass after the minimum of the potential was fixed at a mean scalar field giving a 175 GeV Top quark mass. However, a high value of the strong coupling was required (\alpha=g^2/(4 \pi) close to 1) to get these values. After reviewing the results of this study, an idea for extending the work is simply advanced here: to consider the running strong coupling, in order to decide whether or not, the usual values of the strong interactions have the chance of justifying the experimentally known values of the Higgs and Top quark masses. It is underlined that a positive result of the proposed task will suggests the possibility of basing the SM breaking of symmetry, on the so called "second minimum" of this model. This could also identify the essential role of QCD in this effect. Results of the further examination of this question will be presented elsewhere.

    hep-phhep-th0 citations
21. 21*

    Mellin-Barnes meets Method of Brackets: A novel approach to Mellin-Barnes representations of Feynman integrals

    Mario Prausa🇩🇪

    In this paper, we present a new approach to the construction of Mellin-Barnes representations for Feynman integrals inspired by the Method of Brackets. The novel technique is helpful to lower the dimensionality of Mellin-Barnes representations in complicated cases, some examples are given.

    hep-phEPJC(2017)·19 citations
22. 22*

    Using hadron-in-jet data in a global analysis of $D^{\ast }$ fragmentation functions

    Daniele P. Anderle🇬🇧 · Tom Kaufmann🇩🇪 · Felix Ringer🇺🇸 · Marco Stratmann🇩🇪 · Ivan Vitev🇺🇸

    We present a novel global QCD analysis of charged $D^{\ast }$-meson fragmentation functions at next-to-leading order accuracy. This is achieved by making use of the available data for single-inclusive $D^{\ast }$-meson production in electron-positron annihilation, hadron-hadron collisions, and, for the first time, in-jet fragmentation in proton-proton scattering. It is shown how to include all relevant processes efficiently and without approximations within the Mellin moment technique, specifically for the in-jet fragmentation cross section. The presented technical framework is generic and can be straightforwardly applied to future analyses of fragmentation functions for other hadron species, as soon as more in-jet fragmentation data become available. We choose to work within the Zero Mass Variable Flavor Number Scheme which is applicable for sufficiently high energies and transverse momenta. The obtained optimum set of parton-to-$D^{\ast }$ fragmentation functions is accompanied by Hessian uncertainty sets which allow one to propagate hadronization uncertainties to other processes of interest.

    hep-phhep-exnucl-exnucl-thPRD(2017)·73 citations
23. 23*

    High-energy neutrino attenuation in the Earth and its associated uncertainties

    Aaron C. Vincent🇬🇧 · Carlos A. Argüelles🇺🇸 · Ali Kheirandish🇺🇸

    We describe nuFATE Neutrino Fast Attenuation Through Earth, a very rapid method of accurately computing the attenuation of high-energy neutrinos during their passage through Earth to detectors such as IceCube, ANTARES or KM3Net, including production of secondary neutrinos from ${\tau }^{\pm }$ lepton decay. We then use this method to quantify the error on attenuation due to uncertainties in the isotropic neutrino spectrum, the composition of the Earth, and the parton distribution functions. We show that these can be as large as 20%, which can significantly impact reconstructed astrophysical neutrino parameters, as well as searches for new physics. An implementation of this algorithm is provided as a public code.

    hep-phastro-ph.HEJCAP(2017)·60 citations
24. 24*

    Electroweak baryogenesis in the Z3-invariant NMSSM

    Sujeet Akula🇦🇺 · Csaba Balázs🇦🇺 · Liam Dunn🇦🇺 · Graham White🇦🇺

    We calculate the baryon asymmetry of the Universe in the Z3-invariant Next-to-Minimal Supersymmetric Standard Model where the interactions of the singlino provide the necessary source of charge and parity violation. Using the closed time path formalism, we derive and solve transport equations for the cases where the singlet acquires a vacuum expectation value (VEV) before and during the electroweak phase transition. We perform a detailed scan to show how the baryon asymmetry varies throughout the relevant parameter space. Our results show that the case where the singlet acquires a VEV during the electroweak phase transition typically generates a larger baryon asymmetry, although we expect that the case where the singlet acquires a VEV first is far more common for any model in which parameters unify at a high scale. Finally, we examine the dependence of the baryon asymmetry on the three-body interactions involving gauge singlets.

    hep-phJHEP(2017)·28 citations
25. 25*

    Optimizing Event Selection with the Random Grid Search

    Pushpalatha C. Bhat🇺🇸 · Harrison B. Prosper🇺🇸 · Sezen Sekmen🇰🇷 · Chip Stewart🇺🇸

    The random grid search (RGS) is a simple, but efficient, stochastic algorithm to find optimal cuts that was developed in the context of the search for the top quark at Fermilab in the mid-1990s. The algorithm, and associated code, have been enhanced recently with the introduction of two new cut types, one of which has been successfully used in searches for supersymmetry at the Large Hadron Collider. The RGS optimization algorithm is described along with the recent developments, which are illustrated with two examples from particle physics. One explores the optimization of the selection of vector boson fusion events in the four-lepton decay mode of the Higgs boson and the other optimizes SUSY searches using boosted objects and the razor variables.

    hep-phComput.Phys.Commun.(2018)·5 citations
26. 26*

    Effective horizons, junction conditions and large-scale magnetism

    Massimo Giovannini🇨🇭

    The quantum mechanical generation of hypermagnetic and hyperlectric fields in four-dimensional conformally flat background geometries rests on the simultaneous continuity of the effective horizon and of the extrinsic curvature across the inflationary boundary. The junction conditions for the gauge fields are derived in general terms and corroborated by explicit examples with particular attention to the limit of a sudden (but nonetheless continuous) transition of the effective horizon. After reducing the dynamics to a pair of integral equations related by duality transformations, we compute the power spectra and deduce a novel class of logarithmic corrections which turn out to be, however, numerically insignificant and overwhelmed by the conductivity effects once the gauge modes reenter the effective horizon. In this perspective the magnetogenesis requirements and the role of the postinflationary conductivity are clarified and reappraised. As long as the total duration of the inflationary phase is nearly minimal, quasi-flat hypermagnetic power spectra are comparatively more common than in the case of vacuum initial data.

    ↳ hep-thastro-ph.COgr-qchep-phEPJC(2017)·1 citation

* 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.