Tue·Sep 27, 2016Tuesday·September 27, 2016

1. 01*

   New Angles on Energy Correlation Functions

   Ian Moult🇺🇸 · Lina Necib🇺🇸 · Jesse Thaler🇺🇸

   Jet substructure observables, designed to identify specific features within jets, play an essential role at the Large Hadron Collider (LHC), both for searching for signals beyond the Standard Model and for testing QCD in extreme phase space regions. In this paper, we systematically study the structure of infrared and collinear safe substructure observables, defining a generalization of the energy correlation functions to probe $n$-particle correlations within a jet. These generalized correlators provide a flexible basis for constructing new substructure observables optimized for specific purposes. Focusing on three major targets of the jet substructure community---boosted top tagging, boosted $W/Z/H$ tagging, and quark/gluon discrimination---we use power-counting techniques to identify three new series of powerful discriminants: $M_i$, $N_i$, and $U_i$. The $M_i$ series is designed for use on groomed jets, providing a novel example of observables with improved discrimination power after the removal of soft radiation. The $N_i$ series behave parametrically like the $N$-subjettiness ratio observables, but are defined without respect to subjet axes, exhibiting improved behavior in the unresolved limit. Finally, the $U_i$ series improves quark/gluon discrimination by using higher-point correlators to simultaneously probe multiple emissions within a jet. Taken together, these observables broaden the scope for jet substructure studies at the LHC.

   hep-phhep-exJHEP(2016)·202 citations
2. 02*

   Monojet searches for momentum-dependent dark matter interactions

   Daniele Barducci🇫🇷 · Aoife Bharucha🇫🇷 · Nishita Desai🇩🇪 · Michele Frigerio🇫🇷 · Benjamin Fuks🇫🇷 · Andreas Goudelis🇫🇷 · Suchita Kulkarni🇦🇹 · Giacomo Polesello🇮🇹 · Dipan Sengupta🇫🇷

   We consider minimal dark matter scenarios featuring momentum-dependent couplings of the dark sector to the Standard Model. We derive constraints from existing LHC searches in the monojet channel, estimate the future LHC sensitivity for an integrated luminosity of 300 fb${}^{-1}$, and compare with models exhibiting conventional momentum-independent interactions with the dark sector. In addition to being well motivated by (composite) pseudo-Goldstone dark matter scenarios, momentum-dependent couplings are interesting as they weaken direct detection constraints. For a specific dark matter mass, the LHC turns out to be sensitive to smaller signal cross-sections in the momentum-dependent case, by virtue of the harder jet transverse-momentum distribution.

   hep-phJHEP(2017)·27 citations
3. 03*

   Applying Bayesian Inference to Galileon Solutions of the Muon Problem

   Henry Lamm🇺🇸

   We derive corrections to atomic energy levels from disformal couplings in Galileon theories. Through Bayesian inference, we constrain the cutoff radii and Galileon scale via these corrections. To connect different atomic systems, we assume the various cutoff radii related by a one-parameter family of solutions. This introduces a new parameter $\alpha$ which is also constrained. In this model, we predict shifts to muonic helium of $\delta E_{H{e}^3}=1.97_{-1.87}^{+9.28}$ meV and $\delta E_{H{e}^4}=1.69_{-1.61}^{+9.25}$ meV as well as for true muonium, $\delta E_{TM}=0.06_{-0.05}^{+0.46}$ meV.

   hep-phPRD(2016)·6 citations
4. 04*

   New LUX result compensates LHC searches for exotic quarks

   Chuan-Ren Chen🇹🇼 · Ming-Jie Li🇹🇼

   The scenario of the compressed mass spectrum between heavy quark and dark matter is a challenge for LHC searches. However, the elastic scattering cross section between dark matter and nuclei in dark matter direct detection experiments can be enhanced with nearly degenerate masses between heavy quarks and dark matter. In this paper, we illustrate such scenario with a vector dark matter, using the latest result from LUX 2016. The mass constraints on heavy quarks can be more stringent than current limits from LHC, unless the coupling strength is very small. However, the compress mass spectrum with allowed tiny coupling strength makes the decay lifetime of heavy quarks longer than the time scale of QCD hadronization.

   hep-phInt.J.Mod.Phys.A(2016)·3 citations
5. 05*

   Production of heavy sterile neutrinos from vector boson decay at electroweak temperatures

   Louis Lello🇺🇸 · Daniel Boyanovsky🇺🇸 · Robert D. Pisarski🇺🇸

   In the standard model extended with a seesaw mass matrix, we study the production of sterile neutrinos from the decay of vector bosons at $T\simeq M_{W,Z}$. We derive a general quantum kinetic equation for the production of sterile neutrinos and their effective mixing angles valid in a wide range of temperature, to all orders in interactions of the standard model, and to leading order mixing angle $\theta \ll 1$. Production rates and effective mixing angles depend sensitively on helicity. Positive helicity states interact more weakly with the medium and their effective mixing angle is not modified significantly whereas the mixing angle for negative helicity is strongly suppressed by the medium. If $M_s\lesssim 8.35\mathrm{MeV}$, there are fewer states with negative helicity produced than those with positive helicity. There is an MSW resonance in the absence of lepton asymmetry, but is screened by the damping rate, without production enhancement. Negative helicity states freeze-out at $T_f^{-}\simeq 5\mathrm{GeV}$ and positive helicity states freeze-out at $T_f^{+}\simeq 8\mathrm{GeV}$, both distributions are far from thermal. Negative helicity states feature a broader momentum distribution than that for those with positive helicity. Sterile neutrinos produced via vector boson decay do not satisfy the abundance, lifetime and cosmological constraints to be the sole dark matter component in the universe but might solve the ${}^{7}Li$ problem, albeit at the very edge of the possible parameter space. A heavy sterile neutrino with a mass of a few MeV could decay into light sterile neutrinos, of a few keV in mass, that contribute to warm dark matter. We argue that heavy sterile neutrinos with lifetime $\le 1/H_0$ reach local thermodynamic equilibrium.

   hep-phastro-ph.COPRD(2017)·18 citations
6. 06*

   On the parton picture of Froissart asymptotic behavior

   O.V. Kancheli🇷🇺

   The Froissart (\F) asymptotic behavior of high energy cross-sections, if considered in a parton picture, is usually represented as a kind of behavior that occurs in the process of a collision of two almost black disks, filled with partons, when radiuses of these \F - disks grow proportional to log's of there energies. In this article we briefly summarize the main asymptotic properties of \F - disks that one can expect in QCD. ~~Then we consider if it is possible to guarantee the boost-invariance of transparency $T(s,b)=1-{\sigma }_{in}(s,b)$, where ${\sigma }_{in}(s,b)$ is the total inelastic cross-section at a definite impact parameter $b$, in process of collision of two such \F-disks. Such a question arise because the mean transverse area of the overlapping of colliding \F- disks, at the same impact parameter b and total energy $\sqrt{s}$~,~ is varying with the Lorentz frame. ~~We show that the value of $T(s,b)$ is not boost-invariant at some $b$ close to the \F- disk border for the \F- disks usually expected in QCD. As result the \F type behavior seems contradictory, or the multiparton system in the high energy Fock wave function must be arranged in rather unusual way.

   hep-ph5 citations
7. 07*

   Effects of Majorana Physics on the UHE ${\nu }_{\tau }$ Flux Traversing the Earth

   Lucía Duarte🇺🇾 · Ismael Romero🇦🇷 · Gabriel Zapata🇦🇷 · Oscar A. Sampayo🇦🇷

   We study the effects produced by sterile Majorana neutrinos on the ${\nu }_{\tau }$ flux traversing the Earth, considering the interaction between the Majorana neutrinos and the standard matter as modeled by an effective theory. The surviving tau-neutrino flux is calculated using transport equations including Majorana neutrino production and decay. We compare our results with the pure Standard Model interactions, computing the surviving flux for different values of the effective lagrangian couplings, considering the detected flux by IceCube for an operation time of ten years, and Majorana neutrinos with mass $m_N\sim m_{\tau }$.

   hep-phEPJC(2017)·4 citations
8. 08*

   Chiral phase transition in QED${}_3$ at finite temperature

   Wei Wei🇨🇳 · Hai-Xiao Xiao🇨🇳 · Hong-Shi Zong🇨🇳

   Chiral phase transition in (2+1)-dimensional quantum electrodynamics (QED${}_3$) at finite temperature is investigated in the framework of truncated Dyson-Schwinger equations (DSEs). We go beyond the widely used instantaneous approximation and adopt a method that retains the full frequency dependence of the fermion self-energy. We also take further step to include the effects of wave-function renormalizations and introduce a minimal dressing of the bare vertex. Finally, with the more complete solutions of the truncated DSEs, we revisit the study of chiral phase transition in finite-temperature QED${}_3$.

   hep-ph0 citations
9. 09*

   Neutrino Mass Sum Rules

   Martin Spinrath🇩🇪

   Neutrino mass sum rules are an important class of predictions in flavour models relating the Majorana phases to the neutrino masses. This leads, for instance, to enormous restrictions on the effective mass as probed in experiments on neutrinoless double beta decay. While up to now these sum rules have in practically all cases been taken to hold exactly, we will go here beyond that. While the effect of the renormalisation group running can be visible, the qualitative features do not change. This changes somewhat for model dependent corrections which might alter even the qualitative predictions but only for large corrections and a high neutrino mass scale close to the edge of the current limits. This finding backs up the solidity of the predictions derived in the literature apart from some exceptions, and it thus marks a very important step in deriving testable and robust predictions from neutrino flavour models.

   hep-phJ.Phys.Conf.Ser.(2017)·4 citations
10. 10*

    The polarization effects of the process $\tau \to K^{-}{\pi }^0{\nu }_{\tau }$ in the Nambu--Jona-Lasinio model

    A. A. Pivovarov🇷🇺 · O. V. Teryaev🇷🇺

    The polarization effects of the processes $\tau \to K^{-}{\pi }^0{\nu }_{\tau }$ are described in the framework of the Nambu--Jona-Lasinio model. The intermediate vector meson $K^{\ast }(892)$ is taken into account. The contribution of these effects to the differential decay width is obtained.

    hep-phJETP Lett.(2016)·3 citations
11. 11*

    Model-independent determination of the compositeness of near-threshold quasibound states

    Yuki Kamiya🇯🇵 · Tetsuo Hyodo🇯🇵

    We study the compositeness of near-threshold states to clarify the internal structure of exotic hadron candidates. Within the framework of effective field theory, we extend the Weinberg's weak-binding relation to include the nearby CDD (Castillejo-Dalitz-Dyson) pole contribution with the help of the Pade approximant. Finally, using the extended relation, we conclude that the CDD pole contribution to the Lambda(1405) baryon in the Kbar N amplitude is negligible.

    hep-phnucl-thJPS Conf.Proc.(2017)·0 citations
12. 12*

    Chiral Symmetry Restoration for the large-$N$ pion gas

    Santiago Cortés🇨🇱 · Angel Gómez Nicola🇪🇸 · John Morales🇨🇴

    We analyze chiral restoration within the $O(N+1)/O(N)$ Non-Linear Sigma Model for large $N$ as an effective theory for low-energy QCD at finite temperature $T$. The free energy is constructed diagramatically to $\mathcal{O}(T{M}^3)$ in the pion mass expansion, which allows to derive the quark condensate and the scalar susceptibility in the chiral limit. At this order, we do not have to deal with renormalization, neither from divergences from mass tadpoles nor from those of higher order loop contributions. Our results for the critical behaviour are consistent with expectations from lattice analysis and with previous works where the susceptibility is saturated by the thermal $f_0(500)$ pole.

    hep-phPRD(2016)·8 citations
13. 13*

    Form factors and transverse charge and magnetization densities in the hard-wall AdS/QCD model

    Chandan Mondal🇮🇳

    We present a study of the flavor form factors in the framework of a hard-wall AdS/QCD model and compare with the available experimental data. We obtain the flavor form factors by decomposing the Dirac and Pauli form factors for the nucleons using the charge and isospin symmetry. Further, we present a detailed study of the flavor structures of the charge and anomalous magnetization densities in the transverse plane. Both the unpolarized and the transversely polarized nucleons are considered here. We compare the AdS/QCD results with two standard phenomenological parametrizations.

    hep-phPRD(2016)·18 citations
14. 14*

    Relic abundance of MeV millicharged particles

    A.D. Dolgov🇷🇺 · A.S. Rudenko🇷🇺

    The relic abundance of light millicharged particles (MCPs) with the electric charge $e^{\prime }=5\cdot 10^{-5}e$ and with the mass slightly below or above the electron mass is calculated. The abundance depends on the mass ratio $\eta =m_X/m_e$ and for $\eta <1$ can be high enough to allow MCPs to be the cosmological dark matter or to make a noticeable contribution to it. On the other hand, for $\eta \gtrsim 1$ the cosmological energy density of MCPs can be quite low, ${\Omega }_X{h}_0^2\approx 0.02$ for scalar MCPs, and ${\Omega }_X{h}_0^2\approx 0.001$ for spin 1/2 fermions. But even the lowest value of ${\Omega }_X{h}_0^2$ is in tension with several existing limits on the MCP abundances and parameters. However, these limits have been derived under some natural or reasonable assumptions on the properties of MCPs. If these assumptions are relaxed, a patch in the mass-charge plot of MCPs may appear, permitting them to be dark matter particles.

    hep-phJ.Exp.Theor.Phys.(2017)·6 citations
15. 15*

    Modulus stabilisation in a backreacted warped geometry model via Goldberger-Wise mechanism

    Ashmita Das🇮🇳 · Tanmoy Paul🇮🇳 · Soumitra SenGupta🇮🇳

    In the context of higher dimensional braneworld scenario, the stabilisation of extra dimensional modulus is an essential requirement for resolving the gauge hierarchy problem in the context of Standard Model of elementary particle Physics. For Randall-Sundrum (RS) warped extra dimensional model, Goldberger and Wise (GW) proposed a much useful mechanism to achieve this using a scalar field in the bulk spacetime ignoring the effects of backreaction of the scalar field on the background metric. In this article we examine the influence of the backreaction of the stabilising field on the stabilisation condition as well as that on the Physics of the extra dimensional modulus namely radion. In particular we obtain the modifications of the mass and the coupling of the radion with the Standard Model (SM) matter fields on the TeV brane due to backreaction effect. Our calculation also brings out an important equivalence between the treatments followed by Csaki et.al. in \cite{kribs} and Goldberger-Wise in \cite{GW1,GW_radion}.

    hep-phgr-qchep-th9 citations
16. 16*

    Impact of the Photon-Initiated process on Z'-boson searches in di-lepton final states at the LHC

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

    We discuss the effect of the Photon Initiated (PI) process on the dilepton channel at the LHC. Adopting various QED PDF sets, we evaluate the contribution produced by two resolved photons which is not included in the Equivalent Photon Approximation (EPA). We compare the PI central value as predicted by the CTEQ, MRST and NNPDF collaborations. With the NNPDF2.3QED set of replicas we also estimate the PDF uncertainties on the PI central value. We show the effect of the inclusion of the PI contribution and its PDF uncertainties on neutral heavy Z'-boson searches. We explore the two scenarios of narrow and broad resonances, including in the analysis the reconstructed Forward-Backward Asymmetry observable, the latter being less affected by systematics effects.

    hep-ph4 citations
17. 17*

    The Breaking $\mu \leftrightarrow \tau$ Symmetry through the ${\mathbf{Q}}_6$ Flavour Group

    J. C. Gómez-Izquierdo🇲🇽 · F. González-Canales🇲🇽 · M. Mondragon🇲🇽

    In a supersymmetric scenario, we study masses and mixings for leptons through the ${\mathbf{Q}}_6$ flavour symmetry. In the simplest case, the ${\mathbf{M}}_{\nu }$ effective neutrino mass matrix, that comes from the type I see-saw mechanism, breaks the $\mu \leftrightarrow \tau$ interchange symmetry. As consequence, the reactor and atmospheric angles deviate from $0^{\circ }$ and $45^{\circ }$, respectively. At first glance, the model might accommodate very well the reactor and atmospheric angles in good agreement with the experimental data.

    hep-phPoS(2016)·0 citations
18. 18*

    Dark Matter Relic Abundance and Light Sterile Neutrinos

    Yi-Lei Tang🇨🇳 · Shou-hua Zhu🇨🇳

    In this paper, we calculate the relic abundance of the dark matter particles when they can annihilate into sterile neutrinos with the mass $\lesssim 100\text{ GeV}$ in a simple model. Unlike the usual standard calculations, the sterile neutrino may fall out of the thermal equilibrium with the thermal bath before the dark matter freezes out. In such a case, if the Yukawa coupling $y_N$ between the Higgs and the sterile neutrino is small, this process gives rise to a larger ${\Omega }_{\text{DM}}{h}^2$ so we need a larger coupling between the dark matter and the sterile neutrino for a correct relic abundance.

    hep-phJHEP(2017)·28 citations
19. 19*

    One loop effects of natural SUSY in third generation fermion production at the ILC

    Yusaku Kouda🇯🇵 · Tadashi Kon🇯🇵 · Yoshimasa Kurihara🇯🇵 · Tadashi Ishikawa🇯🇵 · Masato Jimbo🇯🇵 · Kiyoshi Kato🇯🇵 · Masaaki Kuroda🇯🇵

    Within the framework of the Minimal Supersymmetric Standard Model, we investigate the 1-loop effects of supersymmetric particles on the third-generation fermion-pair production at the ILC. Three sets of the SUSY parameters are proposed which are consistent with the observed Higgs mass, the muon g-2, the Dark Matter abundance and the decay branching ratio of B meson. We discuss on the possibility of discovering the signals consistent with SUSY as well as of experimentally distinguishing the proposed sets of SUSY parameters.

    hep-phPTEP(2017)·6 citations
20. 20*

    Reparametrizing the Polyakov$-$Nambu$-$Jona-Lasinio model

    Abhijit Bhattacharyya🇮🇳 · Sanjay K. Ghosh🇮🇳 · Soumitra Maity🇮🇳 · Sibaji Raha🇮🇳 · Rajarshi Ray🇮🇳 · Kinkar Saha🇮🇳 · Sudipa Upadhaya🇮🇳

    The Polyakov$-$Nambu$-$Jona-Lasinio model has been quite successful in describing various qualitative features of observables for strongly interacting matter, that are measurable in heavy-ion collision experiments. The question still remains on the quantitative uncertainties in the model results. Such an estimation is possible only by contrasting these results with those obtained from first principles using the lattice QCD framework. Recently a variety of lattice QCD data were reported in the realistic continuum limit. Here we make a first attempt at reparametrizing the model so as to reproduce these lattice data. We find excellent quantitative agreement for the equation of state. Certain discrepancies in the charge and strangeness susceptibilities as well as baryon-charge correlation still remain. We discuss their causes and outline possible directions to remove them.

    hep-phhep-latnucl-thPRD(2017)·32 citations
21. 21*

    The $NLO$ production of the $W^{\pm }$ and $Z^0$ vector bosons via hadron collisions in the frameworks of $KMR$ and $MRW$ unintegrated parton distribution functions

    M. Modarres🇮🇷 · M.R. Masouminia🇮🇷 · R. Aminzadeh-Nik🇮🇷 · H. Hosseinkhani🇮🇷 · N. Olanj🇮🇷

    In a series of papers, we have investigated the compatibility of the $Kimber$-$Martin$-$Ryskin$ ($KMR$) and $Martin$-$Ryskin$-$Watt$ ($MRW$) $unintegrated$ parton distribution functions ($UPDF$) as well as the description of the experimental data on the proton structure functions. The present work is a sequel to that survey, via calculation of the transverse momentum distribution of the electro-weak gauge vector bosons in the $k_t$-factorization scheme, by the means of the $KMR$, the $LOMRW$ and the $NLOMRW$ $UPDF$, in the next-to leading order ($NLO$). To this end, we have calculated and aggregated the invariant amplitudes of the corresponding $involved$ diagrams in the $NLO$, and counted the individual contributions in different frameworks. The preparation process for the $UPDF$ utilizes the $PDF$ of $Martin$ et al, $MSTW2008-LO$, $MSTW2008-NLO$, $MMHT2014-LO$ and $MMHT2014-NLO$ as the inputs. Afterwards, the results have been analyzed against each other, as well as the existing experimental data. Our calculation show excellent agreement with the experiment data. It is however interesting to point-out that, the calculation using the $KMR$ framework illustrates a stronger agreement with the experimental data, despite the fact that the $LOMRW$ and the $NLOMRW$ formalisms employ a better theoretical description of the $DGLAP$ evolution equation. This is of course due to the use of the different implementation of the angular ordering constraint in the $KMR$ approach, in which automatically includes the re-summation of $ln(1/x)$, $BFKL$ logarithms, in the $LO$-$DGLAP$ evolution equation.

    hep-phPRD(2016)·19 citations
22. 22*

    Low-lying charmed and charmed-strange baryon states

    Bing Chen🇨🇳 · Ke-Wei Wei🇨🇳 · Xiang Liu🇨🇳 · Takayuki Matsuki🇯🇵

    In this work, we systematically study the mass spectra and strong decays of $1P$ and $2S$ charmed and charmed-strange baryons in the framework of nonrelativistic constituent quark models. With the light quark cluster-heavy quark picture, the masses are simply calculated by a potential model. The strong decays are studied by the Eichten-Hill-Quigg decay formula. Masses and decay properties of the well-established $1S$ and $1P$ states can be reproduced by our method. ${\Sigma }_c(2800{)}^{0,+,++}$ can be assigned as a ${\Sigma }_{c2}(3/2^{-})$ or ${\Sigma }_{c2}(5/2^{-})$ state. We prefer to interpret the signal ${\Sigma }_c(2850{)}^0$ as a $2S(1/2^{+})$ state although at present we cannot thoroughly exclude the possibility that this is the same state as ${\Sigma }_c(2800{)}^0$. ${\Lambda }_c(2765{)}^{+}$ or ${\Sigma }_c(2765{)}^{+}$ could be explained as the ${\Lambda }_c^{+}(2S)$ state or ${\Sigma }_{c1}^{+}(1/2^{-})$ state, respectively. We propose to measure the branching ratio of $\mathcal{B}({\Sigma }_c(2455)\pi )/\mathcal{B}({\Sigma }_c(2520)\pi )$ in future, which may disentangle the puzzle of this state. Our results support ${\Xi }_c(2980{)}^{0,+}$ as the first radial excited state of ${\Xi }_c(2470{)}^{0,+}$ with $J^P=1/2^{+}$. The assignment of ${\Xi }_c(2930{)}^0$ is analogous to ${\Sigma }_c(2800{)}^{0,+,++}$, \emph{i.e.}, a ${\Xi }_{c2}^{\prime }(3/2^{-})$ or ${\Xi }_{c2}^{\prime }(5/2^{-})$ state. In addition, we predict some typical ratios among partial decay widths, which are valuable for experimental search for these missing charmed and charmed-strange baryons.

    hep-phhep-exEPJC(2017)·116 citations
23. 23*

    CTEQ-TEA parton distribution functions and HERA Run I and II combined data

    Tie-Jiun Hou🇺🇸 · Sayipjamal Dulat🇨🇳 · Jun Gao🇺🇸 · Marco Guzzi🇬🇧 · Joey Huston🇺🇸 · Pavel Nadolsky🇺🇸 · Jon Pumplin🇺🇸 · Carl Schmidt🇺🇸 · Daniel Stump🇺🇸 · C.-P. Yuan🇺🇸

    We analyze the impact of the recent HERA run I+II combination of inclusive deep inelastic scattering cross-section data on the CT14 global analysis of PDFs. New PDFs at NLO and NNLO, called CT14${}_{\text{HERA2}}$, are obtained by a refit of the CT14 data ensembles, in which the HERA run I combined measurements are replaced by the new HERA run I+II combination. The CT14 functional parametrization of PDFs is flexible enough to allow good descriptions of different flavor combinations, so we use the same parametrization for CT14${}_{\text{HERA2}}$ but with an additional shape parameter for describing the strange quark PDF. We find that the HERA I+II data can be fit reasonably well, and both CT14 and CT14${}_{\text{HERA2}}$ PDFs can describe equally well the non-HERA data included in our global analysis. Because the CT14 and CT14${}_{\text{HERA2}}$ PDFs agree well within the PDF errors, we continue to recommend CT14 PDFs for the analysis of LHC Run 2 experiments.

    hep-phPRD(2017)·53 citations
24. 24*

    Baryogenesis via leptonic CP-violating phase transition

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

    We propose a new mechanism to generate a lepton asymmetry based on the vacuum CP-violating phase transition (CPPT). This approach differs from classical thermal leptogenesis as a specific seesaw model, and its UV completion, need not be specified. The lepton asymmetry is generated via the dynamically realised coupling of the Weinberg operator during the phase transition. This mechanism provides a connection with low-energy neutrino observables.

    hep-phastro-ph.COhep-exPLB(2018)·22 citations
25. 25*

    Interface Effect in QCD Phase Transitions via Dyson-Schwinger Equation Approach

    Fei Gao🇨🇳 · Yu-xin Liu🇨🇳

    With the chiral susceptibility criterion we obtain the phase diagram of strong-interaction matter in terms of temperature and chemical potential in the framework of Dyson-Schwinger equations (DSEs) of QCD.After calculating the pressure and some other thermodynamic properties of the matter in the DSE method, we get the phase diagram in terms of temperature and baryon number density. We also obtain the interface tension and the interface entropy density to describe the inhomogeneity of the two phases in the coexistence region of the first order phase transition. After including the interface effect, we find that the total entropy density of the system increases in both the deconfinement (dynamical chiral symmetry restoration) and the hadronization (dynamical chiral symmetry breaking) processes of the first order phase transitions and thus solve the entropy puzzle in the hadronization process.

    hep-phPRD(2016)·52 citations
26. 26*

    Modelling glueballs

    Francesco Giacosa🇩🇪

    Glueballs are predicted in various theoretical approaches of QCD (most notably lattice QCD), but their experimental verification is still missing. In the low-energy sector some promising candidate for the scalar glueball exist, and some (less clear) candidates for the tensor and pseudoscalar glueballs were also proposed. Yet, for heavier gluonic states there is much work to be done both from the experimental and theoretical points of view. In these proceedings, we briefly review the current status of research of glueballs and discuss future developments.

    hep-phEPJ Web Conf.(2016)·8 citations
27. 27*

    Chiral study of the $a_0(980)$ resonance and $\pi \eta$ scattering phase shifts in light of a recent lattice simulation

    Zhi-Hui Guo🇨🇳 · Liuming Liu🇩🇪 · Ulf-G. Meißner🇩🇪 · J. A. Oller🇪🇸 · A. Rusetsky🇩🇪

    We investigate the $a_0(980)$ resonance within chiral effective field theory through a three-coupled-channel analysis, namely $\pi \eta$, $K\bar{K}$ and $\pi {\eta }^{\prime }$. A global fit to recent lattice finite-volume energy levels from $\pi \eta$ scattering and relevant experimental data on a $\pi \eta$ event distribution and the $\gamma \gamma \to \pi \eta$ cross section is performed. Both the leading and next-to-leading-order analyses lead to similar and successful descriptions of the finite-volume energy levels and the experimental data. However, these two different analyses yield different $\pi \eta$ scattering phase shifts for the physical masses for the $\pi ,K,\eta$ and ${\eta }^{\prime }$ mesons. The inelasticities, the pole positions in the complex energy plane and their residues are calculated both for unphysical and physical meson masses.

    hep-phhep-exhep-latnucl-thPRD(2017)·68 citations
28. 28*

    TeV- and MeV-physics out of an $S{U}_L(2)\times U_R(1{)}_J\times U(1{)}_K$ model

    M. J. Neves🇧🇷 · J. A. Helaÿel-Neto🇧🇷

    The standard electroweak interaction is here re-assessed to accommodate two different situations in Particle Physics. The first one is a $Z^{\prime }$-model at the TeV-scale physics. The second one tackles the recent discussion of a possible fifth force mediated by a $17$-MeV X-boson associated with an electron-positron emission in the transition of an excited 8-Beryllium to its ground state. The anomaly-free model that provides these two scenarios is based on an $S{U}_L(2)\times U_R(1{)}_J\times U(1{)}_K$-symmetry. It yields a new massive neutral boson, an exotic massive neutral fermion, right-neutrinos and an additional neutral Higgs particle, which stems from a supplementary Higgs field, introduced along with the usual Higgs doublet responsible for the electroweak breaking and the masses of $W^{\pm }$ and $Z^0$. Yukawa interactions of the two scalars generate the masses of the Standard Model leptons, neutrinos and a new exotic fermion of the model. The vacuum expectation values of the Higgses fix up two independent energy scales. One of them is the well-confirmed electroweak scale, $246\text{mbox}GeV$, whereas the other one is set up by adopting an experimental estimate for the $Z^{\prime }$-mass.

    hep-phAnnalen Phys.(2018)·9 citations
29. 29*

    Light-like Scattering in Quantum Gravity

    N. E. J. Bjerrum-Bohr🇩🇰 · John F. Donoghue🇺🇸 · Barry R. Holstein🇺🇸 · Ludovic Plante🇫🇷 · Pierre Vanhove🇫🇷

    We consider scattering in quantum gravity and derive long-range classical and quantum contributions to the scattering of light-like bosons and fermions (spin-0, spin-1/2, spin-1) from an external massive scalar field, such as the Sun or a black hole. This is achieved by treating general relativity as an effective field theory and identifying the non-analytic pieces of the one-loop gravitational scattering amplitude. It is emphasized throughout the paper how modern amplitude techniques, involving spinor-helicity variables, unitarity, and squaring relations in gravity enable much simplified computations. We directly verify, as predicted by general relativity, that all classical effects in our computation are universal (in the context of matter type and statistics). Using an eikonal procedure we confirm the post-Newtonian general relativity correction for light-like bending around large stellar objects. We also comment on treating effects from quantum hbar dependent terms using the same eikonal method.

    ↳ hep-thgr-qchep-phJHEP(2016)·143 citations
30. 30*

    Estimation of the chiral magnetic effect considering the magnetic field response of the QGP medium

    Sheng-Qin Feng · Xin Ai · Lei Pei · Fei Sun · Yang Zhong · Zhong-Bao Yin

    The magnetic field plays a major role in the searching of the chiral magnetic effect in relativistic heavy-ion collisions. If the lifetime of the magnetic field is too short, as expected by simulations of the field in the vacuum, the chiral magnetic effect will be largely suppressed. However, the lifetime of the magnetic field will become longer when the QGP medium response is considered. We give an estimate of the effect, especially considering the magnetic field response of the QGP medium, and compare it with the experimental results of background-subtracted correlator $H$ at RHIC and LHC energies. The results show that our method explains better for the experimental results at the top RHIC energy than that of the LHC energy.

    ↳ nucl-thhep-phCPC(2018)·12 citations
31. 31*

    A differential operator for integrating one-loop scattering equations

    Gang Chen🇨🇳 · Yeuk-Kwan E. Cheung🇨🇳 · Tianheng Wang🇨🇳 · Feng Xu🇨🇳

    We propose a differential operator for computing the residues associated with a class of meromorphic $n$-forms that frequently appear in the Cachazo-He-Yuan form of the scattering amplitudes. This differential operator is conjectured to be uniquely determined by the local duality theorem and the intersection number of the divisors in the $n$-form. We use the operator to evaluate the tree-level amplitude of ${\varphi }^3$ theory and the one-loop integrand of Yang-Mills theory from their CHY forms. The method can reduce the complexity of the calculation. In addition, the expression for the 1-loop four-point Yang-Mills integrand obtained in our approach has a clear correspondence with the Q-cut results.

    ↳ hep-thhep-phmath-phmath.MPJHEP(2017)·17 citations
32. 32*

    Rescuing the nonjet (NJ) azimuth quadrupole from the flow narrative

    Thomas A. Trainor🇺🇸

    According to the flow narrative commonly applied to high-energy nuclear collisions a cylindrical-quadrupole component of 1D azimuth angular correlations is conventionally denoted by quantity $v_2$ and interpreted to represent elliptic flow. Jet angular correlations may also contribute to $v_2$ data as "nonflow" depending on the method used to calculate $v_2$, but 2D graphical methods are available to insure accurate separation. The nonjet (NJ) quadrupole has various properties inconsistent with a flow interpretation, including the observation that NJ quadrupole centrality variation in A-A collisions has no relation to strongly-varying jet modification ("jet quenching") in those collisions commonly attributed to jet interaction with a flowing dense medium. In this presentation I describe isolation of quadrupole spectra from pt-differential $v_2(p_t)$ data from the RHIC and LHC. I demonstrate that quadrupole spectra have characteristics very different from the single-particle spectra for most hadrons, that quadrupole spectra indicate a common boosted hadron source for a small minority of hadrons that "carry" the NJ quadrupole structure, that the narrow source-boost distribution is characteristic of an expanding thin cylindrical shell (strongly contradicting hydro descriptions), and that in the boost frame a single universal quadrupole spectrum (Lévy distribution) on transverse mass $m_t$ accurately describes data for several hadron species scaled according to their statistical-model abundances. The quadrupole spectrum shape changes very little from RHIC to LHC energies. Taken in combination those characteristics strongly suggest a unique {\em nonflow} (and nonjet) QCD mechanism for the NJ quadrupole conventionally represented by $v_2$.

    ↳ nucl-thhep-phEPJ Web Conf.(2017)·0 citations
33. 33*

    Sterile Neutrinos: An Introduction to Experiments

    J.M. Conrad🇺🇸 · M.H. Shaevitz🇺🇸

    This paper is written as one chapter in a collection of essays on neutrino physics for beginning graduate students. The text presents important experimental methods and issues for those interested in searches for sterile neutrinos. Other essays in the collection, written by other authors, will cover introduction to neutrinos in the Standard Model, a description of the theory, and discussion of details of detectors, thus these aspects are not covered here. However, beyond these points, this represents a self-contained tutorial on experimental studies of sterile neutrino oscillations, covering such issues as signals vs. limits, designing experiments, and performing and interpreting global fits to the oscillation data.

    ↳ hep-exhep-phAdv.Ser.Direct.High Energy Phys.(2018)·34 citations
34. 34*

    Lamb shift in muonic ions of lithium, beryllium and boron

    A.A. Krutov🇷🇺 · A.P. Martynenko🇷🇺 · F.A. Martynenko🇷🇺 · O.S. Sukhorukova (Samara University)🇷🇺

    We present a precise calculation of the Lamb shift $(2P_{1/2}-2S_{1/2})$ in muonic ions $({\mu }_3^{6}Li{)}^{2+},({\mu }_3^{7}Li{)}^{2+}$, $({\mu }_4^{9}Be{)}^{3+},({\mu }_4^{10}Be{)}^{3+}$, $({\mu }_5^{10}B{)}^{4+},({\mu }_5^{11}B{)}^{4+}$. The contributions of orders ${\alpha }^3÷{\alpha }^6$ to the vacuum polarization, nuclear structure and recoil, relativistic effects are taken into account. Our numerical results are consistent with previous calculations and improve them due to account of new corrections. The obtained results can be used for the comparison with future experimental data, and extraction more accurate values of nuclear charge radii.

    ↳ physics.atom-phhep-phPRA(2016)·29 citations
35. 35*

    Identifying Ultrahigh-Energy Cosmic-Ray Accelerators with Future Ultrahigh-Energy Neutrino Detectors

    Ke Fang🇺🇸 · Kumiko Kotera🇫🇷 · M. Coleman Miller🇺🇸 · Kohta Murase🇺🇸 · Foteini Oikonomou🇺🇸

    The detection of ultrahigh-energy (UHE) neutrino sources would contribute significantly to solving the decades-old mystery of the origin of the highest-energy cosmic rays. We investigate the ability of a future UHE neutrino detector to identify the brightest neutrino point sources, by exploring the parameter space of the total number of observed events and the angular resolution of the detector. The favored parameter region can be translated to requirements for the effective area, sky coverage and angular resolution of future detectors, for a given source number density and evolution history. Moreover, by studying the typical distance to sources that are expected to emit more than one event for a given diffuse neutrino flux, we find that a significant fraction of the identifiable UHE neutrino sources may be located in the nearby Universe if the source number density is above $\sim 10^{-6}\mathrm{Mp}{\mathrm{c}}^{-3}$. If sources are powerful and rare enough, as predicted in blazar scenarios, they can first be detected at distant locations. Our result also suggests that if UHE cosmic-ray accelerators are neither beamed nor transients, it will be possible to associate the detected UHE neutrino sources with nearby UHE cosmic-ray and gamma-ray sources, and that they may also be observed using other messengers, including ones with limited horizons such as TeV gamma rays, UHE gamma rays and cosmic rays. We find that for a $\gtrsim 5\sigma$ detection of UHE neutrino sources with a uniform density, $n_s\sim {10}^{-7}-{10}^{-5}{\mathrm{Mpc}}^{-3}$, at least $\sim 100-1000$ events and sub-degree angular resolution are needed, and the results depend on the source evolution model.

    ↳ astro-ph.HEastro-ph.IMhep-phJCAP(2016)·40 citations
36. 36*

    Equivalence and/or quantum duality of the non/supersymmetric noncommutative field theories related by the theta-exact Seiberg-Witten map

    Raul Horvat🇭🇷 · Carmelo P. Martin🇪🇸 · Josip Trampetic🇭🇷 · Jiangyang You🇭🇷

    In this article we expound a discovery of the quantum equivalence/duality of U(N) noncommutative quantum field theories (NC QFT) related by the theta-exact Seiberg-Witten (SW) maps and at all orders in the perturbation theory with respect to the coupling constant. We show that this proof holds for Super Yang-Mills (SYM) theories with N=0,1,2,4$ supersymmetry. In short, Seiberg-Witten map does commute with the quantization of the U(N) NCQFT independently, with or without supersymmetry.

    ↳ hep-thhep-ph2 citations
37. 37*

    Nuclear Effects in the Deuteron and Global PDF Fits

    S.I. Alekhin🇷🇺 · S.A. Kulagin🇷🇺 · R. Petti🇺🇸

    We present a detailed study of nuclear corrections in the deuteron (D) from an analysis of data from charged-lepton deep-inelastic scattering (DIS) off proton and D, as well as from dimuon pair production in pp and pD collisions and $W^{\pm }$ and the $Z$ boson production at pp (p$\bar{\mathrm{p}}$) colliders. In particular, we discuss the determination of the off-shell function describing the modification of parton distributions (PDF) in bound nucleons in the context of global PDF fits. Our results are consistent with the ones obtained earlier from the study of the ratios of DIS structure functions $F_2^A/F_2^D$ in nuclei with $A\ge 4$, confirming the universality of the off-shell function. We also discuss the sensitivity to various models of the deuteron wave function and the impact of nuclear corrections on the determination of the $d$ quark distribution.

    ↳ nucl-thhep-exhep-phPoS(2016)·4 citations
38. 38*

    Mass spectra and Regge trajectories of ${\Lambda }_c^{+}$, ${\Sigma }_c^0$, ${\Xi }_c^0$ and ${\Omega }_c^0$ Baryons

    Zalak Shah🇮🇳 · Kaushal Thakkar🇮🇳 · Ajay Kumar Rai🇮🇳 · P. C. Vinodkumar🇮🇳

    We calculate the mass spectra of the singly charmed baryons (${\Lambda }_c^{+}$, ${\Sigma }_c^0$, ${\Xi }_c^0$ and ${\Omega }_c^0$) using Hypercentral constituent quark model(hCQM). The hyper color coloumb plus linear potential is used to calculate the masses of positive(upto $J^p={\frac{7}{2}}^{+}$) and negative parity(upto $J^p={\frac{9}{2}}^{-}$) excited states. The spin-spin, spin-orbital and tensor interaction terms are also incorporated for mass spectra. We have compared our results with other theoretical predictions and Lattice QCD for each baryons. Moreover, the known experimental results are also reasonably closed to our predicted masses. By using the radial and orbital excitation, we construct Regge trajectories for the baryons in (n,$M^2$) plane and find their slopes and intercepts. The other properties like, magnetic moments, radiative transitions and radiative decay widths of these baryons are also calculated successfully.

    ↳ nucl-thhep-phCPC(2016)·114 citations
39. 39*

    Voigt transformations in retrospect: missed opportunities?

    Olga Chashchina🇫🇷 · Natalya Dudisheva🇷🇺 · Zurab Silagadze🇷🇺

    The teaching of modern physics often uses the history of physics as a didactic tool. However, as in this process the history of physics is not something studied but used, there is a danger that the history itself will be distorted in, as Butterfield calls it, a "Whiggish" way, when the present becomes the measure of the past. It is not surprising that reading today a paper written more than a hundred years ago, we can extract much more of it than was actually thought or dreamed by the author himself. We demonstrate this Whiggish approach on the example of Woldemar Voigt's 1887 paper. From the modern perspective, it may appear that this paper opens a way to both the special relativity and to its anisotropic Finslerian generalization which came into the focus only recently, in relation with the Cohen and Glashow's very special relativity proposal. With a little imagination, one can connect Voigt's paper to the notorious Einstein-Poincare priority dispute, which we believe is a Whiggish late time artifact. We use the related historical circumstances to give a broader view on special relativity, than it is usually anticipated.

    ↳ physics.hist-phhep-phhep-thAnnales Fond.Broglie(2019)·2 citations
40. 40*

    Chiral density wave versus pion condensation in the 1+1 dimensional NJL model

    Prabal Adhikari🇺🇸 · Jens O. Andersen🇳🇴

    In this paper, we study the possibility of an inhomogeneous quark condensate in the 1+1 dimensional Nambu-Jona-Lasinio model in the large-$N_c$ limit at finite temperature $T$ and quark chemical potential $\mu$ using dimensional regularization. The phase diagram in the $\mu$--$T$ plane is mapped out. At zero temperature, an inhomogeneous phase with a chiral-density wave exists for all values of $\mu >{\mu }_c$. Performing a Ginzburg-Landau analysis, we show that in the chiral limit, the critical point and the Lifschitz point coincide. We also consider the competition between a chiral-density wave and a constant pion condensate at finite isospin chemical potential ${\mu }_I$. The phase diagram in the ${\mu }_I$--$\mu$ plane is mapped out and shows a rich phase structure.

    ↳ hep-thhep-phPRD(2017)·13 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.