Tue·Sep 22, 2015Tuesday·September 22, 2015

1. 01*

   Little Flavor and U(2) Family Symmetry

   Dorota M. Grabowska🇺🇸 · David B. Kaplan🇺🇸

   We examine an effective field theory inspired by Little Flavor that demonstrates a new paradigm for generating quark and lepton masses in which the scale of new flavor physics can be at the few TeV level, and new $Z^{\prime }$ and $W^{\prime }$ bosons are predicted. The model possesses an approximate $U(2{)}^2$ vector symmetry, not the full approximate $U(2{)}^5$ chiral symmetry of the Standard Model or Minimal Flavor Violation models, yet flavor changing neutral currents are sufficiently suppressed. Additionally, lepton flavor violating processes, such as $\mu \to 3e$, lie naturally just below experimental bounds and the down quark mass can be radiatively generated.

   hep-ph3 citations
2. 02*

   Minimal nonabelian model of atomic dark matter

   Jeremie Choquette🇨🇦 · James M. Cline🇨🇦

   A dark sector resembling the standard model, where the abundance of matter is explained by baryon and lepton asymmetries, and stable constituents bind to form atoms, is a theoretically appealing possibility. We show that a minimal model with a hidden SU(2) gauge symmetry broken to U(1), with a Dirac fermion doublet, suffices to realize this scenario. Supplemented with a dark Higgs doublet that gets no VEV, we readily achieve the dark matter asymmetry through leptogenesis. The model can simultaneously have three portals to the standard model, through the Higgs, nonabelian kinetic mixing, and the heavy neutrino, with interesting phenomenology for direct and collider searches, as well as cosmologically relevant DM self-interactions. Exotic bound states consisting of two fermions and a doubly-charged vector boson can exist in one phase of the theory.

   hep-phastro-ph.COPRD(2015)·33 citations
3. 03*

   Less-simplified models of dark matter for direct detection and the LHC

   Arghya Choudhury🇮🇳 · Kamila Kowalska🇵🇱 · Leszek Roszkowski🇵🇱 · Enrico Maria Sessolo🇵🇱 · Andrew J. Williams🇵🇱

   We construct models of dark matter with suppressed spin-independent scattering cross section utilizing the existing simplified model framework. Even simple combinations of simplified models can exhibit interference effects that cause the tree level contribution to the scattering cross section to vanish, thus demonstrating that direct detection limits on simplified models are not robust when embedded in a more complicated and realistic framework. In general for fermionic WIMP masses >10 GeV direct detection limits on the spin-independent scattering cross section are much stronger than those coming from the LHC. However these model combinations, which we call less-simplified models, represent situations where LHC searches become more competitive than direct detection experiments even for moderate dark matter mass. We show that a complementary use of several searches at the LHC can strongly constrain the direct detection blind spots by setting limits on the coupling constants and mediators' mass. We derive the strongest limits for combinations of vector + scalar, vector + "squark", and "squark" + scalar mediator, and present the corresponding projections for the LHC 14 TeV for a number of searches: mono-jet, jets + missing energy, and searches for heavy vector resonances.

   hep-phastro-ph.COhep-exJHEP(2016)·30 citations
4. 04*

   Higher-Order QCD Predictions for Dark Matter Production in Mono-$Z$ Searches at the LHC

   Matthias Neubert🇩🇪 · Jian Wang🇩🇪 · Cen Zhang🇺🇸

   We present theoretical predictions for mono-$Z$ production in the search for dark matter in Run-II at the LHC, including next-to-leading order QCD corrections and parton-shower effects. We consider generic simplified models with vector and scalar $s$-channel mediators. The calculation is performed by implementing the simplified models in the FeynRules/MadGraph5_aMC@NLO framework, which allows us to include higher-order QCD corrections and parton-shower effects in an automated way. We find that these corrections are sizeable and help to reduce the theoretical uncertainties. We also investigate the discovery potential in several benchmark scenarios in the 13 TeV run at the LHC.

   hep-phJHEP(2016)·44 citations
5. 05*

   Inflation due to a non-minimal coupling of singlet scalars in the radiative seesaw model

   Romy H. S. Budhi🇮🇩 · Shoichi Kashiwase🇯🇵 · Daijiro Suematsu🇯🇵

   The radiative neutrino mass model with inert doublet dark matter is a promising model for the present experimental issues which cannot be explained within the standard model. We study an extension of this model focusing on cosmological features brought about from the scalar sector. Inflation due to singlet scalars with hierarchical non-minimal couplings with the Ricci scalar may give a favorable solution for both neutrino masses and baryon number asymmetry in the Universe.

   hep-phastro-ph.COPRD(2016)·15 citations
6. 06*

   Higgs boson production in association with b jets in the POWHEG BOX

   Barbara Jager (Tubingen U.)🇩🇪 · Laura Reina (Florida State U.)🇺🇸 · Doreen Wackeroth (SUNY, Buffalo)🇺🇸

   The hadronic production of a Higgs boson (H) in association with b jets will play an important role in investigating the Higgs-boson couplings to Standard Model particles during Run II of the CERN Large Hadron Collider, and could in particular reveal the presence of anomalies in the assumed hierarchy of Yukawa couplings to the third-generation quarks. A very high degree of accuracy in the theoretical description of this process is crucial to implement the rich physics program that could lead to either direct or indirect evidence of new physics from Higgs-boson measurements. Aiming for accuracy in the theoretical modeling of H+b-jet production, we have interfaced the analytic Next-to-Leading-Order QCD calculation of H-bottom-antibottom production with parton-shower Monte Carlo event generators in the POWHEG BOX framework. In this paper we describe the most relevant aspects of the implementation and present results for the production of H+1 b jet, H+2 b jets, and $H$ with no tagged b jets, in the form of kinematic distributions of the Higgs boson, of the b jets, and of the non-b jets, at the 13 TeV Large Hadron Collider. The corresponding code is part of the public release of the POWHEG BOX.

   hep-phPRD(2016)·44 citations
7. 07*

   Dileptons in a coarse-grained transport approach

   H. van Hees🇩🇪 · S. Endres🇩🇪 · J. Weil🇩🇪 · M. Bleicher🇩🇪

   We calculate dilepton spectra in heavy-ion collisions using a coarse-graining approach to the simulation of the created medium with the UrQMD transport model. This enables the use of dilepton-production rates evaluated in equilibrium quantum-field theory at finite temperatures and chemical potentials.

   hep-phnucl-thJ.Phys.Conf.Ser.(2016)·0 citations
8. 08*

   Perturbative study of Yang-Mills theory in the infrared

   Fabio Siringo🇮🇹

   Pure Yang-Mills SU(N) theory is studied in four dimensional space and Landau gauge by a double perturbative expansion based on a massive free-particle propagator. By dimensional regularization, all diverging mass terms cancel exactly in the double expansion, without the need to include mass counterterms that would spoil the symmetry of the original Lagrangian. The emerging perturbation theory is safe in the infrared and shares the same behaviour of the standard perturbation theory in the UV. At one-loop, gluon and ghost propagators are found in excellent agreement with the data of lattice simulations and an infrared-safe running coupling is derived. A natural scale m=0.6-0.7 GeV is extracted from the data for N=3.

   hep-phhep-lathep-th27 citations
9. 09*

   q-deformed statistics and the role of a light fermionic dark matter in the supernova SN1987A cooling

   Atanu Guha🇮🇳 · Selvaganapathy.J · Prasanta Kumar Das🇮🇳

   Light dark matter($\simeq 1-30\mathrm{MeV}$) particles pair produced in electron-positron annihilation $e^{-}{e}^{+}\stackrel{\gamma }{⟶}\chi \bar{\chi }$ inside the supernova core can take away the energy released in the supernova SN1987A explosion. Working within the formalism of $q$-deformed statistics (with the average value of the supernovae core temperature(fluctuating) being $T_{SN}=30\mathrm{MeV}$) and using the Raffelt's criterion on the emissivity for any new channel $\dot{\epsilon }(e^{+}{e}^{-}\to \chi \overline{\chi })\le 10^{19}erg{g}^{-1}{s}^{-1}$, we find that as the deformation parameter $q$ changes from $1.0$ (undeformed scenario) to $1.1$(deformed scenario), the lower bound on the scale $\Lambda$ of the dark matter effective theory varies from $3.3\times 10^6$ TeV to $3.2\times 10^7$ TeV for a dark matter fermion of mass $m_{\chi }=30\mathrm{MeV}$. Using the optical depth criteria on the free streaming of the dark matter fermion, we find the lower bound on $\Lambda \sim 10^8\mathrm{TeV}$ for $m_{\chi }=30\mathrm{MeV}$. In a scenerio,where the dark matter fermions are pair produced in the outermost sector of the supernova core (with radius $0.9R_c\le r\le R_c$, $R_c(=10\mathrm{km})$ being the supernova core radius or the radius of proto-neutron star), we find that the bound on $\Lambda$ ($\sim 3\times 10^7$ TeV)obtained from SN cooling criteria (Raffelt's criteria) is comparable with the bound obtained from free streaming (optical depth criterion) for light fermion dark matter of mass $m_{\chi }=10-30$ MeV.

   hep-phastro-ph.HEPRD(2017)·22 citations
10. 10*

    QCD factorization for high $p_T$ heavy quarkonium production

    Yan-Qing Ma🇨🇳 · Jian-Wei Qiu🇺🇸 · George Sterman🇺🇸 · Hong Zhang🇺🇸

    In this talk, we present the QCD factorization formula for heavy quarkonium production at large $p_T$ with factorized leading-power and next-to-leading power contributions in the $1/p_T$ expansion. We show that the leading order analytical calculations in this QCD factorization approach can reproduce effectively the full next-to-leading order numerical results derived using non-relativistic QCD (NRQCD) factorization formalism. We demonstrate that the next-to-leading power contributions are crucial to the description of the channels that are the most relevant for the rate as well as polarization of $J/\psi$ production at current collider energies.

    hep-ph3 citations
11. 11*

    One loop effective nonlinear Lagrangian with a light H-boson

    K. Kanshin🇮🇹

    We study one loop structure of the scalar sector of non-linear electroweak chiral Lagrangian (EWChL) with a light (composite) H-boson up to four derivatives. First, we introduce relevant Lagrangian terms in general parametrization of would-be Goldstone modes, taking into account potential and finite mass of the scalar. Then we compute 1-, 2-, 3- and 4-point functions and perform complete off-shell renormalization of the processes considered. On the way we found new divergencies involving also the H-boson which cannot be absorbed by the parameters of chiral invariant Lagrangian. We have demonstrated explicitly how these divergencies can be removed by field redefinition, and therefore proved that they are non-physical and give no contribution to the on-shell amplitudes. As a physical result renormalization group equations are derived to be used for future H-boson data analyses.

    hep-ph1 citation
12. 12*

    Effective Field Theory of Integrating out Sfermions in the MSSM: Complete One-Loop Analysis

    Ran Huo🇯🇵

    We apply the covariant derivative expansion of the Coleman-Weinberg potential to the sfermion sector in the minimal supersymmetric standard model, matching it to the relevant dimension-6 operators in the standard model effective field theory at one-loop level. Emphasis is paid to nondegenerate large soft supersymmetry breaking mass squares, and the most general analytical Wilson coefficients are obtained for all pure bosonic dimension-6 operators. In addition to the non-logarithmic contributions, they generally have another logarithmic contributions. Various numerical results are shown, in particular the constraints in the large $X_t$ branch reproducing the $125$~GeV Higgs mass can be pushed to high values to almost completely probe the low stop mass region at the future FCC-ee experiment, even given the Higgs mass calculation uncertainty.

    hep-phPRD(2018)·44 citations
13. 13*

    Discovering sterile Neutrinos ligther than $M_W$ at the LHC

    Claudio O. Dib🇨🇱 · Choong Sun Kim🇰🇷

    We study the purely leptonic $W$ decays $W^{+}\to e^{+}{\mu }^{-}{e}^{+}{\nu }_e$ and $W^{+}\to e^{+}{e}^{+}{\mu }^{-}{\bar{\nu }}_{\mu }$ (or their charge conjugates) produced at the LHC, induced by sterile neutrinos with mass below $M_W$ in the intermediate state. While the first mode is induced by both Dirac or Majorana neutrinos, the second mode is induced only by Majorana neutrinos, as it violates lepton number. We find that, even when the final (anti-)neutrino goes undetected, one could distinguish between these two processes, thus distinguishing the Dirac or Majorana character of the sterile neutrinos, by studying the muon spectrum in the decays.

    hep-phPRD(2015)·62 citations
14. 14*

    A purely quark Lagrangian from QCD

    Amir H. Fariborz🇺🇸 · Renata Jora🇷🇴

    We present a method for determining a purely quark Lagrangian by mocking up the QCD partition function for large gauge couplings $g$. The resulting effective theory displays all the symmetries of low energy QCD and can be potentially used to explore hadron properties.

    hep-phRom.Rep.Phys.(2017)·1 citation
15. 15*

    Exotic Hadrons and Underlying Z_{2,3} Symmetries

    Adil Belhaj🇲🇦 · Salah Eddine Ennadifi🇲🇦 · Moulay Brahim Sedra🇲🇦

    The recent observation of higher quark combinations, tetraquarks and pentaquarks, is a strong indication of more exotic hadrons. Using Z_{2} and Z_{3} symmetries and standard model data, a general quark combination producing new hadronic states is proposed in terms of polygon geometries according to the Dynkin diagrams of \widehat{A}_{n} affine Lie algebras. It has been shown that Z_{\mathbf{2,3}} invariance is crucial in the determination of the mesonic or the baryonic nature of these states. The hexagonal geometry is considered in some details producing both mesonic and baryonic states. A general class of this family is also presented.

    hep-phhep-th0 citations
16. 16*

    Strong decay constants of heavy tensor mesons in light cone QCD sum rules

    H. A. Alhendi🇸🇦 · T. M. Aliev🇹🇷 · M. Savcı🇹🇷

    Strong decay constants of the heavy tensor to heavy pseudoscalar (vector) and light pseudoscalar mesons are estimated within the light cone QCD sum rules. It is obtained that the values of these coupling constants are very strongly dependent on the choice of the Lorentz structure. Moreover, using these strong coupling constants the corresponding decay widths are calculated.

    hep-phJHEP(2016)·14 citations
17. 17*

    Unitarity bound in the most general two Higgs doublet model

    Shinya Kanemura🇯🇵 · Kei Yagyu🇬🇧

    We investigate unitarity bounds in the most general two Higgs doublet model without a discrete $Z_2$ symmetry nor CP conservation. S-wave amplitudes for two-body elastic scatterings of Nambu-Goldstone bosons and physical Higgs bosons are calculated at high energies for all possible initial and final states (14 neutral, 8 singly-charged and 3 doubly-charged states). We obtain analytic formulae for the block-diagonalized scattering matrix by the classification of the two body scattering states using the conserved quantum numbers at high energies. Imposing the condition of perturbative unitarity to the eigenvalues of the scattering matrix, constraints on the model parameters can be obtained. We apply our results to constrain the mass range of the next--to--lightest Higgs state in the model.

    hep-phPLB(2015)·140 citations
18. 18*

    Maximal CP Violation in Flavor Neutrino Masses

    Teruyuki Kitabayashi🇯🇵 · Masaki Yasuè🇯🇵

    Since flavor neutrino masses $M_{\mu \mu ,\tau \tau ,\mu \tau }$ can be expressed in terms of $M_{ee,e\mu ,e\tau }$, mutual dependence among $M_{\mu \mu ,\tau \tau ,\mu \tau }$ is derived by imposing some constraints on $M_{ee,e\mu ,e\tau }$. For appropriately imposed constraints on $M_{ee,e\mu ,e\tau }$, we show a texture of neutrino mass matrix giving rise to maximal CP violation. When the atmospheric neutrino mixing is also maximal, we discuss various specific textures of neutrino mass matrices including the texture with $M_{\tau \tau }=M_{\mu \mu }^{\ast }$ derived as the simplest solution to the constraint of $M_{\tau \tau }-M_{\mu \mu }$=imaginary, which is required by the constraint of $M_{e\mu }\cos {\theta }_{23}-M_{e\tau }\sin {\theta }_{23}$=real for $\cos 2{\theta }_{23}=0$. It is found that Majorana CP violation depends on the phase of $M_{ee}$.

    hep-phInt.J.Mod.Phys.A(2016)·16 citations
19. 19*

    The $S$-wave resonance contributions to the three-body decays $B_{(s)}^0\to {\eta }_c{f}_0(X)\to {\eta }_c{\pi }^{+}{\pi }^{-}$ in perturbative QCD approach

    Ya Li🇨🇳 · Ai-Jun Ma🇨🇳 · Wen-Fei Wang🇨🇳 · Zhen-Jun Xiao🇨🇳

    In this paper, we study the three-body decays $B^0/B_s^0\to {\eta }_c{f}_0(X)\to {\eta }_c{\pi }^{+}{\pi }^{-}$ by employing the perturbative QCD (PQCD) factorization approach. We evaluate the $S$-wave resonance contributions by using the two-pion distribution amplitude ${\Phi }_{\pi \pi }^{\mathrm{S}}$. The Breit-Wigner formula for the $f_0(500)$, $f_0(1500)$, and $f_0(1790)$ resonances and the Flatté model for the $f_0(980)$ resonance are adopted to parameterize the time-like scalar form factors $F_s({\omega }^2)$. We also use the D.~V.~Bugg model to parameterize the $f_0(500)$ and compare the relevant theoretical predictions from different models. We found the following results: (a) the PQCD predictions for the branching ratios are $\mathcal{B}(B^0\to {\eta }_c{f}_0(500)[{\pi }^{+}{\pi }^{-}])=\left(1.53_{-0.35}^{+0.76}\right)\times 10^{-6}$ for Breit-Wigner model and $\mathcal{B}(B^0\to {\eta }_c{f}_0(500)[{\pi }^{+}{\pi }^{-}])=\left(2.31_{-0.48}^{+0.96}\right)\times 10^{-6}$ for D.~V.~Bugg model; (b) $\mathcal{B}(B_s\to {\eta }_c{f}_0(X)[{\pi }^{+}{\pi }^{-}])=\left(5.02_{-1.08}^{+1.49}\right)\times 10^{-5}$ when the contributions from $f_0(X)=(f_0(980),f_0(1500),f_0(1790))$ are all taken into account; and (c) The considered decays could be measured at the ongoing LHCb experiment, consequently, the formalism of two-hadron distribution amplitudes could also be tested by such experiments.

    hep-phhep-exEPJC(2016)·37 citations
20. 20*

    Short path length pQCD corrections to energy loss in the quark gluon plasma

    Isobel Kolbe🇿🇦

    Recent surprising discoveries of collective behaviour of low-$p_T$ particles in $pA$ collisions at LHC hint at the creation of a hot, fluid-like QGP medium. The seemingly conflicting measurements of non-zero particle correlations and $R_{pA}$ that appears to be consistent with unity demand a more careful analysis of the mechanisms at work in such ostensibly minuscule systems. We study the way in which energy is dissipated in the QGP created in $pA$ collisions by calculating, in pQCD, the short separation distance corrections to the well-known DGLV energy loss formulae that have produced excellent predictions for $AA$ collisions. We find that, shockingly, due to the large formation time (compared to the $1/\mu$ Debye screening length) assumption that was used in the original DGLV calculation, a highly non-trivial cancellation of correction terms results in a null short path length correction to the DGLV energy loss formula. We investigate the effect of relaxing the large formation time assumption in the final stages of the calculation -- doing so throughout the calculation adds immense calculational complexity -- and find, since the separation distance between production and scattering centre is integrated over from $0$ to $\infty$, $\gtrsim 100\%$ corrections, even in the large path length approximation employed by DGLV.

    hep-ph10 citations
21. 21*

    Gell-Mann--Low scheme for the Standard Model

    Grigorii B. Pivovarov🇷🇺

    I describe a version of the Gell-Mann--Low scheme which is applicable to the Standard Model. First, I give a procedure for extracting input parameters of the theory from the Green's functions. After that, an iterative procedure of expressing the Green's functions in terms of the above parameters is given.

    hep-phhep-thInt.J.Mod.Phys.Conf.Ser.(2015)·0 citations
22. 22*

    Scalar isovector resonance photoproduction through the final state meson-meson interactions

    L. Bibrzycki (1)🇵🇱 · R. Kaminski (2) ((1) Pedagogical University of Cracow, (2) H. Niewodniczanski Institute of Nuclear Physics PAN)🇵🇱

    We construct the amplitudes of $\pi \eta$ photoproduction taking into account the effects of the $\pi \eta$ - $K\bar{K}$ interchannel coupling. The idea of our model is close to the molecular description of scalar resonances with exception that apart from the pseudoscalar loops we include also vector mesons in the intermediate state loops. These amplitudes are used to calculate the $S$-wave cross sections and mass distributions in the $\pi \eta$ effective mass region corresponding to the scalar resonances $a_0(980)$ and $a_0(1450)$. The values we obtained for $a_0(980)$ are comparable with predictions of other models while the cross section for $a_0(1450)$ is about an order of magnitude larger than prediction based on the quark model. We show that the amplitudes with loops containing vector mesons calculated in the on-shell approximation are not suppressed in contrast to amplitudes containing only pseudoscalar loops. We estimate the cross sections for the $P$- and $D$- waves in the $\pi \eta$ channel.

    hep-phInt.J.Mod.Phys.A(2016)·2 citations
23. 23*

    pp -> ttj + X matched to the Nagy-Soper parton shower at NLO QCD

    Manfred Kraus🇩🇪

    We briefly summarize the Nagy-Soper parton shower and the MC@NLO-like matching scheme. Results obtained using HELAC-NLO framework in conjunction with DEDUCTOR for top quark pair production in association with one hard jet at the LHC are presented. A comparison of our results with other matching schemes and other parton showers is also discussed for various observables.

    hep-phPoS(2015)·0 citations
24. 24*

    Dilepton events with displaced vertices, double beta decay, and resonant leptogenesis with Type-II seesaw dominance, TeV scale $Z^{\prime }$ and heavy neutrinos

    Bidyut Prava Nayak🇮🇳 · M. K. Parida🇮🇳

    In a class of Type-II seesaw dominated $SO(10)$ models proposed recently with heavy neutrinos, extra $Z^{\prime }$ boson, and resonant leptogenesis, at first we show that the lightest first generation sterile neutrino that mediates dominant contributions to neutrinoless double beta decay also generates the displaced vertex leading to verifiable like-sign di-electron as well as di-muon production events outside the LHC detectors having suppressed standard model back-ground and missing energy. Resonant leptogenesis in this case is implemented by a pair of quasi-degenerate sterile neutrinos of the second and the third generations having masses of $\mathcal{O}(500)$ GeV. Then we predict a new alternative scenario where the models allow the second generation sterile neutrino mass to be $\mathcal{O}(10)$ GeV capable of mediating the dominant double beta decay as well as the displaced vertices for significantly improved number of like-sign dilepton events in different channels. Resonant leptogenesis in this alternative scenario is mediated by a pair of heavy quasi-degenerate sterile neutrino masses of the first and the third generations. In addition to QD type light neutrino mass hierarchy, we also show how these results are derived for the NH case. We also discuss $Z^{\prime }$ production cross sections at $\sqrt{s}=14$ TeV run-II of LHC and also at ILC. While the lepton flavour violating branching ratios are only few to four orders less than the current experimental bounds, proton lifetime predictions are accessible to ongoing Super K. or Hyper K. searches.

    hep-ph6 citations
25. 25*

    A 'soft+hard' model for Pion, Kaon, and Proton Spectra and $v_2$ measured in PbPb Collisions at $\sqrt{s}=2.76A$TeV

    Gergely Gábor Barnaföldi🇭🇺 · Károly Ürmössy🇭🇺 · Gábor Bíró🇭🇺

    Hadron spectra measured in high-energy collisions present distributions which can be derived from the non-extensive statistical and thermodynamical phenomena. Based on earlier theoretical developments, it seems, the methods are very applicable for jets hadronization processes in electron-positron, proton-proton, and even in heavy-ion collisions. Here, we present what can was learnt from the recent theoretical and phenomenological developments: transverse momentum spectra and azimuthal anisotropy ($v_2$) of charge averaged pions, kaons and protons stemming from central Pb+Pb collisions at $\sqrt{s}$ = 2.76 ATeV are described \textit{analytically} in a `soft + hard' model. In this model, we propose that hadron yields produced in heavy-ion collisions are simply the sum of yields stemming from jets (hard yields) in addition to the yields originating from the Quark-Gluon Plasma (soft yields). The hadron spectra in both types of yields are approximated by the Tsallis--Pareto like distribution.

    hep-phJ.Phys.Conf.Ser.(2015)·9 citations
26. 26*

    Global $U(1{)}_Y$xBRST symmetry and the LSS theorem: Ward-Takahashi identities governing Green's functions, on-shell T-Matrix elements, and the effective potential, in the spontaneously broken extended Abelian Higgs model

    Bryan W. Lynn🇺🇸 · Glenn D. Starkman🇺🇸

    The weak-scale U(1) Abelian Higgs Model (AHM) is the simplest spontaneous symmetry breaking (SSB) gauge theory. The extended AHM (E-AHM) adds certain heavy scalars $\Phi$ and fermions $\psi$. In Lorenz gauge, these theories have a global U(1) conserved physical current, but no conserved charge. As shown by Kibble, the Goldstone theorem applies, there is a massless derivatively coupled Nambu-Goldstone boson (NGB). Proof of all-loop-orders renormalizability and unitarity is tricky because the BRST-invariant Lagrangian is not U(1) symmetric. Nevertheless, Slavnov-Taylor identities guarantee that on-shell T-matrix elements of physical states are independent of anomaly-free gauge transformations. We observe that they are therefore also independent of the usual anomaly-free U(1) global transformations. It follows that the associated global current, is exactly conserved for amplitudes of physical states. We identify corresponding Ward-Takahashi identities (WTI). In Lorenz gauge, two towers of "1-soft-pion" global WTI govern the scalar-sector, and represent a new global U(1)xBRST symmetry not of the Lagrangian but of the physics. The first gives relations among off-shell Green's functions, the second governs on-shell T-matrix elements, replacing the Adler self-consistency conditions. These WTI constrain the all-loop-orders scalar-sector low-energy effective Lagrangian. Consequently, certain heavy CP-conserving heavy matter representations decouple completely in the $M_{Heavy}^2/m_{Weak}^2\to \infty$ limit. SSB (E-)AHM physics therefore has more symmetry than does its BRST-invariant Lagrantian. The NGB decouples from the observable particle spectrum in the usual way, when the observable vector absorbs it, as if it were a gauge transformation, hiding both towers of WTI from observable particle physics.

    hep-phPRD(2017)·2 citations
27. 27*

    Global $SU(3{)}_C\times SU(2{)}_L\times U(1{)}_Y$ linear sigma model: axial-vector Ward Takahashi identities, and decoupling of certain heavy BSM particles due to the Goldstone theorem

    Bryan W. Lynn🇺🇸 · Glenn D. Starkman🇺🇸

    Dedicated to the memory of Raymond Stora (1930-2015). In the $SU(2{)}_L\times SU(2{)}_R$ Linear Sigma Model with PCAC, towers of Ward-Takahashi Identities (WTI) have long been known to give relations among 1-Scalar-Particle-Irreducible Green's functions, and among I- Scalar-Particle-Reducible T-Matrix elements, for external scalars (i.e. the Brout-Englert-Higgs scalar and 3 pseudoscalars). We extend these WTI and the resulting relations to the $SU(3{)}_C\times SU(2{)}_L\times U(1{)}_Y$ Linear Sigma Model including the heaviest generation of Standard Model (SM) fermions supplemented with the minimum necessary neutrino content -- right-handed neutrinos and Yukawa-coupling-induced Dirac neutrino mass. We extract powerful constraints on the effective Lagrangian: e.g. showing that they make separate tadpole renormalization unnecessary, and guarantee infra-red finiteness. Crucially, ultra-violet quadratic divergences (UVQD) and all other relevant operators contribute only to $m_{\pi }^2$, a Nambu-Goldstone boson (NGB) mass-squared. A WTI between T-Matrix elements (i.e. the Goldstone Theorem) then enforces $m_{\pi }^2=0$ for the true NGB in the spontaneous symmetry breaking mode of the theory. All relevant operator contributions originating to all-loop-orders from virtual scalars, quarks and leptons, vanish identically! Our regularization-scheme-independent results are unchanged by the addition of certain heavy CP-conserving matter, such as originate in certain Beyond the SM models. We demonstrate this with two examples: a heavy singlet real scalar field with $Z_2$ symmetry and no VEV; and a heavy singlet right-handed Type I See-saw Majorana neutrino. Specifically, we prove that these heavy degrees of freedom decouple completely from the low-energy effective Lagrangian, contributing only irrelevant operators after quartic-coupling renormalization.

    hep-phPRD(2017)·4 citations
28. 28*

    Schottky Anomaly and Hadronic Spectrum

    Aritra Biswas🇮🇳 · M V N Murthy🇮🇳 · Nita Sinha🇮🇳

    We show that the hadronic "heat capacity" calculated as a function of temperature may be used to infer the possible presence of different scales underlying the dynamical structure of hadronic resonances using the phenomenon of Schottky anomaly. We first demonstrate this possibility with well known meson spectrum in various channels and comment on the possibility of using this method as a diagnostic to distinguish the exotic states.

    hep-phPRD(2015)·2 citations
29. 29*

    Magnetic moment for the negative parity $\Lambda \to {\Sigma }^0$ transition in light cone QCD sum rules

    T. M. Aliev🇹🇷 · M. Savcı🇹🇷

    The magnetic moment of the $\Lambda \to {\Sigma }^0$ transition between negative parity, baryons is calculated in framework of the QCD sum rules approach, using the general form of the interpolating currents. The pollution arising from the positive--to--positive, and positive to negative parity baryons are eliminated by constructing the sum rules for different Lorentz structures. Nonzero value of the considered magnetic moment can be attributed to the violation of the $SU(3)$ symmetry.

    hep-phPLB(2016)·0 citations
30. 30*

    Electromagnetic triangle anomaly and neutral pion condensation in QCD vacuum

    Gaoqing Cao🇨🇳 · Xu-Guang Huang🇨🇳

    We study the QCD vacuum structure under the influence of an electromagnetic field with a nonzero second Lorentz invariant $I_2=\vec{E}\cdot \vec{B}$. We show that the presence of $I_2$ can induce neutral pion (${\pi }^0$) condensation in the QCD vacuum through the electromagnetic triangle anomaly. Within the frameworks of chiral perturbation theory at leading small-momenta expansion as well as the Nambu--Jona-Lasinio model at leading $1/N_c$ expansion, we quantify the dependence of the ${\pi }^0$ condensate on $I_2$. The stability of the ${\pi }^0$-condensed vacuum against the Schwinger charged pair production due to electric field is also discussed.

    hep-phhep-latnucl-thPLB(2016)·46 citations
31. 31*

    Determination of the $\Sigma$--$\Lambda$ mixing angle from QCD sum rules

    T. M. Aliev (1)🇹🇷 · T. Barakat (2)🇸🇦 · M. Savcı (1) ((1) Middle East Technical University/Ankara/Turkey, (2) King Saud University/Riyadh/Saudi Arabia)🇹🇷

    The $\Sigma$--$\Lambda$ mixing angle is calculated in framework of the QCD sum rules. We find that our prediction for the mixing angle is $(1.00\pm 0.15{)}^0$ which is in good agreement with the quark model prediction, and approximately two times larger than the recent lattice QCD calculations.

    hep-phJHEP(2016)·2 citations
32. 32*

    Leptoquark effects on $b\to s\nu \bar{\nu }$ and $B\to K{l}^{+}{l}^{-}$ decay processes

    Suchismita Sahoo🇮🇳 · Rukmani Mohanta🇮🇳

    We study the rare semileptonic decays of $B$ mesons induced by $b\to s\nu \bar{\nu }$ as well as $b\to s{l}^{+}{l}^{-}$ transitions in the scalar leptoquark model where the leptoquarks transform as $(3,2,7/6)$ and $(3,2,1/6)$ under the standard model gauge group. The leptoquark parameter space is constrained using the most recent experimental results on $\mathrm{Br}(B_s\to {\mu }^{+}{\mu }^{-})$ and $\mathrm{Br}(B_d\to X_s{\mu }^{+}{\mu }^{-})$ processes. Considering only the baryon number conserving leptoquark interactions, we estimate the branching ratios for the exclusive $\bar{B}\to {\bar{K}}^{(\ast )}\nu \bar{\nu }$ and inclusive $B\to X_s\nu \bar{\nu }$ decay processes by using the constraint parameters. We also obtain the low recoil (large lepton invariant mass, i.e., $q^2\sim m_b^2$) predictions for the angular distribution of $\bar{B}\to \bar{K}{l}^{+}{l}^{-}$ process and several other observables including the flat term and lepton flavour non-universality factor in this model.

    hep-phNew J.Phys.(2016)·34 citations
33. 33*

    Standard Model Theory

    Stefan Dittmaier🇩🇪

    Recent progress in the field of precision calculations for Standard Model processes at the LHC is reviewed, highlighting examples of weak gauge-boson and Higgs-boson production, as discussed at the 27th Rencontres de Blois, 2015.

    hep-ph1 citation
34. 34*

    Fermion dark matter from SO(10)

    Carolina Arbelaez🇨🇱 · Robinson Longas🇨🇴 · Diego Restrepo🇨🇴 · Oscar Zapata🇨🇴

    We construct and analyze nonsupersymmetric SO(10) standard model extensions which explain dark matter (DM) through the fermionic Higgs portal. In these SO(10)-based models the DM particle is naturally stable since a $Z_2$ discrete symmetry, the matter parity, is left at the end of the symmetry breaking chain to the standard model. Potentially realistic models contain the $10$ and $45$ fermionic representations from which a neutralino-like mass matrix with arbitrary mixings can be obtained. Two different SO(10) breaking chains will be analyzed in light of gauge coupling unification: the standard path $\text{SU}(5)\times U(1{)}_X$ and the left-right symmetry intermediate chain. The former opens the possibility of a split supersymmetric-like spectrum with an additional (inert) scalar doublet, while the later requires additional exotic scalar representations associated to the breaking of the left-right symmetry.

    hep-phPRD(2016)·30 citations
35. 35*

    Equation of State in Non-Zero Magnetic Field

    Nada Ezzelarab🇪🇬 · Abdel Magied Diab🇪🇬 · Abdel Nasser Tawfik (Egyptian Ctr. Theor. Phys., Cairo, WLCAPP, Cairo.)🇪🇬

    The Polyakov linear-sigma model (PLSM) and Hadron Resonance Gas (HRG) model are considered to study the hadronic and partonic equation(s) of state, the pressure, and response to finite magnetic field, the magnetization. The results are confronted to recent lattice QCD calculations. Both models are in fairly good agreement with the lattice.

    hep-phhep-latJ.Phys.Conf.Ser.(2016)·7 citations
36. 36*

    Examination of uncertainties in nuclear data for cosmic ray physics with the AMS experiment

    Nicola Tomassetti🇫🇷

    High-energy Li-Be-B nuclei in cosmic rays are being measured with unprecedent accuracy by the AMS experiment. These data bring valuable information to the cosmic ray propagation physics. In particular, combined measurements of B/C and Be/B ratios may allow to break the parameter degeneracy between the cosmic-ray diffusion coefficient and the size of the propagation region, which is crucial for dark matter searches. The parameter determination relies in the calculation of the Be and B production from collisions of heavier nuclei with the gas. Using the available cross-section data, I present for the first time an evaluation of the nuclear uncertainties and their impact in constraining the propagation models. I found that the AMS experiment can provide tight constraints on the transport parameters allowing to resolutely break the degeneracy, while nuclear uncertainties in the models are found to be a major limiting factor. Once these uncertainties are accounted, the degeneracy remains poorly resolved. In particular, the Be/B ratio at ~1 - 10 GeV/n is found not to bring valuable information for the parameter extraction. On the other hand, precise Be/B data at higher energy may be useful to test the nuclear physics inputs of the models.

    ↳ astro-ph.HEhep-phnucl-exPRC(2015)·31 citations
37. 37*

    The curvature of the freeze-out line in heavy ion collisions

    A. Bazavov🇺🇸 · H.-T. Ding🇨🇳 · P. Hegde🇨🇳 · O. Kaczmarek🇩🇪 · F. Karsch🇩🇪 · E. Laermann🇩🇪 · Swagato Mukherjee🇺🇸 · H. Ohno🇺🇸 · P. Petreczky🇺🇸 · C.Schmidt🇩🇪 · S. Sharma🇺🇸 · W. Soeldner🇩🇪 · M. Wagner🇺🇸

    We calculate the mean and variance of net-baryon number and net-electric charge distributions from Quantum Chromodynamics (QCD) using a next-to-leading order Taylor expansion in terms of temperature and chemical potentials. We compare these expansions with experimental data from STAR and PHENIX, determine the freeze-out temperature in the limit of vanishing baryon chemical potential, and, for the first time, constrain the curvature of the freeze-out line through a direct comparison between experimental data on net-charge fluctuations and a QCD calculation. We obtain a bound on the curvature coefficient, kappa_2^f < 0.011, that is compatible with lattice QCD results on the curvature of the QCD transition line.

    ↳ hep-lathep-phnucl-thPRD(2016)·45 citations
38. 38*

    Exact solutions of the Boltzmann equation and optimized hydrodynamic approaches for relativistic heavy-ion collisions

    U. Heinz (Ohio State)🇺🇸 · D. Bazow (Ohio State)🇺🇸 · G.S. Denicol (McGill)🇨🇦 · M. Martinez (Ohio State)🇺🇸 · M. Nopoush (Kent State)🇺🇸 · J. Noronha (U. Sao Paulo)🇧🇷 · R. Ryblewski (Krakow)🇵🇱 · M. Strickland (Kent State)🇺🇸

    Several recent results are reported from work aiming to improve the quantitative precision of relativistic viscous fluid dynamics for relativistic heavy-ion collisions. The dense matter created in such collisions expands in a highly anisotropic manner. Due to viscous effects this also renders the local momentum distribution anisotropic. Optimized hydrodynamic approaches account for these anisotropies already at leading order in a gradient expansion. Recently discovered exact solutions of the relativistic Boltzmann equation in anisotropically expanding systems provide a powerful testbed for such improved hydrodynamic approximations. We present the latest status of our quest for a formulation of relativistic viscous fluid dynamics that is optimized for applications to relativistic heavy-ion collisions.

    ↳ nucl-thhep-phnucl-exNucl.Part.Phys.Proc.(2016)·26 citations
39. 39*

    Large Blue Spectral Isocurvature Spectral Index Signals Time-Dependent Mass

    Daniel J. H. Chung🇺🇸

    We show that if a spectator linear isocurvature dark matter field degree of freedom has a constant mass through its entire evolution history, the maximum measurable isocurvature spectral index that is consistent with the current tensor-to-scalar ratio bound is about 2.4, even if experiments can be sensitive to a $10^{-6}$ contamination of the predominantly adiabatic power spectrum with an isocurvature power spectrum at the shortest observable length scales. Hence, any foreseeable future measurement of a blue isocurvature spectral index larger than about 2.4 may provide nontrivial evidence for dynamical degrees of freedom with time-dependent masses during inflation. The bound is not sensitive to the details of the reheating scenario and can be made mildly smaller if the tensor-to-scalar ratio is better constrained in the future.

    ↳ astro-ph.COhep-phPRD(2016)·15 citations
40. 40*

    Condensation of Galactic Cold Dark Matter

    Luca Visinelli🇺🇸

    We consider the steady-state regime describing the density profile of a dark matter halo, if dark matter is treated as a Bose-Einstein condensate. We first solve the fluid equation for "canonical" cold dark matter, obtaining a class of density profiles which includes the Navarro-Frenk-White profile, and which diverge at the halo core. We then solve numerically the equation obtained when an additional "quantum pressure" term is included in the computation of the density profile. The solution to this latter case is finite at the halo core, possibly avoiding the "cuspy halo problem" present in some cold dark matter theories. Within the model proposed, we predict the mass of the cold dark matter particle to be of the order of M_chi c2 = 10^-24 eV, which is of the same order of magnitude as that predicted in ultra-light scalar cold dark matter models. Finally, we derive the differential equation describing perturbations in the density and the pressure of the dark matter fluid.

    ↳ astro-ph.COhep-phJCAP(2016)·7 citations
41. 41*

    Non-manifest symmetries in quantum field theory

    Peter Lowdon🇨🇭

    Non-manifest symmetries are an important feature of quantum field theories (QFTs), and yet their characteristics are not fully understood. In particular, the construction of the charge operators associated with these symmetries is ambiguous. In this paper we adopt a rigorous axiomatic approach in order to address this issue. It turns out that charge operators of non-manifest symmetries are not unique, and that although this does not affect their property as generators of the corresponding symmetry transformations, additional physical input is required in order to determine how they act on states. Applying these results to the examples of spacetime translation and Lorentz symmetry, it follows that the assumption that the vacuum is the unique translationally invariant state is sufficient to uniquely define the charges associated with these symmetries. In the case of supersymmetry though there exists no such physical requirement, and this therefore implies that the supersymmetric charge, and hence the supersymmetric space of states, is not uniquely defined.

    ↳ hep-thhep-ph0 citations
42. 42*

    Natural solution to the naturalness problem -- Universe does fine-tuning

    Yuta Hamada🇯🇵 · Hikaru Kawai🇯🇵 · Kiyoharu Kawana🇯🇵

    We propose a new mechanism to solve the fine-tuning problem. We start from a multi-local action $S={\sum }_i{c}_i{S}_i+{\sum }_{i,j}{c}_{i,j}{S}_i{S}_j+{\sum }_{i,j,k}{c}_{i,j,k}{S}_i{S}_j{S}_k+\cdots$, where $S_i$'s are ordinary local actions. Then, the partition function of this system is given by \begin{equation} Z=\int d\overrightarrow{\lambda} f(\overrightarrow{\lambda})\langle f|T\exp\left(-i\int_{0}^{+\infty}dt\hat{H}(\overrightarrow{\lambda};a_{cl}(t))\right)|i\rangle,\nonumber\end{equation} where $\overrightarrow{\lambda }$ represents the parameters of the system whose Hamiltonian is given by $\hat{H}(\overrightarrow{\lambda };a_{cl}(t))$, $a_{cl}(t)$ is the radius of the universe determined by the Friedman equation, and $f(\overrightarrow{\lambda })$, which is determined by $S$, is a smooth function of $\overrightarrow{\lambda }$. If a value of $\overrightarrow{\lambda }$, ${\overrightarrow{\lambda }}_0$, dominates in the integral, we can interpret that the parameters are dynamically tuned to ${\overrightarrow{\lambda }}_0$. We show that indeed it happens in some realistic systems. In particular, we consider the strong CP problem, multiple point criticality principle and cosmological constant problem. It is interesting that these different phenomena can be explained by one mechanism.

    ↳ hep-thgr-qchep-phPTEP(2015)·32 citations
43. 43*

    Precision Experiments at LEP

    Wim de Boer (IEKP, Karlsruhe Institute of Technology, Germany)🇩🇪

    The Large Electron Positron Collider (LEP) established the Standard Model (SM) of particle physics with unprecedented precision, including all its radiative corrections. These led to predictions for the masses of the top quark and Higgs boson, which were beautifully confirmed later on. After these precision measurements the Nobel Prize in Physics was awarded in 1999 jointly to 't Hooft and Veltman "for elucidating the quantum structure of electroweak interactions in physics". Another hallmark of the LEP results were the precise measurements of the gauge coupling constants, which excluded unification of the forces within the SM, but allowed unification within the supersymmetric extension of the SM. This increased the interest in Supersymmetry (SUSY) and Grand Unified Theories, especially since the SM has no candidate for the elusive dark matter, while Supersymmetry provides an excellent candidate for dark matter. In addition, Supersymmetry removes the quadratic divergencies of the SM and {\it predicts} the Higgs mechanism from radiative electroweak symmetry breaking with a SM-like Higgs boson having a mass below 130 GeV in agreement with the Higgs boson discovery at the LHC. However, the predicted SUSY particles have not been found either because they are too heavy for the present LHC energy and luminosity or Nature has found alternative ways to circumvent the shortcomings of the SM.

    ↳ hep-exhep-phAdv.Ser.Direct.High Energy Phys.(2015)·10 citations
44. 44*

    Chiral symmetry aspects in the open charm sector

    Thomas Buchheim🇩🇪 · Thomas Hilger🇦🇹 · Burkhard Kampfer🇩🇪

    QCD sum rules serve as tools to investigate changing hadronic properties in a hot and/or dense nuclear medium. The role of chiral symmetry breaking and restoration effects in a medium can be addressed also in the heavy-light meson sector. Thus, we consider Weinberg sum rules which refer to chiral partner mesons composed of a light and a heavy quark.

    ↳ nucl-thhep-phJ.Phys.Conf.Ser.(2016)·9 citations
45. 45*

    The $K^{-}p\to f_1(1285)\Lambda$ reaction within an effective Lagrangian approach

    Ju-Jun Xie🇨🇳

    The production of the $f_1(1285)$ resonance in the reaction of $K^{-}p\to f_1(1285)\Lambda$ is studied within an effective Lagrangian approach. The production process is described by the $t$ channel $K^{\ast +}$ meson exchange. My theoretical approach is based on the results of chiral unitary theory where the $f_1(1285)$ resonance is dynamically generated from the single channel $\bar{K}{K}^{\ast }-c.c.$ interaction. The total and differential cross sections of the $K^{-}p\to f_1(1285)\Lambda$ reaction are evaluated. Within the coupling constant of the $f_1(1285)$ to $\bar{K}{K}^{\ast }$ channel obtained from the chiral unitary theory and a cut off parameter ${\Lambda }_c\sim 1.5$ GeV in the form factors, the experimental measurement can be reproduced. This production process would provide further evidence for the $\bar{K}{K}^{\ast }-c.c.$ nature of the $f_1(1285)$ state.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2015)·15 citations
46. 46*

    $B\to K{l}^{+}{l}^{-}$ decay form factors from three-flavor lattice QCD

    Jon A. Bailey🇰🇷 · A. Bazavov🇺🇸 · C. Bernard🇺🇸 · C. M. Bouchard🇺🇸 · C. DeTar🇺🇸 · Daping Du🇺🇸 · A. X. El-Khadra🇺🇸 · J. Foley🇺🇸 · E. D. Freeland🇺🇸 · E. Gámiz🇪🇸 · Steven Gottlieb🇺🇸 · U. M. Heller🇺🇸 and 15 other authors

    We compute the form factors for the $B\to K{l}^{+}{l}^{-}$ semileptonic decay process in lattice QCD using gauge-field ensembles with 2+1 flavors of sea quark, generated by the MILC Collaboration. The ensembles span lattice spacings from 0.12 to 0.045 fm and have multiple sea-quark masses to help control the chiral extrapolation. The asqtad improved staggered action is used for the light valence and sea quarks, and the clover action with the Fermilab interpretation is used for the heavy $b$ quark. We present results for the form factors $f_{+}(q^2)$, $f_0(q^2)$, and $f_T(q^2)$, where $q^2$ is the momentum transfer, together with a comprehensive examination of systematic errors. Lattice QCD determines the form factors for a limited range of $q^2$, and we use the model-independent $z$ expansion to cover the whole kinematically allowed range. We present our final form-factor results as coefficients of the $z$ expansion and the correlations between them, where the errors on the coefficients include statistical and all systematic uncertainties. We use this complete description of the form factors to test QCD predictions of the form factors at high and low $q^2$. We also compare a Standard-Model calculation of the branching ratio for $B\to K{l}^{+}{l}^{-}$ with experimental data.

    ↳ hep-lathep-phPRD(2016)·219 citations
47. 47*

    The pion quasiparticle in the low-temperature phase of QCD

    Bastian B. Brandt🇩🇪 · Anthony Francis🇨🇦 · Harvey B. Meyer🇩🇪 · Daniel Robaina🇩🇪

    We investigate the properties of the pion quasiparticle in the low-temperature phase of two-flavor QCD on the lattice with support from chiral effective theory. We find that the pion quasiparticle mass is significantly reduced compared to its value in the vacuum, in contrast to the static screening mass, which increases with temperature. By a simple argument, the two masses are expected to determine the quasiparticle dispersion relation near the chiral limit. Analyzing two-point functions of the axial charge density at non-vanishing spatial momentum, we find that the predicted dispersion relation and the residue of the pion pole are simultaneously consistent with the lattice data at low momentum. The test, based on fits to the correlation functions, is confirmed by a second analysis using the Backus-Gilbert method.

    ↳ hep-lathep-phnucl-thPoS(2016)·1 citation
48. 48*

    Toward a simultaneous description of $R_{AA}$ and $v_2$ for heavy quarks

    Santosh K. Das🇮🇹 · Francesco Scardina🇮🇹 · Salvatore Plumari🇮🇹 · Vincenzo Greco🇮🇹

    The two key observables related to heavy quarks that have been measured in RHIC and LHC energies are the nuclear suppression factor $R_{AA}$ and the elliptic flow $v_2$. Simultaneous description of these two observables is a top challenge for all the existing models. We have highlighted how a consistent combination of four ingredients i.e the temperature dependence of the energy loss, full solution of the Boltzmann collision integral for the momentum evolution of heavy quark, hadronization by coalescence, then the hadronic rescattering, responsible to address a large part of such a puzzle. We have considered four different models to evaluate the temperature dependence of drag coefficients of the heavy quark in QGP. All these four different models are set to reproduce the same $R_{AA}$ as of the experiments. We have shown that for the same $R_{AA}$, the $v_2$ could be quite different depending on the interaction dynamics as well as other ingredients.

    ↳ nucl-thhep-phJ.Phys.Conf.Ser.(2016)·5 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.