HEP Phenomenology·hep-ph

Wed·Aug 12, 2015Wednesday·August 12, 2015

26 papers—16 primary·10 cross-listed·reconstructed*

01*
Employing Helicity Amplitudes for Resummation
Ian Moult🇺🇸 · Iain W. Stewart🇺🇸 · Frank J. Tackmann🇩🇪 · Wouter J. Waalewijn🇳🇱
Many state-of-the-art QCD calculations for multileg processes use helicity amplitudes as their fundamental ingredients. We construct a simple and easy-to-use helicity operator basis in soft-collinear effective theory (SCET), for which the hard Wilson coefficients from matching QCD onto SCET are directly given in terms of color-ordered helicity amplitudes. Using this basis allows one to seamlessly combine fixed-order helicity amplitudes at any order they are known with a resummation of higher-order logarithmic corrections. In particular, the virtual loop amplitudes can be employed in factorization theorems to make predictions for exclusive jet cross sections without the use of numerical subtraction schemes to handle real-virtual infrared cancellations. We also discuss matching onto SCET in renormalization schemes with helicities in $4$ - and $d$ -dimensions. To demonstrate that our helicity operator basis is easy to use, we provide an explicit construction of the operator basis, as well as results for the hard matching coefficients, for $pp \to H + 0, 1, 2$ jets, $pp \to W / Z / γ + 0, 1, 2$ jets, and $pp \to 2, 3$ jets. These operator bases are completely crossing symmetric, so the results can easily be applied to processes with $e^{+} e^{-}$ and $e^{-} p$ collisions.
hep-phnucl-thPRD(2016)·50 citations
02*
Di-photon "Ridge" in p+p and p+A collisions at RHIC and the LHC
Alex Kovner🇺🇸 · Amir H. Rezaeian🇨🇱
We obtain prompt di-photon cross-section in proton-nucleus collisions in Hamiltonian light-cone approach within a hybrid approximation, treating the projectile proton in the parton model and the target nucleus in the Color-Glass-Condensate approach. We study in details the di-photon correlations in quark-nucleus and proton-nucleus collisions at RHIC and the LHC. We show that the single fragmentation di-photon produces the away side correlations peak, and the double fragmentation component of prompt di-photon is responsible for the near-side peak, and the long-range in rapidity near-side azimuthal collimation, the so-called "ridge" structure. We study the transverse momentum, density and energy dependence of the di-photon ridge and show that it strongly depends on the kinematics and saturation dynamics. We show that while di-photon ridge exists at the LHC in quark-nucleus collisions, the effect disappears in proton-nucleus collisions at the LHC. At RHIC the ridge-type structure persists at low transverse momenta of di-photon even in proton-nucleus collisions. We argue that di-photon correlation measurments in p+A collisions can help to discriminate among models and understand the true origin of the observed di-hadron ridge in p+A collisions. We also show that in addition to the ridge structure, prompt di-photon correlation also exhibits some distinct novel features, including the emergence of away side double-peak structure at intermediate transverse momenta.
hep-phhep-exnucl-exnucl-thPRD(2015)·22 citations
03*
Mixed Stops and the ATLAS on-Z Excess
Jack H. Collins🇺🇸 · Jeff Asaf Dror🇺🇸 · Marco Farina🇺🇸
The ATLAS experiment has recently observed a 3-sigma excess in a channel with a leptonically decaying Z, jets, and ETmiss. It is tantalizing to interpret the signal as the first sign of a natural supersymmetric spectrum. We study such a possibility in a minimal model containing light stops and a neutralino LSP. The signal is characterized by a novel topology (compared to previous attempts) where the Z is emitted from a colored particle in the first step of a decay chain, namely t2 -> t1 Z which is characteristic of mixed stops. We show that the excess is compatible with a compressed stop spectrum and is not excluded by any other relevant search, finding some regions of parameter space with signal strength within 1-sigma of that measured by the ATLAS collaboration. In addition, we notice that the corresponding CMS search could be prone to background contamination in unexpected topologies of this kind.
hep-phhep-exPRD(2015)·11 citations
04*
Bounds on higher-order Lorentz-violating photon sector coefficients from an asymmetric optical ring resonator experiment
Stephen R. Parker🇦🇺 · Matthew Mewes🇺🇸 · Fred N. Baynes🇦🇺 · Michael E. Tobar🇦🇺
Optical resonators provide a powerful tool for testing aspects of Lorentz invariance. Here, we present a reanalysis of an experiment where a path asymmetry was created in an optical ring resonator by introducing a dielectric prism in one arm. The frequency difference of the two fundamental counter-propagating modes was then recorded as the apparatus was orientation-modulated in the laboratory. By assuming that the minimal Standard-Model Extension coefficients vanish we are able to place bounds on higher-order parity-odd Lorentz-violating coefficients of the Standard-Model Extension. The results presented in this work set the first constraints on two previously unbounded linear combinations of d=8 parity-odd nonbirefringent nondispersive coefficients of the photon sector.
hep-phgr-qcPLA(2015)·10 citations
05*
IceCube Events from Heavy DM decays through the Right-handed Neutrino Portal
P. Ko🇰🇷 · Yong Tang🇰🇷
The recently observed IceCube PeV events could be due to heavy dark matter (DM) decay. In this paper, we propose a simple DM model with extra $U (1)_{X}$ gauge symmetry and bridge it with standard model particles through heavy right-handed neutrino. The Dirac fermion DM $χ$ with mass ~5 PeV can dominantly decay into a dark Higgs ( $ϕ$ ), the SM Higgs ( $h$ ) and a neutrino ( $ν$ ). If the lifetime of $χ$ is ~O( $1 0^{28}$ ) sec, the resulting neutrino flux can fit data consistently. The neutrino flux from $χ \to ϕ h ν$ in our model is softer than the one predicted from $χ \to ν h$ , for example. We also discuss a possible mechanism to produce DM with the right relic abundance.
hep-phastro-ph.COhep-exPLB(2015)·58 citations
06*
Efficient Numerical Evaluation of Feynman Integral
Zhao Li🇨🇳 · Jian Wang🇩🇪 · Qi-Shu Yan🇨🇳 · Xiaoran Zhao🇨🇳
Feynman loop integrals are a key ingredient for the calculation of higher order radiation effects, and are responsible for reliable and accurate theoretical prediction. We improve the efficiency of numerical integration in sector decomposition by implementing a quasi-Monte Carlo method associated with the CUDA/GPU technique. For demonstration we present the results of several Feynman integrals up to two loops in both Euclidean and physical kinematic regions in comparison with those obtained from FIESTA3. It is shown that both planar and non-planar two-loop master integrals in the physical kinematic region can be evaluated in less than half a minute with $O (1 0^{- 3})$ accuracy, which makes the direct numerical approach viable for precise investigation of higher order effects in multi-loop processes, e.g. the next-to-leading order QCD effect in Higgs pair production via gluon fusion with a finite top quark mass.
hep-phCPC(2016)·45 citations
07*
Polarization in double parton scattering
Tomas Kasemets🇳🇱
We briefly discuss the status of double parton scattering (DPS) on both theoretical and experimental sides and summarize the state of the naive DPS model, where the scatterers are taken completely independent. We then elaborate on some of the effects which are neglected in such an approach, and often ignored in phenomenological studies, with focus on polarization - which arises from the correlation between the spin of two partons inside a proton. Polarization is of particular interest, thanks to its direct and calculable connections to the distribution of particles in the final state. Although the physics described is different, there are strong similarities between polarization in DPS and in single partons scattering with measured transverse momentum, and several of the techniques and results from studies of transverse momentum dependent parton distributions can be translated into the setting of double parton scattering.
hep-phPoS(2015)·0 citations
08*
Transverse Momentum Dependent (Un)polarized Gluon Distributions in Higgs Production
Tomas Kasemets🇳🇱
We combine soft and collinear matrix elements to define transverse momentum dependent parton distributions (TMDs) for gluons, free from rapidity divergences. We establish a factorization theorem at next-to-leading order for the Higgs boson transverse momentum ( $q_{T}$ ) spectrum, and use it to derive evolution equations for gluon TMDs. The evolution for all gluon TMDs is driven by a universal kernel, i.e. the same for all polarizations. In the region of intermediate $q_{T}$ we match the unpolarized, helicity and linearly polarized gluon distributions onto PDFs. We calculate the resummed Higgs transverse momentum distribution at NNLL, including the contribution of the linearly polarized gluons, and investigate the impact of non-perturbative models for the transverse distribution of gluons inside the proton.
hep-phPoS(2015)·0 citations
09*
(O)Mega Split
Karim Benakli🇫🇷 · Luc Darmé🇫🇷 · Mark Goodsell🇫🇷
We study two realisations of the Fake Split Supersymmetry Model (FSSM), the simplest model that can easily reproduce the experimental value of the Higgs mass for an arbitrarily high supersymmetry scale, as a consequence of swapping higgsinos for equivalent states, fake higgsinos, with suppressed Yukawa couplings. If the LSP is identified as the main Dark matter component, then a standard thermal history of the Universe implies upper bounds on the supersymmetry scale, which we derive. On the other hand, we show that renormalisation group running of soft masses above the supersymmetry scale barely constrains the model - in stark contrast to Split Supersymmetry - and hence we can have a "Mega Split" spectrum even with all of these assumptions and constraints, which include the requirements of a correct relic abundance, a gluino life-time compatible with Big Bang Nucleosynthesis and absence of signals in present direct detection experiments of inelastic dark matter. In an appendix we describe a related scenario, Fake Split Extended Supersymmetry, which enjoys similar properties.
hep-phJHEP(2015)·11 citations
10*
CGC/saturation approach: a new impact-parameter dependent model
Carlos Contreras (UTFSM)🇦🇺 · Eugene Levin (Tel Aviv U. /UTFSM)🇮🇱 · Irina Potashnikova (UTFSM)🇨🇱
{In this paper we propose a new impact-parameter dependent CGC/saturation model. We introduce two new features in the model that make it consistent with what we know theoretically about the deep inelastic scattering. They are: the use of the exact form of the solution to the non-linear (BK) equation, whereas in all previous attempts only the form of $r^{2} Q_{s}^{2}$ dependence, has been taken into account; and the large impact parameter dependence, through the $b$ -dependence of the saturation momentum which reproduce the correct behaviour of the amplitude at large impact parameters $b$ ( $A \propto exp \Lb - μ b \Rb$ ) as well as at large momentum transferred $Q_{T}$ ( $A$ decreases as a power of $Q_{T}$ as it follows from perturbative QCD). These improvement compared to all previous attempts to build such models, allows us to claim, that the experimental data are in accord with the prediction of CGC/saturation approach while previously, based on similar models, we could only conclude that the DIS data, perhaps, can be described by introducing the shadowing corrections at small photon virtualities.
hep-phNPA(2016)·19 citations
11*
One-loop anomalous dimension of top-partner hyperbaryons in a family of composite Higgs models
Thomas DeGrand🇺🇸 · Yigal Shamir🇮🇱
An important ingredient of many composite-Higgs scenarios is partial compositeness: a mass for the top quark is generated via mixing with baryonic operators of the same new strong dynamics that produces the composite Higgs particle. These baryonic operators are scale dependent. We construct these operators, and calculate their one-loop anomalous dimension, in a set of ultraviolet completions of the Standard Model proposed by Ferretti and Karateev.
hep-phhep-latPRD(2015)·25 citations
12*
$T_{7}$ flavor symmetry scheme for understanding neutrino mass and mixing in 3-3-1 model with neutral leptons
V.V.Vien🇻🇳
We construct a new version for the 3-3-1 model based on $T_{7}$ flavor symmetry where the left-handed leptons under $T_{7}$ differ from those of our previous work while the $SU (3)_{C} \otimes SU (3)_{L} \otimes U (1)_{X}$ gauge symmetry is retain. The flavor mixing patterns and mass splitting are obtained without perturbation. The realistic lepton mixing can be obtained if both the direction of breakings $T_{7} \to Z_{3}$ and $Z_{3} \to {Identity}$ are taken place in neutrino sector. Maximal CP violation is predicted and CKM matrix is the identity matrix at the tree-level.
hep-phMod.Phys.Lett.A(2014)·24 citations
13*
A Radiative Model for the Weak Scale and Neutrino Mass via Dark Matter
Amine Ahriche (Jijel U. & ICTP, Trieste)🇩🇿 · Kristian L. McDonald (Sydney U.)🇦🇺 · Salah Nasri (United Arab Emirates U.)🇦🇪
We present a three-loop model of neutrino mass in which both the weak scale and neutrino mass arise as radiative effects. In this approach, the scales for electroweak symmetry breaking, dark matter, and the exotics responsible for neutrino mass, are related due to an underlying scale-invariance. This motivates the otherwise-independent O(TeV) exotic masses usually found in three-loop models of neutrino mass. We demonstrate the existence of viable parameter space and show that the model can be probed at colliders, precision experiments, and dark matter direct-detection experiments.
hep-phJHEP(2016)·64 citations
14*
Renormalization Group Optimized Perturbation Theory at Finite Temperatures
J.-L. Kneur🇫🇷 · M. B. Pinto🇧🇷
A recently developed variant of the so-called optimized perturbation theory (OPT), making it perturbatively consistent with renormalization group (RG) properties, RGOPT, was shown to drastically improve its convergence for zero temperature theories. Here the RGOPT adapted to finite temperature is illustrated with a detailed evaluation of the two-loop pressure for the thermal scalar $λ ϕ^{4}$ field theory. We show that already at the simple one-loop level this quantity is exactly scale-invariant by construction and turns out to qualitatively reproduce, with a rather simple procedure, results from more sophisticated resummation methods at two-loop order, such as the two-particle irreducible approach typically. This lowest order also reproduces the exact large- $N$ results of the $O (N)$ model. Although very close in spirit, our RGOPT method and corresponding results differ drastically from similar variational approaches, such as the screened perturbation theory or its QCD-version, the (resummed) hard thermal loop perturbation theory. The latter approaches exhibit a sensibly degrading scale dependence at higher orders, which we identify as a consequence of missing RG invariance. In contrast RGOPT gives a considerably reduced scale dependence at two-loop level, even for relatively large coupling values $λ /24 \sim O (1)$ , making results much more stable as compared with standard perturbation theory, with expected similar properties for thermal QCD.
hep-phPRD(2015)·30 citations
15*
Effects of kinematic cuts on net-electric charge fluctuations
Frithjof Karsch🇩🇪 · Kenji Morita🇯🇵 · Krzysztof Redlich🇵🇱
The effects of kinematic cuts on electric charge fluctuations in a gas of charged particles are discussed. We consider a very transparent example of an ideal pion gas with quantum statistics, which can be viewed as a multi-component gas of Boltzmann particles with different charges and masses. Cumulants of net-electric charge fluctuations $χ_{n}^{Q}$ are calculated in a static and expanding medium with flow parameters adjusted to the experimental data. We show that the transverse momentum cut, $p_{t_{min}} \leq p_{t} \leq p_{t_{max}}$ , weakens the effects of Bose statistics, i.e. contributions of effectively multi-charged states to higher order moments. Consequently, cuts in $p_{t}$ modify the experimentally measured cumulants and their ratios. We discuss the influence of kinematic cuts on the ratio of mean and variance of electric charge fluctuations in a hadron resonance gas, in the light of recent data of the STAR and PHENIX Collaborations. We find that the different momentum cuts of $p_{t_{min}} = 0.2$ ~GeV (STAR) and $p_{t_{min}} = 0.3$ ~GeV (PHENIX) are responsible for more than 30\% of the difference between these two data sets. We argue that the $p_{t}$ cuts imposed on charged particles will influence the normalized kurtosis { $κ_{Q} σ_{Q}^{2} = χ_{4}^{Q} / χ_{2}^{Q}$ } of the electric charge fluctuations. In particular, the reduction of $κ_{Q} σ_{Q}^{2}$ with increasing $p_{t_{min}}$ will lead to differences between PHENIX and STAR data of $O (6%)$ which currently are buried under large statistical and systematic errors. We furthermore introduce the relation between momentum cut-off and finite volume effects, which is of relevance for the comparison between experimental data and lattice QCD calculations.
hep-phhep-latnucl-exnucl-thPRC(2016)·49 citations
16*
Neutrino Oscillations With Three Active and Three Sterile Neutrinos
Leonard S. Kisslinger🇺🇸
This is an extension of estimates of the probability of $ν$ to $e$ neutrino oscillation with one sterile neutrino to three sterile neutrinos, using a 6x6 matrix. Since the mixing angle for only one sterile neutrino has been experimentally determined, we estimate the $ν$ to $e$ neutrino oscillation probability with different mixing angles for two of the sterile neutrinos.
hep-phInt.J.Theor.Phys.(2016)·2 citations
17*
Probing Pb+Pb collisions at $S_{N N} = 2760$ GeV with spectators
Vipul Bairathi🇮🇳 · Sandeep Chatterjee🇮🇳 · Md. Rihan Haque🇮🇳 · Bedangadas Mohanty🇮🇳
There is event by event geometric as well as quantum fluctuations in the initial condition of heavy-ion collisions. The standard technique of analysing heavy-ion collisions in bins of centrality obtained from final state multiplicity averages out the various initial configurations and thus restricts the study to only a limited range of initial conditions. In this paper, we propose an additional binning in terms of total spectator neutrons in an event. This offers us a key control parameter to probe events with broader range of initial conditions providing us an opportunity to peep into events with rarer initial conditions which otherwise get masked when analysed by centrality binning alone. We find that the inclusion of spectator binning allows one to vary $ε_{2}$ and $ε_{3}$ independently. We observe that the standard scaling relation between $v_{2} / ε_{2}$ and $\frac{1}{S} \frac{d N _{ch}}{d η}$ exhibited by centrality bins is broken by the spectator neutron bins. However, the acoustic scaling relation between $ln (v_{n} / ε_{n})$ and transverse system size holds for both centrality as well as spectator bins for central to mid-central collisions. The introduction of the spectator binning allows us to tune over a wide range viscosity driven effects for events with varying initial states but similar final state multiplicity.
↳ nucl-thhep-exhep-phnucl-exPLB(2016)·5 citations
18*
Strong diquark correlations inside the proton
Jorge Segovia🇪🇸
Quantum Chromodynamics is thought to be the relativistic quantum field theory that describes the strong interaction of the Standard Model. This interaction produces mesons but it is also able to generate quark-quark (diquark) correlations inside baryons. In this work, we employ a continuum approach to QCD based on Dyson-Schwinger equations to calculate the electromagnetic form factors of the proton and analyze in a deeper way the consequences of having strong diquark correlations. Comparison with the experimental data reveals that the presence of strong diquark correlations within the proton is sufficient to understand empirical extractions of the flavour-separated form factors. The explained reduction of the ratios $F_{1}^{d} / F_{1}^{u}$ and $F_{2}^{d} / F_{2}^{u}$ at high $Q^{2}$ in the quark-diquark picture are responsible of the precocious scaling of the $F_{2}^{p} / F_{1}^{p}$ observed experimentally.
↳ nucl-thhep-exhep-lathep-ph+1EPJ Web Conf.(2016)·0 citations
19*
Conserved Charge Susceptibilities in a Chemically Frozen Hadronic Gas
Jackson Ang'ong'a🇺🇸 · Todd Springer🇺🇸
In a hadronic gas with three conserved charges (electric charge, baryon number, and strangeness) we employ the hadron resonance gas model to compute both diagonal and off-diagonal susceptibilities. We model the effect of chemical freeze-out in two ways: one in which all particle numbers are conserved below the chemical freeze-out temperature and one which takes into account resonance decays. We then briefly discuss possible implications these results may have on two active areas of research, hydrodynamic fluctuations and the search for the QCD critical point.
↳ nucl-thhep-ph0 citations
20*
U(1) axial symmetry and Dirac spectra in QCD at high temperature
Takuya Kanazawa🇯🇵 · Naoki Yamamoto🇯🇵
We derive some exact results concerning the anomalous U(1) $_{A}$ symmetry in the chirally symmetric phase of QCD at high temperature. We discuss the importance of topology and finite-volume effects on the U(1) $_{A}$ symmetry violation characterized by the difference of chiral susceptibilities. In particular, we present a reliable method to measure the anomaly strength in lattice simulations with fixed topology. We also derive new spectral sum rules and a novel Banks-Casher-type relation. Through our spectral analysis we arrive at a simple alternative proof of the Aoki-Fukaya-Taniguchi "theorem" on the effective restoration of the U(1) $_{A}$ symmetry at high temperature.
↳ hep-thhep-lathep-phJHEP(2016)·39 citations
21*
Sensitivity of flow harmonics to sub-nucleon scale fluctuations in heavy ion collisions
Jacquelyn Noronha-Hostler (Columbia U.)🇺🇸 · Jorge Noronha (Sao Paulo U. & Columbia U.)🇧🇷 · Miklos Gyulassy (Columbia U.)🇺🇸
In this paper a new procedure to smooth out the initial energy densities of hydrodynamics is employed to show that the initial spatial eccentricities $ε_{m, n}$ , which drive the final state flow harmonics $v_{n}$ , are remarkably robust with respect to variations of the underlying scale of initial energy density spatial gradients, $λ$ , in nucleus-nucleus collisions. For $s = 2.76$ TeV Pb+Pb collisions, the $ε_{m, n}$ 's (across centrality classes) change by less than $10%$ if the scale of fluctuations is varied from $0.1$ to $1$ fm. We show, using the 2+1 Lagrangian hydrodynamic code, v-USPhydro, that this robustness is transferred to the final $v_{n}$ 's computed within event by event viscous hydrodynamics. This indicates that the flow harmonics in nucleus-nucleus collisions are not yet particularly sensitive to the underlying microscopic sub-nucleon physics below the confinement scale. On the other hand, the eccentricities of top $1%$ high multiplicity $s = 5.02$ TeV p+Pb collisions are found to be very sensitive to sub-nucleonic scale fluctuations, which should be contrasted with the robustness found in peripheral Pb+Pb collisions with the same multiplicity.
↳ nucl-thhep-phnucl-exPRC(2016)·84 citations
22*
Charge-Hyperscaling Violating Lifshitz hydrodynamics from black-holes
Elias Kiritsis🇫🇷 · Yoshinori Matsuo🇬🇷
Non-equilibrium black hole horizons are considered in scaling theories with generic Lifshitz invariance and an unbroken U(1) symmetry. There is also charge-hyperscaling violation associated with a non-trivial conduction exponent. The boundary stress tensor is computed and renormalized and the associated hydrodynamic equations derived. Upon a non-trivial redefinition of boundary sources associated with the U(1) gauge field, the equations are mapped to the standard non-relativistic hydrodynamics equations coupled to a mass current and an external Newton potential in accordance with the general theory of [arXiv:1502.00228]. The shear viscosity to entropy ratio is the same as in the relativistic case.
↳ hep-thhep-phJHEP(2015)·43 citations
23*
Sterile neutrinos with pseudoscalar self-interactions and cosmology
Maria Archidiacono🇩🇰 · Steen Hannestad🇩🇰 · Rasmus Sloth Hansen🇩🇰 · Thomas Tram🇬🇧
Sterile neutrinos in the electronvolt mass range are hinted at by a number of terrestrial neutrino experiments. However, such neutrinos are highly incompatible with data from the Cosmic Microwave Background and large scale structure. This paper discusses how charging sterile neutrinos under a new pseudoscalar interaction can reconcile eV sterile neutrinos with terrestrial neutrino data. We show that this model can reconcile eV sterile neutrinos in cosmology, providing a fit to all available data which is way better than the standard $Λ$ CDM model with one additional fully thermalized sterile neutrino. In particular it also prefers a value of the Hubble parameter much closer to the locally measured value.
↳ astro-ph.COhep-phPRD(2016)·52 citations
24*
New sum rule for the nuclear magnetic polarizability
Mikhail Gorchtein🇩🇪
I extend the well-known photonuclear sum rule that relates the strength of the photoexcitation of the giant dipole resonance in a nucleus to the number of elementary scatterers-nucleons to the case of virtual photons. The new sum rule relates the size of the magnetic polarizability of a nucleus to the slope of the transverse virtual photoabsorption cross section integrated over the energy in the nuclear range. I check this sum rule for the deuteron where necessary data is available, discuss possible applications and connection with other sum rules postulated in the literature.
↳ nucl-thhep-phnucl-exPRL(2015)·8 citations
25*
Quasinormal ringing on the brane
Hyeyoun Chung🇺🇸 · Lisa Randall🇺🇸 · Maria J. Rodriguez🇺🇸 · Oscar Varela🇺🇸
While the linear behavior of gravity in braneworld models is well understood, much less is known about full non-linear gravitational effects. Even when they agree at the linear level, these could be expected to distinguish braneworlds from a lower-dimensional theory with no brane. Black holes are a good testing ground for such studies, as they are nonlinear solutions that would be expected to reflect the background geometry. In particular, we assess the role of black hole quasinormal modes in gravitational experiments devised to be sensitive to the existence of the brane, in a lower-dimensional setting where we have analytical control. We compute quasinormal modes of brane-localized black holes and find that they follow the entropy of the corresponding black hole. This observation allows us to conclude that, surprisingly, the scattering problem we consider, at least in some regimes, does not distinguish between non-linear gravitational effects of black holes in AdS space with a brane and black holes in a spacetime of one lower dimension.
↳ hep-thgr-qchep-phClass.Quant.Grav.(2016)·13 citations
26*
Confinement--deconfinement phase transition and gauge-invariant gluonic mass in Yang-Mills theory
Kei-Ichi Kondo🇯🇵
We give an analytical derivation of the confinement/deconfinement phase transition at finite temperature in the $S U (N)$ Yang-Mills theory in the $D$ -dimensional space time for $D > 2$ . We elucidate what is the mechanism for quark confinement and deconfinement at finite temperature and why the phase transition occurs at a certain temperature. For this purpose, we use a novel reformulation of the Yang-Mills theory which allows the gauge-invariant gluonic mass term and calculate analytically the effective potential of the Polyakov loop average concretely for the $S U (2)$ and $S U (3)$ Yang-Mills theories by including the gauge-invariant dynamical gluonic mass. For $D = 4$ , we give an estimate on the transition temperature $T_{d}$ as the ratio to the gauge-invariant gluonic mass $M$ which has been measured on the lattice at zero temperature and is calculable also at finite temperature. We show that the order of the phase transition at $T_{d}$ is the second order for $S U (2)$ and weakly first order for $S U (3)$ Yang-Mills theory. These initial results are obtained easily based on the analytical calculations of the "one-loop type" in the first approximation. Then these results are identified with the initial condition in solving the flow equation of the Wetterich type to improve the initial results in a systematic way in the framework of the functional renormalization group. But the improvements do not change the initial results in an essential way except for some thermodynamic observables. We argue how the artifacts in the first approximation are eliminated to obtain the correct behaviors for such thermodynamic observables.
↳ hep-thhep-ph21 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.