118585263
Azimuthal correlations in Pb--Pb and pp collisions measured with the ALICE detector
We present results from the measurements of azimuthal correlations of charged particles in $\sqrt{s_{_{NN}}}$ = 2.76 TeV Pb--Pb collisions and $\sqrt{s_{_{NN}}}$ = 7 TeV pp collisions. In addition, the comparison of the experimental measurements in pp collisions with those from Pythia and Phojet simulations are presented.
118388670
Generic framework for anisotropic flow analyses with multiparticle azimuthal correlations
We present a new generic framework which enables exact and fast evaluation of all multi-particle azimuthal correlations. The framework can be readily used along with a correction framework for systematic biases in anisotropic flow analyses due to various detector inefficiencies. A new recursive algorithm has been developed for higher order correlators for the cases where their direct implementation is not feasible. We propose and discuss new azimuthal observables for anisotropic flow analyses which can be measured for the first time with our new framework. Effects of finite detector granularity on multi-particle correlations are quantified and discussed in detail. We point out the existence of a systematic bias in traditional differential flow analyses which stems solely from the applied selection criteria on particles used in the analyses, and is also present in the ideal case when only flow correlations are present. Finally, we extend the applicability of our generic framework to the case of differential multi-particle correlations.
119300824
Higher harmonic anisotropic flow measurements of charged particles at 2.76 TeV with the ALICE detector
We report the measurements of elliptic flow $v_{2}$, as well as higher harmonics triangular flow $v_{3}$ and quadrangular flow $v_{4}$, in $\sqrt{s_{_{NN}}} =$ 2.76 TeV Pb--Pb collisions, measured with the ALICE detector. We show that the measured elliptic and triangular flow can be understood from the initial spatial anisotropy and its event--by--event fluctuations. The resulting fluctuations of $v_{2}$ and $v_{3}$ are also discussed.
119117650
Anisotropic flow of identified particles in Pb--Pb collisions at $\sqrt{s_{_{\rm NN}}} =$ 2.76 TeV with the ALICE detector
The measurement of anisotropic flow of identified particles, including charged pion, kaon, (anti-)proton as well as strange and multi-strange particles (${\rm K_{S}^{0}}$, ${\rm \Lambda}$, ${\rm \Xi}$ and ${\rm \Omega}$) are measured in Pb--Pb collisions at $\sqrt{s_{_{{\rm NN}}}}$ = 2.76 TeV with the ALICE detector. The results are compared to measurements at RHIC and hydrodynamic model calculations. The mass splitting and the scaling with the number of constituent quarks of the anisotropic flow are also discussed.
119355833
Isospin relation and SU(3) breaking effects of strong phases in charmless B decays
Isospin and flavor SU(3) relations in charmless hadronic B decays B→ ππ, πK are investigated in detail with paying attention to the SU(3) symmetry breaking effects in both amplitudes and strong phases. In general, the isospin and the flavor SU(3) structure of the effective Hamiltonian provide several relations among the amplitudes and strong phases. Whereas a global fit to the latest data shows that some relation seems not to be favorable for a consistent explanation to the current data within the standard model (SM). By considering several patterns of SU(3) breaking, the amplitudes and the corresponding strong phases are extracted and compared with the theoretical estimations. It is found that in the case of SU(3) limits and also the case with SU(3) breaking only in amplitudes, the fitting results lead to an unexpected large ratio between two isospin amplitudes ac3/2/au3/2, which is about an order of magnitude larger than the SM prediction. The results are found to be insensitive to the weak phase γ. By including SU(3) breaking effects on the strong phases, one is able to obtain a consistent fit to the current data within the SM, which implies that the SU(3) breaking effect on strong phases may play an important role in understanding the observed charmless hadronic B decay modes B→ ππ and πK. It is possible to test those breaking effects in the near future from more precise measurements of direct CP violation in B factories. PACS: 13.25.Hw – 11.30.Er – 12.15.Hh – 12.60.Fr
119257921
Geometry of the effective Majorana neutrino mass in the $0\nu\beta\beta$ decay
The neutrinoless double-beta (0 nu beta beta) decay is a unique process used to identify the Majorana nature of massive neutrinos, and its rate depends on the size of the effective Majorana neutrino mass (ee). We put forward a novel 'coupling-rod' diagram to describe (ee) in the complex plane, by which the effects of the neutrino mass ordering and CP-violating phases on (ee) are intuitively understood. We show that this geometric language allows us to easily obtain the maximum and minimum of vertical bar (ee)vertical bar. It remains usable even if there is a kind of new physics contributing to (ee), and it can also be extended to describe the effective Majorana masses (e mu), (e tau), (mu mu), (mu tau), and (tau tau) which may appear in some other lepton-number violating processes.
53143868
N=4$$ \mathcal{N}=4 $$ Super-Yang-Mills on conic space as hologram of STU topological black hole
A bstractWe construct four-dimensional N=4$$ \mathcal{N}=4 $$ super-Yang-Mills theories on a conic sphere with various background R-symmetry gauge fields. We study free energy and supersymmetric Rényi entropy using heat kernel method as well as localization technique. We find that the universal contribution to the partition function in the free field limit is the same as that in the strong coupling limit, which implies that it may be protected by supersymmetry. Based on the fact that, the conic sphere can be conformally mapped to S1×ℍ3$$ {\mathbb{S}}^1\times {\mathrm{\mathbb{H}}}^3 $$ and the R-symmetry background fields can be supported by the R-charges of black hole, we propose that the holographic dual of these theories are five-dimensional, supersymmetric STU topological black holes. We demonstrate perfect agreement between N=4$$ \mathcal{N}=4 $$ super-Yang-MillstheoriesintheplanarlimitandtheSTUtopologicalblackholes.
119286757
Dirac neutrinos with S"4 flavor symmetry in warped extra dimensions
We present a warped extra dimension model with the custodial symmetry SU(2)(L) x SU(2)(R) x U(1)(X) x P-LR based on the flavor symmetry S-4 X Z(2) x Z(2)', and the neutrinos are taken to be Dirac particles. At leading order, the democratic lepton mixing is derived exactly, and the high-dimensional operators introduce corrections of order lambda(c) to all the three lepton mixing angles such that agreement with the experimental data can be achieved. The neutrino mass spectrum is predicted to be of the inverted hierarchy and the second octant of theta(23) is preferred. We suggest the modified democratic mixing, which is obtained by permuting the second and the third rows of the democratic mixing matrix, should be a good first order approximation to understanding sizable theta(13) and the first octant of theta(23). The constraints on the model from the electroweak precision measurements are discussed. Furthermore, we investigate the lepton mixing patterns for all the possible residual symmetries G(nu) and G(l) in the neutrino and charged lepton sectors, respectively. (C) 2013 Elsevier B.V. All rights reserved.
118464754
Exploration of decaying dark matter in a left-right symmetric model
SU(2)(L) triplet scalars appear in models motivated for the left-right symmetry, neutrino masses, and dark matter (DM), etc. If the triplets are the main decay products of the DM particle, and carry nonzero lepton numbers, they may decay dominantly into lepton pairs, which can naturally explain the current experimental results reported by PAMELA and Fermi-LAT or ATIC. We discuss this possibility in an extended left-right symmetric model in which the decay of the DM particle is induced by tiny soft charge-conjugation (C) violating interactions, and calculate the spectra for cosmic-ray positrons, neutrinos, and gamma rays. We show that the DM signals in the flux of high energy neutrinos can be significantly enhanced, as the triplets couple to both charged leptons and neutrinos with the same strength. In this scenario, the predicted neutrino-induced muon flux can be several times larger than the case in which the DM particle only directly decays into charged leptons. In addition, the charged components of the triplet may give an extra contribution to the high energy gamma rays through an internal bremsstrahlung process, which depends on the mass hierarchy between the DM particle and the triplet scalars.