Leading order covariant chiral nucleon-nucleon interaction
Ren, Xiu-Lei; Geng, Li-Sheng; Long, Bing-Wei; Ring, Peter; Meng, Jie
2016-01-01
Motivated by the successes of relativistic theories in studies of atomic/molecular and nuclear systems and the strong need for a covariant chiral force in relativistic nuclear structure studies, we develop a new covariant scheme to construct the nucleon-nucleon interaction in the framework of chiral effective field theory. The chiral interaction is formulated up to leading order with a covariant power counting and a Lorentz invariant chiral Lagrangian. We find that the covariant scheme induces all the six invariant spin operators needed to describe the nuclear force, which are also helpful to achieve cutoff independence for certain partial waves. A detailed investigation of the partial wave potentials shows a better description of the scattering phase shifts with low angular momenta than the leading order Weinberg approach. Particularly, the description of the $^1S_0$, $^3P_0$, and $^1P_1$ partial waves is similar to that of the next-to-leading order Weinberg approach. Our study shows that the relativistic fr...
Improved chiral nucleon-nucleon potential up to next-to-next-to-next-to-leading order
Epelbaum, E.; Krebs, H. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Bochum (Germany); Meissner, U.G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Forschungszentrum Juelich, Institut fuer Kernphysik, Institute for Advanced Simulation, and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, JARA - High Performance Computing, Juelich (Germany)
2015-05-15
We present improved nucleon-nucleon potentials derived in chiral effective field theory up to next-to-next-to-next-to-leading order. We argue that the nonlocal momentum-space regulator employed in the two-nucleon potentials of previous works (Nucl. Phys. A 747, 362 (2005) and Phys. Rev. C 68, 041001 (2003)) is not the most efficient choice, in particular since it affects the long-range part of the interaction. We are able to significantly reduce finite-cutoff artefacts by using an appropriate regularization in coordinate space which maintains the analytic structure of the amplitude. The new potentials do not require the additional spectral function regularization employed in (Nucl. Phys. A 747, 362 (2005)) to cut off the short-range components of the two-pion exchange and make use of the low-energy constants c{sub i} and d{sub i} determined from pion-nucleon scattering without any fine tuning. We discuss in detail the construction of the new potentials and convergence of the chiral expansion for two-nucleon observables. We also employ a simple approach for estimating the theoretical uncertainty in few-nucleon calculations from the truncation of the chiral expansion that replaces previous reliance on cutoff variation. (orig.)
Improved chiral nucleon-nucleon potential up to next-to-next-to-next-to-leading order
Epelbaum, E; Meißner, U -G
2014-01-01
We present improved nucleon-nucleon potentials derived in chiral effective field theory up to next-to-next-to-next-to-leading order. We argue that the nonlocal momentum-space regulator employed in the two-nucleon potentials of Refs. [E. Epelbaum, W. Gloeckle, U.-G. Mei{\\ss}ner, Nucl. Phys. A747 (2005) 362], [D.R. Entem, R. Machleidt, Phys. Rev. C68 (2003) 041001] is not the most efficient choice, in particular since it affects the long-range part of the interaction. We are able to significantly reduce finite-cutoff artefacts by using an appropriate regularization in coordinate space which maintains the analytic structure of the amplitude. The new potentials do not require the additional spectral function regularization employed in Ref. [E. Epelbaum, W. Gloeckle, U.-G. Mei{\\ss}ner, Nucl. Phys. A747 (2005) 362] to cut off the short-range components of the two-pion exchange and make use of the low-energy constants c_i and d_i determined from pion-nucleon scattering without any fine tuning. We discuss in detail t...
Filin, A A; Epelbaum, E; Hanhart, C; Krebs, H; Kudryavtsev, A E; Myhrer, F
2012-01-01
A complete calculation of the pion-nucleon loops that contribute to the transition operator for $NN\\to NN\\pi$ up-to-and-including next-to-next-to-leading order (N$^2$LO) in chiral effective field theory near threshold is presented. The evaluation is based on the so-called momentum counting scheme, which takes into account the relatively large momentum of the initial nucleons inherent in pion-production reactions. We show that the significant cancellations between the loops found at next-to-leading order (NLO) in the earlier studies are also operative at N$^2$LO. In particular, the $1/m_N$ corrections (with $m_N$ being the nucleon mass) to loop diagrams cancel at N$^2$LO, as do the contributions of the pion loops involving the low-energy constants $c_i$, i=1...4. In contrast to the NLO calculation however, the cancellation of loops at N$^2$LO is incomplete, yielding a non-vanishing contribution to the transition amplitude. Together with the one-pion exchange tree-level operators, the loop contributions provide...
Peripheral nucleon-nucleon scattering at fifth order of chiral perturbation theory
Entem, D R; Machleidt, R; Nosyk, Y
2014-01-01
We present the two- and three-pion exchange contributions to the nucleon-nucleon interaction which occur at next-to-next-to-next-to-next-to-leading order (N4LO, fifth order) of chiral effective field theory, and calculate nucleon-nucleon scattering in peripheral partial waves with L>=3 using low-energy constants that were extracted from pi-N analysis at fourth order. While the net three-pion exchange contribution is moderate, the two-pion exchanges turn out to be sizeable and prevailingly repulsive, thus, compensating the excessive attraction characteristic for NNLO and N3LO. As a result, the N4LO predictions for the phase shifts of peripheral partial waves are in very good agreement with the data (with the only exception of the 1F3 wave). We also discuss the issue of the order-by-order convergence of the chiral expansion for the NN interaction.
Chiral Symmetry and the Nucleon-Nucleon Interaction
Ruprecht Machleidt
2016-04-01
Full Text Available We review how nuclear forces emerge from low-energy quantum chromodynamics (QCD via chiral effective field theory (EFT. During the past two decades, this approach has evolved into a powerful tool to derive nuclear two- and many-body forces in a systematic and model-independent way. We then focus on the nucleon-nucleon (N N interaction and show in detail how, governed by chiral symmetry, the long- and intermediate-range of the N N potential builds up order by order. We proceed up to sixth order in small momenta, where convergence is achieved. The final result allows for a full assessment of the validity of the chiral EFT approach to the N N interaction.
Krebs, H; Meissner, U G; Epelbaum, Evgeny; Krebs, Hermann; Mei{\\ss}ner, Ulf-G.
2007-01-01
We study the two-nucleon force at next-to-next-to-leading order in a chiral effective field theory with explicit Delta degrees of freedom. Fixing the appearing low-energy constants from a next-to-leading order calculation of pion-nucleon threshold parameters, we find an improved convergence of most peripheral nucleon-nucleon phases compared to the theory with pions and nucleons only. In the delta-full theory, the next-to-leading order corrections are dominant in most partial waves considered.
Precision nucleon-nucleon potential at fifth order in the chiral expansion
Epelbaum, E; Meißner, U -G
2014-01-01
We present a nucleon-nucleon potential at fifth order in chiral effective field theory. We find a substantial improvement in the description of nucleon-nucleon phase shifts as compared to the fourth-order results of Ref. [E. Epelbaum, H. Krebs, U.-G. Mei{\\ss}ner, arXiv:1412.0142 [nucl-th
Peripheral nucleon-nucleon scattering at fifth order of chiral perturbation theory
Entem, D. R.; Kaiser, N.; Machleidt, R.; Nosyk, Y.
2015-01-01
We present the two- and three-pion-exchange contributions to the nucleon-nucleon interaction which occur at next-to-next-to-next-to-next-to-leading order (N4LO , fifth order) of chiral effective field theory and calculate nucleon-nucleon scattering in peripheral partial waves with L ≥3 by using low-energy constants that were extracted from π N analysis at fourth order. While the net three-pion-exchange contribution is moderate, the two-pion exchanges turn out to be sizable and prevailingly repulsive, thus compensating the excessive attraction characteristic for next-to-next-to-leading order and N3LO . As a result, the N4LO predictions for the phase shifts of peripheral partial waves are in very good agreement with the data (with the only exception being the 1F3 wave). We also discuss the issue of the order-by-order convergence of the chiral expansion for the N N interaction.
Comparison between chiral and meson-theoretic nucleon-nucleon potentials through (p,p') reactions
Sammarruca, F; Stephenson, E J
2002-01-01
We use proton-nucleus reaction data at intermediate energies to test the emerging new generation of chiral nucleon-nucleon (NN) potentials. Predictions from a high quality one-boson-exchange (OBE) force are used for comparison and evaluation. Both the chiral and OBE models fit NN phase shifts accurately, and the differences between the two forces for proton-induced reactions are small. A comparison to a chiral model with a less accurate NN description sets the scale for the ability of such models to work for nuclear reactions.
Chiral nucleon-nucleon forces in nuclear structure calculations
Coraggio L.
2016-01-01
Full Text Available Realistic nuclear potentials, derived within chiral perturbation theory, are a major breakthrough in modern nuclear structure theory, since they provide a direct link between nuclear physics and its underlying theory, namely the QCD. As a matter of fact, chiral potentials are tailored on the low-energy regime of nuclear structure physics, and chiral perturbation theory provides on the same footing two-nucleon forces as well as many-body ones. This feature fits well with modern advances in ab-initio methods and realistic shell-model. Here, we will review recent nuclear structure calculations, based on realistic chiral potentials, for both finite nuclei and infinite nuclear matter.
Chiral nucleon-nucleon forces in nuclear structure calculations
Coraggio, L; Holt, J W; Itaco, N; Machleidt, R; Marcucci, L E; Sammarruca, F
2016-01-01
Realistic nuclear potentials, derived within chiral perturbation theory, are a major breakthrough in modern nuclear structure theory, since they provide a direct link between nuclear physics and its underlying theory, namely the QCD. As a matter of fact, chiral potentials are tailored on the low-energy regime of nuclear structure physics, and chiral perturbation theory provides on the same footing two-nucleon forces as well as many-body ones. This feature fits well with modern advances in ab-initio methods and realistic shell-model. Here, we will review recent nuclear structure calculations, based on realistic chiral potentials, for both finite nuclei and infinite nuclear matter.
The nucleon-nucleon interaction up to sixth order in the chiral expansion
Machleidt, Ruprecht; Nosyk, Yevgen
2016-09-01
We have calculated the nucleon-nucleon potential up to sixth order (N5LO) of chiral perturbation theory. Previous calculations extended only up to N3LO (fourth order) and typically showed a surplus of attraction, particularly, when the π- N LECs from π- N analysis were applied consistently. Furthermore, the contributions at N2LO and N3LO are both fairly sizeable, thus, raising concerns about the convergence of the chiral expansion. We show that the N4LO contribution is repulsive and, essentially, cancels the excessive attraction of N3LO. The N5LO contribution turns out to be considerably smaller than the N4LO one, hence establishing the desired trend of convergence. The predictions at N5LO are in excellent agreement with the empirical phase shifts of peripheral partial waves. Supported by the US Department of Energy under Grant No. DE-FG02-03ER41270.
Few-nucleon systems with state-of-the-art chiral nucleon-nucleon forces
Binder, S; Epelbaum, E; Furnstahl, R J; Golak, J; Hebeler, K; Kamada, H; Krebs, H; Langhammer, J; Liebig, S; Maris, P; Meißner, U -G; Minossi, D; Nogga, A; Potter, H; Roth, R; Skibinski, R; Topolnicki, K; Vary, J P; Witala, H
2015-01-01
We apply improved nucleon-nucleon potentials up to fifth order in chiral effective field theory, along with a new analysis of the theoretical truncation errors, to study nucleon-deuteron (Nd) scattering and selected low-energy observables in 3H, 4He, and 6Li. Calculations beyond second order differ from experiment well outside the range of quantified uncertainties, providing truly unambiguous evidence for missing three-nucleon forces within the employed framework. The sizes of the required three-nucleon force contributions agree well with expectations based on Weinberg's power counting. We identify the energy range in elastic Nd scattering best suited to study three-nucleon force effects and estimate the achievable accuracy of theoretical predictions for various observables.
The Nucleon-Nucleon Interaction in a Chiral Constituent Quark Model
Stancu, F; Glozman, L Ya; Stancu, Fl.
1997-01-01
We study the short-range nucleon-nucleon interaction in a chiral constituent quark model by diagonalizing a Hamiltonian comprising a linear confinement and a Goldstone boson exchange interaction between quarks. The six-quark harmonic oscillator basis contains up to two excitation quanta. We show that the highly dominant configuration is $\\mid s^4p^2[42]_O [51]_{FS}>$ due to its specific flavour-spin symmetry. Using the Born-Oppenheimer approximation we find a strong effective repulsion at zero separation between nucleons in both $^3S_1$ and $^1S_0$ channels. The symmetry structure of the highly dominant configuration implies the existence of a node in the S-wave relative motion wave function at short distances. The amplitude of the oscillation of the wave function at short range will be however strongly suppressed. We discuss the mechanism leading to the effective short-range repulsion within the chiral constituent quark model as compared to that related with the one-gluon exchange interaction.
Navratil, P; Caurier, E
2003-10-14
The authors calculate properties of A = 6 system using the accurate charge-dependent nucleon-nucleon (NN) potential at fourth order of chiral perturbation theory. By application of the ab initio no-core shell model (NCSM) and a variational calculation in the harmonic oscillator basis with basis size up to 16 {h_bar}{Omega} they obtain the {sup 6}Li binding energy of 28.5(5) MeV and a converged excitation spectrum. Also, they calculate properties of {sup 10}B using the same NN potential in a basis space of up to 8 {h_bar}{Omega}. The results are consistent with results obtained by standard accurate NN potentials and demonstrate a deficiency of Hamiltonians consisting of only two-body terms. At this order of chiral perturbation theory three-body terms appear. It is expected that inclusion of such terms in the Hamiltonian will improve agreement with experiment.
Chiral effective field theory on the lattice at next-to-leading order
Borasoy, Bugra; Krebs, Hermann; Lee, Dean; Meißner, Ulf-G
2007-01-01
We study nucleon-nucleon scattering on the lattice at next-to-leading order in chiral effective field theory. We determine phase shifts and mixing angles from the properties of two-nucleon standing waves induced by a hard spherical wall in the center-of-mass frame. At fixed lattice spacing we test model independence of the low-energy effective theory by computing next-to-leading-order corrections for two different leading-order lattice actions. The first leading-order action includes instantaneous one-pion exchange and same-site contact interactions. The second leading-order action includes instantaneous one-pion exchange and Gaussian-smeared interactions. We find that in each case the results at next-to-leading order are accurate up to corrections expected at higher order.
Two-pion exchange nucleon-nucleon potential: relativistic chiral expansion
Higa, R
2003-01-01
We present a relativistic procedure for the chiral expansion of the two-pion exchange component of the $NN$ potential, which emphasizes the role of intermediate $\\pi N$ subamplitudes. The relationship between power counting in $\\pi N$ and $NN$ processes is discussed and results are expressed directly in terms of observable subthreshold coefficients. Interactions are determined by one and two-loop diagrams, involving pions, nucleons and other degrees of freedom, frozen into empirical subthreshold coefficients. The full evaluation of these diagrams produces amplitudes containing many different loop integrals. Their simplification by means of relations among these integrals leads to a set of intermediate results. Subsequent truncation to $O(q^4)$ yields the relativistic potential, which depends on five loop integrals, representing bubble, triangle, crossed box and box diagrams. The bubble and triangle integrals are the same as in $\\pi N$ scattering and we have shown that they also determine the chiral structures...
Bayesian truncation errors in chiral effective field theory: Nucleon-nucleon observables
Melendez, J. A.; Wesolowski, S.; Furnstahl, R. J.
2017-08-01
Chiral effective field theory (EFT) predictions are necessarily truncated at some order in the EFT expansion, which induces an error that must be quantified for robust statistical comparisons to experiment. In previous work, a Bayesian model for truncation errors of perturbative expansions was adapted to EFTs. The model yields posterior probability distribution functions (pdfs) for these errors based on expectations of naturalness encoded in Bayesian priors and the observed order-by-order convergence pattern of the EFT. A first application was made to chiral EFT for neutron-proton scattering using the semilocal potentials of Epelbaum, Krebs, and Meißner (EKM). Here we extend this application to consider a larger set of regulator parameters, energies, and observables as a general example of a statistical approach to truncation errors. The Bayesian approach allows for statistical validations of the assumptions and enables the calculation of posterior pdfs for the EFT breakdown scale. The statistical model is validated for EKM potentials whose convergence behavior is not distorted by regulator artifacts. For these cases, the posterior for the breakdown scale is consistent with EKM assumptions.
Time-reversal-invariance-violating nucleon-nucleon potential in the 1/N_c expansion
Samart, Daris; Schindler, Matthias R; Phillips, Daniel R
2016-01-01
We apply the large-$N_c$ expansion to the time-reversal-invariance-violating (TV) nucleon-nucleon potential. The operator structures contributing to next-to-next-to-leading order in the large-$N_c$ counting are constructed. For the TV and parity-violating case we find a single operator structure at leading order. The TV but parity-conserving potential contains two leading-order terms, which however are suppressed by 1/$N_c$ compared to the parity-violating potential. Comparison with phenomenological potentials, including the chiral EFT potential in the TV parity-violating case, leads to large-$N_c$ scaling relations for TV meson-nucleon and nucleon-nucleon couplings.
Szpigel, S. [Centro de Ciencias e Humanidades, Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil); Timoteo, V.S. [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP (Brazil); Duraes, F. de O [Centro de Ciencias e Humanidades, Universidade Presbiteriana Mackenzie, Sao Paulo, SP (Brazil)
2010-02-15
In this work we study the Similarity Renormalization Group (SRG) evolution of effective nucleon-nucleon (NN) interactions derived using the Subtracted Kernel Method (SKM) approach. We present the results for the phaseshifts in the {sup 1}S{sub 0} channel calculated using a SRG potential evolved from an initial effective potential obtained by implementing the SKM scheme for the leading-order NN interaction in chiral effective field theory (ChEFT).
Filin, A A; Epelbaum, E; Hanhart, C; Krebs, H; Myhrer, F
2013-01-01
A calculation of the pion-production operator up to next-to-next-to-leading order for s-wave pions is performed within chiral effective field theory. In the previous study [Phys. Rev. C 85, 054001 (2012)] we discussed the contribution of the pion-nucleon loops at the same order. Here we extend that study to include explicit Delta degrees of freedom and the 1/m_N^2 corrections to the pion-production amplitude. Using the power counting scheme where the Delta-nucleon mass difference is of the order of the characteristic momentum scale in the production process, we calculate all tree-level and loop diagrams involving Delta up to next-to-next-to-leading order. The long-range part of the Delta loop contributions is found to be of similar size to that from the pion-nucleon loops which supports the counting scheme. The net effect of pion-nucleon and Delta loops is expected to play a crucial role in understanding of the neutral pion production data.
Dilute neutron matter on the lattice at next-to-leading order in chiral effective field theory
Borasoy, Bugra; Krebs, Hermann; Lee, Dean; Meißner, Ulf-G
2007-01-01
We discuss lattice simulations of the ground state of dilute neutron matter at next-to-leading order in chiral effective field theory. In a previous paper the coefficients of the next-to-leading-order lattice action were determined by matching nucleon-nucleon scattering data for momenta up to the pion mass. Here the same lattice action is used to simulate the ground state of up to 12 neutrons in a periodic cube using Monte Carlo. We explore the density range from 2% to 8% of normal nuclear density and analyze the ground state energy as an expansion about the unitarity limit with corrections due to finite scattering length, effective range, and P-wave interactions.
Nucleon-nucleon scattering in the 1S0 partial wave in the modified Weinberg approach
Gasparyan A. M.
2016-01-01
Full Text Available Nucleon-nucleon scattering in the 1S0 partial wave is considered in chiral effective field theory within the recently suggested renormalizable formulation based on the Kadyshevsky equation. Contact interactions are taken into account beyond the leading-order approximation. The subleading contact terms are included non-perturbatively by means of subtractive renormalization. The dependence of the phase shifts on the choice of the renormalization condition is discussed. Perturbative inclusion of the subleading contact interaction is found to be justified only very close to threshold. The low-energy theorems are reproduced significantly better compared with the leading order results.
Induced Hyperon-Nucleon-Nucleon Interactions and the Hyperon Puzzle
Wirth, Roland
2016-01-01
We present the first ab initio calculations for $p$-shell hypernuclei including hyperon-nucleon-nucleon (YNN) contributions induced by a Similarity Renormalization Group transformation of the initial hyperon-nucleon interaction. The transformation including the YNN terms conserves the spectrum of the Hamiltonian while drastically improving model-space convergence of the Importance-Truncated No-Core Shell Model, allowing a precise extraction of binding and excitation energies. Results using a hyperon-nucleon interaction at leading order in chiral effective field theory for lower- to mid-$p$-shell hypernuclei show a good reproduction of experimental excitation energies while hyperon binding energies are typically overestimated. The induced YNN contributions are strongly repulsive and we show that they are related to a decoupling of the $\\Sigma$ hyperons from the hypernuclear system, i.e., a suppression of the $\\Lambda$-$\\Sigma$ conversion terms in the Hamiltonian. This is linked to the so-called hyperon puzzle ...
$^1S_0$ nucleon-nucleon scattering in the modified Weinberg approach
Epelbaum, E; Gegelia, J; Krebs, H
2015-01-01
Nucleon-nucleon scattering in the $^1S_0$ partial wave is considered in chiral effective field theory within the renormalizable formulation of Ref. [1] beyond the leading-order approximation. By applying subtractive renormalization, the subleading contact interaction in this channel is taken into account non-perturbatively. For a proper choice of renormalization conditions, the predicted energy dependence of the phase shift and the coefficients in the effective range expansion are found to be in a good agreement with the results of the Nijmegen partial wave analysis.
{sup 1}S{sub 0} nucleon-nucleon scattering in the modified Weinberg approach
Epelbaum, E.; Krebs, H. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Fakultaet fuer Physik und Astronomie, Bochum (Germany); Gasparyan, A.M. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Fakultaet fuer Physik und Astronomie, Bochum (Germany); SSC RF ITEP, Moscow (Russian Federation); Gegelia, J. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Fakultaet fuer Physik und Astronomie, Bochum (Germany); Tbilisi State University, Tbilisi (Georgia)
2015-06-15
Nucleon-nucleon scattering in the {sup 1}S{sub 0} partial wave is considered in chiral effective field theory within the renormalizable formulation of a previous work (Phys. Lett. B 716, 338 (2012)) beyond the leading-order approximation. By applying subtractive renormalization, the subleading contact interaction in this channel is taken into account non-perturbatively. For a proper choice of renormalization conditions, the predicted energy dependence of the phase shift and the coefficients in the effective range expansion are found to be in a good agreement with the results of the Nijmegen partial wave analysis. (orig.)
Nucleon-nucleon theory and phenomenology
Signell, P.
1981-03-01
This project involves five inter-related subprojects: (1) derivation of the intermediate range nucleon-nucleon interaction using a new method that utilizes much shorter and simpler analytic continuation through the unphysical region that lies between the ..pi..N and ..pi pi.. physical regions of the N anti N ..-->.. ..pi pi.. amplitude (with significantly improved accuracy for the nucleon-nucleon interaction); (2) construction of a short range phenomenological potential that, with the theoretical part mentioned above, gives a precise fit to the nucleon-nucleon data and is parameterized for easy use in nucleon calculations; (3) phase shift analyses of the world data below 400 MeV, especially the large amount of very precise data below 20 MeV and the new data near 55 MeV that have never been analyzed properly; (4) the introduction of a K-matrix formulation of the Optimal Polynomial Expansion in order to accelerate convergence of the partial wave series at LAMPF energies; and (5) setting up of a cooperatively evaluated permanent nucleon-nucleon data bank in the 0-1200 MeV range that can be used by all nucleon-nucleon reseachers.
Study of nucleon-nucleon and hyperon-nucleon interaction
Shimizu, Kiyotaka [Department of Physics, Sophia University, Tokyo (Japan); Takeuchi, Sachiko [Japan College of Social Work, Kiyose (Japan); Buchmann, A.J. [Institute for Theoretical Physics, University of Tuebinge (Germany)
2000-04-01
In this paper we review recent investigations of nucleon-nucleon and hyperon-nucleon interactions employing a non-relativistic quark cluster model. We concentrate mainly on the short and medium-range behavior of the baryon-baryon interaction based on the one-gluon and meson exchange potentials. The chiral quark model based on pion and sigma exchange between quarks is also discussed. We also review a study of the deuteron and its electromagnetic properties in a quark model with exchange currents. (author)
Central Nucleon-Nucleon Potential
Robilotta, M. R.
2001-12-01
The outer region of the NN interactions is dominated by the one pion exchange potential (OPEP), followed by the two-pion exchange potential (TPEP). Chiral calculations of the TPEP have been performed using either heavy baryon1 (HB) or relativistic2 perturbation theories. We compare the predictions from these two approaches for the dominant central interaction and show that they fail to agree by 25% ...
Three-pion exchange a gap in the nucleon-nucleon potential
Pupin, J C
1999-01-01
The leading contribution to the three-pion exchange nucleon-nucleon potential is calculated in the framework of chiral symmetry. It has pseudoscalar and axial components and is dominated by the former, which has a range of about 1.5 fm and tends to enhance the OPEP. The strength of this force does not depend on the pion mass and hence it survives in the chiral limit.
Leading-order nuclear π-γ exchange force
Friar, J. L.; Coon, S. A.
1996-02-01
The leading-order isospin-violating force from simultaneous π and γ exchange is calculated. The charge-symmetric, but charge-dependent, force is calculated for static nucleons and in Coulomb gauge. Infrared divergences and other technical problems are discussed. The resulting force is roughly 3 orders of magnitude smaller than OPEP and roughly the same size as the Breit correction to single-photon exchange. The present calculation corresponds to a subset of one-loop diagrams in chiral perturbation theory for isospin violation in the nucleon-nucleon force.
Brazilian relativistic O(q**4) two-pion exchange nucleon nucleon potential: Parametrized version
C.A. da Rocha; R. Higa; M.R. Robilotta
2007-03-01
In our recent works we derived a chiral O(q4) two-pion exchange nucleon-nucleon potential (TPEP) formulated in a relativistic baryon (RB) framework, expressed in terms of the so called low energy constants (LECs) and functions representing covariant loop integrations. In order to facilitate the use of the potential in nuclear applications, we present a parametrized version of our configuration space TPEP.
Two-pion exchange nucleon-nucleon potential Model independent features
Robilotta, Manoel R.; da Rocha, Carlos A.
1997-02-01
A chiral pion-nucleon amplitude supplemented by the HJS subthreshold coefficients is used to calculate the the long range part of the two-pion exchange nucleon-nucleon potential. In our expressions the HJS coefficients factor out, allowing a clear identification of the origin of the various contributions. A discussion of the configuration space behaviour of the loop integrals that determine the potential is presented, with emphasis on cancellations associated with chiral symmetry. The profile function for the scalar-isoscalar component of the potential is produced and shown to disagree with those of several semi-phenomenological potentials.
Comparing Some Nucleon-Nucleon Potentials
Naghdi, M
2013-01-01
The aim is to compare a few Nucleon-Nucleon (NN) potentials especially Reid68, Reid68-Day, Reid93, UrbanaV14, ArgonneV18, Nijmegen 93, Nijmegen I, Nijmegen II. Although these potentials have some likenesses and are almost phenomenological, they include in general different structures and its own characteristics. The potentials are constructed in a manner that fit the NN scattering data or phase shifts and are compared in this way. A high-quality scale of a potential is that it fits the data with $\\chi^{2}/N_{data} \\approx 1$, describes well deuteron properties or gives satisfactory results in nuclear structure calculations. However, these scales have some failures. Here, we first compare many potentials by confronting with data. Then, we try to compare the potential forms by considering the potential structures directly and therefore regarding their substantial basis somehow. On the other hand, since the potentials are written in different schema, it is necessary to write the potentials in a unique schema to ...
Lattice Simulations for Light Nuclei: Chiral Effective Field Theory at Leading Order
Borasoy, B; Krebs, H; Lee, D; Meißner, Ulf G; Borasoy, Bugra; Epelbaum, Evgeny; Krebs, Hermann; Lee, Dean; Mei{\\ss}ner, Ulf-G.
2006-01-01
We discuss lattice simulations of light nuclei at leading order in chiral effective field theory. Using lattice pion fields and auxiliary fields, we include the physics of instantaneous one-pion exchange and the leading-order S-wave contact interactions. We also consider higher-derivative contact interactions which adjust the S-wave scattering amplitude at higher momenta. By construction our lattice path integral is positive definite in the limit of exact Wigner SU(4) symmetry for any even number of nucleons. This SU(4) positivity and the approximate SU(4) symmetry of the low-energy interactions play an important role in suppressing sign and phase oscillations in Monte Carlo simulations. We assess the computational scaling of the lattice algorithm for light nuclei with up to eight nucleons and analyze in detail calculations of the deuteron, triton, and helium-4.
Baryon chiral perturbation theory up to next-to-leading order
Bos, J W; Lee, S C; Lin, Y C; Shih, H H; Bos, J W; Chang, D W; Lee, S C; Lin, Y C; Shih, H H
1995-01-01
We examine the general lagrangian for baryon chiral perturbation theory with SU(3) flavor symmetry, up to the next-to-leading order. We consider both the strong and the weak interaction. The inverse of the baryon mass is treated as an additional small expansion parameter, and heavy fermion effective field theory techniques are employed to provide a consistent expansion scheme. A detailed account is given on the restrictions imposed on the lagrangian by the various symmetries. Corrections due to the finite baryon mass are also discussed.
General aspects of the nucleon-nucleon interaction and nuclear matter properties
Plohl, Oliver
2008-07-25
The subject of the present thesis is at first the investigation of model independent properties of the nucleon-nucleon (NN) interaction in the vacuum concerning the relativistic structure and the implications for nuclear matter properties. Relativistic and non-relativistic meson-exchange potentials, phenomenological potentials s well as potentials based on effective field theory (EFT) are therefore mapped on a relativistic operator basis given by the Clifford Algebra. This allows to compare the various approaches at the level of covariant amplitudes where a remarkable agreement is found. Furthermore, the relativistic self-energy is determined in the Hartree-Fock (HF) approximation. The appearance of a scalar and vector field of several hundred MeV magnitude is a general feature of relativistic descriptions of nuclear matter. Within QCD sum rules these fields arise due to the density dependence of chiral condensates. We find that independent of the applied NN interaction large scalar and vector fields are generated when the symmetries of the Lorentz group are restored. In the framework of chiral EFT (chEFT) it is shown, that these fields are generated by short-range next-to-leading order (NLO) contact terms, which are connected to the spin-orbit interaction. To estimate the effect arising from NN correlations the equation of state of nuclear and neutron matter is calculated in the Brueckner-HF (BHF) approximation applying chEFT. Although, as expected, a clear over-binding is found (at NLO a saturating behavior is observed), the symmetry energy shows realistic properties when compared to phenomenological potentials (within the same approximation) and other approaches. The investigation of the pion mass dependence within chEFT at NLO shows that the magnitude of the scalar and vector fields persists in the chiral limit - nuclear matter is still bound. In contrast to the case of a pion mass larger than the physical one the binding energy and saturation density are
Nucleon-nucleon resonances at intermediate energies using a complex energy formalism
Papadimitriou, G
2015-01-01
We apply our method of complex scaling, valid for a general class of potentials, in a search for nucleon-nucleon S-matrix poles up to 2 GeV laboratory kinetic energy. We find that the realistic potentials JISP16, constructed from inverse scattering, and chiral field theory potentials N$^3$LO and N$^2$LO$_{opt}$ support resonances in energy regions well above their fit regions. In some cases these resonances have widths that are narrow when compared with the real part of the S-matrix pole.
A novel nuclear dependence of nucleon-nucleon short-range correlations
Dai, Hongkai; Huang, Yin; Chen, Xurong
2016-01-01
A linear correlation is found between the magnitude of nucleon-nucleon short-range correlations and the nuclear binding energy per nucleon with pairing energy removed. By using this relation, the strengths of nucleon-nucleon short-range correlations of some unmeasured nuclei are predicted. Discussions on nucleon-nucleon pairing energy and nucleon-nucleon short-range correlations are made. The found nuclear dependence of nucleon-nucleon short-range correlations may shed some lights on the short-range structure of nucleus.
Complete next-to-next-to-leading order calculation of NN → NNπ in chiral effective field theory
Filin A. A.
2014-01-01
Full Text Available We present the results of the pion production operator calculated up-to-and-including next-to-next-to-leading order (NNLO in chiral effective field theory. We include explicit Delta degrees of freedom and demonstrate that they provide essential contribution required to understand neutral pion production data. Analysis of chiral loops at NNLO reveals new mechanisms which are important, but haven’t been considered in phenomenological studies so far.
Statistical Error analysis of Nucleon-Nucleon phenomenological potentials
Perez, R Navarro; Arriola, E Ruiz
2014-01-01
Nucleon-Nucleon potentials are commonplace in nuclear physics and are determined from a finite number of experimental data with limited precision sampling the scattering process. We study the statistical assumptions implicit in the standard least squares fitting procedure and apply, along with more conventional tests, a tail sensitive quantile-quantile test as a simple and confident tool to verify the normality of residuals. We show that the fulfilment of normality tests is linked to a judicious and consistent selection of a nucleon-nucleon database. These considerations prove crucial to a proper statistical error analysis and uncertainty propagation. We illustrate these issues by analyzing about 8000 proton-proton and neutron-proton scattering published data. This enables the construction of potentials meeting all statistical requirements necessary for statistical uncertainty estimates in nuclear structure calculations.
The electric dipole form factor of the nucleon in chiral perturbation theory to sub-leading order
Mereghetti, E.; de Vries, J.; Hockings, W. H.; Maekawa, C. M.; van Kolck, U.
2011-01-01
The electric dipole form factor (EDFF) of the nucleon stemming from the QCD (theta) over bar term and from the quark color-electric dipole moments is calculated in chiral perturbation theory to sub-leading order. This is the lowest order in which the isoscalar EDFF receives a calculable, non-analyti
Nucleon-nucleon collision profile and cross section fluctuations
Rybczynski, Maciej
2013-01-01
The nucleon-nucleon collision profile, being the basic entity of the wounded nucleon model, is usually adopted in the form of hard sphere or the Gaussian shape. We suggest that the cross section fluctuations given by the gamma distribution leads to the profile function which smoothly ranges between the both limiting forms. Examples demonstrating sensitivity of profile function on cross section fluctuations are discussed.
Nucleon-Nucleon Scattering From Fully-Dynamical Lattice QCD
Konstantinos Orginos; Martin Savage; Paulo Bedaque; Silas Beane
2006-07-01
We present results of the first fully-dynamical lattice QCD determination of nucleon-nucleon scattering lengths in the 1 S0 channel and 3 S1 - 3 D1 coupled channels. The calculations are performed with domain-wall valence quarks on the MILC staggered configurations with lattice spacing of b = 0.125 fm in the isospin-symmetric limit, and in the absence of electromagnetic interactions
Epelbaum, Evgeny; Lee, Dean; Meißner, Ulf-G
2008-01-01
We present lattice calculations for the ground state energy of dilute neutron matter at next-to-leading order in chiral effective field theory. This study follows a series of recent papers on low-energy nuclear physics using chiral effective field theory on the lattice. In this work we introduce an improved spin- and isospin-projected leading-order action which allows for a perturbative treatment of corrections at next-to-leading order and smaller estimated errors. Using auxiliary fields and Euclidean-time projection Monte Carlo, we compute the ground state of 8, 12, and 16 neutrons in a periodic cube, covering a density range from 2% to 10% of normal nuclear density.
The Anapole Moment of the Deuteron with the Argonne v18 Nucleon-Nucleon Interaction Model
Hyun, C H; Hyun, Chang Ho; Desplanques, Bertrand
2003-01-01
We calculate the deuteron anapole moment with the wave functions obtained from the Argonne $v18$ nucleon-nucleon interaction model. The anapole moment operators are considered at the leading order. To minimize the uncertainty due to a lack of current conservation, we calculate the matrix element of the anapole moment from the original definition. In virtue of accurate wave functions, we can obtain a more precise value of the deuteron anapole moment which contains less uncertainty than the former works. We obtain a result reduced by more than 25% in the magnitude of the deuteron anapole moment. The reduction of individual nuclear contributions is much more important however, varying from a factor 2 for the spin part to a factor 4 for the convection and associated two-body currents.
A Quark Transport Theory to describe Nucleon--Nucleon Collisions
Kalmbach, U; Biro, T S; Mosel, U
1993-01-01
On the basis of the Friedberg-Lee model we formulate a semiclassical transport theory to describe the phase-space evolution of nucleon-nucleon collisions on the quark level. The time evolution is given by a Vlasov-equation for the quark phase-space distribution and a Klein-Gordon equation for the mean-field describing the nucleon as a soliton bag. The Vlasov equation is solved numerically using an extended testparticle method. We test the confinement mechanism and mean-field effects in 1+1 dimensional simulations.
Nucleon-nucleon scattering from effective field theory
Kaplan, D B; Wise, M B; Kaplan, David B; Savage, Martin J; Wise, Mark B
1996-01-01
We perform a nonperturbative calculation of the 1S0 nucleon-nucleon scattering amplitude, using an effective field theory (EFT) expansion. We use dimensional regularization throughout, and the MS-bar renormalization scheme; our final result depends only on physical observables. We show that the EFT expansion of the real part of the inverse of the Feynman amplitude converges at momenta much greater than the scale that characterizes the derivative expansion of the EFT Lagrangian. Our conclusions are optimistic about the applicability of an EFT approach to the quantitative study of nuclear matter.
Leading-order decuplet contributions to the baryon magnetic moments in chiral perturbation theory
Geng, L.S. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, 46071-Valencia (Spain); Camalich, J. Martin [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, 46071-Valencia (Spain)], E-mail: camalich@ific.uv.es; Vacas, M.J. Vicente [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, 46071-Valencia (Spain)
2009-06-01
We extend an earlier study of the baryon magnetic moments in chiral perturbation theory by the explicit inclusion of the spin-3/2 decuplet resonances. We find that the corrections induced by these heavier degrees of freedom are relatively small in a covariant framework where unphysical spin-1/2 modes are removed. Consequently, implementing the leading SU(3)-breaking corrections given by both the baryon and decuplet contributions, we obtain a description of the baryon-octet magnetic moments that is better than the Coleman-Glashow relations. Finally, we discuss the uncertainties and compare between heavy baryon and covariant approaches.
Leading-order decuplet contributions to the baryon magnetic moments in Chiral Perturbation Theory
Geng, L S; Vacas, M J Vicente
2009-01-01
We extend an earlier study of the baryon magnetic moments in chiral perturbation theory by the explicit inclusion of the spin-3/2 decuplet resonances. We find that the corrections induced by these heavier degrees of freedom are relatively small in a covariant framework where unphysical spin-1/2 modes are removed. Consequently, implementing the leading SU(3)-breaking corrections given by both the baryon and decuplet contributions, we obtain a description of the baryon-octet magnetic moments that is better than the Coleman-Glashow relations. Finally, we discuss the uncertainties and compare between heavy baryon and covariant approaches.
Petschauer S.
2014-06-01
Full Text Available In this proceeding results for hyperon-nucleon interactions calculated at next-to-leading order (i.e. one-loop order in SU(3 chiral effective field theory are presented. The potentials include contributions from one- and two-meson exchange, and four-baryon contact terms provided by the SU(3 chiral Lagrangian. SU(3 flavor symmetry is imposed for the low-energy constants, while explicit SU(3 symmetry breaking is included only through the physical pseudoscalar-meson and baryon masses. Calculations have been performed for hyperon-nucleon scattering cross sections using a regularized Lippmann-Schwinger equation. A good description of the available data is achieved, comparable to modern phenomenological hyperon-nucleon interaction models. These results provide a new basis for studies of hypernuclei or hyperons in nuclear matter.
Lattice chiral effective field theory with three-body interactions at next-to-next-to-leading order
Epelbaum, Evgeny; Lee, Dean; Meißner, Ulf-G
2009-01-01
We consider low-energy nucleons at next-to-next-to-leading order in lattice chiral effective field theory. Three-body interactions first appear at this order, and we discuss several methods for determining three-body interaction coefficients on the lattice. We compute the energy of the triton and low-energy neutron-deuteron scattering phase shifts in the spin-doublet and spin-quartet channels using Luescher's finite volume method. In the four-nucleon system we calculate the energy of the alpha particle using auxiliary fields and projection Monte Carlo.
Nucleon-Nucleon Scattering in a Three Dimensional Approach
Fachruddin, I; Glöckle, W; Elster, Ch.
2000-01-01
The nucleon-nucleon (NN) t-matrix is calculated directly as function of two vector momenta for different realistic NN potentials. To facilitate this a formalism is developed for solving the two-nucleon Lippmann-Schwinger equation in momentum space without employing a partial wave decomposition. The total spin is treated in a helicity representation. Two different realistic NN interactions, one defined in momentum space and one in coordinate space, are presented in a form suited for this formulation. The angular and momentum dependence of the full amplitude is studied and displayed. A partial wave decomposition of the full amplitude it carried out to compare the presented results with the well known phase shifts provided by those interactions.
Open and Hidden Strangeness Production in Nucleon-Nucleon Collisions
Shyam, Radhey
2008-01-01
We present an overview of the description of K and eta meson productions in nucleon-nucleon collisions within an effective Lagrangian model where meson production proceeds via excitation, propagation and subsequent decay of intermediate baryonic resonant states. The $K$ meson contains a strange quark ($s$) or antiquark ($\\bar s$) while the $\\eta$ meson has hidden strangeness as it contains some component of the $s{\\bar s}$ pair. Strange meson production is expected to provide information on the manifestation of quantum chromodynamics in the non-perturbative regime of energies larger than that of the low energy pion physics. We discuss specific examples where proper understanding of the experimental data for these reactions is still lacking.
Study of Z boson production in PbPb collisions at nucleon-nucleon centre of mass energy = 2.76 TeV
Chatrchyan, S. [Yerevan Physics Institute (Aremenia); et al.,
2011-05-01
A search for Z bosons in the mu^+mu^- decay channel has been performed in PbPb collisions at a nucleon-nucleon centre of mass energy = 2.76 TeV with the CMS detector at the LHC, in a 7.2 inverse microbarn data sample. The number of opposite-sign muon pairs observed in the 60--120 GeV/c^2 invariant mass range is 39, corresponding to a yield per unit of rapidity (y) and per minimum bias event of (33.8 +/- 5.5 (stat) +/- 4.4 (syst)) 10^{-8}, in the |y|<2.0 range. Rapidity, transverse momentum, and centrality dependencies are also measured. The results agree with next-to-leading order QCD calculations, scaled by the number of incoherent nucleon-nucleon collisions.
Hyun, Chang Ho; Lee, Hee-Jung
2016-01-01
We investigate the parity-violating pion-nucleon-nucleon coupling constant $h^1_{\\pi NN}$, based on the chiral quark-soliton model. We employ an effective weak Hamiltonian that takes into account the next-to-leading order corrections from QCD to the weak interactions at the quark level. Using the gradient expansion, we derive the leading-order effective weak chiral Lagrangian with the low-energy constants determined. The effective weak chiral Lagrangian is incorporated in the chiral quark-soliton model to calculate the parity-violating $\\pi NN$ constant $h^1_{\\pi NN}$. We obtain a value of about $10^{-7}$ at the leading order. The corrections from the next-to-leading order reduce the leading order result by about 20~\\%.
Dispersion relations in application to chiral two-nucleon dynamics
Gasparyan A.M.
2014-06-01
Full Text Available A novel scheme based on the chiral Lagrangian is applied to the nucleon-nucleon interaction close to threshold. Subthreshold partial-wave amplitudes are calculated in chiral perturbation theory and analytically extrapolated above threshold. The constraints imposed by analyticity and unitarity are used to stabilize the extrapolation. A reasonable description of the empirical phase shifts up to laboratory energies Tlab ≃ 300 MeV is obtained in terms of the parameters relevant at next-to-next-to-next-to-leading order. The convergence properties of the method and the comparison with the conventional potential approach are discussed.
Database of Nucleon-Nucleon Scattering Cross Sections by Stochastic Simulation Project
National Aeronautics and Space Administration — A database of nucleon-nucleon elastic differential and total cross sections will be generated by stochastic simulation of the quantum Liouville equation in the...
Quantum Monte Carlo calculations with chiral effective field theory interactions.
Gezerlis, A; Tews, I; Epelbaum, E; Gandolfi, S; Hebeler, K; Nogga, A; Schwenk, A
2013-07-19
We present the first quantum Monte Carlo (QMC) calculations with chiral effective field theory (EFT) interactions. To achieve this, we remove all sources of nonlocality, which hamper the inclusion in QMC calculations, in nuclear forces to next-to-next-to-leading order. We perform auxiliary-field diffusion Monte Carlo (AFDMC) calculations for the neutron matter energy up to saturation density based on local leading-order, next-to-leading order, and next-to-next-to-leading order nucleon-nucleon interactions. Our results exhibit a systematic order-by-order convergence in chiral EFT and provide nonperturbative benchmarks with theoretical uncertainties. For the softer interactions, perturbative calculations are in excellent agreement with the AFDMC results. This work paves the way for QMC calculations with systematic chiral EFT interactions for nuclei and nuclear matter, for testing the perturbativeness of different orders, and allows for matching to lattice QCD results by varying the pion mass.
Dai, Ling-Yun; Haidenbauer, Johann; Meißner, Ulf-G.
2017-07-01
Results for the antinucleon-nucleon (\\overline{N}N) interaction obtained at next-to-next-to-next-to-leading order in chiral effective field theory (EFT) are reported. A new local regularization scheme is used for the pion-exchange contributions that has been recently suggested and applied in a pertinent study of the N N force within chiral EFT. Furthermore, an alternative strategy for estimating the uncertainty is utilized that no longer depends on a variation of the cutoffs. The low-energy constants associated with the arising contact terms are fixed by a fit to the phase shifts and inelasticities provided by a phase-shift analysis of \\overline{p}p scattering data. An excellent description of the \\overline{N}N amplitudes is achieved at the highest order considered. Moreover, because of the quantitative reproduction of partial waves up to J = 3, there is also a nice agreement on the level of \\overline{p}p observables. Specifically, total and integrated elastic and charge-exchange cross sections agree well with the results from the partial-wave analysis up to laboratory energies of 300 MeV, while differential cross sections and analyzing powers are described quantitatively up to 200-250 MeV. The low-energy structure of the \\overline{N}N amplitudes is also considered and compared to data from antiprotonic hydrogen.
The parity-violating nucleon-nucleon force in the 1/N_c expansion
Phillips, Daniel R; Schat, Carlos
2014-01-01
Several experimental investigations have observed parity violation in nuclear systems-a consequence of the weak force between quarks. We apply the $1/N_c$ expansion of QCD to the P-violating T-conserving component of the nucleon-nucleon (NN) potential. We show there are two leading-order operators, both of which affect $\\vec{p}p$ scattering at order $N_c$. We find an additional four operators at $O(N_c^0 \\sin^2 \\theta_W)$ and six at $O(1/N_c)$. Pion exchange in the PV NN force is suppressed by $1/N_c$ and $\\sin^2 \\theta_W$, providing a quantitative explanation for its non-observation up to this time. The large-$N_c$ hierarchy of other PV NN force mechanisms is consistent with estimates of the couplings in phenomenological models. The PV observed in $\\vec{p}p$ scattering data is compatible with natural values for the strong and weak coupling constants: there is no evidence of fine tuning.
Hammer events, neutrino energies, and nucleon-nucleon correlations
Weinstein, L B; Piasetzky, E
2016-01-01
Neutrino oscillation measurements depend on a difference between the rate of neutrino-nucleus interactions at different neutrino energies or different distances from the source. Knowledge of the neutrino energy spectrum and neutrino-detector interactions are crucial for these experiments. Short range nucleon-nucleon correlations in nuclei (SRC) affect properties of nuclei. The ArgoNeut liquid Argon Time Projection Chamber (lArTPC) observed neutrino-argon scattering events with two protons back-to-back in the final state ("hammer" events) which they associated with SRC pairs. The MicroBoone lArTPC will measure far more of these events. We simulate hammer events using two simple models. We use the well-known electron-nucleon cross section to calculate e-argon interactions where the e- scatters from a proton, ejecting a pi+, and the pi+ is then absorbed on a moving deuteron-like $np$ pair. We also use a model where the electron excites a nucleon to a Delta, which then deexcites by interacting with a second nucle...
Nuclear effects on neutrino emissivities from nucleon-nucleon bremsstrahlung
Stoica, S.; Paun, V. P.; Negoita, A. G.
2004-06-01
The rates of neutrino pair emission by nucleon-nucleon (NN) bremsstrahlung are calculated with the inclusion of the full contribution from a nuclear one pion exchange potential (OPEP). We compute the contributions from the neutron-neutron (nn), proton-proton (pp), and neutron-proton (np) processes for physical conditions encountered in supernovae and neutron stars, both in the degenerate (D) and nondegenerate (ND) limits. We find a significant reduction of these rates, especially for the nn and pp processes, in comparison with the case when the whole nuclear contribution was replaced by constants, representing the high-momentum limits of the expressions of the nuclear potential. Furthermore, we also perform the calculations by including contributions due to the ρ meson exchange between nucleons, in the OPEP. This may be relevant for processes produced in the inner core of neutron stars, where the density may exceed several times the standard nuclear density, and the short-range part of the NN interaction should be taken into account. These corrections lead to an additional suppression of the neutrino emission rates between (8 and 36)%, depending on the process [nn (pp) or np] and physical conditions (temperature and degeneracy of the nucleons).
Haidenbauer, J.; Meißner, Ulf-G.; Petschauer, S.
2016-10-01
The strangeness S = - 2 baryon-baryon interaction is studied in chiral effective field theory up to next-to-leading order. The potential at this order consists of contributions from one- and two-pseudoscalar-meson exchange diagrams and from four-baryon contact terms without and with two derivatives. SU(3) flavor symmetry is imposed for constructing the interaction in the S = - 2 sector. Specifically, the couplings of the pseudoscalar mesons to the baryons are fixed by SU(3) symmetry and, in general, also the contact terms are related via SU(3) symmetry to those determined in a previous study of the S = - 1 hyperon-nucleon interaction. The explicit SU(3) symmetry breaking due to the physical masses of the pseudoscalar mesons (π, K, η) is taken into account. It is argued that the ΞN interaction has to be relatively weak to be in accordance with available experimental constraints. In particular, the published values and upper bounds for the Ξ- p elastic and inelastic cross sections apparently rule out a somewhat stronger attractive ΞN force and, specifically, disfavor any near-threshold deuteron-like bound states in that system.
Magas, V K; Ramos, A
2013-01-01
The meson-baryon interactions in s-wave in the strangeness S=-1 sector are studied using a chiral unitarity approach based on the next-to-leading order chiral SU(3) Lagrangian. The model is fitted to the large set of experimental data in different two-body channels. Particular attention is paid to the $\\Xi$ hyperon production reaction, $\\bar{K} N \\rightarrow K \\Xi$, where the effect of the next-to-leading order terms in the Lagrangian play a crucial role, since the cross section of this reaction at tree level is zero.
Low-energy NN scattering with a Brazilian chiral potential
Batista, E.F. [Universidade Estadual do Sudoeste da Bahia (UESB), Vitoria da Conquista, BA (Brazil); Rocha, C.A. [Instituto Federal de Educacao, Ciencia e Tecnologia de Sao Paulo (IFSP), SP (Brazil); Szpigel, S. [Universidade Presbiteriana Mackenzie (UPM), SP (Brazil); Timoteo, V.S. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil)
2012-07-01
Full text: We apply the subtracted kernel method (SKM), a renormalization approach based on recursive multiple subtractions performed in the kernel of the scattering equation, to a Brazilian chiral nucleon-nucleon (NN) interactions up to next-to-next-to-next-to-leading-order (N3LO). We evaluate the phase shifts in the 1S0 and 3P0 channels and explicitly demonstrate that the SKM procedure is renormalization group invariant under the change of the subtraction scale through a non-relativistic Callan-Symanzik flow equation for the evolution of the renormalized NN interactions. (author)
Nucleon-nucleon interaction with one-pion exchange and instanton-induced interactions
Vanamali, C. S.; Kumar, K. B. Vijaya
2016-11-01
Singlet (S10) and triplet (S31) nucleon-nucleon potentials are obtained in the framework of the SU(2) nonrelativistic quark model using the resonating-group method in the Born-Oppenheimer approximation. The full Hamiltonian used in the investigation includes the kinetic energy, two-body confinement potential, one-gluon-exchange potential (OGEP), one-pion exchange potential (OPEP), and instanton induced interaction (III), which includes the effect of quark exchange between the nucleons. The contribution of the OGEP, III, and OPEP to the nucleon-nucleon adiabatic potential is discussed.
Lynn, J E
2015-01-01
I discuss our recent work on Green's function Monte Carlo (GFMC) calculations of light nuclei using local nucleon-nucleon interactions derived from chiral effective field theory (EFT) up to next-to-next-to-leading order (N$^2$LO). I present the natural extension of this work to include the consistent three-nucleon (3N) forces at the same order in the chiral expansion. I discuss our choice of observables to fit the two low-energy constants which enter in the 3N sector at N$^2$LO and present some results for light nuclei.
Lynn J. E.
2016-01-01
Full Text Available I discuss our recent work on Green’s function Monte Carlo (GFMC calculations of light nuclei using local nucleon-nucleon interactions derived from chiral effective field theory (EFT up to next-to-next-to-leading order (N2LO. I present the natural extension of this work to include the consistent three-nucleon (3N forces at the same order in the chiral expansion. I discuss our choice of observables to fit the two low-energy constants which enter in the 3N sector at N2LO and present some results for light nuclei.
Nucleon-Nucleon Phase Shifts in the Extended Quark-Delocalization Colour-Screening Model
LU Xi-Feng; PING Jia-Lun; WANG Fan
2003-01-01
An alternative method is applied to the study of nucleon-nucleon scattering phase shifts within the framework of the extended quark demoralization colour-screening model, in which the one-pion exchange with short-range cutoff is included.
SPHINX v 1.1 Monte Carlo Program for Polarized Nucleon-Nucleon Collisions (update)
Güllenstern, S; Górnicki, P; Mankiewicz, L; Schäfer, A; Güllenstern, Stefan; Martin, Oliver; Gornicki, Pawel; Mankiewicz, Lech; Schäfer, Andreas
1996-01-01
We present the updated long write-up for version 1.1 of the SPHINX Monte Carlo. The program can be used to simulate polarized nucleon - nucleon collisions at high energies. Spins of colliding particles are taken into account. The program allows the calculation of cross sections for various processes.
XING Yong-Zhong; HAO Huan-Feng; LIU Xiao-Bin; FANG Yu-Tian; LIU Bao-Yi
2007-01-01
@@ Influences of the isospin dependence of the in-medium nucleon-nucleon cross section and the momentum-dependent interaction (MDI) on the isotope scaling are investigated by using the isospin-dependent quantum molecular dynamics model (IQMD). The results show that both the isospin dependence of the in-medium nucleon-nucleon cross section and the momentum-dependent interaction affect the isoscaling parameters appreciably and independently. The influence caused by the isospin dependence of two-body collision is relatively larger than that from the MDI in the mean field. Aiming at exploring the implication of isoscaling behaviour, which the statistical equilibrium in the reaction is reached, the statistical properties in the mass distribution and the kinetic energy distribution of the fragments simulated by IQMD are presented.
FSI corrections for near threshold meson production in nucleon-nucleon collisions
Moalem, A; Gedalin, E
1995-01-01
A procedure is proposed which accounts for final state interaction corrections for near threshold meson production in nucleon-nucleon scattering. In analogy with the Watson-Migdal approximation, it is shown that in the limit of extremely strong final state effects, the amplitude factorizes into a primary production amplitude and an elastic scattering amplitude describing a 3 \\to 3 transition. This amplitude determines the energy dependence of the reaction cross section near the reaction threshold almost solely. The approximation proposed satisfies the Fermi-Watson theorem and the coherence formalism. Application of this procedure to meson production in nucleon-nucleon scattering shows that, while corrections due to the meson-nucleon interaction are small for s-wave pion production, they are crucial for reproducing the energy dependence of the \\eta production cross section.
Nucleon-nucleon scattering at small angles, measured at ANKE-COSY
Bagdasarian, Z.
2016-03-01
The most accepted approach to describe nucleon-nucleon (NN) interaction is the partial wave analysis (PWA), which translates various experimental observables to the common language of the partial waves. The reliable analysis relies not only on the quality experimental data, but also on the measurements of scattering observables over preferably the full angular range. Small angle scattering has been measured for six beam energies between 0.8 and 2.4 GeV using polarized proton beam incident on both proton and deuteron unpolarized targets at COSY-ANKE. This proceeding will report on the published and preliminary results for both pp and pn scattering from this and other recent experiments at ANKE. This study aims to provide the valuable observables to the SAID group in order to improve the phenomenological understanding of the nucleon-nucleon interaction.
Nuclear effects on axions emission rates from nucleon-nucleon bremsstrahlung
Pastrav, B.; Scafes, A. C.
2010-11-01
The rates of axion emissions by nucleon-nucleon bremsstrahlung from neutron stars obtained with the inclusion of the full angular momentum contribution from a nuclear one-pion-exchange potential (OPEP), are studied in different conditions of temperature and degeneracy in both, non degenerate (ND) and degenerate (D) regimes. The comparison with the previous results obtained in literature, where only the high momentum limit of the OPEP expressions are used, is done and the differences discussed.
Feijoo, A; Ramos, A
2015-01-01
The meson-baryon interaction in s-wave in the strangeness S=-1 sector has been studied, employing a chiral SU(3) Lagrangian up to next-to-leading order (NLO) and implementing unitarization in coupled channels. The parameters of the Lagrangian have been fitted to a large set of experimental data in different two-body channels, paying special attention to the $\\bar{K} N \\rightarrow K \\Xi$ reaction, which is particularly sensitive to the NLO terms. With the aim of improving the model in the $K\\Xi$ production channels, effects of the high spin hyperon resonances $\\Sigma(2030)$ and $\\Sigma(2250)$ have been taken into account phenomenologically.
The phase-functions method and full cross-section of nucleon-nucleon scattering
Zhaba, V I
2016-01-01
For calculation of the single-channel nucleon-nucleon scattering a phase-functions method has been considered. Using a phase-functions method the following phase shifts of a nucleon-nucleon scattering are calculated numerically: nn (1S0-, 3P0-, 3P1-, 1D2-, 3F3- state), pp (1S0-, 3P0-, 3P1-, 1D2- state) and np (1S0-, 1P1-, 3P0-, 3P1-, 1D2-, 3D2- state). The calculations has been performed using realistic nucleon-nucleon potentials Nijmegen groups (NijmI, NijmII, Reid93) and potential Argonne v18. Obtained phase shifts are in good agreement with the results obtained in the framework of other methods. Using the obtained phase shifts we have calculated the full cross-section. Our results are in good agreement with those obtained by using known phases published in literature. The odds between calculations depending on a computational method of phases of scattering makes: 0,2-6,3% for pp- and 0,1-5,3% for np- scatterings (NijmI, NijmII), 0,1-4,1% for pp- and 0,1-0,4% for np- scatterings (Reid93), no more than 4,5% ...
Probing short-range nucleon-nucleon interactions with an Electron-Ion Collider
Miller, Gerald A; Venugopalan, Raju
2015-01-01
We derive the cross-section for exclusive vector meson production in high energy deeply inelastic scattering off a deuteron target that disintegrates into a proton and a neutron carrying large relative momentum in the final state. This cross-section can be expressed in terms of a novel gluon Transition Generalized Parton Distribution (T-GPD); the hard scale in the final state makes the T-GPD sensitive to the short distance nucleon-nucleon interaction. We perform a toy model computation of this process in a perturbative framework and discuss the time scales that allow the separation of initial and final state dynamics in the T-GPD. We outline the more general computation based on the factorization suggested by the toy computation: in particular, we discuss the relative role of "point-like" and "geometric" Fock configurations that control the parton dynamics of short range nucleon-nucleon scattering. With the aid of exclusive $J/\\Psi$ production data at HERA, as well as elastic nucleon-nucleon cross-sections, w...
Sammarruca, Francesca
2013-01-01
After reviewing our microscopic approach to nuclear and neutron-rich matter, we focus on how nucleon-nucleon scattering is impacted by the presence of a dense hadronic medium, with special emphasis on the case where neutron and proton densities are different. We discuss in detail medium and isospin asymmetry effects on the total elastic cross section and the mean free path of a neutron or a proton in isospin-asymmetric nuclear matter. We point out that in-medium cross sections play an important role in heavy-ion simulations aimed at extracting constraints on the symmetry potential. We argue that medium and isospin dependence of microscopic cross sections are the results of a complex balance among various effects, and cannot be simulated with a simple phenomenological model.
Matching pion-nucleon Roy-Steiner equations to chiral perturbation theory
Hoferichter, Martin; Kubis, Bastian; Meißner, Ulf-G
2015-01-01
We match the results for the subthreshold parameters of pion-nucleon scattering obtained from a solution of Roy-Steiner equations to chiral perturbation theory up to next-to-next-to-next-to-leading order, to extract the pertinent low-energy constants including a comprehensive analysis of systematic uncertainties and correlations. We study the convergence of the chiral series by investigating the chiral expansion of threshold parameters up to the same order and discuss the role of the \\Delta(1232) resonance in this context. Results for the low-energy constants are also presented in the counting scheme usually applied in chiral nuclear effective field theory, where they serve as crucial input to determine the long-range part of the nucleon-nucleon potential as well as three-nucleon forces.
Matching Pion-Nucleon Roy-Steiner Equations to Chiral Perturbation Theory
Hoferichter, Martin; Ruiz de Elvira, Jacobo; Kubis, Bastian; Meißner, Ulf-G.
2015-11-01
We match the results for the subthreshold parameters of pion-nucleon scattering obtained from a solution of Roy-Steiner equations to chiral perturbation theory up to next-to-next-to-next-to-leading order, to extract the pertinent low-energy constants including a comprehensive analysis of systematic uncertainties and correlations. We study the convergence of the chiral series by investigating the chiral expansion of threshold parameters up to the same order and discuss the role of the Δ (1232 ) resonance in this context. Results for the low-energy constants are also presented in the counting scheme usually applied in chiral nuclear effective field theory, where they serve as crucial input to determine the long-range part of the nucleon-nucleon potential as well as three-nucleon forces.
Rozpedzik, D; Kolling, S; Epelbaum, E; Skibinski, R; Witala, H; Krebs, H
2011-01-01
The recently derived long-range two-pion exchange (TPE) contributions to the nuclear current operator which appear at next-to-leading order (NLO) of the chiral expansion are used to describe electromagnetic processes. We study their role in the photodisintegration of 2H and 3He and compare our predictions with experimental data. The bound and scattering states are calculated using five different parametrizations of the chiral next-to-next-to-leading order (N2LO) nucleon-nucleon (NN) potential which allows us to estimate the theoretical uncertainty at a given order in the chiral expansion. For some observables the results are very close to the predictions based on the AV18 NN potential and the current operator (partly) consistent with this force. In the most cases, the addition of long-range TPE currents improved the description of the experimental data.
Probing short-range nucleon-nucleon interactions with an electron-ion collider
Miller, Gerald A.; Sievert, Matthew D.; Venugopalan, Raju
2016-04-01
We derive the cross section for exclusive vector meson production in high-energy deeply inelastic scattering off a deuteron target that disintegrates into a proton and a neutron carrying large relative momentum in the final state. This cross section can be expressed in terms of a novel gluon transition generalized parton distribution (T-GPD); the hard scale in the final state makes the T-GPD sensitive to the short-distance nucleon-nucleon interaction. We perform a toy model computation of this process in a perturbative framework and discuss the time scales that allow the separation of initial- and final-state dynamics in the T-GPD. We outline the more general computation based on the factorization suggested by the toy computation: In particular, we discuss the relative role of "pointlike" and "geometric" Fock configurations that control the parton dynamics of short-range nucleon-nucleon scattering. With the aid of exclusive J /ψ production data at the Hadron-Electron Ring Accelerator at DESY, as well as elastic nucleon-nucleon cross sections, we estimate rates for exclusive deuteron photodisintegration at a future Electron-Ion Collider (EIC). Our results, obtained using conservative estimates of EIC integrated luminosities, suggest that center-of-mass energies sNN˜12 GeV2 of the neutron-proton subsystem can be accessed. We argue that the high energies of the EIC can address outstanding dynamical questions regarding the short-range quark-gluon structure of nuclear forces by providing clean gluon probes of such "knockout" exclusive reactions in light and heavy nuclei.
Dimensional versus cut-off renormalization and the nucleon-nucleon interaction
Ghosh, A; Talukdar, B; Ghosh, Angsula; Adhikari, Sadhan K.
1998-01-01
The role of dimensional regularization is discussed and compared with that of cut-off regularization in some quantum mechanical problems with ultraviolet divergence in two and three dimensions with special emphasis on the nucleon-nucleon interaction. Both types of renormalizations are performed for attractive divergent one- and two-term separable potentials, a divergent tensor potential, and the sum of a delta function and its derivatives. We allow energy-dependent couplings, and determine the form that these couplings should take if equivalence between the two regularization schemes is to be enforced. We also perform renormalization of an attractive separable potential superposed on an analytic divergent potential.
Dimensional versus cut-off renormalization and the nucleon-nucleon interaction
Ghosh, Angsula; Adhikari, Sadhan K.; Talukdar, B.
1998-10-01
The role of dimensional regularization is discussed and compared with that of cut-off regularization in some quantum mechanical problems with ultraviolet divergence in two and three dimensions with special emphasis on the nucleon-nucleon interaction. Both types of renormalizations are performed for attractive divergent one- and two-term separable potentials, a divergent tensor potential, and the sum of a delta function and its derivatives. We allow energy-dependent couplings, and determine the form that these couplings should take if equivalence between the two regularization schemes is to be enforced. We also perform renormalization of an attractive separable potential superposed on an analytic divergent potential.
The total nucleon-nucleon cross section at large N_c
Cohen, Thomas D
2012-01-01
It is shown that at sufficiently large $N_c$ for incident momenta which are much larger than the QCD, the total nucleon-nucleon cross section is independent of incident momentum and given by $\\sigma^{\\rm total}=2 \\pi \\log^2(N_c) / (m^2_{\\pi})$. This result is valid in the extreme large $N_c$ regime of $\\log(N_c) \\gg 1$ and has corrections of relative order $\\log (\\log(N_c))/\\log(N_c)$. A possible connection of this result to the Froissart-Martin bound is discussed.
Precise Determination of Charge Dependent Pion-Nucleon-Nucleon Coupling Constants
Perez, R Navarro; Arriola, E Ruiz
2016-01-01
We undertake a covariance error analysis of the pion-nucleon-nucleon coupling constants from the Granada-2013 np and pp database comprising a total of 6713 scattering data. Assuming a unique pion-nucleon coupling constant we obtain $f^2=0.0761(3)$. The effects of charge symmetry breaking on the $^3P_0$, $^3P_1$ and $^3P_2$ partial waves are analyzed and we find $f_{p}^2 = 0.0759(4)$, $f_{0}^2 = 0.079(1)$ and $f_{c}^2 = 0.0763(6)$ with minor correlations among the coupling constants. We successfully test normality for the residuals of the fit.
Navarro Pérez, R.; Amaro, J. E.; Ruiz Arriola, E.
2016-11-01
We analyze the low-energy nucleon-nucleon (NN) interaction by confronting statistical versus systematic uncertainties. This is carried out with the help of model potentials fitted to the Granada-2013 database where a statistically meaningful partial wave analysis comprising a total of 6713 np and pp published scattering data below 350 MeV from 1950 till 2013 has been made. We extract threshold parameter uncertainties from the coupled-channel effective range expansion up to j≤slant 5. We find that for threshold parameters systematic uncertainties are generally at least an order of magnitude larger than statistical uncertainties. Similar results are found for np phase shifts and amplitude parameters.
Partial-wave analysis of nucleon-nucleon elastic scattering data
Workman, Ron L.; Briscoe, William J.; Strakovsky, Igor I.
2016-12-01
Energy-dependent and single-energy fits to the existing nucleon-nucleon database have been updated to incorporate recent measurements. The fits cover a region from threshold to 3 GeV, in the laboratory kinetic energy, for proton-proton scattering, with an upper limit of 1.3 GeV for neutron-proton scattering. Experiments carried out at the COSY-WASA and COSY-ANKE facilities have had a significant impact on the partial-wave solutions. Results are discussed in terms of both partial-wave and direct reconstruction amplitudes.
Ladygina, N B
2008-01-01
The model suggested by Love and Franey for description of the nucleon-nucleon interaction was used as the base. The new fitting of the model parameters was done in the energy range from 100 MeV up to 1100 MeV. It is based on the modern partial-wave-analysis solution for NN-amplitudes. The three observables: differential cross section, vector analyzing power, and spin correlation coefficient -- were obtained at every energy. The results are compared with existing the experimental data.
Partial-Wave Analysis of Nucleon-Nucleon Elastic Scattering Data
Workman, Ron L; Strakovsky, Igor I
2016-01-01
Energy-dependent and single-energy fits to the existing nucleon-nucleon database have been updated to incorporate recent measurements. The fits cover a region from threshold to 3 GeV, in the laboratory kinetic energy, for proton-proton scattering, with an upper limit of 1.3 GeV for neutron-proton scattering. Experiments carried out at the COSY-WASA and COSY-ANKE facilities have had a significant impact on the partial-wave solutions. Results are discussed in terms of both partial-wave and direct reconstruction amplitudes.
Rybczyński, Maciej
2011-01-01
We investigate the influence of the nucleon-nucleon collision profile (probability of interaction as a function of the nucleon-nucleon impact parameter) in the wounded nucleon model and its extensions on several observables measured in relativistic heavy-ion collisions. We find that the participant eccentricity coefficient, $\\epsilon^\\ast$, as well as the higher harmonic coefficients, $\\epsilon_n^\\ast$, are reduced by 10-20% for mid-peripheral collisions when the realistic (Gaussian) profile is used, as compared to the case with the commonly-used hard-sphere profile. Similarly, the multiplicity fluctuations, treated as the function of the number of wounded nucleons in one of the colliding nuclei, are reduced by 10-20%. This demonstrates that the Glauber Monte Carlo codes should necessarily use the realistic nucleon-nucleon collision profile in precision studies of these observables. The Gaussian collision profile is built-in in {\\tt GLISSANDO}.
Extra dimensions, SN1987a, and nucleon-nucleon scattering data
Hanhart, C; Reddy, S; Savage, M J; Hanhart, Christoph; Phillips, Daniel R.; Reddy, Sanjay; Savage, Martin J.
2001-01-01
One of the strongest constraints on the existence of large, compact, "gravity-only" dimensions comes from SN1987a. If the rate of energy loss into these putative extra dimensions is too high, then the neutrino pulse from the supernova will differ from that actually seen. The dominant mechanism for the production of Kaluza-Klein gravitons and dilatons in the supernova is via gravistrahlung and dilastrahlung from the nucleon-nucleon system. In this paper we compute the rates for these processes in a model-independent way using low-energy theorems which relate the emissivities to the measured nucleon-nucleon cross section. This is possible because for soft gravitons and dilatons the leading contribution to the energy-loss rate is from graphs in which the gravitational radiation is produced from external nucleon legs. Previous calculations neglected these mechanisms. We re-evaluate the bounds on toroidally-compactified "gravity-only" dimensions (GODs), and find that consistency with the observed SN1987a neutrino ...
Collective multipole excitations based on correlated realistic nucleon-nucleon interactions
Paar, N. [Zagreb Univ. (Croatia). Fac. of Science, Physics Dept.; Papakonstantinou, P.; Hergert, H.; Roth, R. [Technische Univ. Darmstadt (Germany). Inst. fuer Kernphysik
2006-05-24
We investigate collective multipole excitations for closed shell nuclei from {sup 16}O to {sup 208}Pb using correlated realistic nucleon-nucleon interactions in the framework of the random phase approximation (RPA). The dominant short-range central and tensor correlations a re treated explicitly within the Unitary Correlation Operator Method (UCOM), which provides a phase-shift equivalent correlated interaction VUCOM adapted to simple uncorrelated Hilbert spaces. The same unitary transformation that defines the correlated interaction is used to derive correlated transition operators. Using VUCOM we solve the Hartree-Fock problem and employ the single-particle states as starting point for the RPA. By construction, the UCOM-RPA is fully self-consistent, i.e. the same correlated nucleon-nucleon interact ion is used in calculations of the HF ground state and in the residual RPA interaction. Consequently, the spurious state associated with the center-of-mass motion is properly removed and the sum-rules are exhausted within {+-}3%. The UCOM-RPA scheme results in a collective character of giant monopole, dipole, and quadrupole resonances in closed-shell nuclei across the nuclear chart. For the isoscalar giant monopole resonance, the resonance energies are in agreement with experiment hinting at a reasonable compressibility. However, in the 1{sup -} and 2{sup +} channels the resonance energies are overestimated due to missing long-range correlations and three-body contributions. (orig.)
A transport theory of relativistic nucleon-nucleon collisions with confinement
Vetter, T; Mosel, U
1994-01-01
A transport theory is developed on the quark level to describe nucleon--nucleon collisions. We treat the strong interaction effectively by the Friedberg-Lee model both in its original and in its modified confining version. First we study the stability of the static three-dimensional semiclassical configuration, then we present results of the time evolution given by a Vlasov equation for the quarks coupled to a Klein-Gordon equation for the mean field. We find at higher energies that the nucleons are almost transparent, whereas at lower energies we observe a substantial interaction. At very low energies we see a fusion of our bags, which is due to the purely attractive nature of the mean field and hence is an artifact of our model. We test the confinement mechanism and find that at higher energies the nucleons are restored shortly after the collision.
Skyrme-Model $\\pi NN$ Form Factor and Nucleon-Nucleon Interaction
Holzwarth, G
1997-01-01
We apply the strong $\\pi NN$ form factor, which emerges from the Skyrme model, in the two-nucleon system using a one-boson-exchange (OBE) model for the nucleon-nucleon (NN) interaction. Deuteron properties and phase parameters of NN scattering are reproduced well. In contrast to the form factor of monopole shape that is traditionally used in OBE models, the Skyrme form factor leaves low momentum transfers essentially unaffected while it suppresses the high-momentum region strongly. It turns out that this behavior is very appropriate for models of the NN interaction and makes possible to use a soft pion form factor in the NN system. As a consequence, the $\\pi N$ and the $NN$ systems can be described using the same soft $\\pi NN$ form factor, which is impossible with the monopole.
Impact of Nucleon-Nucleon Bremsstrahlung Rates Beyond One-Pion Exchange
Bartl, Alexander; Janka, Hans-Thomas; Schwenk, Achim
2016-01-01
Neutrino-pair production and annihilation through nucleon-nucleon bremsstrahlung is included in current supernova simulations by rates that are based on the one-pion-exchange approximation. Here we explore the consequences of bremsstrahlung rates based on a modern nuclear interactions for proto-neutron star cooling and the corresponding neutrino emission. We find that despite a reduction of the bremsstrahlung emission by a factor of 2-5 in the neutrinospheric region, models with the improved treatment exhibit only $\\lesssim$5% changes of the neutrino luminosities and an increase of $\\lesssim$0.7 MeV of the average energies of the radiated neutrino spectra, with the largest effects for the antineutrinos of all flavors and at late times. Overall, the proto-neutron star cooling evolution is slowed down modestly by $\\lesssim$0.5-1 s.
More on Heisenberg's model for high energy nucleon-nucleon scattering
Nastase, Horatiu
2015-01-01
We revisit Heisenberg's model for nucleon-nucleon scattering which admits a saturation of the Froissart bound. We examine its uniqueness, and find that up to certain natural generalizations, it is the only action that saturates the bound. We find that we can extract also sub-leading behaviour for $\\sigma_{\\rm tot}(s)$ from it, though that requires a knowledge of the wavefunction solution that is hard to obtain, and a black-disk model allows the calculation of $\\sigma_{elastic}(s)$ as well. The wavefunction solution is analyzed perturbatively, and its source is interpreted. Generalizations to several mesons, addition of vector mesons, and curved space regimes are also found. We discuss the relations between Heisenberg's model and holographic models that are dual to QCD-like theories.
Impact of nucleon-nucleon bremsstrahlung rates beyond one-pion exchange
Bartl, A.; Bollig, R.; Janka, H.-T.; Schwenk, A.
2016-10-01
Neutrino-pair production and annihilation through nucleon-nucleon bremsstrahlung is included in current supernova simulations by rates that are based on the one-pion-exchange approximation. Here we explore the consequences of bremsstrahlung rates based on modern nuclear interactions for proto-neutron star cooling and the corresponding neutrino emission. We find that despite a reduction of the bremsstrahlung emission by a factor of 2-5 in the neutrinospheric region, models with the improved treatment exhibit only ≲5 % changes of the neutrino luminosities and an increase of ≲0.7 MeV of the average energies of the radiated neutrino spectra, with the largest effects for the antineutrinos of all flavors and at late times. Overall, the proto-neutron star cooling evolution is slowed down modestly by ≲0.5 - 1 s .
Adam, J.; Tater, M.; Truhlík, E.; Epelbaum, E.; Machleidt, R.; Ricci, P.
2012-03-01
The doublet capture rate Λ1 / 2 of the negative muon capture in deuterium is calculated employing the nuclear wave functions generated from accurate nucleon-nucleon (NN) potentials constructed at next-to-next-to-next-to-leading order of heavy-baryon chiral perturbation theory and the weak meson exchange current operator derived within the same formalism. All but one of the low-energy constants that enter the calculation were fixed from pion-nucleon and nucleon-nucleon scattering data. The low-energy constant dˆR (cD), which cannot be determined from the purely two-nucleon data, was extracted recently from the triton β-decay and the binding energies of the three-nucleon systems. The calculated values of Λ1 / 2 show a rather large spread for the used values of the dˆR. Precise measurement of Λ1 / 2 in the future will not only help to constrain the value of dˆR, but also provide a highly nontrivial test of the nuclear chiral EFT framework. Besides, the precise knowledge of the constant dˆR will allow for consistent calculations of other two-nucleon weak processes, such as proton-proton fusion and solar neutrino scattering on deuterons, which are important for astrophysics.
Adam, J; Tater, M; Truhlik, E; Epelbaum, E; Machleidt, R; Ricci, P
2011-01-01
The doublet capture rate of the negative muon capture in deuterium is calculated employing the nuclear wave functions generated from accurate nucleon-nucleon potentials constructed at next-to-next-to-next-to-leading order of heavy-baryon chiral perturbation theory and the weak meson exchange current operator derived within the same formalism. All but one of the low-energy constants that enter the calculation were fixed from pion-nucleon and nucleon-nucleon scattering data. The low-energy constant d^R (c_D), which cannot be determined from the purely two-nucleon data, was extracted recently from the triton beta-decay and the binding energies of the three-nucleon systems. The calculated values of the doublet capture rates show a rather large spread for the used values of the d^R. Precise measurement of the doublet capture rate in the future will not only help to constrain the value of d^R, but also provide a highly nontrivial test of the nuclear chiral EFT framework. Besides, the precise knowledge of the consta...
Low-energy neutron-deuteron reactions with N{sup 3}LO chiral forces
Golak, J.; Skibinski, R.; Topolnicki, K.; Witala, H. [Jagiellonian University, M. Smoluchowski Institute of Physics, Krakow (Poland); Epelbaum, E.; Krebs, H. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Bochum (Germany); Kamada, H. [Kyushu Institute of Technology, Department of Physics, Faculty of Engineering, Kitakyushu (Japan); Meissner, Ulf G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); JARA - High Performance Computing Forschungszentrum Juelich, Institute for Advanced Simulation, Institut fuer Kernphysik, Juelich Center for Hadron Physics, Juelich (Germany); Bernard, V. [CNRS/Univ. Paris-Sud, Institut de Physique Nucleaire, Orsay (France); Maris, P.; Vary, J. [Iowa State University, Department of Physics and Astronomy, Ames, Iowa (United States); Binder, S.; Calci, A.; Langhammer, J.; Roth, R. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); Hebeler, K. [Technische Universitaet Darmstadt, Institut fuer Kernphysik, Darmstadt (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Extreme Matter Institute EMMI, Darmstadt (Germany); Nogga, A. [Juelich Center for Hadron Physics, Forschungszentrum Juelich, Institut fuer Kernphysik, Institute for Advanced Simulation, Juelich (Germany); Liebig, S.; Minossi, D. [Juelich Center for Hadron Physics, Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany)
2014-11-15
We solve three-nucleon Faddeev equations with nucleon-nucleon and three-nucleon forces derived consistently in the framework of chiral perturbation theory at next-to-next-to-next-to-leading order in the chiral expansion. In this first investigation we include only matrix elements of the three-nucleon force for partial waves with the total two-nucleon (three-nucleon) angular momenta up to 3 (5/2). Low-energy neutron-deuteron elastic scattering and deuteron breakup reaction are studied. Emphasis is put on A{sub y} puzzle in elastic scattering and cross sections in symmetric-space-star and neutron-neutron quasi-free-scattering breakup configurations, for which large discrepancies between data and theory have been reported. (orig.)
Low-energy neutron-deuteron reactions with N3LO chiral forces
Golak, J; Topolnicki, K; Witala, H; Epelbaum, E; Krebs, H; Kamada, H; Meissner, Ulf-G; Bernard, V; Maris, P; Vary, J; Binder, S; Calci, A; Hebeler, K; Langhammer, J; Roth, R; Nogga, A; Liebig, S; Minossi, D
2014-01-01
We solve three-nucleon Faddeev equations with nucleon-nucleon and three-nucleon forces derived consistently in the framework of chiral perturbation theory at next-to-next-to-next-to-leading order in the chiral expansion. In this first investigation we include only matrix elements of the three-nucleon force for partial waves with the total two-nucleon (three-nucleon) angular momenta up to 3 (5/2). Low-energy neutron-deuteron elastic scattering and deuteron breakup reaction are studied. Emphasis is put on Ay puzzle in elastic scattering and cross sections in symmetric-space-star and neutron-neutron quasi-free-scattering breakup configurations, for which large discrepancies between data and theory have been reported.
Fundamental nucleon-nucleon interaction: probing exotic nuclear structure using GEANIE at LANCE/WNR
Bernstein, L
2000-02-25
The initial goal of this project was to study the in-medium nucleon-nucleon interaction by testing the fundamental theory of nuclear structure, the shell model, for nuclei between {sup 8}Zr and {sup 100}Sn. The shell model predicts that nuclei with ''magic'' (2,8,20,28,40,50, and 82) numbers of protons or neutrons form closed shells in the same fashion as noble gas atoms [may49]. A ''doubly magic'' nucleus with a closed shell of both protons and neutrons has an extremely simple structure and is therefore ideal for studying the nucleon-nucleon interaction. The shell model predicts that doubly magic nuclei will be spherical and that they will have large first-excited-state energies ({approx} 1 to 3 MeV). Although the first four doubly-magic nuclei exhibit this behavior, the N = Z = 40 nucleus, {sup 80}Zr, has a very low first-excited-state energy (290 keV) and appears to be highly deformed. This breakdown is attributed to the small size of the shell gap at N = Z = 40. If this description is accurate, then the N = Z = 50 doubly magic nucleus, {sup 100}Sn, will exhibit ''normal'' closed-shell behavior. The unique insight provided by doubly-magic nuclei from {sup 80}Zr to {sup 100}Sn has made them the focus of tremendous interest in the nuclear structure community. However, doubly-magic nuclei heavier than {sup 56}Ni become increasingly difficult to form due to the coulomb repulsion between the protons which favors the formation of neutron-rich nuclei. The coulomb repulsion creates a ''proton drip-line'' beyond which the addition of any additional bound protons is energetically impossible. The drip line renders the traditional experimental technique used in their formation, the heavy-ion reaction, less than ideal as a method of forming doubly-magic nuclei beyond {sup 80}Zr. The result has been a lack of an new spectroscopic information on doubly magic nuclei in more than a decade [lis87
Liu Jian Ye; Wang, S J; Zuo, W; Zhao, Q; Yang Yong Feng; Liu, Jian-Ye; Guo, Wen-Jun; Wang, Shun-Jin; Zuo, Wei; Zhao, Qiang; Yang, Yan-Fang
2001-01-01
Using an isospin-dependent quantum molecular dynamics, nuclear stopping in intermediate heavy ion collisions has been studied. The calculation has been done for colliding systems with different neutron-proton ratios in beam energy ranging from 15MeV/u to 150MeV/u. It is found that, in the energy region from above Fermi energy to 150MeV/u, nuclear stopping is very sensitive to the isospin dependence of in-medium nucleon-nucleon cross section, but insensitive to symmetry potential. From this investigation, we propose that nuclear stopping can be used as a new probe to extract the information on the isospin dependence of in-medium nucleon-nucleon cross section in intermediate energy heavy ion collisions.
Fujiwara, Y; Kohno, M; Suzuki, Y
2004-01-01
Quark-model nucleon-nucleon and hyperon-nucleon interactions by the Kyoto- Niigata group are applied to the hypertriton calculation in a new three-cluster Faddeev formalism using the two-cluster resonating-group method kernels. The most recent model, fss2, gives a reasonable result similar to the Nijmegen soft-core model NSC89, except for an appreciable contributions of higher partial waves.
The one-pion-exchange potential in the three-body model of nucleon-nucleon scattering
Garcilazo, Humberto
1981-02-01
We derive the one-pion-exchange potential in the three-body model of nucleon-nucleon scattering in which the nucleon is treated as a bound state of a pion and a nucleon, and show that it has the same form as the usual Yukawa OPEP derived from field theory, except that its range is energy dependent and it becomes complex above the pion-production threshold.
A Realistic Description of Nucleon-Nucleon and Hyperon-Nucleon Interactions in the SU_6 Quark Model
Fujiwara, Y; Kohno, M; Nakamoto, C; Suzuki, Y
2001-01-01
We upgrade a SU_6 quark-model description for the nucleon-nucleon and hyperon-nucleon interactions by improving the effective meson-exchange potentials acting between quarks. For the scalar- and vector-meson exchanges, the momentum-dependent higher-order term is incorporated to reduce the attractive effect of the central interaction at higher energies. The single-particle potentials of the nucleon and Lambda, predicted by the G-matrix calculation, now have proper repulsive behavior in the momentum region q_1=5 - 20 fm^-1. A moderate contribution of the spin-orbit interaction from the scalar-meson exchange is also included. As to the vector mesons, a dominant contribution is the quadratic spin-orbit force generated from the rho-meson exchange. The nucleon-nucleon phase shifts at the non-relativistic energies up to T_lab=350 MeV are greatly improved especially for the 3E states. The low-energy observables of the nucleon-nucleon and the hyperon-nucleon interactions are also reexamined. The isospin symmetry break...
The isospin dependent nucleon-nucleon inelastic cross section in the nuclear medium
Li, Qingfeng; Li, Zhuxia
2017-10-01
The calculation of the energy-, density-, and isospin-dependent Δ production cross sections in nucleon-nucleon (NN) scattering σNN→ NΔ * has been performed within the framework of the relativistic BUU approach. The NΔ cross sections are calculated in Born approximation taking into account the effective mass splitting of the nucleons and Δs in asymmetric matter. Due to the different mass splitting for neutron, proton and differently charged Δs, it is shown that, similar to the NN elastic ones, the reductions of NΔ inelastic cross sections in isospin-asymmetric nuclear medium are different from each other for all the individual channels and the effect is largest and of opposite sign for the Δ++ and Δ- states. This approach is also compared to calculations without effective mass splitting and with splitting derived from Dirac-Brueckerner (DB) calculations. The isospin dependence of the NΔ cross sections is expected to influence the production of π+ and π- mesons as well as their yield ratio, and thus affect the use of the latter quantity as a probe of the stiffness of the symmetry energy at supranormal densities.
Nucleon-nucleon interactions in the double folding model for fusion reactions
Zhang Gao-Long; Liu Hao; Le Xiao-Yun
2009-01-01
Nucleus-nucleus potentials are determined in the framework of double folding model for M3Y-Reid and M3Y-Paris effective nucleon nucleon (NN) interactions. Both zero-range and finite-range exchange parts of NN interactions are considered in the folding procedure. In this paper the spherical projectile-spherical target system 16O+208Pb is selected for calculating the barrier energies, fusion cross sections and barrier distributions with the density-independent and density-dependcnt NN interactions on the basis of M3Y-Reid and M3Y-Paris NN interactions. The barrier energies become lower for Paris NN interactions in comparison with Reid NN interactions, and also for finite-range exchange part in comparison with zero-range exchange part. The density-dependent NN interactions give similar fusion cross sections and barrier distributions, and the density-independent NN interaction causes the barrier distribution moving to a higher position. However, the density-independent Reid NN interaction with zero-range exchange part gives the lowest fusion cross sections. We find that the calculated fusion cross sections and the barrier distributions are in agreement with the experimental data after rcnormalization of the nuclear potential due to coupled-channel effect.
The isospin dependent nucleon-nucleon inelastic cross section in the nuclear medium
Li, Qingfeng
2016-01-01
A theoretical calculation on the energy-, density-, and isospin-dependent nucleon-nucleon (NN) inelastic cross section $\\sigma^*_{NN\\rightarrow N\\Delta}$, based on the self-consistent relativistic Boltzmann-Uehling-Uhlenbeck microscopic transport theory, has been performed. It is found that the decrease of $\\sigma^*_{NN\\rightarrow N\\Delta}$ with the increase of density is relatively stronger than in previous isospin-averaged calculations by Mao {\\it et al.} [Phys. Lett. B {\\bf 327}, 183 (1994)], owing to a novel choice of the density-dependent parameter set for the equation of state. The reduction of the inelastic in-medium cross section is also compared with that of elastic and inelastic cross sections adopted in numerical model calculations, and it is found that the current calculation behaves reasonably well. Owing to the mass-splitting effect of both nucleons and $\\Delta$s, all individual channels are different from each other in the isospin-asymmetric nuclear medium, similar to the NN elastic cross secti...
Tensor-optimized shell model for the Li isotopes with a bare nucleon-nucleon interaction
Myo, Takayuki; Toki, Hiroshi; Ikeda, Kiyomi
2012-01-01
We study the Li isotopes systematically in terms of the tensor-optimized shell model (TOSM) by using a bare nucleon-nucleon interaction as the AV8' interaction. The short-range correlation is treated in the unitary correlation operator method (UCOM). Using the TOSM+UCOM approach, we investigate the role of the tensor force on each spectrum of the Li isotopes. It is found that the tensor force produces quite a characteristic effect on various states in each spectrum and those spectra are affected considerably by the tensor force. The energy difference between the spin-orbit partner, the p1/2 and p3/2 orbits of the last neutron, in 5Li is caused by opposite roles of the tensor correlation. In 6Li, the spin-triplet state in the LS coupling configuration is favored energetically by the tensor force in comparison with jj coupling shell model states. In 7,8,9Li, the low-lying states containing extra neutrons in the p3/2 orbit are favored energetically due to the large tensor contribution to allow the excitation fro...
Nucleon-Nucleon Scattering Parameters in the Limit of SU(3) Flavor Symmetry
Beane, S R; Cohen, S D; Detmold, W; Junnarkar, P; Lin, H W; Luu, T C; Orginos, K; Parreno, A; Savage, M J; Walker-Loud, A
2013-01-01
The scattering lengths and effective ranges that describe low-energy nucleon-nucleon scattering are calculated in the limit of SU(3)-flavor symmetry at the physical strange-quark mass with Lattice Quantum Chromodynamics. The calculations are performed with an isotropic clover discretization of the quark action in three volumes with spatial extents of L \\sim 3.4 fm, 4.5fm and 6.7 fm, and with a lattice spacing of b \\sim 0.145 fm. With determinations of the energies of the two-nucleon systems (both of which contain bound states at these up and down quark masses) at rest and moving in the lattice volume, Luscher's method is used to determine the low-energy phase shifts in each channel, from which the scattering length and effective range are obtained. The scattering parameters, in the 1S0 channel are found to be m_pi a^(1S0) = 9.50^{+0.78}_{-0.69}^{+1.10}_{-0.80} and m_pi r^(1S0) = {4.61^{+0.29}_{-0.31}^{+0.24}_{-0.26}, and in the 3S1 channel are m_pi a^(3S1) = 7.45^{+0.57}_{-0.53}^{+0.71}_{-0.49} and m_pi r^(3S...
Constraining in-medium nucleon-nucleon interactions via nucleus-nucleus reactions
Sammarruca, Francesca; White, Larz
2010-11-01
The nuclear equation of state is a broadly useful tool. Besides being the main input of stellar structure calculations, it allows a direct connection to the physics of nuclei. For instance, an energy functional (such as a mass formula), together with the energy/particle in nuclear matter, can be used to predict nuclear energies and radii [1]. The single-particle properties are also a key point to link infinite nuclear matter and actual nuclei. The parameters of the single-particle potential, in particular the effective mass, enter the calculations of, for instance, in-medium effective cross sections. From the well-known Glauber reaction theory, the total nucleus-nucleus reaction cross section is expressed in terms of the nuclear transparency, which, in turn, depends on the overlap of the nuclear density distributions and the elementary nucleon-nucleon (NN) cross sections. We explore the sensitivity of the reaction calculation to medium modifications of the NN cross sections to estimate the likelihood of constraining the latter through nuclear reactions. Ultimately, we wish to incorporate isospin asymmetry in the reaction model, having in mind connections with rare isotopes. [1] F. Sammarruca, arXiv:1002.00146 [nucl-th]; International Journal of Modern Physics, in press.
Uncertainty analysis and order-by-order optimization of chiral nuclear interactions
Carlsson, B D; Forssén, C; Strömberg, D Fahlin; Lilja, O; Lindby, M; Mattsson, B A; Wendt, K A
2015-01-01
Chiral effective field theory ($\\chi$EFT) provides a systematic approach to describe low-energy nuclear forces. Moreover, $\\chi$EFT is able to provide well-founded estimates of statistical and systematic uncertainties although this unique advantage has not yet been fully exploited. We fill this gap by performing an optimization and statistical analysis of all the low-energy constants (LECs) up to next-to-next-to-leading order. We simultaneously fit to scattering and bound-state observables in the pion-nucleon, nucleon-nucleon, and few-nucleon sectors in order to utilize the full model capabilities of $\\chi$EFT. Finally, we demonstrate methods to propagate uncertainties to other observables, such that they can easily be adopted by future works. We employ mathematical optimization and implement automatic differentiation to attain efficient and machine-precise first- and second-order derivatives of the objective function with respect to the LECs. This is also vital for the regression analysis. We use power-count...
Parity violation in few-nucleon systems within a chiral effective field theory framework
Viviani, Michele
2016-09-01
We study the effect the nucleon-nucleon parity violation (PV) interaction, induced by the weak interaction between quarks, in few-nucleon systems. First, we discuss the derivation of the nucleon-nucleon PV interaction within a chiral effective field theory framework, in particular its extension to next-to-next-to-leading order (N2LO), recently reported in. We report on an alternative derivation of this N2LO PV interaction using our technique based on the time-ordered perturbation theory, accounting also for cancellations between the contributions of irreducible diagrams and the contributions due to non-static corrections from energy denominators of reducible diagrams. Ultraviolet divergences associated with the loop corrections are isolated in dimensional regularization. A detailed analysis of the number of independent low-energy constants (LEC's) entering the potential is carried out. Then, we investigate PV effects induced by this updated potential on several few-nucleon observables, including the p-> - p longitudinal asymmetry, the neutron spin rotation in n-> - p and n-> - d scattering, and the longitudinal asymmetry in the 3He (n-> , p)3 H charge-exchange reaction.
Minimally non-local nucleon-nucleon potentials in $\\chi$EFT at order $Q^4$
Piarulli, M; Schiavilla, R; Pérez, R Navarro; Amaro, J E; Arriola, E Ruiz
2014-01-01
We construct a coordinate-space chiral potential, including $\\Delta$-isobar intermediate states in its two-pion-exchange component. The contact interactions entering at next-to-leading and next-to-next-to-next-to-leading orders ($Q^2$ and $Q^4$, respectively, $Q$ denoting generically the low momentum scale) are rearranged by Fierz transformations to yield terms at most quadratic in the relative momentum operator of the two nucleons. The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database, consisting of 2309 $pp$ and 2982 $np$ data (including, respectively, 148 and 218 normalizations) in the laboratory-energy range 0--300 MeV. For the total 5291 $pp$ and $np$ data in this range, we obtain a $\\chi^2$/datum of roughly 1.3 for a set of three models characterized by long- and short-range cutoffs, $R_{\\rm L}$ and $R_{\\rm S}$ respectively, ranging from $(R_{\\rm L},R_{\\rm S})=(1.2,0.8)$ fm down to $(0.8,0.6)$ fm. The long-range (short-range) cutoff regularizes the one- ...
Threshold pion production in proton-proton collisions at NNLO in chiral EFT
Baru, V.; Epelbaum, E.; Filin, A. A.; Hanhart, C.; Krebs, H.; Myhrer, F.
2016-05-01
The reaction NN → NN π offers a good testing ground for chiral effective field theory at intermediate energies. It challenges our understanding of the first inelastic channel in nucleon-nucleon scattering and of the charge symmetry breaking pattern in hadronic reactions. In our previous studies, we presented a complete calculation of the pion production operator for s -wave pions up-to-and-including next-to-next-to-leading order (NNLO) in the formulation of chiral effective field theory, which includes pions, nucleons and Δ(1232) degrees of freedom. In this paper we calculate the near-threshold cross section for the pp → d π+ reaction by performing the convolution of the obtained operators with nuclear wave functions based on modern phenomenological and chiral potentials. The available chiral NN wave functions are constructed with a cutoff comparable with the momentum transfer scale inherent in pion production reactions. Hence, a significant portion of the dynamical intermediate-range physics is thereby cut off by them. On the other hand, the NNLO amplitudes evaluated with phenomenological wave functions appear to be largely independent of the NN model used and give corrections to the dominant leading-order contributions as expected from dimensional analysis. The result gives support to the counting scheme used to classify the pion production operators, which is a precondition for a reliable investigation of the chirally suppressed neutral pion production. The explicit inclusion of the Δ(1232) is found to be important but smaller than expected due to cancellations.
Uncertainty Analysis and Order-by-Order Optimization of Chiral Nuclear Interactions
Carlsson, B. D.; Ekström, A.; Forssén, C.; Strömberg, D. Fahlin; Jansen, G. R.; Lilja, O.; Lindby, M.; Mattsson, B. A.; Wendt, K. A.
2016-01-01
Chiral effective field theory (χ EFT ) provides a systematic approach to describe low-energy nuclear forces. Moreover, χ EFT is able to provide well-founded estimates of statistical and systematic uncertainties—although this unique advantage has not yet been fully exploited. We fill this gap by performing an optimization and statistical analysis of all the low-energy constants (LECs) up to next-to-next-to-leading order. Our optimization protocol corresponds to a simultaneous fit to scattering and bound-state observables in the pion-nucleon, nucleon-nucleon, and few-nucleon sectors, thereby utilizing the full model capabilities of χ EFT . Finally, we study the effect on other observables by demonstrating forward-error-propagation methods that can easily be adopted by future works. We employ mathematical optimization and implement automatic differentiation to attain efficient and machine-precise first- and second-order derivatives of the objective function with respect to the LECs. This is also vital for the regression analysis. We use power-counting arguments to estimate the systematic uncertainty that is inherent to χ EFT , and we construct chiral interactions at different orders with quantified uncertainties. Statistical error propagation is compared with Monte Carlo sampling, showing that statistical errors are, in general, small compared to systematic ones. In conclusion, we find that a simultaneous fit to different sets of data is critical to (i) identify the optimal set of LECs, (ii) capture all relevant correlations, (iii) reduce the statistical uncertainty, and (iv) attain order-by-order convergence in χ EFT . Furthermore, certain systematic uncertainties in the few-nucleon sector are shown to get substantially magnified in the many-body sector, in particular when varying the cutoff in the chiral potentials. The methodology and results presented in this paper open a new frontier for uncertainty quantification in ab initio nuclear theory.
Hen, O; Piasetzky, E; Weinstein, L B
2016-01-01
This article reviews our current understanding of how the internal quark structure of a nucleon bound in nuclei differs from that of a free nucleon. We focus on the interpre- tation of measurements of the EMC effect for valence quarks, a reduction in the Deep Inelastic Scattering (DIS) cross-section ratios for nuclei relative to deuterium, and its possible connection to nucleon-nucleon Short-Range Correlations (SRC) in nuclei. Our review of the available experimental and theoretical evidence shows that there is a phe- nomenological relation between between the EMC effect and the effects of SRC that is not an accident. There is an underlying cause of both effects: the influence of strongly correlated neutron-proton pairs is largely responsible. This conclusion needs to be so- lidified by the future experiments and improved theoretical analyses that are discussed herein.
Fischer, Tobias
2016-01-01
In this article the neutrino-pair production from nucleon-nucleon (NN) bremsstrahlung is explored via medium-modifications of the strong interactions at the level of the one-pion exchange approximation. It governs the bulk part of the NN interaction at low densities relevant for the neutrino physics in core-collapse supernova studies. The resulting medium modified one-pion exchange rate for the neutrino-pair processes is implemented in simulations of core collapse supernovae in order to study the impact on the neutrino signal emitted from the deleptonization of the nascent proto-neutron star. Consequences for the nucleosynthesis of heavy elements of the material ejected from the PNS surface are discussed.
HUANG Hong-Xia; CHEN Ling-Zhi; PANG Hou-Rong; PING Jia-Lun; WANG Fan
2008-01-01
The symmetric spin-orbit/nteractions of one-gluon-exchange and confinement are included in the nucleon-nucleon phase shift calculation in the framework of quark delocalization colour screening model.The spin-orbit interaction has little influence on D wave phase shift.For the triplet P waves,3 pT is in good agreement with the experimental data and 3 pLS is attractive but not strong enough,whereas 3Pc is too strongly repulsive.Our results indicate that the symmetric spin-orbit interaction of one-gluon-exchange and confinement potential cannot give a good description of the triplet P wave phase shifts.More sophisticated considerations,the delocalization depending on the relative orientation between two duster,might be needed to improve the description of P-wave NN interaction.
Threshold pion production in proton-proton collisions at NNLO in chiral EFT
Baru, V; Filin, A A; Hanhart, C; Krebs, H; Myhrer, F
2016-01-01
The reaction $NN \\to NN \\pi$ offers a good testing ground for chiral effective field theory at intermediate energies. It challenges our understanding of the first inelastic channel in nucleon-nucleon scattering and of the charge-symmetry breaking pattern in hadronic reactions. In our previous studies, we presented a complete calculation of the pion-production operator for s-wave pions up-to-and-including next-to-next-to-leading order (NNLO) in the formulation of chiral effective field theory, which includes pions, nucleons and $\\Delta(1232)$ degrees of freedom. In this paper we calculate the near threshold cross section for the $pp \\to d \\pi^{+}$ reaction by performing the convolution of the obtained operators with nuclear wave functions based on modern phenomenological and chiral potentials. The available chiral $NN$ wave functions are constructed with a cutoff comparable with the momentum transfer scale inherent in pion production reactions. Hence, a significant portion of the dynamical intermediate-range p...
Zhi-Yong He [Caen Univ., 14 (France). Lab. de Physique Corpusculaire]|[Academia Sinica, Lanzhou, GS (China). Inst. of Modern Physics; Peter, J.; Angelique, J.C.; Bizard, G.; Brou, R.; Cussol, D. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Auger, A.; Cabot, C.; Crema, E. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Buta, A. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire]|[Institute of Atomic Physics, Bucharest (Romania)] [and others
1996-09-01
Experimental measurement and theoretical comparison of collective flow can give important information about the nuclear equation of state (EOS) and the in-medium nucleon-nucleon cross section. Experimental measurements of {sup 64}Zn+{sup 27}Al collision from 35 to 79 MeV/u with the 4{pi} array MUR=TONNEAU are presented. The results are compared to BUU calculations. (K.A.).
Nuclear matter saturation with chiral three-nucleon interactions fitted to light nuclei properties
Logoteta, Domenico; Bombaci, Ignazio; Kievsky, Alejandro
2016-07-01
The energy per particle of symmetric nuclear matter and pure neutron matter is calculated using the many-body Brueckner-Hartree-Fock approach and employing the Chiral Next-to-next-to-next-to leading order (N3LO) nucleon-nucleon (NN) potential, supplemented with various parametrizations of the Chiral Next-to-next-to leading order (N2LO) three-nucleon interaction. Such combination is able to reproduce several observables of the physics of light nuclei for suitable choices of the parameters entering in the three-nucleon interaction. We find that some of these parametrizations provide a satisfactory saturation point of symmetric nuclear matter and values of the symmetry energy and its slope parameter L in very good agreement with those extracted from various nuclear experimental data. Thus, our results represent a significant step toward a unified description of few- and many-body nuclear systems starting from two- and three-nucleon interactions based on the symmetries of QCD.
Epelbaum, E; Meißner, Ulf G
2000-01-01
We employ the chiral nucleon-nucleon potential derived in [Nucl. Phys. A 637 (1998) 107] to study bound and scattering states in the two-nucleon system. At next-to-leading order, this potential is the sum of renormalized one-pion and two-pion exchange and contact interactions. At next-to-next-to-leading order, we have additional chiral two-pion exchange with low-energy constants determined from pion-nucleon scattering. Alternatively, we consider the DELTA(1232) as an explicit degree of freedom in the effective field theory. The nine parameters related to the contact interactions can be determined by a fit to the np S- and P-waves and the mixing parameter epsilon sub 1 for laboratory energies below 100 MeV. The predicted phase shifts and mixing parameters for higher energies and higher angular momenta are mostly well described for energies below 300 MeV. The S-waves are described as precisely as in modern phenomenological potentials. We find a good description of the deuteron properties.
Threshold pion production in proton-proton collisions at NNLO in chiral EFT
Baru, V. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Bochum (Germany); Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Epelbaum, E.; Filin, A.A.; Krebs, H. [Ruhr-Universitaet Bochum, Institut fuer Theoretische Physik II, Bochum (Germany); Hanhart, C. [Forschungszentrum Juelich, Institut fuer Kernphysik, (Theorie) and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich (Germany); Myhrer, F. [University of South Carolina, Department of Physics and Astronomy, Columbia, SC (United States)
2016-05-15
The reaction NN→NNπ offers a good testing ground for chiral effective field theory at intermediate energies. It challenges our understanding of the first inelastic channel in nucleon-nucleon scattering and of the charge symmetry breaking pattern in hadronic reactions. In our previous studies, we presented a complete calculation of the pion production operator for s-wave pions up-to-and-including next-to-next-to-leading order (NNLO) in the formulation of chiral effective field theory, which includes pions, nucleons and Δ(1232) degrees of freedom. In this paper we calculate the near-threshold cross section for the pp → dπ{sup +} reaction by performing the convolution of the obtained operators with nuclear wave functions based on modern phenomenological and chiral potentials. The available chiral NN wave functions are constructed with a cutoff comparable with the momentum transfer scale inherent in pion production reactions. Hence, a significant portion of the dynamical intermediate-range physics is thereby cut off by them. On the other hand, the NNLO amplitudes evaluated with phenomenological wave functions appear to be largely independent of the NN model used and give corrections to the dominant leading-order contributions as expected from dimensional analysis. The result gives support to the counting scheme used to classify the pion production operators, which is a precondition for a reliable investigation of the chirally suppressed neutral pion production. The explicit inclusion of the Δ(1232) is found to be important but smaller than expected due to cancellations. (orig.)
Kaptari, L P
2004-01-01
Vector meson ($V = \\omega, \\phi$) production in near-threshold elementary nucleon-nucleon collisions $pp\\to ppV$, $pn\\to pnV$ and $pn\\to dV$ is studied within an effective meson-nucleon theory. It is shown that a set of effective parameters can be established to describe fairly well the available experimental data of angular distributions and the energy dependence of the total cross sections without explicit implementation of the Okubo-Zweig-Iisuka rule violation. Isospin effects are considered in detail and compared with experimental data whenever available.
Kuo, Thomas T. S; Holt, Jeremy W; Lee, Sabine
2010-01-01
This book provides a comprehensive overview of some key developments in the understanding of the nucleon-nucleon interaction and nuclear many-body theory. The main problems at the level of meson exchange physics have been solved, and we have an effective field theory using a phenomenological interaction pioneered by Achim Schwenk and Scott Bogner, which is nearly universally accepted as a unique low-momentum interaction that includes all experimental data to date. This understanding is based on a multi-step development in which different scientific insights and a wide range of physical and mat
Gontchar, I. I.; Chushnyakova, M. V.
2016-07-01
A systematic calculation of barriers for heavy-ion fusion was performed on the basis of the double-folding model by employing two versions of an effective nucleon-nucleon interaction: M3Y interaction and Migdal interaction. The results of calculations by the Hartree-Fockmethod with the SKX coefficients were taken for nuclear densities. The calculations reveal that the fusion barrier is higher in the case of employing theMigdal interaction than in the case of employing the M3Y interaction. In view of this, the use of the Migdal interaction in describing heavy-ion fusion is questionable.
Babenko, V A
2016-01-01
We study relationship between the physical quantities that characterize pion-nucleon and nucleon-nucleon interaction on the basis of the fact that nuclear forces in the nucleon-nucleon system at low energies are mainly determined by the one-pion exchange mechanism. By making use of the recommended proton-proton low-energy scattering parameters, we obtain the following value for the charged pion-nucleon coupling constant g$_{\\pi ^{\\pm }}^{2}/4\\pi =14.55(13)$. Calculated value of this quantity is in excellent agreement with the experimental result g$_{\\pi ^{\\pm }}^{2}/4\\pi =14.52(26)$ of the Uppsala Neutron Research Group. At the same time, the obtained value of the charged pion-nucleon coupling constant differs markedly from the value of the neutral pion-nucleon coupling constant g$_{\\pi ^{0}}^{2}/4\\pi =13.55(13)$. Thus, our results show considerable charge splitting of the pion-nucleon coupling constant.
Local chiral potentials with Δ-intermediate states and the structure of light nuclei
Piarulli, Maria
2017-01-01
We present a fully local nucleon-nucleon potential in chiral effective field theory (χEFT) retaining pions, nucleons and Δ-isobars as explicit degrees of freedom, and use it in hypersperical-harmonics and quantum Monte Carlo calculations of ground and excited states of 3H, 3He, 4He, 6He, and 6Li nuclei. The calculation of the potential is carried out by including one- and two-pion-exchange contributions up to next-to-next-to-leading order (N2LO) and contact interactions up to next-to-next-to-next-to-leading order (N3LO). The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database in two different ranges of laboratory energies, either 0-125 MeV or 0-200 MeV, and to the deuteron binding energy and nn singlet scattering length. Fits to these data are performed for three models characterized by long- and short-range cutoffs, RL and RS respectively, ranging from (RL ,RS) =(1 . 2 , 0 . 8) fm down to (0 . 8 , 0 . 6) fm. The long-range (short-range) cutoff regularizes the one- and two-pion exchange (contact) part of the potential.
Kievsky, A.; Viviani, M.; Gattobigio, M.; Girlanda, L.
2017-02-01
In chiral effective field theory the leading order (LO) nucleon-nucleon potential includes two contact terms, in the two spin channels S =0 ,1 , and the one-pion-exchange potential. When the pion degrees of freedom are integrated out, as in the pionless effective field theory, the LO potential includes two contact terms only. In the three-nucleon system, the pionless theory includes a three-nucleon contact term interaction at LO whereas the chiral effective theory does not. Accordingly arbitrary differences could be observed in the LO description of three- and four-nucleon binding energies. We analyze the two theories at LO and conclude that a three-nucleon contact term is necessary at this order in both theories. In turn this implies that subleading three-nucleon contact terms should be promoted to lower orders. Furthermore, this analysis shows that one single low-energy constant might be sufficient to explain the large values of the singlet and triplet scattering lengths.
Cao, X. G.; Cai, X. Z.; Ma, Y. G.; Fang, D. Q.; Zhang, G. Q.; Guo, W.; Chen, J. G.; Wang, J. S.
2012-10-01
Proton-neutron, neutron-neutron, and proton-proton momentum-correlation functions (Cpn,Cnn, and Cpp) are systematically investigated for 15C and other C-isotope-induced collisions at different entrance channel conditions within the framework of the isospin-dependent quantum-molecular-dynamics model complemented by the correlation after burner (crab) computation code. 15C is a prime exotic nucleus candidate due to the weakly bound valence neutron coupling with closed-neutron-shell nucleus 14C. To study density dependence of the correlation function by removing the isospin effect, the initialized 15C projectiles are sampled from two kinds of density distribution from the relativistic mean-field (RMF) model in which the valence neutron of 15C is populated in both 1d5/2 and 2s1/2 states, respectively. The results show that the density distributions of the valence neutron significantly influence the nucleon-nucleon momentum-correlation function at large impact parameters and high incident energies. The extended density distribution of the valence neutron largely weakens the strength of the correlation function. The size of the emission source is extracted by fitting the correlation function by using the Gaussian source method. The emission source size as well as the size of the final-state phase space are larger for projectile samplings from more extended density distributions of the valence neutron, which corresponds to the 2s1/2 state in the RMF model. Therefore, the nucleon-nucleon momentum-correlation function can be considered as a potentially valuable tool to diagnose exotic nuclear structures, such as the skin and halo.
Chiral potential renormalized in harmonic-oscillator space
Yang, C -J
2016-01-01
We renormalize the chiral effective field theory (EFT) potential in harmonic-oscillator (HO) model space. The low energy constants (LECs) are utilized to absorb not just the ultra-violet part of the physics due to the cutoff, but also the infrared part due to the truncation of model space. We use the inverse J-matrix method to reproduce the nucleon-nucleon (NN) scattering phase shifts in the given model space. We demonstrate that by including the NLO correction, the nucleon-nucleon scattering in the continuum could be well reproduced in the truncated HO trap space up to laboratory energy $T_{lab}=100$ MeV with number of HO basis $n_{max}$ as small as 10. A perturbative power counting starts at subleading order is adopted in this work, and how to extract the perturbative contribution is demonstrated. Our work serves as the input to perform ab-initio calculations.
Kievsky, A; Gattobigio, M; Girlanda, L
2016-01-01
In chiral effective field theory the leading order (LO) nucleon-nucleon potential includes two contact terms, in the two spin channels $S=0,1$, and the one-pion-exchange potential. When the pion degrees of freedom are integrated out, as in the pionless effective field theory, the LO potential includes two contact terms only. In the three-nucleon system, the pionless theory includes a three-nucleon contact term interaction at LO whereas the pionful theory does not. Accordingly arbitrary differences could be observed in the LO description of three- and four-nucleon binding energies. We analyze the two theories at LO and conclude that a three-nucleon contact term is necessary at this order in both theories. In turn this implies that subleading three-nucleon contact terms should be promoted to lower orders. Furthermore this analysis shows that one single low energy constant might be sufficient to explain the large values of the singlet and triplet scattering lengths.
A chiral effective field theory study of hadronic parity violation in few-nucleon systems
Viviani, M; Girlanda, L; Kievsky, A; Marcucci, L E; Schiavilla, R
2014-01-01
We reconsider the derivation of the nucleon-nucleon parity-violating (PV) potential within a chiral effective field theory framework. We construct the potential up to next-to-next-to-leading order by including one-pion-exchange, two-pion-exchange, contact, and 1/M (M being the nucleon mass) terms, and use dimensional regularization to renormalize the pion-loop corrections. A detailed analysis of the number of independent low-energy constants (LEC's) entering the potential is carried out. We find that it depends on six LEC's: the pion-nucleon PV coupling constant $h^1_\\pi$ and five parameters multiplying contact interactions. We investigate PV effects induced by this potential on several few-nucleon observables, including the $\\vec{p}$-$p$ longitudinal asymmetry, the neutron spin rotation in $\\vec{n}$-$p$ and $\\vec{n}$-$d$ scattering, and the longitudinal asymmetry in the $^3$He$(\\vec{n},p)^3$H charge-exchange reaction. An estimate for the range of values of the various LEC's is provided by using available exp...
Uncertainty quantification for proton-proton fusion in chiral effective field theory
Acharya, B.; Carlsson, B. D.; Ekström, A.; Forssén, C.; Platter, L.
2016-09-01
We compute the S-factor of the proton-proton (pp) fusion reaction using chiral effective field theory (χEFT) up to next-to-next-to-leading order (NNLO) and perform a rigorous uncertainty analysis of the results. We quantify the uncertainties due to (i) the computational method used to compute the pp cross section in momentum space, (ii) the statistical uncertainties in the low-energy coupling constants of χEFT, (iii) the systematic uncertainty due to the χEFT cutoff, and (iv) systematic variations in the database used to calibrate the nucleon-nucleon interaction. We also examine the robustness of the polynomial extrapolation procedure, which is commonly used to extract the threshold S-factor and its energy-derivatives. By performing a statistical analysis of the polynomial fit of the energy-dependent S-factor at several different energy intervals, we eliminate a systematic uncertainty that can arise from the choice of the fit interval in our calculations. In addition, we explore the statistical correlations between the S-factor and few-nucleon observables such as the binding energies and point-proton radii of 2,3H and 3He as well as the D-state probability and quadrupole moment of 2H, and the β-decay of 3H. We find that, with the state-of-the-art optimization of the nuclear Hamiltonian, the statistical uncertainty in the threshold S-factor cannot be reduced beyond 0.7%.
Uncertainty quantification for proton-proton fusion in chiral effective field theory
Acharya, B; Ekström, A; Forssén, C; Platter, L
2016-01-01
We compute the $S$-factor of the proton-proton ($pp$) fusion reaction using chiral effective field theory ($\\chi$EFT) up to next-to-next-to-leading order (NNLO) and perform a rigorous uncertainty analysis of the results. We quantify the uncertainties due to (i) the computational method used to compute the $pp$ cross section in momentum space, (ii) the statistical uncertainties in the low-energy coupling constants of $\\chi$EFT, (iii) the systematic uncertainty due to the $\\chi$EFT cutoff, and (iv) systematic variations in the database used to calibrate the nucleon-nucleon interaction. We also examine the robustness of the polynomial extrapolation procedure, which is commonly used to extract the threshold $S$-factor and its energy-derivatives. By performing a statistical analysis of the polynomial fit of the energy-dependent $S$-factor at several different energy intervals, we eliminate a systematic uncertainty that can arise from the choice of the fit interval in our calculations. In addition, we explore the s...
Korover, I.; Muangma, N.; Hen, O.; Shneor, R.; Sulkosky, V.; Kelleher, A.; Gilad, S.; Higinbotham, D. W.; Piasetzky, E.; Watson, J. W.; Wood, S. A.; Aguilera, P.; Ahmed, Z.; Albataineh, H.; Allada, K.; Anderson, B.; Anez, D.; Aniol, K.; Annand, J.; Armstrong, W.; Arrington, J.; Averett, T.; Badman, T.; Baghdasaryan, H.; Bai, X.; Beck, A.; Beck, S.; Bellini, V.; Benmokhtar, F.; Bertozzi, W.; Bittner, J.; Boeglin, W.; Camsonne, A.; Chen, C.; Chen, J.-P.; Chirapatpimol, K.; Cisbani, E.; Dalton, M. M.; Daniel, A.; Day, D.; de Jager, C. W.; De Leo, R.; Deconinck, W.; Defurne, M.; Flay, D.; Fomin, N.; Friend, M.; Frullani, S.; Fuchey, E.; Garibaldi, F.; Gaskell, D.; Gilman, R.; Glamazdin, O.; Gu, C.; Gueye, P.; Hamilton, D.; Hanretty, C.; Hansen, J.-O.; Hashemi Shabestari, M.; Holmstrom, T.; Huang, M.; Iqbal, S.; Jin, G.; Kalantarians, N.; Kang, H.; Khandaker, M.; LeRose, J.; Leckey, J.; Lindgren, R.; Long, E.; Mammei, J.; Margaziotis, D. J.; Markowitz, P.; Marti Jimenez-Arguello, A.; Meekins, D.; Meziani, Z.; Michaels, R.; Mihovilovic, M.; Monaghan, P.; Munoz Camacho, C.; Norum, B.; Nuruzzaman, Pan, K.; Phillips, S.; Pomerantz, I.; Posik, M.; Punjabi, V.; Qian, X.; Qiang, Y.; Qiu, X.; Rakhman, A.; Reimer, P. E.; Riordan, S.; Ron, G.; Rondon-Aramayo, O.; Saha, A.; Schulte, E.; Selvy, L.; Shahinyan, A.; Sirca, S.; Sjoegren, J.; Slifer, K.; Solvignon, P.; Sparveris, N.; Subedi, R.; Tireman, W.; Wang, D.; Weinstein, L. B.; Wojtsekhowski, B.; Yan, W.; Yaron, I.; Ye, Z.; Zhan, X.; Zhang, J.; Zhang, Y.; Zhao, B.; Zhao, Z.; Zheng, X.; Zhu, P.; Zielinski, R.; Jefferson Lab Hall A Collaboration
2014-07-01
We studied simultaneously the He4(e ,e'p), He4(e ,e'pp), and He4(e ,e'pn) reactions at Q2=2(GeV/c)2 and xB>1, for an (e ,e'p) missing-momentum range of 400 to 830 MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A =2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum, in a region where the nucleon-nucleon (NN) force is expected to change from predominantly tensor to repulsive. The abundance of neutron-proton pairs is reduced as the nucleon momentum increases beyond ˜500 MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum. Our data are compared with calculations of two-nucleon momentum distributions in He4 and discussed in the context of probing the elusive repulsive component of the NN force.
Chatrchyan, Serguei [Yerevan Physics Inst. (Armenia); et al.
2011-08-01
Jet production in PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV was studied with the CMS detector at the LHC, using a data sample corresponding to an integrated luminosity of 6.7 inverse microbarns. Jets are reconstructed using the energy deposited in the CMS calorimeters and studied as a function of collision centrality. With increasing collision centrality, a striking imbalance in dijet transverse momentum is observed, consistent with jet quenching. The observed effect extends from the lower cut-off used in this study (jet transverse momentum = 120 GeV/c) up to the statistical limit of the available data sample (jet transverse momentum approximately 210 GeV/c). Correlations of charged particle tracks with jets indicate that the momentum imbalance is accompanied by a softening of the fragmentation pattern of the second most energetic, away-side jet. The dijet momentum balance is recovered when integrating low transverse momentum particles distributed over a wide angular range relative to the direction of the away-side jet.
Liu Jian-Ye; Guo Wen-Jun; Xing Yong-Zhong
2007-01-01
Probing in-medium nucleon-nucleon (NN) cross section σ(1N)N(α) in heavy ion collisions has been investigated by means of the isospin-depeadent quantum molecular dynamics (IQMD) with the isospin-and momentum-dependent interaction (IMDI(τ)). It is found that there are the very obvious medium effect and the sensitive isospin-dependence of nuclear stopping R on the in-medium NN cross section σ(1N)N(α) in the nuclear reactions induced by halo-neutron projectile and the same-mass stable projectile. However, R induced by the neutron-halo projectile is obviously lower than that induced by the corresponding stable projectile. In particular, there is a very obvious dependence of R on the medium effect of σ(1N)N(α) in the whole beam energy region for the above two kinds of projectiles. Therefore, the comparison between the results of R's in the reactions induced by the neutron-halo projectile and the corresponding same-mass stable projectile is a more favourable probe for extracting the information of σ(1N)N(α) because of adding a new judgement.
Li, Cheng; Qin, Yujiao; Li, Jingjing; Wang, Ning
2013-01-01
The nucleon-nucleon interaction is investigated by using the ImQMD model with the three sets of parameters IQ1, IQ2 and IQ3 in which the corresponding incompressibility coefficients of nuclear matter are different. The charge distribution of fragments for various reaction systems are calculated at different incident energies. The parameters strongly affect the charge distribution below the threshold energy of nuclear multifragmentation. The fragment multiplicity spectrum for $^{238}$U+$^{197}$Au at 15 AMeV and the charge distribution for $^{129}$Xe+$^{120}$Sn at 32 and 45 AMeV, and $^{197}$Au+$^{197}$Au at 35 AMeV are reproduced by the ImQMD model with the set of parameter IQ3. It is concluded that charge distribution of the fragments and the fragment multiplicity spectrum are good observables for studying N-N interaction, the Fermi energy region is a sensitive energy region to explore the N-N interaction, and IQ3 is a suitable set of parameters for the ImQMD model.
Wang, Yongjia; Guo, Chenchen; Li, Qingfeng; Li, Zhuxia; Su, Jun; Zhang, Hongfei
2016-08-01
We considered three different nucleon-nucleon (NN) elastic differential cross sections: the Cugnon et al. parameterized differential cross section [Nucl. Instrum. Methods Phys. Res., Sect. B 111, 215 (1996), 10.1016/0168-583X(95)01384-9], the differential cross section derived from the collision term of the self-consistent relativistic Boltzmann-Uehling-Uhlenbeck equation proposed by Mao et al. [Z. Phys. A 347, 173 (1994), 10.1007/BF01292373], and the isotropic differential cross section within the newly updated version of the ultrarelativistic quantum molecular dynamics (UrQMD) model. By doing so, we investigated the influence of the differential elastic NN cross section on various observables (e.g., nuclear stopping, both the rapidity and transverse-velocity dependence of the directed and elliptic flows) in Au+Au collisions at beam energies 150, 250, 400, and 800 MeV /nucleon . By comparing calculations with those three differential cross sections, we found that the nuclear stopping power and the directed and elliptic flows are affected to some extent by the differential cross sections, and the impact of differential cross section on those observables becomes more visible as the beam energy increases. The effect on the elliptic flow difference v2n-v2H and ratio v2n/v2H of neutrons versus hydrogen isotopes (Z =1 ), which have been used as sensitive observables for probing nuclear symmetry energy at high densities, is weak.
Muangma, I Korover N; Shneor, R; Sulkosky, V; Kelleher, A; Gilad, S; Higinbotham, D W; Watson, E Piasetzky J; Wood, S; Rakhman, Abdurahim; Aguilera, P; Ahmed, Z; Albataineh, H; Allada, K; Anderson, B; Anez, D; Aniol, K; Annand, J; Armstrong, W; Arrington, J; Averett, T; Badman, T; Baghdasaryan, H; Bai, X; Beck, A; Beck, S; Bellini, V; Benmokhtar, F; Bertozzi, W; Bittner, J; Boeglin, W; Camsonne, A; Chen, C; Chen, J -P; Chirapatpimol, K; Cisbani, E; Dalton, M; Daniel, A; Day, D; de Jager, C W; De Leo, R; Deconinck, W; Defurne, M; Flay, D; Fomin, N; Friend, M; Frullani, S; Fuchey, E; Garibaldi, F; Gaskell, D; Gilman, R; Glamazdin, O; Gu, C; Gueye, P; Hamilton, D; Hanretty, C; Hansen, O; Shabestari, M Hashemi; Holmstrom, T; Huang, M; Iqbal, S; Jin, G; Kalantarians, N; Kang, H; Khandaker, M; LeRose, J; Leckey, J; Lindgren, R; Long, E; Mammei, J; Margaziotis, D J; Markowitz, P; Jimenez-Arguello, A Marti; Meekins, D; Meziani, Z; Michaels, R; Mihovilovic, M; Monaghan, P; Camacho, C Munoz; Norum, B; Nuruzzaman,; Pan, K; Phillips, S; Pomerantz, I; Posik, M; Punjabi, V; Qian, X; Qiang, Y; Qiu, X; Reimer, P E; Riordan, S; Ron, G; Rondon-Aramayo, O; Saha, A; Schulte, E; Selvy, L; Shahinyan, A; Sirca, S; Sjoegren, J; Slifer, K; Solvignon, P; Sparveris, N; Subedi, R; Tireman, W; Wang, D; Weinstein, L B; Wojtsekhowski, B; Yan, W; Yaron, I; Ye, Z; Zhan, X; Zhang, J; Zhang, Y; Zhao, B; Zhao, Z; Zheng, X; Zhu, P; Zielinski, R
2014-01-01
We measured simultaneously the 4He(eep), 4He(eepp), and 4He(e,e'pn) reactions at Q^2=2 [GeV/c]2 and x_B>1, for a (e,e'p) missing-momentum range of 400 to 830 MeV/c. The knocked-out proton was detected in coincidence with a proton or neutron recoiling almost back to back to the missing momentum, leaving the residual A=2 system at low excitation energy. These data were used to identify two-nucleon short-range correlated pairs and to deduce their isospin structure as a function of missing momentum in a region where the nucleon-nucleon force is expected to change from predominantly tensor to repulsive. Neutron-proton pairs dominate the high-momentum tail of the nucleon momentum distributions, but their abundance is reduced as the nucleon momentum increases beyond ~500 MeV/c. The extracted fraction of proton-proton pairs is small and almost independent of the missing momentum in the range we studied. Our data are compared with ab-initio calculations of two-nucleon momentum distributions in 4He.
Wang, Yongjia; Li, Qingfeng; Li, Zhuxia; Su, Jun; Zhang, Hongfei
2016-01-01
By considering three different Nucleon-Nucleon (NN) elastic differential cross sections: the Cugnon \\emph{et al.} parameterized differential cross section [Nucl. Instrum. Methods Phys. Res., Sect. \\textbf{B111}, 215 (1996)], and the differential cross section derived from the collision term of the self-consistent relativistic Boltzmann-Uehling-Uhlenbeck equation proposed by Mao \\emph{et al.} [Z.\\ Phys.\\ A {\\bf 347}, 173 (1994)], as well as the isotropic differential cross section, within the newly updated version of the ultrarelativistic quantum molecular dynamics (UrQMD) model, the influence of the differential elastic NN cross section on various observables (e.g., nuclear stopping, both the rapidity and transverse-velocity dependence of the directed and elliptic flows) in Au+Au collisions at beam energies 150, 250, 400, and 800 MeV$/$nucleon is investigated. By comparing calculations with those three differential cross sections, it is found that the nuclear stopping power, the directed and elliptic flows ar...
Cao, X G; Ma, Y G; Fang, D Q; Zhang, G Q; Guo, W; Chen, J G; Wang, J S; 10.1103/PhysRevC.86.044620
2012-01-01
Proton-neutron, neutron-neutron and proton-proton momentum correlation functions ($C_{pn}$, $C_{nn}$, $C_{pp}$) are systematically investigated for $^{15}$C and other C isotopes induced collisions at different entrance channel conditions within the framework of the isospin-dependent quantum molecular dynamics (IDQMD) model complemented by the CRAB (correlation after burner) computation code. $^{15}$C is a prime exotic nucleus candidate due to the weakly bound valence neutron coupling with closed-neutron shell nucleus $^{14}$C. In order to study density dependence of correlation function by removing the isospin effect, the initialized $^{15}$C projectiles are sampled from two kinds of density distribution from RMF model, in which the valence neutron of $^{15}$C is populated on both 1$d$5/2 and 2$s$1/2 states, respectively. The results show that the density distributions of valence neutron significantly influence nucleon-nucleon momentum correlation function at large impact parameter and high incident energy. T...
Khoa, D T
2004-01-01
Fully quantal calculations of the total reaction cross sections \\sigR and interaction cross sections \\sigI, induced by stable and unstable He, Li, C and O isotopes on $^{12}$C target at $E_{\\rm lab}\\approx 0.8$ and 1 GeV/nucleon have been performed, for the first time, in the distorted wave impulse approximation (DWIA) using the microscopic \\emph{complex} optical potential and inelastic form factors given by the folding model. Realistic nuclear densities for the projectiles and $^{12}$C target as well as the complex $t$-matrix parameterization of free nucleon-nucleon interaction by Franey and Love were used as inputs of the folding calculation. Our \\emph{parameter-free} folding + DWIA approach has been shown to give a very good account (within 1--2%) of the experimental \\sigI measured at these energies for the stable, strongly bound isotopes. With the antisymmetrization of the dinuclear system properly taken into account, this microscopic approach is shown to be more accurate than the simple optical limit of ...
Testing Lorentz Symmetry using Chiral Perturbation Theory
Noordmans, J P
2016-01-01
We consider the low-energy effects of a selected set of Lorentz- and CPT-violating quark and gluon operators by deriving the corresponding chiral effective lagrangian. Using this effective lagrangian, low-energy hadronic observables can be calculated. We apply this to magnetometer experiments and derive the best bounds on some of the Lorentz-violating coefficients. We point out that progress can be made by studying the nucleon-nucleon potential, and by considering storage-ring experiments for deuterons and other light nuclei.
Delfino, A; Frederico, T
1996-01-01
The link between non-linear chiral effective Lagrangians and the Walecka model description of bulk nuclear matter [1] is questioned. This fact is by itself due to the Mean Field Approximation (MFA) which in nuclear mater makes the picture of a nucleon-nucleon interaction based on scalar(vector) meson exchange, equivalent to the description of a nuclear matter based on attractive and repulsive contact interactions. We present a linear chiral model where this link between the Walecka model and an underlying to chiral symmetry realization still holds, due to MFA.
Modern Chiral Forces Applied to the Nucleon-Deuteron Radiative Capture
Skibiński, Roman; Golak, Jacek; Topolnicki, Kacper; Witała, Henryk; Epelbaum, Evgeny; Kamada, Hiroyuki; Krebs, Hermann; Meißner, Ulf-G.; Nogga, Andreas
2017-03-01
The chiral nucleon-nucleon interaction with semi-local regularization up to the fifth order of chiral expansion is applied to the nucleon-deuteron radiative capture process. Our theoretical approach is based on the formalism of Faddeev equations and the Siegert theorem is exploited to construct the electromagnetic current operator. The very weak dependence of the differential cross section on values of the regularization parameter is observed. This suggests that the improved chiral two-body interaction is a promising starting point to study electromagnetic processes at low energies.
Gluonic Lorentz violation and chiral perturbation theory
Noordmans, J. P.
2017-04-01
By applying chiral-perturbation-theory methods to the QCD sector of the Lorentz-violating Standard-Model Extension, we investigate Lorentz violation in the strong interactions. In particular, we consider the C P T -even pure-gluon operator of the minimal Standard-Model Extension. We construct the lowest-order chiral effective Lagrangian for three as well as two light quark flavors. We develop the power-counting rules and construct the heavy-baryon chiral-perturbation-theory Lagrangian, which we use to calculate Lorentz-violating contributions to the nucleon self-energy. Using the constructed effective operators, we derive the first stringent limits on many of the components of the relevant Lorentz-violating parameter. We also obtain the Lorentz-violating nucleon-nucleon potential. We suggest that this potential may be used to obtain new limits from atomic-clock or deuteron storage-ring experiments.
Su, Jun; Huang, Ching-Yuan [Sun Yat-sen University, Sino-French Institute of Nuclear Engineering and Technology, Zhuhai (China); Xie, Wen-Jie [Yuncheng University, Department of Physics, Yuncheng (China); Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); Zhang, Feng-Shou [Beijing Normal University, The Key Laboratory of Beam Technology and Material Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing (China); Beijing Radiation Center, Beijing (China); National Laboratory of Heavy Ion Accelerator of Lanzhou, Center of Theoretical Nuclear Physics, Lanzhou (China)
2016-07-15
The effects of in-medium nucleon-nucleon cross sections on the stopping observable and ratio of free protons in heavy-ion collisions at 400 MeV/nucleon have been investigated within the framework of the IQMD+GEMINI model. Five kinds of in-medium corrections of nucleon-nucleon cross sections, which are considerably different in the referred energy and density, have been used in the model. It has been found that calculations of the stopping decrease when the in-medium cross sections decrease. Moreover, the ratio of free protons R{sub p} depends not only on the value of the in-medium factors but also on its isospin dependence. In order to investigate the isospin effect of in-medium factors on the ratio of free protons R{sub p}, the isospin dependence of in-medium factors has been adjusted and used in the model. The calculations have shown that the isospin dependence of in-medium factors does not impact the stopping, but impacts the ratio of free protons R{sub p}. When the in-medium factors relation f{sub nn}{sup med} > f{sub pp}{sup med} is used in the model, the calculated values of R{sub p} are larger than those in the f{sub nn}{sup med} < f{sub pp}{sup med} case. (orig.)
Symmetric Wilson Loops beyond leading order
Chen-Lin, Xinyi
2016-01-01
We study the circular Wilson loop in the symmetric representation of U(N) in $\\mathcal{N} = 4$ super-Yang-Mills (SYM). In the large N limit, we computed the exponentially-suppressed corrections for strong coupling, which suggests non-perturbative physics in the dual holographic theory. We also computed the next-to-leading order term in 1/N, and the result matches with the exact result from the k-fundamental representation.
Leading order QCD in Coulomb gauge
Watson, Peter
2011-01-01
Coulomb gauge QCD in the first order formalism can be written in terms of a ghost-free, nonlocal action that ensures total color charge conservation via Gauss' law. Making an Ansatz whereby the nonlocal term (the Coulomb kernel) is replaced by its expectation value, the resulting Dyson-Schwinger equations can be derived. With a leading order truncation, these equations reduce to the gap equations for the static gluon and quark propagators obtained from a quasi-particle approximation to the canonical Hamiltonian approach. Moreover a connection to the heavy quark limit can be established, allowing an intuitive explanation for the charge constraint and infrared divergences.
Finite nuclei in relativistic models with a light chiral scalar meson
Furnstahl, R. J.; Serot, Brian D.
1993-05-01
Relativistic chiral models with a light scalar meson appear to provide an economical marriage of successful relativistic mean-field theories and chiral symmetry. The scalar meson serves as both the chiral partner of the pion and the mediator of the intermediate-range nucleon-nucleon (NN) attraction. However, while some of these models can reproduce the empirical nuclear matter saturation point, they fail to reproduce observed properties of finite nuclei, such as spin-orbit splittings, shell structure, charge densities, and surface energetics. These deficiencies imply that this realization of chiral symmetry is incorrect. An alternative scenario, which features a heavy chiral scalar and dynamical generation of the NN attraction, is discussed.
Strangeness $S=-1$ hyperon-nucleon scattering at leading order in the covariant Weinberg's approach
Li, Kai-Wen; Geng, Li-Sheng
2016-01-01
Inspired by the success of covariant baryon chiral perturbation theory in the one baryon sector and in the heavy-light systems, we explore the relevance of relativistic effects in the construction of the strangeness $S=-1$ hyperon-nucleon interaction using chiral perturbation theory. Due to the non-perturbative nature of the hyperon-nucleon interaction, we follow the covariant Weinberg's approach recently proposed by Epelbaum and Gegelia to sum the leading order chiral potential using the Kadyshevsky equation (Epelbaum, 2012) in this exploratory work. By fitting the five low-energy constants to available experimental data, we find that the cutoff dependence is mitigated compared with the results obtained in the Weinberg's approach for both partial wave phase shifts and the description of experimental data. Nevertheless, at leading order, the description of experimental data remains quantitatively similar. We discuss in detail the cutoff dependence of the partial wave phase shifts and cross sections in the Wei...
NN-πNN equations and the chiral bag model
Afnan, I. R.; Blankleider, B.
1985-12-01
The NN-πNN equations that describe, in a unified framework, pion production in nucleon-nucleon scattering, and pion-deuteron and nucleon-nucleon elastic scattering, have been extended to include the N(939) and Δ(1232) on an equal footing. This extension, motivated by the quark models of hadrons, has the bare N and Δ as three quark states with the same spacial wave function, but different spin isospin states. The final equations, referred to as the BB-πBB equations, are consistent with the chiral bag models to the extent that the πNN, πNΔ, and πΔΔ coupling constants and form factors are related, and can be taken from bag models. The resultant equations satisfy two- and three-body unitarity, and are derived by exposing the lowest unitarity cuts in the n-body Green's function. These equations retain important contributions missing from the NN-πNN equations. For pion production and N-N scattering they include the contribution of backward pions in the NN-->NΔ transition potential, which may overcome the problem of small pp-->πd cross section as predicted by the NN-πNN equations. For π-d elastic scattering they include an additional NΔ-->NΔ tensor force that can influence the tensor polarization.
NN-. pi. NN equations and the chiral bag model
Afnan, I.R.; Blankleider, B.
1985-12-01
The NN-..pi..NN equations that describe, in a unified framework, pion production in nucleon-nucleon scattering, and pion-deuteron and nucleon-nucleon elastic scattering, have been extended to include the N(939) and ..delta..(1232) on an equal footing. This extension, motivated by the quark models of hadrons, has the bare N and ..delta.. as three quark states with the same spacial wave function, but different spin isospin states. The final equations, referred to as the BB-..pi..BB equations, are consistent with the chiral bag models to the extent that the ..pi..NN, ..pi..N..delta.., and ..pi delta delta.. coupling constants and form factors are related, and can be taken from bag models. The resultant equations satisfy two- and three-body unitarity, and are derived by exposing the lowest unitarity cuts in the n-body Green's function. These equations retain important contributions missing from the NN-..pi..NN equations. For pion production and N-N scattering they include the contribution of backward pions in the NN..-->..N..delta.. transition potential, which may overcome the problem of small pp..--> pi..d cross section as predicted by the NN-..pi..NN equations. For ..pi..-d elastic scattering they include an additional N..delta -->..N..delta.. tensor force that can influence the tensor polarization.
Bulla, A.
1990-05-31
The traditional formulation of nuclear physics with purely nucleonic degrees of freedom is only in the low-energy region acceptable; already in the intermediate-energy range, in which in scattering experiments inelastic processes as the production of pions occur, a conceptual extension is inevitably neccessary. In front of this background a force model is constructed, in which beside the nucleons additionally the {Delta} isobar as well as the pions occur as constituents. The support of the formulated approach form static interactions between the baryons respectively between the baryons and the pion. Essential characteristic of this approach is the inclusion of pion production and absorption processes in form of pion-baryon vertices. Self-interactions lead in the {Delta} isobar to an energy dependent mass and decay widths. The {pi}NN system allows a manifold of reactions, of which here the nucleon-nucleon scattering below and above the pion production threshold is treated. Scattering phases, inelasticities (and mixing parameters in the phase of coupled NN partial waves) as well as spin-averaged and spin dependent total cross sections are calculated and compared with experimental data. (orig./HSI).
Chatrchyan, Serguei [Yerevan Physics Inst. (Armenia); et al.
2011-07-01
First measurements of dihadron correlations for charged particles are presented for central PbPb collisions at a nucleon-nucleon center-of-mass energy of 2.76 TeV over a broad range in relative pseudorapidity, Delta(eta), and the full range of relative azimuthal angle, Delta(phi). The data were collected with the CMS detector, at the LHC. A broadening of the away-side (Delta(phi) approximately pi) azimuthal correlation is observed at all Delta(eta), as compared to the measurements in pp collisions. Furthermore, long-range dihadron correlations in Delta(eta) are observed for particles with similar phi values. This phenomenon, also known as the "ridge", persists up to at least |Delta(eta)| = 4. For particles with transverse momenta (pt) of 2-4 GeV/c, the ridge is found to be most prominent when these particles are correlated with particles of pt = 2-6 GeV/c, and to be much reduced when paired with particles of pt = 10-12 GeV/c.
Gadioli, E; Catarisano, C; Cavinato, M; Connell, S H; Cowley, A A; Fabrici, E; Förtsch, S V; Gadioli-Erba, E; Lawrie, J J; Sellschop, J P Friedel; Sideras-Haddad, E; Steyn, G F
2002-01-01
Two different reaction mechanisms (which both occur at very short interaction times) contribute to the emission of intermediate mass fragments in reactions induced by a light nucleus such as sup 1 sup 6 O. They are the binary fragmentation of the projectile and the coalescence of nucleons during the course of the nucleon-nucleon interaction cascade which starts as soon as the two ions (or part of them) come into contact. These two mechanisms are easily distinguished from each other because their contributions to measured emission spectra have different energy dependence, the first peaking at an energy not far from that corresponding to the beam velocity, the other to a much smaller energy about equal to the Coulomb barrier between the observed fragment and an heavy residue with mass and charge near to those of the target nucleus. These features are clearly observed in the spectra of carbon fragments produced in the interaction of sup 1 sup 6 O ions with sup 5 sup 9 Co and sup 9 sup 3 Nb at incident energies b...
Pion-nucleon scattering: from chiral perturbation theory to Roy-Steiner equations
Kubis, Bastian; Hoferichter, Martin; de Elvira, Jacobo Ruiz; Meißner, Ulf-G.
2016-11-01
Ever since Weinberg's seminal predictions of the pion-nucleon scattering amplitudes at threshold, this process has been of central interest for the study of chiral dynamics involving nucleons. The scattering lengths or the pion-nucleon σ-term are fundamental quantities characterizing the explicit breaking of chiral symmetry by means of the light quark masses. On the other hand, pion-nucleon dynamics also strongly affects the long-range part of nucleon-nucleon potentials, and hence has a far-reaching impact on nuclear physics. We discuss the fruitful combination of dispersion-theoretical methods, in the form of Roy-Steiner equations, with chiral dynamics to determine pion-nucleon scattering amplitudes at low energies with high precision.*
The Matrix Element Method at Next-to-Leading Order
Campbell, John M.; Giele, Walter T.; Williams, Ciaran
2012-01-01
This paper presents an extension of the matrix element method to next-to-leading order in perturbation theory. To accomplish this we have developed a method to calculate next-to-leading order weights on an event-by-event basis. This allows for the definition of next-to-leading order likelihoods in exactly the same fashion as at leading order, thus extending the matrix element method to next-to-leading order. A welcome by-product of the method is the straightforward and efficient generation of...
The matrix element method at next-to-leading order
Campbell, John M.; Giele, Walter T.; Williams, Ciaran
2012-11-01
This paper presents an extension of the matrix element method to next-to-leading order in perturbation theory, for electro-weak final states. To accomplish this we have developed a method to calculate next-to-leading order weights on an event-by-event basis. This allows for the definition of next-to-leading order likelihoods in exactly the same fashion as at leading order, thus extending the matrix element method to next-to-leading order. A welcome by-product of the method is the straightforward and efficient generation of unweighted next-to-leading order events. As examples of the application of our next-to-leading order matrix element method we consider the measurement of the mass of the Z boson and also the search for the Higgs boson in the four lepton channel.
Accurate nuclear radii and binding energies from a chiral interaction
Ekstrom, A; Wendt, K A; Hagen, G; Papenbrock, T; Carlsson, B D; Forssen, C; Hjorth-Jensen, M; Navratil, P; Nazarewicz, W
2015-01-01
The accurate reproduction of nuclear radii and binding energies is a long-standing challenge in nuclear theory. To address this problem two-nucleon and three-nucleon forces from chiral effective field theory are optimized simultaneously to low-energy nucleon-nucleon scattering data, as well as binding energies and radii of few-nucleon systems and selected isotopes of carbon and oxygen. Coupled-cluster calculations based on this interaction, named NNLOsat, yield accurate binding energies and radii of nuclei up to 40Ca, and are consistent with the empirical saturation point of symmetric nuclear matter. In addition, the low-lying collective 3- states in 16O and 40Ca are described accurately, while spectra for selected p- and sd-shell nuclei are in reasonable agreement with experiment.
Selected two- and three-body electroweak processes with improved chiral forces
Skibinski, R; Topolnicki, K; Witala, H; Epelbaum, E; Kamada, H; Krebs, H; Meissner, Ulf-G; Nogga, A
2016-01-01
The recently developed semi-local improved chiral nucleon-nucleon interaction is used for the first time to study several electromagnetic and weak processes at energies below the pion production threshold. Cross sections and selected polarization observables for deuteron photodisintegration, nucleon-deuteron radiative capture, three-body 3He photodisintegration as well as capture rates for decays of the muonic 2H and 3He atoms are calculated. The Lippmann-Schwinger and Faddeev equations in momentum space are solved to obtain nuclear states. The electromagnetic current operator is taken as a single nucleon current supplemented by many-body contributions induced via the Siegert theorem. For muon capture processes the nonrelativistic weak current together with the dominant relativistic corrections is used. Our results compare well with experimental data, demonstrating the same quality as is observed for the semi-phenomenological AV18 potential. Compared to the older version of the chiral potential with a nonloca...
Nucleon-nucleon scattering at medium energies
Afnan, I. R.
1984-03-01
A model of the N-N potential, at medium energies, in the frame work of the BB-πBB equations, is presented. The derivation is based on the Cloudy Bag Model Hamiltonian. Recent N-N calculations are reviewed in the frame work of the model. Theoretical methods for the analysis of dibaryon resonances are compared.
Nucleon-nucleon scattering at medium energies
Afnan, I.R. (Flinders Univ. of South Australia, Bedford Park. School of Physical Sciences)
1984-03-26
A model of the N-N potential, at medium energies, in the framework of the BB-..pi..BB equations, is presented. The derivation is based on the Cloudy Bag Model Hamiltonian. Recent N-N calculations are reviewed in the framework of the model. Theoretical methods for the analysis of dibaryon resonances are compared. 30 refs.
Pion production in nucleon-nucleon scattering
Afnan, I.R.
1982-01-01
A model describing pion production in proton-proton interactions is presented. The model includes both single nucleon and two nucleon mechanisms. A system of equations representing the reaction is derived and results calculated using these equations are presented.
Strangeness s = -3 dibaryons in a chiral quark model
Lian-Rong, D; Chun-Ran, L; Lei, T; Lian-Rong, Dai; Dan, Zhang; Chun-Ran, Li; Lei, Tong
2006-01-01
The structures of $N\\Omega_{(2,1/2)}$ and $\\Delta\\Omega_{(3,3/2)}$ with strangeness $s=-3$ are dynamically studied in both the chiral SU(3) quark model and the extended chiral SU(3) quark model by solving a resonating group method (RGM) equation. The first model parameters are taken from our previous work, which gave a satisfactory description of the energies of the baryon ground states, the binding energy of the deuteron, the nucleon-nucleon(NN) scattering phase shifts, and the hyperon-nucleon (YN) cross sections. The effect from the vector meson fields is very similar to that from the one-gluon exchange interaction, both in the chiral SU(3) quark model and the extended chiral SU(3) quark model, the $N\\Omega_{(2,1/2)}$ and $\\Delta\\Omega_{(3,3/2)}$ systems are wealy bound states. The second model parameters are also taken from our previous work by fitting the KN scattering process. when the mixing of scalar mesons are considered, the $N\\Omega_{(2,1/2)}$ and $\\Delta\\Omega_{(3,3/2)}$ systems change into unbound...
Hadronic Parity Violation at Next-to-Leading Order
Tiburzi, B C
2012-01-01
The flavor-conserving non-leptonic weak interaction can be studied experimentally through the observation of parity violation in nuclear and few-body systems. At hadronic scales, matrix elements of parity-violating four-quark operators ultimately give rise to the parity violating couplings between hadrons, and such matrix elements can be calculated non-perturbatively using lattice QCD. In this work, we investigate the running of isovector parity-violating operators from the weak scale down to hadronic scales using the renormalization group. We work at next-to-leading order in the QCD coupling, and include both neutral-current and charged-current interactions. At this order, results are renormalization scheme dependent, and we utilize 't Hooft-Veltman dimensional regularization. The evolution of Wilson coefficients at leading and next-to-leading order is compared. Next-to-leading order effects are shown to be non-negligible at hadronic scales.
Hadronic parity violation at next-to-leading order
Tiburzi, B. C.
2012-03-01
The flavor-conserving nonleptonic weak interaction can be studied experimentally through the observation of parity violation in nuclear and few-body systems. At hadronic scales, matrix elements of parity-violating four-quark operators ultimately give rise to the parity-violating couplings between hadrons, and such matrix elements can be calculated nonperturbatively using lattice QCD. In this work, we investigate the running of isovector parity-violating operators from the weak scale down to hadronic scales using the renormalization group. We work at next-to-leading order in the QCD coupling, and include both neutral-current and charged-current interactions. At this order, results are renormalization-scheme dependent, and we utilize ’t Hooft-Veltman dimensional regularization. The evolution of Wilson coefficients at leading and next-to-leading order is compared. Next-to-leading-order effects are shown to be non-negligible at hadronic scales.
Shining LUX on isospin-violating dark matter beyond leading order
Vincenzo Cirigliano
2014-12-01
Full Text Available Isospin-violating dark matter (IVDM has been proposed as a viable scenario to reconcile conflicting positive and null results from direct detection dark matter experiments. We show that the lowest-order dark matter-nucleus scattering rate can receive large and nucleus-dependent corrections at next-to-leading order (NLO in the chiral expansion. The size of these corrections depends on the specific couplings of dark matter to quark flavors and gluons. In general the full NLO dark-matter-nucleus cross-section is not adequately described by just the zero-energy proton and neutron couplings. These statements are concretely illustrated in a scenario where the dark matter couples to quarks through scalar operators. We find the canonical IVDM scenario can reconcile the null XENON and LUX results and the recent CDMS-Si findings provided its couplings to second and third generation quarks either lie on a special line or are suppressed. Equally good fits with new values of the neutron-to-proton coupling ratio are found in the presence of nonzero heavy quark couplings. We also derive the structure of the scattering amplitude to all orders in the chiral expansion and show the best fit points at NLO are robust against higher order corrections provided the chiral expansion is itself well-behaved. CDMS-Si remains in tension with LUX and XENON10/100 but is not excluded.
Next-to-leading order corrections to the valon model
G R Bouroun; E Esfandyari
2016-01-01
A seminumerical solution to the valon model at next-to-leading order (NLO) in the Laguerre polynomials is presented. We used the valon model to generate the structure of proton with respect to the Laguerre polynomials method. The results are compared with H1 data and other parametrizations.
Higgs production at next-to-next-to-leading order
V Ravindran; J Smith; W L Van Neerven
2004-03-01
We describe the calculation of inclusive Higgs boson production at hadronic colliders at next-to-next-to-leading order (NNLO) in perturbative quantum chromodynamics. We have used the technique developed in ref. [4]. Our results agree with those published earlier in the literature.
Collinear limits beyond the leading order from the scattering equations
Nandan, Dhritiman; Wormsbecher, Wadim
2016-01-01
The structure of tree-level scattering amplitudes for collinear massless bosons is studied beyond their leading splitting function behavior. These near-collinear limits at sub-leading order are best studied using the Cachazo-He-Yuan (CHY) formulation of the S-matrix based on the scattering equations. We compute the collinear limits for gluons, gravitons and scalars. It is shown that the CHY integrand for an n-particle gluon scattering amplitude in the collinear limit at sub-leading order is expressed as a convolution of an (n-1)-particle gluon integrand and a collinear kernel integrand, which is universal. Our representation is shown to obey recently proposed amplitude relations in which the collinear gluons of same helicity are replaced by a single graviton. Finally, we extend our analysis to effective field theories and study the collinear limit of the non-linear sigma model, Einstein-Maxwell-Scalar and Yang-Mills-Scalar theory.
Collinear limits beyond the leading order from the scattering equations
Nandan, Dhritiman; Plefka, Jan; Wormsbecher, Wadim
2017-02-01
The structure of tree-level scattering amplitudes for collinear massless bosons is studied beyond their leading splitting function behavior. These near-collinear limits at sub-leading order are best studied using the Cachazo-He-Yuan (CHY) formulation of the S-matrix based on the scattering equations. We compute the collinear limits for gluons, gravitons and scalars. It is shown that the CHY integrand for an n-particle gluon scattering amplitude in the collinear limit at sub-leading order is expressed as a convolution of an ( n - 1)-particle gluon integrand and a collinear kernel integrand, which is universal. Our representation is shown to obey recently proposed amplitude relations in which the collinear gluons of same helicity are replaced by a single graviton. Finally, we extend our analysis to effective field theories and study the collinear limit of the non-linear sigma model, Einstein-Maxwell-Scalar and Yang-Mills-Scalar theory.
Shining LUX on isospin-violating dark matter beyond leading order
Cirigliano, V.; Graesser, M. L.; Ovanesyan, G.
2014-01-01
Isospin-violating dark matter (IVDM) has been proposed as a viable scenario to reconcile conflicting positive and null results from direct detection dark matter experiments. We show that the lowest-order dark matter-nucleus scattering rate can receive large and nucleus-dependent corrections at next......-to-leading order (NLO) in the chiral expansion. The size of these corrections depends on the specific couplings of dark matter to quark flavors and gluons. In general the full NLO dark-matter-nucleus cross-section is not adequately described by just the zero-energy proton and neutron couplings. These statements...... are concretely illustrated in a scenario where the dark matter couples to quarks through scalar operators. We find the canonical IVDM scenario can reconcile the null XENON and LUX results and the recent CDMS-Si findings provided its couplings to second and third generation quarks either lie on a special line...
Ising and Gross-Neveu model in next-to-leading order
Knorr, Benjamin
2016-01-01
We study scalar and chiral fermionic models in next-to-leading order with the help of the functional renormalisation group. Their critical behaviour is of special interest in condensed matter systems, in particular graphene. To derive the beta functions, we make extensive use of computer algebra. The resulting flow equations were solved with pseudo-spectral methods to guarantee high accuracy. New estimates on critical quantities for both the Ising and the Gross-Neveu model are provided. For the Ising model, the estimates agree with earlier renormalisation group studies of the same level of approximation. By contrast, the approximation for the Gross-Neveu model retains many more operators than all earlier studies. For two Dirac fermions, the results agree with both lattice and large-$N_f$ calculations, but for a single flavour, different methods disagree quantitatively, and further studies are necessary.
The epsilon expansion at next-to-next-to-leading order with small imaginary chemical potential
Lehner, Christoph; Wettig, Tilo
2010-01-01
We discuss chiral perturbation theory for two and three quark flavors in the epsilon expansion at next-to-next-to-leading order (NNLO) including a small imaginary chemical potential. We calculate finite-volume corrections to the low-energy constants $\\Sigma$ and $F$ and determine the non-universal modifications of the theory, i.e., modifications that cannot be mapped to random matrix theory (RMT). In the special case of two quark flavors in an asymmetric box we discuss how to minimize the finite-volume corrections and non-universal modifications by an optimal choice of the lattice geometry. Furthermore we provide a detailed calculation of a special version of the massless sunset diagram at finite volume.
Quenched Chiral Perturbation Theory to one loop
Colangelo, G.; Pallante, E.
1998-01-01
The divergences of the generating functional of quenched Chiral Perturbation theory (qCHPT) to one loop are computed in closed form. We show how the quenched chiral logarithms can be reabsorbed in the renormalization of the B0 parameter of the leading order Lagrangian. Finally, we do the chiral powe
Next-to-leading order corrections in exclusive meson production
Diehl, M.; Kugler, W.
2007-08-15
We analyze in detail the size of next-to-leading order corrections to hard exclusive meson production within the collinear factorization approach. Corrections to the cross section are found to be huge at small x{sub B} and substantial in typical fixed-target kinematics. With the models we take for nucleon helicity-flip distributions, the transverse target polarization asymmetry in vector meson production is strongly affected by radiative corrections, except at large x{sub B}. Its overall size is very small for {rho} production but can be large in the {omega} channel. (orig.)
The Agent of extracting Internet Information with Lead Order
Mo, Zan; Huang, Chuliang; Liu, Aijun
In order to carry out e-commerce better, advanced technologies to access business information are in need urgently. An agent is described to deal with the problems of extracting internet information that caused by the non-standard and skimble-scamble structure of Chinese websites. The agent designed includes three modules which respond to the process of extracting information separately. A method of HTTP tree and a kind of Lead algorithm is proposed to generate a lead order, with which the required web can be retrieved easily. How to transform the extracted information structuralized with natural language is also discussed.
Longitudinal Conductivity in Strong Magnetic Field in Perturbative QCD: Complete Leading Order
Hattori, Koichi; Satow, Daisuke; Yee, Ho-Ung
2016-01-01
We compute the longitudinal electrical conductivity in the presence of strong background magnetic field in complete leading order of perturbative QCD, based on the assumed hierarchy of scales $\\alpha_s eB\\ll (m_q^2,T^2)\\ll eB$. We formulate an effective kinetic theory of lowest Landau level quarks with the leading order QCD collision term arising from 1-to-2 processes that become possible due to 1+1 dimensional Landau level kinematics. In small $m_q/T\\ll 1$ regime, the longitudinal conductivity behaves as $\\sigma_{zz}\\sim e^2(eB)T/(\\alpha_s m_q^2\\log(m_q/T))$, where the quark mass dependence can be understood from the chiral anomaly with the axial charge relaxation provided by a finite quark mass $m_q$. We also present parametric estimates for the longitudinal and transverse "color conductivities" in the presence of strong magnetic field, by computing dominant damping rates for quarks and gluons that are responsible for color charge transportation. We observe that the longitudinal color conductivity is enhanc...
Driving Missing Data at Next-to-Leading Order
Bern, Z; Dixon, L J; Cordero, F Febres; Hoeche, S; Ita, H; Kosower, D A; Maitre, D; Ozeren, K J
2011-01-01
The prediction of backgrounds to new physics signals in topologies with large missing transverse energy and jets is important to new physics searches at the LHC. Following a CMS study, we investigate theoretical issues in using measurements of gamma + 2-jet production to predict the irreducible background to searches for missing energy plus two jets that originates from Z + 2-jet production where the Z boson decays to neutrinos. We compute ratios of gamma + 2-jet to Z + 2-jet production cross sections and kinematic distributions at next-to-leading order in alpha_s, as well as using a parton shower matched to leading-order matrix elements. We find that the ratios obtained in the two approximations are quite similar, making gamma + 2-jet production a theoretically reliable estimator for the missing energy plus two jets background. We employ a Frixione-style photon isolation, but we also show that for isolated prompt photon production at high transverse momentum the difference between this criterion and the stan...
Classical equation of motion and anomalous dimensions at leading order
Nii, Keita
2016-07-01
Motivated by a recent paper by Rychkov-Tan [1], we calculate the anomalous dimensions of the composite operators at the leading order in various models including a ϕ 3-theory in (6 - ɛ) dimensions. The method presented here relies only on the classical equation of motion and the conformal symmetry. In case that only the leading expressions of the critical exponents are of interest, it is sufficient to reduce the multiplet recombination discussed in [1] to the classical equation of motion. We claim that in many cases the use of the classical equations of motion and the CFT constraint on two- and three-point functions completely determine the leading behavior of the anomalous dimensions at the Wilson-Fisher fixed point without any input of the Feynman diagrammatic calculation. The method developed here is closely related to the one presented in [1] but based on a more perturbative point of view.
The a-function in three dimensions: beyond leading order
Jack, I
2016-01-01
Recently, evidence was provided for the existence of an $a$-function for renormalisable quantum field theories in three dimensions. An explicit expression was given at lowest order for general theories involving scalars and fermions, and shown to be related to the beta-functions by a gradient flow equation with positive-definite metric as in four dimensions. Here, we extend this lowest-order calculation to a general abelian Chern-Simons gauge theory coupled to fermions and scalars, and derive a prediction for part of the four-loop Yukawa beta-function. We also compute the complete four-loop Yukawa beta-function for the scalar-fermion theory and show that it is entirely consistent with the gradient flow equations at next-to-leading order.
Barik, N; Mohanty, D K; Panda, P K; Frederico, T
2013-01-01
We have calculated the properties of nuclear matter in a self-consistent manner with quark-meson coupling mechanism incorporating structure of nucleons in vacuum through a relativistic potential model; where the dominant confining interaction for the free independent quarks inside a nucleon, is represented by a phenomenologically average potential in equally mixed scalar-vector harmonic form. Corrections due to spurious centre of mass motion as well as those due to other residual interactions such as the one gluon exchange at short distances and quark-pion coupling arising out of chiral symmetry restoration; have been considered in a perturbation manner to obtain the nucleon mass in vacuum. The nucleon-nucleon interaction in nuclear matter is then realized by introducing additional quark couplings to sigma and omega mesons through mean field approximations. The relevant parameters of the interaction are obtained self consistently while realizing the saturation properties such as the binding energy, pressure a...
Classical equation of motion and Anomalous dimensions at leading order
Nii, Keita
2016-01-01
Motivated by a recent paper by Rychkov-Tan \\cite{Rychkov:2015naa}, we calculate the anomalous dimensions of the composite operators at the leading order in various models including a $\\phi^3$-theory in $(6-\\epsilon)$ dimensions. The method presented here relies only on the classical equation of motion and the conformal symmetry. In case that only the leading expressions of the critical exponents are of interest, it is sufficient to reduce the multiplet recombination discussed in \\cite{Rychkov:2015naa} to the classical equation of motion. We claim that in many cases the use of the classical equations of motion and the CFT constraint on two- and three-point functions completely determine the leading behavior of the anomalous dimensions at the Wilson-Fisher fixed point without any input of the Feynman diagrammatic calculation. The method developed here is closely related to the one presented in \\cite{Rychkov:2015naa} but based on a more perturbative point of view.
Revisiting the vector form factor at next-to-leading order in 1/N{sub C}
Rosell, Ignasi, E-mail: rosell@uch.ceu.e [Departamento de Ciencias Fisicas, Matematicas y de la Computacion, Universidad CEU Cardenal Herrera, c/ Sant Bartomeu 55, E-46115 Alfara del Patriarca, Valencia (Spain); IFIC, Universitat de Valencia - CSIC, Apt. Correus 22085, E-46071 Valencia (Spain)
2010-10-15
Using the Resonance Chiral Theory lagrangian, we perform a calculation of the vector form factor of the pion at the next-to-leading order (NLO) in the 1/N{sub C} expansion. Imposing the correct QCD short-distance constraints, one determines it in terms of F, G{sub V}, F{sub A} and resonance masses. Its low momentum expansion fixes then the low-energy chiral couplings L{sub 9} and C{sub 88} -C{sub 90} at NLO, keeping full control of their renormalization scale dependence. At {mu}{sub 0} = 0.77 GeV, we obtain L{sup r}{sub 9}({mu}{sub 0}) = (7.6 {+-} 0.6) . 10{sup -3} and C{sup r}{sub 88}({mu}{sub 0}) -C{sup r}{sub 90}({mu}{sub 0}) = (-4.5 {+-} 0.5) . 10{sup -5}.
Khachatryan, Vardan; et al.
2016-10-02
Charge-dependent azimuthal particle correlations with respect to the second-order event plane in pPb and PbPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV have been studied with the CMS experiment at the LHC. The measurement is performed with a three-particle correlation technique, using two particles with the same or opposite charge within the pseudorapidity range abs(eta)<2.4, and a third particle measured in the hadron forward calorimeters (4.4< abs(eta)<5). The observed differences between the same and opposite sign correlations, as functions of multiplicity and eta gap between the two charged particles, are of similar magnitude in pPb and PbPb collisions at the same multiplicities. These results pose a challenge for the interpretation of charge-dependent azimuthal correlations in heavy ion collisions in terms of the chiral magnetic effect.
Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; König, A.; Krätschmer, I.; Liko, D.; Matsushita, T.; Mikulec, I.; Rabady, D.; Rad, N.; Rahbaran, B.; Rohringer, H.; Schieck, J.; Strauss, J.; Waltenberger, W.; Wulz, C.-E.; Dvornikov, O.; Makarenko, V.; Zykunov, V.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; De Wolf, E. A.; Janssen, X.; Lauwers, J.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Abu Zeid, S.; Blekman, F.; D'Hondt, J.; Daci, N.; De Bruyn, I.; Deroover, K.; Lowette, S.; Moortgat, S.; Moreels, L.; Olbrechts, A.; Python, Q.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Parijs, I.; Brun, H.; Clerbaux, B.; De Lentdecker, G.; Delannoy, H.; Fasanella, G.; Favart, L.; Goldouzian, R.; Grebenyuk, A.; Karapostoli, G.; Lenzi, T.; Léonard, A.; Luetic, J.; Maerschalk, T.; Marinov, A.; Randle-conde, A.; Seva, T.; Vander Velde, C.; Vanlaer, P.; Vannerom, D.; Yonamine, R.; Zenoni, F.; Zhang, F.; Cimmino, A.; Cornelis, T.; Dobur, D.; Fagot, A.; Garcia, G.; Gul, M.; Khvastunov, I.; Poyraz, D.; Salva, S.; Schöfbeck, R.; Sharma, A.; Tytgat, M.; Van Driessche, W.; Yazgan, E.; Zaganidis, N.; Bakhshiansohi, H.; Beluffi, C.; Bondu, O.; Brochet, S.; Bruno, G.; Caudron, A.; De Visscher, S.; Delaere, C.; Delcourt, M.; Francois, B.; Giammanco, A.; Jafari, A.; Jez, P.; Komm, M.; Krintiras, G.; Lemaitre, V.; Magitteri, A.; Mertens, A.; Musich, M.; Nuttens, C.; Piotrzkowski, K.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Wertz, S.; Beliy, N.; Aldá Júnior, W. L.; Alves, F. L.; Alves, G. A.; Brito, L.; Hensel, C.; Moraes, A.; Pol, M. E.; Rebello Teles, P.; Belchior Batista Das Chagas, E.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; Da Silveira, G. G.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Huertas Guativa, L. M.; Malbouisson, H.; Matos Figueiredo, D.; Mora Herrera, C.; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Ahuja, S.; Bernardes, C. A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Moon, C. S.; Novaes, S. F.; Padula, Sandra S.; Romero Abad, D.; Ruiz Vargas, J. C.; Aleksandrov, A.; Hadjiiska, R.; Iaydjiev, P.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Fang, W.; Ahmad, M.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Chen, Y.; Cheng, T.; Jiang, C. H.; Leggat, D.; Liu, Z.; Romeo, F.; Shaheen, S. M.; Spiezia, A.; Tao, J.; Wang, C.; Wang, Z.; Zhang, H.; Zhao, J.; Ban, Y.; Chen, G.; Li, Q.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; González Hernández, C. F.; Ruiz Alvarez, J. D.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Puljak, I.; Ribeiro Cipriano, P. M.; Sculac, T.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Ferencek, D.; Kadija, K.; Mesic, B.; Micanovic, S.; Sudic, L.; Susa, T.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Tsiakkouri, D.; Finger, M.; Finger, M.; Carrera Jarrin, E.; Abdelalim, A. A.; Mohammed, Y.; Salama, E.; Kadastik, M.; Perrini, L.; Raidal, M.; Tiko, A.; Veelken, C.; Eerola, P.; Pekkanen, J.; Voutilainen, M.; Härkönen, J.; Järvinen, T.; Karimäki, V.; Kinnunen, R.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Ghosh, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Kucher, I.; Locci, E.; Machet, M.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Zghiche, A.; Abdulsalam, A.; Antropov, I.; Baffioni, S.; Beaudette, F.; Busson, P.; Cadamuro, L.; Chapon, E.; Charlot, C.; Davignon, O.; Granier de Cassagnac, R.; Jo, M.; Lisniak, S.; Miné, P.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Pigard, P.; Regnard, S.; Salerno, R.; Sirois, Y.; Strebler, T.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Buttignol, M.; Chabert, E. C.; Chanon, N.; Collard, C.; Conte, E.; Coubez, X.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Le Bihan, A.-C.; Skovpen, K.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Bernet, C.; Boudoul, G.; Bouvier, E.; Carrillo Montoya, C. A.; Chierici, R.; Contardo, D.; Courbon, B.; Depasse, P.; El Mamouni, H.; Fan, J.; Fay, J.; Gascon, S.; Gouzevitch, M.; Grenier, G.; Ille, B.; Lagarde, F.; Laktineh, I. B.; Lethuillier, M.; Mirabito, L.; Pequegnot, A. L.; Perries, S.; Popov, A.; Sabes, D.; Sordini, V.; Vander Donckt, M.; Verdier, P.; Viret, S.; Toriashvili, T.; Tsamalaidze, Z.; Autermann, C.; Beranek, S.; Feld, L.; Heister, A.; Kiesel, M. K.; Klein, K.; Lipinski, M.; Ostapchuk, A.; Preuten, M.; Raupach, F.; Schael, S.; Schomakers, C.; Schulz, J.; Verlage, T.; Weber, H.; Zhukov, V.; Albert, A.; Brodski, M.; Dietz-Laursonn, E.; Duchardt, D.; Endres, M.; Erdmann, M.; Erdweg, S.; Esch, T.; Fischer, R.; Güth, A.; Hamer, M.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Knutzen, S.; Merschmeyer, M.; Meyer, A.; Millet, P.; Mukherjee, S.; Olschewski, M.; Padeken, K.; Pook, T.; Radziej, M.; Reithler, H.; Rieger, M.; Scheuch, F.; Sonnenschein, L.; Teyssier, D.; Thüer, S.; Cherepanov, V.; Flügge, G.; Kargoll, B.; Kress, T.; Künsken, A.; Lingemann, J.; Müller, T.; Nehrkorn, A.; Nowack, A.; Pistone, C.; Pooth, O.; Stahl, A.; Aldaya Martin, M.; Arndt, T.; Asawatangtrakuldee, C.; Beernaert, K.; Behnke, O.; Behrens, U.; Bin Anuar, A. A.; Borras, K.; Campbell, A.; Connor, P.; Contreras-Campana, C.; Costanza, F.; Diez Pardos, C.; Dolinska, G.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Eren, E.; Gallo, E.; Garay Garcia, J.; Geiser, A.; Gizhko, A.; Grados Luyando, J. M.; Gunnellini, P.; Harb, A.; Hauk, J.; Hempel, M.; Jung, H.; Kalogeropoulos, A.; Karacheban, O.; Kasemann, M.; Keaveney, J.; Kleinwort, C.; Korol, I.; Krücker, D.; Lange, W.; Lelek, A.; Leonard, J.; Lipka, K.; Lobanov, A.; Lohmann, W.; Mankel, R.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mittag, G.; Mnich, J.; Mussgiller, A.; Ntomari, E.; Pitzl, D.; Placakyte, R.; Raspereza, A.; Roland, B.; Sahin, M. Ö.; Saxena, P.; Schoerner-Sadenius, T.; Seitz, C.; Spannagel, S.; Stefaniuk, N.; Van Onsem, G. P.; Walsh, R.; Wissing, C.; Blobel, V.; Centis Vignali, M.; Draeger, A. R.; Dreyer, T.; Garutti, E.; Gonzalez, D.; Haller, J.; Hoffmann, M.; Junkes, A.; Klanner, R.; Kogler, R.; Kovalchuk, N.; Lapsien, T.; Lenz, T.; Marchesini, I.; Marconi, D.; Meyer, M.; Niedziela, M.; Nowatschin, D.; Pantaleo, F.; Peiffer, T.; Perieanu, A.; Poehlsen, J.; Sander, C.; Scharf, C.; Schleper, P.; Schmidt, A.; Schumann, S.; Schwandt, J.; Stadie, H.; Steinbrück, G.; Stober, F. M.; Stöver, M.; Tholen, H.; Troendle, D.; Usai, E.; Vanelderen, L.; Vanhoefer, A.; Vormwald, B.; Akbiyik, M.; Barth, C.; Baur, S.; Baus, C.; Berger, J.; Butz, E.; Caspart, R.; Chwalek, T.; Colombo, F.; De Boer, W.; Dierlamm, A.; Fink, S.; Freund, B.; Friese, R.; Giffels, M.; Gilbert, A.; Goldenzweig, P.; Haitz, D.; Hartmann, F.; Heindl, S. M.; Husemann, U.; Katkov, I.; Kudella, S.; Lobelle Pardo, P.; Mildner, H.; Mozer, M. U.; Müller, Th.; Plagge, M.; Quast, G.; Rabbertz, K.; Röcker, S.; Roscher, F.; Schröder, M.; Shvetsov, I.; Sieber, G.; Simonis, H. J.; Ulrich, R.; Wagner-Kuhr, J.; Wayand, S.; Weber, M.; Weiler, T.; Williamson, S.; Wöhrmann, C.; Wolf, R.; Anagnostou, G.; Daskalakis, G.; Geralis, T.; Giakoumopoulou, V. A.; Kyriakis, A.; Loukas, D.; Topsis-Giotis, I.; Kesisoglou, S.; Panagiotou, A.; Saoulidou, N.; Tziaferi, E.; Evangelou, I.; Flouris, G.; Foudas, C.; Kokkas, P.; Loukas, N.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Filipovic, N.; Bencze, G.; Hajdu, C.; Horvath, D.; Sikler, F.; Veszpremi, V.; Vesztergombi, G.; Zsigmond, A. J.; Beni, N.; Czellar, S.; Karancsi, J.; Makovec, A.; Molnar, J.; Szillasi, Z.; Bartók, M.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Bahinipati, S.; Choudhury, S.; Mal, P.; Mandal, K.; Nayak, A.; Sahoo, D. K.; Sahoo, N.; Swain, S. K.; Bansal, S.; Beri, S. B.; Bhatnagar, V.; Chawla, R.; Bhawandeep, U.; Kalsi, A. K.; Kaur, A.; Kaur, M.; Kumar, R.; Kumari, P.; Mehta, A.; Mittal, M.; Singh, J. B.; Walia, G.; Kumar, Ashok; Bhardwaj, A.; Choudhary, B. C.; Garg, R. B.; Keshri, S.; Malhotra, S.; Naimuddin, M.; Nishu, N.; Ranjan, K.; Sharma, R.; Sharma, V.; Bhattacharya, R.; Bhattacharya, S.; Chatterjee, K.; Dey, S.; Dutt, S.; Dutta, S.; Ghosh, S.; Majumdar, N.; Modak, A.; Mondal, K.; Mukhopadhyay, S.; Nandan, S.; Purohit, A.; Roy, A.; Roy, D.; Roy Chowdhury, S.; Sarkar, S.; Sharan, M.; Thakur, S.; Behera, P. K.; Chudasama, R.; Dutta, D.; Jha, V.; Kumar, V.; Mohanty, A. K.; Netrakanti, P. K.; Pant, L. M.; Shukla, P.; Topkar, A.; Aziz, T.; Dugad, S.; Kole, G.; Mahakud, B.; Mitra, S.; Mohanty, G. B.; Parida, B.; Sur, N.; Sutar, B.; Banerjee, S.; Bhowmik, S.; Dewanjee, R. K.; Ganguly, S.; Guchait, M.; Jain, Sa.; Kumar, S.; Maity, M.; Majumder, G.; Mazumdar, K.; Sarkar, T.; Wickramage, N.; Chauhan, S.; Dube, S.; Hegde, V.; Kapoor, A.; Kothekar, K.; Pandey, S.; Rane, A.; Sharma, S.; Behnamian, H.; Chenarani, S.; Eskandari Tadavani, E.; Etesami, S. M.; Fahim, A.; Khakzad, M.; Mohammadi Najafabadi, M.; Naseri, M.; Paktinat Mehdiabadi, S.; Rezaei Hosseinabadi, F.; Safarzadeh, B.; Zeinali, M.; Felcini, M.; Grunewald, M.; Abbrescia, M.; Calabria, C.; Caputo, C.; Colaleo, A.; Creanza, D.; Cristella, L.; De Filippis, N.; De Palma, M.; Fiore, L.; Iaselli, G.; Maggi, G.; Maggi, M.; Miniello, G.; My, S.; Nuzzo, S.; Pompili, A.; Pugliese, G.; Radogna, R.; Ranieri, A.; Selvaggi, G.; Silvestris, L.; Venditti, R.; Verwilligen, P.; Abbiendi, G.; Battilana, C.; Bonacorsi, D.; Braibant-Giacomelli, S.; Brigliadori, L.; Campanini, R.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Chhibra, S. S.; Codispoti, G.; Cuffiani, M.; Dallavalle, G. M.; Fabbri, F.; Fanfani, A.; Fasanella, D.; Giacomelli, P.; Grandi, C.; Guiducci, L.; Marcellini, S.; Masetti, G.; Montanari, A.; Navarria, F. L.; Perrotta, A.; Rossi, A. M.; Rovelli, T.; Siroli, G. P.; Tosi, N.; Albergo, S.; Costa, S.; Di Mattia, A.; Giordano, F.; Potenza, R.; Tricomi, A.; Tuve, C.; Barbagli, G.; Ciulli, V.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Lenzi, P.; Meschini, M.; Paoletti, S.; Sguazzoni, G.; Viliani, L.; Benussi, L.; Bianco, S.; Fabbri, F.; Piccolo, D.; Primavera, F.; Calvelli, V.; Ferro, F.; Lo Vetere, M.; Monge, M. R.; Robutti, E.; Tosi, S.; Brianza, L.; Dinardo, M. E.; Fiorendi, S.; Gennai, S.; Ghezzi, A.; Govoni, P.; Malberti, M.; Malvezzi, S.; Manzoni, R. A.; Menasce, D.; Moroni, L.; Paganoni, M.; Pedrini, D.; Pigazzini, S.; Ragazzi, S.; Tabarelli de Fatis, T.; Buontempo, S.; Cavallo, N.; De Nardo, G.; Di Guida, S.; Esposito, M.; Fabozzi, F.; Fienga, F.; Iorio, A. O. M.; Lanza, G.; Lista, L.; Meola, S.; Paolucci, P.; Sciacca, C.; Thyssen, F.; Azzi, P.; Bacchetta, N.; Benato, L.; Bisello, D.; Boletti, A.; Carlin, R.; Carvalho Antunes De Oliveira, A.; Checchia, P.; Dall'Osso, M.; De Castro Manzano, P.; Dorigo, T.; Dosselli, U.; Gasparini, F.; Gasparini, U.; Gozzelino, A.; Lacaprara, S.; Margoni, M.; Meneguzzo, A. T.; Pazzini, J.; Pozzobon, N.; Ronchese, P.; Simonetto, F.; Torassa, E.; Zanetti, M.; Zotto, P.; Zumerle, G.; Braghieri, A.; Magnani, A.; Montagna, P.; Ratti, S. P.; Re, V.; Riccardi, C.; Salvini, P.; Vai, I.; Vitulo, P.; Alunni Solestizi, L.; Bilei, G. M.; Ciangottini, D.; Fanò, L.; Lariccia, P.; Leonardi, R.; Mantovani, G.; Menichelli, M.; Saha, A.; Santocchia, A.; Androsov, K.; Azzurri, P.; Bagliesi, G.; Bernardini, J.; Boccali, T.; Castaldi, R.; Ciocci, M. A.; Dell'Orso, R.; Donato, S.; Fedi, G.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Lomtadze, T.; Martini, L.; Messineo, A.; Palla, F.; Rizzi, A.; Savoy-Navarro, A.; Spagnolo, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Barone, L.; Cavallari, F.; Cipriani, M.; Del Re, D.; Diemoz, M.; Gelli, S.; Longo, E.; Margaroli, F.; Marzocchi, B.; Meridiani, P.; Organtini, G.; Paramatti, R.; Preiato, F.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Amapane, N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Bartosik, N.; Bellan, R.; Biino, C.; Cartiglia, N.; Cenna, F.; Costa, M.; Covarelli, R.; Degano, A.; Demaria, N.; Finco, L.; Kiani, B.; Mariotti, C.; Maselli, S.; Migliore, E.; Monaco, V.; Monteil, E.; Monteno, M.; Obertino, M. M.; Pacher, L.; Pastrone, N.; Pelliccioni, M.; Pinna Angioni, G. L.; Ravera, F.; Romero, A.; Ruspa, M.; Sacchi, R.; Shchelina, K.; Sola, V.; Solano, A.; Staiano, A.; Traczyk, P.; Belforte, S.; Casarsa, M.; Cossutti, F.; Della Ricca, G.; Zanetti, A.; Kim, D. H.; Kim, G. N.; Kim, M. S.; Lee, S.; Lee, S. W.; Oh, Y. D.; Sekmen, S.; Son, D. C.; Yang, Y. C.; Lee, A.; Kim, H.; Brochero Cifuentes, J. A.; Kim, T. J.; Cho, S.; Choi, S.; Go, Y.; Gyun, D.; Ha, S.; Hong, B.; Jo, Y.; Kim, Y.; Lee, B.; Lee, K.; Lee, K. S.; Lee, S.; Lim, J.; Park, S. K.; Roh, Y.; Almond, J.; Kim, J.; Lee, H.; Oh, S. B.; Radburn-Smith, B. C.; Seo, S. h.; Yang, U. K.; Yoo, H. D.; Yu, G. B.; Choi, M.; Kim, H.; Kim, J. H.; Lee, J. S. H.; Park, I. C.; Ryu, G.; Ryu, M. S.; Choi, Y.; Goh, J.; Hwang, C.; Lee, J.; Yu, I.; Dudenas, V.; Juodagalvis, A.; Vaitkus, J.; Ahmed, I.; Ibrahim, Z. A.; Komaragiri, J. R.; Md Ali, M. A. B.; Mohamad Idris, F.; Wan Abdullah, W. A. T.; Yusli, M. N.; Zolkapli, Z.; Castilla-Valdez, H.; De La Cruz-Burelo, E.; Heredia-De La Cruz, I.; Hernandez-Almada, A.; Lopez-Fernandez, R.; Magaña Villalba, R.; Mejia Guisao, J.; Sanchez-Hernandez, A.; Carrillo Moreno, S.; Oropeza Barrera, C.; Vazquez Valencia, F.; Carpinteyro, S.; Pedraza, I.; Salazar Ibarguen, H. A.; Uribe Estrada, C.; Morelos Pineda, A.; Krofcheck, D.; Butler, P. H.; Ahmad, A.; Ahmad, M.; Hassan, Q.; Hoorani, H. R.; Khan, W. A.; Saddique, A.; Shah, M. A.; Shoaib, M.; Waqas, M.; Bialkowska, H.; Bluj, M.; Boimska, B.; Frueboes, T.; Górski, M.; Kazana, M.; Nawrocki, K.; Romanowska-Rybinska, K.; Szleper, M.; Zalewski, P.; Bunkowski, K.; Byszuk, A.; Doroba, K.; Kalinowski, A.; Konecki, M.; Krolikowski, J.; Misiura, M.; Olszewski, M.; Walczak, M.; Bargassa, P.; Beirão Da Cruz E Silva, C.; Calpas, B.; Di Francesco, A.; Faccioli, P.; Ferreira Parracho, P. G.; Gallinaro, M.; Hollar, J.; Leonardo, N.; Lloret Iglesias, L.; Nemallapudi, M. V.; Rodrigues Antunes, J.; Seixas, J.; Toldaiev, O.; Vadruccio, D.; Varela, J.; Vischia, P.; Afanasiev, S.; Bunin, P.; Gavrilenko, M.; Golutvin, I.; Gorbunov, I.; Kamenev, A.; Karjavin, V.; Lanev, A.; Malakhov, A.; Matveev, V.; Palichik, V.; Perelygin, V.; Shmatov, S.; Shulha, S.; Skatchkov, N.; Smirnov, V.; Voytishin, N.; Zarubin, A.; Chtchipounov, L.; Golovtsov, V.; Ivanov, Y.; Kim, V.; Kuznetsova, E.; Murzin, V.; Oreshkin, V.; Sulimov, V.; Vorobyev, A.; Andreev, Yu.; Dermenev, A.; Gninenko, S.; Golubev, N.; Karneyeu, A.; Kirsanov, M.; Krasnikov, N.; Pashenkov, A.; Tlisov, D.; Toropin, A.; Epshteyn, V.; Gavrilov, V.; Lychkovskaya, N.; Popov, V.; Pozdnyakov, I.; Safronov, G.; Spiridonov, A.; Toms, M.; Vlasov, E.; Zhokin, A.; Bylinkin, A.; Markin, O.; Tarkovskii, E.; Andreev, V.; Azarkin, M.; Dremin, I.; Kirakosyan, M.; Leonidov, A.; Terkulov, A.; Baskakov, A.; Belyaev, A.; Boos, E.; Ershov, A.; Gribushin, A.; Kaminskiy, A.; Kodolova, O.; Korotkikh, V.; Lokhtin, I.; Miagkov, I.; Obraztsov, S.; Petrushanko, S.; Savrin, V.; Snigirev, A.; Vardanyan, I.; Blinov, V.; Skovpen, Y.; Shtol, D.; Azhgirey, I.; Bayshev, I.; Bitioukov, S.; Elumakhov, D.; Kachanov, V.; Kalinin, A.; Konstantinov, D.; Krychkine, V.; Petrov, V.; Ryutin, R.; Sobol, A.; Troshin, S.; Tyurin, N.; Uzunian, A.; Volkov, A.; Adzic, P.; Cirkovic, P.; Devetak, D.; Dordevic, M.; Milosevic, J.; Rekovic, V.; Alcaraz Maestre, J.; Barrio Luna, M.; Calvo, E.; Cerrada, M.; Chamizo Llatas, M.; Colino, N.; De La Cruz, B.; Delgado Peris, A.; Escalante Del Valle, A.; Fernandez Bedoya, C.; Fernández Ramos, J. P.; Flix, J.; Fouz, M. C.; Garcia-Abia, P.; Gonzalez Lopez, O.; Goy Lopez, S.; Hernandez, J. M.; Josa, M. I.; Navarro De Martino, E.; Pérez-Calero Yzquierdo, A.; Puerta Pelayo, J.; Quintario Olmeda, A.; Redondo, I.; Romero, L.; Soares, M. S.; de Trocóniz, J. F.; Missiroli, M.; Moran, D.; Cuevas, J.; Fernandez Menendez, J.; Gonzalez Caballero, I.; González Fernández, J. R.; Palencia Cortezon, E.; Sanchez Cruz, S.; Suárez Andrés, I.; Vizan Garcia, J. M.; Cabrillo, I. J.; Calderon, A.; Castiñeiras De Saa, J. R.; Curras, E.; Fernandez, M.; Garcia-Ferrero, J.; Gomez, G.; Lopez Virto, A.; Marco, J.; Martinez Rivero, C.; Matorras, F.; Piedra Gomez, J.; Rodrigo, T.; Ruiz-Jimeno, A.; Scodellaro, L.; Trevisani, N.; Vila, I.; Vilar Cortabitarte, R.; Abbaneo, D.; Auffray, E.; Auzinger, G.; Bachtis, M.; Baillon, P.; Ball, A. H.; Barney, D.; Bloch, P.; Bocci, A.; Bonato, A.; Botta, C.; Camporesi, T.; Castello, R.; Cepeda, M.; Cerminara, G.; D'Alfonso, M.; d'Enterria, D.; Dabrowski, A.; Daponte, V.; David, A.; De Gruttola, M.; De Roeck, A.; Di Marco, E.; Dobson, M.; Dorney, B.; du Pree, T.; Duggan, D.; Dünser, M.; Dupont, N.; Elliott-Peisert, A.; Fartoukh, S.; Franzoni, G.; Fulcher, J.; Funk, W.; Gigi, D.; Gill, K.; Girone, M.; Glege, F.; Gulhan, D.; Gundacker, S.; Guthoff, M.; Hammer, J.; Harris, P.; Hegeman, J.; Innocente, V.; Janot, P.; Kieseler, J.; Kirschenmann, H.; Knünz, V.; Kornmayer, A.; Kortelainen, M. J.; Kousouris, K.; Krammer, M.; Lange, C.; Lecoq, P.; Lourenço, C.; Lucchini, M. T.; Malgeri, L.; Mannelli, M.; Martelli, A.; Meijers, F.; Merlin, J. A.; Mersi, S.; Meschi, E.; Milenovic, P.; Moortgat, F.; Morovic, S.; Mulders, M.; Neugebauer, H.; Orfanelli, S.; Orsini, L.; Pape, L.; Perez, E.; Peruzzi, M.; Petrilli, A.; Petrucciani, G.; Pfeiffer, A.; Pierini, M.; Racz, A.; Reis, T.; Rolandi, G.; Rovere, M.; Ruan, M.; Sakulin, H.; Sauvan, J. B.; Schäfer, C.; Schwick, C.; Seidel, M.; Sharma, A.; Silva, P.; Sphicas, P.; Steggemann, J.; Stoye, M.; Takahashi, Y.; Tosi, M.; Treille, D.; Triossi, A.; Tsirou, A.; Veckalns, V.; Veres, G. I.; Verweij, M.; Wardle, N.; Wöhri, H. K.; Zagozdzinska, A.; Zeuner, W. D.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; Kotlinski, D.; Langenegger, U.; Rohe, T.; Bachmair, F.; Bäni, L.; Bianchini, L.; Casal, B.; Dissertori, G.; Dittmar, M.; Donegà, M.; Grab, C.; Heidegger, C.; Hits, D.; Hoss, J.; Kasieczka, G.; Lecomte, P.; Lustermann, W.; Mangano, B.; Marionneau, M.; Martinez Ruiz del Arbol, P.; Masciovecchio, M.; Meinhard, M. T.; Meister, D.; Micheli, F.; Musella, P.; Nessi-Tedaldi, F.; Pandolfi, F.; Pata, J.; Pauss, F.; Perrin, G.; Perrozzi, L.; Quittnat, M.; Rossini, M.; Schönenberger, M.; Starodumov, A.; Tavolaro, V. R.; Theofilatos, K.; Wallny, R.; Aarrestad, T. K.; Amsler, C.; Caminada, L.; Canelli, M. F.; De Cosa, A.; Galloni, C.; Hinzmann, A.; Hreus, T.; Kilminster, B.; Ngadiuba, J.; Pinna, D.; Rauco, G.; Robmann, P.; Salerno, D.; Yang, Y.; Zucchetta, A.; Candelise, V.; Doan, T. H.; Jain, Sh.; Khurana, R.; Konyushikhin, M.; Kuo, C. M.; Lin, W.; Lu, Y. J.; Pozdnyakov, A.; Yu, S. S.; Kumar, Arun; Chang, P.; Chang, Y. H.; Chang, Y. W.; Chao, Y.; Chen, K. F.; Chen, P. H.; Dietz, C.; Fiori, F.; Hou, W.-S.; Hsiung, Y.; Liu, Y. F.; Lu, R.-S.; Miñano Moya, M.; Paganis, E.; Psallidas, A.; Tsai, J. f.; Tzeng, Y. M.; Asavapibhop, B.; Singh, G.; Srimanobhas, N.; Suwonjandee, N.; Adiguzel, A.; Cerci, S.; Damarseckin, S.; Demiroglu, Z. S.; Dozen, C.; Dumanoglu, I.; Girgis, S.; Gokbulut, G.; Guler, Y.; Hos, I.; Kangal, E. E.; Kara, O.; Kayis Topaksu, A.; Kiminsu, U.; Oglakci, M.; Onengut, G.; Ozdemir, K.; Sunar Cerci, D.; Tali, B.; Turkcapar, S.; Zorbakir, I. S.; Zorbilmez, C.; Bilin, B.; Bilmis, S.; Isildak, B.; Karapinar, G.; Yalvac, M.; Zeyrek, M.; Gülmez, E.; Kaya, M.; Kaya, O.; Yetkin, E. A.; Yetkin, T.; Cakir, A.; Cankocak, K.; Sen, S.; Grynyov, B.; Levchuk, L.; Sorokin, P.; Aggleton, R.; Ball, F.; Beck, L.; Brooke, J. J.; Burns, D.; Clement, E.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Heath, G. P.; Heath, H. F.; Jacob, J.; Kreczko, L.; Lucas, C.; Newbold, D. M.; Paramesvaran, S.; Poll, A.; Sakuma, T.; Seif El Nasr-storey, S.; Smith, D.; Smith, V. J.; Belyaev, A.; Brew, C.; Brown, R. M.; Calligaris, L.; Cieri, D.; Cockerill, D. J. A.; Coughlan, J. A.; Harder, K.; Harper, S.; Olaiya, E.; Petyt, D.; Shepherd-Themistocleous, C. H.; Thea, A.; Tomalin, I. R.; Williams, T.; Baber, M.; Bainbridge, R.; Buchmuller, O.; Bundock, A.; Burton, D.; Casasso, S.; Citron, M.; Colling, D.; Corpe, L.; Dauncey, P.; Davies, G.; De Wit, A.; Della Negra, M.; Di Maria, R.; Dunne, P.; Elwood, A.; Futyan, D.; Haddad, Y.; Hall, G.; Iles, G.; James, T.; Lane, R.; Laner, C.; Lucas, R.; Lyons, L.; Magnan, A.-M.; Malik, S.; Mastrolorenzo, L.; Nash, J.; Nikitenko, A.; Pela, J.; Penning, B.; Pesaresi, M.; Raymond, D. M.; Richards, A.; Rose, A.; Seez, C.; Summers, S.; Tapper, A.; Uchida, K.; Vazquez Acosta, M.; Virdee, T.; Wright, J.; Zenz, S. C.; Cole, J. E.; Hobson, P. R.; Khan, A.; Kyberd, P.; Leslie, D.; Reid, I. D.; Symonds, P.; Teodorescu, L.; Turner, M.; Borzou, A.; Call, K.; Dittmann, J.; Hatakeyama, K.; Liu, H.; Pastika, N.; Cooper, S. I.; Henderson, C.; Rumerio, P.; West, C.; Arcaro, D.; Avetisyan, A.; Bose, T.; Gastler, D.; Rankin, D.; Richardson, C.; Rohlf, J.; Sulak, L.; Zou, D.; Benelli, G.; Berry, E.; Cutts, D.; Garabedian, A.; Hakala, J.; Heintz, U.; Hogan, J. M.; Jesus, O.; Kwok, K. H. M.; Laird, E.; Landsberg, G.; Mao, Z.; Narain, M.; Piperov, S.; Sagir, S.; Spencer, E.; Syarif, R.; Breedon, R.; Breto, G.; Burns, D.; Calderon De La Barca Sanchez, M.; Chauhan, S.; Chertok, M.; Conway, J.; Conway, R.; Cox, P. T.; Erbacher, R.; Flores, C.; Funk, G.; Gardner, M.; Ko, W.; Lander, R.; Mclean, C.; Mulhearn, M.; Pellett, D.; Pilot, J.; Shalhout, S.; Smith, J.; Squires, M.; Stolp, D.; Tripathi, M.; Bravo, C.; Cousins, R.; Dasgupta, A.; Everaerts, P.; Florent, A.; Hauser, J.; Ignatenko, M.; Mccoll, N.; Saltzberg, D.; Schnaible, C.; Takasugi, E.; Valuev, V.; Weber, M.; Burt, K.; Clare, R.; Ellison, J.; Gary, J. W.; Ghiasi Shirazi, S. M. A.; Hanson, G.; Heilman, J.; Jandir, P.; Kennedy, E.; Lacroix, F.; Long, O. R.; Olmedo Negrete, M.; Paneva, M. I.; Shrinivas, A.; Si, W.; Wei, H.; Wimpenny, S.; Yates, B. R.; Branson, J. G.; Cerati, G. B.; Cittolin, S.; Derdzinski, M.; Holzner, A.; Klein, D.; Krutelyov, V.; Letts, J.; Macneill, I.; Olivito, D.; Padhi, S.; Pieri, M.; Sani, M.; Sharma, V.; Simon, S.; Tadel, M.; Vartak, A.; Wasserbaech, S.; Welke, C.; Wood, J.; Würthwein, F.; Yagil, A.; Zevi Della Porta, G.; Amin, N.; Bhandari, R.; Bradmiller-Feld, J.; Campagnari, C.; Dishaw, A.; Dutta, V.; Franco Sevilla, M.; George, C.; Golf, F.; Gouskos, L.; Gran, J.; Heller, R.; Incandela, J.; Mullin, S. D.; Ovcharova, A.; Qu, H.; Richman, J.; Stuart, D.; Suarez, I.; Yoo, J.; Anderson, D.; Apresyan, A.; Bendavid, J.; Bornheim, A.; Bunn, J.; Chen, Y.; Duarte, J.; Lawhorn, J. M.; Mott, A.; Newman, H. B.; Pena, C.; Spiropulu, M.; Vlimant, J. R.; Xie, S.; Zhu, R. Y.; Andrews, M. B.; Azzolini, V.; Ferguson, T.; Paulini, M.; Russ, J.; Sun, M.; Vogel, H.; Vorobiev, I.; Weinberg, M.; Cumalat, J. P.; Ford, W. T.; Jensen, F.; Johnson, A.; Krohn, M.; Mulholland, T.; Stenson, K.; Wagner, S. R.; Alexander, J.; Chaves, J.; Chu, J.; Dittmer, S.; Mcdermott, K.; Mirman, N.; Nicolas Kaufman, G.; Patterson, J. R.; Rinkevicius, A.; Ryd, A.; Skinnari, L.; Soffi, L.; Tan, S. M.; Tao, Z.; Thom, J.; Tucker, J.; Wittich, P.; Zientek, M.; Winn, D.; Abdullin, S.; Albrow, M.; Apollinari, G.; Banerjee, S.; Bauerdick, L. A. T.; Beretvas, A.; Berryhill, J.; Bhat, P. C.; Bolla, G.; Burkett, K.; Butler, J. N.; Cheung, H. W. K.; Chlebana, F.; Cihangir, S.; Cremonesi, M.; Elvira, V. D.; Fisk, I.; Freeman, J.; Gottschalk, E.; Gray, L.; Green, D.; Grünendahl, S.; Gutsche, O.; Hare, D.; Harris, R. M.; Hasegawa, S.; Hirschauer, J.; Hu, Z.; Jayatilaka, B.; Jindariani, S.; Johnson, M.; Joshi, U.; Klima, B.; Kreis, B.; Lammel, S.; Linacre, J.; Lincoln, D.; Lipton, R.; Liu, T.; Lopes De Sá, R.; Lykken, J.; Maeshima, K.; Magini, N.; Marraffino, J. M.; Maruyama, S.; Mason, D.; McBride, P.; Merkel, P.; Mrenna, S.; Nahn, S.; Newman-Holmes, C.; O'Dell, V.; Pedro, K.; Prokofyev, O.; Rakness, G.; Ristori, L.; Sexton-Kennedy, E.; Soha, A.; Spalding, W. J.; Spiegel, L.; Stoynev, S.; Strobbe, N.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vernieri, C.; Verzocchi, M.; Vidal, R.; Wang, M.; Weber, H. A.; Whitbeck, A.; Wu, Y.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Brinkerhoff, A.; Carnes, A.; Carver, M.; Curry, D.; Das, S.; Field, R. D.; Furic, I. K.; Konigsberg, J.; Korytov, A.; Low, J. F.; Ma, P.; Matchev, K.; Mei, H.; Mitselmakher, G.; Rank, D.; Shchutska, L.; Sperka, D.; Thomas, L.; Wang, J.; Wang, S.; Yelton, J.; Linn, S.; Markowitz, P.; Martinez, G.; Rodriguez, J. L.; Ackert, A.; Adams, J. R.; Adams, T.; Askew, A.; Bein, S.; Diamond, B.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Khatiwada, A.; Prosper, H.; Santra, A.; Yohay, R.; Baarmand, M. M.; Bhopatkar, V.; Colafranceschi, S.; Hohlmann, M.; Noonan, D.; Roy, T.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Bucinskaite, I.; Cavanaugh, R.; Evdokimov, O.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Jung, K.; Kurt, P.; O'Brien, C.; Sandoval Gonzalez, I. D.; Turner, P.; Varelas, N.; Wang, H.; Wu, Z.; Zakaria, M.; Zhang, J.; Bilki, B.; Clarida, W.; Dilsiz, K.; Durgut, S.; Gandrajula, R. P.; Haytmyradov, M.; Khristenko, V.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Snyder, C.; Tiras, E.; Wetzel, J.; Yi, K.; Anderson, I.; Blumenfeld, B.; Cocoros, A.; Eminizer, N.; Fehling, D.; Feng, L.; Gritsan, A. V.; Maksimovic, P.; Martin, C.; Osherson, M.; Roskes, J.; Sarica, U.; Swartz, M.; Xiao, M.; Xin, Y.; You, C.; Al-bataineh, A.; Baringer, P.; Bean, A.; Boren, S.; Bowen, J.; Bruner, C.; Castle, J.; Forthomme, L.; Kenny, R. P.; Khalil, S.; Kropivnitskaya, A.; Majumder, D.; Mcbrayer, W.; Murray, M.; Sanders, S.; Stringer, R.; Tapia Takaki, J. D.; Wang, Q.; Ivanov, A.; Kaadze, K.; Maravin, Y.; Mohammadi, A.; Saini, L. K.; Skhirtladze, N.; Toda, S.; Rebassoo, F.; Wright, D.; Anelli, C.; Baden, A.; Baron, O.; Belloni, A.; Calvert, B.; Eno, S. C.; Ferraioli, C.; Gomez, J. A.; Hadley, N. J.; Jabeen, S.; Kellogg, R. G.; Kolberg, T.; Kunkle, J.; Lu, Y.; Mignerey, A. C.; Ricci-Tam, F.; Shin, Y. H.; Skuja, A.; Tonjes, M. B.; Tonwar, S. C.; Abercrombie, D.; Allen, B.; Apyan, A.; Barbieri, R.; Baty, A.; Bi, R.; Bierwagen, K.; Brandt, S.; Busza, W.; Cali, I. A.; Demiragli, Z.; Di Matteo, L.; Gomez Ceballos, G.; Goncharov, M.; Hsu, D.; Iiyama, Y.; Innocenti, G. M.; Klute, M.; Kovalskyi, D.; Krajczar, K.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Maier, B.; Marini, A. C.; Mcginn, C.; Mironov, C.; Narayanan, S.; Niu, X.; Paus, C.; Roland, C.; Roland, G.; Salfeld-Nebgen, J.; Stephans, G. S. F.; Sumorok, K.; Tatar, K.; Varma, M.; Velicanu, D.; Veverka, J.; Wang, J.; Wang, T. W.; Wyslouch, B.; Yang, M.; Zhukova, V.; Benvenuti, A. C.; Chatterjee, R. M.; Evans, A.; Finkel, A.; Gude, A.; Hansen, P.; Kalafut, S.; Kao, S. C.; Kubota, Y.; Lesko, Z.; Mans, J.; Nourbakhsh, S.; Ruckstuhl, N.; Rusack, R.; Tambe, N.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bartek, R.; Bloom, K.; Claes, D. R.; Dominguez, A.; Fangmeier, C.; Gonzalez Suarez, R.; Kamalieddin, R.; Kravchenko, I.; Malta Rodrigues, A.; Meier, F.; Monroy, J.; Siado, J. E.; Snow, G. R.; Stieger, B.; Alyari, M.; Dolen, J.; George, J.; Godshalk, A.; Harrington, C.; Iashvili, I.; Kaisen, J.; Kharchilava, A.; Kumar, A.; Parker, A.; Rappoccio, S.; Roozbahani, B.; Alverson, G.; Barberis, E.; Hortiangtham, A.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; Teixeira De Lima, R.; Trocino, D.; Wang, R.-J.; Wood, D.; Bhattacharya, S.; Charaf, O.; Hahn, K. A.; Kubik, A.; Kumar, A.; Mucia, N.; Odell, N.; Pollack, B.; Schmitt, M. H.; Sung, K.; Trovato, M.; Velasco, M.; Dev, N.; Hildreth, M.; Hurtado Anampa, K.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Marinelli, N.; Meng, F.; Mueller, C.; Musienko, Y.; Planer, M.; Reinsvold, A.; Ruchti, R.; Smith, G.; Taroni, S.; Wayne, M.; Wolf, M.; Woodard, A.; Alimena, J.; Antonelli, L.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Francis, B.; Hart, A.; Hill, C.; Hughes, R.; Ji, W.; Liu, B.; Luo, W.; Puigh, D.; Winer, B. L.; Wulsin, H. W.; Cooperstein, S.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Lange, D.; Luo, J.; Marlow, D.; Mc Donald, J.; Medvedeva, T.; Mei, K.; Mooney, M.; Olsen, J.; Palmer, C.; Piroué, P.; Stickland, D.; Svyatkovskiy, A.; Tully, C.; Zuranski, A.; Malik, S.; Barker, A.; Barnes, V. E.; Folgueras, S.; Gutay, L.; Jha, M. K.; Jones, M.; Jung, A. W.; Miller, D. H.; Neumeister, N.; Schulte, J. F.; Shi, X.; Sun, J.; Wang, F.; Xie, W.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Chen, Z.; Ecklund, K. M.; Geurts, F. J. M.; Guilbaud, M.; Li, W.; Michlin, B.; Northup, M.; Padley, B. P.; Redjimi, R.; Roberts, J.; Rorie, J.; Tu, Z.; Zabel, J.; Betchart, B.; Bodek, A.; de Barbaro, P.; Demina, R.; Duh, Y. t.; Ferbel, T.; Galanti, M.; Garcia-Bellido, A.; Han, J.; Hindrichs, O.; Khukhunaishvili, A.; Lo, K. H.; Tan, P.; Verzetti, M.; Agapitos, A.; Chou, J. P.; Contreras-Campana, E.; Gershtein, Y.; Gómez Espinosa, T. A.; Halkiadakis, E.; Heindl, M.; Hidas, D.; Hughes, E.; Kaplan, S.; Kunnawalkam Elayavalli, R.; Kyriacou, S.; Lath, A.; Nash, K.; Saka, H.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Delannoy, A. G.; Foerster, M.; Heideman, J.; Riley, G.; Rose, K.; Spanier, S.; Thapa, K.; Bouhali, O.; Celik, A.; Dalchenko, M.; De Mattia, M.; Delgado, A.; Dildick, S.; Eusebi, R.; Gilmore, J.; Huang, T.; Juska, E.; Kamon, T.; Mueller, R.; Pakhotin, Y.; Patel, R.; Perloff, A.; Perniè, L.; Rathjens, D.; Rose, A.; Safonov, A.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Cowden, C.; Damgov, J.; De Guio, F.; Dragoiu, C.; Dudero, P. R.; Faulkner, J.; Gurpinar, E.; Kunori, S.; Lamichhane, K.; Lee, S. W.; Libeiro, T.; Peltola, T.; Undleeb, S.; Volobouev, I.; Wang, Z.; Greene, S.; Gurrola, A.; Janjam, R.; Johns, W.; Maguire, C.; Melo, A.; Ni, H.; Sheldon, P.; Tuo, S.; Velkovska, J.; Xu, Q.; Arenton, M. W.; Barria, P.; Cox, B.; Goodell, J.; Hirosky, R.; Ledovskoy, A.; Li, H.; Neu, C.; Sinthuprasith, T.; Sun, X.; Wang, Y.; Wolfe, E.; Xia, F.; Clarke, C.; Harr, R.; Karchin, P. E.; Sturdy, J.; Belknap, D. A.; Buchanan, J.; Caillol, C.; Dasu, S.; Dodd, L.; Duric, S.; Gomber, B.; Grothe, M.; Herndon, M.; Hervé, A.; Klabbers, P.; Lanaro, A.; Levine, A.; Long, K.; Loveless, R.; Ojalvo, I.; Perry, T.; Pierro, G. A.; Polese, G.; Ruggles, T.; Savin, A.; Smith, N.; Smith, W. H.; Taylor, D.; Woods, N.; CMS Collaboration
2017-03-01
Charge-dependent azimuthal particle correlations with respect to the second-order event plane in p -Pb and PbPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV have been studied with the CMS experiment at the LHC. The measurement is performed with a three-particle correlation technique, using two particles with the same or opposite charge within the pseudorapidity range |η | <2.4 , and a third particle measured in the hadron forward calorimeters (4.4 <|η | <5 ). The observed differences between the same and opposite sign correlations, as functions of multiplicity and η gap between the two charged particles, are of similar magnitude in p -Pb and PbPb collisions at the same multiplicities. These results pose a challenge for the interpretation of charge-dependent azimuthal correlations in heavy ion collisions in terms of the chiral magnetic effect.
Khachatryan, V; Sirunyan, A M; Tumasyan, A; Adam, W; Asilar, E; Bergauer, T; Brandstetter, J; Brondolin, E; Dragicevic, M; Erö, J; Flechl, M; Friedl, M; Frühwirth, R; Ghete, V M; Hartl, C; Hörmann, N; Hrubec, J; Jeitler, M; König, A; Krätschmer, I; Liko, D; Matsushita, T; Mikulec, I; Rabady, D; Rad, N; Rahbaran, B; Rohringer, H; Schieck, J; Strauss, J; Waltenberger, W; Wulz, C-E; Dvornikov, O; Makarenko, V; Zykunov, V; Mossolov, V; Shumeiko, N; Suarez Gonzalez, J; Alderweireldt, S; De Wolf, E A; Janssen, X; Lauwers, J; Van De Klundert, M; Van Haevermaet, H; Van Mechelen, P; Van Remortel, N; Van Spilbeeck, A; Abu Zeid, S; Blekman, F; D'Hondt, J; Daci, N; De Bruyn, I; Deroover, K; Lowette, S; Moortgat, S; Moreels, L; Olbrechts, A; Python, Q; Tavernier, S; Van Doninck, W; Van Mulders, P; Van Parijs, I; Brun, H; Clerbaux, B; De Lentdecker, G; Delannoy, H; Fasanella, G; Favart, L; Goldouzian, R; Grebenyuk, A; Karapostoli, G; Lenzi, T; Léonard, A; Luetic, J; Maerschalk, T; Marinov, A; Randle-Conde, A; Seva, T; Vander Velde, C; Vanlaer, P; Vannerom, D; Yonamine, R; Zenoni, F; Zhang, F; Cimmino, A; Cornelis, T; Dobur, D; Fagot, A; Garcia, G; Gul, M; Khvastunov, I; Poyraz, D; Salva, S; Schöfbeck, R; Sharma, A; Tytgat, M; Van Driessche, W; Yazgan, E; Zaganidis, N; Bakhshiansohi, H; Beluffi, C; Bondu, O; Brochet, S; Bruno, G; Caudron, A; De Visscher, S; Delaere, C; Delcourt, M; Francois, B; Giammanco, A; Jafari, A; Jez, P; Komm, M; Krintiras, G; Lemaitre, V; Magitteri, A; Mertens, A; Musich, M; Nuttens, C; Piotrzkowski, K; Quertenmont, L; Selvaggi, M; Vidal Marono, M; Wertz, S; Beliy, N; Aldá Júnior, W L; Alves, F L; Alves, G A; Brito, L; Hensel, C; Moraes, A; Pol, M E; Rebello Teles, P; Belchior Batista Das Chagas, E; Carvalho, W; Chinellato, J; Custódio, A; Da Costa, E M; Da Silveira, G G; De Jesus Damiao, D; De Oliveira Martins, C; Fonseca De Souza, S; Huertas Guativa, L M; Malbouisson, H; Matos Figueiredo, D; Mora Herrera, C; Mundim, L; Nogima, H; Prado Da Silva, W L; Santoro, A; Sznajder, A; Tonelli Manganote, E J; Vilela Pereira, A; Ahuja, S; Bernardes, C A; Dogra, S; Fernandez Perez Tomei, T R; Gregores, E M; Mercadante, P G; Moon, C S; Novaes, S F; Padula, Sandra S; Romero Abad, D; Ruiz Vargas, J C; Aleksandrov, A; Hadjiiska, R; Iaydjiev, P; Rodozov, M; Stoykova, S; Sultanov, G; Vutova, M; Dimitrov, A; Glushkov, I; Litov, L; Pavlov, B; Petkov, P; Fang, W; Ahmad, M; Bian, J G; Chen, G M; Chen, H S; Chen, M; Chen, Y; Cheng, T; Jiang, C H; Leggat, D; Liu, Z; Romeo, F; Shaheen, S M; Spiezia, A; Tao, J; Wang, C; Wang, Z; Zhang, H; Zhao, J; Ban, Y; Chen, G; Li, Q; Liu, S; Mao, Y; Qian, S J; Wang, D; Xu, Z; Avila, C; Cabrera, A; Chaparro Sierra, L F; Florez, C; Gomez, J P; González Hernández, C F; Ruiz Alvarez, J D; Sanabria, J C; Godinovic, N; Lelas, D; Puljak, I; Ribeiro Cipriano, P M; Sculac, T; Antunovic, Z; Kovac, M; Brigljevic, V; Ferencek, D; Kadija, K; Mesic, B; Micanovic, S; Sudic, L; Susa, T; Attikis, A; Mavromanolakis, G; Mousa, J; Nicolaou, C; Ptochos, F; Razis, P A; Rykaczewski, H; Tsiakkouri, D; Finger, M; Finger, M; Carrera Jarrin, E; Abdelalim, A A; Mohammed, Y; Salama, E; Kadastik, M; Perrini, L; Raidal, M; Tiko, A; Veelken, C; Eerola, P; Pekkanen, J; Voutilainen, M; Härkönen, J; Järvinen, T; Karimäki, V; Kinnunen, R; Lampén, T; Lassila-Perini, K; Lehti, S; Lindén, T; Luukka, P; Tuominiemi, J; Tuovinen, E; Wendland, L; Talvitie, J; Tuuva, T; Besancon, M; Couderc, F; Dejardin, M; Denegri, D; Fabbro, B; Faure, J L; Favaro, C; Ferri, F; Ganjour, S; Ghosh, S; Givernaud, A; Gras, P; Hamel de Monchenault, G; Jarry, P; Kucher, I; Locci, E; Machet, M; Malcles, J; Rander, J; Rosowsky, A; Titov, M; Zghiche, A; Abdulsalam, A; Antropov, I; Baffioni, S; Beaudette, F; Busson, P; Cadamuro, L; Chapon, E; Charlot, C; Davignon, O; Granier de Cassagnac, R; Jo, M; Lisniak, S; Miné, P; Nguyen, M; Ochando, C; Ortona, G; Paganini, P; Pigard, P; Regnard, S; Salerno, R; Sirois, Y; Strebler, T; Yilmaz, Y; Zabi, A; Agram, J-L; Andrea, J; Aubin, A; Bloch, D; Brom, J-M; Buttignol, M; Chabert, E C; Chanon, N; Collard, C; Conte, E; Coubez, X; Fontaine, J-C; Gelé, D; Goerlach, U; Le Bihan, A-C; Skovpen, K; Van Hove, P; Gadrat, S; Beauceron, S; Bernet, C; Boudoul, G; Bouvier, E; Carrillo Montoya, C A; Chierici, R; Contardo, D; Courbon, B; Depasse, P; El Mamouni, H; Fan, J; Fay, J; Gascon, S; Gouzevitch, M; Grenier, G; Ille, B; Lagarde, F; Laktineh, I B; Lethuillier, M; Mirabito, L; Pequegnot, A L; Perries, S; Popov, A; Sabes, D; Sordini, V; Vander Donckt, M; Verdier, P; Viret, S; Toriashvili, T; Tsamalaidze, Z; Autermann, C; Beranek, S; Feld, L; Heister, A; Kiesel, M K; Klein, K; Lipinski, M; Ostapchuk, A; Preuten, M; Raupach, F; Schael, S; Schomakers, C; Schulz, J; Verlage, T; Weber, H; Zhukov, V; Albert, A; Brodski, M; Dietz-Laursonn, E; Duchardt, D
2017-03-24
Charge-dependent azimuthal particle correlations with respect to the second-order event plane in p-Pb and PbPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV have been studied with the CMS experiment at the LHC. The measurement is performed with a three-particle correlation technique, using two particles with the same or opposite charge within the pseudorapidity range |η|<2.4, and a third particle measured in the hadron forward calorimeters (4.4<|η|<5). The observed differences between the same and opposite sign correlations, as functions of multiplicity and η gap between the two charged particles, are of similar magnitude in p-Pb and PbPb collisions at the same multiplicities. These results pose a challenge for the interpretation of charge-dependent azimuthal correlations in heavy ion collisions in terms of the chiral magnetic effect.
Khachatryan, Vardan; Tumasyan, Armen; Adam, Wolfgang; Aşılar, Ece; Bergauer, Thomas; Brandstetter, Johannes; Brondolin, Erica; Dragicevic, Marko; Erö, Janos; Flechl, Martin; Friedl, Markus; Fruehwirth, Rudolf; Ghete, Vasile Mihai; Hartl, Christian; Hörmann, Natascha; Hrubec, Josef; Jeitler, Manfred; König, Axel; Krätschmer, Ilse; Liko, Dietrich; Matsushita, Takashi; Mikulec, Ivan; Rabady, Dinyar; Rad, Navid; Rahbaran, Babak; Rohringer, Herbert; Schieck, Jochen; Strauss, Josef; Waltenberger, Wolfgang; Wulz, Claudia-Elisabeth; Dvornikov, Oleg; Makarenko, Vladimir; Zykunov, Vladimir; Mossolov, Vladimir; Shumeiko, Nikolai; Suarez Gonzalez, Juan; Alderweireldt, Sara; De Wolf, Eddi A; Janssen, Xavier; Lauwers, Jasper; Van De Klundert, Merijn; Van Haevermaet, Hans; Van Mechelen, Pierre; Van Remortel, Nick; Van Spilbeeck, Alex; Abu Zeid, Shimaa; Blekman, Freya; D'Hondt, Jorgen; Daci, Nadir; De Bruyn, Isabelle; Deroover, Kevin; Lowette, Steven; Moortgat, Seth; Moreels, Lieselotte; Olbrechts, Annik; Python, Quentin; Tavernier, Stefaan; Van Doninck, Walter; Van Mulders, Petra; Van Parijs, Isis; Brun, Hugues; Clerbaux, Barbara; De Lentdecker, Gilles; Delannoy, Hugo; Fasanella, Giuseppe; Favart, Laurent; Goldouzian, Reza; Grebenyuk, Anastasia; Karapostoli, Georgia; Lenzi, Thomas; Léonard, Alexandre; Luetic, Jelena; Maerschalk, Thierry; Marinov, Andrey; Randle-conde, Aidan; Seva, Tomislav; Vander Velde, Catherine; Vanlaer, Pascal; Vannerom, David; Yonamine, Ryo; Zenoni, Florian; Zhang, Fengwangdong; Cimmino, Anna; Cornelis, Tom; Dobur, Didar; Fagot, Alexis; Garcia, Guillaume; Gul, Muhammad; Khvastunov, Illia; Poyraz, Deniz; Salva Diblen, Sinem; Schöfbeck, Robert; Sharma, Archana; Tytgat, Michael; Van Driessche, Ward; Yazgan, Efe; Zaganidis, Nicolas; Bakhshiansohi, Hamed; Beluffi, Camille; Bondu, Olivier; Brochet, Sébastien; Bruno, Giacomo; Caudron, Adrien; De Visscher, Simon; Delaere, Christophe; Delcourt, Martin; Francois, Brieuc; Giammanco, Andrea; Jafari, Abideh; Jez, Pavel; Komm, Matthias; Krintiras, Georgios; Lemaitre, Vincent; Magitteri, Alessio; Mertens, Alexandre; Musich, Marco; Nuttens, Claude; Piotrzkowski, Krzysztof; Quertenmont, Loic; Selvaggi, Michele; Vidal Marono, Miguel; Wertz, Sébastien; Beliy, Nikita; Aldá Júnior, Walter Luiz; Alves, Fábio Lúcio; Alves, Gilvan; Brito, Lucas; Hensel, Carsten; Moraes, Arthur; Pol, Maria Elena; Rebello Teles, Patricia; Belchior Batista Das Chagas, Ewerton; Carvalho, Wagner; Chinellato, Jose; Custódio, Analu; Melo Da Costa, Eliza; Da Silveira, Gustavo Gil; De Jesus Damiao, Dilson; De Oliveira Martins, Carley; Fonseca De Souza, Sandro; Huertas Guativa, Lina Milena; Malbouisson, Helena; Matos Figueiredo, Diego; Mora Herrera, Clemencia; Mundim, Luiz; Nogima, Helio; Prado Da Silva, Wanda Lucia; Santoro, Alberto; Sznajder, Andre; Tonelli Manganote, Edmilson José; Vilela Pereira, Antonio; Ahuja, Sudha; Bernardes, Cesar Augusto; Dogra, Sunil; Tomei, Thiago; De Moraes Gregores, Eduardo; Mercadante, Pedro G; Moon, Chang-Seong; Novaes, Sergio F; Padula, Sandra; Romero Abad, David; Ruiz Vargas, José Cupertino; Aleksandrov, Aleksandar; Hadjiiska, Roumyana; Iaydjiev, Plamen; Rodozov, Mircho; Stoykova, Stefka; Sultanov, Georgi; Vutova, Mariana; Dimitrov, Anton; Glushkov, Ivan; Litov, Leander; Pavlov, Borislav; Petkov, Peicho; Fang, Wenxing; Ahmad, Muhammad; Bian, Jian-Guo; Chen, Guo-Ming; Chen, He-Sheng; Chen, Mingshui; Chen, Ye; Cheng, Tongguang; Jiang, Chun-Hua; Leggat, Duncan; Liu, Zhenan; Romeo, Francesco; Shaheen, Sarmad Masood; Spiezia, Aniello; Tao, Junquan; Wang, Chunjie; Wang, Zheng; Zhang, Huaqiao; Zhao, Jingzhou; Ban, Yong; Chen, Geng; Li, Qiang; Liu, Shuai; Mao, Yajun; Qian, Si-Jin; Wang, Dayong; Xu, Zijun; Avila, Carlos; Cabrera, Andrés; Chaparro Sierra, Luisa Fernanda; Florez, Carlos; Gomez, Juan Pablo; González Hernández, Carlos Felipe; Ruiz Alvarez, José David; Sanabria, Juan Carlos; Godinovic, Nikola; Lelas, Damir; Puljak, Ivica; Ribeiro Cipriano, Pedro M; Sculac, Toni; Antunovic, Zeljko; Kovac, Marko; Brigljevic, Vuko; Ferencek, Dinko; Kadija, Kreso; Mesic, Benjamin; Micanovic, Sasa; Sudic, Lucija; Susa, Tatjana; Attikis, Alexandros; Mavromanolakis, Georgios; Mousa, Jehad; Nicolaou, Charalambos; Ptochos, Fotios; Razis, Panos A; Rykaczewski, Hans; Tsiakkouri, Demetra; Finger, Miroslav; Finger Jr, Michael; Carrera Jarrin, Edgar; Abdelalim, Ahmed Ali; Mohammed, Yasser; Salama, Elsayed; Kadastik, Mario; Perrini, Lucia; Raidal, Martti; Tiko, Andres; Veelken, Christian; Eerola, Paula; Pekkanen, Juska; Voutilainen, Mikko; Härkönen, Jaakko; Jarvinen, Terhi; Karimäki, Veikko; Kinnunen, Ritva; Lampén, Tapio; Lassila-Perini, Kati; Lehti, Sami; Lindén, Tomas; Luukka, Panja-Riina; Tuominiemi, Jorma; Tuovinen, Esa; Wendland, Lauri; Talvitie, Joonas; Tuuva, Tuure; Besancon, Marc; Couderc, Fabrice; Dejardin, Marc; Denegri, Daniel; Fabbro, Bernard; Faure, Jean-Louis; Favaro, Carlotta; Ferri, Federico; Ganjour, Serguei; Ghosh, Saranya; Givernaud, Alain; Gras, Philippe; Hamel de Monchenault, Gautier; Jarry, Patrick; Kucher, Inna; Locci, Elizabeth; Machet, Martina; Malcles, Julie; Rander, John; Rosowsky, André; Titov, Maksym; Zghiche, Amina; Abdulsalam, Abdulla; Antropov, Iurii; Baffioni, Stephanie; Beaudette, Florian; Busson, Philippe; Cadamuro, Luca; Chapon, Emilien; Charlot, Claude; Davignon, Olivier; Granier de Cassagnac, Raphael; Jo, Mihee; Lisniak, Stanislav; Miné, Philippe; Nguyen, Matthew; Ochando, Christophe; Ortona, Giacomo; Paganini, Pascal; Pigard, Philipp; Regnard, Simon; Salerno, Roberto; Sirois, Yves; Strebler, Thomas; Yilmaz, Yetkin; Zabi, Alexandre; Agram, Jean-Laurent; Andrea, Jeremy; Aubin, Alexandre; Bloch, Daniel; Brom, Jean-Marie; Buttignol, Michael; Chabert, Eric Christian; Chanon, Nicolas; Collard, Caroline; Conte, Eric; Coubez, Xavier; Fontaine, Jean-Charles; Gelé, Denis; Goerlach, Ulrich; Le Bihan, Anne-Catherine; Skovpen, Kirill; Van Hove, Pierre; Gadrat, Sébastien; Beauceron, Stephanie; Bernet, Colin; Boudoul, Gaelle; Bouvier, Elvire; Carrillo Montoya, Camilo Andres; Chierici, Roberto; Contardo, Didier; Courbon, Benoit; Depasse, Pierre; El Mamouni, Houmani; Fan, Jiawei; Fay, Jean; Gascon, Susan; Gouzevitch, Maxime; Grenier, Gérald; Ille, Bernard; Lagarde, Francois; Laktineh, Imad Baptiste; Lethuillier, Morgan; Mirabito, Laurent; Pequegnot, Anne-Laure; Perries, Stephane; Popov, Andrey; Sabes, David; Sordini, Viola; Vander Donckt, Muriel; Verdier, Patrice; Viret, Sébastien; Toriashvili, Tengizi; Tsamalaidze, Zviad; Autermann, Christian; Beranek, Sarah; Feld, Lutz; Heister, Arno; Kiesel, Maximilian Knut; Klein, Katja; Lipinski, Martin; Ostapchuk, Andrey; Preuten, Marius; Raupach, Frank; Schael, Stefan; Schomakers, Christian; Schulz, Johannes; Verlage, Tobias; Weber, Hendrik; Zhukov, Valery; Albert, Andreas; Brodski, Michael; Dietz-Laursonn, Erik; Duchardt, Deborah; Endres, Matthias; Erdmann, Martin; Erdweg, Sören; Esch, Thomas; Fischer, Robert; Güth, Andreas; Hamer, Matthias; Hebbeker, Thomas; Heidemann, Carsten; Hoepfner, Kerstin; Knutzen, Simon; Merschmeyer, Markus; Meyer, Arnd; Millet, Philipp; Mukherjee, Swagata; Olschewski, Mark; Padeken, Klaas; Pook, Tobias; Radziej, Markus; Reithler, Hans; Rieger, Marcel; Scheuch, Florian; Sonnenschein, Lars; Teyssier, Daniel; Thüer, Sebastian; Cherepanov, Vladimir; Flügge, Günter; Kargoll, Bastian; Kress, Thomas; Künsken, Andreas; Lingemann, Joschka; Müller, Thomas; Nehrkorn, Alexander; Nowack, Andreas; Pistone, Claudia; Pooth, Oliver; Stahl, Achim; Aldaya Martin, Maria; Arndt, Till; Asawatangtrakuldee, Chayanit; Beernaert, Kelly; Behnke, Olaf; Behrens, Ulf; Bin Anuar, Afiq Aizuddin; Borras, Kerstin; Campbell, Alan; Connor, Patrick; Contreras-Campana, Christian; Costanza, Francesco; Diez Pardos, Carmen; Dolinska, Ganna; Eckerlin, Guenter; Eckstein, Doris; Eichhorn, Thomas; Eren, Engin; Gallo, Elisabetta; Garay Garcia, Jasone; Geiser, Achim; Gizhko, Andrii; Grados Luyando, Juan Manuel; Gunnellini, Paolo; Harb, Ali; Hauk, Johannes; Hempel, Maria; Jung, Hannes; Kalogeropoulos, Alexis; Karacheban, Olena; Kasemann, Matthias; Keaveney, James; Kleinwort, Claus; Korol, Ievgen; Krücker, Dirk; Lange, Wolfgang; Lelek, Aleksandra; Leonard, Jessica; Lipka, Katerina; Lobanov, Artur; Lohmann, Wolfgang; Mankel, Rainer; Melzer-Pellmann, Isabell-Alissandra; Meyer, Andreas Bernhard; Mittag, Gregor; Mnich, Joachim; Mussgiller, Andreas; Ntomari, Eleni; Pitzl, Daniel; Placakyte, Ringaile; Raspereza, Alexei; Roland, Benoit; Sahin, Mehmet Özgür; Saxena, Pooja; Schoerner-Sadenius, Thomas; Seitz, Claudia; Spannagel, Simon; Stefaniuk, Nazar; Van Onsem, Gerrit Patrick; Walsh, Roberval; Wissing, Christoph; Blobel, Volker; Centis Vignali, Matteo; Draeger, Arne-Rasmus; Dreyer, Torben; Garutti, Erika; Gonzalez, Daniel; Haller, Johannes; Hoffmann, Malte; Junkes, Alexandra; Klanner, Robert; Kogler, Roman; Kovalchuk, Nataliia; Lapsien, Tobias; Lenz, Teresa; Marchesini, Ivan; Marconi, Daniele; Meyer, Mareike; Niedziela, Marek; Nowatschin, Dominik; Pantaleo, Felice; Peiffer, Thomas; Perieanu, Adrian; Poehlsen, Jennifer; Sander, Christian; Scharf, Christian; Schleper, Peter; Schmidt, Alexander; Schumann, Svenja; Schwandt, Joern; Stadie, Hartmut; Steinbrück, Georg; Stober, Fred-Markus Helmut; Stöver, Marc; Tholen, Heiner; Troendle, Daniel; Usai, Emanuele; Vanelderen, Lukas; Vanhoefer, Annika; Vormwald, Benedikt; Akbiyik, Melike; Barth, Christian; Baur, Sebastian; Baus, Colin; Berger, Joram; Butz, Erik; Caspart, René; Chwalek, Thorsten; Colombo, Fabio; De Boer, Wim; Dierlamm, Alexander; Fink, Simon; Freund, Benedikt; Friese, Raphael; Giffels, Manuel; Gilbert, Andrew; Goldenzweig, Pablo; Haitz, Dominik; Hartmann, Frank; Heindl, Stefan Michael; Husemann, Ulrich; Katkov, Igor; Kudella, Simon; Lobelle Pardo, Patricia; Mildner, Hannes; Mozer, Matthias Ulrich; Müller, Thomas; Plagge, Michael; Quast, Gunter; Rabbertz, Klaus; Röcker, Steffen; Roscher, Frank; Schröder, Matthias; Shvetsov, Ivan; Sieber, Georg; Simonis, Hans-Jürgen; Ulrich, Ralf; Wagner-Kuhr, Jeannine; Wayand, Stefan; Weber, Marc; Weiler, Thomas; Williamson, Shawn; Wöhrmann, Clemens; Wolf, Roger; Anagnostou, Georgios; Daskalakis, Georgios; Geralis, Theodoros; Giakoumopoulou, Viktoria Athina; Kyriakis, Aristotelis; Loukas, Demetrios; Topsis-Giotis, Iasonas; Kesisoglou, Stilianos; Panagiotou, Apostolos; Saoulidou, Niki; Tziaferi, Eirini; Evangelou, Ioannis; Flouris, Giannis; Foudas, Costas; Kokkas, Panagiotis; Loukas, Nikitas; Manthos, Nikolaos; Papadopoulos, Ioannis; Paradas, Evangelos; Filipovic, Nicolas; Bencze, Gyorgy; Hajdu, Csaba; Horvath, Dezso; Sikler, Ferenc; Veszpremi, Viktor; Vesztergombi, Gyorgy; Zsigmond, Anna Julia; Beni, Noemi; Czellar, Sandor; Karancsi, János; Makovec, Alajos; Molnar, Jozsef; Szillasi, Zoltan; Bartók, Márton; Raics, Peter; Trocsanyi, Zoltan Laszlo; Ujvari, Balazs; Bahinipati, Seema; Choudhury, Somnath; Mal, Prolay; Mandal, Koushik; Nayak, Aruna; Sahoo, Deepak Kumar; Sahoo, Niladribihari; Swain, Sanjay Kumar; Bansal, Sunil; Beri, Suman Bala; Bhatnagar, Vipin; Chawla, Ridhi; Bhawandeep, Bhawandeep; Kalsi, Amandeep Kaur; Kaur, Anterpreet; Kaur, Manjit; Kumar, Ramandeep; Kumari, Priyanka; Mehta, Ankita; Mittal, Monika; Singh, Jasbir; Walia, Genius; Kumar, Ashok; Bhardwaj, Ashutosh; Choudhary, Brajesh C; Garg, Rocky Bala; Keshri, Sumit; Malhotra, Shivali; Naimuddin, Md; Nishu, Nishu; Ranjan, Kirti; Sharma, Ramkrishna; Sharma, Varun; Bhattacharya, Rajarshi; Bhattacharya, Satyaki; Chatterjee, Kalyanmoy; Dey, Sourav; Dutt, Suneel; Dutta, Suchandra; Ghosh, Shamik; Majumdar, Nayana; Modak, Atanu; Mondal, Kuntal; Mukhopadhyay, Supratik; Nandan, Saswati; Purohit, Arnab; Roy, Ashim; Roy, Debarati; Roy Chowdhury, Suvankar; Sarkar, Subir; Sharan, Manoj; Thakur, Shalini; Behera, Prafulla Kumar; Chudasama, Ruchi; Dutta, Dipanwita; Jha, Vishwajeet; Kumar, Vineet; Mohanty, Ajit Kumar; Netrakanti, Pawan Kumar; Pant, Lalit Mohan; Shukla, Prashant; Topkar, Anita; Aziz, Tariq; Dugad, Shashikant; Kole, Gouranga; Mahakud, Bibhuprasad; Mitra, Soureek; Mohanty, Gagan Bihari; Parida, Bibhuti; Sur, Nairit; Sutar, Bajrang; Banerjee, Sudeshna; Bhowmik, Sandeep; Dewanjee, Ram Krishna; Ganguly, Sanmay; Guchait, Monoranjan; Jain, Sandhya; Kumar, Sanjeev; Maity, Manas; Majumder, Gobinda; Mazumdar, Kajari; Sarkar, Tanmay; Wickramage, Nadeesha; Chauhan, Shubhanshu; Dube, Sourabh; Hegde, Vinay; Kapoor, Anshul; Kothekar, Kunal; Pandey, Shubham; Rane, Aditee; Sharma, Seema; Behnamian, Hadi; Chenarani, Shirin; Eskandari Tadavani, Esmaeel; Etesami, Seyed Mohsen; Fahim, Ali; Khakzad, Mohsen; Mohammadi Najafabadi, Mojtaba; Naseri, Mohsen; Paktinat Mehdiabadi, Saeid; Rezaei Hosseinabadi, Ferdos; Safarzadeh, Batool; Zeinali, Maryam; Felcini, Marta; Grunewald, Martin; Abbrescia, Marcello; Calabria, Cesare; Caputo, Claudio; Colaleo, Anna; Creanza, Donato; Cristella, Leonardo; De Filippis, Nicola; De Palma, Mauro; Fiore, Luigi; Iaselli, Giuseppe; Maggi, Giorgio; Maggi, Marcello; Miniello, Giorgia; My, Salvatore; Nuzzo, Salvatore; Pompili, Alexis; Pugliese, Gabriella; Radogna, Raffaella; Ranieri, Antonio; Selvaggi, Giovanna; Silvestris, Lucia; Venditti, Rosamaria; Verwilligen, Piet; Abbiendi, Giovanni; Battilana, Carlo; Bonacorsi, Daniele; Braibant-Giacomelli, Sylvie; Brigliadori, Luca; Campanini, Renato; Capiluppi, Paolo; Castro, Andrea; Cavallo, Francesca Romana; Chhibra, Simranjit Singh; Codispoti, Giuseppe; Cuffiani, Marco; Dallavalle, Gaetano-Marco; Fabbri, Fabrizio; Fanfani, Alessandra; Fasanella, Daniele; Giacomelli, Paolo; Grandi, Claudio; Guiducci, Luigi; Marcellini, Stefano; Masetti, Gianni; Montanari, Alessandro; Navarria, Francesco; Perrotta, Andrea; Rossi, Antonio; Rovelli, Tiziano; Siroli, Gian Piero; Tosi, Nicolò; Albergo, Sebastiano; Costa, Salvatore; Di Mattia, Alessandro; Giordano, Ferdinando; Potenza, Renato; Tricomi, Alessia; Tuve, Cristina; Barbagli, Giuseppe; Ciulli, Vitaliano; Civinini, Carlo; D'Alessandro, Raffaello; Focardi, Ettore; Lenzi, Piergiulio; Meschini, Marco; Paoletti, Simone; Sguazzoni, Giacomo; Viliani, Lorenzo; Benussi, Luigi; Bianco, Stefano; Fabbri, Franco; Piccolo, Davide; Primavera, Federica; Calvelli, Valerio; Ferro, Fabrizio; Lo Vetere, Maurizio; Monge, Maria Roberta; Robutti, Enrico; Tosi, Silvano; Brianza, Luca; Dinardo, Mauro Emanuele; Fiorendi, Sara; Gennai, Simone; Ghezzi, Alessio; Govoni, Pietro; Malberti, Martina; Malvezzi, Sandra; Manzoni, Riccardo Andrea; Menasce, Dario; Moroni, Luigi; Paganoni, Marco; Pedrini, Daniele; Pigazzini, Simone; Ragazzi, Stefano; Tabarelli de Fatis, Tommaso; Buontempo, Salvatore; Cavallo, Nicola; De Nardo, Guglielmo; Di Guida, Salvatore; Esposito, Marco; Fabozzi, Francesco; Fienga, Francesco; Iorio, Alberto Orso Maria; Lanza, Giuseppe; Lista, Luca; Meola, Sabino; Paolucci, Pierluigi; Sciacca, Crisostomo; Thyssen, Filip; Azzi, Patrizia; Bacchetta, Nicola; Benato, Lisa; Bisello, Dario; Boletti, Alessio; Carlin, Roberto; Carvalho Antunes De Oliveira, Alexandra; Checchia, Paolo; Dall'Osso, Martino; De Castro Manzano, Pablo; Dorigo, Tommaso; Dosselli, Umberto; Gasparini, Fabrizio; Gasparini, Ugo; Gozzelino, Andrea; Lacaprara, Stefano; Margoni, Martino; Meneguzzo, Anna Teresa; Pazzini, Jacopo; Pozzobon, Nicola; Ronchese, Paolo; Simonetto, Franco; Torassa, Ezio; Zanetti, Marco; Zotto, Pierluigi; Zumerle, Gianni; Braghieri, Alessandro; Magnani, Alice; Montagna, Paolo; Ratti, Sergio P; Re, Valerio; Riccardi, Cristina; Salvini, Paola; Vai, Ilaria; Vitulo, Paolo; Alunni Solestizi, Luisa; Bilei, Gian Mario; Ciangottini, Diego; Fanò, Livio; Lariccia, Paolo; Leonardi, Roberto; Mantovani, Giancarlo; Menichelli, Mauro; Saha, Anirban; Santocchia, Attilio; Androsov, Konstantin; Azzurri, Paolo; Bagliesi, Giuseppe; Bernardini, Jacopo; Boccali, Tommaso; Castaldi, Rino; Ciocci, Maria Agnese; Dell'Orso, Roberto; Donato, Silvio; Fedi, Giacomo; Giassi, Alessandro; Grippo, Maria Teresa; Ligabue, Franco; Lomtadze, Teimuraz; Martini, Luca; Messineo, Alberto; Palla, Fabrizio; Rizzi, Andrea; Savoy-Navarro, Aurore; Spagnolo, Paolo; Tenchini, Roberto; Tonelli, Guido; Venturi, Andrea; Verdini, Piero Giorgio; Barone, Luciano; Cavallari, Francesca; Cipriani, Marco; Del Re, Daniele; Diemoz, Marcella; Gelli, Simone; Longo, Egidio; Margaroli, Fabrizio; Marzocchi, Badder; Meridiani, Paolo; Organtini, Giovanni; Paramatti, Riccardo; Preiato, Federico; Rahatlou, Shahram; Rovelli, Chiara; Santanastasio, Francesco; Amapane, Nicola; Arcidiacono, Roberta; Argiro, Stefano; Arneodo, Michele; Bartosik, Nazar; Bellan, Riccardo; Biino, Cristina; Cartiglia, Nicolo; Cenna, Francesca; Costa, Marco; Covarelli, Roberto; Degano, Alessandro; Demaria, Natale; Finco, Linda; Kiani, Bilal; Mariotti, Chiara; Maselli, Silvia; Migliore, Ernesto; Monaco, Vincenzo; Monteil, Ennio; Monteno, Marco; Obertino, Maria Margherita; Pacher, Luca; Pastrone, Nadia; Pelliccioni, Mario; Pinna Angioni, Gian Luca; Ravera, Fabio; Romero, Alessandra; Ruspa, Marta; Sacchi, Roberto; Shchelina, Ksenia; Sola, Valentina; Solano, Ada; Staiano, Amedeo; Traczyk, Piotr; Belforte, Stefano; Casarsa, Massimo; Cossutti, Fabio; Della Ricca, Giuseppe; Zanetti, Anna; Kim, Dong Hee; Kim, Gui Nyun; Kim, Min Suk; Lee, Sangeun; Lee, Seh Wook; Oh, Young Do; Sekmen, Sezen; Son, Dong-Chul; Yang, Yu Chul; Lee, Ari; Kim, Hyunchul; Brochero Cifuentes, Javier Andres; Kim, Tae Jeong; Cho, Sungwoong; Choi, Suyong; Go, Yeonju; Gyun, Dooyeon; Ha, Seungkyu; Hong, Byung-Sik; Jo, Youngkwon; Kim, Yongsun; Lee, Byounghoon; Lee, Kisoo; Lee, Kyong Sei; Lee, Songkyo; Lim, Jaehoon; Park, Sung Keun; Roh, Youn; Almond, John; Kim, Junho; Lee, Haneol; Oh, Sung Bin; Radburn-Smith, Benjamin Charles; Seo, Seon-hee; Yang, Unki; Yoo, Hwi Dong; Yu, Geum Bong; Choi, Minkyoo; Kim, Hyunyong; Kim, Ji Hyun; Lee, Jason Sang Hun; Park, Inkyu; Ryu, Geonmo; Ryu, Min Sang; Choi, Young-Il; Goh, Junghwan; Hwang, Chanwook; Lee, Jongseok; Yu, Intae; Dudenas, Vytautas; Juodagalvis, Andrius; Vaitkus, Juozas; Ahmed, Ijaz; Ibrahim, Zainol Abidin; Komaragiri, Jyothsna Rani; Md Ali, Mohd Adli Bin; Mohamad Idris, Faridah; Wan Abdullah, Wan Ahmad Tajuddin; Yusli, Mohd Nizam; Zolkapli, Zukhaimira; Castilla-Valdez, Heriberto; De La Cruz-Burelo, Eduard; Heredia-De La Cruz, Ivan; Hernandez-Almada, Alberto; Lopez-Fernandez, Ricardo; Magaña Villalba, Ricardo; Mejia Guisao, Jhovanny; Sánchez Hernández, Alberto; Carrillo Moreno, Salvador; Oropeza Barrera, Cristina; Vazquez Valencia, Fabiola; Carpinteyro, Severiano; Pedraza, Isabel; Salazar Ibarguen, Humberto Antonio; Uribe Estrada, Cecilia; Morelos Pineda, Antonio; Krofcheck, David; Butler, Philip H; Ahmad, Ashfaq; Ahmad, Muhammad; Hassan, Qamar; Hoorani, Hafeez R; Khan, Wajid Ali; Saddique, Asif; Shah, Mehar Ali; Shoaib, Muhammad; Waqas, Muhammad; Bialkowska, Helena; Bluj, Michal; Boimska, Bożena; Frueboes, Tomasz; Górski, Maciej; Kazana, Malgorzata; Nawrocki, Krzysztof; Romanowska-Rybinska, Katarzyna; Szleper, Michal; Zalewski, Piotr; Bunkowski, Karol; Byszuk, Adrian; Doroba, Krzysztof; Kalinowski, Artur; Konecki, Marcin; Krolikowski, Jan; Misiura, Maciej; Olszewski, Michal; Walczak, Marek; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Calpas, Betty; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Nemallapudi, Mythra Varun; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; Afanasiev, Serguei; Bunin, Pavel; Gavrilenko, Mikhail; Golutvin, Igor; Gorbunov, Ilya; Kamenev, Alexey; Karjavin, Vladimir; Lanev, Alexander; Malakhov, Alexander; Matveev, Viktor; Palichik, Vladimir; Perelygin, Victor; Shmatov, Sergey; Shulha, Siarhei; Skatchkov, Nikolai; Smirnov, Vitaly; Voytishin, Nikolay; Zarubin, Anatoli; Chtchipounov, Leonid; Golovtsov, Victor; Ivanov, Yury; Kim, Victor; Kuznetsova, Ekaterina; Murzin, Victor; Oreshkin, Vadim; Sulimov, Valentin; Vorobyev, Alexey; Andreev, Yuri; Dermenev, Alexander; Gninenko, Sergei; Golubev, Nikolai; Karneyeu, Anton; Kirsanov, Mikhail; Krasnikov, Nikolai; Pashenkov, Anatoli; Tlisov, Danila; Toropin, Alexander; Epshteyn, Vladimir; Gavrilov, Vladimir; Lychkovskaya, Natalia; Popov, Vladimir; Pozdnyakov, Ivan; Safronov, Grigory; Spiridonov, Alexander; Toms, Maria; Vlasov, Evgueni; Zhokin, Alexander; Bylinkin, Alexander; Markin, Oleg; Tarkovskii, Evgenii; Andreev, Vladimir; Azarkin, Maksim; Dremin, Igor; Kirakosyan, Martin; Leonidov, Andrey; Terkulov, Adel; Baskakov, Alexey; Belyaev, Andrey; Boos, Edouard; Ershov, Alexander; Gribushin, Andrey; Kaminskiy, Alexandre; Kodolova, Olga; Korotkikh, Vladimir; Lokhtin, Igor; Miagkov, Igor; Obraztsov, Stepan; Petrushanko, Sergey; Savrin, Viktor; Snigirev, Alexander; Vardanyan, Irina; Blinov, Vladimir; Skovpen, Yuri; Shtol, Dmitry; Azhgirey, Igor; Bayshev, Igor; Bitioukov, Sergei; Elumakhov, Dmitry; Kachanov, Vassili; Kalinin, Alexey; Konstantinov, Dmitri; Krychkine, Victor; Petrov, Vladimir; Ryutin, Roman; Sobol, Andrei; Troshin, Sergey; Tyurin, Nikolay; Uzunian, Andrey; Volkov, Alexey; Adzic, Petar; Cirkovic, Predrag; Devetak, Damir; Dordevic, Milos; Milosevic, Jovan; Rekovic, Vladimir; Alcaraz Maestre, Juan; Barrio Luna, Mar; Calvo, Enrique; Cerrada, Marcos; Chamizo Llatas, Maria; Colino, Nicanor; De La Cruz, Begona; Delgado Peris, Antonio; Escalante Del Valle, Alberto; Fernandez Bedoya, Cristina; Fernández Ramos, Juan Pablo; Flix, Jose; Fouz, Maria Cruz; Garcia-Abia, Pablo; Gonzalez Lopez, Oscar; Goy Lopez, Silvia; Hernandez, Jose M; Josa, Maria Isabel; Navarro De Martino, Eduardo; Pérez-Calero Yzquierdo, Antonio María; Puerta Pelayo, Jesus; Quintario Olmeda, Adrián; Redondo, Ignacio; Romero, Luciano; Senghi Soares, Mara; de Trocóniz, Jorge F; Missiroli, Marino; Moran, Dermot; Cuevas, Javier; Fernandez Menendez, Javier; Gonzalez Caballero, Isidro; González Fernández, Juan Rodrigo; Palencia Cortezon, Enrique; Sanchez Cruz, Sergio; Suárez Andrés, Ignacio; Vizan Garcia, Jesus Manuel; Cabrillo, Iban Jose; Calderon, Alicia; Castiñeiras De Saa, Juan Ramon; Curras, Esteban; Fernandez, Marcos; Garcia-Ferrero, Juan; Gomez, Gervasio; Lopez Virto, Amparo; Marco, Jesus; Martinez Rivero, Celso; Matorras, Francisco; Piedra Gomez, Jonatan; Rodrigo, Teresa; Ruiz-Jimeno, Alberto; Scodellaro, Luca; Trevisani, Nicolò; Vila, Ivan; Vilar Cortabitarte, Rocio; Abbaneo, Duccio; Auffray, Etiennette; Auzinger, Georg; Bachtis, Michail; Baillon, Paul; Ball, Austin; Barney, David; Bloch, Philippe; Bocci, Andrea; Bonato, Alessio; Botta, Cristina; Camporesi, Tiziano; Castello, Roberto; Cepeda, Maria; Cerminara, Gianluca; D'Alfonso, Mariarosaria; D'Enterria, David; Dabrowski, Anne; Daponte, Vincenzo; David Tinoco Mendes, Andre; De Gruttola, Michele; De Roeck, Albert; Di Marco, Emanuele; Dobson, Marc; Dorney, Brian; Du Pree, Tristan; Duggan, Daniel; Dünser, Marc; Dupont, Niels; Elliott-Peisert, Anna; Fartoukh, Stephane; Franzoni, Giovanni; Fulcher, Jonathan; Funk, Wolfgang; Gigi, Dominique; Gill, Karl; Girone, Maria; Glege, Frank; Gulhan, Doga; Gundacker, Stefan; Guthoff, Moritz; Hammer, Josef; Harris, Philip; Hegeman, Jeroen; Innocente, Vincenzo; Janot, Patrick; Kieseler, Jan; Kirschenmann, Henning; Knünz, Valentin; Kornmayer, Andreas; Kortelainen, Matti J; Kousouris, Konstantinos; Krammer, Manfred; Lange, Clemens; Lecoq, Paul; Lourenco, Carlos; Lucchini, Marco Toliman; Malgeri, Luca; Mannelli, Marcello; Martelli, Arabella; Meijers, Frans; Merlin, Jeremie Alexandre; Mersi, Stefano; Meschi, Emilio; Milenovic, Predrag; Moortgat, Filip; Morovic, Srecko; Mulders, Martijn; Neugebauer, Hannes; Orfanelli, Styliani; Orsini, Luciano; Pape, Luc; Perez, Emmanuelle; Peruzzi, Marco; Petrilli, Achille; Petrucciani, Giovanni; Pfeiffer, Andreas; Pierini, Maurizio; Racz, Attila; Reis, Thomas; Rolandi, Gigi; Rovere, Marco; Ruan, Manqi; Sakulin, Hannes; Sauvan, Jean-Baptiste; Schäfer, Christoph; Schwick, Christoph; Seidel, Markus; Sharma, Archana; Silva, Pedro; Sphicas, Paraskevas; Steggemann, Jan; Stoye, Markus; Takahashi, Yuta; Tosi, Mia; Treille, Daniel; Triossi, Andrea; Tsirou, Andromachi; Veckalns, Viesturs; Veres, Gabor Istvan; Verweij, Marta; Wardle, Nicholas; Wöhri, Hermine Katharina; Zagoździńska, Agnieszka; Zeuner, Wolfram Dietrich; Bertl, Willi; Deiters, Konrad; Erdmann, Wolfram; Horisberger, Roland; 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Gary, J William; Ghiasi Shirazi, Seyyed Mohammad Amin; Hanson, Gail; Heilman, Jesse; Jandir, Pawandeep; Kennedy, Elizabeth; Lacroix, Florent; Long, Owen Rosser; Olmedo Negrete, Manuel; Paneva, Mirena Ivova; Shrinivas, Amithabh; Si, Weinan; Wei, Hua; Wimpenny, Stephen; Yates, Brent; Branson, James G; Cerati, Giuseppe Benedetto; Cittolin, Sergio; Derdzinski, Mark; Holzner, André; Klein, Daniel; Krutelyov, Vyacheslav; Letts, James; Macneill, Ian; Olivito, Dominick; Padhi, Sanjay; Pieri, Marco; Sani, Matteo; Sharma, Vivek; Simon, Sean; Tadel, Matevz; Vartak, Adish; Wasserbaech, Steven; Welke, Charles; Wood, John; Würthwein, Frank; Yagil, Avraham; Zevi Della Porta, Giovanni; Amin, Nick; Bhandari, Rohan; Bradmiller-Feld, John; Campagnari, Claudio; Dishaw, Adam; Dutta, Valentina; Franco Sevilla, Manuel; George, Christopher; Golf, Frank; Gouskos, Loukas; Gran, Jason; Heller, Ryan; Incandela, Joe; Mullin, Sam Daniel; Ovcharova, Ana; Qu, Huilin; Richman, Jeffrey; Stuart, David; Suarez, Indara; Yoo, Jaehyeok; 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Bhat, Pushpalatha C; Bolla, Gino; Burkett, Kevin; Butler, Joel Nathan; Cheung, Harry; Chlebana, Frank; Cihangir, Selcuk; Cremonesi, Matteo; Elvira, Victor Daniel; Fisk, Ian; Freeman, Jim; Gottschalk, Erik; Gray, Lindsey; Green, Dan; Grünendahl, Stefan; Gutsche, Oliver; Hare, Daryl; Harris, Robert M; Hasegawa, Satoshi; Hirschauer, James; Hu, Zhen; Jayatilaka, Bodhitha; Jindariani, Sergo; Johnson, Marvin; Joshi, Umesh; Klima, Boaz; Kreis, Benjamin; Lammel, Stephan; Linacre, Jacob; Lincoln, Don; Lipton, Ron; Liu, Tiehui; Lopes De Sá, Rafael; Lykken, Joseph; Maeshima, Kaori; Magini, Nicolo; Marraffino, John Michael; Maruyama, Sho; Mason, David; McBride, Patricia; Merkel, Petra; Mrenna, Stephen; Nahn, Steve; Newman-Holmes, Catherine; O'Dell, Vivian; Pedro, Kevin; Prokofyev, Oleg; Rakness, Gregory; Ristori, Luciano; Sexton-Kennedy, Elizabeth; Soha, Aron; Spalding, William J; Spiegel, Leonard; Stoynev, Stoyan; Strobbe, Nadja; Taylor, Lucas; Tkaczyk, Slawek; Tran, Nhan Viet; Uplegger, Lorenzo; 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Apanasevich, Leonard; Berry, Douglas; Betts, Russell Richard; Bucinskaite, Inga; Cavanaugh, Richard; Evdokimov, Olga; Gauthier, Lucie; Gerber, Cecilia Elena; Hofman, David Jonathan; Jung, Kurt; Kurt, Pelin; O'Brien, Christine; Sandoval Gonzalez, Irving Daniel; Turner, Paul; Varelas, Nikos; Wang, Hui; Wu, Zhenbin; Zakaria, Mohammed; Zhang, Jingyu; Bilki, Burak; Clarida, Warren; Dilsiz, Kamuran; Durgut, Süleyman; Gandrajula, Reddy Pratap; Haytmyradov, Maksat; Khristenko, Viktor; Merlo, Jean-Pierre; Mermerkaya, Hamit; Mestvirishvili, Alexi; Moeller, Anthony; Nachtman, Jane; Ogul, Hasan; Onel, Yasar; Ozok, Ferhat; Penzo, Aldo; Snyder, Christina; Tiras, Emrah; Wetzel, James; Yi, Kai; Anderson, Ian; Blumenfeld, Barry; Cocoros, Alice; Eminizer, Nicholas; Fehling, David; Feng, Lei; Gritsan, Andrei; Maksimovic, Petar; Martin, Christopher; Osherson, Marc; Roskes, Jeffrey; Sarica, Ulascan; Swartz, Morris; Xiao, Meng; Xin, Yongjie; You, Can; Al-bataineh, Ayman; Baringer, Philip; Bean, Alice; Boren, Samuel; 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Hsu, Dylan; Iiyama, Yutaro; Innocenti, Gian Michele; Klute, Markus; Kovalskyi, Dmytro; Krajczar, Krisztian; Lai, Yue Shi; Lee, Yen-Jie; Levin, Andrew; Luckey, Paul David; Maier, Benedikt; Marini, Andrea Carlo; Mcginn, Christopher; Mironov, Camelia; Narayanan, Siddharth; Niu, Xinmei; Paus, Christoph; Roland, Christof; Roland, Gunther; Salfeld-Nebgen, Jakob; Stephans, George; Sumorok, Konstanty; Tatar, Kaya; Varma, Mukund; Velicanu, Dragos; Veverka, Jan; Wang, Jing; Wang, Ta-Wei; Wyslouch, Bolek; Yang, Mingming; Zhukova, Victoria; Benvenuti, Alberto; Chatterjee, Rajdeep Mohan; Evans, Andrew; Finkel, Alexey; Gude, Alexander; Hansen, Peter; Kalafut, Sean; Kao, Shih-Chuan; Kubota, Yuichi; Lesko, Zachary; Mans, Jeremy; Nourbakhsh, Shervin; Ruckstuhl, Nicole; Rusack, Roger; Tambe, Norbert; Turkewitz, Jared; Acosta, John Gabriel; Oliveros, Sandra; Avdeeva, Ekaterina; Bartek, Rachel; Bloom, Kenneth; Claes, Daniel R; Dominguez, Aaron; Fangmeier, Caleb; Gonzalez Suarez, Rebeca; Kamalieddin, Rami; Kravchenko, Ilya; Malta Rodrigues, Alan; Meier, Frank; Monroy, Jose; Siado, Joaquin Emilo; Snow, Gregory R; Stieger, Benjamin; Alyari, Maral; Dolen, James; George, Jimin; Godshalk, Andrew; Harrington, Charles; Iashvili, Ia; Kaisen, Josh; Kharchilava, Avto; Kumar, Ashish; Parker, Ashley; Rappoccio, Salvatore; Roozbahani, Bahareh; Alverson, George; Barberis, Emanuela; Hortiangtham, Apichart; Massironi, Andrea; Morse, David Michael; Nash, David; Orimoto, Toyoko; Teixeira De Lima, Rafael; Trocino, Daniele; Wang, Ren-Jie; Wood, Darien; Bhattacharya, Saptaparna; Charaf, Otman; Hahn, Kristan Allan; Kubik, Andrew; Kumar, Ajay; Mucia, Nicholas; Odell, Nathaniel; Pollack, Brian; Schmitt, Michael Henry; Sung, Kevin; Trovato, Marco; Velasco, Mayda; Dev, Nabarun; Hildreth, Michael; Hurtado Anampa, Kenyi; Jessop, Colin; Karmgard, Daniel John; Kellams, Nathan; Lannon, Kevin; Marinelli, Nancy; Meng, Fanbo; Mueller, Charles; Musienko, Yuri; Planer, Michael; Reinsvold, Allison; Ruchti, Randy; Smith, Geoffrey; Taroni, Silvia; Wayne, Mitchell; Wolf, Matthias; Woodard, Anna; Alimena, Juliette; Antonelli, Louis; Bylsma, Ben; Durkin, Lloyd Stanley; Flowers, Sean; Francis, Brian; Hart, Andrew; Hill, Christopher; Hughes, Richard; Ji, Weifeng; Liu, Bingxuan; Luo, Wuming; Puigh, Darren; Winer, Brian L; Wulsin, Howard Wells; Cooperstein, Stephane; Driga, Olga; Elmer, Peter; Hardenbrook, Joshua; Hebda, Philip; Lange, David; Luo, Jingyu; Marlow, Daniel; Mc Donald, Jeffrey; Medvedeva, Tatiana; Mei, Kelvin; Mooney, Michael; Olsen, James; Palmer, Christopher; Piroué, Pierre; Stickland, David; Svyatkovskiy, Alexey; Tully, Christopher; Zuranski, Andrzej; Malik, Sudhir; Barker, Anthony; Barnes, Virgil E; Folgueras, Santiago; Gutay, Laszlo; Jha, Manoj; Jones, Matthew; Jung, Andreas Werner; Miller, David Harry; Neumeister, Norbert; Schulte, Jan-Frederik; Shi, Xin; Sun, Jian; Wang, Fuqiang; Xie, Wei; Parashar, Neeti; Stupak, John; Adair, Antony; Akgun, Bora; Chen, Zhenyu; Ecklund, Karl Matthew; Geurts, Frank JM; Guilbaud, Maxime; Li, Wei; Michlin, Benjamin; Northup, Michael; Padley, Brian Paul; Redjimi, Radia; Roberts, Jay; Rorie, Jamal; Tu, Zhoudunming; Zabel, James; Betchart, Burton; Bodek, Arie; de Barbaro, Pawel; Demina, Regina; Duh, Yi-ting; Ferbel, Thomas; Galanti, Mario; Garcia-Bellido, Aran; Han, Jiyeon; Hindrichs, Otto; Khukhunaishvili, Aleko; Lo, Kin Ho; Tan, Ping; Verzetti, Mauro; Agapitos, Antonis; Chou, John Paul; Contreras-Campana, Emmanuel; Gershtein, Yuri; Gómez Espinosa, Tirso Alejandro; Halkiadakis, Eva; Heindl, Maximilian; Hidas, Dean; Hughes, Elliot; Kaplan, Steven; Kunnawalkam Elayavalli, Raghav; Kyriacou, Savvas; Lath, Amitabh; Nash, Kevin; Saka, Halil; Salur, Sevil; Schnetzer, Steve; Sheffield, David; Somalwar, Sunil; Stone, Robert; Thomas, Scott; Thomassen, Peter; Walker, Matthew; Delannoy, Andrés G; Foerster, Mark; Heideman, Joseph; Riley, Grant; Rose, Keith; Spanier, Stefan; Thapa, Krishna; Bouhali, Othmane; Celik, Ali; Dalchenko, Mykhailo; De Mattia, Marco; Delgado, Andrea; Dildick, Sven; Eusebi, Ricardo; Gilmore, Jason; Huang, Tao; Juska, Evaldas; Kamon, Teruki; Mueller, Ryan; Pakhotin, Yuriy; Patel, Rishi; Perloff, Alexx; Perniè, Luca; Rathjens, Denis; Rose, Anthony; Safonov, Alexei; Tatarinov, Aysen; Ulmer, Keith; Akchurin, Nural; Cowden, Christopher; Damgov, Jordan; De Guio, Federico; Dragoiu, Cosmin; Dudero, Phillip Russell; Faulkner, James; Gurpinar, Emine; Kunori, Shuichi; Lamichhane, Kamal; Lee, Sung Won; Libeiro, Terence; Peltola, Timo; Undleeb, Sonaina; Volobouev, Igor; Wang, Zhixing; Greene, Senta; Gurrola, Alfredo; Janjam, Ravi; Johns, Willard; Maguire, Charles; Melo, Andrew; Ni, Hong; Sheldon, Paul; Tuo, Shengquan; Velkovska, Julia; Xu, Qiao; Arenton, Michael Wayne; Barria, Patrizia; Cox, Bradley; Goodell, Joseph; Hirosky, Robert; Ledovskoy, Alexander; Li, Hengne; Neu, Christopher; Sinthuprasith, Tutanon; Sun, Xin; Wang, Yanchu; Wolfe, Evan; Xia, Fan; Clarke, Christopher; Harr, Robert; Karchin, Paul Edmund; Sturdy, Jared; Belknap, Donald; Buchanan, James; Caillol, Cécile; Dasu, Sridhara; Dodd, Laura; Duric, Senka; Gomber, Bhawna; Grothe, Monika; Herndon, Matthew; Hervé, Alain; Klabbers, Pamela; Lanaro, Armando; Levine, Aaron; Long, Kenneth; Loveless, Richard; Ojalvo, Isabel; Perry, Thomas; Pierro, Giuseppe Antonio; Polese, Giovanni; Ruggles, Tyler; Savin, Alexander; Smith, Nicholas; Smith, Wesley H; Taylor, Devin; Woods, Nathaniel
2017-03-24
Charge-dependent azimuthal particle correlations with respect to the second-order event plane in pPb and PbPb collisions at a nucleon-nucleon center-of-mass energy of 5.02 TeV have been studied with the CMS experiment at the LHC. The measurement is performed with a three-particle correlation technique, using two particles with the same or opposite charge within the pseudorapidity range $| \\eta | < $ 2.4, and a third particle measured in the hadron forward calorimeters (4.4 $ < | \\eta | < $ 5). The observed differences between the same and opposite sign correlations, as functions of multiplicity and $\\eta$ gap between the two charged particles, are of similar magnitude in pPb and PbPb collisions at the same multiplicities. These results pose a challenge for the interpretation of charge-dependent azimuthal correlations in heavy ion collisions in terms of the chiral magnetic effect.
Wang, X J; Wang, Xiao-Jun; Yan, Mu-Lin
1999-01-01
We study SU(3)$_L\\timesSU(3)_R$ chiral quark model of mesons up to next leading order of $1/N_c$ expansion. Composite vector and axial-vector mesons resonances are introduced via non-linear realization of chiral SU(3) and vector meson dominant. Effects of one-loop graphs of pseudoscalar, vector and axial-vector mesons is calculated systematically and the significant results are obtained. Correction of effective gluon interaction is studied too. The light quark masses are introduced via new mechanism which agree with phenomenology and the requirement of chiral symmetry. Up to powers four of derivatives, chiral effective lagrangian of mesons is derived and evaluated to next leading order of $1/N_c$. Low energy limit of the model is examined. Ten low energy coupling constants $L_i(i=1,2,...,10)$ in ChPT are obtained and agree with ChPT well.
Local chiral potentials and the structure of light nuclei
Piarulli, Maria; Schiavilla, Rocco; Kievsky, Alejandro; Lovato, Alessandro; Marcucci, Laura E; Pieper, Steven C; Viviani, Michele; Wiringa, Robert B
2016-01-01
We present fully local versions of the minimally non-local nucleon-nucleon potentials constructed in a previous paper [M.\\ Piarulli {\\it et al.}, Phys.\\ Rev.\\ C {\\bf 91}, 024003 (2015)], and use them in hypersperical-harmonics and quantum Monte Carlo calculations of ground and excited states of $^3$H, $^3$He, $^4$He, $^6$He, and $^6$Li nuclei. The long-range part of these local potentials includes one- and two-pion exchange contributions without and with $\\Delta$-isobars in the intermediate states up to order $Q^3$ ($Q$ denotes generically the low momentum scale) in the chiral expansion, while the short-range part consists of contact interactions up to order $Q^4$. The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database in two different ranges of laboratory energies, either 0--125 MeV or 0--200 MeV, and to the deuteron binding energy and $nn$ singlet scattering length. Fits to these data are performed for three models characterized by long- and short-range cutof...
Meson Effects on the Chiral Condensate at Finite Density
HUANG Mei; ZHUANG Peng-Fei; ZHAO Wei-Qin
2002-01-01
Meson corrections on the chiral condensate up to next-to-leading order in a 1/Nc expansion at finite densityare investigated in the NJL model with explicit chiral symmetry breaking. Compared with mean-field results, the chiralphase transition is still of the first order while the properties near the critical density for chiral phase transition are foundto change significantly.
The Gross-Neveu model at finite temperature at next to leading order in the 1/N expansion
Blaizot, J P; Wschebor, N
2003-01-01
We present new results on the Gross-Neveu model at finite temperature and at next-to-leading order in the 1/N expansion. In particular, a new expression is obtained for the effective potential which is explicitly invariant under renormalization group transformations. The model is used as a playground to investigate various features of field theory at finite temperature. For example we verify that, as expected from general arguments, the cancellation of ultraviolet divergences takes place at finite temperature without the need for introducing counterterms beyond those of zero-temperature. As well known, the discrete chiral symmetry of the 1+1 dimensional model is spontaneously broken at zero temperature and restored, in leading order, at some temperature T_c; we find that the 1/N approximation breaks down for temperatures below T_c: As the temperature increases, the fluctuations become eventually too large to be treated as corrections, and a Landau pole invalidates the calculation of the effective potential in...
Chiral effective field theory analysis of hadronic parity violation in few-nucleon systems
Viviani, M. [National Inst. of Nuclear Physics (INFN), Pisa (Italy); Baroni, A. [Old Dominion Univ., Norfolk, VA (United States). Dept. of Physics; Girlanda, L. [Univ. of Salento and INFN-Lecce, Lecce (Italy). Dept. of Mathematical and Physics; Kievsky, A. [National Inst. of Nuclear Physics (INFN), Pisa (Italy); Marcucci, L. E. [Univ. of Pisa (Italy); National Inst. of Nuclear Physics (INFN), Pisa (Italy); Schiavilla, R. [Old Dominion Univ., Norfolk, VA (United States). Dept. of Physics; Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)
2014-06-18
Weak interactions between quarks induce a parity-violating (PV) component in the nucleon-nucleon potential, whose effects are currently being studied in a number of experiments involving few-nucleon systems. In the present work, we reconsider the derivation of this PV component within a chiral effective field theory (${\\chi }$EFT) framework. Purpose: The objectives of the present work are twofold. The first is to perform a detailed analysis of the PV nucleon-nucleon potential up to next-to-next-to-leading (N2LO) order in the chiral expansion, in particular, by determining the number of independent low-energy constants (LECs) at N2LO. The second objective is to investigate PV effects in a number of few-nucleon observables, including the $\\vec{p}$-p longitudinal asymmetry, the neutron spin rotation in n-p and n-d scattering, and the longitudinal asymmetry in the ^{3}He( $\\vec{n}$,p)^{3}H charge-exchange reaction. Methods: The ${\\chi }$EFT PV potential includes one-pion-exchange, two-pion-exchange, and contact terms as well as 1/M (M being the nucleon mass) nonstatic corrections. Dimensional regularization is used to renormalize pion loops. The wave functions for the A=2-4 nuclei are obtained by using strong two- and three-body potentials also derived, for consistency, from ${\\chi }$EFT. In the case of the A=3-4 systems, systems, the wave functions are computed by expanding on a hyperspherical harmonics functions basis. Results: We find that the PV potential at N2LO depends on six LECs: the pion-nucleon PV coupling constant h$1\\atop{π}$ and five parameters multiplying contact interactions. An estimate for the range of values of the various LECs is provided by using available experimental data, and these values are used to obtain predictions for the other PV observables. Conclusions: The ${\\chi }$EFT approach provides a very satisfactory framework to analyze PV effects in few-nucleon systems.
Chiral effective field theory analysis of hadronic parity violation in few-nucleon systems
Viviani, M.; Baroni, A.; Girlanda, L.; Kievsky, A.; Marcucci, L. E.; Schiavilla, R.
2014-06-01
Background: Weak interactions between quarks induce a parity-violating (PV) component in the nucleon-nucleon potential, whose effects are currently being studied in a number of experiments involving few-nucleon systems. In the present work, we reconsider the derivation of this PV component within a chiral effective field theory (χEFT) framework. Purpose: The objectives of the present work are twofold. The first is to perform a detailed analysis of the PV nucleon-nucleon potential up to next-to-next-to-leading (N2LO) order in the chiral expansion, in particular, by determining the number of independent low-energy constants (LECs) at N2LO. The second objective is to investigate PV effects in a number of few-nucleon observables, including the p⃗-p longitudinal asymmetry, the neutron spin rotation in n⃗-p and n⃗-d scattering, and the longitudinal asymmetry in the 3He(n⃗,p)3H charge-exchange reaction. Methods: The χEFT PV potential includes one-pion-exchange, two-pion-exchange, and contact terms as well as 1/M (M being the nucleon mass) nonstatic corrections. Dimensional regularization is used to renormalize pion loops. The wave functions for the A =2-4 nuclei are obtained by using strong two- and three-body potentials also derived, for consistency, from χEFT. In the case of the A =3-4 systems, the wave functions are computed by expanding on a hyperspherical harmonics functions basis. Results: We find that the PV potential at N2LO depends on six LECs: the pion-nucleon PV coupling constant hπ1 and five parameters multiplying contact interactions. An estimate for the range of values of the various LECs is provided by using available experimental data, and these values are used to obtain predictions for the other PV observables. Conclusions: The χEFT approach provides a very satisfactory framework to analyze PV effects in few-nucleon systems.
Kojo, Toru; McLerran, Larry; Pisarski, Robert D
2009-01-01
We consider the formation of chiral density waves in Quarkyonic matter, which is a phase where cold, dense quarks experience confining forces. We model confinement following Gribov and Zwanziger, taking the gluon propagator, in Coulomb gauge and momentum space, as 1/(p^2)^2. We assume that the number of colors, N, is large, and that the quark chemical potential, mu, is much larger than renormalization mass scale, Lambda_QCD. To leading order in 1/N and Lambda_QCD, a gauge theory with Nf flavors of massless quarks in 3+1 dimensions naturally reduces to a gauge theory in 1+1 dimensions, with an enlarged flavor symmetry of SU(2Nf). Through an anomalous chiral rotation, in two dimensions a Fermi sea of massless quarks maps directly onto the corresponding theory in vacuum. A chiral condensate forms locally, and varies with the spatial position, z, as . Following Schon and Thies, we term this two dimensional pion condensate a (Quarkyonic) chiral spiral. Massive quarks also exhibit chiral spirals, with the magnitude...
Soffer's inequality and the transversely polarized Drell-Yan process at next-to-leading order
Martin, O; Stratmann, M; Vogelsang, W
1998-01-01
We check numerically if Soffer's inequality for quark distributions is preserved by next-to-leading order QCD evolution. Assuming that the inequality is saturated at a low hadronic scale we estimate the maximal transverse double spin asymmetry for Drell-Yan muon pair production to next-to-leading order accuracy.
Next-to-leading order QCD corrections to five jet production at the LHC
David Badger, Simon; Biedermann, Benedikt; Uwer, Peter;
2014-01-01
We present theoretical predictions for five-jet production in proton-proton collisions at next-to-leading-order accuracy in QCD. Inclusive as well as differential observables are studied for collision energies of 7 and 8 TeV. In general the next-to-leading-order corrections stabilize the theoreti...
Studies of the dilepton emission from nucleon-nucleon interactions
Bacelar, JCS; Fujiwara, M; Shima, T
2002-01-01
real- and virtual-photon emission during interactions between few-nucleon systems have been investigated at KVI with a 190 MeV proton beam. Here I will concentrate the discussion on the results of the virtual-photon emission for the proton-proton system and proton-deuteron capture. Predictions of a
About Hydrotechnical Laboratory, Professor Smorodinsky, and Nucleon-Nucleon Scattering
Ryndin, R. M.
2013-06-01
Yakov Abramovich Smorodinsky... memory brings me back to those far-off days when we first met in March 1952. We saw each other for the first time at the Hydrotechnical Laboratory (GTL) of the Academy of Sciences of the USSR, REFID="9789814436571_0013FN001">, where I obtained a position after graduation from The Physics Department of Leningrad State University. Already a well known professor, Yakov Abramovich (Ya.A.) was only eleven years older than me, a beginning physicist. Today, I would say that we were almost of the same age. We immediately liked each other, and worked closely together for 18 years until I moved back to St. Petersburg, at that time Leningrad, of course. I learned a lot from Ya.A. during those years: his intrinsic desire and ability to share his knowledge was a peculiarity of his talent...
Relativistic Treatments of the Nucleon-Nucleon System
Beachey, David Joseph
The relativistically minimalist Breit equation is used to study the two-nucleon system. Generally, the equation is noncovariant and its realm of applicability is limited. It is not a field-theoretical equation but, at low energy, it was thought to be a promising candidate to explore the scheme of repulsive vector and attractive scalar interactions as the dominant ingredient of the two -nucleon interaction. In the ^1S_0 singlet case, the equation does indeed seem viable. Dynamically sound interactions and a reasonable fit of the scattering data arise. In a specific application, the discrepancy between the ^1S_0 isovector scattering lengths of the p-p and n -n interactions is explored. This novel charge -symmetry-breaking (CSB) mechanism enlarges the discrepancy between the two lengths, implying a still larger correction is required by other documented (CSB) mechanisms. An all-encompassing model of the ^3S _1-^3D_1 state is, on the other hand, not achieved. Models which best fit the experimental deuteron and elastic scattering data, are unphysical. The vector coupling is driven strongly negative and a dominant interference mechanism arises involving the entirely phenomenological short range OPEP. It was hoped that this parametrized short range OPEP would remain benign while the scalar/vector interference scheme took a lead role. Instead the constraint of avoiding Klein paradox difficulties defeats this picture and achieves the short-range repulsion in the N-N force by ramping up the phenomenological OPEP. It is finally argued that the Breit framework almost certainly does not lend itself to an adequate description of the N-N system. It does, however, point to novel relativistic elements which may ultimately resolve celebrated outstanding problems such as the a_ {t}-r_{m} discrepancy. The triplet scattering length a_ {t} and deuteron matter-radius r _{m} are tightly correlated and resistant to simultaneous fitting in conventional models. The p-wave amplitudes of the lower components of a relativistic framework offer a potential means of resolution.
Studies of the dilepton emission from nucleon-nucleon interactions
Bacelar, JCS; Fujiwara, M; Shima, T
2002-01-01
real- and virtual-photon emission during interactions between few-nucleon systems have been investigated at KVI with a 190 MeV proton beam. Here I will concentrate the discussion on the results of the virtual-photon emission for the proton-proton system and proton-deuteron capture. Predictions of a
Hard probes of short-range nucleon-nucleon correlations
J. Arrington, D. W. Higinbotham, G. Rosner, M. Sargsian
2012-10-01
The strong interaction of nucleons at short distances leads to a high-momentum component to the nuclear wave function, associated with short-range correlations between nucleons. These short-range, high-momentum structures in nuclei are one of the least well understood aspects of nuclear matter, relating to strength outside of the typical mean-field approaches to calculating the structure of nuclei. While it is difficult to study these short-range components, significant progress has been made over the last decade in determining how to cleanly isolate short-range correlations in nuclei. We have moved from asking if such structures exist, to mapping out their strength in nuclei and studying their microscopic structure. A combination of several different measurements, made possible by high-luminosity and high-energy accelerators, coupled with an improved understanding of the reaction mechanism issues involved in studying these structures, has led to significant progress, and provided significant new information on the nature of these small, highly-excited structures in nuclei. We review the general issues related to short-range correlations, survey recent experiments aimed at probing these short-range structures, and lay out future possibilities to further these studies.
Nucleon-nucleon scattering to 800 MeV
Spinka, H.
1984-01-01
Recent data on spin dependent total cross sections and elastic scattering spin observables measured at the meson factories are summarized. Model independent amplitude determinations and phase shift analyses of these data are discussed. The importance of these results for the existence of dibaryons is mentioned. 55 references.
Chiral-scale effective theory including a dilatonic meson
Li, Yan-Ling; Rho, Mannque
2016-01-01
A scale-invariant chiral effective Lagrangian is constructed for octet pions and a dilaton figuring as Nambu-Goldstone bosons with vector mesons incorporated as hidden gauge fields. The Lagrangian is built to the next-to-leading order in chiral-scale counting without baryon fields and then to leading order including baryons. The resulting theory is hidden scale-symmetric and local symmetric. We also discuss some possible applications of the present Lagrangian.
Barik, N.; Mishra, R. N.; Mohanty, D. K.; Panda, P. K.; Frederico, T.
2013-07-01
We have calculated the properties of nuclear matter in a self-consistent manner with a quark-meson coupling mechanism incorporating the structure of nucleons in vacuum through a relativistic potential model; where the dominant confining interaction for the free independent quarks inside a nucleon is represented by a phenomenologically average potential in equally mixed scalar-vector harmonic form. Corrections due to spurious center of mass motion as well as those due to other residual interactions, such as the one gluon exchange at short distances and quark-pion coupling arising out of chiral symmetry restoration, have been considered in a perturbative manner to obtain the nucleon mass in vacuum. The nucleon-nucleon interaction in nuclear matter is then realized by introducing additional quark couplings to σ and ω mesons through mean field approximations. The relevant parameters of the interaction are obtained self-consistently while realizing the saturation properties such as the binding energy, pressure, and compressibility of the nuclear matter. We also discuss some implications of chiral symmetry in nuclear matter along with the nucleon and nuclear σ term and the sensitivity of nuclear matter binding energy with variations in the light quark mass.
Density-dependent effective baryon-baryon interaction from chiral three-baryon forces
Petschauer, Stefan; Kaiser, Norbert; Meißner, Ulf-G; Weise, Wolfram
2016-01-01
A density-dependent effective potential for the baryon-baryon interaction in the presence of the (hyper)nuclear medium is constructed, based on the leading (irreducible) three-baryon forces derived within SU(3) chiral effective field theory. We evaluate the contributions from three classes: contact terms, one-pion exchange and two-pion exchange. In the strangeness-zero sector we recover the known result for the in-medium nucleon-nucleon interaction. Explicit expressions for the Lambda-nucleon in-medium potential in (asymmetric) nuclear matter are presented. Our results are suitable for implementation into calculations of (hyper)nuclear matter. In order to estimate the low-energy constants of the leading three-baryon forces we introduce the decuplet baryons as explicit degrees of freedom and construct the relevant terms in the minimal non-relativistic Lagrangian. With these, the constants are estimated through decuplet saturation. Utilizing this approximation we provide numerical results for the effect of the ...
Density-dependent effective baryon-baryon interaction from chiral three-baryon forces
Petschauer, Stefan; Haidenbauer, Johann; Kaiser, Norbert; Meißner, Ulf-G.; Weise, Wolfram
2017-01-01
A density-dependent effective potential for the baryon-baryon interaction in the presence of the (hyper)nuclear medium is constructed, based on the leading (irreducible) three-baryon forces derived within SU(3) chiral effective field theory. We evaluate the contributions from three classes: contact terms, one-pion exchange and two-pion exchange. In the strangeness-zero sector we recover the known result for the in-medium nucleon-nucleon interaction. Explicit expressions for the ΛN in-medium potential in (asymmetric) nuclear matter are presented. Our results are suitable for implementation into calculations of (hyper)nuclear matter. In order to estimate the low-energy constants of the leading three-baryon forces we introduce the decuplet baryons as explicit degrees of freedom and construct the relevant terms in the minimal non-relativistic Lagrangian. With these, the constants are estimated through decuplet saturation. Utilizing this approximation we provide numerical results for the effect of the three-body force in symmetric nuclear matter and pure neutron matter on the ΛN interaction. A moderate repulsion that increases with density is found in comparison to the free ΛN interaction.
The nonstrange dibaryon and hidden-color effect in a chiral quark model
Dai, L.R.; Zhang, Y.N.; Sun, Y.L.; Shao, S.J. [Liaoning Normal University, Department of Physics, Dalian (China)
2016-09-15
The exotic nonstrange ΔΔ dibaryon with I(J{sup P}) = 0(3{sup +}) has been confirmed by the experimental data reported by WASA-at-COSY Collaboration, and the result is consistent with our theoretical prediction in the chiral SU(3) quark model and extended chiral SU(3) quark model, showing that the effect from hidden-color channel (CC) is important. In the present work, we further investigate another exotic nonstrange ΔΔ dibaryon with I(J{sup P}) = 3(0{sup +}) in the chiral SU(3) quark model that describes the energies of baryon ground states and the nucleon-nucleon (NN) scattering data satisfactorily. We perform a dynamical coupled-channel study of the ΔΔ-CC system with I(J{sup P}) = 3(0{sup +}) within the framework of resonating group method (RGM). We find that the binding energy of I(J{sup P}) = 3(0{sup +}) state is about 22.3 MeV and a root-mean-square radius (RMS) of 1.03 fm in single-channel calculation. Then we extend the model to include the CC channel to further study the I(J{sup P}) = 3(0{sup +}) state and find that the binding energy is about 31.3 MeV and RMS is 0.97 fm in coupled-channel calculation. We can see that the CC channel coupling has a relatively large effect on this state. The color screening effect is further considered and we find that the bound state property will not change much. It is shown that the binding energy of this state is stably ranged around several tens of MeV; it means that its mass is always lower than the threshold of the ΔΔ channel and higher than the mass of NΔπ. (orig.)
The nonstrange dibaryon and hidden-color effect in a chiral quark model
Dai, L. R.; Zhang, Y. N.; Sun, Y. L.; Shao, S. J.
2016-09-01
The exotic nonstrange ΔΔ dibaryon with I(JP) = 0(3+) has been confirmed by the experimental data reported by WASA-at-COSY Collaboration, and the result is consistent with our theoretical prediction in the chiral SU(3) quark model and extended chiral SU(3) quark model, showing that the effect from hidden-color channel ( CC is important. In the present work, we further investigate another exotic nonstrange ΔΔ dibaryon with I(JP) = 3(0+) in the chiral SU(3) quark model that describes the energies of baryon ground states and the nucleon-nucleon (NN) scattering data satisfactorily. We perform a dynamical coupled-channel study of the ΔΔ - CC system with I(JP) = 3(0+) within the framework of resonating group method (RGM). We find that the binding energy of I(JP) = 3(0+) state is about 22.3 MeV and a root-mean-square radius (RMS) of 1.03 fm in single-channel calculation. Then we extend the model to include the CC channel to further study the I(JP) = 3(0+) state and find that the binding energy is about 31.3 MeV and RMS is 0.97 fm in coupled-channel calculation. We can see that the CC channel coupling has a relatively large effect on this state. The color screening effect is further considered and we find that the bound state property will not change much. It is shown that the binding energy of this state is stably ranged around several tens of MeV; it means that its mass is always lower than the threshold of the ΔΔ channel and higher than the mass of NΔπ.
Staggered chiral random matrix theory
Osborn, James C
2010-01-01
We present a random matrix theory (RMT) for the staggered lattice QCD Dirac operator. The staggered RMT is equivalent to the zero-momentum limit of the staggered chiral Lagrangian and includes all taste breaking terms at their leading order. This is an extension of previous work which only included some of the taste breaking terms. We will also present some results for the taste breaking contributions to the partition function and the Dirac eigenvalues.
Chiral behavior of light meson form factors in 2+1 flavor QCD with exact chiral symmetry
Kaneko, T; Cossu, G; Feng, X; Fukaya, H; Hashimoto, S; Noaki, J; Onogi, T
2016-01-01
We present a study of chiral behavior of light meson form factors in QCD with three flavors of overlap quarks. Gauge ensembles are generated at single lattice spacing 0.12 fm with pion masses down to 300 MeV. The pion and kaon electromagnetic form factors and the kaon semileptonic form factors are precisely calculated using the all-to-all quark propagator. We discuss their chiral behavior using the next-to-next-to-leading order chiral perturbation theory.
Fully Differential Vector-Boson-Fusion Higgs Production at Next-to-Next-to-Leading Order.
Cacciari, Matteo; Dreyer, Frédéric A; Karlberg, Alexander; Salam, Gavin P; Zanderighi, Giulia
2015-08-21
We calculate the fully differential next-to-next-to-leading-order (NNLO) corrections to vector-boson fusion (VBF) Higgs boson production at proton colliders, in the limit in which there is no cross talk between the hadronic systems associated with the two protons. We achieve this using a new "projection-to-Born" method that combines an inclusive NNLO calculation in the structure-function approach and a suitably factorized next-to-leading-order VBF Higgs plus three-jet calculation, using appropriate Higgs plus two-parton counterevents. An earlier calculation of the fully inclusive cross section had found small NNLO corrections, at the 1% level. In contrast, the cross section after typical experimental VBF cuts receives NNLO contributions of about (5-6)%, while differential distributions show corrections of up to (10-12)% for some standard observables. The corrections are often outside the next-to-leading-order scale-uncertainty band.
Triton charge radius to next-to-next-to-leading order in pionless effective field theory
Vanasse, Jared
2017-02-01
The triton point charge radius is calculated to next-to-next-to-leading order (NNLO) in pionless effective field theory ( EFT (π / )) , yielding a prediction of 1.14 ±0.19 fm (leading order), 1.59 ±0.08 fm (next-to leading order), and 1.62 ±0.03 fm (NNLO) in agreement with the current experimental extraction of 1.5978 ±0.040 fm [Angeli and Marinova, At. Data Nucl. Data Tables 99, 69 (2013)], 10.1016/j.adt.2011.12.006. The error at NNLO is due to cutoff variation (˜1 % ) within a reasonable range of calculated cutoffs and from a EFT (π / ) error estimate (˜1.5 % ). In addition new techniques are introduced to add perturbative corrections to bound- and scattering state calculations for short-range effective field theories, but with a focus on their use in EFT (π / ) .
Chaos in two black holes with next-to-leading order spin-spin interactions
Huang, Guoqing; Ni, Xiaoting; Wu, Xin [Nanchang University, Department of Physics, Nanchang (China)
2014-08-15
We take into account the dynamics of a complete third post-Newtonian conservative Hamiltonian of two spinning black holes, where the orbital part arrives at the third post-Newtonian precision level and the spin-spin part with the spin-orbit part includes the leading-order and next-to-leading-order contributions. It is shown through numerical simulations that the next-to-leading-order spin-spin couplings play an important role in chaos. A dynamical sensitivity to the variation of single parameter is also investigated in some cases. In particular, there are a number of observable orbits whose initial radii are large enough and which are chaotic before coalescence. (orig.)
Ormand, W. E.; Brown, B. A.; Hjorth-Jensen, M.
2017-08-01
We present calculations for the c coefficients of the isobaric mass multiplet equation for nuclei from A =42 to A =54 based on input from three realistic nucleon-nucleon interactions. We demonstrate that there is a clear dependence on the short-range charge-symmetry-breaking (CSB) part of the strong interaction and that there is significant disagreement in the CSB part between the commonly used CD-Bonn, chiral effective field theory at next-to-next-to-next-to-leading-order, and Argonne V18 nucleon-nucleon interactions. In addition, we show that all three interactions give a CSB contribution to the c coefficient that is too large when compared to experiment.
Leading- and next-to-leading-order lateral Casimir force on corrugated surfaces
Cavero-Pelaez, Ines; Parashar, Prachi; Shajesh, K V
2008-01-01
We derive explicit analytic expressions for the lateral force for two different configurations with corrugations, parallel plates and concentric cylinders. By making use of the multiple scattering formalism, we calculate the force for a scalar field under the influence of a delta-function potential that has sinusoidal dependence in one direction simulating the corrugations. By making a perturbative expansion in the amplitude of the corrugation we find the leading order for the corrugated concentric cylinders and the next-to-leading order for the corrugated parallel plates.
Fragmentation Functions at Next-to-Next-to-Leading Order Accuracy
Anderle, Daniele P; Stratmann, Marco
2015-01-01
We present a first analysis of parton-to-pion fragmentation functions at next-to-next-to-leading order accuracy in QCD based on single-inclusive pion production in electron-positron annihilation. Special emphasis is put on the technical details necessary to perform the QCD scale evolution and cross section calculation in Mellin moment space. We demonstrate how the description of the data and the theoretical uncertainties are improved when next-to-next-to-leading order QCD corrections are included.
Nuclear and partonic dynamics in the EMC effect at Next-to-Next-to-Leading order
Tehrani, S Atashbar
2014-01-01
We study in details the parameterizations of the nuclear parton distributions at the next-to-next-to-leading order (NNLO) of $\\alpha_s$. In low $x$ and $Q_0^2$, we observe negative gluon distribution at this order which signals the saturation condition or the quark-gluon plasma condition. Our study also shows the gluon distribution at (NNLO) is less than next-to-leading order (NLO) of $\\alpha_s$, and the sea quark distribution at (NNLO) is larger than (NLO).
Next-to-Leading-Order Monte Carlo Simulation of Diphoton Production in Hadronic Collisions
D'Errico, Luca
2011-01-01
We present a method, based on the positive weight next-to-leading-order matching formalism (POWHEG), to simulate photon production processes at next-to-leading-order (NLO). This technique is applied to the simulation of diphoton production in hadron-hadron collisions. The algorithm consistently combines the parton shower and NLO calculation, producing only positive weight events. The simulation includes both the photon fragmentation contribution and a full implementation of the truncated shower required to correctly describe soft emissions in an angular-ordered parton shower.
Hadronic contribution to the muon anomalous magnetic moment to next-to-next-to-leading order
Kurz, Alexander [Institut für Theoretische Teilchenphysik, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe (Germany); Deutsches Elektronen Synchrotron (DESY), 15738 Zeuthen (Germany); Liu, Tao [Institut für Theoretische Teilchenphysik, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe (Germany); Marquard, Peter [Deutsches Elektronen Synchrotron (DESY), 15738 Zeuthen (Germany); Steinhauser, Matthias [Institut für Theoretische Teilchenphysik, Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe (Germany)
2014-06-27
We compute the next-to-next-to-leading order hadronic contribution to the muon anomalous magnetic moment originating from the photon vacuum polarization. The corresponding three-loop kernel functions are calculated using asymptotic expansion techniques which lead to analytic expressions. Our final result, a{sub μ}{sup had,NNLO}=1.24±0.01×10{sup −10}, has the same order of magnitude as the current uncertainty of the leading order hadronic contribution and should thus be included in future analyses.
Hadronic contribution to the muon anomalous magnetic moment to next-to-next-to-leading order
Kurz, Alexander; Marquard, Peter; Steinhauser, Matthias
2014-01-01
We compute the next-to-next-to-leading order hadronic contribution to the muon anomalous magnetic moment originating from the photon vacuum polarization. The corresponding three-loop kernel functions are calculated using asymptotic expansion techniques which lead to analytic expressions. Our final result, $a_\\mu^{\\rm had,NNLO} = 1.24 \\pm 0.01 \\times 10^{-10}$, has the same order of magnitude as the current uncertainty of the leading order hadronic contribution and should thus be included in future analyses.
Hadronic contribution to the muon anomalous magnetic moment to next-to-next-to-leading order
Kurz, Alexander [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Inst. fuer Theoretische Teilchenphysik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Liu, Tao; Steinhauser, Matthias [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Inst. fuer Theoretische Teilchenphysik; Marquard, Peter [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)
2014-03-15
We compute the next-to-next-to-leading order hadronic contribution to the muon anomalous magnetic moment originating from the photon vacuum polarization. The corresponding three-loop kernel functions are calculated using asymptotic expansion techniques which lead to analytic expressions. Our final result, a{sup had,NNLO}{sub μ} = 1.24 ± 0.01 x 10{sup -10}, has the same order of magnitude as the current uncertainty of the leading order hadronic contribution and should thus be included in future analyses.
Next-to-leading order SUSY-QCD calculation of associated production of gauginos and gluinos
Berger, Edmond L.; Tait, T.M.P. [Argonne National Laboratory, High Energy Physics Division, Argonne, IL (United States); Klasen, M. [Universitaet Hamburg, II. Institut fuer Theoretische Physik, Hamburg (Germany)
2001-07-01
Results are presented of a next-to-leading order calculation in perturbative QCD of the production of charginos and neutralinos in association with gluinos at hadron colliders. Predictions for cross sections are shown at the energies of the Fermilab Tevatron and CERN Large Hadron Collider for a typical supergravity (SUGRA) model of the sparticle mass spectrum and for a light gluino model. (author)
Inoue, Yoshihisa
2004-01-01
Direct Asymmetric Photochemistry with Circularly Polarized Light, H. RauCoherent Laser Control of the Handedness of Chiral Molecules, P. Brumer and M. ShapiroMagnetochiral Anisotropy in Asymmetric Photochemistry, G.L.J.A.RikkenEnantiodifferentiating Photosensitized Reactions, Y. InoueDiastereodifferentiating Photoreactions, N. Hoffmann and J.-P. PeteChirality in Photochromism, Y. Yokoyama and M. SaitoChiral Photochemistry with Transition Metal Complexes, S. Sakaki and T. HamadaTemplate-Induced Enantioselective Photochemical Reactions in S
Beilinson, Alexander
2004-01-01
Chiral algebras form the primary algebraic structure of modern conformal field theory. Each chiral algebra lives on an algebraic curve, and in the special case where this curve is the affine line, chiral algebras invariant under translations are the same as well-known and widely used vertex algebras. The exposition of this book covers the following topics: the "classical" counterpart of the theory, which is an algebraic theory of non-linear differential equations and their symmetries; the local aspects of the theory of chiral algebras, including the study of some basic examples, such as the ch
Top-quark decay at next-to-next-to-leading order in QCD.
Gao, Jun; Li, Chong Sheng; Zhu, Hua Xing
2013-01-25
We present the complete calculation of the top-quark decay width at next-to-next-to-leading order in QCD, including next-to-leading electroweak corrections as well as finite bottom quark mass and W boson width effects. In particular, we also show the first results of the fully differential decay rates for the top-quark semileptonic decay t → W(+)(l(+)ν)b at next-to-next-to-leading order in QCD. Our method is based on the understanding of the invariant mass distribution of the final-state jet in the singular limit from effective field theory. Our result can be used to study arbitrary infrared-safe observables of top-quark decay with the highest perturbative accuracy.
W+ W- production at hadron colliders in next to next to leading order QCD.
Gehrmann, T; Grazzini, M; Kallweit, S; Maierhöfer, P; von Manteuffel, A; Pozzorini, S; Rathlev, D; Tancredi, L
2014-11-21
Charged gauge boson pair production at the Large Hadron Collider allows detailed probes of the fundamental structure of electroweak interactions. We present precise theoretical predictions for on-shell W+ W- production that include, for the first time, QCD effects up to next to next to leading order in perturbation theory. As compared to next to leading order, the inclusive W+ W- cross section is enhanced by 9% at 7 TeV and 12% at 14 TeV. The residual perturbative uncertainty is at the 3% level. The severe contamination of the W+ W- cross section due to top-quark resonances is discussed in detail. Comparing different definitions of top-free W+ W- production in the four and five flavor number schemes, we demonstrate that top-quark resonances can be separated from the inclusive W+ W- cross section without a significant loss of theoretical precision.
Abramov, Rafail V.
2017-03-01
The classical fluctuation-dissipation theorem predicts the average response of a dynamical system to an external deterministic perturbation via time-lagged statistical correlation functions of the corresponding unperturbed system. In this work we develop a fluctuation-response theory and test a computational framework for the leading order response of statistical averages of a deterministic or stochastic dynamical system to an external stochastic perturbation. In the case of a stochastic unperturbed dynamical system, we compute the leading order fluctuation-response formulas for two different cases: when the existing stochastic term is perturbed, and when a new, statistically independent, stochastic perturbation is introduced. We numerically investigate the effectiveness of the new response formulas for an appropriately rescaled Lorenz 96 system, in both the deterministic and stochastic unperturbed dynamical regimes.
The Standard Model Effective Field Theory and Next to Leading Order
Passarino, Giampiero
2016-01-01
We review the status of calculations in the Standard Model Effective Field Theory (SMEFT) beyond leading order (LO). Improving the SMEFT beyond LO allows theoretical errors to be characterized and reduced when considering SMEFT interpretations of the data, which is essential considering the improving experimental precision at LHC. Next to leading order results also allow a more consistent analysis of measurements with different effective scales in the SMEFT. Going beyond LO is clearly important in the event that deviations from the SM are large enough that experimental indications of physics beyond the SM emerge. We discuss a consistent and well defined approach to LO in the SMEFT, so that the improvement to NLO is straightforward. We discuss the basic issues involved in improving calculations to NLO in the SMEFT, and review the advances in this direction that have been achieved to date.
Single-Spin Asymmetries in W Boson Production at Next-to-Leading Order
Ringer, Felix
2015-01-01
We present an analytic next-to-leading order QCD calculation of the partonic cross sections for single-inclusive lepton production in hadronic collisions, when the lepton originates from the decay of an intermediate electroweak boson and is produced at high transverse momentum. In particular, we consider the case of incoming longitudinally polarized protons for which parity-violating single-spin asymmetries arise that are exploited in the $W$ boson program at RHIC to constrain the proton's helicity parton distributions. Our calculation enables a very fast and efficient numerical computation of the relevant spin asymmetries at RHIC, which is an important ingredient for the inclusion of RHIC data in a global analysis of nucleon helicity structure. We confirm the validity of our calculation by comparing with an existing code that treats the next-to-leading order cross sections entirely numerically by Monte-Carlo integration techniques. We also provide new comparisons of the present RHIC data with results for som...
Three-Parton Contributions to B --> M_1 M_2 Annihilation at Leading Order
Arnesen, C M; Stewart, I W; Arnesen, Christian M.; Rothstein, Ira Z.; Stewart, Iain W.
2006-01-01
We compute annihilation amplitudes for charmless B decays that are proportional to the three-parton twist-3 light meson distribution amplitude phi_{3M}(x1,x2) with an active gluon. Due to an enhancement from a quark propagator at the scale p^2 ~ mb\\Lambda_QCD these terms occur at the same parametric order in alpha_s(mb) and 1/mb as the known leading order annihilation involving fB and twist-2 meson distributions. With our calculation the leading order annihilation amplitude is now complete. At lowest order in alpha_s the amplitudes are real and only O_{5-8} contribute. Using simple models we find that the three-parton and two-parton terms are of comparable size.
Minijet initial state of heavy-ion collisions from next-to-leading order perturbative QCD
Paatelainen, Risto
2014-01-01
The aim of this thesis is to calculate field-theoretically as rigorously as possible the initial state of partonic matter produced in ultrarelativistic heavy-ion collisions at CERN-LHC and BNL-RHIC colliders. The computed minijet initial conditions are then used in the initialization of the relativistic hydrodynamical modeling of these collisions. In the theoretical introduction part the computation of parton production cross section at next-to-leading order (NLO) perturbative QCD (pQCD) is discussed. Furthermore, the full analytical calculation for the squared quark-quark scattering matrix element including the systematic ultraviolet renormalization is presented. Finally, the subtraction method allowing for the cancellation of the infrared and collinear singularities in the partonic QCD cross section at NLO is discussed. In the more phenomenological part of the thesis the original EKRT model, which combines collinearly factorized leading-order pQCD minijet production with gluon saturation, is introduced. Nex...
Spin Polarized Photons from Axially Charged Plasma at Weak Coupling: Complete Leading Order
Mamo, Kiminad A
2015-01-01
In the presence of (approximately conserved) axial charge in the QCD plasma at finite temperature, the emitted photons are spin-aligned, which is a unique P- and CP-odd signature of axial charge in the photon emission observables. We compute this "P-odd photon emission rate" in weak coupling regime at high temperature limit to complete leading order in the QCD coupling constant: the leading log as well as the constant under the log. As in the P-even total emission rate in the literature, the computation of P-odd emission rate at leading order consists of three parts: 1) Compton and Pair Annihilation processes with hard momentum exchange, 2) soft t- and u-channel contributions with Hard Thermal Loop re-summation, 3) Landau-Pomeranchuk-Migdal (LPM) re-summation of collinear Bremstrahlung and Pair Annihilation. We present analytical and numerical evaluations of these contributions to our P-odd photon emission rate observable.
The Gluon-Induced Mueller-Tang Jet Impact Factor at Next-to-Leading Order
Hentschinski, Martin; Murdaca, Beatrice; Vera, Agustín Sabio
2014-01-01
We complete the computation of the Mueller-Tang jet impact factor at next-to-leading order (NLO) initiated in arXiv:1406.5625 and presented in arXiv:1404.2937 by computing the real corrections associated to gluons in the initial state making use of Lipatov's effective action. NLO corrections for this effective vertex are an important ingredient for a reliable description of large rapidity gap phenomenology within the BFKL approach.
Rapidity evolution of Wilson lines at the next-to-leading order
Balitsky, Ian [JLAB, Old Dominion U.; Chirilli, Giovanni [LBL
2013-12-01
At high energies particles move very fast so the proper degrees of freedom for the fast gluons moving along the straight lines are Wilson-line operators - infinite gauge factors ordered along the line. In the framework of operator expansion in Wilson lines the energy dependence of the amplitudes is determined by the rapidity evolution of Wilson lines. We present the next-to-leading order hierarchy of the evolution equations for Wilson-line operators.
Kallin, Catherine; Berlinsky, John
2016-05-01
Chiral superconductivity is a striking quantum phenomenon in which an unconventional superconductor spontaneously develops an angular momentum and lowers its free energy by eliminating nodes in the gap. It is a topologically non-trivial state and, as such, exhibits distinctive topological modes at surfaces and defects. In this paper we discuss the current theory and experimental results on chiral superconductors, focusing on two of the best-studied systems, Sr2RuO4, which is thought to be a chiral triplet p-wave superconductor, and UPt3, which has two low-temperature superconducting phases (in zero magnetic field), the lower of which is believed to be chiral triplet f-wave. Other systems that may exhibit chiral superconductivity are also discussed. Key signatures of chiral superconductivity are surface currents and chiral Majorana modes, Majorana states in vortex cores, and the possibility of half-flux quantum vortices in the case of triplet pairing. Experimental evidence for chiral superconductivity from μSR, NMR, strain, polar Kerr effect and Josephson tunneling experiments are discussed.
Leading-order hadronic contributions to the lepton anomalous magnetic moments from the lattice
Burger Florian
2016-01-01
Full Text Available The hadronic leading-order (hlo contribution to the lepton anomalous magnetic moments alhlo of the Standard Model leptons still accounts for the dominant source of the uncertainty of the Standard Model estimates. We present the results of an investigation of the hadronic leading order anomalous magnetic moments of the electron, muon and tau lepton from first principles in twisted mass lattice QCD. With lattice data for multiple pion masses in the range 230MeV ≲ mPS ≲ 490 MeV, multiple lattice volumes and three lattice spacings we perform the extrapolation to the continuum and to the physical pion mass and check for all systematic uncertainties in the lattice calculation. As a result we calculate alhlo for the three Standard Model leptons with controlled statistical and systematic error in agreement with phenomenological determinations using dispersion relations and experimental data. In addition, we also give a first estimate of the hadronic leading order anomalous magnetic moments from simulations directly at the physical value of the pion mass.
Gelis, François; Laidet, Julien
2013-02-01
In F. Gelis et al. [Phys. Rev. D 78, 054019 (2008).PRVDAQ1550-7998], we have analyzed the leading logarithms of energy that appear in the inclusive spectrum of gluons produced in heavy ion collisions, calculated in the color glass condensate framework. The main result of this paper was that these logarithms are intrinsic properties of the colliding projectiles, and that they can be resummed by letting the distributions of color sources in the nuclei evolve according to the Jalilian-Marian-Iancu-McLerran-Weigert-Leonidov-Kovner equation. An essential step in the proof of this factorization result is the calculation of the gluon spectrum at next-to-leading order (NLO), and in particular a functional relationship that expresses the NLO correction as the action of a certain operator on the leading order spectrum. In this paper, we show that this type of relation between spectra at leading order and NLO is not specific to the production of gluons, but that it is in fact generic for inclusive spectra in heavy ion collisions. To illustrate this, we compute up to NLO the inclusive spectrum of some hypothetical scalar fields, either color neutral or colored, that couple to gluons.
Next-to-Leading Order Predictions for W + 3-Jet Distributions at Hadron Colliders
Berger, C.F.; /MIT, LNS; Bern, Z.; /UCLA; Dixon, L.J.; /SLAC; Febres Cordero, F.; /UCLA; Forde, D.; Gleisberg, T.; /SLAC; Ita, H.; /UCLA; Kosower, D.A.; /Saclay, SPhT; Maitre, D.; /Durham U.
2009-12-09
We present next-to-leading order QCD predictions for a variety of distributions in W + 3-jet production at both the Tevatron and the Large Hadron Collider. We include all subprocesses and incorporate the decay of the W boson into leptons. Our results are in excellent agreement with existing Tevatron data and provide the first quantitatively precise next-to-leading order predictions for the LHC. We include all terms in an expansion in the number of colors, confirming that the specific leading-color approximation used in our previous study is accurate to within three percent. The dependence of the cross section on renormalization and factorization scales is reduced significantly with respect to a leading-order calculation. We study different dynamical scale choices, and find that the total transverse energy is significantly better than choices used in previous phenomenological studies. We compute the one-loop matrix elements using on-shell methods, as numerically implemented in the BlackHat code. The remaining parts of the calculation, including generation of the real-emission contributions and integration over phase space, are handled by the SHERPA package.
Leading-order cross term correction of three-dimensional parabolic equation models.
Sturm, Frédéric
2016-01-01
The issue of handling a leading-order cross-multiplied term in three-dimensional (3D) parabolic equation (PE) based models is addressed. In particular, numerical results obtained incorporating a leading-order cross-term correction in an existing 3D PE model, written in cylindrical coordinates, based on higher-order Padé approximations in both depth and azimuth, and a splitting operator technique are reported. Note that the numerical algorithm proposed in this paper could be used in the future to update any 3D PE codes that neglect cross terms and use a splitting numerical technique. The 3D penetrable wedge benchmark problem is chosen to illustrate the accuracy of the now-fully wide-angle enhanced 3D PE model. The comparisons with a 3D reference solution based on the image source clearly show that handling the leading-order cross term in the 3D PE computation is sufficient to remove the phase errors inherent to any 3D PE models that neglect cross terms in their formulations.
Leading-order hadronic contributions to the lepton anomalous magnetic moments from the lattice
Burger, Florian [OakLabs GmbH, Hennigsdorf (Germany); Feng, Xu [Columbia University, New York, NY (United States). Dept. of Physics; Jansen, Karl [DESY Zeuthen (Germany). NIC; Petschlies, Marcus [Bonn Univ. (Germany). Inst. fuer Strahlen- und Kernphysik; Pientka, Grit [Humboldt-Univ. Berlin (Germany). Inst. fuer Physik; Renner, Dru B. [Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
2015-11-15
The hadronic leading-order (hlo) contribution to the lepton anomalous magnetic moments a{sup hlo}{sub l} of the Standard Model leptons still accounts for the dominant source of the uncertainty of the Standard Model estimates. We present the results of an investigation of the hadronic leading order anomalous magnetic moments of the electron, muon and tau lepton from first principles in twisted mass lattice QCD. With lattice data for multiple pion masses in the range 230 MeV
Next-to-Leading Order Corrections to Higgs Boson Pair Production in Gluon Fusion
Kerner, Matthias
2016-01-01
We present a calculation of the next-to-leading order QCD corrections to the production of Higgs boson pairs in gluon fusion keeping the full dependence on the mass of the top quark. The virtual corrections, involving two-loop integrals with up to four mass scales, have been calculated numerically and we present an efficient algorithm to obtain accurate results of the virtual amplitude using numerical integrations. Taking the top quark mass into account we obtain significant differences compared to results obtained in the heavy top limit.
Leading order relativistic corrections to the dipole polarizability of the hydrogen molecular ions
Aznabayev, D T; Zhaugasheva, S A; Korobov, V I
2016-01-01
The static dipole polarizability for the hydrogen molecular ions H$_2^+$, HD$^+$, and D$_2^+$ are calculated. These new data for polarizability takes into account the leading order relativistic corrections to the wave function of the three-body system resulted from the Breit-Pauli Hamiltonian of $m\\alpha^4$ order. Our study covers a wide range of rotational ($L=0-5$) and vibrational ($v=0-10$) states, which are of practical interest for precision spectroscopy of the hydrogen molecular ions.
Higgs production in bottom-quark fusion: Matching beyond leading order
Forte, Stefano; Napoletano, Davide; Ubiali, Maria
2016-12-01
We compute the total cross-section for Higgs boson production in bottom-quark fusion using the so-called FONLL method for the matching of a scheme in which the b-quark is treated as a massless parton to that in which it is treated as a massive final-state particle, and extend our previous results to the case in which the next-to-next-to-leading-log five-flavour scheme result is combined with the next-to-leading-order O (αs3) four-flavour scheme computation.
Matching next-to-leading order predictions to parton showers in supersymmetric QCD
Degrande, Celine; Fuks, Benjamin; Hirschi, Valentin; Proudom, Josselin; Shao, Hua-Sheng
2016-01-01
We present a fully automated framework based on the FeynRules and MadGraph5 aMC@NLO programs that allows for accurate simulations of supersymmetric QCD processes at the LHC. Starting directly from a model Lagrangian that features squark and gluino interactions, event generation is achieved at the next-to-leading order in QCD, matching short-distance events to parton showers and including the subsequent decay of the produced supersymmetric particles. As an application, we study the impact of higher-order corrections in gluino pair-production in a simplified benchmark scenario inspired by current gluino LHC searches.
Matching next-to-leading order predictions to parton showers in supersymmetric QCD
Céline Degrande
2016-04-01
Full Text Available We present a fully automated framework based on the FeynRules and MadGraph5_aMC@NLO programs that allows for accurate simulations of supersymmetric QCD processes at the LHC. Starting directly from a model Lagrangian that features squark and gluino interactions, event generation is achieved at the next-to-leading order in QCD, matching short-distance events to parton showers and including the subsequent decay of the produced supersymmetric particles. As an application, we study the impact of higher-order corrections in gluino pair-production in a simplified benchmark scenario inspired by current gluino LHC searches.
QCD event generators with next-to-leading order matrix-elements and parton showers
Kurihara, Y; Ishikawa, T; Kato, K; Kawabata, S; Munehisa, T; Tanaka, H
2003-01-01
A new method to construct event-generators based on next-to-leading order QCD matrix-elements and leading-logarithmic parton showers is proposed. Matrix elements of loop diagram as well as those of a tree level can be generated using an automatic system. A soft/collinear singularity is treated using a leading-log subtraction method. Higher order re-summation of the soft/collinear correction by the parton shower method is combined with the NLO matrix-element without any double-counting in this method. An example of the event generator for Drell-Yan process is given for demonstrating a validity of this method.
Renormalization of an Abelian Tensor Group Field Theory: Solution at Leading Order
Lahoche, Vincent; Rivasseau, Vincent
2015-01-01
We study a just renormalizable tensorial group field theory of rank six with quartic melonic interactions and Abelian group U(1). We introduce the formalism of the intermediate field, which allows a precise characterization of the leading order Feynman graphs. We define the renormalization of the model, compute its (perturbative) renormalization group flow and write its expansion in terms of effective couplings. We then establish closed equations for the two point and four point functions at leading (melonic) order. Using the effective expansion and its uniform exponential bounds we prove that these equations admit a unique solution at small renormalized coupling.
Leading order hadronic contribution to g-2 from twisted mass QCD
Dru B Renner, Xu Feng, Karl Jansen, Marcus Petschlies
2010-06-01
We calculate the leading order hadronic contribution to the muon anomalous magnetic moment using twisted mass lattice QCD. The pion masses range from 330 MeV to 650 MeV. We use two lattice spacings, a=0.079 fm and 0.063 fm, to study lattice artifacts. Finite-size effects are studied for two values of the pion mass, and we calculate the disconnected contributions for four ensembles. Particular attention is paid to the dominant contributions of the vector mesons, both phenomenologically and from our lattice calculation.
$B^0-\\bar{B}^0$ Mixing at Next-to-Leading Order
Grozin, Andrey G; Mannel, Thomas; Pivovarov, Alexei A
2016-01-01
We compute the perturbative corrections to the HQET sum rules for the matrix element of the \\Delta B=2 operator that determines the mass shift of $B^0$, $\\bar{B}^0$ states. Technically, we obtain analytically the non-factorizable contributions at order $\\alpha_s$ to the bag parameter that first appear at the three-loop level. Together with the known non-perturbative corrections due to vacuum condensates and $1/m_b$ corrections, the full next-to-leading order result is now available. We present a numerical value for the renormalization group invariant bag parameter that is phenomenologically relevant and discuss comparison with recent lattice determinations.
Next-to-leading order QCD analysis of polarized deep inelastic scattering data
Abe, K.; Akagi, Takami; Anderson, B. D.; Anthony, P.L.; Arnold, Raymond G.; Averett, T.; Brand, H.R.; Berisso, C. M.; Bogorad, P.; Borel, H.; Bosted, P.E.; Breton, V.; Buenerd, Michel J.; Cates, Gordon D.; Chupp, Timothy E.
1997-01-01
We present a Next-to-Leading order perturbative QCD analysis of world data on the spin dependent structure functions $g_1^p, g_1^n$, and $g_1^d$, including the new experimental information on the $Q^2$ dependence of $g_1^n$. Careful attention is paid to the experimental and theoretical uncertainties. The data constrain the first moments of the polarized valence quark distributions, but only qualitatively constrain the polarized sea quark and gluon distributions. The NLO results are used to de...
Next-to-Next-Leading Order analysis of electroweak vacuum stability and rising inflection point
Iacobellis, Giuseppe
2016-01-01
We show an analysis on the gauge-independent observables associated with two stationary configurations of the Standard Model (SM) potential (extrapolated to high energy at Next-to-Next-to-Leading-Order (NNLO)): i) the value of the top mass ensuring stability of the SM electroweak vacuum and ii) the value of the Higgs potential at a rising inflection point. We examine in detail and reappraise the experimental and theoretical uncertainties which plague their determination, keeping alive the possibility for the SM of being stable and studying applications of such configuration to models of primordial inflation.
Chiral dynamics with (non)strange quarks
Kubis, Bastian; Meißner, Ulf-G.
2017-01-01
We review the results and achievements of the project B.3. Topics addressed include pion photoproduction off the proton and off deuterium, three-flavor chiral perturbation theory studies, chiral symmetry tests in Goldstone boson decays, the development of unitarized chiral perturbation theory to next-to-leading order, the two-pole structure of the Λ(1405), the dynamical generation of the lowest S11 resonances, the theory of hadronic atoms and its application to various systems, precision studies in light-meson decays based on dispersion theory, the Roy-Steiner analysis of pion-nucleon scattering, a high-precision extraction of the elusive pion-nucleon σ-term, and aspects of chiral dynamics in few-nucleon systems.
Improved next-to-leading order tidal heating and torquing of a Kerr black hole
Chatziioannou, Katerina; Poisson, Eric; Yunes, Nicolás
2016-10-01
We calculate the energy and angular-momentum fluxes across the event horizon of a tidally deformed, rapidly rotating black hole to next-to-leading order in the curvature of the external spacetime. These are expressed in terms of tidal quadrupole moments and their time derivatives, which provide a characterization of a generic tidal environment. As an application of our results, we provide an expression for the energy and angular-momentum fluxes across the horizon when the black hole is a member of a binary system on a slowly moving, quasicircular orbit. Our expressions are accurate to 1.5 post-Newtonian order beyond the leading-order fluxes, but they are valid for arbitrary mass ratios. We compare our results to those previously obtained in the case of an extreme mass ratio binary, and find that they do not agree at the 1.5 post-Newtonian order. We investigate a number of possible sources for this discrepancy, but are ultimately unable to resolve it.
Improved next-to-leading order tidal heating and torquing of a Kerr black hole
Chatziioannou, Katerina; Yunes, Nicolas
2016-01-01
We calculate the energy and angular momentum fluxes across the event horizon of a tidally deformed, rapidly rotating black hole to next-to-leading order in the curvature of the external spacetime. These are expressed in terms of tidal quadrupole moments and their time derivatives, which provide a characterization of a generic tidal environment. As an application of our results, we provide an expression for the energy and angular-momentum fluxes across the horizon when the black hole is a member of a binary system on a slowly-moving, quasi-circular orbit. Our expressions are accurate to 1.5 post-Newtonian order beyond the leading-order fluxes, but they are valid for arbitrary mass ratios. We compare our results to those previously obtained in the case of an extreme mass ratio binary, and find that they do not agree at the 1.5 post-Newtonian order. We investigate a number of possible sources for this discrepancy, but are ultimately unable to resolve it.
Multi-Parton Loop Amplitudes and Next-to-Leading Order Jet Cross-Sections
Bern, Zvi; Kosower, David A.; Signer, Adrian
1998-01-01
We review recent developments in the calculation of QCD loop amplitudes with several external legs, and their application to next-to-leading order jet production cross-sections. When a number of calculational tools are combined together --- helicity, color and supersymmetry decompositions, plus unitarity and factorization properties --- it becomes possible to compute multi-parton one-loop QCD amplitudes without ever evaluating analytically standard one-loop Feynman diagrams. One-loop helicity amplitudes are now available for processes with five external partons (ggggg, q\\bar{q}ggg and q\\bar{q}q'\\bar{q}'g), and for an intermediate vector boson V \\equiv \\gamma^*,Z,W plus four external partons (Vq\\bar{q}gg and Vq\\bar{q}q'\\bar{q}'). Using these amplitudes, numerical programs have been constructed for the next-to-leading order corrections to the processes p\\bar{p} to 3 jets (ignoring quark contributions so far) and e^+e^- to 4 jets.
Adolph, C.; Akhunzyanov, R.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anfimov, N.V.; Anosov, V.; Augustyniak, W.; Austregesilo, A.; Azevedo, C.D.R.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Chang, W.C.; Chiosso, M.; Choi, I.; Chung, S.U.; Cicuttin, A.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; M. Finger jr; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Grosse Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F.H.; Heitz, R.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; d'Hose, N.; Hsieh, C.Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Joosten, R.; Jorg, P.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.M.; Kramer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z.V.; Kulinich, Y.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.K.; Marchand, C.; Marianski, B.; Martin, A.; Marzec, J.; J.Matou s; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.V.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Mikhasenko, M.; Miyachi, Y.; Montuenga, P.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nukazuka, G.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.C.; Pereira, F.; M. Pe s; Peshekhonov, D.V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Roskot, M.; Rossiyskaya, N.S.; Ryabchikov, D.I.; Rybnikov, A.; Rychter, A.; Salac, R.; Samoylenko, V.D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I.A.; Sawada, T.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Seder, E.; Selyunin, A.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Smolik, J.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Tasevsky, M.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Vondra, J.; Weisrock, T.; Wilfert, M.; Wolbeek, J. ter; Zaremba, K.; Zavada, P.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.
2016-01-01
Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality $Q^2>1~({\\rm GeV}/c)^2$. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/$c$ polarised muon beam impinging on a polarised $^6$LiD target. By analysing the full range in hadron transverse momentum $p_T$, the different $p_T$-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation $\\Delta g/g$ is evaluated at leading order in pQCD at a hard scale of $\\mu^2 = \\langle Q^2\\rangle = 3(GeV=c)^2$. It is determined in three intervals of the nucleon momentum fraction carried by gluons, $x_g$, covering the range $0.04 \\!<\\! x_{ \\rm g}\\! <\\! 0.28$ . and does not exhibit a significant dependence on $x_{\\rm g}$. Average...
Differential Higgs boson pair production at next-to-next-to-leading order in QCD
Florian, Daniel de; Mazzitelli, Javier [UNSAM, Campus Miguelete, Buenos Aires (Argentina). International Center for Advanced Studies (ICAS); Grazzini, Massimiliano; Hanga, Catalin; Lindert, Jonas M. [Zuerich Univ. (Switzerland). Physik-Inst.; Kallweit, Stefan [Mainz Univ. (Germany). PRISMA Cluster of Excellence; Maierhoefer, Philipp [Freiburg Univ. (Germany). Physikalisches Inst.; Rathlev, Dirk [Deutsches Elektronen-Synchrotron, Hamburg (Germany). Theory Group
2016-06-15
We report on the first fully differential calculation for double Higgs boson production through gluon fusion in hadron collisions up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. The calculation is performed in the heavy-top limit of the Standard Model, and in the phenomenological results we focus on pp collisions at √(s)=14 TeV. We present differential distributions through NNLO for various observables including the transverse-momentum and rapidity distributions of the two Higgs bosons. NNLO corrections are at the level of 10%-25% with respect to the next-to-leading order (NLO) prediction with a residual scale uncertainty of 5%-15% and an overall mild phase-space dependence. Only at NNLO the perturbative expansion starts to converge yielding overlapping scale uncertainty bands between NNLO and NLO in most of the phase-space. The calculation includes NLO predictions for pp→HH+jet+X. Corrections to the corresponding distributions exceed 50% with a residual scale dependence of 20%-30%.
Event generation for next to leading order chargino production at the international linear collider
Robens, T.
2006-10-15
At the International Linear Collider (ILC), parameters of supersymmetry (SUSY) can be determined with an experimental accuracy matching the precision of next-to-leading order (NLO) and higher-order theoretical predictions. Therefore, these contributions need to be included in the analysis of the parameters. We present a Monte-Carlo event generator for simulating chargino pair production at the ILC at next-to-leading order in the electroweak couplings. We consider two approaches of including photon radiation. A strict fixed-order approach allows for comparison and consistency checks with published semianalytic results in the literature. A version with soft- and hard-collinear resummation of photon radiation, which combines photon resummation with the inclusion of the NLO matrix element for the production process, avoids negative event weights, so the program can simulate physical (unweighted) event samples. Photons are explicitly generated throughout the range where they can be experimentally resolved. In addition, it includes further higher-order corrections unaccounted for by the fixed-order method. Inspecting the dependence on the cutoffs separating the soft and collinear regions, we evaluate the systematic errors due to soft and collinear approximations for NLO and higher-order contributions. In the resummation approach, the residual uncertainty can be brought down to the per-mil level, coinciding with the expected statistical uncertainty at the ILC. We closely investigate the two-photon phase space for the resummation method. We present results for cross sections and event generation for both approaches. (orig.)
The Nd Break-Up Process in Leading Order in a Three-Dimensional Approach
Fachuddin, I; Glöckle, W; Elster, Ch.
2003-01-01
A three-dimensional approach based on momentum vectors as variables for solving the three nucleon Faddeev equation in first order is presented. The nucleon-deuteron break-up amplitude is evaluated in leading order in the NN T-matrix, which is also generated directly in three dimensions avoiding a summation of partial wave contributions. A comparison of semi-exclusive observables in the $d(p,n)pp$ reaction calculated in this scheme with those generated by a traditional partial wave expansion shows perfect agreement at lower energies. At about 200 MeV nucleon laboratory energies deviations in the peak of the cross section appear, which may indicate that special care is required in a partial wave approach for energies at and higher than 200 MeV. The role of higher order rescattering processes beyond the leading order in the NN T-matrix is investigated with the result, that at 200 MeV rescattering still provides important contributions to the cross section and certain spin observables. The influence of a relativi...
Adolph, C.; Akhunzyanov, R.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anfimov, N.V.; Anosov, V.; Augustyniak, W.; Austregesilo, A.; Azevedo, C.D.R.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Chang, W.C.; Chiosso, M.; Choi, I.; Chung, S.U.; Cicuttin, A.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; M. Finger jr; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Grosse Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F.H.; Heitz, R.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; d'Hose, N.; Hsieh, C.Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Joosten, R.; Jorg, P.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.M.; Kramer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z.V.; Kulinich, Y.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.K.; Marchand, C.; Marianski, B.; Martin, A.; Marzec, J.; J.Matou s; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.V.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Mikhasenko, M.; Miyachi, Y.; Montuenga, P.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nukazuka, G.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.C.; Pereira, F.; M. Pe s; Peshekhonov, D.V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Roskot, M.; Rossiyskaya, N.S.; Ryabchikov, D.I.; Rybnikov, A.; Rychter, A.; Salac, R.; Samoylenko, V.D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I.A.; Sawada, T.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Seder, E.; Selyunin, A.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Smolik, J.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Tasevsky, M.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Vondra, J.; Weisrock, T.; Wilfert, M.; Wolbeek, J. ter; Zaremba, K.; Zavada, P.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.
2017-01-01
Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality $Q^2>1~({\\rm GeV}/c)^2$. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/$c$ polarised muon beam impinging on a polarised $^6$LiD target. By analysing the full range in hadron transverse momentum $p_T$, the different $p_T$-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation $\\Delta g/g$ is evaluated at leading order in pQCD at a hard scale of $\\mu^2 = \\langle Q^2\\rangle = 3(GeV=c)^2$. It is determined in three intervals of the nucleon momentum fraction carried by gluons, $x_g$, covering the range $0.04 \\!<\\! x_{ \\rm g}\\! <\\! 0.28$ . and does not exhibit a significant dependence on $x_{\\rm g}$. Average...
Differential Higgs Boson Pair Production at Next-to-Next-to-Leading Order in QCD
de Florian, Daniel; Hanga, Catalin; Kallweit, Stefan; Lindert, Jonas M; Maierhöfer, Philipp; Mazzitelli, Javier; Rathlev, Dirk
2016-01-01
We report on the first fully differential calculation for double Higgs boson production through gluon fusion in hadron collisions up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. The calculation is performed in the heavy-top limit of the Standard Model, and in the phenomenological results we focus on pp collisions at 14 TeV. We present differential distributions through NNLO for various observables including the transverse-momentum and rapidity distributions of the two Higgs bosons. NNLO corrections are at the level of 10%-25% with respect to the next-to-leading order (NLO) prediction with a residual scale uncertainty of 5%-15% and an overall mild phase-space dependence. Only at NNLO the perturbative expansion starts to converge yielding overlapping scale uncertainty bands between NNLO and NLO in most of the phase-space. The calculation includes NLO predictions for pp -> HH+jet+X. Corrections to the corresponding distributions exceed 50% with a residual scale dependence of 20%-30%.
Differential Higgs boson pair production at next-to-next-to-leading order in QCD
de Florian, Daniel; Grazzini, Massimiliano; Hanga, Catalin; Kallweit, Stefan; Lindert, Jonas M.; Maierhöfer, Philipp; Mazzitelli, Javier; Rathlev, Dirk
2016-09-01
We report on the first fully differential calculation for double Higgs boson production through gluon fusion in hadron collisions up to next-to-next-to-leading order (NNLO) in QCD perturbation theory. The calculation is performed in the heavy-top limit of the Standard Model, and in the phenomenological results we focus on pp collisions at √{s}=14 TeV. We present differential distributions through NNLO for various observables including the transverse-momentum and rapidity distributions of the two Higgs bosons. NNLO corrections are at the level of 10%-25% with respect to the next-to-leading order (NLO) prediction with a residual scale uncertainty of 5%-15% and an overall mild phase-space dependence. Only at NNLO the perturbative expansion starts to converge yielding overlapping scale uncertainty bands between NNLO and NLO in most of the phase-space. The calculation includes NLO predictions for pp → HH + jet + X. Corrections to the corresponding distributions exceed 50% with a residual scale dependence of 20%-30%.
Leading-order hadronic contributions to the lepton anomalous magnetic moments from the lattice
Burger, Florian; Jansen, Karl; Petschlies, Marcus; Pientka, Grit; Renner, Dru B
2015-01-01
The hadronic leading-order (hlo) contribution to the lepton anomalous magnetic moments $a_l^\\mathrm{hlo}$ of the Standard Model leptons still accounts for the dominant source of the uncertainty of the Standard Model estimates. We present the results of an investigation of the hadronic leading order anomalous magnetic moments of the electron, muon and tau lepton from first principles in twisted mass lattice QCD. With lattice data for multiple pion masses in the range $230 \\mathrm{~MeV} \\lesssim m_{PS} \\lesssim 490 \\mathrm{~MeV}$, multiple lattice volumes and three lattice spacings we perform the extrapolation to the continuum and to the physical pion mass and check for all systematic uncertainties in the lattice calculation. As a result we calculate $a_{l}^\\mathrm{hlo}$ for the three Standard Model leptons with controlled statistical and systematic error in agreement with phenomenological determinations using dispersion relations and experimental data. In addition, we also give a first estimate of the hadronic...
Floss, H.G. [Univ. of Washington, Seattle, WA (United States)
1994-12-01
This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.
Next-to-leading order QCD corrections to the production of two bottom-antibottom pairs at the LHC.
Greiner, Nicolas; Guffanti, Alberto; Reiter, Thomas; Reuter, Jürgen
2011-09-02
We report the results of a computation of the full next-to-leading order QCD corrections to the production of two bb pairs at the LHC. This calculation at the parton level provides predictions for well separated b jets. The results show that the next-to-leading order corrections lead to an enhancement of the cross section for the central scale choice by roughly 50% with respect to the leading order result. The theoretical uncertainty estimated by variation of the renormalization and factorization scales is strongly reduced by the inclusion of next-to-leading order corrections.
Study of beauty quark production and next-to-leading order at HERA
Nuncio Quiroz, Adriana Elizabeth
2008-08-15
In this thesis a study on the production and evolution of beauty quarks in ep collisions at HERA is presented. The emphasis is put on the corresponding Quantum Chromodynamics predictions including next-to-leading order corrections. In the context of this work the FMNR x Pythia interface was developed, which calculates next-to-leading order Quantum Chromodynamics predictions at visible level for heavy-flavour processes in the photoproduction regime. This is achieved using the RedStat routines which transform the FMNR program into a Monte Carlo-like event generator. The parton-level events obtained are interfaced to Pythia using the Le Houches accord routines. All branching ratios and decay channels of the heavy quarks implemented in the Pythia framework are used, and therefore complex cuts on the nal state can be applied. The FMNR x Pythia interface is applied in this thesis to obtain next-to-leading order predictions for the recently finished heavy flavour ZEUS analyses: the ep {yields} b anti bX {yields} D{sup *}{mu}X' and ep {yields} b anti bX {yields} {mu}{sup +}{mu}{sup -}X' channels. A comparison with the H1 D{sup *}{mu} measurement is also performed. Since the use of such double tagging techniques to identify events where heavy flavours are present proved to be very convenient when the nal state is a pair of leptons, another part of this thesis work deals with the implementation of an electron finder, the {sup G}Elec finder. This finder is tested on the reconstruction of the J/{psi} {yields} e{sup +}e{sup -} signal. Finally, a heavy-flavour analysis has been started, namely the ep {yields} b anti bX {yields} e{mu}X' dilepton channel, using an integrated luminosity of 114 pb{sup -1} gated by the ZEUS detector in the years 1996-2000. Compared to previous analyses the study of beauty quark production in this channel extends the phase space of the measurement closer to the kinematic threshold, since electrons provide access to lower p{sub T} values
Transverse momentum broadening in semi-inclusive deep inelastic scattering at next-to-leading order
Kang, Zhong-Bo; Wang, Enke; Wang, Xin-Nian; Xing, Hongxi
2016-12-01
Within the framework of higher-twist collinear factorization, transverse momentum broadening for the final hadrons in semi-inclusive deeply inelastic e +A collisions is studied at the next-to-leading order (NLO) in perturbative QCD. Through explicit calculations of real and virtual corrections at twist 4, the transverse-momentum-weighted differential cross section due to double scattering is shown to factorize at NLO and can be expressed as a convolution of twist-4 nuclear parton correlation functions, the usual twist-2 fragmentation functions and hard parts which are finite and free of any divergences. A QCD evolution equation is also derived for the renormalized twist-4 quark-gluon correlation function which can be applied to future phenomenological studies of transverse momentum broadening and jet quenching at NLO.
Next-to-next-leading order correction to 3-jet rate and event-shape distribution
Mohammad Ebrahim Zomorrodian; Alireza Sepehri; Tooraj Ghaffary; Parvin Eslami
2011-01-01
The hadronic events from the + − annihilation data at the centre-of-mass energies ranging from 60 to 197 GeV were studied. The AMY and OPAL Collaborations offered a unique opportunity to test QCD by measuring the energy dependence of different observables. The coupling constant, , was measured by two different methods: first by employing the three-jet observables. Combining all the data, the value of as at next-to-next leading order (NNLO) was determined to be 0.117 ± 0.004(hard) ± 0.006(theo). Secondly, from the event-shape distributions, the strong coupling constant, , was extracted at NNLO and it’s evaluation was tested with the energy scale. The results were consistent with the running of , expected from QCD predictions. Averaging over different observables, was determined to be 0.115 ± 0.007(hard) ± 0.003(theo).
Automatic predictions in the Georgi-Machacek model at next-to-leading order accuracy
Degrande, Celine; Logan, Heather E; Peterson, Andrea D; Zaro, Marco
2015-01-01
We study the phenomenology of the Georgi-Machacek model at next-to-leading order (NLO) in QCD matched to parton shower, using a fully-automated tool chain based on MadGraph5_aMC@NLO and FeynRules. We focus on the production of the fermiophobic custodial fiveplet scalars H_5^0, H_5^+/-, and H_5^++/-- through vector boson fusion (VBF), associated production with a vector boson (V H_5), and scalar pair production (H_5 H_5). For these production mechanisms we compute NLO corrections to production rates as well as to differential distributions. Our results demonstrate that the Standard Model (SM) overall K-factors for such processes cannot in general be directly applied to beyond-the-SM distributions, due both to differences in the scalar electroweak charges and to variation of the K-factors over the differential distributions.
Towards semi-inclusive deep inelastic scattering at next-to-next-to-leading order
Anderle, Daniele; de Florian, Daniel; Rotstein Habarnau, Yamila
2017-02-01
In this paper, we compute the first set of O (αs2) corrections to semi-inclusive deep inelastic scattering structure functions. We start by studying the impact of the contribution of the partonic subprocesses that open at this order for the longitudinal structure function. We perform the full calculation analytically, and obtain the expression of the factorized cross section at this order. Special care is given to the study of their flavor decomposition structure. We analyze the phenomenological effect of the corrections finding that, even though expected to be small a priori, it turns out to be sizable with respect to the previous order known, calling for a full next-to-next-to-leading order calculation.
Next-to-Leading Order {QCD} Predictions for $Z, \\gamma^*$ + 3-Jet Distributions at the Tevatron
Berger, C.F.; Dixon, Lance J.; Febres Cordero, F.; Forde, D.; Gleisberg, T.; Ita, H.; Kosower, D.A.; Maitre, D.
2010-01-01
Using BlackHat in conjunction with SHERPA, we have computed next-to-leading order QCD predictions for a variety of distributions in Z,gamma*+1,2,3-jet production at the Tevatron, where the Z boson or off-shell photon decays into an electron-positron pair. We find good agreement between the NLO results for jet p_T distributions and measurements by CDF and D0. We also present jet-production ratios, or probabilities of finding one additional jet. As a function of vector-boson p_T, the ratios have distinctive features which we describe in terms of a simple model capturing leading logarithms and phase-space and parton-distribution-function suppression.
Next-to-Leading Order Jet Physics with BlackHat
Berger, C F; Dixon, L J; Cordero, F Febres; Forde, D; Gleisberg, T; Ita, H; Kosower, D A; Maitre, D
2009-01-01
We present several results obtained using the BlackHat next-to-leading order QCD program library, in conjunction with SHERPA. In particular, we present distributions for vector boson plus 1,2,3-jet production at the Tevatron and at the asymptotic running energy of the Large Hadron Collider, including new Z+3-jet distributions. The Z+2-jet predictions for the second-jet P_T distribution are compared to CDF data. We present the jet-emission probability at NLO in W+2-jet events at the LHC, where the tagging jets are taken to be the ones furthest apart in pseudorapidity. We analyze further the large left-handed W polarization, identified in our previous study, for W bosons produced at high P_T at the LHC.
Single top production at next-to-leading order in the Standard Model effective field theory
Zhang, Cen
2016-01-01
Single top production processes at hadron collider provide information on the relation between the top quark and the electroweak sector of the standard model. We compute the next-to-leading order QCD corrections to the three main production channels: $t$-channel, $s$-channel and $tW$ associated production, in the standard model including operators up to dimension-six. The calculation can be matched to parton shower programs and can therefore be directly used in experimental analyses. The QCD corrections are found to significantly impact the extraction of the current limits on the operators, because both of an improved accuracy and a better precision of the theoretical predictions. In addition, the distributions of some of the key discriminating observables are modified in a nontrivial way, which could change the interpretation of measurements in terms of UV complete models.
Dijet photoproduction of massless charm jets at next-to-leading order of QCD
Klasen, M
2011-01-01
We compute the charm dijet photoproduction cross section at next-to-leading order of QCD in the zero-mass variable flavour number scheme, i.e. with active charm quarks in the proton and photon. The results are compared to recent measurements from the ZEUS experiment at HERA. The predictions for various distributions agree well with the data, in particular for large momentum fractions of the the partons in the photon, where direct photon processes dominate. At low momentum fractions, the predictions are quite sensitive to the charm content in the photon. The experimental data are shown to favour parameterizations with a substantial charm quark density such as the one proposed by Cornet et al.
Dijet photoproduction of massless charm jets at next-to-leading order of QCD
Klasen, Michael [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Theoretische Physik, Muenster (Germany); Kramer, Gustav [Universitaet Hamburg, II. Institut fuer Theoretische Physik, Hamburg (Germany)
2011-10-15
We compute the charm dijet photoproduction cross section at next-to-leading order of QCD in the zero-mass variable flavour number scheme, i.e. with active charm quarks in the proton and photon. The results are compared to recent measurements from the ZEUS experiment at HERA. The predictions for various distributions agree with the data, in particular for large momentum fractions of the partons in the photon, where direct photon processes dominate. At low momentum fractions, the predictions are quite sensitive to the charm content in the photon. The experimental data are shown to favour parameterizations with a substantial charm-quark density such as the one proposed by Cornet et al. (orig.)
Dijet photoproduction of massless charm jets at next-to-leading order of QCD
Klasen, Michael; Kramer, Gustav
2011-10-01
We compute the charm dijet photoproduction cross section at next-to-leading order of QCD in the zero-mass variable flavour number scheme, i.e. with active charm quarks in the proton and photon. The results are compared to recent measurements from the ZEUS experiment at HERA. The predictions for various distributions agree with the data, in particular for large momentum fractions of the partons in the photon, where direct photon processes dominate. At low momentum fractions, the predictions are quite sensitive to the charm content in the photon. The experimental data are shown to favour parameterizations with a substantial charm-quark density such as the one proposed by Cornet et al.
Dijet photoproduction of massless charm jets at next-to-leading order of QCD
Klasen, Michael [Muenster Univ. (Germany). Inst. fuer Theoretische Physik; Kramer, Gustav [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik
2011-04-15
We compute the charm dijet photoproduction cross section at next-to-leading order of QCD in the zero-mass variable flavour number scheme, i.e. with active charm quarks in the proton and photon. The results are compared to recent measurements from the ZEUS experiment at HERA. The predictions for various distributions agree well with the data, in particular for large momentum fractions of the the partons in the photon, where direct photon processes dominate. At low momentum fractions, the predictions are quite sensitive to the charm content in the photon. The experimental data are shown to favour parameterizations with a substantial charm quark density such as the one proposed by Cornet et al. (orig.)
Colour-electric spectral function at next-to-leading order
Burnier, Y; Langelage, J; Mether, L
2010-01-01
The spectral function related to the correlator of two colour-electric fields along a Polyakov loop determines the momentum diffusion coefficient of a heavy quark near rest with respect to a heat bath. We compute this spectral function at next-to-leading order, O(alpha_s^2), in the weak-coupling expansion. The high-frequency part of our result (omega >> T), which is shown to be temperature-independent, is accurately determined thanks to asymptotic freedom; the low-frequency part of our result (omega 0. We also evaluate the colour-electric Euclidean correlator, which could be directly compared with lattice simulations. As an aside we determine the Euclidean correlator in the lattice strong-coupling expansion, showing that through a limiting procedure it can in principle be defined also in the confined phase of pure Yang-Mills theory, even if a practical measurement could be very noisy there.
Butenschoen, Mathias; Kniehl, Bernd A. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik
2009-09-15
We calculate the cross section of inclusive direct J/{psi} photoproduction at next-to-leading order within the factorization formalism of nonrelativistic quantum chromodynamics, for the first time including the full relativistic corrections due to the intermediate {sup 1}S{sub 0}{sup [8]}, {sup 3}S{sub 1}{sup [8]}, and {sup 3}P{sub J}{sup [8]} color-octet states. A comparison of our results to recent H1 data suggests that the color octet mechanism is indeed realized in J/{psi} photoproduction, although the predictivity of our results still suffers from uncertainties in the color-octet long-distance matrix elements. (orig.)
A ZEUS next-to-leading-order QCD analysis of data on deep inelastic scattering
Chekanov, S; Adamczyk, L; Adamus, M; Adler, V; Aghuzumtsyan, G; Allfrey, P D; Antonioli, P; Antonov, A; Arneodo, M; Bailey, D S; Bamberger, A; Barakbaev, A N; Barbagli, G; Barbi, M; Bari, G; Barreiro, F; Bartsch, D; Basile, M; Behrens, U; Bell, M A; Bellagamba, L; Bellan, P M; Benen, A; Bertolin, A; Bhadra, S; Bloch, I; Bold, T; Boos, E G; Borras, K; Boscherini, D; Brock, I; Brook, N H; Brugnera, R; Brümmer, N; Bruni, A; Bruni, G; Bussey, P J; Butterworth, J M; Büttner, C; Bylsma, B; Caldwell, A; Capua, M; Cara Romeo, G; Carli, T; Carlin, R; Cassel, D G; Catterall, C D; Chwastowski, J; Abramowicz, H; Ciborowski, J; Ciesielski, R; Cifarelli, Luisa; Cindolo, F; Cole, J E; Collins-Tooth, C; Contin, A; Cooper-Sarkar, A M; Coppola, N; Corradi, M; Corriveau, F; Costa, M; Cottrell, A; Cui, Y; D'Agostini, G; Dal Corso, F; Danilov, P; De Pasquale, S; Dementiev, R K; Derrick, M; Devenish, R C E; Dhawan, S; Dobur, D; Dolgoshein, B A; Doyle, A T; Drews, G; Durkin, L S; Dusini, S; Eisenberg, Y; Ermolov, P F; Eskreys, Andrzej; Everett, A; Ferrando, J; Ferrero, M I; Figiel, J; Foster, B; Foudas, C; Fourletov, S; Fourletova, J; Fry, C; Gabareen, A; Galas, A; Gallo, E; Garfagnini, A; Geiser, A; Genta, C; Gialas, I; Giusti, P; Gladilin, L K; Gladkov, D; Glasman, C; Göbel, F; Goers, S; Goncalo, R; González, O; Gosau, T; Göttlicher, P; Grabowska-Bold, I; Graciani-Díaz, R; Grigorescu, G; Grijpink, S; Groys, M; Grzelak, G; Gutsche, O; Gwenlan, C; Haas, T; Hain, W; Hall-Wilton, R; Hamatsu, R; Hamilton, J; Hanlon, S; Hart, C; Hartmann, H; Hartner, G; Heaphy, E A; Heath, G P; Helbich, M; Hilger, E; Hochman, D; Holm, U; Horn, C; Iacobucci, G; Iga, Y; Irrgang, P; Jakob, H P; Jiménez, M; Jones, T W; Kagawa, S; Kahle, B; Kaji, H; Kananov, S; Karshon, U; Karstens, F; Kasemann, M; Kataoka, M; Katkov, I I; Kcira, D; Keramidas, A; Khein, L A; Kim, J Y; Kind, O; Kisielewska, D; Kitamura, S; Koffeman, E; Kohno, T; Kooijman, P; Koop, T; Korzhavina, I A; Kotanski, A; Kötz, U; Kowal, A M; Kowalski, H; Kramberger, G; Kreisel, A; Krumnack, N; Kulinski, P; Kuze, M; Kuzmin, V A; Labarga, L; Lammers, S; Lelas, D; Levchenko, B B; Levy, A; Li, L; Lightwood, M S; Lim, H; Limentani, S; Ling, T Y; Liu, C; Liu, X; Löhr, B; Lohrmann, E; Loizides, J H; Long, K R; Longhin, A; Lukasik, J; Lukina, O Yu; Luzniak, P; Ma, K J; Maddox, E; Magill, S; Malka, J; Mankel, R; Margotti, A; Marini, G; Martin, J F; Martínez, M; Mastroberardino, A; Matsuzawa, K; Mattingly, M C K; Melzer-Pellmann, I A; Menary, S R; Metlica, F; Meyer, U; Miglioranzi, S; Milite, M; Mirea, A; Monaco, V; Montanari, A; Musgrave, B; Nagano, K; Namsoo, T; Nania, R; Nguyen, C N; Nigro, A; Ning, Y; Noor, U; Notz, D; Nowak, R J; Nuncio-Quiroz, A E; Oh, B Y; Olkiewicz, K; Ota, O; Padhi, S; Palmonari, F; Patel, S; Paul, E; Pavel, Usan; Pawlak, J M; Pelfer, P G; Pellegrino, A; Pesci, A; Piotrzkowski, K; Plamondon, M; Plucinsky, P P; Pokrovskiy, N S; Polini, A; Proskuryakov, A S; Przybycien, M B; Rautenberg, J; Raval, A; Reeder, D D; Ren, Z; Renner, R; Repond, J; Ri, Y D; Rinaldi, L; Robins, S; Rosin, M; Ruspa, M; Ryan, P; Sacchi, R; Salehi, H; Santamarta, R; Sartorelli, G; Savin, A A; Saxon, D H; Schagen, S; Schioppa, M; Schlenstedt, S; Schleper, P; Schmidke, W B; Schneekloth, U; Schörner-Sadenius, T; Sciulli, F; Shcheglova, L M; Skillicorn, I O; Slominski, W; Smith, W H; Soares, M; Solano, A; Son, D; Sosnovtsev, V V; Stairs, D G; Stanco, L; Standage, J; Stifutkin, A; Stonjek, S; Stopa, P; Stösslein, U; Straub, P B; Suchkov, S; Susinno, G; Suszycki, L; Sutiak, J; Sutton, M R; Sztuk, J; Szuba, D; Szuba, J; Tapper, A D; Targett-Adams, C; Tassi, E; Tawara, T; Terron, J; Tiecke, H G; Tokushuku, K; Tsurugai, T; Turcato, M; Tymieniecka, T; Tyszkiewicz, A; Ukleja, A; Ukleja, J; Vázquez, M; Vlasov, N N; Voss, K C; Walczak, R; Walsh, R; Wang, M; Whitmore, J J; Whyte, J; Wichmann, K; Wick, K; Wiggers, L; Wills, H H; Wing, M; Wlasenko, M; Wolf, G; Yagues-Molina, A G; Yamada, S; Yamazaki, Y; Yoshida, R; Youngman, C; Zambrana, M; Zawiejski, L; Zeuner, W; Zhautykov, B O; Zhou, C; Zichichi, A; Ziegler, A; Zotkin, D S; Zotkin, S A; De Favereau, J; De Wolf, E; Del Peso, J
2003-01-01
Next-to-leading order QCD analyses of the ZEUS data on deep inelastic scattering together with fixed-target data have been perfomed, from which the gluon and the quark densities of the proton and the value of the strong coupling constant, alpha_s(M_Z), were extracted. The study includes a full treatment of the experimental systematic uncertainties including point-to-point correlations. The resulting uncertainties in the parton density functions are presented. A combined fit for alpha_s(M_Z) and the gluon and qurak densities yields a value of alpha_s(M_Z) in agreement with the world average. The parton density functions derived from ZEUS data alone indicate the importance of HERA data in determining sea quark and gluon distributions at low x. The limits of applicability of the theoretical formalism have been explored by comparing the fit predictions to ZEUS data at very low Q^2.
Degrande, Celine; Mawatari, Kentarou; Mimasu, Ken; Sanz, Veronica
2016-01-01
We study the impact of dimension-six operators of the standard model effective field theory relevant for vector-boson fusion and associated Higgs boson production at the LHC. We present predictions at the next-to-leading order accuracy in QCD that include matching to parton showers and that rely on fully automated simulations. We show the importance of the subsequent reduction of the theoretical uncertainties in improving the possible discrimination between effective field theory and standard model results, and we demonstrate that the range of the Wilson coefficient values allowed by a global fit to LEP and LHC Run I data can be further constrained by LHC Run II future results.
Degrande, Celine; Mawatari, Kentarou; Mimasu, Ken; Sanz, Veronica
2017-04-25
We study the impact of dimension-six operators of the standard model effective field theory relevant for vector-boson fusion and associated Higgs boson production at the LHC. We present predictions at the next-to-leading order accuracy in QCD that include matching to parton showers and that rely on fully automated simulations. We show the importance of the subsequent reduction of the theoretical uncertainties in improving the possible discrimination between effective field theory and standard model results, and we demonstrate that the range of the Wilson coefficient values allowed by a global fit to LEP and LHC Run I data can be further constrained by LHC Run II future results.
Coherent states, 6j symbols and properties of the next to leading order asymptotic expansions
Kamiński, Wojciech; Steinhaus, Sebastian
2013-12-01
We present the first complete derivation of the well-known asymptotic expansion of the SU(2) 6j symbol using a coherent state approach, in particular we succeed in computing the determinant of the Hessian matrix. To do so, we smear the coherent states and perform a partial stationary point analysis with respect to the smearing parameters. This allows us to transform the variables from group elements to dihedral angles of a tetrahedron resulting in an effective action, which coincides with the action of first order Regge calculus associated to a tetrahedron. To perform the remaining stationary point analysis, we compute its Hessian matrix and obtain the correct measure factor. Furthermore, we expand the discussion of the asymptotic formula to next to leading order terms, prove some of their properties and derive a recursion relation for the full 6j symbol.
Leading order multi-soft behaviors of tree amplitudes in NLSM
Du, Yi-Jian
2016-01-01
In this paper, we investigate multi-soft behaviors of tree amplitudes in nonlinear sigma model (NLSM). We prove that the leading behaviors of amplitudes with odd number of all adjacent soft pions are zero. We further propose and prove the leading behaviors of amplitudes with even number of all adjacent soft pions. The soft factors for this case are expressed in terms of products of the leading order Berends- Giele sub-currents in Cayley parametrization. Each sub-current in the expression contains at most one hard pion. We generalize our discussion to amplitudes containing arbitrary number of nonadjacent soft blocks: The leading behaviors of amplitudes where at least one soft block has odd number of adjacent soft pions are zero; The leading soft factors for amplitudes where all soft blocks containing even number of soft pions are given by products of soft factors for all blocks.
Next-to-leading Order Calculation for Jets Defined by a Maximized Jet Function
Kaufmann, Tom; Vogelsang, Werner
2014-01-01
We present a next-to-leading order QCD calculation for the single-inclusive production of collimated jets at hadron colliders, when the jet is defined by maximizing a suitable jet function that depends on the momenta of final-state particles in the event. A jet algorithm of this type was initially proposed by Georgi and subsequently further developed into the class of "$J_{E_T}$ algorithms". Our calculation establishes the infrared safety of the algorithms at this perturbative order. We derive analytical results for the relevant partonic cross sections. We discuss similarities and differences with respect to jets defined by cone or (anti-)$k_t$ algorithms and present numerical results for the Tevatron and the LHC.
Next-to-leading order QCD corrections to paired Bc production in e+e- annihilation
Berezhnoy, A. V.; Likhoded, A. K.; Onishchenko, A. I.; Poslavsky, S. V.
2017-02-01
We present theoretical analysis of paired Bc mesons production in e+e- annihilation at different energy scales taking into account full next-to-leading order QCD corrections. Both possible electroweak channels are considered: production via virtual photon and via virtual Z-boson. We study in detail the role of radiative QCD corrections, which were found to be significant especially at low energies. It is shown that the contribution from Z-boson is significant at high energies (√{ s} >MZ / 2) especially in the case of paired production of pseudo-scalar and vector (Bc +Bc*) mesons. Azimuthal asymmetry induced by a P-violating weak interaction with Z-boson is also analyzed.
On top-pair hadro-production at next-to-next-to-leading order
Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Uwer, P. [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Vogt, A. [Liverpool Univ. (United Kingdom). Dept. of Mathematical Sciences
2012-03-15
We study the QCD corrections at next-to-next-to-leading order (NNLO) to the cross section for the hadronic pair-production of top quarks. We present new results in the high-energy limit using the well-known framework of k{sub t}-factorization. We combine these findings with the known threshold corrections and present improved approximate NNLO results over the full kinematic range. This approach is employed to quantify the residual theoretical uncertainty of the approximate NNLO results which amounts to about 4% for the Tevatron and 5% for the LHC cross-section predictions. Our analytic results in the high-energy limit will provide an important check on future computations of the complete NNLO cross sections.
Leading order multi-soft behaviors of tree amplitudes in NLSM
Du, Yi-Jian; Luo, Hui
2017-03-01
In this paper, we investigate multi-soft behaviors of tree amplitudes in nonlinear sigma model (NLSM). The leading behaviors of amplitudes with odd number of all-adjacent soft pions are zero. We further propose and prove that leading soft factors of amplitudes with even number all-adjacent soft pions can be expressed in terms of products of the leading order Berends-Giele sub-currents in Cayley parametrization. Each subcurrent in the expression contains at most one hard pion. Discussions are generalized to amplitudes containing arbitrary number of nonadjacent soft blocks: the leading behaviors of amplitudes where at least one soft block has odd number of adjacent soft pions are zero; the leading soft factors for amplitudes where all soft blocks containing even number of soft pions are given by products of soft factors for these blocks.
Coherent states, 6j symbols and properties of the next to leading order asymptotic expansions
Kamiński, Wojciech, E-mail: wkaminsk@fuw.edu.pl [Wydział Fizyki, Uniwersytet Warszawski, Hoża 69, 00-681, Warsaw (Poland); Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada); Max Planck Institute for Gravitational Physics, Am Mühlenberg 1, D-14476 Potsdam (Germany); Steinhaus, Sebastian, E-mail: steinhaus.sebastian@gmail.com [Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, Ontario N2L 2Y5 (Canada); Max Planck Institute for Gravitational Physics, Am Mühlenberg 1, D-14476 Potsdam (Germany)
2013-12-15
We present the first complete derivation of the well-known asymptotic expansion of the SU(2) 6j symbol using a coherent state approach, in particular we succeed in computing the determinant of the Hessian matrix. To do so, we smear the coherent states and perform a partial stationary point analysis with respect to the smearing parameters. This allows us to transform the variables from group elements to dihedral angles of a tetrahedron resulting in an effective action, which coincides with the action of first order Regge calculus associated to a tetrahedron. To perform the remaining stationary point analysis, we compute its Hessian matrix and obtain the correct measure factor. Furthermore, we expand the discussion of the asymptotic formula to next to leading order terms, prove some of their properties and derive a recursion relation for the full 6j symbol.
Four-flavour leading-order hadronic contribution to the muon anomalous magnetic moment
Burger, Florian [Humboldt-Universität zu Berlin, Institut für Physik,Newtonstr. 15, D-12489 Berlin (Germany); Feng, Xu [High Energy Accelerator Research Organization (KEK),Tsukuba 305-0801 (Japan); Hotzel, Grit [Humboldt-Universität zu Berlin, Institut für Physik,Newtonstr. 15, D-12489 Berlin (Germany); Jansen, Karl [NIC, DESY,Platanenallee 6, D-15738 Zeuthen (Germany); Department of Physics, University of Cyprus,P.O.Box 20537, 1678 Nicosia (Cyprus); Petschlies, Marcus [The Cyprus Institute,P.O.Box 27456, 1645 Nicosia (Cyprus); Renner, Dru B. [Jefferson Lab,12000 Jefferson Avenue, Newport News, VA 23606 (United States); Collaboration: The ETM Collaboration
2014-02-24
We present a four-flavour lattice calculation of the leading-order hadronic vacuum polarisation contribution to the anomalous magnetic moment of the muon, a{sub μ}{sup hvp}, arising from quark-connected Feynman graphs. It is based on ensembles featuring N{sub f}=2+1+1 dynamical twisted mass fermions generated by the European Twisted Mass Collaboration (ETMC). Several light quark masses are used in order to yield a controlled extrapolation to the physical pion mass. We employ three lattice spacings to examine lattice artefacts and several different volumes to check for finite-size effects. Incorporating the complete first two generations of quarks allows for a direct comparison with phenomenological determinations of a{sub μ}{sup hvp}. Our final result including an estimate of the systematic uncertainty a{sub μ}{sup hvp}=6.74(21)(18)⋅10{sup −8} shows a good overall agreement with these computations.
Next-to-Leading Order Description of Nucleon Structure Function In Valon Model
Arash, F; Arash, Firooz; Khorramia, Ali Naghi
1999-01-01
We have improved and examined the applicability of the valon model where the structure of any hadron is determined by the structure of its constituent quarks. Nucleon structure functions are calculated within this model in the Next-to-Leading order. The results compare well with the experimental data. The model handles the bound state problem and the calculations show a flat or almost flat behavior for $F_{2}$ which sets in at some region of $x\\leq 10^{-5}$at fixed $Q^{2}$. The emergence of this behavior is a consequence of the model and was not put in a priori as a theoretical guess. It seems that such a flatness can be inferred from HERA data, although, not completely confirmed yet. A set of parton distributions are given and their evolutions are tested. Some qualitative implications of the model for the spin structure of the proton is discussed.
Next-to-Leading Order QCD Predictions for Z, gamma^* 3-Jet Distributions at the Tevatron
Berger, C.F.; /MIT, LNS; Bern, Z.; /UCLA; Dixon, L.J.; /SLAC; Cordero, F.Febres; /Simon Bolivar U.; Forde, D.; /CERN /NIKHEF, Amsterdam; Gleisberg, T.; /SLAC; Ita, H.; /UCLA; Kosower, D.A.; /DAPNIA, Saclay; Maitre, D.; /Durham U.
2010-06-02
Using BlackHat in conjunction with SHERPA, we have computed next-to-leading order QCD predictions for a variety of distributions in Z, {gamma}{sup {asterisk}}+ 1, 2, 3-jet production at the Tevatron, where the Z boson or off-shell photon decays into an electron-positron pair. We find good agreement between the NLO results for jet {sub pT} distributions and measurements by CDF and D0. We also present jetproduction ratios, or probabilities of finding one additional jet. As a function of vector-boson {sub pT} , the ratios have distinctive features which we describe in terms of a simple model capturing leading logarithms and phase-space and parton-distribution-function suppression.
Coherent states, 6j symbols and properties of the next to leading order asymptotic expansions
Kaminski, Wojciech
2013-01-01
We present the first complete derivation of the well-known asymptotic expansion of the SU(2) 6j symbol using a coherent state approach, in particular we succeed in computing the determinant of the Hessian matrix. To do so, we smear the coherent states and perform a partial stationary point analysis with respect to the smearing parameters. This allows us to transform the variables from group elements to dihedral angles of a tetrahedron resulting in an effective action, which coincides with the action of first order Regge calculus associated to a tetrahedron. To perform the remaining stationary point analysis, we compute its Hessian matrix and obtain the correct measure factor. Furthermore, we expand the discussion of the asymptotic formula to next to leading order terms, prove some of their properties and derive a recursion relation for the full 6j symbol.
Degrande, Celine [CERN, Theory Division, Geneva 23 (Switzerland); Fuks, Benjamin [Sorbonne Universites, UPMC Univ. Paris 06, Paris (France); CNRS, Paris (France); Mawatari, Kentarou [Universite Grenoble-Alpes, Laboratoire de Physique Subatomique et de Cosmologie, Grenoble (France); Vrije Universiteit Brussel, Theoretische Natuurkunde and IIHE/ELEM, International Solvay Institutes, Brussels (Belgium); Mimasu, Ken [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom); Universite catholique de Louvain, Centre for Cosmology, Particle Physics and Phenomenology (CP3), Louvain-la-Neuve (Belgium); Sanz, Veronica [University of Sussex, Department of Physics and Astronomy, Brighton (United Kingdom)
2017-04-15
We study the impact of dimension-six operators of the standard model effective field theory relevant for vector-boson fusion and associated Higgs boson production at the LHC. We present predictions at the next-to-leading order accuracy in QCD that include matching to parton showers and that rely on fully automated simulations. We show the importance of the subsequent reduction of the theoretical uncertainties in improving the possible discrimination between effective field theory and standard model results, and we demonstrate that the range of the Wilson coefficient values allowed by a global fit to LEP and LHC Run I data can be further constrained by LHC Run II future results. (orig.)
Direct Photon Production at Next-to–Next-to-Leading Order
Campbell, John M.; Ellis, R. Keith; Williams, Ciaran
2017-05-01
We present the first calculation of direct photon production at next-to-next-to leading order (NNLO) accuracy in QCD. For this process, although the final state cuts mandate only the presence of a single electroweak boson, the underlying kinematics resembles that of a generic vector boson plus jet topology. In order to regulate the infrared singularities present at this order we use the $N$-jettiness slicing procedure, applied for the first time to a final state that at Born level includes colored partons but no required jet. We compare our predictions to ATLAS 8 TeV data and find that the inclusion of the NNLO terms in the perturbative expansion, supplemented by electroweak corrections, provides an excellent description of the data with greatly reduced theoretical uncertainties.
Probing Chiral Interactions in Light Nuclei
Nogga, A; Barrett, B R; Meissner, U; Witala, H; Epelbaum, E; Kamada, H; Navratil, P; Glockle, W; Vary, J P
2004-01-08
Chiral two- and three-nucleon interactions are studied in a few-nucleon systems. We investigate the cut-off dependence and convergence with respect to the chiral expansion. It is pointed out that the spectra of light nuclei are sensitive to the three-nucleon force structure. As an example, we present calculations of the 1{sup +} and 3{sup +} states of {sup 6}Li using the no-core shell model approach. The results show contributions of the next-to-next-to-leading order terms to the spectra, which are not correlated to the three-nucleon binding energy prediction.
Adolph, C.; Braun, C.; Eyrich, W.; Lehmann, A.; Zink, A. [Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Aghasyan, M.; Birsa, R.; Dalla Torre, S.; Levorato, S.; Santos, C.; Sozzi, F.; Tessaro, S.; Tessarotto, F. [INFN, Trieste (Italy); Akhunzyanov, R.; Alexeev, G.D.; Anfimov, N.V.; Anosov, V.; Efremov, A.; Gavrichtchouk, O.P.; Guskov, A.; Ivanshin, Yu.; Kisselev, Yu.; Kouznetsov, O.M.; Kroumchtein, Z.V.; Meshcheryakov, G.V.; Nagaytsev, A.; Olshevsky, A.G.; Orlov, I.; Peshekhonov, D.V.; Rossiyskaya, N.S.; Rybnikov, A.; Savin, I.A.; Selyunin, A.; Shevchenko, O.Yu.; Slunecka, M.; Smolik, J.; Tasevsky, M.; Zavada, P.; Zemlyanichkina, E. [Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation); Alexeev, M.G. [University of Turin, Department of Physics, Turin (Italy); Amoroso, A.; Balestra, F.; Chiosso, M.; Gnesi, I.; Grasso, A.; Ivanov, A.; Kotzinian, A.M.; Longo, R.; Parsamyan, B.; Takekawa, S. [University of Turin, Department of Physics, Turin (Italy); INFN, Turin (Italy); Andrieux, V.; Boer, M.; Curiel, Q.; Ferrero, A.; Fuchey, E.; Hose, N. d'
2017-04-15
Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality Q{sup 2} > 1 (GeV/c){sup 2}. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam impinging on a polarised {sup 6}LiD target. By analysing the full range in hadron transverse momentum p{sub T}, the different p{sub T}-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation Δg/g is evaluated at leading order in pQCD at a hard scale of μ{sup 2} = left angle Q{sup 2} right angle = 3 (GeV/c){sup 2}. It is determined in three intervals of the nucleon momentum fraction carried by gluons, x{sub g}, covering the range 0.04 < x{sub g} < 0.28 and does not exhibit a significant dependence on x{sub g}. The average over the three intervals, left angle Δg/g right angle = 0.113 ± 0.038{sub (stat.)} ± 0.036{sub (syst.)} at left angle x{sub g} right angle ∼ 0.10, suggests that the gluon polarisation is positive in the measured x{sub g} range. (orig.)
Antikaon induced Ξ production from a chiral model at NLO
Feijoo A.
2014-01-01
Full Text Available We study the meson-baryon interaction in the strangeness S = −1 sector using a chiral unitary approach, paying particular attention to the K̄N → KΞ reaction, especially important for constraining the next-to-leading order chiral terms, and considering also the effect of high spin hyperonic resonances. We also present results for the production of Ξ hyperons in nuclei
One-loop Chiral Perturbation Theory with two fermion representations
DeGrand, Thomas; Neil, Ethan T; Shamir, Yigal
2016-01-01
We develop Chiral Perturbation Theory for chirally broken theories with fermions in two different representations of the gauge group. Any such theory has a non-anomalous singlet $U(1)_A$ symmetry, yielding an additional Nambu-Goldstone boson when spontaneously broken. We calculate the next-to-leading order corrections for the pseudoscalar masses and decay constants, which include the singlet Nambu-Goldstone boson, as well as for the two condensates. The results can be generalized to more than two representations.
Local chiral potentials with ${\Delta}$ -intermediate states and the structure of light nuclei
Piarulli, M.; Girlanda, L.; Schiavilla, R.; Kievsky, A.; Lovato, A.; Marcucci, L. E.; Pieper, Steven C.; Viviani, M.; Wiringa, R. B.
2016-11-01
We present fully local versions of the minimally non-local nucleon-nucleon potentials constructed in a previous paper [M.\\ Piarulli {\\it et al.}, Phys.\\ Rev.\\ C {\\bf 91}, 024003 (2015)], and use them in hypersperical-harmonics and quantum Monte Carlo calculations of ground and excited states of $^3$H/$^3$He, $^4$He, and $^6$He/$^6$Li nuclei. The long-range part of these local potentials includes one- and two-pion exchange contributions without and with $\\Delta$-isobars in the intermediate states up to order $Q^3$ ($Q$ denotes generically the low momentum scale) in the chiral expansion, while the short-range part consists of contact interactions up to order $Q^4$. The low-energy constants multiplying these contact interactions are fitted to the 2013 Granada database in two different ranges of laboratory energies, either 0--125 MeV or 0--200 MeV, and to the deuteron binding energy and $nn$ singlet scattering length. Fits to these data are performed for three models characterized by long- and short-range cutoffs, $R_{\\rm L}$ and $R_{\\rm S}$ respectively, ranging from $(R_{\\rm L},R_{\\rm S})=(1.2,0.8)$ fm down to $(0.8,0.6)$ fm. The long-range (short-range) cutoff regularizes the one- and two-pion exchange (contact) part of the potential.
Durães F.O.
2010-04-01
Full Text Available We apply the similarity renormalization group (SRG approach to evolve a nucleon-nucleon (N N interaction in leading-order (LO chiral eﬀective ﬁeld theory (ChEFT, renormalized within the framework of the subtracted kernel method (SKM. We derive a ﬁxed-point interaction and show the renormalization group (RG invariance in the SKM approach. We also compare the evolution of N N potentials with the subtraction scale through a SKM RG equation in the form of a non-relativistic Callan-Symanzik (NRCS equation and the evolution with the similarity cutoﬀ through the SRG transformation.
Zakharov V.I.
2015-01-01
Full Text Available We review briefly properties of chiral liquids, or liquids with massless fermionic constituents. We concentrate on three effects, namely, the low ratio of viscosity η to entropy density s, chiral magnetic and vortical effects. We sketch standard derivations of these effects in the hydrodynamic approximation and then concentrate on possibile unifying approach which is based on consideration of the (anomalously conserved axial current. The point is that the conservation of chirality is specific for the microscopic, field-theoretic description of massless fermions and their interactions. On the macroscopic side, the standard hydrodynamic equations are not consistent, generally speaking, with conservation of a helical macroscopic motion. Imposing extra constraints on the hydrodynamics might resolve this “clash-of-symmetries” paradox.
Topics on heavy baryon chiral perturbation theory in the large N_c limit
Flores-Mendieta, R
2002-01-01
We compute nonanalytical pion-loop corrections to baryon masses in a combined expansion in chiral symmetry breaking and 1/N_c, where N_c is the number of colors. Specifically, we compute flavor-27 baryon mass splittings at leading order in chiral perturbation theory. Our results, at the physical value N_c=3, are compared with the expressions obtained in heavy baryon chiral perturbation theory with no 1/N_c expansion.
Chiral Nanoscience and Nanotechnology
Dibyendu S. Bag; T.C. Shami; K.U. Bhasker Rao
2008-01-01
The paper reviews nanoscale science and technology of chiral molecules/macromolecules-under twosubtopics-chiral nanotechnology and nano-chiral technology. Chiral nanotechnology discusses thenanotechnology, where molecular chirality plays a role in the properties of materials, including molecularswitches, molecular motors, and other molecular devices; chiral supramolecules and self-assembled nanotubesand their functions are also highlighted. Nano-chiral technology describes the nanoscale appr...
Chiral random matrix theory for staggered fermions
Osborn, James C
2012-01-01
We present a completed random matrix theory for staggered fermions which incorporates all taste symmetry breaking terms at their leading order from the staggered chiral Lagrangian. This is an extension of previous work which only included some of the taste breaking terms. We will also discuss the effects of taste symmetry breaking on the eigenvalues in the weak and strong taste breaking limits, and compare with some results from lattice simulations.
Jet production at next-to-leading order in p+Au collisions at the RHIC
HE Yun-Cun; ZHANG Ben-Wei; WANG En-Ke
2012-01-01
We calculate jet productions in p+Au collisions at the RHIC at next-to-leading order with perturbative QCD.Inclusive jet transverse energy spectrum,dijet invariant mass spectrum,dijet angular distribution,and corresponding nuclear modification factors for the three observables in p+Au collisions at √s =200 GeV are given,where the initial-state cold nuclear matter (CNM) effects are included by taking advantage of four parametrization sets of nuclear parton distribution functions (nPDFs)-EPS,nCTEQ,HKN and DS.We demonstrate that inclusive jet transverse energy (ET) spectrum,dijet invariant mass (MJJ) spectrum with all 4 nPDFs are increased at low ET or MJJ,whereas at high ET or MJJ large deviation of results with different nPDFs is observed.It is found that the dijet angular distributions in p+Au collisions do not vary relative to those in p+p collisions for all 4 nPDFs.
Virasoro vacuum block at next-to-leading order in the heavy-light limit
Beccaria, Matteo; Fachechi, Alberto; Macorini, Guido [Dipartimento di Matematica e Fisica Ennio De Giorgi,Università del Salento & INFN, Via Arnesano, 73100 Lecce (Italy)
2016-02-11
We consider the semiclassical limit of the vacuum Virasoro block describing the diagonal 4-point correlation functions on the sphere. At large central charge c, after exponentiation, it depends on two fixed ratios h{sub H}/c and h{sub L}/c, where h{sub H,L} are the conformal dimensions of the 4-point function operators. The semiclassical block may be expanded in powers of the light ratio h{sub L}/c and the leading non-trivial (linear) order is known in closed form as a function of h{sub H}/c. Recently, this contribution has been matched against AdS{sub 3} gravity calculations where heavy operators build up a classical geometry corresponding to a BTZ black hole, while the light operators are described by a geodesic in this background. Here, we compute for the first time the next-to-leading quadratic correction O((h{sub L}/c){sup 2}), again in closed form for generic heavy operator ratio h{sub H}/c. The result is a highly non-trivial extension of the leading order and may be relevant for further refined AdS{sub 3}/CFT{sub 2} tests. Applications to the two-interval Rényi entropy are also presented.
Leading-order hadronic contribution to the electron and muon g-2
Jegerlehner, Fred
2015-01-01
I present a new data driven update of the hadronic vacuum polarization effects for the muon and the electron g-2. For the leading order contributions I find a_mu[LO VP]=(688.57 +/-4.28)[688.91+/-3.52] 10^{-10} based on e+e- data [incl. tau data], a_mu[VP NLO]= (-9.92+/- 0.10) 10^{-10} and a_mu[VP NNLO]= (1.23+/- 0.01) 10^{-10} for the muon, and a_e[VP LO]=(185.11+/- 1.24) 10^{-14}, a_e[VP NLO]=(-22.15+/- 0.16) 10^{-14} and a_e[VP NNLO]=(2.80+/- 0.02) 10^{-14} for the electron. A problem with vacuum polarization undressing of cross-sections (time-like region) is addressed. I also add a comment on properly including axial mesons in the hadronic light-by-light scattering contribution. My estimate here reads a_mu[a_1,f_1',f_1] = ({ 7.51 +/- 2.71}) 10^{-11}. With these updates a_mu [exp]-a_mu [the]=(31.0+/- 8.2) 10^{-10} a 3.8 sigma deviation, while a_e [exp]-a_e [the]=(-1.14+/- 0.82) 10^{-12} shows no significant deviation.
Virasoro vacuum block at next-to-leading order in the heavy-light limit
Beccaria, Matteo; Macorini, Guido
2015-01-01
We consider the semiclassical limit of the vacuum Virasoro block describing the diagonal 4-point correlation functions on the sphere. At large central charge c, after exponentiation, it depends on two fixed ratios h_H/c and h_L/c, where h_{H, L} are the conformal dimensions of the 4-point function operators. The semiclassical block may be expanded in powers of the light ratio h_L/c and the leading non-trivial (linear) order is known in closed form as a function of h_H/c. Recently, this contribution has been matched against AdS_3 gravity calculations where heavy operators build up a classical geometry corresponding to a BTZ black hole, while the light operators are described by a geodesic in this background. Here, we compute for the first time the next-to-leading quadratic correction O((h_L/c)^{2}), again in closed form for generic heavy operator ratio h_H/c. The result is a highly non-trivial extension of the leading order and may be relevant for further refined AdS_{3}/CFT_{2} tests. Applications to the two-...
Gelis, F
2012-01-01
In [arXiv:0804.2630], we have analyzed the leading logarithms of energy that appear in the inclusive spectrum of gluons produced in heavy ion collisions, calculated in the Color Glass Condensate framework. The main result of this paper was that these logarithms are intrinsic properties of the colliding projectiles, and that they can be resummed by letting the distributions of color sources in the nuclei evolve according to the JIMWLK equation. An essential step in the proof of this factorization result is the calculation of the gluon spectrum at Next-to-Leading order, and in particular a functional relationship that expresses the NLO correction as the action of a certain operator on the LO spectrum. In this paper, we show that this type of relation between spectra at LO and NLO is not specific to the production of gluons, but that it is in fact generic for inclusive spectra in heavy ion collisions. To illustrate this, we compute up to NLO the inclusive spectrum of some hypothetical scalar fields, either color...
Leading-order determination of the gluon polarization from high-p{sub T} hadron electroproduction
Airapetian, A. [Giessen Univ. (Germany). Physikalisches Inst.; Michigan Univ., Ann Arbor, MI (United States). Randall Lab. of Physics; Akopov, N. [Yerevan Physics Inst. (Armenia); Akopov, Z. [DESY, Hamburg (DE)] (and others)
2010-02-15
Longitudinal double-spin asymmetries of charged hadrons with high transverse momentum p{sub T} have been measured in electroproduction using the Hermes detector at Hera. Processes involving gluons in the nucleon have been enhanced relative to others by selecting hadrons with p{sub T} typically above 1 GeV. In this kinematic domain the gluon polarization has been extracted in leading order making use of the model embedded in the Monte Carlo Generator Pythia 6.2. The gluon polarization obtained from single inclusive hadrons in the p{sub T} range 1 GeV
Production of Heavy neutrino in next-to-leading order QCD at the LHC and beyond
Das, Arindam; Majhi, Swapan
2016-01-01
Majorana and pseudo-Dirac heavy neutrinos are introduced into the type-I and inverse seesaw models, respectively, in explaining the naturally small neutrino mass. TeV scale heavy neutrinos can also be accommodated to have a sizable mixing with the Standard Model light neutrinos, through which they can be produced and detected at the high energy colliders. In this paper we consider the Next-to-Leading Order QCD corrections to the heavy neutrino production, and study the scale variation in cross-sections as well as the kinematic distributions with different final states at $14$ TeV LHC and also in the context of $100$ TeV hadron collider. The repertoire of the Majorana neutrino is realized through the characteristic signature of the same-sign dilepton pair, whereas, due to a small lepton number violation, the pseudo-Dirac heavy neutrino can manifest the trileptons associated with missing energy in the final state. Using the $\\sqrt{s}=8$ TeV, $20.3$ fb$^{-1}$ and $19.7$ fb$^{-1}$ data at the ATLAS and CMS respec...
Properties of Lithium-11 and Carbon-22 at leading order in halo effective field theory
Acharya Bijaya
2016-01-01
Full Text Available We study the 11Li and 22C nuclei at leading order (LO in halo effective field theory (Halo EFT. Using the value of the 22C rms matter radius deduced in Ref. [1] as an input in a LO calculation, we simultaneously constrain the values of the two-neutron (2n separation energy of 22C and the virtual-state energy of the 20C−neutron system (hereafter denoted 21C. The 1−σ uncertainty of the input rms matter radius datum, along with the theory error estimated from the anticipated size of the higher-order terms in the Halo EFT expansion, gives an upper bound of about 100 keV for the 2n separation energy. We also study the electric dipole excitation of 2n halo nuclei to a continuum state of two neutrons and the core at LO in Halo EFT. We first compare our results with the 11Li data from a Coulomb dissociation experiment and obtain good agreement within the theoretical uncertainty of a LO calculation. We then obtain the low-energy spectrum of B(E1 of this transition at several different values of the 2n separation energy of 22C and the virtual-state energy of 21C. Our predictions can be compared to the outcome of an ongoing experiment on the Coulomb dissociation of 22C to obtain tighter constraints on the two- and three-body energies in the 22C system.
Berger, Edmond L; Gao, Jun; Li, Chong Sheng; Liu, Ze Long; Zhu, Hua Xing
2016-05-27
We present a fully differential next-to-next-to-leading order calculation of charm-quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. The next-to-next-to-leading order corrections in perturbative quantum chromodynamics are found to be comparable in size to the next-to-leading order corrections in certain kinematic regions. We compare our predictions with data on dimuon production in (anti)neutrino scattering from a heavy nucleus. Our results can be used to improve the extraction of the parton distribution function of a strange quark in the nucleon.
Charm-Quark Production in Deep-Inelastic Neutrino Scattering at Next-to-Next-to-Leading Order in QCD
Berger, Edmond L.; Gao, Jun; Li, Chong Sheng; Liu, Ze Long; Zhu, Hua Xing
2016-05-01
We present a fully differential next-to-next-to-leading order calculation of charm-quark production in charged-current deep-inelastic scattering, with full charm-quark mass dependence. The next-to-next-to-leading order corrections in perturbative quantum chromodynamics are found to be comparable in size to the next-to-leading order corrections in certain kinematic regions. We compare our predictions with data on dimuon production in (anti)neutrino scattering from a heavy nucleus. Our results can be used to improve the extraction of the parton distribution function of a strange quark in the nucleon.
On Chiral Space Groups and Chiral Molecules
无
2003-01-01
This note explains the relationship (as well as the absence of a relationship) between chiral space groups and chiral molecules (which have absolute configurations). For a chiral molecule, which must crystallize in a chiral space group, the outcome of the absolute configuration determination must be linked to some other properties of the chiral crystal such as its optical activity for the observation to the relevant.
On Chiral Space Groups and Chiral Molecules
NgSeikWng; HUSheng－Zhi
2003-01-01
This note explains the relationship (as well as the absence of a relationship) between chiral space groups and chiral molecules (which have absolute configurations).For a chiral molecule,which must crystallize in a chiral space group,the outcome of the absolute configuration determination must be linked to some other properties of the chiral crystal such as its optical activity for the observation to the relevant.
Radiative neutron-proton capture in effective chiral lagrangians
Park, T S; Rho, M; Park, Tae Sun; Min, Dong Pil; Rho, Mannque
1994-01-01
We calculate the cross-section for the thermal n+p\\rightarrow d+\\gamma process in chiral perturbation theory to next-to-next-to-leading order using heavy-fermion formalism. The exchange current correction is found to be (4.5\\pm 0.3)~\\% in amplitude and the chiral perturbation at one-loop order gives the cross section \\sigma_{th}^{np}=(334\\pm 2)\\ {\\mbox mb} which is in agreement with the experimental value (334.2\\pm 0.5)\\ {\\mbox mb}. Together with the axial charge transitions, this provides a strong support for the power of chiral Lagrangians for nuclear physics.
A Positive-Weight Next-to-Leading-Order Monte Carlo for e+e- Annihilation to Hadrons
Latunde-Dada, O; Webber, Bryan R; Gieseke, Stefan; Latunde-Dada, Oluseyi; Webber, Bryan
2007-01-01
We apply the positive-weight Monte Carlo method of Nason for simulating QCD processes accurate to Next-To-Leading Order to the case of e+e- annihilation to hadrons. The method entails the generation of the hardest gluon emission first and then subsequently adding a `truncated' shower before the emission. We have interfaced our result to the Herwig++ shower Monte Carlo program and obtained better results than those obtained with Herwig++ at leading order with a matrix element correction.
Cameron, R.P.; Cameron, J. A.; Barnett, S. M.
2016-01-01
We explain that Stegosaurus exhibited exterior chirality and observe that the largest plate in particular of USNM 4394, USNM 4714, DMNS 2818 and NHMUK R36730 appears to have tilted to the right rather than to the left in each case. Several instances in which Stegosaurus specimens have been confused with their distinct, hypothetical mirror-image forms are highlighted. We believe our findings to be consistent with the hypothesis that Stegosaurus's plates acted primarily as display structures. A...
WU Xing-Gang; YU Yao; CHEN Gu; HAN Hua-Yong
2011-01-01
The B-meson decay constant fB is an important component for studying the B-meson decays, which can be studied through QCD sum rules.We make a detailed discussion on fB from two sum rules up to next-to-leading order, i.e.sum rules Ⅰ and Ⅱ, which are derived from the conventional correlator and the correlator with chiral currents respectively.It is found that these two sum rules are consistent with each other.The sum rules Ⅱ involves less non-perturbative condensates as that of sum rules Ⅰ, and in principle, it can be more accurate if we know the dimensionfour gluon condensate well.It is found that fB decreases with the increment of mb, and to compare with the Belle experimental data on fB, both sum rules Ⅰ and Ⅱ prefer smaller pole b-quark mass, mb = 4.68 ± 0.07 GeV.By varying all the input parameters within their reasonable regions and by adding all the uncertainties in quadrature, we obtain fB = 172+23-25 MeV for sum rules Ⅰ and fB = 214+26-34 MeV for sum rules Ⅱ.PACS numbers: 11.55.Hx, 12.38.-t, 13.20.He, 12.38.Lg
Next-to-next-to-leading order contributions to jet photoproduction and determination of αs
Klasen, Michael; Kramer, Gustav; Michael, Markus
2014-04-01
We present the first calculation of inclusive jet photoproduction with approximate next-to-next-to-leading-order contributions, obtained from a unified threshold resummation formalism. The leading coefficients for direct photoproduction are computed analytically. Together with the coefficients pertinent to parton-parton scattering, they are shown to agree with those appearing in our full next-to-leading-order calculations. For hadron-hadron scattering, numerical agreement is found with a previous calculation of jet production at the Tevatron. We show that the direct and resolved approximate next-to-next-to-leading-order contributions considerably improve the description of final ZEUS data on jet photoproduction and that the error on the determination of the strong coupling constant is significantly reduced.
Top quark forward-backward asymmetry in e+ e- annihilation at next-to-next-to-leading order in QCD.
Gao, Jun; Zhu, Hua Xing
2014-12-31
We report on a complete calculation of electroweak production of top-quark pairs in e+ e- annihilation at next-to-next-to-leading order in quantum chromodynamics. Our setup is fully differential in phase space and can be used to calculate any infrared-safe observable. Especially we calculated the next-to-next-to-leading-order corrections to the top-quark forward-backward asymmetry and found sizable effects. Our results show a large reduction of the theoretical uncertainties in predictions of the forward-backward asymmetry, and allow for a precision determination of the top-quark electroweak couplings at future e+ e- colliders.
Top-squark pair production at the LHC: a complete analysis at next-to-leading order
Germer, Jan; Lindert, Jonas M; Mirabella, Edoardo
2014-01-01
We present a complete next-to-leading order study of top-squark pair production at the LHC, including QCD and EW corrections. The calculation is performed within the Minimal Supersymmetric Standard Model and numerical results are presented for parameter regions compatible with the observed Higgs boson. We employ the most recent parton distribution functions including QED corrections and we find corrections to the inclusive stop-pair production cross section up to 25-30 % compared to the leading-order prediction.
Chiral Nanoscience and Nanotechnology
Dibyendu S. Bag
2008-09-01
Full Text Available The paper reviews nanoscale science and technology of chiral molecules/macromolecules-under twosubtopics-chiral nanotechnology and nano-chiral technology. Chiral nanotechnology discusses thenanotechnology, where molecular chirality plays a role in the properties of materials, including molecularswitches, molecular motors, and other molecular devices; chiral supramolecules and self-assembled nanotubesand their functions are also highlighted. Nano-chiral technology describes the nanoscale approaches to chiraltechnology such as asymmetric synthesis and catalysis, chiral separation and detection, and enantiomericanalysis. Chiral sensors have also been included. The state-of-the-art chiral research at DMSRDE,Kanpur isalso presented.Defence Science Journal, 2008, 58(5, pp.626-635, DOI:http://dx.doi.org/10.14429/dsj.58.1685
Next-to-Leading Order Calculation of the Single Transverse Spin Asymmetry in the Drell-Yan Process
Vogelsang, Werner; Yuan, Feng
2009-03-30
We calculate the next-to-leading order perturbative QCD corrections to the transverse momentum weighted single transverse spin asymmetry in Drell-Yan lepton pair production in hadronic collisions. We identify the splitting function relevant for the scale evolution of the twist-three quark-gluon correlation function. We comment on the consequences of our results for phenomenology.
Chiral dynamics and peripheral transverse densities
Granados, Carlos G. [Uppsala University (Sweden); Weiss, Christian [JLAB, Newport News, VA (United States)
2014-01-01
In the partonic (or light-front) description of relativistic systems the electromagnetic form factors are expressed in terms of frame-independent charge and magnetization densities in transverse space. This formulation allows one to identify the chiral components of nucleon structure as the peripheral densities at transverse distances b = O(M{sub {pi}}{sup -1}) and compute them in a parametrically controlled manner. A dispersion relation connects the large-distance behavior of the transverse charge and magnetization densities to the spectral functions of the Dirac and Pauli form factors near the two--pion threshold at timelike t = 4 M{ sub {pi}}{sup 2}, which can be computed in relativistic chiral effective field theory. Using the leading-order approximation we (a) derive the asymptotic behavior (Yukawa tail) of the isovector transverse densities in the "chiral" region b = O(M{sub {pi}}{sup -1}) and the "molecular" region b = O(M{sub N}{sup 2}/M{sub {pi}}{sup 3}); (b) perform the heavy-baryon expansion of the transverse densities; (c) explain the relative magnitude of the peripheral charge and magnetization densities in a simple mechanical picture; (d) include Delta isobar intermediate states and study the peripheral transverse densities in the large-N{ sub c} limit of QCD; (e) quantify the region of transverse distances where the chiral components of the densities are numerically dominant; (f) calculate the chiral divergences of the b{sup 2}-weighted moments of the isovector transverse densities (charge and anomalous magnetic radii) in the limit M{sub {pi}} -> 0 and determine their spatial support. Our approach provides a concise formulation of the spatial structure of the nucleon's chiral component and offers new insights into basic properties of the chiral expansion. It relates the information extracted from low-t elastic form factors to the generalized parton distributions probed in peripheral high-energy scattering processes.
Plum, Eric, E-mail: erp@orc.soton.ac.uk [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Zheludev, Nikolay I., E-mail: niz@orc.soton.ac.uk [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); The Photonics Institute and Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637378 (Singapore)
2015-06-01
Mirrors are used in telescopes, microscopes, photo cameras, lasers, satellite dishes, and everywhere else, where redirection of electromagnetic radiation is required making them arguably the most important optical component. While conventional isotropic mirrors will reflect linear polarizations without change, the handedness of circularly polarized waves is reversed upon reflection. Here, we demonstrate a type of mirror reflecting one circular polarization without changing its handedness, while absorbing the other. The polarization-preserving mirror consists of a planar metasurface with a subwavelength pattern that cannot be superimposed with its mirror image without being lifted out of its plane, and a conventional mirror spaced by a fraction of the wavelength from the metasurface. Such mirrors enable circularly polarized lasers and Fabry-Pérot cavities with enhanced tunability, gyroscopic applications, polarization-sensitive detectors of electromagnetic waves, and can be used to enhance spectroscopies of chiral media.
Two-pion exchange NN potential from Lorentz-invariant $\\chi$EFT
Higa, Renato; Robilotta, Manoel; da Rocha, Carlos A
2006-10-12
We outline the progress made in the past five years by the Sao Paulo group in the development of a two-pion exchange nucleon-nucleon potential within a Lorentz-invariant framework of (baryon) chiral perturbation theory.
Molecular chirality at surfaces
Ernst, Karl-Heinz [Empa, Swiss Federal Laboratories for Materials Science and Technology, Ueberlandstrasse 129, 8600 Duebendorf (Switzerland); Organic Chemistry Institute, University Zurich, 8057 Zuerich (Switzerland)
2012-11-15
With the adsorption of larger molecules being increasingly tackled by surface scientists, the aspect of chirality often plays a role. This paper gives a topical review of molecular chirality at surfaces and gives a phenomenological overview of different aspects of adsorption and self-assembly of chiral and prochiral molecules and the principles of mirror-symmetry breaking at a surface. After a brief introduction into the history of molecular chirality and the important role it played for understanding the spatial structure of molecules, definitions of chirality are presented. Topics treated here are principle ways to create single chiral adsorbates, chiral ensembles, and monolayers by achiral molecules, adsorption of intrinsically chiral molecules at achiral and chiral surfaces, long-range symmetry breaking in two-dimensional (2D) crystals due to additional chiral bias, chiral restructuring of solid surfaces under the influence of chiral molecules, switching the handedness of adsorbates, and chirality at the liquid/air interface. An outlook onto further potential research directions and recommendations for further reading, including nonsurface-related sources of chiral topics completes this paper. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)
Klasen, M
2009-01-01
We perform next-to-leading order calculations of the single-diffractive and non-diffractive cross sections for dijet production in proton-antiproton collisions at the Tevatron. By comparing their ratio to the data published by the CDF collaboration for two different center-of-mass energies, we deduce the rapidity-gap survival probability as a function of the momentum fraction of the parton in the antiproton. Assuming Regge factorization, this probability can be interpreted as a suppression factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the suppression factor in proton-antiproton collisions depends on the momentum fraction of the parton in the Pomeron even at next-to-leading order.
Klasen, Michael; Kramer, Gustav
2009-10-01
We perform next-to-leading order calculations of the single-diffractive and nondiffractive cross sections for dijet production in proton-antiproton collisions at the Tevatron. By comparing their ratio to the data published by the CDF collaboration for two different center-of-mass energies, we deduce the rapidity-gap survival probability as a function of the momentum fraction of the parton in the antiproton. Assuming Regge factorization, this probability can be interpreted as a suppression factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the suppression factor in proton-antiproton collisions depends on the momentum fraction of the parton in the Pomeron even at next-to-leading order.
Klasen, M. [Univ. Joseph Fourier, Laboratoire de Physique Subatomique et de Cosmologie, Grenoble (France); Kramer, G. [Univ. Hamburg, II. Inst. fuer Theoretische Physik (Germany)
2009-08-15
We perform next-to-leading order calculations of the single-diffractive and non-diffractive cross sections for dijet production in proton-antiproton collisions at the Tevatron. By comparing their ratio to the data published by the CDF collaboration for two different center-of-mass energies, we deduce the rapidity-gap survival probability as a function of the momentum fraction of the parton in the antiproton. Assuming Regge factorization, this probability can be interpreted as a suppression factor for the diffractive structure function measured in deep-inelastic scattering at HERA. In contrast to the observations for photoproduction, the suppression factor in protonantiproton collisions depends on the momentum fraction of the parton in the Pomeron even at next-to-leading order. (orig.)
Next-to-leading order unitarity fits in Two-Higgs-Doublet models with soft $\\mathbb{Z}_2$ breaking
Cacchio, Vincenzo; Eberhardt, Otto; Murphy, Christopher W
2016-01-01
We fit the next-to-leading order unitarity conditions to the Two-Higgs-Doublet model with a softly broken $\\mathbb{Z}_2$ symmetry. In doing so, we alleviate the existing uncertainty on how to treat higher order corrections to quartic couplings of its Higgs potential. A simplified approach to implementing the next-to-leading order unitarity conditions is presented. These new bounds are then combined with all other relevant constraints, including the complete set of LHC Run I data. The upper $95\\%$ bounds we find are $4.2$ on the absolute values of the quartic couplings, and $235$ GeV ($100$ GeV) for the mass degeneracies between the heavy Higgs particles in the type I (type II) scenario. In type II, we exclude an unbroken $\\mathbb{Z}_2$ symmetry with a probability of $95\\%$. All fits are performed using the open-source code HEPfit.
Production of massless bottom jets in p anti p and pp collisions at next-to-leading order of QCD
Bierenbaum, Isabella [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Kramer, Gustav [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik
2016-03-15
We present predictions for the inclusive production of bottom jets in proton-antiproton collisions at 1.96 TeV and proton-proton collisions at 7 TeV. The bottom quark is considered massless. In this scheme, we find that at small transverse momentum (p{sub T}) the ratio of the next-to-leading order to the leading-order cross section (K factor) is smaller than one. It increases with increasing p{sub T} and approaches one at larger p{sub T} at a value depending essentially on the choice of the renormalization scale. Adding non-perturbative corrections obtained from PYTHIA Monte Carlo calculations leads to reasonable agreement with experimental b-jet cross sections obtained by the CDF and the CMS collaborations.
Polarized Di-hadron production in lepton-nucleon collisions at the next-to-leading order of QCD
Hendlmeier, Christof
2008-05-15
We compute the next-to-leading order QCD corrections to the spin-dependent cross section for hadron-pair photoproduction. In the first part of the Thesis the calculation is performed using largely analytical methods. We present a detailed phenomenological study of our results focussing on the K-factors and scale dependence of the next-to-leading order cross sections. The second part is dedicated to an alternative approach using Monte-Carlo integration techniques. We present a detailed description how this method works in practice and give phenomenological studies for the photoproduction of two hadrons. This process is relevant for the extraction of the gluon polarization in present and future spin-dependent lepton-nucleon scattering experiments. (orig.)
Kane-Maguire, Leon A P; Wallace, Gordon G
2010-07-01
This critical review describes the preparation and properties of a relatively new class of chiral macromolecules, namely chiral conducting polymers. It focuses in particular on examples based on polypyrrole, polythiophene and polyaniline. They possess remarkable properties, combining not only chirality with electrical conductivity but also the ability to undergo facile redox and pH switching. These unique properties have opened up a range of exciting new potential applications, including as chiral sensors, as novel stationary phases for chiral separations, and as chiral electrodes for electrochemical asymmetric synthesis (153 references).
Transverse parton distribution functions at next-to-next-to-leading order: the quark-to-quark case.
Gehrmann, Thomas; Lübbert, Thomas; Yang, Li Lin
2012-12-14
We present a calculation of the perturbative quark-to-quark transverse parton distribution function at next-to-next-to-leading order based on a gauge invariant operator definition. We demonstrate for the first time that such a definition works beyond the first nontrivial order. We extract from our calculation the coefficient functions relevant for a next-to-next-to-next-to-leading logarithmic Q(T) resummation in a large class of processes at hadron colliders.
Paatelainen, R.; Eskola, K.J. [Department of Physics, P.O.Box 35, FI-40014 University of Jyväskylä (Finland); Helsinki Institute of Physics, P.O.Box 64, FI-00014 University of Helsinki (Finland); Holopainen, H. [Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, D-60438 Frankfurt am Main (Germany); Niemi, H. [Department of Physics, P.O.Box 35, FI-40014 University of Jyväskylä (Finland); Helsinki Institute of Physics, P.O.Box 64, FI-00014 University of Helsinki (Finland); Tuominen, K. [Department of Physics, P.O.Box 64, FI-00014 University of Helsinki (Finland); Helsinki Institute of Physics, P.O.Box 64, FI-00014 University of Helsinki (Finland)
2014-06-15
We calculate initial conditions for the hydrodynamical evolution in ultrarelativistic heavy-ion collisions at the LHC and RHIC in an improved next-to-leading order perturbative QCD + saturation framework. Using viscous relativistic hydrodynamics, we show that we obtain a good simultaneous description of the centrality dependence of charged particle multiplicities, transverse momentum spectra and elliptic flow at the LHC and at RHIC. In particular, we discuss how the temperature dependence of the shear viscosity is constrained by these data.
Hwang, Sungmin
2017-03-01
We present our calculation of the non-relativistic corrections to the heavy quark-antiquark potential up to leading and next-to-leading order (NLO) via the effective string theory (EST). Full systematics of effective field theory (EFT) are discussed in order for including the NLO contribution that arises in the EST. We also show how the number of dimensionful parameters arising from the EST are reduced by the constraints between the Wilson coeffcients from non-relativistic EFTs for QCD.
Herwig++ Monte Carlo At Next-To-Leading Order for e+e- annihilation and lepton pair production
Latunde-Dada, Oluseyi
2007-01-01
This paper describes the MC@NLO method for matching next-to-leading order (NLO) perturbative QCD with the parton shower and hadronization model of the Monte Carlo (MC) event generator tt Herwig++, for e+e- annihilation and Drell-Yan lepton pair production. Details of the event generation method as well as spin, flavour, momentum and colour assignments are presented. We obtain predictions for various distributions which arecompared with experimental data.
Herwig++ Monte Carlo At Next-To-Leading Order for e+e- annihilation and lepton pair production.
Latunde-Dada, Oluseyi
2007-01-01
This paper describes the MC@NLO method for matching next-to-leading order (NLO) perturbative QCD with the parton shower and hadronization model of the Monte Carlo (MC) event generator tt Herwig++, for e+e- annihilation and Drell-Yan lepton pair production. Details of the event generation method as well as spin, flavour, momentum and colour assignments are presented. We obtain predictions for various distributions which arecompared with experimental data.
Iancu, E; Triantafyllopoulos, D N
2016-01-01
Within the Color Glass Condensate effective theory, we reconsider the next-to-leading order (NLO) calculation of the single inclusive particle production at forward rapidities in proton-nucleus collisions at high energy. Focusing on quark production for definiteness, we establish a new factorization scheme, valid thru NLO, in which all the radiative corrections are encoded into a single piece: a NLO impact factor, built with the produced quark and its (not necessarily soft) daughter gluon, which together scatter off the gluon distribution in the nucleus and thus measure its high-energy evolution to next-to-leading order. The NLO impact factor was previously computed in [1,2], but the reorganization of the perturbation theory that we propose is new. The non-linear evolution of the dense nucleus is not known beyond leading order, but we manage to reformulate it as the NLO evolution of the dilute projectile, amended by collinear improvement. As compared to the previous proposal in [1,2], in our factorization sch...
Next-to-leading-order electroweak corrections to the production of four charged leptons at the LHC
Biedermann, Benedikt; Dittmaier, Stefan; Hofer, Lars; Jager, Barbara
2016-01-01
We present a state-of-the-art calculation of the next-to-leading-order electroweak corrections to ZZ production, including the leptonic decays of the Z bosons into $\\mu^+\\mu^-\\mathrm{e}^+\\mathrm{e}^-$ or $\\mu^+\\mu^-\\mu^+\\mu^-$ final states. We use complete leading-order and next-to-leading-order matrix elements for four-lepton production, including contributions of virtual photons and all off-shell effects of Z bosons, where the finite Z-boson width is taken into account using the complex-mass scheme. The matrix elements are implemented into Monte Carlo programs allowing for the evaluation of arbitrary differential distributions. We present integrated and differential cross sections for the LHC at 13 TeV both for an inclusive setup where only lepton identification cuts are applied, and for a setup motivated by Higgs-boson analyses in the four-lepton decay channel. The electroweak corrections are divided into photonic and purely weak contributions. The former show the well-known pronounced tails near kinematic...
Altinoluk, Tolga; Beuf, Guillaume; Kovner, Alex; Lublinsky, Michael
2014-01-01
We reconsider the perturbative next-to-leading calculation of the single inclusive hadron production in the framework of the hybrid formalism, applied to hadron production in proton-nucleus collisions. Our analysis, performed in the wave function approach, differs from the previous works in three points. First, we are careful to specify unambiguously the rapidity interval that has to be included in the evolution of the leading-order eikonal scattering amplitude. This is important, since varying this interval by a number of order unity changes the next-to-leading order correction that the calculation is meant to determine. Second, we introduce the explicit requirement that fast fluctuations in the projectile wave function which only exist for a short time are not resolved by the target. This Ioffe time cutoff also strongly affects the next-to-leading order terms. Third, our result does not employ the approximation of a large number of colors. Our final expressions are unambiguous and do not coincide at next-to...
SIMP model at NNLO in chiral perturbation theory
Hansen, Martin Rasmus Lundquist; Langaeble, K.; Sannino, F.
2015-01-01
We investigate the phenomenological viability of a recently proposed class of composite dark matter models where the relic density is determined by 3 to 2 number-changing processes in the dark sector. Here the pions of the strongly interacting field theory constitute the dark matter particles....... By performing a consistent next-to-leading and next-to-next-to-leading order chiral perturbative investigation we demonstrate that the leading order analysis cannot be used to draw conclusions about the viability of the model. We further show that higher order corrections substantially increase the tension...
Subtraction of power counting breaking terms in chiral perturbation theory: spinless matter fields
Du, Meng-Lin; Meißner, Ulf-G
2016-01-01
When matter fields are included in chiral perturbation theory, the nonvanishing mass in the chiral limit introduces a new energy scale so that the loop diagrams including such matter field propagators spoil the usual power counting. However, the power counting breaking terms can be absorbed into counterterms in the chiral Lagrangian. In this paper, we systematically derive these terms to leading one-loop order (next-to-next-to leading order in the chiral expansion) at once by calculating the generating functional using the path integral. They are then absorbed by counterterms in the next-to-leading order Lagrangian. The method can be extended to calculating power counting breaking terms for other matter fields.
Chiral Gravitational Waves from Chiral Fermions
Anber, Mohamed M
2016-01-01
We report on a new mechanism that leads to the generation of primordial chiral gravitational waves, and hence, the violation of the parity symmetry in the Universe. We show that nonperturbative production of fermions with a definite helicity is accompanied by the generation of chiral gravitational waves. This is a generic and model-independent phenomenon that can occur during inflation, reheating and radiation eras, and can leave imprints in the cosmic microwave background polarization and may be observed in future ground- and space-based interferometers. We also discuss a specific model where chiral gravitational waves are generated via the production of light chiral fermions during pseudoscalar inflation.
Chiral gravitational waves from chiral fermions
Anber, Mohamed M.; Sabancilar, Eray
2017-07-01
We report on a new mechanism that leads to the generation of primordial chiral gravitational waves, and hence, the violation of the parity symmetry in the Universe. We show that nonperturbative production of fermions with a definite helicity is accompanied by the generation of chiral gravitational waves. This is a generic and model-independent phenomenon that can occur during inflation, reheating and radiation eras, and can leave imprints in the cosmic microwave background polarization and may be observed in future ground- and space-based interferometers. We also discuss a specific model where chiral gravitational waves are generated via the production of light chiral fermions during pseudoscalar inflation.
Nonlinear Boundary Dynamics and Chiral Symmetry in Holographic QCD
Albrecht, Dylan; Wilcox, Ronald J
2011-01-01
In the hard-wall model of holographic QCD we find that nonlinear boundary dynamics are required in order to maintain the correct pattern of explicit and spontaneous chiral symmetry breaking beyond leading order in the pion fields. With the help of a field redefinition, we demonstrate that the requisite nonlinear boundary conditions are consistent with the Sturm-Liouville structure required for the Kaluza-Klein decomposition of bulk fields. Observables insensitive to the chiral limit receive only small corrections in the improved description, and classical calculations in the hard-wall model remain surprisingly accurate.
Eta-photoproduction in a gauge-invariant chiral unitary framework
Ruic, Dino; Meissner, Ulf-G
2011-01-01
We analyse photoproduction of eta mesons off the proton in a gauge-invariant chiral unitary framework. The interaction kernel for meson-baryon scattering is derived from the leading order chiral effective Lagrangian and iterated in a Bethe-Salpeter equation. The recent precise threshold data from the Crystal Ball at MAMI can be described rather well and the complex pole corresponding to the S11(1535) is extracted. An extension of the kernel is also discussed.
Li, Hao-Song; Chen, Xiao-Lin; Deng, Wei-Zhen; Zhu, Shi-Lin
2016-01-01
We have systematically investigated the magnetic moments and magnetic form factors of the decuplet baryons to the next-to-next-leading order in the framework of the heavy baryon chiral perturbation theory. Our calculation includes the contributions from both the intermediate decuplet and octet baryon states in the loops. We also calculate the charge and magnetic dipole form factors of the decuplet baryons. Our results may be useful to the chiral extrapolation of the lattice simulations of the decuplet electromagnetic properties.
Salcedo, L.L. [Dept. de Fisica Moderna, Universidad de Granada (Spain)
2001-04-01
Explicit exact formulas are presented, for the leading order term in a strict chiral covariant derivative expansion, for the abnormal parity component of the effective action of two- and four-dimensional Dirac fermions in the presence of scalar, pseudo-scalar, vector and axial vector background fields. The formulas hold for completely general internal symmetry groups and general configurations. In particular, the scalar and pseudo-scalar fields need not be on the chiral circle. (orig.)
Next-to-leading-order electroweak corrections to the production of four charged leptons at the LHC
Biedermann, Benedikt; Denner, Ansgar; Dittmaier, Stefan; Hofer, Lars; Jäger, Barbara
2017-01-01
We present a state-of-the-art calculation of the next-to-leading-order electroweak corrections to ZZ production, including the leptonic decays of the Z bosons into μ + μ -e+e- or μ + μ - μ + μ - final states. We use complete leading-order and next-to-leading-order matrix elements for four-lepton production, including contributions of virtual photons and all off-shell effects of Z bosons, where the finite Z-boson width is taken into account using the complex-mass scheme. The matrix elements are implemented into Monte Carlo programs allowing for the evaluation of arbitrary differential distributions. We present integrated and differential cross sections for the LHC at 13 TeV both for an inclusive setup where only lepton identification cuts are applied, and for a setup motivated by Higgs-boson analyses in the four-lepton decay channel. The electroweak corrections are divided into photonic and purely weak contributions. The former show the well-known pronounced tails near kinematical thresholds and resonances; the latter are generically at the level of ˜ -5% and reach several -10% in the high-energy tails of distributions. Comparing the results for μ + μ -e+e- and μ + μ - μ + μ - final states, we find significant differences mainly in distributions that are sensitive to the μ + μ - pairing in the μ + μ - μ + μ - final state. Differences between μ + μ -e+e- and μ + μ - μ + μ - channels due to interferences of equal-flavour leptons in the final state can reach up to 10% in off-shell-sensitive regions. Contributions induced by incoming photons, i.e. photon-photon and quark-photon channels, are included, but turn out to be phenomenologically unimportant.
Catani, Stefano; Cieri, Leandro; de Florian, Daniel; Ferrera, Giancarlo; Grazzini, Massimiliano
2012-02-17
We consider direct diphoton production in hadron collisions, and we compute the next-to-next-to-leading order QCD radiative corrections at the fully differential level. Our calculation uses the q(T) subtraction formalism, and it is implemented in a parton-level Monte Carlo program. The program allows the user to apply arbitrary kinematical cuts on the final-state photons and the associated jet activity and to compute the corresponding distributions in the form of bin histograms. We present selected numerical results related to Higgs boson searches at the LHC and corresponding results at the Tevatron.
Four-Jet Production at the Large Hadron Collider at Next-to-Leading Order in QCD
Bern, Z; Dixon, L J; Cordero, F Febres; Hoeche, S; Kosower, D A; Ita, H; Maitre, D; Ozeren, K
2012-01-01
We present the cross sections for production of up to four jets at the Large Hadron Collider, at next-to-leading order in the QCD coupling. We use the BlackHat library in conjunction with SHERPA and a recently developed algorithm for assembling primitive amplitudes into color-dressed amplitudes. We adopt the cuts used by ATLAS in their study of multi-jet events in pp collisions at \\sqrt{s} = 7 TeV. We include estimates of nonperturbative corrections and compare to ATLAS data. We store intermediate results in a framework that allows the inexpensive computation of additional results for different choices of scale or parton distributions.
Hwang Sungmin
2017-01-01
Full Text Available We present our calculation of the non-relativistic corrections to the heavy quark-antiquark potential up to leading and next-to-leading order (NLO via the effective string theory (EST. Full systematics of effective field theory (EFT are discussed in order for including the NLO contribution that arises in the EST. We also show how the number of dimensionful parameters arising from the EST are reduced by the constraints between the Wilson coeffcients from non-relativistic EFTs for QCD.
Next-to-Next-to Leading Order QCD Predictions for Single Jet Inclusive Production at the LHC
Currie, J.; Glover, E. W. N.; Pires, J.
2017-02-01
We report the first calculation of fully differential jet production at leading color in all partonic channels at next-to-next-to leading order in perturbative QCD and compare to the available ATLAS 7 TeV data. We discuss the size and shape of the perturbative corrections along with their associated scale variation across a wide range in jet transverse momentum, pT, and rapidity, y . We find significant effects, especially at low pT, and discuss the possible implications for parton distribution function fits.
Dai, Lingyun [Indiana University , Bloomington, IN; Prokudin, Alexei [Jefferson Lab, Newport News, VA; Kang, Zhong-Bo [Los Alamos National Laboratory, Los Alamos, NM 87545; Vitev, Ivan [Los Alamos National Laboratory, Los Alamos
2015-09-01
We study the three-gluon correlation function contribution to the Sivers asymmetry in semi-inclusive deep inelastic scattering. We first establish the matching between the usual twist-3 collinear factorization approach and transverse momentum dependent factorization formalism for the moderate transverse momentum region. We then derive the so-called coefficient functions used in the usual TMD evolution formalism. Finally, we perform the next-to-leading order calculation for the transverse-momentum-weighted spin-dependent differential cross section, from which we identify the QCD collinear evolution of the twist-3 Qiu-Sterman function: the off-diagonal contribution from the three-gluon correlation functions.
The radiative return at phi- and B-factories: FSR for muon pair production at next-to-leading order
Czyz, Henryk; Kuhn, Johann H; Rodrigo, Germán; Czyz, Henryk; Grzelinska, Agnieszka; Kuhn, Johann H.; Rodrigo, German
2005-01-01
Muon pair production through the radiative return is of importance for a measurement of the hadronic production cross section in two ways: it provides an independent calibration and it may give rise to an important background for a measurement of the pion form factor. With this motivation the Monte Carlo event generator PHOKHARA is extended to include next-to-leading order radiative corrections to the reaction $e^+e^-\\to \\mu^+\\mu^-\\gamma$. Furthermore, virtual ISR corrections to FSR from pions are introduced, which extends the applicability of the generator into a new kinematical regime. Finally, the effect of photon vacuum polarization is introduced into this new version of the generator.
Höche, Stefan; Schönherr, Marek
2012-11-01
We quantify uncertainties in the Monte Carlo simulation of inclusive and dijet final states, which arise from using the MC@NLO technique for matching next-to-leading order parton-level calculations and parton showers. We analyse a large variety of data from early measurements at the LHC. In regions of phase space where Sudakov logarithms dominate over high-energy effects, we observe that the main uncertainty can be ascribed to the free parameters of the parton shower. In complementary regions, the main uncertainty stems from the considerable freedom in the simulation of underlying events.
Top-quark pair production at next-to-next-to-leading order QCD in electron positron collisions
Chen, Long; Heisler, Dennis; Bernreuther, Werner; Si, Zong-Guo
2016-01-01
We set up a formalism, within the antenna subtraction framework, for computing the production of a massive quark-antiquark pair in electron positron collisions at next-to-next-to-leading order in the coupling $\\alpha_s$ of quantum chromodynamics at the differential level. Our formalism applies to the calculation of any infrared-safe observable. We apply this set-up to the production of top-quark top antiquark pairs in the continuum. We compute the production cross section and several distributions. We determine, in particular, the top-quark forward-backward asymmetry at order $\\alpha_s^2$. Our result agrees with previous computations of this observable.
Liu, Keh-Fei
2016-01-01
The relevance of chiral symmetry in baryons is highlighted in three examples in the nucleon spectroscopy and structure. The first one is the importance of chiral dynamics in understanding the Roper resonance. The second one is the role of chiral symmetry in the lattice calculation of $\\pi N \\sigma$ term and strangeness. The third one is the role of chiral $U(1)$ anomaly in the anomalous Ward identity in evaluating the quark spin and the quark orbital angular momentum. Finally, the chiral effective theory for baryons is discussed.
QCD next-to-leading order predictions matched to parton showers for vector-like quark models
Fuks, Benjamin
2016-01-01
Vector-like quarks are featured by a wealth of beyond the Standard Model theories and are consequently an important goal of many LHC searches for new physics. Those searches, as well as most related phenomenological studies, however rely on predictions evaluated at the leading-order accuracy in QCD and consider well-defined simplified benchmark scenarios. Adopting an effective bottom-up approach, we compute next-to-leading-order predictions for vector-like-quark pair-production and single production in association with jets, with a weak or with a Higgs boson in a general new physics setup. We additionally compute vector-like-quark contributions to the production of a pair of Standard Model bosons at the same level of accuracy. For all processes under consideration, we focus both on total cross sections and on differential distributions, most these calculations being performed for the first time in our field. As a result, our work paves the way to precise extraction of experimental limits on vector-like quarks...
QCD next-to-leading order predictions matched to parton showers for vector-like quark models
Fuks, Benjamin
2017-02-27
Vector-like quarks are featured by a wealth of beyond the Standard Model theories and are consequently an important goal of many LHC searches for new physics. Those searches, as well as most related phenomenological studies, however rely on predictions evaluated at the leading-order accuracy in QCD and consider well-defined simplified benchmark scenarios. Adopting an effective bottom-up approach, we compute next-to-leading-order predictions for vector-like-quark pair-production and single production in association with jets, with a weak or with a Higgs boson in a general new physics setup. We additionally compute vector-like-quark contributions to the production of a pair of Standard Model bosons at the same level of accuracy. For all processes under consideration, we focus both on total cross sections and on differential distributions, most these calculations being performed for the first time in our field. As a result, our work paves the way to precise extraction of experimental limits on vector-like quarks...
Czakon, Michal; Fiedler, Paul; Mitov, Alexander
2015-07-31
We determine the dominant missing standard model (SM) contribution to the top quark pair forward-backward asymmetry at the Tevatron. Contrary to past expectations, we find a large, around 27%, shift relative to the well-known value of the inclusive asymmetry in next-to-leading order QCD. Combining all known standard model corrections, we find that A(FB)(SM)=0.095±0.007. This value is in agreement with the latest DØ measurement [V. M. Abazov et al. (D0 Collaboration), Phys. Rev. D 90, 072011 (2014)] A(FB)(D∅)=0.106±0.03 and about 1.5σ below that of CDF [T. Aaltonen et al. (CDF Collaboration), Phys. Rev. D 87, 092002 (2013)] A(FB)(CDF)=0.164±0.047. Our result is derived from a fully differential calculation of the next-to-next-to leading order (NNLO) QCD corrections to inclusive top pair production at hadron colliders and includes-without any approximation-all partonic channels contributing to this process. This is the first complete fully differential calculation in NNLO QCD of a two-to-two scattering process with all colored partons.
QCD next-to-leading-order predictions matched to parton showers for vector-like quark models.
Fuks, Benjamin; Shao, Hua-Sheng
2017-01-01
Vector-like quarks are featured by a wealth of beyond the Standard Model theories and are consequently an important goal of many LHC searches for new physics. Those searches, as well as most related phenomenological studies, however, rely on predictions evaluated at the leading-order accuracy in QCD and consider well-defined simplified benchmark scenarios. Adopting an effective bottom-up approach, we compute next-to-leading-order predictions for vector-like-quark pair production and single production in association with jets, with a weak or with a Higgs boson in a general new physics setup. We additionally compute vector-like-quark contributions to the production of a pair of Standard Model bosons at the same level of accuracy. For all processes under consideration, we focus both on total cross sections and on differential distributions, most these calculations being performed for the first time in our field. As a result, our work paves the way to precise extraction of experimental limits on vector-like quarks thanks to an accurate control of the shapes of the relevant observables and emphasise the extra handles that could be provided by novel vector-like-quark probes never envisaged so far.
Cavero-Pelaez, Ines; Parashar, Prachi; Shajesh, K V
2008-01-01
We calculate the lateral Casimir force between corrugated parallel plates, described by $\\delta$-function potentials, interacting through a scalar field, using the multiple scattering formalism. The contributions to the Casimir energy due to uncorrugated parallel plates is treated as a background from the outset. We derive the leading- and next-to-leading-order contribution to the lateral Casimir force for the case when the corrugation amplitudes are small in comparison to corrugation wavelengths. We present explicit results in terms of finite integrals for the case of the Dirichlet limit, and exact results for the weak-coupling limit, for the leading- and next-to-leading-orders. The correction due to the next-to-leading contribution is significant. In the weak coupling limit we calculate the lateral Casimir force exactly in terms of a single integral which we evaluate numerically. Exact results for the case of the weak limit allows us to estimate the error in the perturbative results. We show that the error ...
$ZZW$ production at the LHC within large extra dimensions model in next-to-leading order QCD
Chong, Chen; Wen-Gan, Ma; Ren-You, Zhang; Xiao-Zhou, Li; Yu, Zhang
2014-01-01
We investigate the large extra dimensions (LED) effects induced by the Kaluza-Klein gravitons up to the QCD next-to-leading order (NLO) on the $ZZW$ production at the large hardron collider (LHC). The integrated cross sections and some kinematic distributions are presented in both the standard model (SM) and the LED model. Our results show that the leading order (LO) relative deviations between the predictions in the LED model and the SM are significant, especially in the large $M_{ZZ}$ region, large $p_T$ and the central rapidity regions of the final products separately, while the NLO QCD corrections remarkably reduce the relative LED deviations. We find that if we take $M_S=4.8~{\\rm TeV}$, $d=3$, and adopt the event selection scheme with $M_{ZZ}>500~{\\rm GeV}$, $p_T^{Z}>100~{\\rm GeV}$ and $p_T^{W}>20~{\\rm GeV}$, the LO (NLO) relative deviations at the $14~{\\rm TeV}$ LHC increase to $19.8 \\%$ ($8.05\\%$) and $12.30\\%$ ($5.63\\%$) for the $ZZW^+$ and $ZZW^-$ productions, respectively. We also see that with the ...
Chiral Rotational Spectroscopy
Cameron, Robert P; Barnett, Stephen M
2015-01-01
We introduce chiral rotational spectroscopy: a new technique that enables the determination of the individual optical activity polarisability components $G_{XX}'$, $G_{YY}'$, $G_{ZZ}'$, $A_{X,YZ}$, $A_{Y,ZX}$ and $A_{Z,XY}$ of chiral molecules, in a manner that reveals the enantiomeric constitution of a sample whilst yielding an incisive signal even for a racemate. Chiral rotational spectroscopy could find particular use in the analysis of molecules that are chiral by virtue of their isotopic constitution and molecules with multiple chiral centres. The principles that underpin chiral rotational spectroscopy can also be exploited in the search for molecular chirality in space, which, if found, may add weight to hypotheses that biological homochirality and indeed life itself are of cosmic origin.
Charm quark contribution to K+ ---> pi+ nu anti-nu at next-to-next-to-leading order
Buras, Andrzej J.; /Munich, Tech. U.; Gorbahn, Martin; /Durham U., IPPP /Karlsruhe U., TTP; Haisch, Ulrich; /Fermilab /Zurich U.; Nierste, Ulrich; /Karlsruhe U., TTP
2006-03-01
The authors calculate the complete next-to-next-to-leading order QCD corrections to the charm contribution of the rare decay K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}. They encounter several new features, which were absent in lower orders. They discuss them in detail and present the results for the two-loop matching conditions of the Wilson coefficients, the three-loop anomalous dimensions, and the two-loop matrix elements of the relevant operators that enter the next-to-next-to-leading order renormalization group analysis of the Z-penguin and the electroweak box contribution. The inclusion of the next-to-next-to-leading order QCD corrections leads to a significant reduction of the theoretical uncertainty from {+-} 9.8% down to {+-} 2.4% in the relevant parameter P{sub c}(X), implying the leftover scale uncertainties in {Beta}(K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}) and in the determination of |V{sub td}|, sin 2{beta}, and {gamma} from the K {yields} {pi}{nu}{bar {nu}} system to be {+-} 1.3%, {+-} 1.0%, {+-} 0.006, and {+-} 1.2{sup o}, respectively. For the charm quark {ovr MS} mass m{sub c}(m{sub c}) = (1.30 {+-} 0.05) GeV and |V{sub us}| = 0.2248 the next-to-leading order value P{sub c}(X) = 0.37 {+-} 0.06 is modified to P{sub c}(X) = 0.38 {+-} 0.04 at the next-to-next-to-leading order level with the latter error fully dominated by the uncertainty in m{sub c}(m{sub c}). They present tables for P{sub c}(X) as a function of m{sub c}(m{sub c}) and {alpha}{sub s}(M{sub z}) and a very accurate analytic formula that summarizes these two dependences as well as the dominant theoretical uncertainties. Adding the recently calculated long-distance contributions they find {Beta}(K{sup +} {yields} {pi}{sup +}{nu}{bar {nu}}) = (8.0 {+-} 1.1) x 10{sup -11} with the present uncertainties in m{sub c}(m{sub c}) and the Cabibbo-Kobayashi-Maskawa elements being the dominant individual sources in the quoted error. They also emphasize that improved calculations of the long
On chiral and non chiral 1D supermultiplets
Toppan, Francesco, E-mail: toppan@cbpf.b [Centro Brasileiro de Pesquisas Fisicas (TEO/CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Fisica Teorica
2011-07-01
In this talk I discuss and clarify some issues concerning chiral and non chiral properties of the one-dimensional supermultiplets of the N-extended supersymmetry. Quaternionic chirality can be defined for N = 4, 5, 6, 7, 8. Octonionic chirality for N = 8 and beyond. Inequivalent chiralities only arise when considering several copies of N = 4 or N = 8 supermultiplets. (author)
Chiral symmetry and chiral-symmetry breaking
Peskin, M.E.
1982-12-01
These lectures concern the dynamics of fermions in strong interaction with gauge fields. Systems of fermions coupled by gauge forces have a very rich structure of global symmetries, which are called chiral symmetries. These lectures will focus on the realization of chiral symmetries and the causes and consequences of thier spontaneous breaking. A brief introduction to the basic formalism and concepts of chiral symmetry breaking is given, then some explicit calculations of chiral symmetry breaking in gauge theories are given, treating first parity-invariant and then chiral models. These calculations are meant to be illustrative rather than accurate; they make use of unjustified mathematical approximations which serve to make the physics more clear. Some formal constraints on chiral symmetry breaking are discussed which illuminate and extend the results of our more explicit analysis. Finally, a brief review of the phenomenological theory of chiral symmetry breaking is presented, and some applications of this theory to problems in weak-interaction physics are discussed. (WHK)
Extrinsic electromagnetic chirality in metamaterials
Plum, E.; Fedotov, V. A.; Zheludev, N. I.
2009-01-01
Three- and two-dimensional chirality arising from the mutual orientation of non-chiral planar metamaterial structures and the incident electromagnetic wave (extrinsic chirality) lead to pronounced optical activity, circular dichroism and asymmetric transmission indistinguishable from those seen in media consisting of three- and two-dimensionally chiral molecules (intrinsic chirality).
Evidence for chiral logarithms in the baryon spectrum
Walker-Loud, Andre
2011-01-01
Using precise lattice QCD computations of the baryon spectrum, we present the first direct evidence for the presence of contributions to the baryon masses which are non-analytic in the light quark masses; contributions which are often denoted "chiral logarithms". We isolate the poor convergence of SU(3) baryon chiral perturbation theory to the flavor-singlet mass combination. The flavor-octet baryon mass splittings, which are corrected by chiral logarithms at next to leading order in SU(3) chiral perturbation theory, yield baryon-pion axial coupling constants D, F, C and H consistent with QCD values; the first evidence of chiral logarithms in the baryon spectrum. The Gell-Mann--Okubo relation, a flavor-27 baryon mass splitting, which is dominated by chiral corrections from light quark masses, provides further evidence for the presence of non-analytic light quark mass dependence in the baryon spectrum; we simultaneously find the GMO relation to be inconsistent with the first few terms in a taylor expansion in ...
Gelation induced supramolecular chirality: chirality transfer, amplification and application.
Duan, Pengfei; Cao, Hai; Zhang, Li; Liu, Minghua
2014-08-14
Supramolecular chirality defines chirality at the supramolecular level, and is generated from the spatial arrangement of component molecules assembling through non-covalent interactions such as hydrogen bonding, van der Waals interactions, π-π stacking, hydrophobic interactions and so on. During the formation of low molecular weight gels (LMWGs), one kind of fascinating soft material, one frequently encounters the phenomenon of chirality as well as chiral nanostructures, either from chiral gelators or even achiral gelators. A view of gelation-induced supramolecular chirality will be very helpful to understand the self-assembly process of the gelator molecules as well as the chiral structures, the regulation of the chirality in the gels and the development of the "smart" chiral materials such as chiroptical devices, catalysts and chiral sensors. It necessitates fundamental understanding of chirality transfer and amplification in these supramolecular systems. In this review, recent progress in gelation-induced supramolecular chirality is discussed.
Borowka, S; Greiner, N; Heinrich, G; Jones, S P; Kerner, M; Schlenk, J; Schubert, U; Zirke, T
2016-07-01
We present the calculation of the cross section and invariant mass distribution for Higgs boson pair production in gluon fusion at next-to-leading order (NLO) in QCD. Top-quark masses are fully taken into account throughout the calculation. The virtual two-loop amplitude has been generated using an extension of the program GoSam supplemented with an interface to Reduze for the integral reduction. The occurring integrals have been calculated numerically using the program SecDec. Our results, including the full top-quark mass dependence for the first time, allow us to assess the validity of various approximations proposed in the literature, which we also recalculate. We find substantial deviations between the NLO result and the different approximations, which emphasizes the importance of including the full top-quark mass dependence at NLO.
Scalar field correlator in de Sitter space at next-to-leading order in a 1/N-expansion
Gautier, Florian
2015-01-01
We study the dynamics of light quantum scalar fields in de Sitter space on superhorizon scales. We compute the self-energy of an O(N) symmetric theory at next-to-leading order in a 1/N-expansion in the regime of superhorizon momenta and we obtain an exact analytical solution of the corresponding Dyson-Schwinger equations for the two-point correlator. This amounts to resumming the infinite series of nonlocal self-energy insertions, which typically generate spurious infrared and/or secular divergences. The potentially large de Sitter logarithms resum into well-behaved power laws from which we extract the field strength and mass renormalization. The nonperturbative 1/N-expansion allows us to discuss the case of vanishing and negative tree-level square mass, which both correspond to strongly coupled effective theories in the infrared.
Dark matter pair associated with a $W$ boson production at the LHC in next-to-leading order QCD
Mao, Song; Wen-Gan, Ma; Ren-You, Zhang; Jian-You, Guo
2014-01-01
We investigate the QCD next-to-leading order (NLO) corrections to the production of a pair of fermionic dark matter particles associated with a W boson production through a mediator which couples to standard model particles via either a vector or axial-vector coupling at the LHC. We find that the QCD NLO corrections reduce the dependence of the total cross sections on the factorization and renormalization scales, and the $K$-factors increase with the increment of the dark matter mass. We also provide the LO and QCD NLO corrected distributions of the transverse momenta $p_T^\\mu$ of final muon and transverse mass $M_T$. We find that the LO cross section is significantly changed by the QCD NLO corrections.
Next-to-leading order predictions for Z gamma+jet and Z gamma gamma final states at the LHC
Campbell, John M.; Hartanto, Heribertus B.; Williams, Ciaran
2012-11-01
We present next-to-leading order predictions for final states containing leptons produced through the decay of a Z boson in association with either a photon and a jet, or a pair of photons. The effect of photon radiation from the final state leptons is included and we also allow for contributions arising from fragmentation processes. Phenomenological studies are presented for the LHC in the case of final states containing charged leptons and in the case of neutrinos. We also use the procedure introduced by Stewart and Tackmann to provide a reliable estimate of the scale uncertainty inherent in our theoretical calculations of jet-binned Z gamma cross sections. These computations have been implemented in the public code MCFM.
Leading order determination of the gluon polarisation from DIS events with high-$p_T$ hadron pairs
Adolph, C; Alexakhin, V Yu; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Antonov, A A; Austregesilo, A; Badelek, B; Balestra, F; Barth, J; Baum, G; Bedfer, Y; Bernhard, J; Bertini, R; Bettinelli, M; Bicker, K; Bieling, J; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Braun, C; Bravar, A; Bressan, A; Burtin, E; Chaberny, D; Chiosso, M; Chung, S U; Cicuttin, A; Crespo, M L; Dalla Torre, S; Das, S; Dasgupta, S S; Denisov, O.Yu; Dhara, L; Donskov, S V; Doshita, N; Duic, V; Dunnweber, W; Dziewiecki, M; Efremov, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; jr., M.Finger; Fischer, H; Franco, C; von Hohenesche, N.du Fresne; Friedrich, J M; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gazda, R; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmuller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Guthorl, T; Haas, F; von Harrach, D; Hedicke, S; Heinsius, F H; Herrmann, F; Hess, C; Hinterberger, F; Horikawa, N; Hoppner, Ch; d'Hose, N; Huber, S; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Iwata, T; Jahn, R; Jasinski, P; Joosten, R; Kabuss, E; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu.A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, J H; Kolosov, V N; Kondo, K; Konigsmann, K; Konorov, I; Konstantinov, V F; Korzenev, A; Kotzinian, A M; Kouznetsov, O; Kramer, M; Kroumchtein, Z V; Kunne, F.; Kurek, K; Lauser, L; Le Goff, J M; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Maggiora, A; Magnon, A; Makke, N; Mallot, G K; Mann, A; Marchand, C; Martin, A; Marzec, J; Matsuda, T; Meyer, W; Michigami, T; Mikhailov, Yu.V; Moinester, M A; Morreale, A; Mutter, A; Nagaytsev, A; Nagel, T; Nassalski, J P; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Nowak, W D; Nunes, A S; Olshevsky, A G; Ostrick, M; Padee, A; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S.; Perevalova, E; Pesaro, G; Peshekhonov, D V; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pontecorvo, G; Pretz, J; Procureur, S L; Quaresma, M; Quintans, C; Rajotte, J F; Ramos, S; Rapatsky, V; Reicherz, G; Richter, A; Rocco, E; Rondio, E; Rossiyskaya, N S; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Sapozhnikov, M G; Sarkar, S.; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C.; Schluter, T; Schmidt, K; Schmitt, L; Schonning, K; Schopferer, S; Schott, M; Shevchenko, O.Yu; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Stolarski, M; Sulc, M; Sulej, R; Sznajder, P; Takekawa, S; Wolbeek, J.Ter; Tessaro, S; Tessarotto, F; Tkatchev, L G; Uhl, S; Uman, I; Vandenbroucke, M; Virius, M; Vlassov, N V; Wang, L; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zhuravlev, N; Zvyagin, A
2013-01-01
We present a determination of the gluon polarisation Delta g/g in the nucleon, based on the longitudinal double-spin asymmetry of DIS events with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam scattering off a polarised ^6LiD target. The gluon polarisation is evaluated by a Neural Network approach for three intervals of the gluon momentum fraction x_g covering the range 0.04 < x_g < 0.27. The values obtained at leading order in QCD do not show any significant dependence on x_g. Their average is Delta g/g = 0.125 +/- 0.060 (stat.) +/- 0.063 (syst.) at x_g=0.09 and a scale of mu^2 = 3~(GeV/c)^2.
W+W-+3 -jet production at the Large Hadron Collider in next-to-leading-order QCD
Febres Cordero, F.; Hofmann, P.; Ita, H.
2017-02-01
We present next-to-leading-order (NLO) QCD predictions to W+W- production in association with up to three jets at hadron colliders. We include contributions from couplings of the W bosons to light quarks as well as trilinear vector couplings. These processes are used in vector-boson coupling measurements, are background to Higgs signals and are needed to constrain many new physics scenarios. For the first time NLO QCD predictions are shown for electroweak di-vector boson production with three jets at a hadron collider. We show total and differential cross sections for the LHC with proton center-of-mass energies of 8 and 13 TeV. To perform the calculation we employ on-shell and unitarity methods implemented in the blackhat library along with the sherpa package. We have produced event files that can be accessed for future dedicated studies.
J/{psi} plus prompt-photon associated production in two-photon collisions at next-to-leading order
Klasen, M. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik]|[Grenoble Univ., 38 (France). Lab. de Physique Subatomique et de Cosmologie; Kniehl, B.A.; Mihaila, L.N.; Steinhauser, M. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik
2004-08-01
We calculate the cross section of J/{psi} plus prompt-photon inclusive production in {gamma}{gamma} collisions at next-to-leading order within the factorization formalism of nonrelativistic quantum chromodynamics (NRQCD) focusing on direct photoproduction. Apart from direct J/{psi} production, we also include the feed-down from directly-produced {chi}{sub cJ} and {psi}' mesons. We discuss the analytical calculation, in particular the treatment of the various types of singularities and the NRQCD operator renormalization, in some detail. We present theoretical predictions for the future e{sup +}e{sup -} linear collider TESLA, taking into account both Brems- and beamstrahlung. (orig.)
Guzey, V
2016-01-01
We calculate the cross section of diffractive dijet photoproduction in $ep$ scattering at next-to-leading order (NLO) of perturbative QCD (pQCD), which we supplement by a model of factorization breaking for the resolved-photon contribution. In this model, the suppression depends on the flavor and momentum fraction of the partons in the photon. We show that within experimental and theoretical uncertainties, the resulting approach provides a good description of the available HERA data in most of the bins. Hence, taken together with the observation that NLO pQCD explains well the data on diffractive photoproduction of open charm in $ep$ scattering, our model of factorization breaking presents a viable alternative to the scheme based on the global suppression factor.
J/{psi} plus jet associated production in two-photon collisions at next-to-leading order
Klasen, M. [Universite Grenoble I, Laboratoire de Physique Subatomique et de Cosmologie, 53 Avenue des Martyrs, 38026 Grenoble (France); Kniehl, B.A. [II. Institut fuer Theoretische Physik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)]. E-mail: bernd.kniehl@desy.de; Mihaila, L.N. [II. Institut fuer Theoretische Physik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany); Steinhauser, M. [II. Institut fuer Theoretische Physik, Universitaet Hamburg, Luruper Chaussee 149, 22761 Hamburg (Germany)
2005-05-02
We calculate the cross section of J/{psi} plus jet inclusive production in {gamma}{gamma} collisions at next-to-leading order within the factorization formalism of non-relativistic quantum chromodynamics (NRQCD) focusing on direct photoproduction. Apart from direct J/{psi} production, we also include the feed-down from directly-produced {chi}{sub cJ} and {psi}{sup '} mesons. We discuss the analytical calculation, in particular, the treatment of the various types of singularities and the NRQCD operator renormalization, in some detail. We present theoretical predictions for the future e{sup +}e{sup -} linear collider TESLA, taking into account both brems- and beamstrahlung.
Guzey, V. [Petersburg Nuclear Physics Institute (PNPI), National Research Center ' ' Kurchatov Institute' ' , Gatchina (Russian Federation); Klasen, M. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Theoretische Physik, Muenster (Germany)
2016-08-15
We calculate the cross section of diffractive dijet photoproduction in ep scattering at next-to-leading order (NLO) of perturbative QCD (pQCD), which we supplement by a model of factorization breaking for the resolved-photon contribution. In this model, the suppression depends on the flavor and momentum fraction of the partons in the photon. We show that within experimental and theoretical uncertainties, the resulting approach provides a good description of the available HERA data in most of the bins. Hence, taken together with the observation that NLO pQCD explains well the data on diffractive photoproduction of open charm in ep scattering, our model of factorization breaking presents a viable alternative to the scheme based on the global suppression factor. (orig.)
J/{psi} plus jet associated production in two-photon collisions at next-to-leading order
Klasen, M. [Grenoble 1 Univ. (France). Lab. de Physique Subatomique et de Cosmologie; Kniehl, B.A.; Mihaila, L.N.; Steinhauser, M. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik
2004-06-01
We calculate the cross section of J/{psi} plus jet inclusive production in {gamma}{gamma} collisions at next-to-leading order within the factorization formalism of nonrelativistic quantum chromodynamics (NRQCD) focusing on direct photoproduction. Apart from direct J/{psi} production, we also include the feed-down from directly-produced X{sub cJ} and {psi}{sup '} mesons. We discuss the analytical calculation, in particular the treatment of the various types of singularities and the NRQCD operator renormalization, in some detail. We present theoretical predictions for the future e{sup +}e{sup -} linear collider TESLA, taking into account both brems- and beamstrahlung. (orig.)
Guzey, V.; Klasen, M.
2016-08-01
We calculate the cross section of diffractive dijet photoproduction in ep scattering at next-to-leading order (NLO) of perturbative QCD (pQCD), which we supplement by a model of factorization breaking for the resolved-photon contribution. In this model, the suppression depends on the flavor and momentum fraction of the partons in the photon. We show that within experimental and theoretical uncertainties, the resulting approach provides a good description of the available HERA data in most of the bins. Hence, taken together with the observation that NLO pQCD explains well the data on diffractive photoproduction of open charm in ep scattering, our model of factorization breaking presents a viable alternative to the scheme based on the global suppression factor.
Benic, Sanjin; Garcia-Montero, Oscar; Venugopalan, Raju
2016-01-01
We compute the cross section for photons emitted from sea quarks in proton-nucleus collisions at collider energies. The computation is performed within the dilute-dense kinematics of the Color Glass Condensate (CGC) effective field theory. Albeit the result obtained is formally at next-to-leading order in the CGC power counting, it provides the dominant contribution for central rapidities. We observe that the inclusive photon cross section is proportional to all-twist Wilson line correlators in the nucleus. These correlators also appear in quark-pair production; unlike the latter, photon production is insensitive to hadronization uncertainties and therefore more sensitive to multi-parton correlations in the gluon saturation regime of QCD. We demonstrate that $k_\\perp$ and collinear factorized expressions for inclusive photon production are obtained as leading twist approximations to our result. In particular, the collinearly factorized expression is directly sensitive to the nuclear gluon distribution at smal...
Echevarria, Miguel G; Vladimirov, Alexey
2016-01-01
The transverse momentum dependent parton distribution/fragmentation functions (TMDs) are essential in the factorization of a number of processes like Drell-Yan scattering, vector boson production, semi-inclusive deep inelastic scattering, etc. We provide a comprehensive study of unpolarized TMDs at next-to-next-to-leading order, which includes an explicit calculation of these TMDs and an extraction of their matching coefficients onto their integrated analogues, for all flavor combinations. The obtained matching coefficients are important for any kind of phenomenology involving TMDs. In the present study each individual TMD is calculated without any reference to a specific process. We recover the known results for parton distribution functions and provide new results for the fragmentation functions. The results for the gluon transverse momentum dependent fragmentation functions are presented for the first time at one and two loops. We also discuss the structure of singularities of TMD operators and TMD matrix ...
Next-to-leading order predictions for Z gamma+jet and Z gamma gamma final states at the LHC
Campbell, John M; Williams, Ciaran
2012-01-01
We present next-to-leading order predictions for final states containing leptons produced through the decay of a Z boson in association with either a photon and a jet, or a pair of photons. The effect of photon radiation from the final state leptons is included and we also allow for contributions arising from fragmentation processes. Phenomenological studies are presented for the LHC in the case of final states containing charged leptons and in the case of neutrinos. We also use the procedure introduced by Stewart and Tackmann to provide a reliable estimate of the scale uncertainty inherent in our theoretical calculations of jet-binned Z gamma cross sections. These computations have been implemented in the public code MCFM.
Paukkunen, Hannu
2009-06-01
This is the introductory part of my PhD thesis which consists of two parts, the separate introduction and four published articles. The introduction begins by a technically detailed description of the DGLAP evolution and the fast numerical solving method for the DGLAP equations, which has been used in the numerical works of the published articles of this thesis. A write-up of the next-to-leading order (NLO) calculations for the deeply inelastic scattering (DIS) and the Drell-Yan (DY) dilepton production cross-sections is also included. The formalism of the inclusive single hadron production at NLO is described as well, although less rigorously. The introductory part ends with a discussion of the global QCD analyses in general, with a special attention paid to the major work of this thesis, the NLO analysis of nuclear parton densities and their uncertainties.
Next-to-leading order QCD corrections to paired $B_c$ production in $e^+e^-$ annihilation
Berezhnoy, A V; Onishchenko, A I; Poslavsky, S V
2016-01-01
We present theoretical analysis of paired $B_c$ mesons production in $e^+e^-$ annihilation at different energy scales taking into account full next-to-leading order QCD corrections. Both possible electroweak channels are considered: production via virtual photon and via virtual $Z$-boson. We study in detail the role of radiative QCD corrections, which were found to be significant especially at low energies. It is shown that the contribution from $Z$-boson is significant at high energies ($\\sqrt{s} > M_Z/2$) especially in the case of paired production of pseudo-scalar and vector ($B_c + B_c^*$) mesons. Azimuthal asymmetry induced by a $P$-violating weak interaction with $Z$-boson is also analyzed.
Chiral lagrangian approach to exchange vector currents in nuclei
Park, T S; Rho, M; Park, Tae Sun; Min, Dong Pil; Rho, Mannque
1995-01-01
Exchange vector currents are calculated up to one-loop order (corresponding to next-to-next-to-leading order) in chiral perturbation theory. As an illustration of the power of the approach, we apply the formalism to the classic nuclear process n+p\\rightarrow d +\\gamma at thermal energy. The exchange current correction comes out to be (4.5 \\pm 0.3) \\% in amplitude giving a predicted cross section \\sigma= (334\\pm 3)\\ {\\mbox mb} in excellent agreement with the experimental value (334.2\\pm 0.5)\\ {\\mbox mb}. Together with the axial charge transitions computed previously, this result provides a strong support for the power of chiral Lagrangians in nuclear physics. As a by-product of our results, we suggest an open problem in the application of chiral Lagrangian approach to nuclear processes that has to do with giving a physical meaning to the short-range correlations that play an important role in nuclei.
Light-front representation of chiral dynamics in peripheral transverse densities
Granados, C
2015-01-01
The nucleon's electromagnetic form factors are expressed in terms of the transverse densities of charge and magnetization at fixed light-front time. At peripheral transverse distances $b = O(M_\\pi^{-1})$ the densities are governed by chiral dynamics and can be calculated model-independently using chiral effective field theory (EFT). We represent the leading-order chiral EFT results for the peripheral transverse densities as overlap integrals of chiral light-front wave functions, describing the transition of the initial nucleon to soft pion-nucleon intermediate states and back. The new representation (a) explains the parametric order of the peripheral transverse densities; (b) establishes an inequality between the spin-independent and -dependent densities; (c) exposes the role of pion orbital angular momentum in chiral dynamics; (d) reveals a large left-right asymmetry of the current in a transversely polarized nucleon and suggests a simple interpretation. The light-front representation enables a first-quantiz...
Chiral logs in twisted mass lattice QCD with large isospin breaking
Bar, Oliver
2010-01-01
The pion masses and the pion decay constant are calculated to 1-loop order in twisted mass Wilson chiral perturbation theory, assuming a large pion mass splitting and tuning to maximal twist. Taking the large mass splitting at leading order in the chiral expansion leads to significant modifications in the chiral logarithms. For example, the result for the charged pion mass contains a chiral logarithm that involves the neutral pion mass instead of the charged one. Similar modifications appear in the results for the neutral pion mass and the decay constant. These new results are used in fits to lattice data obtained recently by the European twisted mass collaboration. The data can be fitted well, in general better than with the standard chiral perturbation theory expressions that ignore the mass splitting. The impact on the extraction of low-energy couplings is briefly discussed.
Lattice calculations for A=3,4,6,12 nuclei using chiral effective field theory
Epelbaum, Evgeny; Lee, Dean; Meißner, Ulf-G
2010-01-01
We present lattice calculations for the ground state energies of tritium, helium-3, helium-4, lithium-6, and carbon-12 nuclei. Our results were previously summarized in a letter publication. This paper provides full details of the calculations. We include isospin-breaking, Coulomb effects, and interactions up to next-to-next-to-leading order in chiral effective field theory.
The electric dipole form factor of the nucleon in chiral perturbation theory to subleading order
Mereghetti, E; de Vries, Jordy; Hockings, W.H.; Maekawa, C.M.; van Kolck, U
2011-01-01
The electric dipole form factor (EDFF) of the nucleon stemming from the QCD ¯ term and from the quark color-electric dipole moments is calculated in chiral perturbation theory to sub-leading order. This is the lowest order in which the isoscalar EDFF receives a calculable, non-analytic contribution
Chiral rotational spectroscopy
Cameron, Robert P.; Götte, Jörg B.; Barnett, Stephen M.
2016-09-01
We introduce chiral rotational spectroscopy, a technique that enables the determination of the orientated optical activity pseudotensor components BX X, BY Y, and BZ Z of chiral molecules, in a manner that reveals the enantiomeric constitution of a sample and provides an incisive signal even for a racemate. Chiral rotational spectroscopy could find particular use in the analysis of molecules that are chiral solely by virtue of their isotopic constitution and molecules with multiple chiral centers. A basic design for a chiral rotational spectrometer together with a model of its functionality is given. Our proposed technique offers the more familiar polarizability components αX X, αY Y, and αZ Z as by-products, which could see it find use even for achiral molecules.
Kalaydzhyan, Tigran
2014-01-01
We argue that the strongly coupled quark-gluon plasma formed at LHC and RHIC can be considered as a chiral superfluid. The "normal" component of the fluid is the thermalized matter in common sense, while the "superfluid" part consists of long wavelength (chiral) fermionic states moving independently. We use the bosonization procedure with a finite cut-off and obtain a dynamical axion-like field out of the chiral fermionic modes. Then we use relativistic hydrodynamics for macroscopic description of the effective theory obtained after the bosonization. Finally, solving the hydrodynamic equations in gradient expansion, we find that in the presence of external electromagnetic fields or rotation the motion of the "superfluid" component gives rise to the chiral magnetic, chiral vortical, chiral electric and dipole wave effects. Latter two effects are specific for a two-component fluid, which provides us with crucial experimental tests of the model.
Emerging chirality in nanoscience.
Wang, Yong; Xu, Jun; Wang, Yawen; Chen, Hongyu
2013-04-07
Chirality in nanoscience may offer new opportunities for applications beyond the traditional fields of chirality, such as the asymmetric catalysts in the molecular world and the chiral propellers in the macroscopic world. In the last two decades, there has been an amazing array of chiral nanostructures reported in the literature. This review aims to explore and categorize the common mechanisms underlying these systems. We start by analyzing the origin of chirality in simple systems such as the helical spring and hair vortex. Then, the chiral nanostructures in the literature were categorized according to their material composition and underlying mechanism. Special attention is paid to highlight systems with original discoveries, exceptional structural characteristics, or unique mechanisms.
Mechanical separation of chiral dipoles by chiral light
Canaguier-Durand, Antoine; Genet, Cyriaque; Ebbesen, Thomas W
2013-01-01
Optical forces take on a specific form when involving chiral light fields interacting with chiral objects. We show that optical chirality density and flow can have mechanical effects through reactive and dissipative components of chiral forces exerted on chiral dipoles. Remarkably, these force components are directly related to standard observables: optical rotation and circular dichroism, respectively. As a consequence, resulting forces and torques are dependent on the enantiomeric form of the chiral dipole. This leads to promising strategies for the mechanical separation of chiral objects using chiral light forces.
Banerjee, S. N.; Chakraborty, S. N.
1980-01-01
Presents the outline of an approach related to the teaching of the chapter on bound and scattering states in a short-range potential, which forms a standard part of an undergraduate quantum mechanics course or nuclear physics course. (HM)
Isospin-violating nucleon-nucleon forces using the method of unitary transformation
Evgeny Epelbaum; Ulf-G. Meissner
2005-02-01
Recently, we have derived the leading and subleading isospin-breaking three-nucleon forces using the method of unitary transformation. In the present work we extend this analysis and consider the corresponding two-nucleon forces using the same approach. Certain contributions to the isospin-violating one- and two-pion exchange potential have already been discussed by various groups within the effective field theory framework. Our findings agree with the previously obtained results. In addition, we present the expressions for the subleading charge-symmetry-breaking two-pion exchange potential which were not considered before. These corrections turn out to be numerically important. Together with the three-nucleon force results presented in our previous work, the results of the present study specify completely isospin-violating nuclear force up to the order {Lambda}{sup 5}.
Nuclear Stability and Nucleon-Nucleon Interactions in Introductory and General Chemistry Textbooks
Millevolte, Anthony
2010-01-01
The nucleus is a highly dense and highly charged substructure of atoms. In the nuclei of all atoms beyond hydrogen, multiple protons are in close proximity to each other in spite of strong electrostatic repulsions between them. The attractive internucleon strong force is described and its origin explained by using a simple quark model for the…
Energy dependence of slope parameter in elastic nucleon-nucleon scattering
Okorokov, V A
2015-01-01
The study of slope parameter is presented for elastic proton-proton and antiproton-proton scattering with taking into account the resent experimental data at high energies. The expanded logarithmic approximations allow the description of the experimental slopes in all available energy range reasonably. Accounting for the LHC results leads to the dramatic change of behavior of the quadratic in logarithm approximation at high energies and to the closer trends for all fitting functions under study in comparison with the analysis at collision energies up to the 200 GeV. The estimations of the asymptotic shrinkage parameter $\\alpha'_{\\cal{P}}$ are discussed. Predictions for diffraction slope parameter are obtained for some proton-proton and antiproton-proton facilities.
Microscopic Three-Body Force Effect on Nucleon-Nucleon Cross Sections in Symmetric Nuclear Matter
ZHANG Hong-Fei; ZUO Wei; Lombardo Umberto; LI Zeng-Hua; LI Jun-Qing
2008-01-01
We provide a microscopic calculation of neutron-proton and proton-proton cross sections in symmetric nuclear matter at various densities, using the Brueckner-Hartree-Fock approximation scheme with the Argonne V14 potential including the contribution of microscopic three-body force. We investigate separately the effects of three-body force on the effective mass and on the scattering amplitude. In the present calculation, the rearrangement contribution of three-body force is considered, which will reduce the neutron and proton effective mass, and depress the amplitude of cross section. The effect of three body force is shown to be repulsive, especially in high densities and large momenta, which will suppress the cross section markedly.
Bacelar, JCS
2001-01-01
The real- and virtual-photon emission during interactions between few-nucleon systems have been investigated at KVI with a 190 MeV proton beam. Here I will concentrate on the discussion of the results of the virtual-photon emission for the proton-proton system and proton-deuteron capture. Prediction
Low-energy theorems for nucleon-nucleon scattering at Mπ=450 MeV
Baru, V.; Epelbaum, E.; Filin, A. A.
2016-07-01
We apply the low-energy theorems to analyze the recent lattice QCD results for the two-nucleon system at a pion mass of Mπ≃450 MeV obtained by the NPLQCD Collaboration. We find that the binding energies of the deuteron and dineutron are inconsistent with the low-energy behavior of the corresponding phase shifts within the quoted uncertainties and vice versa. Using the binding energies of the deuteron and dineutron as input, we employ the low-energy theorems to predict the phase shifts and extract the scattering length and the effective range in the S31 and S10 channels. Our results for these quantities are consistent with those obtained by the NPLQCD Collaboration from effective field theory analyses but are in conflict with their determination based on the effective-range approximation.
Bacelar, JCS
2001-01-01
The real- and virtual-photon emission during interactions between few-nucleon systems have been investigated at KVI with a 190 MeV proton beam. Here I will concentrate on the discussion of the results of the virtual-photon emission for the proton-proton system and proton-deuteron capture. Prediction
Two Pion Production in Nucleon-Nucleon Collisions at Intermediate Energies
Alvarez-Ruso, L; Hernández, E
1998-01-01
We have developed a model for the N N --> N N pi pi reaction and evaluated cross sections for the different charged channels. The low energy part of those channels where the pions can be in an isospin zero state is dominated by N* excitation, driven by an isoscalar source followed by the decay N* --> N (pi pi, T=0, s-wave). At higher energies, and in channels where the pions are not in T=0, Delta excitation mechanisms become relevant.
Nucleon-nucleon effective potential in dense matter including rho-meson exchange
Mornas, L; Pérez, A
2002-01-01
We obtain the RPA summed one-meson exchange potential between nucleons in symmetric nuclear matter at zero temperature, from a model which includes rho, sigma, omega and pi mesons. The behavior of rho mesons inside the medium is first discussed using different schemes to extract a finite contribution from the vacuum polarization. These schemes give qualitatively different results for the in-medium rho mass. The results are discussed in connection with the nonrenormalizability of the model. We next study the modified potential as density increases. In the intermediate-distance range, it is qualitatively modified by matter and vacuum effects. In the long-distance range (r>2 fm), one observes the presence of oscillations, which are not present in free space. Features on this distance range are insensitive to the renormalization scheme.
Comment on "More on Heisenberg's model for high energy nucleon-nucleon scattering"
Block, Martin M; Ha, Phuoc; Halzen, Francis
2016-01-01
We comment on the treatment of asymptotic black-disk scattering in a recent paper of Nastase and Sonnenschein, Phys.\\ Rev.\\ D\\ {\\bf 92}, 015028 (2015), on scattering in an updated version of the Heisenberg model which gives $pp$ and $\\bar{p}p$ cross sections which increase at very high energies as $\\ln^2s$. We show that the total cross section they define does not correspond to that measured in experiments, with the result that their limit for the ratio $\\sigma_{\\rm elas}/\\sigma_{\\rm tot}$ is too small by a factor 2. The correct ratio for black-disk scattering, $\\sigma_{\\rm elas}/\\sigma_{\\rm tot} \\rightarrow 1/2$ for $s\\rightarrow\\infty$, is strongly supported by experiment.
Effects of pion-fold-pion diagrams in the energy-independent nucleon-nucleon potential
de Guzman, G.; Kuo, T. T. S.; Holinde, K.; Machleidt, R.; Faessler, A.; Müther, H.
1985-10-01
Based on a T-matrix equivalence theory, an energy-independent or locally energy-dependent nucléon-nucléon potential VNN derived from meson exchanges is studied. The potential, given as a series expansion of folded diagrams, is independent of the asymptotic energy of the scattering nucleons. It is, however, locally energy dependent in the sense that its matrix elements depend on the energies associated with its bra and ket states a and b. Our formulation makes use of right-hand-side on-shell T-matrix equivalence of the field-theoretical and potential descriptions when limited to the space of neutrons and protons only. This preserves not only scattering (e.g. phase shifts, projections of wave functions) but also bound-state properties. The matrix elements of V were calculated for two potential models, one based on one-pion exchange (OPEP) and the other on one-boson exchange (OBEP) using {π, ρ, σ, ω, δ, η }. Three types of phase-shift calculations have been carried out to study the viability of constructing an energy-independent potential using the folded-diagram expansion: (A) NN phase shifts for an energy-dependent OPEP and OBEP. For the OBEP we used parameters adjusted to fit experimental data. (B) The same phase shifts for the energy-independent case for both OPEP and OBEP. (C) Repetition of (B) with effects of the two-pion folded diagrams included. Our results show two important points: (i) folded diagrams are of essential importance, and (ii) the first-order folded diagrams contain the dominant effect and the neglect of terms with more than two folds can be regarded as a good approximation. The effects of folded diagrams are large especially for low partial waves and high energies. For high partial waves ( J greater than 2) the folded terms are negligible, and the phase shifts given by (A), (B) and (C) practically coincide.
Neutron Skin Thickness of Nuclei and Effective Nucleon-Nucleon Interactions
LIU Min; WANG Ning; LI Zhu-Xia; WU Xi-Zhen
2006-01-01
@@ The Skyrme energy density functional is applied to study the ground state properties of a series of finite nuclei.The charge rms radii, neutron rms radii, and the neutron skin thickness for some nuclei are calculated and compared with the experimental data. The constraint on the effective interactions, especially, the density dependence of the isospin-dependent part of Skyrme interactions is extracted by the data of neutron skin thicknesses of 208 pb and isotopes of Sn.
Probing Isospin Dependence of In-medium Nucleon-nucleon Cross Section by Nucleon Emissions
无
2001-01-01
Fig.1 shows the impact parameter-averaged asymptotic values of the number of the emitted neutrons N_n and the number of the emitted protons N_p(when the values of N_p and N_n at t=200 fm/c become nearly constants) i.e.b(top window)andb(bottom window)as a function of the beam energy with momentum dependent intraction for the systems~(76)Kr+~(40)Ca(left windows)and ~(76)Kr+~(76)Kr(right windows)in five cases:
Energy Dependence of Slope Parameter in Elastic Nucleon-Nucleon Scattering
V. A. Okorokov
2015-01-01
Full Text Available The diffraction slope parameter is investigated for elastic proton-proton and proton-antiproton scattering based on all the available experimental data at low and intermediate momentum transfer values. Energy dependence of the elastic diffraction slope is approximated by various analytic functions. The expanded “standard” logarithmic approximations with minimum number of free parameters allow description of the experimental slopes in all the available energy range reasonably. The estimations of asymptotic shrinkage parameter αP′ are obtained for various |t| domains based on all the available experimental data. Various approximations differ from each other both in the low energy and very high energy domains. Predictions for diffraction slope parameter are obtained for elastic proton-proton scattering from NICA up to future collider (FCC/VLHC energies, for proton-antiproton elastic reaction in FAIR energy domain for various approximation functions.
Kim, Cheol-Joo; Sánchez-Castillo, A.; Ziegler, Zack; Ogawa, Yui; Noguez, Cecilia; Park, Jiwoong
2016-06-01
Chiral materials possess left- and right-handed counterparts linked by mirror symmetry. These materials are useful for advanced applications in polarization optics, stereochemistry and spintronics. In particular, the realization of spatially uniform chiral films with atomic-scale control of their handedness could provide a powerful means for developing nanodevices with novel chiral properties. However, previous approaches based on natural or grown films, or arrays of fabricated building blocks, could not offer a direct means to program intrinsic chiral properties of the film on the atomic scale. Here, we report a chiral stacking approach, where two-dimensional materials are positioned layer-by-layer with precise control of the interlayer rotation (θ) and polarity, resulting in tunable chiral properties of the final stack. Using this method, we produce left- and right-handed bilayer graphene, that is, a two-atom-thick chiral film. The film displays one of the highest intrinsic ellipticity values (6.5 deg μm-1) ever reported, and a remarkably strong circular dichroism (CD) with the peak energy and sign tuned by θ and polarity. We show that these chiral properties originate from the large in-plane magnetic moment associated with the interlayer optical transition. Furthermore, we show that we can program the chiral properties of atomically thin films layer-by-layer by producing three-layer graphene films with structurally controlled CD spectra.
Sen, Srimoyee
2016-01-01
We study shock waves in relativistic chiral matter. We argue that the conventional Rankine- Hugoinot relations are modified due to the presence of chiral transport phenomena. We show that the entropy discontinuity in a weak shock wave is linearly proportional to the pressure discontinuity when the effect of chiral transport becomes sufficiently large. We also show that rarefaction shock waves, which do not exist in usual nonchiral fluids, can appear in chiral matter. These features are exemplified by shock propagation in dense neutrino matter in the hydrodynamic regime.
Anomalous chiral superfluidity
Lublinsky, Michael, E-mail: lublinsky@phys.uconn.ed [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States); Physics Department, Ben-Gurion University, Beer Sheva 84105 (Israel); Zahed, Ismail [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794 (United States)
2010-02-08
We discuss both the anomalous Cartan currents and the energy-momentum tensor in a left chiral theory with flavor anomalies as an effective theory for flavored chiral phonons in a chiral superfluid with the gauged Wess-Zumino-Witten term. In the mean-field (leading tadpole) approximation the anomalous Cartan currents and the energy-momentum tensor take the form of constitutive currents in the chiral superfluid state. The pertinence of higher order corrections and the Adler-Bardeen theorem is briefly noted.
The lowest-lying baryon masses in covariant SU(3)-flavor chiral perturbation theory
Martin-Camalich, J; Vacas, M J Vicente
2010-01-01
We present an analysis of the baryon-octet and -decuplet masses using covariant SU(3)-flavor chiral perturbation theory up to next-to-leading order. Besides the description of the physical masses we address the problem of the lattice QCD extrapolation. Using the PACS-CS collaboration data we show that a good description of the lattice points can be achieved at next-to-leading order with the covariant loop amplitudes and phenomenologically determined values for the meson-baryon couplings. Moreover, the extrapolation to the physical point up to this order is found to be better than the linear one given at leading-order by the Gell-Mann-Okubo approach. The importance that a reliable combination of lattice QCD and chiral perturbation theory may have for hadron phenomenology is emphasized with the prediction of the pion-baryon and strange-baryon sigma terms.
Doped Chiral Polymer Metamaterials Project
National Aeronautics and Space Administration — Doped Chiral Polymer Metamaterials (DCPM) with tunable resonance frequencies have been developed by adding plasmonic inclusions into chiral polymers with variable...
Chiral three-nucleon force at N^4LO I: Longest-range contributions
Krebs, Hermann; Epelbaum, Evgeny
2012-01-01
We derive the sub-subleading two-pion exchange contributions to the three-nucleon force which appear at next-to-next-to-next-to-next-to-leading order in chiral effective field theory. In order to determine the low-energy constants, a complete analysis of pion-nucleon scattering at the subleading-loop order in the heavy-baryon expansion is carried out utilizing the power counting scheme employed in the derivation of the nuclear forces. We discuss the convergence of the chiral expansion for this particular three-nucleon force topology and give the values of the low-energy constants which provide the most realistic description of the three-nucleon force when the chiral expansion is truncated at next-to-next-to-leading order.
Kataev, A L; Parente, G; Sidorov, A V
1998-01-01
We present the results of the next-to-next-to-leading order QCD analysis of the recently revised experimental data of the CCFR collaboration for the $xF_3$ structure function using the Jacobi polynomial expansion method. The effects of the higher twist contributions are included into the fits following the infrared renormalon motivated model. The special attention is paid to the checks of the predictive abilities of the infrared renormalon model and to the independent extraction of the $x$-shape of the twist-4 contributions to the $xF_3$ structure function in the process of the leading order, next-to-leading order and next-to-next-to-leading order fits of the revised CCFR data. We stress that at the next-to-next-to-leading order the results for We obtain the following result $\\alpha_s(M_Z)^{NNLO}=0.117 \\pm 0.002(stat) \\pm 0.005 (syst)\\pm 0.003 (theory)$. The comparison of the outcomes of our next-to-leading order and next-to-next-to-leading order analysis indicate that the theoretical QCD uncertainties were u...
Next-to-leading-order electroweak corrections to $pp \\to W^+W^-\\to$ 4 leptons at the LHC
Biedermann, Benedikt; Denner, Ansgar; Dittmaier, Stefan; Hofer, Lars; Jager, Barbara; Salfelder, Lukas
2016-01-01
We present results of the first calculation of next-to-leading-order electroweak corrections to W-boson pair production at the LHC that fully takes into account leptonic W-boson decays and off-shell effects. Employing realistic event selections, we discuss the corrections in situations that are typical for the study of W-boson pairs as a signal process or of Higgs-boson decays $H\\to W W^*$, to which W-boson pair production represents an irreducible background. In particular, we compare the full off-shell results, obtained treating the W-boson resonances in the complex-mass scheme, to previous results in the so-called double-pole approximation, which is based on an expansion of the loop amplitudes about the W resonance poles. At small and intermediate scales, i.e. in particular in angular and rapidity distributions, the two approaches show the expected agreement at the level of fractions of a percent, but larger differences appear in the TeV range. For transverse-momentum distributions, the differences can eve...
Marsat, Sylvain; Faye, Guillaume; Blanchet, Luc
2012-01-01
We compute next-to-next-to-leading order spin contributions to the post-Newtonian equations of motion for binaries of compact objects, such as black holes or neutron stars. For maximally spinning black holes, those contributions are of third-and-a-half post-Newtonian (3.5PN) order, improving our knowledge of the equations of motion, already known for non-spinning objects up to this order. Building on previous work, we represent the rotation of the two bodies using a pole-dipole matter stress-energy tensor, and iterate Einstein's field equations for a set of potentials parametrizing the metric in harmonic coordinates. Checks of the result include the existence of a conserved energy, the approximate global Lorentz invariance of the equations of motion in harmonic coordinates, and the recovery of the motion of a spinning object on a Kerr background in the test-mass limit. We verified the existence of a contact transformation, together with a redefinition of the spin variables that makes our result equivalent to ...
A new effective-one-body Hamiltonian with next-to-leading order spin-spin coupling
Balmelli, Simone
2015-01-01
We present a new effective-one-body (EOB) Hamiltonian with next-to-leading order (NLO) spin-spin coupling for black hole binaries endowed with arbitrarily oriented spins. The Hamiltonian is based on the model for parallel spins and equatorial orbits developed in [Physical Review D 90, 044018 (2014)], but differs from it in several ways. In particular, the NLO spin-spin coupling is not incorporated by a redefinition of the centrifugal radius $r_c$, but by separately modifying certain sectors of the Hamiltonian, which are identified according to their dependence on the momentum vector. The gauge-fixing procedure we follow allows us to reduce the 25 different terms of the NLO spin-spin Hamiltonian in Arnowitt-Deser-Misner coordinates to only 9 EOB terms. This is an improvement with respect to the EOB model recently proposed in [Physical Review D 91, 064011 (2015)], where 12 EOB terms were involved. Another important advantage is the remarkably simple momentum structure of the spin-spin terms in the effective Ham...
Khanpour, Hamzeh
2016-01-01
We perform a next-to-next-to-leading order (NNLO) analysis of nuclear parton distribution functions (nPDFs) using neutral current charged-lepton ($\\ell ^\\pm$ + nucleus) deeply inelastic scattering (DIS) data and Drell-Yan (DY) cross-section ratios $\\sigma_{DY}^{A}/\\sigma_{DY}^{A^\\prime}$ for several nuclear targets. We study in details the parameterizations and the atomic mass (A) dependence of the nuclear PDFs at this order. The present nuclear PDFs global analysis provides us a complete set of nuclear PDFs, $f_i^{(A,Z)}(x,Q^2)$, with a full functional dependence on $x$, A, Q$^2$. The uncertainties of the obtained nuclear modification factors for each parton flavour are estimated using the well-known Hessian method. The nuclear charm quark distributions are also added into the analysis. We compare the parametrization results with the available data and the results of other nuclear PDFs groups. We found our nuclear PDFs to be in reasonably good agreement with them. The estimates of errors provided by our glob...
Next-to-leading-order electroweak corrections to pp → W+W- → 4 leptons at the LHC
Biedermann, B.; Billoni, M.; Denner, A.; Dittmaier, S.; Hofer, L.; Jäger, B.; Salfelder, L.
2016-06-01
We present results of the first calculation of next-to-leading-order electroweak corrections to W-boson pair production at the LHC that fully takes into account leptonic W-boson decays and off-shell effects. Employing realistic event selections, we discuss the corrections in situations that are typical for the study of W-boson pairs as a signal process or of Higgs-boson decays H → WW∗, to which W-boson pair production represents an irreducible background. In particular, we compare the full off-shell results, obtained treating the W-boson resonances in the complex-mass scheme, to previous results in the so-called double-pole approximation, which is based on an expansion of the loop amplitudes about the W resonance poles. At small and intermediate scales, i.e. in particular in angular and rapidity distributions, the two approaches show the expected agreement at the level of fractions of a percent, but larger differences appear in the TeV range. For transverse-momentum distributions, the differences can even exceed the 10% level in the TeV range where "background diagrams" with one instead of two resonant W bosons gain in importance because of recoil effects.
Vanasse, Jared
2015-01-01
In the three-body system of ${}^3\\mathrm{H}$ we show how perturbative corrections can be added to the leading ordering triton vertex function. Using this new scheme we calculate the triton charge form factor and use it to extract the triton charge radius to next-to-leading-order, yielding a prediction of 1.58~fm. We show that a new counter-term will be needed to predict the triton charge radius at next-to-next-to-leading order.
Applications of chiral symmetry
Pisarski, R D
1995-01-01
I discuss several topics in the applications of chiral symmetry at nonzero temperature, including: where the rho goes, disoriented chiral condensates, and the phase diagram for QCD with 2+1 flavors. (Based upon talks presented at the "Workshop on Finite Temperature QCD", Wuhan, P.R.C., April, 1994.)
Geometrical approach to central molecular chirality: a chirality selection rule
Capozziello, S.; Lattanzi, A
2004-01-01
Chirality is of primary importance in many areas of chemistry and has been extensively investigated since its discovery. We introduce here the description of central chirality for tetrahedral molecules using a geometrical approach based on complex numbers. According to this representation, for a molecule having n chiral centres, it is possible to define an index of chirality. Consequently a chirality selection rule has been derived which allows the characterization of a molecule as achiral, e...
Molecular model for chirality phenomena.
Latinwo, Folarin; Stillinger, Frank H; Debenedetti, Pablo G
2016-10-21
Chirality is a hallmark feature for molecular recognition in biology and chemical physics. We present a three-dimensional continuum model for studying chirality phenomena in condensed phases using molecular simulations. Our model system is based upon a simple four-site molecule and incorporates non-trivial kinetic behavior, including the ability to switch chirality or racemize, as well as thermodynamics arising from an energetic preference for specific chiral interactions. In particular, we introduce a chiral renormalization parameter that can locally favor either homochiral or heterochiral configurations. Using this model, we explore a range of chirality-specific phenomena, including the kinetics of chiral inversion, the mechanism of spontaneous chiral symmetry breaking in the liquid, chirally driven liquid-liquid phase separation, and chiral crystal structures.
Applications of chiral symmetry
Pisarski, R.D.
1995-03-01
The author discusses several topics in the applications of chiral symmetry at nonzero temperature. First, where does the rho go? The answer: up. The restoration of chiral symmetry at a temperature T{sub {chi}} implies that the {rho} and a{sub 1} vector mesons are degenerate in mass. In a gauged linear sigma model the {rho} mass increases with temperature, m{sub {rho}}(T{sub {chi}}) > m{sub {rho}}(0). The author conjectures that at T{sub {chi}} the thermal {rho} - a{sub 1}, peak is relatively high, at about {approximately}1 GeV, with a width approximately that at zero temperature (up to standard kinematic factors). The {omega} meson also increases in mass, nearly degenerate with the {rho}, but its width grows dramatically with temperature, increasing to at least {approximately}100 MeV by T{sub {chi}}. The author also stresses how utterly remarkable the principle of vector meson dominance is, when viewed from the modern perspective of the renormalization group. Secondly, he discusses the possible appearance of disoriented chiral condensates from {open_quotes}quenched{close_quotes} heavy ion collisions. It appears difficult to obtain large domains of disoriented chiral condensates in the standard two flavor model. This leads to the last topic, which is the phase diagram for QCD with three flavors, and its proximity to the chiral critical point. QCD may be very near this chiral critical point, and one might thereby generated large domains of disoriented chiral condensates.
K- nuclear potentials from in-medium chirally motivated models
Cieplý, A.; Friedman, E.; Gal, A.; Gazda, D.; Mareš, J.
2011-10-01
A self-consistent scheme for constructing K- nuclear optical potentials from subthreshold in-medium K¯N s-wave scattering amplitudes is presented and applied to analysis of kaonic atoms data and to calculations of K- quasibound nuclear states. The amplitudes are taken from a chirally motivated meson-baryon coupled-channel model, both at the Tomozawa-Weinberg leading order and at the next to leading order. Typical kaonic atoms potentials are characterized by a real part -ReVK-chiral=85±5 MeV at nuclear matter density, in contrast to half this depth obtained in some derivations based on in-medium K¯N threshold amplitudes. The moderate agreement with data is much improved by adding complex ρ- and ρ2-dependent phenomenological terms, found to be dominated by ρ2 contributions that could represent K¯NN→YN absorption and dispersion, outside the scope of meson-baryon chiral models. Depths of the real potentials are then near 180 MeV. The effects of p-wave interactions are studied and found secondary to those of the dominant s-wave contributions. The in-medium dynamics of the coupled-channel model is discussed and systematic studies of K- quasibound nuclear states are presented.
Chiral supergravity and anomalies
Mielke, E W; Macias, Alfredo; Mielke, Eckehard W.
1999-01-01
Similarily as in the Ashtekar approach, the translational Chern-Simons term is, as a generating function, instrumental for a chiral reformulation of simple (N=1) supergravity. After applying the algebraic Cartan relation between spin and torsion, the resulting canonical transformation induces not only decomposition of the gravitational fields into selfdual and antiselfdual modes, but also a splitting of the Rarita-Schwinger fields into their chiral parts in a natural way. In some detail, we also analyze the consequences for axial and chiral anomalies.
Spectral signatures of chirality
Pedersen, Jesper Goor; Mortensen, Asger
2009-01-01
We present a new way of measuring chirality, via the spectral shift of photonic band gaps in one-dimensional structures. We derive an explicit mapping of the problem of oblique incidence of circularly polarized light on a chiral one-dimensional photonic crystal with negligible index contrast...... to the formally equivalent problem of linearly polarized light incident on-axis on a non-chiral structure with index contrast. We derive analytical expressions for the first-order shifts of the band gaps for negligible index contrast. These are modified to give good approximations to the band gap shifts also...
Catalysis of Dynamical Chiral Symmetry Breaking by Chiral Chemical Potential
Braguta, V V
2016-01-01
In this paper we study the properties of media with chiral imbalance parameterized by chiral chemical potential. It is shown that depending on the strength of interaction between constituents in the media the chiral chemical potential either creates or enhances dynamical chiral symmetry breaking. Thus the chiral chemical potential plays a role of the catalyst of dynamical chiral symmetry breaking. Physically this effect results from the appearance of the Fermi surface and additional fermion states on this surface which take part in dynamical chiral symmetry breaking. An interesting conclusion which can be drawn is that at sufficiently small temperature chiral plasma is unstable with respect to condensation of Cooper pairs and dynamical chiral symmetry breaking even for vanishingly small interactions between constituents.
Charmless chiral perturbation theory for N_f=2+1+1 twisted mass lattice QCD
Bar, Oliver
2014-01-01
The chiral Lagrangian describing the low-energy behavior of N_f=2+1+1 twisted mass lattice QCD is constructed through O(a^2). In contrast to existing results the effects of a heavy charm quark are consistently removed, leaving behind a charmless 3-flavor Lagrangian. This Lagrangian is used to compute the pion and kaon masses to one loop in a regime where the pion mass splitting is large and taken as a leading order effect. In comparison with continuum chiral perturbation theory additional chiral logarithms are present in the results. In particular, chiral logarithms involving the neutral pion mass appear. These predict rather large finite volume corrections in the kaon mass which roughly account for the finite volume effects observed in lattice data.
Novozhilov, V Yu; Novozhilov, Victor; Novozhilov, Yuri
2002-01-01
We discuss specific features of color chiral solitons (asymptotics, possibility of confainment, quantization) at example of isolated SU(2) color skyrmions, i.e. skyrmions in a background field which is the vacuum field forming the gluon condensate.
van den Broek, M; Van den Broeck, C
2008-04-04
We present the exact analysis of a chiral Brownian motor and heat pump. Optimization of the construction predicts, for a nanoscale device, frequencies of the order of kHz and cooling rates of the order of femtojoule per second.
Van Den Broek, Martijn; Van Den Broeck, Christian
2007-01-01
We present the exact analysis of a chiral Brownian motor and heat pump. Optimization of the construction predicts, for a nanoscale device, frequencies of the order of kHz and cooling rates of the order of femtojoule per second.
Electrodynamics of chiral matter
Qiu, Zebin; Cao, Gaoqing; Huang, Xu-Guang
2017-02-01
Many-body systems with chiral fermions can exhibit novel transport phenomena that violate parity and time-reversal symmetries, such as the chiral magnetic effect, the anomalous Hall effect, and the anomalous generation of charge. Based on the Maxwell-Chern-Simons electrodynamics, we examine some electromagnetic and optical properties of such systems including the electrostatics, the magnetostatics, the propagation of electromagnetic waves, the novel optical effects, etc.
Goldstein Gary R.
2015-01-01
Full Text Available Nucleon spin structure, transversity and the tensor charge are of central importance to understanding the role of QCD in hadronic physics. A new approach to measuring orbital angular momenta of quarks in the proton via twist 3 GPDs is shown. The “flexible parametrization” of chiral even GPDs is reviewed and its transformation into the chiral odd sector is discussed. The resulting parametrization is applied to recent data on π0 and η electroproduction.
Bernard, Véronique; Descotes-Genon, Sébastien; Silva, Luiz Vale
2016-08-01
Left-Right (LR) models are extensions of the Standard Model where left-right symmetry is restored at high energies, and which are strongly constrained by kaon mixing described in the framework of the |Δ S| = 2 effective Hamiltonian. We consider the short-distance QCD corrections to this Hamiltonian both in the Standard Model (SM) and in LR models. The leading logarithms occurring in these short-distance corrections can be resummed within a rigourous Effective Field Theory (EFT) approach integrating out heavy degrees of freedom progressively, or using an approximate simpler method of regions identifying the ranges of loop momentum generating large logarithms in the relevant two-loop diagrams. We compare the two approaches in the SM at next-to-leading order, finding a very good agreement when one scale dominates the problem, but only a fair agreement in the presence of a large logarithm at leading order. We compute the short-distance QCD corrections for LR models at next-to-leading order using the method of regions, and we compare the results with the EFT approach for the W W ' box with two charm quarks (together with additional diagrams forming a gauge-invariant combination), where a large logarithm occurs already at leading order. We conclude by providing next-to-leading-order estimates for cc, ct and tt boxes in LR models.
Bernard, Véronique [Groupe de Physique Théorique, Institut de Physique Nucléaire, UMR 8608, CNRS,University Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex (France); Descotes-Genon, Sébastien [Laboratoire de Physique Théorique, UMR 8627, CNRS, University Paris-Sud, Université Paris-Saclay,91405 Orsay Cedex (France); Silva, Luiz Vale [Groupe de Physique Théorique, Institut de Physique Nucléaire, UMR 8608, CNRS,University Paris-Sud, Université Paris-Saclay, 91406 Orsay Cedex (France); Laboratoire de Physique Théorique, UMR 8627, CNRS, University Paris-Sud, Université Paris-Saclay,91405 Orsay Cedex (France)
2016-08-23
Left-Right (LR) models are extensions of the Standard Model where left-right symmetry is restored at high energies, and which are strongly constrained by kaon mixing described in the framework of the |ΔS|=2 effective Hamiltonian. We consider the short-distance QCD corrections to this Hamiltonian both in the Standard Model (SM) and in LR models. The leading logarithms occurring in these short-distance corrections can be resummed within a rigourous Effective Field Theory (EFT) approach integrating out heavy degrees of freedom progressively, or using an approximate simpler method of regions identifying the ranges of loop momentum generating large logarithms in the relevant two-loop diagrams. We compare the two approaches in the SM at next-to-leading order, finding a very good agreement when one scale dominates the problem, but only a fair agreement in the presence of a large logarithm at leading order. We compute the short-distance QCD corrections for LR models at next-to-leading order using the method of regions, and we compare the results with the EFT approach for the WW{sup ′} box with two charm quarks (together with additional diagrams forming a gauge-invariant combination), where a large logarithm occurs already at leading order. We conclude by providing next-to-leading-order estimates for cc, ct and tt boxes in LR models.
Testing chiral effective theory with quenched lattice QCD
Giusti, Leonardo; Necco, S; Peña, C; Wennekers, J; Wittig, H
2008-01-01
We investigate two-point correlation functions of left-handed currents computed in quenched lattice QCD with the Neuberger-Dirac operator. We consider two lattice spacings a~0.09,0.12 fm and two different lattice extents L~ 1.5, 2.0 fm; quark masses span both the p- and the epsilon-regimes. We compare the results with the predictions of quenched chiral perturbation theory, with the purpose of testing to what extent the effective theory reproduces quenched QCD at low energy. In the p-regime we test volume and quark mass dependence of the pseudoscalar decay constant and mass; in the epsilon-regime, we investigate volume and topology dependence of the correlators. While the leading order behaviour predicted by the effective theory is very well reproduced by the lattice data in the range of parameters that we explored, our numerical data are not precise enough to test next-to-leading order effects.
Testing chiral effective theory with quenched lattice QCD
Giusti, L.; Hernández, P.; Necco, S.; Pena, C.; Wennekers, J.; Wittig, H.
2008-05-01
We investigate two-point correlation functions of left-handed currents computed in quenched lattice QCD with the Neuberger-Dirac operator. We consider two lattice spacings a simeq 0.09,0.12 fm and two different lattice extents L simeq 1.5,2.0 fm; quark masses span both the p- and the epsilon-regimes. We compare the results with the predictions of quenched chiral perturbation theory, with the purpose of testing to what extent the effective theory reproduces quenched QCD at low energy. In the p-regime we test volume and quark mass dependence of the pseudoscalar decay constant and mass; in the epsilon-regime, we investigate volume and topology dependence of the correlators. While the leading order behaviour predicted by the effective theory is very well reproduced by the lattice data in the range of parameters that we explored, our numerical data are not precise enough to test next-to-leading order effects.
Stefan Höche
2015-09-01
Full Text Available We present differential cross sections for the production of top-quark pairs in conjunction with up to two jets, computed at next-to-leading order in perturbative QCD and consistently merged with a parton shower in the Sherpa+OpenLoops framework. Top quark decays including spin correlation effects are taken into account at leading order accuracy. The calculation yields a unified description of top-pair plus multi-jet production, and detailed results are presented for various key observables at the Large Hadron Collider. A large improvement with respect to the multi-jet merging approach at leading order is found for the total transverse energy spectrum, which plays a prominent role in searches for physics beyond the Standard Model.
Parity- and Time Reversal-Violating Pion Nucleon Couplings: Higher Order Chiral Matching Relations
Seng, Chien-Yeah
2016-01-01
Parity- and time reversal-violating (PVTV) pion-nucleon couplings govern the magnitude of long-range contributions to nucleon and atomic electric dipole moments. When these couplings arise from chiral symmetry-breaking CP-violating operators, such as the QCD $\\theta$-term or quark chromoelectric dipole moments, one may relate hadronic matrix elements entering the PVTV couplings to nucleon and pion mass shifts by exploiting the corresponding chiral transformation properties at leading order (LO) in the chiral expansion. We compute the higher-order contributions to the lowest order relations arising from chiral loops and next-to-next-to leading order (NNLO) operators. We find that for the QCD $\\theta$-term the higher order contributions are analytic in the quark masses, while for the quark chromoelectric dipole moments and chiral symmetry-breaking four-quark operators, the matching relations also receive non-analytic corrections. Numerical estimates suggest that for the isoscalar PVTV pion-nucleon coupling, the...
Reducible chiral four-body interactions in nuclear matter
Kaiser, N
2015-01-01
The method of unitary transformations generates five classes of leading-order reducible chiral four-nucleon interactions which involve pion-exchanges and a spin-spin contact-term. Their first-order contributions to the energy per particle of isospin-symmetric nuclear matter and pure neutron matter are evaluated in detail. For most of the closed four-loop diagrams the occurring integrals over four Fermi-spheres can be reduced to easily manageable one- or two-parameter integrals. One observes substantial cancelations among the different contributions arising from 2-ring and 1-ring diagrams. Altogether, the net attraction generated by the chiral four-nucleon interaction does not exceed values of $-1.3$\\,MeV for densities $\\rho<2\\rho_0$.
Chiral Dynamics in Pion-Photon Reactions Habilitation
Friedrich, Jan Michael
As the lightest particle of the strong force, the pion plays a central role in the field of strong interactions, and understanding its properties is of prime relevance for understanding the strong interaction in general. The low-energy behaviour of pions is of particular interest. Although the quark-gluon substructure and their quantum chromodynamics is not apparent then, this specific inner structure causes the presence of approximate symmetries in pion-pion interactions and in pion decays, which gives rise to the systematic description of processes involving pions in terms of few low-energy constants. Specifically, the chiral symmetry and its spontaneous and explicit breaking, treated in chiral perturbation theory (ChPT), leads to firm predictions for low-energy properties of the pion. To those belong the electromagnetic polarisabilities of the pion, describing the leading-order structure effect in pion Compton scattering. The research presented in this work is concerned with the interaction of pions and ph...
Chiral perturbation theory of muonic hydrogen Lamb shift: polarizability contribution
Alarcón, Jose Manuel; Pascalutsa, Vladimir
2013-01-01
The proton polarizability effect in the muonic-hydrogen Lamb shift comes out as a prediction of baryon chiral perturbation theory at leading order and our calculation yields for it: $\\Delta E^{(\\mathrm{pol})} (2P-2S) = 8^{+3}_{-1}\\, \\mu$eV. This result is consistent with most of evaluations based on dispersive sum rules, but is about a factor of two smaller than the recent result obtained in {\\em heavy-baryon} chiral perturbation theory. We also find that the effect of $\\Delta(1232)$-resonance excitation on the Lamb-shift is suppressed, as is the entire contribution of the magnetic polarizability; the electric polarizability dominates. Our results reaffirm the point of view that the proton structure effects, beyond the charge radius, are too small to resolve the `proton radius puzzle'.
Generalized polarizabilities of the nucleon in baryon chiral perturbation theory
Lensky, Vadim; Pascalutsa, Vladimir; Vanderhaeghen, Marc
2017-02-01
The nucleon generalized polarizabilities (GPs), probed in virtual Compton scattering (VCS), describe the spatial distribution of the polarization density in a nucleon. They are accessed experimentally via the process of electron-proton bremsstrahlung (ep→ epγ ) at electron-beam facilities, such as MIT-Bates, CEBAF (Jefferson Lab), and MAMI (Mainz). We present the calculation of the nucleon GPs and VCS observables at next-to-leading order in baryon chiral perturbation theory (Bχ PT), and confront the results with the empirical information. At this order our results are predictions, in the sense that all the parameters are well known from elsewhere. Within the relatively large uncertainties of our calculation we find good agreement with the experimental observations of VCS and the empirical extractions of the GPs. We find large discrepancies with previous chiral calculations - all done in heavy-baryon χ PT (HBχ PT) - and discuss the differences between Bχ PT and HBχ PT responsible for these discrepancies.
Reducible chiral four-body interactions in nuclear matter
Kaiser, N.; Milkus, R. [Technische Universitaet Muenchen, Physik-Department T39, Garching (Germany)
2016-01-15
The method of unitary transformations generates five classes of leading-order reducible chiral four-nucleon interactions which involve pion exchanges and a spin-spin contact term. Their first-order contributions to the energy per particle of isospin-symmetric nuclear matter and pure neutron matter are evaluated in detail. For most of the closed four-loop diagrams the occurring integrals over four Fermi spheres can be reduced to easily manageable one- or two-parameter integrals. One finds substantial compensations among the different contributions arising from 2-ring and 1-ring diagrams. Altogether, the net attraction generated by the chiral four-nucleon interaction does not exceed values of -1.3 MeV for densities ρ < 2ρ{sub 0}. (orig.)
Chiral Random Matrix Theory and Chiral Perturbation Theory
Damgaard, P H
2011-01-01
Spontaneous breaking of chiral symmetry in QCD has traditionally been inferred indirectly through low-energy theorems and comparison with experiments. Thanks to the understanding of an unexpected connection between chiral Random Matrix Theory and chiral Perturbation Theory, the spontaneous breaking of chiral symmetry in QCD can now be shown unequivocally from first principles and lattice simulations. In these lectures I give an introduction to the subject, starting with an elementary discussion of spontaneous breaking of global symmetries.
Chiral Random Matrix Theory and Chiral Perturbation Theory
Damgaard, Poul H, E-mail: phdamg@nbi.dk [Niels Bohr International Academy and Discovery Center, The Niels Bohr Institute, Blegdamsvej 17, DK-2100 Copenhagen (Denmark)
2011-04-01
Spontaneous breaking of chiral symmetry in QCD has traditionally been inferred indirectly through low-energy theorems and comparison with experiments. Thanks to the understanding of an unexpected connection between chiral Random Matrix Theory and chiral Perturbation Theory, the spontaneous breaking of chiral symmetry in QCD can now be shown unequivocally from first principles and lattice simulations. In these lectures I give an introduction to the subject, starting with an elementary discussion of spontaneous breaking of global symmetries.
Suzuki, Nozomu; Wang, Yichun; Elvati, Paolo; Qu, Zhi-Bei; Kim, Kyoungwon; Jiang, Shuang; Baumeister, Elizabeth; Lee, Jaewook; Yeom, Bongjun; Bahng, Joong Hwan; Lee, Jaebeom; Violi, Angela; Kotov, Nicholas A
2016-02-23
Chiral nanostructures from metals and semiconductors attract wide interest as components for polarization-enabled optoelectronic devices. Similarly to other fields of nanotechnology, graphene-based materials can greatly enrich physical and chemical phenomena associated with optical and electronic properties of chiral nanostructures and facilitate their applications in biology as well as other areas. Here, we report that covalent attachment of l/d-cysteine moieties to the edges of graphene quantum dots (GQDs) leads to their helical buckling due to chiral interactions at the "crowded" edges. Circular dichroism (CD) spectra of the GQDs revealed bands at ca. 210-220 and 250-265 nm that changed their signs for different chirality of the cysteine edge ligands. The high-energy chiroptical peaks at 210-220 nm correspond to the hybridized molecular orbitals involving the chiral center of amino acids and atoms of graphene edges. Diverse experimental and modeling data, including density functional theory calculations of CD spectra with probabilistic distribution of GQD isomers, indicate that the band at 250-265 nm originates from the three-dimensional twisting of the graphene sheet and can be attributed to the chiral excitonic transitions. The positive and negative low-energy CD bands correspond to the left and right helicity of GQDs, respectively. Exposure of liver HepG2 cells to L/D-GQDs reveals their general biocompatibility and a noticeable difference in the toxicity of the stereoisomers. Molecular dynamics simulations demonstrated that d-GQDs have a stronger tendency to accumulate within the cellular membrane than L-GQDs. Emergence of nanoscale chirality in GQDs decorated with biomolecules is expected to be a general stereochemical phenomenon for flexible sheets of nanomaterials.
The role of strange sea quarks in chiral extrapolations on the lattice
Descotes-Genon, S
2004-01-01
Since the strange quark has a light mass of order Lambda_QCD, fluctuations of sea s-s bar pairs may play a special role in the low-energy dynamics of QCD by inducing significantly different patterns of chiral symmetry breaking in the chiral limits N_f=2 (m_u=m_d=0, m_s physical) and N_f=3 (m_u=m_d=m_s=0). This effect of vacuum fluctuations of s-s bar pairs is related to the violation of the Zweig rule in the scalar sector, described through the two O(p^4) low-energy constants L_4 and L_6 of the three-flavour strong chiral lagrangian. In the case of significant vacuum fluctuations, three-flavour chiral expansions might exhibit a numerical competition between leading- and next-to-leading-order terms according to the chiral counting, and chiral extrapolations should be handled with a special care. We investigate the impact of the fluctuations of s-s bar pairs on chiral extrapolations in the case of lattice simulations with three dynamical flavours in the isospin limit. Information on the size of the vacuum fluct...
The reaction pi N-> pi pi N in chiral effective field theory with explicit Delta(1232)
Siemens, D; Epelbaum, E; Krebs, H; Meißner, Ulf-G
2014-01-01
The reaction pi N -> pi pi N is studied at tree level up to next-to-leading order in the framework of manifestly covariant baryon chiral perturbation theory with explicit Delta(1232) degrees of freedom. Using total cross section data to determine the relevant low-energy constants, predictions are made for various differential as well as total cross sections at higher energies. A detailed comparison of results based on the heavy-baryon and relativistic formulations of chiral perturbation theory with and without explicit Delta degrees of freedom is given.
Gold-plated moments of nucleon structure functions in baryon chiral perturbation theory
Lensky, Vadim; Pascalutsa, Vladimir
2014-01-01
We obtain leading- and next-to-leading order predictions of chiral perturbation theory for several prominent moments of nucleon structure functions. These free-parameter free results turn out to be in overall agreement with the available empirical information on all of the considered moments, in the region of low-momentum transfer ($Q^2 < 0.3$ GeV$^2$). Especially surprising is the situation for the $\\delta_{LT}$ moment, which thus far was not reproducible for proton and neutron simultaneously in chiral perturbation theory. This problem, known as the "$\\delta_{LT}$ puzzle," is not seen in the present calculation.
Baryonic forces and hyperons in nuclear matter from SU(3) chiral effective field theory
Petschauer, Stefan Karl
2016-02-12
In this work the baryon-baryon interaction is studied at next-to-leading order in SU(3) chiral effective field theory and applied to hyperon-nucleon scattering. The properties of hyperons in isospin-symmetric as well as asymmetric nuclear matter are calculated within the Bruecker-Hartree-Fock formalism. Moreover, the leading three-baryon interaction is derived and its low-energy constants are estimated from decuplet intermediate states. We conclude, that chiral effective field theory is a well-suited tool to describe the baryonic forces.
A gauge invariant chiral unitary framework for kaon photo- and electroproduction on the proton
Borasoy, B; Meißner, Ulf-G; Nißler, R
2007-01-01
We present a gauge invariant approach to photoproduction of mesons on nucleons within a chiral unitary framework. The interaction kernel for meson-baryon scattering is derived from the chiral effective Lagrangian and iterated in a Bethe-Salpeter equation. Within the leading order approximation to the interaction kernel, data on kaon photoproduction from SAPHIR, CLAS and CBELSA/TAPS are analyzed in the threshold region. The importance of gauge invariance and the precision of various approximations in the interaction kernel utilized in earlier works are discussed.
Applying the Density Matrix Expansion with Coordinate-Space Chiral Interactions
Dyhdalo, A; Furnstahl, R J
2016-01-01
We apply the density matrix expansion (DME) at Hartree-Fock level with long-range chiral effective field theory interactions defined in coordinate space up to next-to-next-to-leading order. We consider chiral potentials both with and without explicit Delta isobars. The challenging algebra associated with applying the DME to three-nucleon forces is tamed using a new organization scheme, which will also facilitate generalizations. We include local regulators on the interactions to mitigate the effects of singular potentials on the DME couplings and simplify the optimization of generalized Skyrme-like functionals.
Heavy-Light Semileptonic Decays in Staggered Chiral Perturbation Theory
Aubin, C
2007-01-01
We calculate the form factors for the semileptonic decays of heavy-light pseudoscalar mesons in partially quenched staggered chiral perturbation theory (\\schpt), working to leading order in $1/m_Q$, where $m_Q$ is the heavy quark mass. We take the light meson in the final state to be a pseudoscalar corresponding to the exact chiral symmetry of staggered quarks. The treatment assumes the validity of the standard prescription for representing the staggered ``fourth root trick'' within \\schpt by insertions of factors of 1/4 for each sea quark loop. Our calculation is based on an existing partially quenched continuum chiral perturbation theory calculation with degenerate sea quarks by Becirevic, Prelovsek and Zupan, which we generalize to the staggered (and non-degenerate) case. As a by-product, we obtain the continuum partially quenched results with non-degenerate sea quarks. We analyze the effects of non-leading chiral terms, and find a relation among the coefficients governing the analytic valence mass depende...
Chiral anomalies and differential geometry
Zumino, B.
1983-10-01
Some properties of chiral anomalies are described from a geometric point of view. Topics include chiral anomalies and differential forms, transformation properties of the anomalies, identification and use of the anomalies, and normalization of the anomalies. 22 references. (WHK)
Superconductivity in a chiral nanotube
Qin, F.; Shi, W.; Ideue, T.; Yoshida, M.; Zak, A.; Tenne, R.; Kikitsu, T.; Inoue, D.; Hashizume, D.; Iwasa, Y.
2017-02-01
Chirality of materials are known to affect optical, magnetic and electric properties, causing a variety of nontrivial phenomena such as circular dichiroism for chiral molecules, magnetic Skyrmions in chiral magnets and nonreciprocal carrier transport in chiral conductors. On the other hand, effect of chirality on superconducting transport has not been known. Here we report the nonreciprocity of superconductivity--unambiguous evidence of superconductivity reflecting chiral structure in which the forward and backward supercurrent flows are not equivalent because of inversion symmetry breaking. Such superconductivity is realized via ionic gating in individual chiral nanotubes of tungsten disulfide. The nonreciprocal signal is significantly enhanced in the superconducting state, being associated with unprecedented quantum Little-Parks oscillations originating from the interference of supercurrent along the circumference of the nanotube. The present results indicate that the nonreciprocity is a viable approach toward the superconductors with chiral or noncentrosymmetric structures.
Deuteron properties from muonic atom spectroscopy
Kelkar, N. G.; Bedoya Fierro, D.
2017-09-01
Leading order (α4) finite size corrections in muonic deuterium are evaluated within a few body formalism for the μ- pn system in muonic deuterium and found to be sensitive to the input of the deuteron wave function. We show that this sensitivity, taken along with the precise deuteron charge radius determined from muonic atom spectroscopy can be used to determine the elusive deuteron D-state probability, PD, for a given model of the nucleon-nucleon (NN) potential. The radius calculated with a PD of 4.3% in the chiral NN models and about 5.7% in the high precision NN potentials is favoured most by the μ- d data.
Infrared extrapolations for atomic nuclei
Furnstahl, R J; Papenbrock, T; Wendt, K A
2014-01-01
Harmonic oscillator model-space truncations introduce systematic errors to the calculation of binding energies and other observables. We identify the relevant infrared scaling variable and give values for this nucleus-dependent quantity. We consider isotopes of oxygen computed with the coupled-cluster method from chiral nucleon-nucleon interactions at next-to-next-to-leading order and show that the infrared component of the error is sufficiently understood to permit controlled extrapolations. By employing oscillator spaces with relatively large frequencies, well above the energy minimum, the ultraviolet corrections can be suppressed while infrared extrapolations over tens of MeVs are accurate for ground-state energies. However, robust uncertainty quantification for extrapolated quantities that fully accounts for systematic errors is not yet developed.
Chiral Synthons in Pesticide Syntheses
Feringa, Bernard
1988-01-01
The use of chiral synthons in the preparation of enantiomerically pure pesticides is described in this chapter. Several routes to chiral synthons based on asymmetric synthesis or on natural products are illustrated. Important sources of chiral building blocks are reviewed. Furthermore the implicatio
Chiral fermions on the lattice
Jahn, O; Jahn, Oliver; Pawlowski, Jan M.
2002-01-01
We discuss topological obstructions to putting chiral fermions on an even dimensional lattice. The setting includes Ginsparg-Wilson fermions, but is more general. We prove a theorem which relates the total chirality to the difference of generalised winding numbers of chiral projection operators. For an odd number of Weyl fermions this implies that particles and anti-particles live in topologically different spaces.
Lodahl, Peter; Stobbe, Søren; Schneeweiss, Philipp; Volz, Jürgen; Rauschenbeutel, Arno; Pichler, Hannes; Zoller, Peter
2016-01-01
At the most fundamental level, the interaction between light and matter is manifested by the emission and absorption of single photons by single quantum emitters. Controlling light--matter interaction is the basis for diverse applications ranging from light technology to quantum--information processing. Many of these applications are nowadays based on photonic nanostructures strongly benefitting from their scalability and integrability. The confinement of light in such nanostructures imposes an inherent link between the local polarization and propagation direction of light. This leads to {\\em chiral light--matter interaction}, i.e., the emission and absorption of photons depend on the propagation direction and local polarization of light as well as the polarization of the emitter transition. The burgeoning research field of {\\em chiral quantum optics} offers fundamentally new functionalities and applications both for single emitters and ensembles thereof. For instance, a chiral light--matter interface enables...
Doped Chiral Polymer Metamaterials
Park, Cheol (Inventor); Kang, Jin Ho (Inventor); Gordon, Keith L. (Inventor); Sauti, Godfrey (Inventor); Lowther, Sharon E. (Inventor); Bryant, Robert G. (Inventor)
2017-01-01
Some implementations provide a composite material that includes a first material and a second material. In some implementations, the composite material is a metamaterial. The first material includes a chiral polymer (e.g., crystalline chiral helical polymer, poly-.gamma.-benzyl-L-glutamate (PBLG), poly-L-lactic acid (PLA), polypeptide, and/or polyacetylene). The second material is within the chiral polymer. The first material and the second material are configured to provide an effective index of refraction value for the composite material of 1 or less. In some implementations, the effective index of refraction value for the composite material is negative. In some implementations, the effective index of refraction value for the composite material of 1 or less is at least in a wavelength of one of at least a visible spectrum, an infrared spectrum, a microwave spectrum, and/or an ultraviolet spectrum.
Testa, B; Reist, M; Carrupt, P A
2000-07-01
The two enantiomers of a chiral drug may have vastly different pharmacodynamic and pharmacokinetic properties. As a result, the research and development of chiral drugs raises specific problems some of which are discussed here. Thus, various pharmacokinetic interactions may involve two enantiomers, as seen for example when one enantiomer inhibits the metabolism of the other and modifies its effects. A different situation occurs when a third compound stereoselectively inhibits the metabolism of one of the two enantiomers. Another problem examined here results from the lack of configurational stability of some chiral drugs, a little known phenomenon whose consequences can be of pharmacological or pharmaceutical significance depending on the rate of the reaction of racemization or epimerisation. In-depth investigations are needed before choosing between a eutomer or a racemate.
H Weigel
2003-11-01
In this talk I review studies of hadron properties in bosonized chiral quark models for the quark ﬂavor dynamics. Mesons are constructed from Bethe–Salpeter equations and baryons emerge as chiral solitons. Such models require regularization and I show that the two-fold Pauli–Villars regularization scheme not only fully regularizes the effective action but also leads the scaling laws for structure functions. For the nucleon structure functions the present approach serves to determine the regularization prescription for structure functions whose leading moments are not given by matrix elements of local operators. Some numerical results are presented for the spin structure functions.
Kojo, Toru; Fukushima, Kenji; McLerran, Larry; Pisarski, Robert D
2011-01-01
We elaborate how to construct the interweaving chiral spirals in (2+1) dimensions, that is defined as a superposition of differently oriented chiral spirals. We divide the two-dimensional Fermi sea into distinct wedges characterized by the opening angle 2 Theta and the depth Q \\simeq pF, where pF is the Fermi momentum. Each wedge earns an energy gain by forming a single chiral spiral. The optimal values for Theta and Q are chosen by the balance between this energy gain and the energy costs from the deformed Fermi surface (dominant at large Theta) and patch-patch interactions (dominant at small Theta). We estimate these energy gains and costs by means of the expansions in terms of 1/Nc, Lambda_QCD/Q, and Theta using a non-local four-Fermi interaction model: At small 1/Nc the mass gap (chiral condensate) is large enough and the interaction among quarks and the condensate is local in momentum space thanks to the form factor in our non-local model. The fact that patch-patch interactions lie only near the patch bo...
Rossi, P; Rossi, Paolo; Tan, Chung I
1995-01-01
Principal chiral models on a d-1 dimensional simplex are introduced and studied analytically in the large N limit. The d = 0 , 2, 4 and \\infty models are explicitly solved. Relationship with standard lattice models and with few-matrix systems in the double scaling limit are discussed.
Chiral magnetic effect without chirality source in asymmetric Weyl semimetals
Kharzeev, Dmitri; Meyer, Rene
2016-01-01
We describe a new type of the Chiral Magnetic Effect (CME) that should occur in Weyl semimetals with an asymmetry in the dispersion relations of the left- and right-handed chiral Weyl fermions. In such materials, time-dependent pumping of electrons from a non-chiral external source generates a non-vanishing chiral chemical potential. This is due to the different capacities of the left- and right-handed (LH and RH) chiral Weyl cones arising from the difference in the density of states in the LH and RH cones. The chiral chemical potential then generates, via the chiral anomaly, a current along the direction of an applied magnetic field even in the absence of an external electric field. The source of chirality imbalance in this new setup is thus due to the band structure of the system and the presence of (non-chiral) electron source, and not due to the parallel electric and magnetic fields. We illustrate the effect by an argument based on the effective field theory, and by the chiral kinetic theory calculation f...
van Deurzen, H; Luisoni, G; Mastrolia, P; Mirabella, E; Ossola, G; Peraro, T
2013-10-25
We present the calculation of the cross section for Higgs boson production in association with a top quark pair plus one jet, at next-to-leading-order accuracy in QCD. All mass dependence is retained without recurring to any approximation. After including the complete next-to-leading-order QCD corrections, we observe a strong reduction in the scale dependence of the result. We also show distributions for the invariant mass of the top quark pair, with and without the additional jet, and for the transverse momentum and the pseudorapidity of the Higgs boson. Results for the virtual contributions are obtained with a novel reduction approach based on integrand decomposition via the Laurent expansion, as implemented in the library, NINJA. Cross sections and differential distributions are obtained with an automated setup which combines the GOSAM and SHERPA frameworks.
Bevilacqua, G; Hartanto, H B; Kraus, M; Worek, M
2016-02-05
We present a complete description of top quark pair production in association with a jet in the dilepton channel. Our calculation is accurate to next-to-leading order (NLO) in QCD and includes all nonresonant diagrams, interferences, and off-shell effects of the top quark. Moreover, nonresonant and off-shell effects due to the finite W gauge boson width are taken into account. This calculation constitutes the first fully realistic NLO computation for top quark pair production with a final state jet in hadronic collisions. Numerical results for differential distributions as well as total cross sections are presented for the Large Hadron Collider at 8 TeV. With our inclusive cuts, NLO predictions reduce the unphysical scale dependence by more than a factor of 3 and lower the total rate by about 13% compared to leading-order QCD predictions. In addition, the size of the top quark off-shell effects is estimated to be below 2%.
U Jamil; J K Sarma
2008-09-01
Evolution of gluon distribution function from Dokshitzer–Gribov–Lipatov–Altarelli–Parisi (DGLAP) evolution equation in next-to-leading order (NLO) at low- is presented assuming the Regge behaviour of quark and gluon at this limit. We compare our results of gluon distribution function with MRST2004, GRV98LO and GRV98NLO parametrizations and show the compatibility of Regge behaviour of quark and gluon distribution functions with perturbative quantum chromodynamics (PQCD) at low-.
Kniehl, B.A.; Kotikov, A.V.; Merebashvili, Z.V.; Veretin, O.L. [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik
2009-05-15
We consider the production of heavy-quark pairs in the collisions of polarized and unpolarized on-shell photons and present, in analytic form, the fully integrated total cross sections for total photon spins J{sub z}=0,{+-}2 at next-to-leading-order in QCD. Phenomenological applications include b anti b production, which represents an irreducible background to standard-model intermediate-mass Higgs-boson production, as well as t anti t production. (orig.)
Detecting the chirality for coupled quantum dots
Cao Huijuan [Institute for Condensed Matter Physics, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510631 (China); Hu Lian [Institute for Condensed Matter Physics, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510631 (China)], E-mail: huliancaohj@yahoo.com
2008-04-21
We propose a scheme to detect the chirality for a system consisting of three coupled quantum dots. The chirality is found to be determined by the frequency of the transition between chiral states under the chiral symmetry broken perturbation. The results are important to construct quantum gates and to demonstrate chiral entangle states in the triangle spin dots.
Chiral three-nucleon force at N^4LO II: Intermediate-range contributions
Krebs, Hermann; Epelbaum, Evgeny
2013-01-01
We derive the subleading contributions to the two-pion-one-pion exchange and ring three-nucleon force topologies emerging at next-to-next-to-next-to-next-to-leading order in chiral effective field theory. The resulting expressions do not involve any unknown parameters. To study convergence of the chiral expansion we work out the most general operator structure of a local isospin-invariant three-nucleon force. Using the resulting operator basis with 22 independent structures, we compare the strength of the corresponding potentials in configuration space for individual topologies at various orders in the chiral expansion. As expected, the subleading contributions from the two-pion-one-pion-exchange and ring diagrams are large which can be understood in terms of intermediate excitation of the Delta(1232) isobar.
Chiral Corrections to Nucleon Two- and Three-Point Correlation Functions
Tiburzi, Brian C
2015-01-01
We consider multi-particle contributions to nucleon two- and three-point functions from the perspective of chiral dynamics. Lattice nucleon interpolating operators, which have definite chiral transformation properties, can be mapped into chiral perturbation theory. Using the most common of such operators, we determine pion-nucleon and pion-delta couplings to nucleon two- and three-point correlation functions at leading order in the low-energy expansion. The couplings of pions to nucleons and deltas in two-point functions are consistent with simple phase-space considerations, in accordance with the Lehmann spectral representation. An argument based on available phase space on a torus is utilized to derive the scaling of multiple-pion couplings. While multi-pion states are indeed suppressed, this suppression scales differently with particle number compared to that in infinite volume. For nucleon three-point correlation functions, we investigate the axial-vector current at vanishing momentum transfer. The effect...
Neutron matter from chiral two- and three-nucleon calculations up to N$^3$LO
Drischler, C; Hebeler, K; Schwenk, A
2016-01-01
Neutron matter is an ideal laboratory for nuclear interactions derived from chiral effective field theory since all contributions are predicted up to next-to-next-to-next-to-leading order (N$^3$LO) in the chiral expansion. By making use of recent advances in the partial-wave decomposition of three- nucleon (3N) forces, we include for the first time N$^3$LO 3N interactions in many-body perturbation theory (MBPT) up to third order and in self-consistent Green's function theory (SCGF). Using these two complementary many-body frameworks we provide improved predictions for the equation of state of neutron matter at zero temperature and also analyze systematically the many-body convergence for different chiral EFT interactions. Furthermore, we present an extension of the normal-ordering framework to finite temperatures. These developments open the way to improved calculations of neutron-rich matter including estimates of theoretical uncertainties for astrophysical applications.
Soldering Chiralities; 2, Non-Abelian Case
Wotzasek, C
1996-01-01
We study the non-abelian extension of the soldering process of two chiral WZW models of opposite chiralities, resulting in a (non-chiral) WZW model living in a 2D space-time with non trivial Riemanian curvature.
Spiral Galaxies as Chiral Objects?
Capozziello, S; Capozziello, Salvatore; Lattanzi, Alessandra
2005-01-01
Spiral galaxies show axial symmetry and an intrinsic 2D-chirality. Environmental effects can influence the chirality of originally isolated stellar systems and a progressive loss of chirality can be recognised in the Hubble sequence. We point out a preferential modality for genetic galaxies as in microscopic systems like aminoacids, sugars or neutrinos. This feature could be the remnant of a primordial symmetry breaking characterizing systems at all scales.
Ahmed, Mohammad W.; Gao, Haiyan; Weller, Henry R.; Holstein, Barry
2007-10-01
pt. A. Plenary session. Opening remarks: experimental tests of chiral symmetry breaking / A. M. Bernstein. [Double pie symbols] scattering / H. Leutwyler. Chiral effective field theory in a [Triangle]-resonance region / V. Pascalutsa. Some recent developments in chiral perturbation theory / Ulf-G. Mei ner. Chiral extrapolation and nucleon structure from the lattice / R.D. Young. Recent results from HAPPEX / R. Michaels. Chiral symmetries and low energy searches for new physics / M.J. Ramsey-Musolf. Kaon physics: recent experimental progress / M. Moulson. Status of the Cabibbo angle / V. Cirigliano. Lattice QCD and nucleon spin structure / J.W. Negele. Spin sum rules and polarizabilities: results from Jefferson lab / J-P Chen. Compton scattering and nucleon polarisabilities / Judith A. McGovern. Virtual compton scattering at MIT-bates / R. Miskimen. Physics results from the BLAST detector at the BATES accelerator / R.P. Redwine. The [Pie sympbol]NN system, recent progress / C. Hanhart. Application of chiral nuclear forces to light nuclei / A. Nogga. New results on few-body experiments at low energy / Y. Nagai. Few-body lattice calculations / M.J. Savage. Research opportunities at the upgraded HI?S facility / H.R. Weller -- pt. B. Goldstone boson dynamics. Working group summary: Goldstone Boson dynamics / G. Colangelo and S. Giovannella. Recent results on radiative Kaon decays from NA48 and NA48/2 / S.G. López. Cusps in K-->3 [Pie symbol] decays / B. Kubis. Recent KTeV results on radiative Kaon decays / M.C. Ronquest. The [Double pie symbols] scattering amplitude / J.R. Peláez. Determination of the Regge parameters in the [Double pie symbols] scattering amplitude / I. Caprini. e+e- Hadronic cross section measurement at DA[symbol]NE with the KLOE detector / P. Beltrame. Measurement of the form factors of e+e- -->2([Pie symbol]+[Pie symbol]-), pp and the resonant parameters of the heavy charmonia at BES / H. Hu. Measurement of e+e- multihadronic cross section below 4
Chiral Biomarkers in Meteorites
Hoover, Richard B.
2010-01-01
The chirality of organic molecules with the asymmetric location of group radicals was discovered in 1848 by Louis Pasteur during his investigations of the rotation of the plane of polarization of light by crystals of sodium ammonium paratartrate. It is well established that the amino acids in proteins are exclusively Levorotary (L-aminos) and the sugars in DNA and RNA are Dextrorotary (D-sugars). This phenomenon of homochirality of biological polymers is a fundamental property of all life known on Earth. Furthermore, abiotic production mechanisms typically yield recemic mixtures (i.e. equal amounts of the two enantiomers). When amino acids were first detected in carbonaceous meteorites, it was concluded that they were racemates. This conclusion was taken as evidence that they were extraterrestrial and produced by abiologically. Subsequent studies by numerous researchers have revealed that many of the amino acids in carbonaceous meteorites exhibit a significant L-excess. The observed chirality is much greater than that produced by any currently known abiotic processes (e.g. Linearly polarized light from neutron stars; Circularly polarized ultraviolet light from faint stars; optically active quartz powders; inclusion polymerization in clay minerals; Vester-Ulbricht hypothesis of parity violations, etc.). This paper compares the measured chirality detected in the amino acids of carbonaceous meteorites with the effect of these diverse abiotic processes. IT is concluded that the levels observed are inconsistent with post-arrival biological contamination or with any of the currently known abiotic production mechanisms. However, they are consistent with ancient biological processes on the meteorite parent body. This paper will consider these chiral biomarkers in view of the detection of possible microfossils found in the Orgueil and Murchison carbonaceous meteorites. Energy dispersive x-ray spectroscopy (EDS) data obtained on these morphological biomarkers will be
Neutrinoless double beta decay and chiral SU(3)
Cirigliano, V.; Dekens, W.; Graesser, M.; Mereghetti, E.
2017-06-01
TeV-scale lepton number violation can affect neutrinoless double beta decay through dimension-9 ΔL = ΔI = 2 operators involving two electrons and four quarks. Since the dominant effects within a nucleus are expected to arise from pion exchange, the π- →π+ ee matrix elements of the dimension-9 operators are a key hadronic input. In this letter we provide estimates for the π- →π+ matrix elements of all Lorentz scalar ΔI = 2 four-quark operators relevant to the study of TeV-scale lepton number violation. The analysis is based on chiral SU (3) symmetry, which relates the π- →π+ matrix elements of the ΔI = 2 operators to the K0 →Kbar0 and K → ππ matrix elements of their ΔS = 2 and ΔS = 1 chiral partners, for which lattice QCD input is available. The inclusion of next-to-leading order chiral loop corrections to all symmetry relations used in the analysis makes our results robust at the 30% level or better, depending on the operator.