Search results for "Condensate"
showing 10 items of 208 documents
Readout of quantum information spreading using a disordered quantum walk
2021
We design a quantum probing protocol using quantum walks to investigate the quantum information spreading pattern. We employ quantum Fisher information as a figure of merit to quantify extractable information about an unknown parameter encoded within the quantum walk evolution. Although the approach is universal, we focus on the coherent static and dynamic disorder to investigate anomalous and classical transport as well as Anderson localization. We provide a feasible experimental strategy to implement, in principle, the quantum probing protocol based on the quantum Fisher information using a Mach–Zehnder-like interferometric setup. Our results show that a quantum walk can be considered as …
Power-law running of the effective gluon mass
2007
The dynamically generated effective gluon mass is known to depend non-trivially on the momentum, decreasing sufficiently fast in the deep ultraviolet, in order for the renormalizability of QCD to be preserved. General arguments based on the analogy with the constituent quark masses, as well as explicit calculations using the operator-product expansion, suggest that the gluon mass falls off as the inverse square of the momentum, relating it to the gauge-invariant gluon condensate of dimension four. In this article we demonstrate that the power-law running of the effective gluon mass is indeed dynamically realized at the level of the non-perturbative Schwinger-Dyson equation. We study a gauge…
Predictions for low-pTand high-pThadron spectra in nearly central Pb+Pb collisions atsNN=5.5TeV tested atsNN=130and 200 GeV
2005
We study the hadron spectra in nearly central $A+A$ collisions at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) in a broad transverse momentum range. We cover the low-${p}_{T}$ spectra using longitudinally boost-invariant hydrodynamics with initial energy and net-baryon number densities from the perturbative QCD (pQCD)+saturation model. Buildup of the transverse flow and sensitivity of the spectra to a single decoupling temperature ${T}_{\mathrm{dec}}$ are studied. Comparison with RHIC data at $\sqrt{{s}_{\mathit{NN}}}=130$ and 200 GeV suggests a rather high value ${T}_{\mathrm{dec}}=150$ MeV. The high-${p}_{T}$ spectra are computed using factorized pQCD cro…
Forward J / ψ and D meson nuclear suppression at the LHC
2017
Abstract Using the color glass condensate formalism, we study the nuclear modification of forward J/ψ and D meson production in high energy proton-nucleus collisions at the LHC. We show that relying on the optical Glauber model to obtain the dipole cross section of the nucleus from the one of the proton fitted to HERA DIS data leads to a smaller nuclear suppression than in the first study of these processes in this formalism and a better agreement with experimental data.
Renormalization group evolution of multi-gluon correlators in high energy QCD
2011
Many-body QCD in leading high energy Regge asymptotics is described by the Balitsky-JIMWLK hierarchy of renormalization group equations for the x evolution of multi-point Wilson line correlators. These correlators are universal and ubiquitous in final states in deeply inelastic scattering and hadronic collisions. For instance, recently measured di-hadron correlations at forward rapidity in deuteron-gold collisions at the Relativistic Heavy Ion Collider (RHIC) are sensitive to four and six point correlators of Wilson lines in the small x color fields of the dense nuclear target. We evaluate these correlators numerically by solving the functional Langevin equation that describes the Balitsky-…
Helicity fractions of W bosons from top quark decays
2008
The helicity fractions of the W boson from top quark decays have been determined by the CDF and D0 collaborations at the Tevatron. It is to be expected that the present experimental errors will decrease with larger data samples and in particular with measurements at the LHC. These improvements have to be matched by advances on the theoretical side. In this presentation we present a progress report on the calculation of the next-to-next-to-leading order QCD corrections to the decay width of the top quark into polarised W bosons.
Light Quark Yukawa Couplings and the W ± h Charge Asymmetry
2017
Abstract I review the recent theory progress on possibly measuring the light quark couplings, emphasizing the distinction between direct and indirect measurements. I highlight the importance of the W ± h charge asymmetry measurement as a direct probe of enhanced light quark Yukawa couplings. I propose the W ± h → l ± l ± q q ′ ν ν final state as a promising channel for measuring the charge asymmetry. This clean, same-sign dilepton final state should reach statistical discovery sensitivity in each W ± h charge mode with 300 fb -1 of Large Hadron Collider luminosity, and affords an impressive sub-percent statistical accuracy with the anticipated 3 ab -1 high luminosity upgrade. After accounti…
Search for admixture of scalar top quarks in the tt¯ lepton + jets final state at s=1.96 TeV
2009
A search for pair production of the lightest supersymmetric partner of the top quark is performed in the lepton+jets channel using 0.9 fb-1 of data collected by the D0 experiment. Kinematic differences between scalar top quark pair production and the dominant top quark pair production background are used to separate the two processes. First limits from Run II of the Fermilab Tevatron Collider for the scalar top quark decaying to a chargino and a b quark are obtained for scalar top quark masses of 130-190 GeV and chargino masses of 90-150 GeV.
Unitarity constraints on top quark signatures of Higgsless models
2005
We use conditions for unitarity cancellations to constrain the couplings of the top and bottom quarks to Kaluza-Klein modes in Higgsless models of electroweak symmetry breaking. An example for the mass spectrum of quark resonances in a theory space model is given and the implications for the collider phenomenology in the top sector are discussed, comparing to signatures of Little Higgs and strong electroweak symmetry breaking models.
Forward quark jet-nucleus scattering in a light-front Hamiltonian approach
2020
We investigate the scattering of a quark jet on a high-energy heavy nucleus using the time-dependent light-front Hamiltonian approach. We simulate a real-time evolution of the quark in a strong classical color field of the relativistic nucleus, described as the Color Glass Condensate. We study the sub-eikonal effect by letting the quark jet carry realistic finite longitudinal momenta, and we find sizeable changes on the transverse coordinate distribution of the quark. We also observe the energy loss of the quark through gluon emissions in the $\ket{q}+\ket{qg}$ Fock space. This approach provides us with an opportunity to study scattering processes from non-perturbative aspects.