118534772
Towards multi-field D-brane inflation in a warped throat
We study the inflationary dynamics in a model of slow-roll inflation in warped throat. Inflation is realized by the motion of a D-brane along the radial direction of the throat, and at later stages instabilities develop in the angular directions. We closely investigate both the single field potential relevant for the slow-roll phase, and the full multi-field one including the angular modes which becomes important at later stages. We study the main features of the instability process, discussing its possible consequences and identifying the vacua towards which the angular modes are driven.
17995666
On the scattering of magnon boundstates
We study the scattering of magnon boundstates in the spin-chain description of planar = 4 SUSY Yang-Mills. Starting from the conjectured exact S-matrix for magnons in the SU(2) sector, we calculate the corresponding S-matrix for boundstates with an arbitrary number of constituent magnons. The resulting expression has an interesting analytic structure with both simple and double poles. We also calculate the semiclassical S-matrix for the scattering of the corresponding excitations on the string worldsheet known as Dyonic Giant Magnons. We find precise agreement with the magnon boundstate S-matrix in the limit of large 't Hooft coupling.
17544914
Precision test of AdS/CFT in Lunin-Maldacena background
We obtain the solutions and explicitly calculate the energy for a class of two-spin semiclassical string states in the Lunin-Maldacena background. These configurations are the β-deformed versions of the folded string solutions in AdS5 × S5 background. They correspond to certain single trace operators in the = 1 superconformal β deformation of = 4 Yang-Mills. We calculate the one loop anomalous dimension for the dual single trace operators from the associated twisted spin chain with a general two-cut distribution of Bethe roots. Our results show a striking match between the two calculations. We demonstrate the natural identification of parameters on the two sides of the analysis, and explain the significance of the Virasoro constraint associated with the winding motion of semiclassical strings from the perspective of the spin chain solution.
118687033
Moduli space and wall-crossing formulae in higher-rank gauge theories
A bstractWe study the interplay between wall-crossing in four-dimensional gauge theory and instanton contributions to the moduli space metric of the same theory on $\mathbb{R}^{3}\times S^{1}$. We consider $\mathcal{N}=2$ SUSY Yang-Mills with gauge group SU(n) and focus on walls of marginal stability which extend to weak coupling. By comparison with explicit field theory results we verify the Kontsevich-Soibelman formula for the change in the BPS spectrum at these walls and check the smoothness of the metric in the corresponding compactified theory. We also verify in detail the predictions for the one instanton contribution to the metric coming from the non-linear integral equations of Gaiotto, Moore and Nietzke.
10607038
Geometry and topology of bubble solutions from gauge theory
We study how geometrical and topological aspects of certain 1 -BPS type IIB supergravity solutions are captured by the N = 4 Super Yang-Mills gauge theory in the AdS/CFT context. The type IIB solutions are completely characterized by arbitrary droplets in a plane and we consider, in particular, concentric droplets. We probe the dual 1 -BPS operators of the gauge theory with single traces and extract their one-loop anomalous dimensions. The action of the one-loop dilatation operator can be reformulated as the Hamiltonian of a bosonic lattice. The operators defining the Hamiltonian encode the topology of the droplet. The axial symmetry of the droplets turns out to be essential for obtaining the spectrum of the Hamiltonians. In appropriate BMN limits, the near-BPS spectrum reproduces the spectrum of near-BPS string excitations propagating along each individual edge of the droplet of the dual geometric background. We also study semiclassical regimes for the Hamiltonians. We show that for droplets having disconnected constituents, the Hamiltonian admits different complimentary semiclassical descriptions, each one replicating the semiclassical description for closed strings extending in each of the constituents.
119213771
A 5d/3d duality from relativistic integrable system
A bstractWe propose and prove a new exact duality between the F-terms of supersymmetric gauge theories in five and three dimensions with adjoint matter fields. The theories are compactified on a circle and are subject to the Ω deformation. In the limit proposed by Nekrasov and Shatashvili, the supersymmetric vacua become isolated and are identified with the eigenstates of a quantum integrable system. The effective twisted superpotentials are the Yang-Yang functional of the relativistic elliptic Calogero-Moser model. We show that they match on-shell by deriving the Bethe ansatz equation from the saddle point of the five-dimensional partition function. We also show that the Chern-Simons terms match and extend our proposal to the elliptic quiver generalizations.
84835822
Onset of radial flow in p+p collisions
It has been debated for decades whether hadrons emerging from p+p collisions exhibit collective expansion. The signal of the collective motion in p+p collisions is not as clear as in heavy-ion collisions because of the low multiplicity and large fluctuation in p+p collisions. Tsallis Blast-Wave (TBW) model is a thermodynamic approach, introduced to handle the overwhelming correlation and fluctuation in the hadronic processes. We have systematically studied the identified particle spectra in p+p collisions from RHIC to LHC using TBW and found no appreciable radial flow in p+p collisions below √s = 900 GeV. At LHC higher energy of 7 TeV in p+p collisions, the radial flow velocity achieves an average of (β) = 0.320 ± 0.005. This flow velocity is comparable to that in peripheral (40-60%) Au+Au collisions at RHIC. In addition, breaking of the identified particle spectra mT scaling was also observed at LHC from a model independent test.
123519682
PROSPECT OF PARTICLE PHYSICS IN CHINA
The nuclear physics and particle physics researches in China have a long tradition. BEPC is a milestone of the particle physics in China. The many interesting physics results were obtained from BEPC. Beijing Synchrotron Radiation Facility based on BEPC became the major synchrotron radiation facility in China. The upgrade of BEPC, which will increase the luminosity by two orders of magnitude, is going smoothly. The nonaccelerator based experiments were promoted also. Professor Yang made very important contribution to Chinese physics, especially to promote the large science facilities for the multiple discipline researches. The particle physics faces the great challenges, and meets the great opportunities in the 21st century. The medium-term plan of the particle physics in China was discussed.
119197432
Proton decay and the origin of quark and lepton mixing
A bstractIt was recently proposed that all flavor mixing has a single source, namely the mixing of the three quark and lepton families with “extra” vectorlike fermions in 5 + $ \overline{5} $ multiplets of SU(5). This was shown to lead to several testable predictions including neutrino masses and CP-violating phases. Here it is shown that the mixing angles within grand unified fermion multiplets are also predicted. Proton decay branching ratios would thus give several independent tests of the model. Certain model parameters could be determined independently from the quark and lepton spectrum and from proton decay.
121288070
A strategy for the precision measurement of MW at the threshold of the W-pair production☆
Abstract A data-driven maximum likelihood scanning strategy (BES method), which has been successfully used to measure the τ mass, is proposed to measure M W near the threshold of the W + W − production at LEP phase II. The Monte Carlo study has shown that with about 45 pb −1 per experiment, and combining the number of W + W − events from the 4 LEP experiments, one could obtain an accuracy on M W of 77 MeV (statistical error only) with the data-driven maximum likelihood search. With the proposed luminosity at the threshold, the statistical error is dominant in the uncertainties of the measurement.
14512709
The present day mass function in the central region of the Arches cluster
We study the evolution of the mass function in young and dense star clusters by means of direct N-body simulations. Our main aim is to explain the recent observations of the relatively flat mass function observed near the centre of the Arches star cluster. In this region, the power-law index of the mass function for stars more massive than about 5–6 M⊙ is larger than the Salpeter value by about unity, whereas further out, and for the lower mass stars, the mass function resembles the Salpeter distribution. We show that the peculiarities in the Arches mass function can be explained satisfactorily without primordial mass segregation. We draw two conclusions from our simulations: (i) the Arches initial mass function is consistent with a Salpeter slope down to ∼1 M⊙, and (ii) the cluster is about half-way towards core collapse. The cores of other star clusters with characteristics similar to those of the Arches are expected to show similar flattening in the mass functions for the high-mass (≳5 M⊙) stars.