118433127
Constraints on large-extra-dimensions model through 125 GeV Higgs pair production at the LHC
Based on the analysis of 5 fb−1 of data at the LHC, the ATLAS and CMS collaborations have presented evidence for a Higgs boson with a mass in the 125 GeV range. We consider the 125 GeV neutral Higgs pair production process in the context of large-extra-dimensions (LED) model including the Kaluza–Klein (KK) excited gravitons at the LHC. We consider the standard model (SM) Higgs pair production in gluon–gluon fusion channel and pure LED effects through graviton exchange as well as their interferences. It is shown that such interferences should be included; the LED model raises the transverse momentum (Pt) and invariant mass (MHH) distributions at high scales of Pt and MHH of the Higgs pair production. By using the Higgs pair production we could set the discovery limit on the cutoff scale MS up to 6 TeV for δ=2 and 4.5 TeV for δ=6.
198142987
Permanent magnet system of alpha magnetic spectrometer
Alpha magnetic spectrometer (AMS) is the first large magndtic spectrometer in space. Its precursor flioht was completed successfully in June 1998. The key part of AMS is the permanent magnet system, which was built by the lnstitute of Electric Engineering, the institute of High Energy Physics and the Chinese Academy of Launch Vehicle Technology. This system includes a permanent magnet made of high grade NdFeB and a support structure. The unique design of the permanent magnet based on the magic ring fulfills the severe requirements on the magnetic field leakage and the dipole moment for space experiments. The permanent magnet weighs about 2 tons, and provides a geometric acceptance of 0.6 m2 · sr and an analyzing powerBL2 of 0.135 T · m2. It works up to 40°C without demagnetization. The main structure is a thin double shell, which undergoes the strong magnetic force and torque of the permanent magnet, as well as the large load during launching and landing. The permanent magnet system fulfills the requirements from AMS, and satisfies the strict safety standards of NASA.
120528491
Tau-Charm factory project at Beijing
Abstract The Tau-Charm Factory (TCF) is a proposed high luminosity e + e − collider at the threshold region of the production of τ and charm. It could provide many precision measurements and search for new phenomena in the flavor physics. IHEP, Beijing, is an ideal cite to build a TCF. The status of the feasibility study of Beijing Tau-Charm Factory (BTCF) is reported.
28336224
Search for physics beyond the standard model in events with two leptons, jets, and missing transverse momentum in pp collisions at s$$ \sqrt{s} $$ = 8 TeV
A bstractA search is presented for physics beyond the standard model in final states with two opposite-sign same-flavor leptons, jets, and missing transverse momentum. The data sample corresponds to an integrated luminosity of 19.4 fb−1 of proton-proton collisions at s$$ \sqrt{s} $$ = 8 TeV collected with the CMS detector at the CERN LHC in 2012. The analysis focuses on searches for a kinematic edge in the invariant mass distribution of the oppositesign same-flavor lepton pair and for final states with an on-shell Z boson. The observations are consistent with expectations from standard model processes and are interpreted in terms of upper limits on the production of supersymmetric particles.

120582395
The performance of an L3 hadron calorimeter prototype module with BGO
Abstract A prototype of a gas sampling uranium module of the L3 hadron calorimeter was built and subsequently tested with pion beams of energies between 4 and 20 GeV. The construction of the proportional chambers, the assembling of the module, the readout electronics, and the beam test are briefly described. The energy resolution of the calorimeter module alone was measured to be 30.5 ± 3% at 6 GeV, 21 ± 2% at 10 GeV and 18 ± 2% at 20 GeV. For the module together with a BGO crystal matrix in resolution was 29 ± 3% at 4 GeV, 21 ± 2% at 10 GeV, and 17 ± 2% at 20 GeV.
138378034
PERFORMANCES OF THE AMS-02 ELECTROMAGNETIC CALORIMETER
14247031
The shape of instantons: cross-section of supertubes and dyonic instantons
We explore the correspondence between Yang-Mills instantons and algebraic curves. The curve is defined by Higgs zero locus of dyonic instantons in 1+4 dimensional Yang-Mills-Higgs theory, and it is identified in string theory with the cross-section of supertubes connecting parallel D4-branes. To present evidence for the identification, we show that with total charges fixed, the supertube angular momentum computed from the Higgs zero locus is maximized when the locus is circular, which has been proven for the cross-section of the supertubes. This leads to a consistent dictionary between the charges in two pictures. We also consider a T-dual version of the story, identifying the profiles of the wavy instanton strings with those of the supercurves/D-helices. Based on this observation, we then argue a novel correspondence between ADHM data of instantons and algebraic curves defining the locus. The degree of the curve is related to the instanton number, and splitting property of the curve is physically manifested by well-separated instantons.
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.
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.
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.
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.