14512957
Imaginary Sources: Completeness Conjecture and Charges
While in string theory the subject of sources in imaginary time has received some attention, we demonstrate the power of imaginary sources by proving that they constitute in several field theories a complete basis for all smooth and time dependent source free solutions. These proofs promote the study of imaginary sources to a new and crucial viewpoint for understanding time dependent backgrounds. From our field theory examples we further propose a completeness conjecture that every regular solution to a field equation of motion has a corresponding imaginary source configuration. We define charges for spacelike sources and show their compatibility with the usual charge definition for timelike sources. Many new non-singular time dependent field theory solutions are discussed, including Wick rotations of abelian instantons which demonstrate a close relationship between electric-magnetic duals and analytic continuation.
8625540
Solitons in supersymmety breaking meta-stable vacua
In recently found supersymmetry-breaking meta-stable vacua of the supersymmetric QCD, we examine possible exsitence of solitons. Homotopy groups of the moduli space of the meta-stable vacua show that there is no nontrivial soliton for SU(Nc) gauge group. When U(1)B symmetry present in the theory is gauged, we find non-BPS solitonic (vortex) strings whose existence and properties are predicted from brane configurations. We obtain explicit classical solutions which reproduce the predicitions. For SO(Nc) gauge group, we find there are solitonic strings for N≡Nf−Nc+4 = 2, and Z2 strings for the other N. The strings are meta-stable as they live in the meta-stable vacua.
118661785
Holographic nuclei: supersymmetric examples
We provide a dual gravity description of a supersymmetric heavy nucleus, following the idea of our previous paper arXiv/0809.3141. The supersymmetric nucleus consists of a merginal bound state of A baryons distributed over a ball in 3 dimensions. In the gauge/string duality, the baryon in = 4 super Yang-Mills (SYM) theory corresponds to a D5-brane wrapping S5 of the AdS5×S5 spacetime, so the nucleus corresponds to a collection of A D5-branes. We take a large A and a near horizon limits of a back-reacted geometry generated by the wrapped A D5-branes, where we find a gap in the supergravity fluctuation spectrum. This spectrum is a gravity dual of giant resonances of heavy nuclei, in the supersymmetric toy example of QCD.
16844941
ADHM is tachyon condensation
We completely realize the ADHM construction of instantons in D-brane language of tachyon condensations. Every step of the construction is given a physi- cal interpretation in string theory, in a boundary state formalism valid all order in � ' . Accordingly, equivalence between Yang-Mills configurations on D4-branes and D0-branes inside the D4-branes is proven, which shows that small instanton config- urations of the Yang-Mills fields are protected against stringy � ' corrections. We provide also D-brane realizations of the inverse ADHM construction, the complete- ness, and the noncommutative ADHM construction.
119106317
Chiral magnetic effect from Q-balls
We apply a generic framework of linear sigma models for revealing a mechanism of the mysterious phenomenon, the chiral magnetic effect, in quark-gluon plasma. An electric current arises along a background magnetic field, which is given rise to by Q-balls (non-topological solitons) of the linear sigma model with axial anomaly. We find additional alternating current due to quark mass terms. The hadronic Q-balls, baby boson stars, may be created in heavy-ion collisions.
14363850
BIRTH OF CLOSED STRINGS AND DEATH OF OPEN STRINGS DURING TACHYON CONDENSATION
The tremendous progress achieved through the study of black holes and branes suggests that their time-dependent generalizations called Spacelike branes (S-branes) may prove similarly useful. An example of an established approach to S-branes is to include a string boundary interaction and we first summarize evidence for the death of open string degrees of freedom for the homogeneous rolling tachyon on a decaying brane. Then, we review how to extract the flat S-brane worldvolumes describing the homogeneous rolling tachyon and how large deformations correspond to creation of lower dimensional strings and branes. These S-brane worldvolumes are governed by S-brane actions which are on equal footing to D-brane actions, since they are derived by imposing conformality on the string worldsheet, as well as by analyzing fluctuations of time-dependent tachyon configurations. As further examples we generalize previous solutions of the S-brane actions so as to describe multiple decaying and nucleating closed fundamenta...
17561372
The static quark potential in 2+1 flavour Domain Wall QCD from QCDOC
We report our present status of on-going project on the measurement of the static quark potential in 2+1 flavour domain wall QCD with various improved gauge actions and couplings. Lattice spacing determined from Sommer scale on these ensembles are from 1.6 GeV to 2.0 GeV for $16^3 \times 32$ lattice with fifth dimension size 8. We also examine size of discretization error from scaling of a pair of dimensionless quantities, $(r_0 m_\pi)^2$ and $r_0 m_\rho$, and found small scaling violation.
118599955
Dynamical QCD simulation with theta terms
The theta term that breaks the Strong CP symmetry is introduced in the two flavors of dynamical QCD simulation. theta is analytically continued to a pure imaginary number to make the probability of Monte Carlo positive. The Neutron's Electric Dipole Moment (NEDM) is measured on the ensemble under a uniform and week electric field. Other applications of theta terms are also discussed.
119245910
Development of lattice QCD tool kit on cell broadband engine processor
Research Institute for Information Science and Education, Hiroshima University,Higashi-Hiroshima, Hiroshima, 739-8521, JapanE-mail: nakamura@riise.hiroshima-u.ac.jpWe report an implementation of a code for SU(3) matrix multiplication on Cell/B.E., which is apart of our project, Lattice Tool Kit on Cell/B.E.. On QS20, the speed of the matrix multiplicationon SPE in single precision is 227GFLOPS and it becomes 20GFLOPS together with data transferfrom main memory by DNA transfer, which is 4.6% of the hardware peak speed (460GFLOPS),and is 7.4% of the theoretical peak speed of this calculation (268.77GFLOPS). We brieﬂy describeour tuning procedure.The XXVII International Symposium on Lattice Field Theory - LAT2009July 26-31 2009Peking University, Beijing, China