H. Matsunaga

Nonlinear gauge invariance and WZW-like action for NS-NS superstring field theory

A bstractWe complete the construction of a gauge-invariant action for NS-NS superstring field theory in the large Hilbert space begun in arXiv:1305.3893 by giving a closedform expression for the action and nonlinear gauge transformations. The action has the WZW-like form and vertices are given by a pure-gauge solution of NS heterotic string field theory in the small Hilbert space of right movers.

Progress in Search for Antihelium with BESS

We have searched for antihelium nuclei in cosmic rays using the data obtained from balloon flights of the BESS magnetic spectrometer. The search was mainly based on track-quality selection, followed by rigidity analysis, and on the time-of-flight and dE/dx measurements by the scintillation counter hodoscope. We analysed all the data collected during 1993–2000 with a common analysis procedure. No antihelium nuclei events were found in the energy range from 1 to 14 GV. In order to determine a new upper limit, we have simulated the loss in the air and in the instrument of He (He) using the GEANT/GHEISHA code. Combined with the data collected in 1993 through 2000, a new 95 % confidence upper limit for the ratio of He/He at the top of the atmosphere of 6.8 × 10−7 has been obtained to be after correcting for the interactions in the air and in the instruments.

Ballooning of a thin superconducting solenoid for particle astrophysics

A thin superconducting solenoid was launched by using a large balloon up to an altitude of 36.5 km in Northern Canada in the summer of 1993 as a core facility for the cosmic ray spectrometer, BESS. The magnet was excited up to 1.0 T in persistent current mode on the ground and was launched being attended with 2.7 G shocks. After 17 hours successful flight, it was discharged on the sky and made a mild descending and landing by using a parachute for recovery. The magnet was safely operated without problems during flight in 1993 and contributed to a second observation in the summer of 1994.<<ETX>>

Notes on the Wess-Zumino-Witten-like structure: L ∞ triplet and NS-NS superstring field theory

A bstractIn the NS-NS sector of superstring field theory, there potentially exist three nilpotent generators of gauge transformations and two constraint equations: it makes the gauge algebra of type II theory somewhat complicated. In this paper, we show that every NS-NS actions have their WZW-like forms, and that a triplet of mutually commutative L∞ products completely determines the gauge structure of NS-NS superstring field theory via its WZW-like structure. We give detailed analysis about it and present its characteristic properties by focusing on two NS-NS actions proposed by [1] and [2].

On the BV formalism of open superstring field theory in the large Hilbert space

A bstractWe construct several BV master actions for open superstring field theory in the large Hilbert space. First, we show that a naive use of the conventional BV approach breaks down at the third order of the antifield number expansion, although it enables us to define a simple “string antibracket” taking the Darboux form as spacetime antibrackets. This fact implies that in the large Hilbert space, “string fields-antifields” should be reassembled to obtain master actions in a simple manner. We determine the assembly of the string anti-fields on the basis of Berkovits’ constrained BV approach, and give solutions to the master equation defined by Dirac antibrackets on the constrained string field-antifield space. It is expected that partial gauge-fixing enables us to relate superstring field theories based on the large and small Hilbert spaces directly: reassembling string fields-antifields is rather natural from this point of view. Finally, inspired by these results, we revisit the conventional BV approach and construct a BV master action based on the minimal set of string fields-antifields.