18,624,219 research outputs found
D=11, p=5
The equations of motion of the super five-brane in D=11 dimensions are
derived using the formalism of superembeddings. The equations describe highly
nonlinear self-interactions of a tensor multiplet in the six dimensional
worlsurface, and they have manifest worldsurface local supersymmetry. The
geometry of the target space corresponds to D=11 supergravity.Comment: 7 pages, late
Rescattering effects in B_{u,d,s}(bar) to D P, D(bar) P decays
We study quasi-elastic rescattering effects in B_{u,d,s}(bar) to DP, D(bar)P
decays, where P is a light pseudoscalar. The updated measurements of
B_{u,d}(bar) to DP decays are used to extract the effective Wilson coefficients
a^{eff}_1 ~ 0.90, a^{eff}_2 ~ 0.23, three strong phases delta ~ 53 degree,
theta ~ 18 degree, sigma ~ -88 degree, and the mixing angle tau ~ 9 degree.
This information is used to predict rates of nineteen B_{s}(bar) to DP and
B_{u,d,s}(bar) to D(bar)P decay modes, including modes of interests in the
gamma/phi_3 program. Many decay rates are found to be enhanced. In particular,
the B_s(bar) to D0 K0 rate is predicted to be 8\times 10^{-4}, which could be
measured soon. The rescattering effects on the corresponding B_{u,d,s}(bar) to
D(bar)P, DP amplitude ratios r_B, r_{B_s}, and the relative strong phases
delta_B, delta_{B_s} are studied. Although the decay rates are enhanced in most
cases, r_{B,B_s} values are similar to factorization expectation.Comment: 16 page
Observation and study of baryonic B decays: B -> D(*) p pbar, D(*) p pbar pi, and D(*) p pbar pi pi
We present a study of ten B-meson decays to a D(*), a proton-antiproton pair,
and a system of up to two pions using BaBar's data set of 455x10^6 BBbar pairs.
Four of the modes (B0bar -> D0 p anti-p, B0bar -> D*0 p anti-p, B0bar -> D+ p
anti-p pi-, B0bar -> D*+ p anti-p pi-) are studied with improved statistics
compared to previous measurements; six of the modes (B- -> D0 p anti-p pi-, B-
-> D*0 p anti-p pi-, B0bar -> D0 p anti-p pi- pi+, B0bar -> D*0 p anti-p pi-
pi+, B- -> D+ p anti-p pi- pi-, B- -> D*+ p anti-p pi- pi-) are first
observations. The branching fractions for 3- and 5-body decays are suppressed
compared to 4-body decays. Kinematic distributions for 3-body decays show
non-overlapping threshold enhancements in m(p anti-p) and m(D(*)0 p) in the
Dalitz plots. For 4-body decays, m(p pi-) mass projections show a narrow peak
with mass and full width of (1497.4 +- 3.0 +- 0.9) MeV/c2, and (47 +- 12 +- 4)
MeV/c2, respectively, where the first (second) errors are statistical
(systematic). For 5-body decays, mass projections are similar to phase space
expectations. All results are preliminary.Comment: 28 pages, 90 postscript figures, submitted to LP0
The p(d,p)d and p(d,p)pn reactions as a tool for the study of the short range internal structure of the deuteron
In recent time the deuteron structure at short distances is often treated
from the point of view nonnucleonic degrees of freedom. In this paper the
measurements of T-odd polarization observables using tensor polarized deuteron
beam and polarized proton target or proton polarimeter are proposed to search
the quark configurations inside the deuteron.Comment: 12 pages, 8 Postscript figures, submitted in Phys.Atom.Nuc
The reactions p + n --> d + omega and p + n --> d + phi near threshold
The reactions p+n-->d+omega and p+n-->d+phi are studied within a relativistic
meson-exchange model of hadronic interactions. Predictions for the total cross
sections and for the angular distributions of the vector mesons are presented.
The resulting cross sections near threshold are around 10 - 30 microb for
p+n-->d+omega$ and 200 - 250 nb for p+n-->d+phi. A moderate deviation of the
cross section ratio sigma_{p+n-->d+phi} / sigma_{p+n-->d+omega} from that of
the Okubo-Zweig-Iizuka rule is predicted.Comment: 12 pages, 7 figure
Noncommutative and Ordinary Super Yang-Mills on (D, D) Bound States
We study properties of (D, D) nonthreshold bound states () in the dual gravity description. These bound states can be viewed as
D-branes with a nonzero NS field of rank two. We find that in the
decoupling limit, the thermodynamics of the coincident D-branes with
field is the same not only as that of coincident D-branes without
field, but also as that of the coincident D-branes with
two smeared coordinates and no field, for with being the area of the two
smeared directions and a noncommutativity parameter. We also obtain
the same relation from the thermodynamics and dynamics by probe methods. This
suggests that the noncommutative super Yang-Mills with gauge group in
() dimensions is equivalent to an ordinary one with gauge group
in () dimensions in the limit . We
also find that the free energy of a D-brane probe with field in the
background of D-branes with field coincides with that of a D-brane
probe in the background of D-branes without field.Comment: 28 pages, Latex, references added, to appear in JHE
(1 + p)-Dimensional Open D(p - 2) Brane Theories
The dynamics of a Dp brane can be described either by an open string ending
on this brane or by an open D(p - 2) brane ending on the same Dp brane. The
ends of the open string couple to a Dp brane worldvolume gauge field while the
boundary of the open D(p - 2) brane couples to a (p - 2)-form worldvolume
potential whose field strength is Poincare dual to that of the gauge field on
the Dp-brane worldvolume. With this in mind, we find that the Poincare dual of
the fixed rank-2 magnetic field used in defining a (1 + p)-dimensional
noncommutative Yang-Mills (NCYM) gives precisely a near-critical electric field
for the open D(p - 2) brane. We therefore find (1 + p)-dimensional open D(p -
2) brane theories along the same line as for obtaining noncommutative open
string theories (NCOS), OM theory and open Dp brane theories (ODp) from NS5
brane. Similarly, the Poincare dual of the near-critical electric field used in
defining a (1 + p)-dimensional NCOS gives a fixed magnetic-like field. This
field along with the same bulk field scalings defines a (1 + p)-dimensional
noncommutative field theory. In the same spirit, we can have various (1 +
5)-dimensional noncommutative field theories resulting from the existence of
ODp if the description of open D(4 - p) brane ending on the NS5 brane is
insisted.Comment: 35 pages, references added and discussion on decoupled field theories
refine
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