201 research outputs found
Soliton pair creation in classical wave scattering
We study classical production of soliton-antisoliton pairs from colliding
wave packets in (1+1)-dimensional scalar field model. Wave packets represent
multiparticle states in quantum theory; we characterize them by energy E and
particle number N. Sampling stochastically over the forms of wave packets, we
find the entire region in (E,N) plane which corresponds to classical creation
of soliton pairs. Particle number is parametrically large within this region
meaning that the probability of soliton-antisoliton pair production in
few-particle collisions is exponentially suppressed.Comment: 16 pages, 8 figures, journal version; misprint correcte
One Monopole with k Singularities
We present all charge one monopole solutions of the Bogomolny equation with k
prescribed Dirac singularities for the gauge groups U(2), SO(3), or SU(2). We
analyze these solutions comparing them to the previously known expressions for
the cases of one or two singularities.Comment: 12 pages, LaTe
Scalar soliton quantization with generic moduli
This article is distributed under the terms of the Creative Commons
Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in
any medium, provided the original author(s) and source are credArticle funded by SCOAP3. CP is
a Royal Society Research Fellow and partly supported by the U.S. Department of Energy
under grants DOE-SC0010008, DOE-ARRA-SC0003883 and DOE-DE-SC0007897. ABR
is supported by the Mitchell Family Foundation. We would like to thank the Mitchell
Institute at Texas A&M and the NHETC at Rutgers University respectively for hospitality
during the course of this work. We would also like to acknowledge the Aspen Center
for Physics and NSF grant 1066293 for a stimulating research environment which led to
questions addressed in this paper
The phase diagram of Yang-Mills theory with a compact extra dimension
We present a non-perturbative study of the phase diagram of SU(2) Yang-Mills
theory in a five-dimensional spacetime with a compact extra dimension. The
non-renormalizable theory is regularized on an anisotropic lattice and
investigated through numerical simulations in a regime characterized by a
hierarchy between the scale of low-energy physics, the inverse compactification
radius, and the cutoff scale. We map out the structure of the phase diagram and
the pattern of lines corresponding to fixed values of the ratio between the
mass of the fifth component of the gauge field and the non-perturbative mass
gap of the four-dimensional modes. We discuss different limits of the model,
and comment on the implications of our findings.Comment: 17 pages, 9 figure
Effect of prenatal glucocorticoid treatment on size at birth among infants born at term gestation
ObjectiveTo determine whether prenatal treatment with a single course of glucocorticoids (GCs) affects size at birth among full-term infants independent of fetal size before GC administration or exposure to preterm labor (PTL).Study designIn all, 105 full-term infants were recruited into three study groups (30 GC treated; 60 controls matched for gestational age (GA) at birth and sex; and 15 PTL controls without GC exposure). Size of the infants was estimated before treatment using two-dimensional (2D) ultrasound and by direct measurement at birth.ResultsLength, weight and head circumference at birth were smaller among GC-treated infants compared with matched controls (P's<0.01), although fetal size did not differ before treatment (P's>0.2). Exposure to PTL did not account for this effect.ConclusionsPrenatal treatment with a single course of GCs was associated with a reduction in size at birth among infants born at term gestation. This effect cannot be explained by differences in fetal size before treatment or exposure to PTL
Observation of B(s)0âJ/ÏppÂŻ decays and precision measurements of the B(s)0 masses
The first observation of the decays
B
0
(
s
)
â
J
/
Ï
p
ÂŻ
p
is reported, using proton-proton collision data corresponding to an integrated luminosity of
5.2
â
â
fb
â
1
, collected with the LHCb detector. These decays are suppressed due to limited available phase space, as well as due to Okubo-Zweig-Iizuka or Cabibbo suppression. The measured branching fractions are
B
(
B
0
â
J
/
Ï
p
ÂŻ
p
)
=
[
4.51
±
0.40
(
stat
)
±
0.44
(
syst
)
]
Ă
10
â
7
,
B
(
B
0
s
â
J
/
Ï
p
ÂŻ
p
)
=
[
3.58
±
0.19
(
stat
)
±
0.39
(
syst
)
]
Ă
10
â
6
. For the
B
0
s
meson, the result is much higher than the expected value of
O
(
10
â
9
)
. The small available phase space in these decays also allows for the most precise single measurement of both the
B
0
mass as
5279.74
±
0.30
(
stat
)
±
0.10
(
syst
)
â
â
MeV
and the
B
0
s
mass as
5366.85
±
0.19
(
stat
)
±
0.13
(
syst
)
â
â
MeV
Observation of the decay Î <sub>b</sub> <sup>0</sup> âââÏ(2S)pÏ<sup>â</sup>
International audienceThe Cabibbo-suppressed decay Î âââÏ(2S)pÏ is observed for the first time using a data sample collected by the LHCb experiment in proton-proton collisions corresponding to 1.0, 2.0 and 1.9 fb of integrated luminosity at centre-of-mass energies of 7, 8 and 13 TeV, respectively. The Ï(2S) mesons are reconstructed in the ΌΌ final state. The branching fraction with respect to that of the Î âââÏ(2S)pK decay mode is measured to b
Search for CP violation in Îb0âpKâ and Îb0âpÏâ decays
A search for CP violation in Îb0âpKâ and Îb0âpÏâ decays is presented using a sample of pp collisions collected with the LHCb detector and corresponding to an integrated luminosity of 3.0fbâ1. The CP -violating asymmetries are measured to be ACPpKâ=â0.020±0.013±0.019 and ACPpÏâ=â0.035±0.017±0.020, and their difference ACPpKââACPpÏâ=0.014±0.022±0.010, where the first uncertainties are statistical and the second systematic. These are the most precise measurements of such asymmetries to date
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