The KEDR detector Anashin, V. V.; Aulchenko, V. M.; Baldin, E. M. ...
Physics of particles and nuclei,
07/2013, Letnik:
44, Številka:
4
Journal Article
Recenzirano
The KEDR detector is a universal magnetic detector designed for studying the
c
- and
b
-quarks and two-photon physics, and is employed at the VEPP-4M
e
+
e
−
collider. A specific feature of the ...experiment is the measurement of absolute beam energy using two methods: the resonant depolarization and the faster but less precise Compton backscattering of laser photons. This allowed a large series of measurements to be performed, in which the accuracy of determination of such fundamental parameters of particles as mass and total and leptonic widths was improved.
The electronic width of the
J
/
ψ
meson and its product by the branching fractions of
J
/
ψ
meson decay to hadrons and electrons measured with the KEDR detector at the VEPP-4M
e
+
e
−
collider have ...been reported in ref. 1.
Measurement of Γee(J/ψ) with KEDR detector Anashin, V. V; Aulchenko, V. M; Baldin, E. M ...
The journal of high energy physics,
05/2018, Letnik:
2018, Številka:
5
Journal Article
Recenzirano
Odprti dostop
A
bstract
The product of the electronic width of the
J/ψ
meson and the branching fractions of its decay to hadrons and electrons has been measured using the KEDR detector at the VEPP-4M
e
+
e
−
...collider. The obtained values are
Γ
e
e
J
/
ψ
=
5.550
±
0.056
±
0.089
keV
,
Γ
e
e
J
/
ψ
·
ℬ
hadrons
J
/
ψ
=
4.884
±
0.048
±
0.078
keV
,
Γ
e
e
J
/
ψ
·
ℬ
e
e
J
/
ψ
=
0.3331
±
0.0066
±
0.0040
keV
.
The uncertainties shown are statistical and systematic, respectively. Using the result presented and the world-average value of the electronic branching fraction, one obtains the total width of the
J/ψ
meson:
Γ
=
92.94
±
1.83
keV
.
These results are consistent with the previous experiments.
Study of the radiation hardness of the pure CsI crystals Bedny, I.V.; Bondar, A.E.; Cherepkov, V.V. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
2009, 2009-1-00, Letnik:
598, Številka:
1
Journal Article
Recenzirano
This study was initiated by the Belle detector upgrade plan including the replacement of the CsI(Tl) crystals in the endcaps by the pure CsI. Within this work five samples of pure CsI crystals were ...irradiated by the beam of
0.6
MeV
γ
-quanta. The absorbed dose accumulated in several runs reached 55
krad for two samples and 13
krad for three others. Four of these samples were found to satisfy the super B-factory conditions. The light output reduction for them does not exceed 15% at 13
krad of absorbed dose. One sample had poor radiation resistance.
How does first-person sensory experience contribute to knowledge? Contrary to the suppositions of early empiricist philosophers, people who are born blind know about phenomena that cannot be ...perceived directly, such as color and light. Exactly what is learned and how remains an open question. We compared knowledge of animal appearance across congenitally blind (n = 20) and sighted individuals (two groups, n = 20 and n = 35) using a battery of tasks, including ordering (size and height), sorting (shape, skin texture, and color), odd-one-out (shape), and feature choice (texture). On all tested dimensions apart from color, sighted and blind individuals showed substantial albeit imperfect agreement, suggesting that linguistic communication and visual perception convey partially redundant appearance information. To test the hypothesis that blind individuals learn about appearance primarily by remembering sighted people’s descriptions of what they see (e.g., “elephants are gray”), we measured verbalizability of animal shape, texture, and color in the sighted. Contrary to the learn-from-description hypothesis, blind and sighted groups disagreed most about the appearance dimension that was easiest for sighted people to verbalize: color. Analysis of disagreement patterns across all tasks suggest that blind individuals infer physical features from non-appearance properties of animals such as folk taxonomy and habitat (e.g., bats are textured like mammals but shaped like birds). These findings suggest that in the absence of sensory access, structured appearance knowledge is acquired through inference from ontological kind.
Classic theories emphasize the primacy of first-person sensory experience for learning meanings of words: to know what “see” means, one must be able to use the eyes to perceive. Contrary to this ...idea, blind adults and children acquire normative meanings of “visual” verbs, e.g., interpreting “see” and “look” to mean with the eyes for sighted agents. Here we ask the flip side of this question: how easily do sighted children acquire the meanings of “visual” verbs as they apply to blind agents? We asked sighted 4-, 6- and 9-year-olds to tell us what part of the body a blind or a sighted agent would use to “see”, “look” (and other visual verbs, n = 5), vs. “listen”, “smell” (and other non-visual verbs, n = 10). Even the youngest children consistently reported the correct body parts for sighted agents (eyes for “look”, ears for “listen”). By contrast, there was striking developmental change in applying “visual” verbs to blind agents. Adults, 9- and 6-year-olds, either extended visual verbs to other modalities for blind agents (e.g., “seeing” with hands or a cane) or stated that the blind agent “cannot” “look” or “see”. By contrast, 4-year-olds said that a blind agent would use her eyes to “see”, “look”, etc., even while explicitly acknowledging that the agent's “eyes don't work”. Young children also endorsed “she is looking at the dax” descriptions of photographs where the blind agent had the object in her “line of sight”, irrespective of whether she had physical contact with the object. This pattern held for leg-motion verbs (“walk”, “run”) applied to wheelchair users. The ability to modify verb modality for agents with disabilities undergoes developmental change between 4 and 6. Despite this, we find that 4-year-olds are sensitive to the semantic distinction between active (“look”) and stative (“see”), even when applied to blind agents. These results challenge the primacy of first-person sensory experience and highlight the importance of linguistic input and social interaction in the acquisition of verb meaning.
•By age 4, children have learned the modality linked to many perception verbs.•These verb meanings are initially tightly coupled to their canonical modality.•Verb meanings are initially resistant to extension to atypical agents.•Children show early sensitivity to the active/stative distinction for visual verbs.•Understanding a verb's meaning requires integrating multiple sources of information.
Abstract
What is the neural organization of the mental lexicon? Previous research suggests that partially distinct cortical networks are active during verb and noun processing, but what information ...do these networks represent? We used multivoxel pattern analysis (MVPA) to investigate whether these networks are sensitive to lexicosemantic distinctions among verbs and among nouns and, if so, whether they are more sensitive to distinctions among words in their preferred grammatical class. Participants heard 4 types of verbs (light emission, sound emission, hand-related actions, mouth-related actions) and 4 types of nouns (birds, mammals, manmade places, natural places). As previously shown, the left posterior middle temporal gyrus (LMTG+), and inferior frontal gyrus (LIFG) responded more to verbs, whereas the inferior parietal lobule (LIP), precuneus (LPC), and inferior temporal (LIT) cortex responded more to nouns. MVPA revealed a double-dissociation in lexicosemantic sensitivity: classification was more accurate among verbs than nouns in the LMTG+, and among nouns than verbs in the LIP, LPC, and LIT. However, classification was similar for verbs and nouns in the LIFG, and above chance for the nonpreferred category in all regions. These results suggest that the lexicosemantic information about verbs and nouns is represented in partially nonoverlapping networks.
We report a measurement of the exclusive e+ e- -->Lambda+_(c)Lambda-_(c) cross section as a function of center-of-mass energy near the Lambda+_(c)Lambda-_(c) threshold. A clear peak with a ...significance of 8.2sigma is observed in the Lambda+_(c)Lambda-_(c) invariant mass distribution just above threshold. With an assumption of a resonance origin for the observed peak, a mass and width of M=4634 (+8)_(-7)(stat)(+5)_(-8)(syst) MeV/c(2) and Gamma_(tot)=92 (+40)_(-24)(stat)(+10)_(-21)(syst) MeV are determined. The analysis is based on a study of events with initial-state-radiation photons in a data sample collected with the Belle detector at the Upsilon(4S) resonance and nearby continuum with an integrated luminosity of 695 fb(-1) at the KEKB asymmetric-energy e+ e- collider.
REPLY TO LEWIS ET AL Kim, Judy S.; Elli, Giulia V.; Bedny, Marina
Proceedings of the National Academy of Sciences - PNAS,
09/2019, Letnik:
116, Številka:
39
Journal Article
PDF
