Abstract
Exclusive photoproduction of
$${{\rho ^0}} (770)$$
ρ
0
(
770
)
mesons is studied using the H1 detector at the
ep
collider HERA. A sample of about 900,000 events is used to measure single- ...and double-differential cross sections for the reaction
$$\gamma p \rightarrow \pi ^{+}\pi ^{-}Y$$
γ
p
→
π
+
π
-
Y
. Reactions where the proton stays intact (
$${{{m_Y}} {=}m_p}$$
m
Y
=
m
p
) are statistically separated from those where the proton dissociates to a low-mass hadronic system (
$$m_p{<}{{m_Y}} {<}10~{{\text {GeV}}} $$
m
p
<
m
Y
<
10
GeV
). The double-differential cross sections are measured as a function of the invariant mass
$$m_{\pi \pi }$$
m
π
π
of the decay pions and the squared 4-momentum transfer
t
at the proton vertex. The measurements are presented in various bins of the photon–proton collision energy
$${{W_{\gamma p}}} $$
W
γ
p
. The phase space restrictions are
$$0.5\le m_{\pi \pi } \le 2.2~{{\text {GeV}}} $$
0.5
≤
m
π
π
≤
2.2
GeV
,
$$\vert t\vert \le 1.5~{{\text {GeV}^2}} $$
|
t
|
≤
1.5
GeV
2
, and
$$20 \le W_{\gamma p} \le 80~{{\text {GeV}}} $$
20
≤
W
γ
p
≤
80
GeV
. Cross section measurements are presented for both elastic and proton-dissociative scattering. The observed cross section dependencies are described by analytic functions. Parametrising the
$${m_{\pi \pi }}$$
m
π
π
dependence with resonant and non-resonant contributions added at the amplitude level leads to a measurement of the
$${{\rho ^0}} (770)$$
ρ
0
(
770
)
meson mass and width at
$$m_\rho = 770.8{}^{+2.6}_{-2.7}~({\text {tot.}})~{{\text {MeV}}} $$
m
ρ
=
770.8
-
2.7
+
2.6
(
tot.
)
MeV
and
$$\Gamma _\rho = 151.3 {}^{+2.7}_{-3.6}~({\text {tot.}})~{{\text {MeV}}} $$
Γ
ρ
=
151.3
-
3.6
+
2.7
(
tot.
)
MeV
, respectively. The model is used to extract the
$${{\rho ^0}} (770)$$
ρ
0
(
770
)
contribution to the
$$\pi ^{+}\pi ^{-}$$
π
+
π
-
cross sections and measure it as a function of
t
and
$${W_{\gamma p}}$$
W
γ
p
. In a Regge asymptotic limit in which one Regge trajectory
$$\alpha (t)$$
α
(
t
)
dominates, the intercept
$$\alpha (t{=}0) = 1.0654\ {}^{+0.0098}_{-0.0067}~({\text {tot.}})$$
α
(
t
=
0
)
=
1.0654
-
0.0067
+
0.0098
(
tot.
)
and the slope
$$\alpha ^\prime (t{=}0) = 0.233 {}^{+0.067 }_{-0.074 }~({\text {tot.}}) ~{{\text {GeV}^{-2}}} $$
α
′
(
t
=
0
)
=
0.233
-
0.074
+
0.067
(
tot.
)
GeV
-
2
of the
t
dependence are extracted for the case
$$m_Y{=}m_p$$
m
Y
=
m
p
.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
When the light propagates in media where absorption is not negligible and/or scattering is weak, a contribution to the energy density coming from ballistic photons cannot be neglected. A point source ...effectively spreads out over a scattering volume and its spatial distribution is described by the source function. We consider a boundary value problem of light propagation in half-space for such a source on the basis of the telegraph equation. A solution is found by convolution of Green's function with the source function. The final result shows a significant difference in the behavior of the radiant energy density between the solution obtained for a distributed source and the diffusion approximation. Our results agree well with the Monte Carlo simulations over a broad range of scattering and/or absorption conditions. The obtained results are of practical importance in luminescence optical tomography because an erroneous shape of the energy density function may lead to an incorrect estimate of the light source depth after image reconstruction. The range of applications of the diffusion approximation is also discussed.
First measurements of beam backgrounds at SuperKEKB Lewis, P. M.; Jaegle, I.; Nakayama, H. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
06/2018, Letnik:
914, Številka:
C
Journal Article
Recenzirano
Odprti dostop
The high design luminosity of the SuperKEKB electron-positron collider is expected to result in challenging levels of beam-induced backgrounds in the interaction region. Properly simulating and ...mitigating these backgrounds is critical to the success of the Belle~II experiment. We report on measurements performed with a suite of dedicated beam background detectors, collectively known as BEAST II, during the so-called Phase 1 commissioning run of SuperKEKB in 2016, which involved operation of both the high energy ring (HER) of 7 GeV electrons as well as the low energy ring (LER) of 4 GeV positrons. We describe the BEAST II detector systems, the simulation of beam backgrounds, and the measurements performed. The measurements include standard ones of dose rates versus accelerator conditions, and more novel investigations, such as bunch-by-bunch measurements of injection backgrounds and measurements sensitive to the energy spectrum and angular distribution of fast neutrons. We observe beam-gas, Touschek, beam-dust, and injection backgrounds. We do not observe significant synchrotron radiation, as expected. Measured LER beam-gas backgrounds and Touschek backgrounds in both rings are slightly elevated, on average three times larger than the levels predicted by simulation. HER beam-gas backgrounds are on on average two orders of magnitude larger than predicted. Systematic uncertainties and channel-to-channel variations are large, so that these excesses constitute only 1-2 sigma level effects. Neutron background rates are higher than predicted and should be studied further. We will measure the remaining beam background processes, due to colliding beams, in the imminent commissioning Phase 2. These backgrounds are expected to be the most critical for Belle II, to the point of necessitating replacement of detector components during the Phase 3 (full-luminosity) operation of SuperKEB
Exclusive photoproduction of
ρ
0
(
770
)
mesons is studied using the H1 detector at the
ep
collider HERA. A sample of about 900,000 events is used to measure single- and double-differential cross ...sections for the reaction
γ
p
→
π
+
π
-
Y
. Reactions where the proton stays intact (
m
Y
=
m
p
) are statistically separated from those where the proton dissociates to a low-mass hadronic system (
m
p
<
m
Y
<
10
GeV
). The double-differential cross sections are measured as a function of the invariant mass
m
π
π
of the decay pions and the squared 4-momentum transfer
t
at the proton vertex. The measurements are presented in various bins of the photon–proton collision energy
W
γ
p
. The phase space restrictions are
0.5
≤
m
π
π
≤
2.2
GeV
,
|
t
|
≤
1.5
GeV
2
, and
20
≤
W
γ
p
≤
80
GeV
. Cross section measurements are presented for both elastic and proton-dissociative scattering. The observed cross section dependencies are described by analytic functions. Parametrising the
m
π
π
dependence with resonant and non-resonant contributions added at the amplitude level leads to a measurement of the
ρ
0
(
770
)
meson mass and width at
m
ρ
=
770.8
-
2.7
+
2.6
(
tot.
)
MeV
and
Γ
ρ
=
151.3
-
3.6
+
2.7
(
tot.
)
MeV
, respectively. The model is used to extract the
ρ
0
(
770
)
contribution to the
π
+
π
-
cross sections and measure it as a function of
t
and
W
γ
p
. In a Regge asymptotic limit in which one Regge trajectory
α
(
t
)
dominates, the intercept
α
(
t
=
0
)
=
1.0654
-
0.0067
+
0.0098
(
tot.
)
and the slope
α
′
(
t
=
0
)
=
0.233
-
0.074
+
0.067
(
tot.
)
GeV
-
2
of the
t
dependence are extracted for the case
m
Y
=
m
p
.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
DEPFET pixel detector in the Belle II experiment Abudinen, F.; Ackermann, K.; Albalawi, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
08/2019, Letnik:
936
Journal Article
Recenzirano
The Belle II experiment will run with a reduced beam asymmetry and a factor of 40 higher instantaneous luminosity compared to the Belle experiment. To cope with this and to be able to perform high ...precision vertex measurements for charge conjugation parity violating processes, a pixel detector based on DEPFET technology will be installed in the center of Belle II. Its basic properties and the DAQ chain are presented in this article.
•The Belle II experiment will achieve a 40 times higher luminosity compared to Belle.•To study CP violating processes, Belle II is equipped with a pixel detector.•The pixel detector is based on DEPFET technology with a read out frequency of 30 kHz.•Online data reduction is performed by removing background hits during DAQ.•The goal is a data reduction by a factor of ten for full luminosity.
The aim
of this investigation was to evaluate the expression of LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18) β
2
integrins on blood cells in CBA mice in ontogenesis as well as under the dry extract of ...multifitoadaptogen administration during the first month of postnatal development.
Materials and methods
. The study was carried out on CBA male mice (CBA/LacY). The experimental mice received 0.3 % dry multiphytoadaptogene extract water-solution during the first month of life (preventive administration). Preparation was produced by a desiccation technology of forty medical herbs (including Panax ginseng, Eleutherococcus senticosus, Rhodiola rosea) water-ethanol extracts components. The CD11a and CD11b antigens expressions on peripheral blood cells were analyzed by indirect immunofluorescence reaction at the age of 4, 8, 22 months. Statistical analysis was performed with the program Statistica 6.0.
Results
. The development of genetically predisposed hepatocarcinomas in CBA male-mice was accompanied by a decrease in the expression of СD11a and CD11b antigens on blood cells. Dry multiphytoadaptogene extract administration during the first month of postnatal ontogenesis revealed the CD11a and CD11b antigens up-regulated expression. The effect of the dry multiphytoadaptogene extract is comparable to that for the liquid form of multifitoadaptogen previously identified.
Conclusion
. Up-regulated LFA-1 and Mac-1 β
2
integrins expression on blood cells using dry multiphytoadaptogene extract administration during the first month of postnatal development is essential for enhance the contact interactions of immune effectors and cancer cells.
The study was performed in accordance with ethical principles adopted by the European Convention for the protection of vertebrate animals used for experimental and other scientific purposes.
The purpose
of this investigation was to evaluate the efficacy of correcting the LFA-1 and Mac-1 leukocyte integrins expression on peripheral blood cells as well as IL-6 and IL-10 serum levels using ...liquid form multiphytoadaptogene preventive application for hepatocarcinomas incidence suppression and life-span increase of CBA inbreed mice.
Materials and methods.
The study was carried out on 439 males of inbred CBA mouse strain (subline CBA/LacY). The experimental mice received 10 % liquid form multiphytoadaptogene complex (MPAC) solution in drinking water during the first month of life including the final time period of liver differentiation (preventive administration). MPAC is the standardized herbal formula composed of 40 plant extracts components including adaptogenes Panax ginseng, Eleutherococcus senticosus, Rhodiola rosea, as well as compounds with phenolic structure (flavonoids, triterpene glycosides, etc). Anti-mutagenic, anti-oxidant, immunomodifying activities of MPAC were demonstrated. The CD11a and CD11b antigens expressions on peripheral blood cells were analyzed by indirect immunofluorescence reaction, serum cytokines IL-6 and IL-10 concentrations were determined by enzyme-linked immunosorbent assay as well as the liver tissue morphology were analyzed at the age of 4, 8, 22 months. Tumor incidence and volumes were evaluated at the age of 8 and 22 months. Motor activity and physical status (body weight, coat state) were estimated in the ontogenesis. The average life-span and survival median was analyzed by the Kaplan–Meier method. Statistical analysis was performed with the program STATISTICA 6.0.
Results.
Inhibited expression of LFA-1 and Mac-1 leukocyte integrins on peripheral blood cells as well as elevated IL-6 and IL-10 serum levels, high incidence of liver tumors (100 % of mice-males), their high number and big sizes in the late period of postnatal ontogenesis in CBA high-cancer inbrede mice, also as life-span not reaching two years was demonstrated. At the same time plural tumor-infiltrating limphocytes were not found. Short-term MPAC preventive administration (during the first month of mouse life occupying the final differentiation period of liver tissue genetically predisposal to hepatoms incidence) revealed the long-term heterotypic adhesion molecules leukocyte integrins LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18) up-regulated expression, providing the contact interactions of immune effectors and cancer cells. The events shown is able to enhance the anti-tumor activity of immune reactions including spontaneous hepatocarcinomas lymphocytes infiltration and destruction of tumor tissue. As a result, the hereditary tumors incidence, their number and sizes were reduced as well as life-span and life quality of animals were improved.
Conclusion.
Up-regulated leukocyte integrins expression on peripheral blood cells, reduced IL-6 and IL-10 serum levels accompanied by tumors lymphocyte infiltration and destruction using MPAC preventive administration is essential for tumor incidence down-regulation. The herbal formula with multiple components is capable to controle anti-tumor immune reactions, as well as the life-span and life quality of high-cancer animals. Hence, the regulation of adhesion violations involved in tumor incidence can be cancer preventive.
Abstract
The strong coupling constant
$$\alpha _\mathrm{s}$$
α
s
is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic
ep
scattering (DIS) measured at HERA by ...the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of
$$\alpha _\mathrm{s} (m_\mathrm{Z})$$
α
s
(
m
Z
)
at the
Z
-boson mass
$$m_Z$$
m
Z
are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be
$$\alpha _\mathrm{s} (m_\mathrm{Z}) =0.1157\,(20)_\mathrm{exp}\,(29)_\mathrm{th}$$
α
s
(
m
Z
)
=
0.1157
(
20
)
exp
(
29
)
th
. Complementary,
$$\alpha _\mathrm{s} (m_\mathrm{Z})$$
α
s
(
m
Z
)
is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value
$$\alpha _\mathrm{s} (m_\mathrm{Z}) =0.1142\,(28)_\mathrm{tot}$$
α
s
(
m
Z
)
=
0.1142
(
28
)
tot
obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The strong coupling constant Formula omitted is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration ...using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of Formula omitted at the Z-boson mass Formula omitted are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be Formula omitted. Complementary, Formula omitted is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value Formula omitted obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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