Permanent electric dipole moments (EDMs) of fundamental particles provide powerful probes for physics beyond the Standard Model. We propose to search for the EDM of strange and charm baryons at LHC, ...extending the ongoing experimental program on the neutron, muon, atoms, molecules and light nuclei. The EDM of strange
Λ
baryons, selected from weak decays of charm baryons produced in
p
p
collisions at LHC, can be determined by studying the spin precession in the magnetic field of the detector tracking system. A test of
C
P
T
symmetry can be performed by measuring the magnetic dipole moment of
Λ
and
Λ
¯
baryons. For short-lived
Λ
c
+
and
Ξ
c
+
baryons, to be produced in a fixed-target experiment using the 7
TeV
LHC beam and channeled in a bent crystal, the spin precession is induced by the intense electromagnetic field between crystal atomic planes. The experimental layout based on the LHCb detector and the expected sensitivities in the coming years are discussed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We propose a unique program of measurements of electric and magnetic dipole moments of charm, beauty and strange charged baryons at the LHC, based on the phenomenon of spin precession of channeled ...particles in bent crystals. Studies of crystal channeling and spin precession of positively- and negatively-charged particles are presented, along with feasibility studies and expected sensitivities for the proposed experiment using a layout based on the LHCb detector.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Physics Beyond Colliders initiative is an exploratory study aimed at exploiting the full scientific potential of the CERN's accelerator complex and scientific infrastructures through projects ...complementary to the LHC and other possible future colliders. These projects will target fundamental physics questions in modern particle physics. This document presents the status of the proposals presented in the framework of the Beyond Standard Model physics working group, and explore their physics reach and the impact that CERN could have in the next 10-20 years on the international landscape.
One of the most important symmetries in nature is time reversal, namely, that the laws of physics remain dynamically invariant from moving forward to backward in time. Nevertheless, this symmetry can ...be broken in certain physical processes as observed in neutral B mesons by the BABAR Collaboration. Symmetry transformations have been proven a bedrock tool for understanding the nature of particle interactions, formulating, and testing fundamental theories. Based on the up to now unbroken CPT symmetry, the violation of the CP symmetry between matter and antimatter by weak interactions, discovered in the decay of kaons in 1964 and observed more recently in 2001 in mesons, strongly suggests that the behavior of these particles under weak interactions must also be asymmetric under time reversal T. The method allows a clear-cut separation of different transitions between flavor and eigenstates in the decay of neutral mesons. The results, presented in 2012, prove beyond any doubt the violation of time-reversal invariance in the time evolution between these two states of the neutral B meson.
A novel method for the direct measurement of the elusive magnetic and electric dipole moments of the τ lepton is presented. The experimental approach relies on the production of τ^{+} leptons from ...D_{s}^{+}→τ^{+}ν_{τ} decays, originating in fixed-target collisions at the LHC. A sample of polarized τ^{+} leptons is kinematically selected and subsequently channeled in a bent crystal. The magnetic and electric dipole moments of the τ^{+} lepton are measured by determining the rotation of the spin-polarization vector induced by the intense electromagnetic field between crystal atomic planes. The experimental technique is discussed along with the expected sensitivities.
In this Erratum, an improved simulation of the channeling efficiency of protons and antiprotons as a function of the particle momentum is shown in for different configurations
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Electromagnetic dipole moments of short-lived particles are sensitive to physics within and beyond the Standard Model of particle physics but have not been accessible experimentally to date. To ...perform such measurements it has been proposed to exploit the spin precession of channeled particles in bent crystals at the LHC. Progress that enables the first measurement of charm baryon dipole moments is reported. In particular, the design and characterization on beam of silicon and germanium bent crystal prototypes, the optimization of the experimental setup, and advanced analysis techniques are discussed. Sensitivity studies show that first measurements of Λc+ and Ξc+ baryon dipole moments can be performed in two years of data taking with an experimental setup positioned upstream of the LHCb detector.
The Childbirth Experience Questionnaire (CEQ) was originally designed to study women's perceptions of labour and birth. The main objective of our study was to adapt the CEQ to the Spanish context and ...determine its psychometric properties. This would provide an opportunity to evaluate women's experiences in order to improve evidence in the Spanish context as recommended by national guidelines.
The CEQ was translated into Spanish using a standard forward and back translation method (CEQ-E). A convenience sample of 364 women was recruited from 3 Spanish hospitals; all participants were able to read and write in Spanish. Mothers with high risk pregnancies or preterm deliveries were excluded from the study. A self-administered questionnaire on sociodemographic variables was completed by participants before discharge. Data on childbirth variables were obtained from maternity records. Between 1 and 3 months postpartum a postal CEQ-E questionnaire was sent. The CEQ-E structure was examined by a confirmatory factor analysis of polychoric correlations using a diagonally weighted least squares estimator. Reliability was assessed using Cronbach's alpha. Construct validity was conducted by testing differences in CEQ-E scores between known-groups (to differ on key variables).
226 (62.1%) of the recruited participants completed the postal questionnaire. The CEQ-E factor structure was similar to the original one. The Spanish version showed fit statistics in line with standard recommendations: CFI = 0.97; NNFI = 0.97; RMSEA = 0.066; SRMS = 0.077. The internal consistency reliability of the CEQ-E was good for the overall scale (0.88) and for all subscales (0.80, 0.90, 0.76, 0.68 for "own capacity", "professional support", "perceived safety" and "participation", respectively) and similar to the original version. Women with a labour duration ≤ 12 h, women with a labour not induced, women with a normal birth and multiparous women showed higher overall CEQ-E scores and "perceived safety" subscale scores. Women with a labour duration ≤ 12 h and those with previous experience of labour obtained higher scores for the "own capacity" and "participation" subscales.
The results of this study indicate that the CEQ-E can be considered a valid and reliable measure of women's perceptions of labour and birth in Spain.
Carbapenemase-producing Enterobacterales constitute a serious public health threat; however, information on the oxacilinasa (OXA-48)-type is limited. The objective of the study was to evaluate the ...risk factors associated with 14-day mortality for patients with bacteremia due to OXA-48 carbapenemase-producing Klebsiella pneumoniae.We conducted a retrospective, single-center observational study of adult patients with K. pneumoniae bacteremia, classifying the strains as carbapenem-susceptible K. pneumoniae (CSKp) and carbapenem-resistant K. pneumoniae (CRKp). All of the CRKp strains were the OXA-48-type.The study included 202 cases of bacteremia: 114 due to CSKp and 88 due to CRKp. The clinical cure rate was higher for the patients with CSKp (85% vs 69% for CSKp and CRKp, respectively; P = .010), while the 14-day mortality rate was lower (13% vs 30%, P = .005). An INCREMENT-CPE score ≥7 (HR 3.05, 95% CI 1.50-6.25, P = .002) was the only independent factor associated with 14-day mortality for the patients with Klebsiella spp. bacteremia. Other factors related to 14-day mortality were a rapidly fatal prognosis (McCabe) (HR 7.1, 95% CI 2.75-18.37, P < .001), dementia (HR 5.9, 95% CI 2.0-7.43, P = .001), and a high-risk source of infection (HR 2.7, 95% CI 1.06-6.82, P = .038).The most important factors associated with 14-day mortality for the patients with K. pneumoniae bacteremia was an INCREMENT-CPE score ≥7, dementia, a McCabe score indicating a rapidly fatal prognosis and a high-risk source of infection. We found no relationship between a poorer outcome and CRKp isolation or inadequate antibiotic therapy.
Therapeutic options for bacteremia caused by carbapenem-resistant Enterobacterales (CRE) OXA-48-type are limited. The objective of this study was to analyze clinical success of CAZ-AVI compared with ...best available therapy (BAT) in patients with
Klebsiella pneumoniae
carbapenemase-producing OXA-48-type bacteremia (CRKp-OXA-48). We conducted a retrospective, single-center observational study in adult patients with CRKp-OXA-48 between December 2015 and May 2019. We collected the patients’ clinical and epidemiological characteristics, antibiotic treatment (CAZ-AVI vs. BAT), and evolution. Factors associated with clinical success were analyzed using binary logistic regression. The study included 76 patients with CRKp-OXA-48-type bacteremia 33 received CAZ-AVI and 43 BAT. CAZ-AVI was mainly used in monotherapy (91%). Clinical success was more common in patients < 70-year-old (OR 4.79, 95% CI 1.435–16.002,
p
= 0.011) and CAZ-AVI treatment (OR 6.69, 95% CI 1.68–26.604,
p
= 0.007). Kaplan–Meier survival curve of 14-day mortality showed a lower mortality in patients who received CAZ-AVI (log rank 0.013). However, CAZ-AVI did not achieve statistical difference in IPTW for 14- and 30-day mortality (aOR 0.1, 95% CI 0.02–1.22,
p
= 0.076 and aOR 1.7, 95% CI 0.48–5.98,
p
= 0.413, respectively). CAZ-AVI treatment might be associated with a greater clinical success in CRKp-OXA-48 bacteremia.
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