ESHRE PGT Consortium data collection XXI: PGT analyses in 2018

STUDY QUESTION

What are the trends and developments in preimplantation genetic testing (PGT) in 2018 as compared to previous years?

SUMMARY ANSWER

The main trends observed in this 21st dataset on PGT are that the implementation of trophectoderm biopsy with comprehensive whole-genome testing is most often applied for PGT-A and concurrent PGT-M/SR/A, while for PGT-M and PGT-SR, single-cell testing with PCR and FISH still prevail.

WHAT IS KNOWN ALREADY

Since it was established in 1997, the ESHRE PGT Consortium has been collecting and analysing data from mainly European PGT centres. To date, 20 datasets and an overview of the first 10 years of data collections have been published.

STUDY DESIGN SIZE DURATION

The data for PGT analyses performed between 1 January 2018 and 31 December 2018 with a 2-year follow-up after analysis were provided by participating centres on a voluntary basis. Data were collected using an online platform, which is based on genetic analysis and has been in use since 2016.

PARTICIPANTS/MATERIALS SETTING METHODS

Data on biopsy method, diagnostic technology, and clinical outcome were submitted by 44 centres. Records with analyses for more than one PGT for monogenic disorders (PGT-M) and/or PGT for chromosomal structural rearrangements (PGT-SR), or with inconsistent data regarding the PGT modality, were excluded. All transfers performed within 2 years after the analysis were included, enabling the calculation of cumulative pregnancy rates. Data analysis, calculations, and preparation of figures and tables were carried out by expert co-authors.

MAIN RESULTS AND THE ROLE OF CHANCE

The current data collection from 2018 covers a total of 1388 analyses for PGT-M, 462 analyses for PGT-SR, 3003 analyses for PGT for aneuploidies (PGT-A), and 338 analyses for concurrent PGT-M/SR with PGT-A.The application of blastocyst biopsy is gradually rising for PGT-M (from 19% in 2016-2017 to 33% in 2018), is status quo for PGT-SR (from 30% in 2016-2017 to 33% in 2018) and has become the most used biopsy stage for PGT-A (from 87% in 2016-2017 to 98% in 2018) and for concurrent PGT-M/SR with PGT-A (96%). The use of comprehensive, whole-genome amplification (WGA)-based diagnostic technology showed a small decrease for PGT-M (from 15% in 2016-2017 to 12% in 2018) and for PGT-SR (from 50% in 2016-2017 to 44% in 2018). Comprehensive testing was, however, the main technology for PGT-A (from 93% in 2016-2017 to 98% in 2018). WGA-based testing was also widely used for concurrent PGT-M/SR with PGT-A, as a standalone technique (74%) or in combination with PCR or FISH (24%). Trophectoderm biopsy and comprehensive testing strategies are linked with higher diagnostic efficiencies and improved clinical outcomes per embryo transfer.

LIMITATIONS REASONS FOR CAUTION

The findings apply to the data submitted by 44 participating centres and do not represent worldwide trends in PGT. Details on the health of babies born were not provided in this manuscript.

WIDER IMPLICATIONS OF THE FINDINGS

The Consortium datasets provide a valuable resource for following trends in PGT practice.

STUDY FUNDING/COMPETING INTERESTS

The study has no external funding, and all costs are covered by ESHRE. There are no competing interests declared.

TRIAL REGISTRATION NUMBER

N/A.

Polarization Control in Integrated Graphene-Silicon Quantum Photonics Waveguides

We numerically investigated the use of graphene nanoribbons placed on top of silicon-on-insulator (SOI) strip waveguides for light polarization control in silicon photonic-integrated waveguides. We found that two factors mainly affected the polarization control: the graphene chemical potential and the geometrical parameters of the waveguide, such as the waveguide and nanoribbon widths and distance. We show that the graphene chemical potential influences both TE and TM polarizations almost in the same way, while the waveguide width tapering enables both TE-pass and TM-pass polarizing functionalities. Overall, by increasing the oxide spacer thickness between the silicon waveguide and the top graphene layer, the device insertion losses can be reduced, while preserving a high polarization extinction ratio.

P-563 The effect of embryo culture time on concordance rates between invasive and non-invasive preimplantation genetic testing for aneuploidies (niPGT-A) in spent culture media (SCM) analysis

Study question

To evaluate different embryo culture times (day5 versus day6) to understand the ideal time-frame for the performance of concordance analysis between invasive and non-invasive PGT-A(niPGT-A)

Summary answer

Different levels of ploidy concordance rates were observed between day5 and day6 groups: 72,6% versus 84,8%, respectively

What is known already

The recent data supports that a non-invasive approach for evaluating embryo ploidy status may be an alternative to standard invasive methods. Embryo cell-free DNA(cfDNA) released into culture media during in-vitro embryo development represents the potential source for this analysis. The release of cfDNA from embryos is expected to be directly proportional to embryo culture time and late-stage released cfDNA may be more representative of the embryo. Therefore, it is important to estimate the most effective time frame of the culture that will provide the most conclusive data from spent-culture-media(SCM) without adversely affecting the development of the embryo

Study design, size, duration

A total of 334 SCM from blastocyst stage embryos have been included in this study. The SCM samples were divided in 2 subgroups according to the embryo culture time as day5 (n = 154) and day6 (n = 180). The cfDNA of SCM samples were amplified by whole genome amplification(WGA) and analyzed by next generation sequencing(NGS) in parallel to day5 or day6 trophectodermal(TE) biopsied samples of their corresponding embryos. Ploidy status and concordance were compared between two groups

Participants/materials, setting, methods

Day3 embryos were washed and transferred in 20µl fresh culture media until the biopsy. SCM samples were collected in PCR tubes and stored at -20 °C while embryos were biopsied for standard PGT-A analysis. Both SCM and corresponding TE biopsy samples were amplified by Sureplex(Vitrolife). Then TE and SCM samples were analyzed by next-generation sequencing(NGS) using MiSeq® System (Illumina). Data analysis has been done by Bluefuse Multi Software 4.5(Illumina) for all SCM and TE samples

Main results and the role of chance

A successful DNA amplification rate (>30ng/µl) was obtained in both day5 and day6 groups with 95,5% (147/154) and 99,4% (179/180) respectively. The DNA concentration after WGA was ranging between 30.1-122.5ng/µl and 38.5-123.2ng/µl in day5 and day6 groups respectively. Not conclusive (NC) results including a noisy NGS profile and chaotic chromosome aneuploidies (>5 chromosomes) were excluded in both groups. Therefore, 64,6% (95/147) of SCM samples in day5 group and 81,0% (145/179) of SCM samples in day6 group were conclusive for NGS analysis. The ploidy concordance rate between SCM and TE samples (euploid vs euploid, aneuploid vs aneuploid) was 72,6% (69/95) in day5 and 84,8% (123/145) in day6 group. In day5 group, the false-negative rate was 10.5% (10/95), and false-positive rate was 16.8% (16/95) while in day6 group the false-negative rate was 6,8% (10/145), and false-positive rate was 8,2% (12/145). Sensitivity and specificity were calculated as 83,6% and 52,9% in day5 group, and 90,9% and 65,7 in day6 group respectively

Limitations, reasons for caution

We have high number of samples in our study, but larger prospective studies may change the significance of ploidy concordance. One of the important issues in SCM analysis is the maternal DNA contamination risk which cannot be revealed always. Therefore the use of molecular markers would increase the reliability

Wider implications of the findings

A non-invasive approach for aneuploidy screening may be an alternative to standard PGT-A procedure with invasive embryo biopsy but the evaluation of ideal culture time is crucial for the performance of niPGT-A method. Our study demonstrates that the late collection time of SCM provides significantly better ploidy concordance rates

Trial registration number

Not applicable

O-041 Data from the ESHRE PGT consortium – year 2020

Study question

Which are the trends shown in data collection XXII of the European Society of Human Reproduction and Embryology (ESHRE) PGT Consortium compared with previous years?

Summary answer

Data collection XXII, year 2020, represents valuable data on PGT activity in (mainly) Europe and reports on the main trends observed, being the further expansion of comprehensive testing technology in PGT-SR and PGT-A.

What is known already

The ESHRE PGT Consortium was set up in 1997 and from that time has been collecting data on PGT and PGT-A. The PGT database comprises the world’s largest collection of PGT / PGT-A data providing a valuable resource for data mining and for following trends in PGT practice. So far, up to the year 2015, data collections were carried out in a retrospective data way, from 2016 onwards a prospective cycle-by-cycle data collection was in place.

Study design, size, duration

As the nature of PGT/ PGT-A treatments has changed significantly over the last years and IVF cycle management and genetic analysis techniques are getting more complex, ESHRE uses an online data collection system in which data are collected prospectively from oocyte retrieval to analysis, embryo transfer and pregnancy / live birth. Data are collected cycle by cycle on a voluntary basis.

Participants/materials, settings, method

For the 2020 data, individual centres (37) from 20 countries directly entered the data into the PGT database through software developed by ESHRE. Data were analysed at ESHRE headquarters and include all aspects of PGT/PGT-A cycles.

Main results and the role of chance

The Consortium has analysed the PGT analyses (n = 2809) performed in 2020. The indications for PGT included inherited chromosomal abnormalities (n = 331 analyses), monogenic disorders (n = 987 analyses), aneuploidy testing for infertility (n = 1417 analyses) or combinations of the above (n = 74 analyses). In addition, 704 clinical pregnancies and 335 deliveries have been analysed in detail. The methods used for biopsy were polar body (2%), cleavage stage biopsy (20%) and blastocyst biopsy (78%), showing a further increase of blastocyst biopsy compared to 2019. The methodology used for diagnosis is what is evolving most over the last years, with data set XXII (2020) showing around 4% of FISH, 28% of PCR and 68% of WGA. Within WGA 95% of the analysis were done using NGS, in 4% of the cases SNP arrays were used and in 1% array-CGH was used. The overall clinical pregnancy rate is about 25% per analysis. The baby data show that it is difficult for most centres to have a detailed follow-up.

Limitations, reasons for caution

The findings apply to the 37 participating centres and may not represent worldwide trends in PGT. Data were collected prospectively, but details of the follow-up on PGT pregnancies and babies born were limited.

Wider implications of the findings

The ESHRE PGD Consortium continues its activities as an important forum for PGT practitioners to share data and exchange experiences. The information extracted from the data collections helps to monitor quality issues in PGT and survey the introduction and effectiveness of new PGT technologies and methods.

Trial registration number

Mu2e DAQ and slow control systems

The Mu2e experiment at the Fermilab Muon Campus will search for the coherent neutrinoless conversion of a muon into an electron in the field of an aluminum nucleus with a sensitivity improvement by a factor of 10,000 over existing limits. The Mu2e Trigger and Data Acquisition System (TDAQ) uses otsdaq as the online Data Acquisition System (DAQ) solution. Developed at Fermilab, otsdaq integrates both the artdaq DAQ and the art analysis frameworks for event transfer, filtering, and processing. otsdaq is an online DAQ software suite with a focus on flexibility and scalability and provides a multiuser, web-based, interface accessible through a web browser. The data stream from the detector subsystems is read by a software filter algorithm that selects events which are combined with the data flux coming from a Cosmic Ray Veto System. The Detector Control System (DCS) has been developed using the Experimental Physics and Industrial Control System (EPICS) open source platform for monitoring, controlling, alarming, and archiving. The DCS System has been integrated into otsdaq. A prototype of the TDAQ and the DCS systems has been built at Fermilab’s Feynman Computing Center. In this paper, we report on the progress of the integration of this prototype in the online otsdaq software.

Search for Lepton Number and Flavor Violation in K^{+} and π^{0} Decays

Searches for the lepton number violating K^{+}→π^{-}μ^{+}e^{+} decay and the lepton flavor violating K^{+}→π^{+}μ^{-}e^{+} and π^{0}→μ^{-}e^{+} decays are reported using data collected by the NA62 experiment at CERN in 2017-2018. No evidence for these decays is found and upper limits of the branching ratios are obtained at 90% confidence level: B(K^{+}→π^{-}μ^{+}e^{+})<4.2×10^{-11}, B(K^{+}→π^{+}μ^{-}e^{+})<6.6×10^{-11} and B(π^{0}→μ^{-}e^{+})<3.2×10^{-10}. These results improve by 1 order of magnitude over previous results for these decay modes.

O-009 Data from the ESHRE PGT consortium – year 2019

Study question

Which are the trends shown in data collection XXI of the European Society of Human Reproduction and Embryology (ESHRE) PGT Consortium compared with previous years?

Summary answer

Data collection XXI, year 2019, represents valuable data on PGT activity in (mainly) Europe and reports on the main trends observed, being the further expansion of comprehensive testing technology in PGT-SR and PGT-A.

What is known already

The ESHRE PGT Consortium was set up in 1997 and from that time has been collecting data on PGT and PGT-A. The PGT database comprises the world’s largest collection of PGT / PGT-A data providing a valuable resource for data mining and for following trends in PGT practice. So far, up to the year 2015, data collections were carried out in a retrospective data way, from 2016 onwards a prospective data collection was in place.

Study design, size, duration

As the nature of PGT/ PGT-A treatments has changed significantly over the last years and IVF cycle management and genetic analysis techniques are getting more complex, ESHRE uses an online data collection system in which data are collected prospectively from oocyte retrieval to analysis, embryo transfer and pregnancy / live birth. Data are collected cycle by cycle on a voluntary basis.

Participants/materials, settings, method

For the 2019 data, individual centres (31) from 19 countries directly entered the data into the PGT database through software developed by ESHRE. Data were analysed at ESHRE headquarters and include all aspects of PGT/PGT-A cycles.

Main results and the role of chance

The Consortium has analysed the PGT analyses (n = 2735) performed in 2019. The indications for PGT included inherited chromosomal abnormalities (n = 253 analyses), monogenic disorders (n = 1105 analyses), aneuploidy testing for infertility (n = 1111 analyses) or combinations of the above (n = 266 analyses). In addition, 662 clinical pregnancies and 216 deliveries have been analysed in detail. The methods used for biopsy were polar body (2%), cleavage stage biopsy (35%) and blastocyst biopsy (61%; comparable with data from 2018). The methodology used for diagnosis is what is evolving most over the last years, with data set XXI (2019) showing around 7% of FISH, 37% of PCR and 55% of WGA. Within WGA 90.6% of the analysis were done using NGS, in 4.4% cases SNP arrays were used and in 2.4% array-CGH was used. The overall clinical pregnancy rate is about 24% per analysis. The baby data show that it is difficult for most centres to have a detailed follow-up.

Limitations, reasons for caution

The findings apply to the 31 participating centres and may not represent worldwide trends in PGT. Data were collected prospectively, but details of the follow-up on PGT pregnancies and babies born were limited.

Wider implications of the findings

The ESHRE PGD Consortium continues its activities as an important forum for PGT practitioners to share data and exchange experiences. The information extracted from the data collections helps to monitor quality issues in PGT and survey the introduction and effectiveness of new PGT technologies and methods.

O-201 Prenatal and postnatal outcome of mosaic embryo transfers: multicentric study of one thousand mosaic embryos diagnosed by preimplantation genetic testing with trophectoderm biopsy

Study question

To explore the effect of chromosomal mosaicism detected in preimplantation genetic testing (PGT-A) on prenatal and postnatal outcome of mosaic embryo pregnancies

Summary answer

No significant difference between euploid and mosaic embryos was observed in terms of weeks of gestation, average weight, and developmental defect of the babies born

What is known already

Mosaic embryos have the potential to implant and develop into healthy babies. Transfer of these embryos is now offered as an option for women who undergo IVF resulting in no euploid embryos. While, prenatal diagnosis has shown the depletion of chromosomal mosaicism in mosaic embryos, several concerns remain. For instance, the direct effects of different kind of mosaicism on prenatal/postnatal outcome and the possibility that intra-biopsy mosaicism in the TE is a poor predictor of the ploidy status of the ICM. Thus, there is certainly a need for comprehensive analyses of obstetrical and neonatal outcome data of transferred mosaic embryos.

Study design, size, duration

Compiled analysis from multicenter data on transfers of mosaic embryos (n = 1,000) and their outcome, with comparison to a euploid control group (n = 5,561). To explore the effect of embryonic mosaicism on newborns, we matched mosaic embryos resulting in a birth with a euploid embryo by a series of parameters (maternal age, embryo morphology, and indication for PGT-A). Prenatal tests and birth characteristics of &gt; 200 neonates from mosaic embryo transfers were compared to &gt; 200 euploid embryos.

Participants/materials, setting, methods

PGT-A was performed on blastocyst-stage embryos with 24-Chromosome whole genome amplification (WGA)-based Next Generation Sequencing (NGS). In accordance with established guidelines, embryos were categorized as mosaic when PGT-A results indicated 20-80% aneuploid content. Prenatal testing where performed in 30% of pregnancies with amniocentesis, 4% did an extra analysis for potential UPD for the suspected mosaic chromosome, and an additional 16% performed chorionic villus sampling (CVS) and 9.5% performed noninvasive prenatal testing (NIPT).

Main results and the role of chance

Of the 465 mosaic embryos that implanted, about 20% miscarried, and out of those, 75% were early spontaneous abortions. Of the pregnancies, 3 out of 368 were stillborn (2 out of them were twins that were extremely premature at 23 weeks, and the other died during pregnancy from a heart defect). The remaining 99% of those have been born or are late ongoing pregnancies at the time of analysis. Prenatal tests were performed in &gt; 200 pregnancies and the vast majority tested normal. All 5 abnormal cases were amniocentesis tests showing microdeletions or insertions of sizes smaller than the resolution used during PGT-A, so they were unrelated to the mosaicism detected with PGT-A. In fact, in none of the cases did the prenatal test reflect the mosaicism detected at the embryonic stage. Matching each of the 162 mosaic embryos resulting in a birth with a euploid embryo, we found that the length of gestation was similar on average, and so was the average weight of the babies at birth. We also gathered information on the routine physical examination performed on babies at birth, and of those 162 babies from mosaic embryo transfers, none had obvious developmental defects or gross abnormalities.

Limitations, reasons for caution

Even though newborns resulting from mosaic embryo transfers in this study invariably appeared healthy by routine examination, concerns for long-term health cannot yet be entirely dispelled. The question must therefore be carefully considered by each clinic and patient situation.

Wider implications of the findings

Prenatal testing of &gt; 200 pregnancies from mosaic embryo transfers showed no incidence of mosaicism that matched the PGT-A findings, indicating the involvement of self-corrective mechanisms. Pregnancy and obstetric data indicates that mosaic embryos prevailing through gestation and birth have similar chromosomal and physiological health compared to euploid embryos.

Trial registration number

none

P–582 High level of concordance between invasive and non-invasive preimplantation genetic testing for aneuploidies (niPGT-A) at day5 and day6–7

Study question

To explore ploidy concordance between invasive and non-invasive PGTA (niPGT-A) at different embryo culture time.

Summary answer

High level (&gt;84%) of concordance rate for ploidy and sex, sensitivity (&gt;88%), and specificity (76%) were obtained for both day6/7 samples and day5 samples.

What is known already

The analysis of embryo cell free DNA (cfDNA) that are released into culture media during in vitro embryo development has the potential to evaluate embryo ploidy status. However, obtaining sufficient quality and quantity of cfDNA is essential to achieve interpretable results for niPGT-A. More culture time is expected to be directly proportional to the release of more cfDNA. But embryo culture time is limited due to in-vitro embryo survival potential. Therefore, it is important to estimate the duration of the culture that will provide the maximum cfDNA that can be obtained without adversely affecting the development of the embryo.

Study design, size, duration

A total of 105 spent culture media (SCM) from day5-day7 blastocyst stage embryos have been included in this cohort study. The cfDNA of SCM samples were amplified and analyzed for niPGT-A by NGS analysis. The SCM samples were divided into 2 subgroups according the embryo culture hours (Day5 and Day6/7 group). The DNA concentration, informativity and euploidy results have then been compared with their corresponding embryos after trophectoderm biopsy (TE) and PGT-A analysis by NGS

Participants/materials, setting, methods

Embryos cultured until Day3 washed and cultured again in 20µl fresh culture media until embryo biopsy on Day5, 6, or 7. After biopsy SCM samples were immediately collected in PCR tubes and conserved at –20 °C until whole genome amplification by MALBAC® (Yicon Genomics). The TE and SCM samples were analyzed by next-generation sequencing (NGS) using Illumina MiSeq® System. NGS data analysis has been done by Bluefuse Multi Software 4.5 (Illumina) for SCM and TE samples

Main results and the role of chance

Only the SCM samples which have an embryo with a conclusive result were included in this cohort (n = 105). Overall 97.1% (102/105) of SCM samples gave a successful DNA amplification with a concentration ranging 32.4–128.5ng/µl. Non-informative (NI) results including a chaotic profile (&gt;5 chromosome aneuploidies) were observed in 17 samples, so 83.3%(85/102) of SCM samples were informative for NGS data analysis. Ploidy concordance rate with the corresponding TE biopsies (euploid vs euploid, aneuploid vs aneuploid) was 84.7% (72/85). Sensitivity and specificity were 92,8% and 76,7%, respectively with no significant difference for all parameters for day 6/7 samples compared with day 5 samples. The false-negative rate was 3.5% (3/85), and false-positive rate was 11.7% (10/85).

Limitations, reasons for caution

The sample size is relatively small. Larger prospective studies are needed. As this is a single-center study, the impact of the variations in embryo culture conditions can be underestimated. Maternal DNA contamination risk cannot be revealed in SCM, therefore the use of molecular markers would increase the reliability.

Wider implications of the findings: Non-invasive analysis of embryo cfDNA analyzed in spent culture media demonstrates high concordance with TE biopsy results in both early and late culture time. A non-invasive approach for aneuploidy screening offers important advantages such as avoiding invasive embryo biopsy and decreased cost, potentially increasing accessibility for a wider patient population.

Trial registration number

Not applicable

NA62 and NA48/2 results on search for Heavy Neutral Leptons

In this paper we present new results on upper limits for the search of Heavy Neutral Leptons (HNL) with data collected by NA48/2 (2003-2004), NA62-RK (2007) and NA62 (2015) CERN experiments. The data collected with different trigger configuration allow to search for both long and short living heavy neutrinos in the mass range below the kaon mass. In addition the status of the search for K+ → π+vv with the NA62 detector will be briefly presented.

Precision Measurement of the Helium Flux in Primary Cosmic Rays of Rigidities 1.9 GV to 3 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the precise rigidity dependence of the helium flux is important in understanding the origin, acceleration, and propagation of cosmic rays. A precise measurement of the helium flux in primary cosmic rays with rigidity (momentum/charge) from 1.9 GV to 3 TV based on 50 million events is presented and compared to the proton flux. The detailed variation with rigidity of the helium flux spectral index is presented for the first time. The spectral index progressively hardens at rigidities larger than 100 GV. The rigidity dependence of the helium flux spectral index is similar to that of the proton spectral index though the magnitudes are different. Remarkably, the spectral index of the proton to helium flux ratio increases with rigidity up to 45 GV and then becomes constant; the flux ratio above 45 GV is well described by a single power law.

Validation of a semiconductor next-generation sequencing-based protocol for preimplantation genetic diagnosis of reciprocal translocations

OBJECTIVE

We aim to validate a semiconductor next-generation sequencing (NGS)-based method to detect unbalanced chromosome translocation in preimplantation embryos.

METHODS

The study consisted of a blinded retrospective evaluation with NGS of 145 whole-genome amplification products obtained from biopsy of cleavage-stage embryos or blastocysts, derived from 33 couples carrying different balanced translocations. Consistency of NGS-based copy number assignments was evaluated and compared with the results obtained by array-comparative genomic hybridization.

RESULTS

Reliably identified with the NGS-based protocol were 162 segmental imbalances derived from 33 different chromosomal translocations, with the smallest detectable chromosomal segment being 5 Mb in size. Of the 145 embryos analysed, 20 (13.8%) were balanced, 43 (29.6%) were unbalanced, 53 (36.5%) were unbalanced and aneuploid, and 29 (20%) were balanced but aneuploid. NGS sensitivity for unbalanced/aneuploid chromosomal call (consistency of chromosome copy number assignment) was 99.75% (402/403), with a specificity of 100% (3077/3077). NGS specificity and sensitivity for unbalanced/aneuploid embryo call were 100%.

CONCLUSIONS

Next-generation sequencing can detect chromosome imbalances in embryos with the added benefit of simultaneous comprehensive aneuploidy screening. Given the high level of consistency with array-comparative genomic hybridization, NGS has been demonstrated to be a robust high-throughput technique ready for clinical application in preimplantation genetic diagnosis for chromosomal translocations, with potential advantages of automation, increased throughput and reduced cost.

Precision Measurement of the Proton Flux in Primary Cosmic Rays from Rigidity 1 GV to 1.8 TV with the Alpha Magnetic Spectrometer on the International Space Station

A precise measurement of the proton flux in primary cosmic rays with rigidity (momentum/charge) from 1 GV to 1.8 TV is presented based on 300 million events. Knowledge of the rigidity dependence of the proton flux is important in understanding the origin, acceleration, and propagation of cosmic rays. We present the detailed variation with rigidity of the flux spectral index for the first time. The spectral index progressively hardens at high rigidities.

Precision Measurement of the (e^{+}+e^{-}) Flux in Primary Cosmic Rays from 0.5 GeV to 1 TeV with the Alpha Magnetic Spectrometer on the International Space Station

We present a measurement of the cosmic ray (e^{+}+e^{-}) flux in the range 0.5 GeV to 1 TeV based on the analysis of 10.6 million (e^{+}+e^{-}) events collected by AMS. The statistics and the resolution of AMS provide a precision measurement of the flux. The flux is smooth and reveals new and distinct information. Above 30.2 GeV, the flux can be described by a single power law with a spectral index γ=-3.170±0.008(stat+syst)±0.008(energy scale).

Electron and positron fluxes in primary cosmic rays measured with the alpha magnetic spectrometer on the international space station

Precision measurements by the Alpha Magnetic Spectrometer on the International Space Station of the primary cosmic-ray electron flux in the range 0.5 to 700 GeV and the positron flux in the range 0.5 to 500 GeV are presented. The electron flux and the positron flux each require a description beyond a single power-law spectrum. Both the electron flux and the positron flux change their behavior at ∼30  GeV but the fluxes are significantly different in their magnitude and energy dependence. Between 20 and 200 GeV the positron spectral index is significantly harder than the electron spectral index. The determination of the differing behavior of the spectral indices versus energy is a new observation and provides important information on the origins of cosmic-ray electrons and positrons.

High statistics measurement of the positron fraction in primary cosmic rays of 0.5-500 GeV with the alpha magnetic spectrometer on the international space station

A precision measurement by AMS of the positron fraction in primary cosmic rays in the energy range from 0.5 to 500 GeV based on 10.9 million positron and electron events is presented. This measurement extends the energy range of our previous observation and increases its precision. The new results show, for the first time, that above ∼200  GeV the positron fraction no longer exhibits an increase with energy.

Observation of the resonant character of the Z(4430)(-) state

Resonant structures in B^{0}→ψ^{'}π^{-}K^{+} decays are analyzed by performing a four-dimensional fit of the decay amplitude, using pp collision data corresponding to 3  fb^{-1} collected with the LHCb detector. The data cannot be described with K^{+}π^{-} resonances alone, which is confirmed with a model-independent approach. A highly significant Z(4430)^{-}→ψ^{'}π^{-} component is required, thus confirming the existence of this state. The observed evolution of the Z(4430)^{-} amplitude with the ψ^{'}π^{-} mass establishes the resonant nature of this particle. The mass and width measurements are substantially improved. The spin parity is determined unambiguously to be 1^{+}.

Measurement of charged particle multiplicities and densities in [Formula: see text] collisions at [Formula: see text]TeV in the forward region

Charged particle multiplicities are studied in proton-proton collisions in the forward region at a centre-of-mass energy of [Formula: see text]TeV with data collected by the LHCb detector. The forward spectrometer allows access to a kinematic range of [Formula: see text] in pseudorapidity, momenta greater than [Formula: see text] and transverse momenta greater than [Formula: see text]. The measurements are performed using events with at least one charged particle in the kinematic acceptance. The results are presented as functions of pseudorapidity and transverse momentum and are compared to predictions from several Monte Carlo event generators.

Measurement of [Formula: see text] polarisation in [Formula: see text] collisions at [Formula: see text] = 7 TeV

The polarisation of prompt [Formula: see text] mesons is measured by performing an angular analysis of [Formula: see text] decays using proton-proton collision data, corresponding to an integrated luminosity of 1.0[Formula: see text], collected by the LHCb detector at a centre-of-mass energy of 7 TeV. The polarisation is measured in bins of transverse momentum [Formula: see text] and rapidity [Formula: see text] in the kinematic region [Formula: see text] and [Formula: see text], and is compared to theoretical models. No significant polarisation is observed.

Measurement of the [Formula: see text] meson lifetime using [Formula: see text] decays

The lifetime of the [Formula: see text] meson is measured using semileptonic decays having a [Formula: see text] meson and a muon in the final state. The data, corresponding to an integrated luminosity of [Formula: see text], are collected by the LHCb detector in [Formula: see text] collisions at a centre-of-mass energy of 8 TeV. The measured lifetime is [Formula: see text]where the first uncertainty is statistical and the second is systematic.

Observation of photon polarization in the b→sγ transition

This Letter presents a study of the flavor-changing neutral current radiative B±→K±π∓π±γ decays performed using data collected in proton-proton collisions with the LHCb detector at 7 and 8 TeV center-of-mass energies. In this sample, corresponding to an integrated luminosity of 3  fb-1, nearly 14 000 signal events are reconstructed and selected, containing all possible intermediate resonances with a K±π∓π± final state in the [1.1,1.9]  GeV/c2 mass range. The distribution of the angle of the photon direction with respect to the plane defined by the final-state hadrons in their rest frame is studied in intervals of K±π∓π± mass and the asymmetry between the number of signal events found on each side of the plane is obtained. The first direct observation of the photon polarization in the b→sγ transition is reported with a significance of 5.2σ.

Search for Majorana neutrinos in B- → π+ μ- μ- decays

A search for heavy Majorana neutrinos produced in the B- → π+ μ- μ- decay mode is performed using 3  fb(-1) of integrated luminosity collected with the LHCb detector in pp collisions at center-of-mass energies of 7 and 8 TeV at the LHC. Neutrinos with masses in the range 250 to 5000 MeV and lifetimes from zero to 1000 ps are probed. In the absence of a signal, upper limits are set on the branching fraction B(B- → π+ μ- μ-) as functions of neutrino mass and lifetime. These limits are on the order of 10(-9) for short neutrino lifetimes of 1 ps or less. Limits are also set on the coupling between the muon and a possible fourth-generation neutrino.

First result from the Alpha Magnetic Spectrometer on the International Space Station: precision measurement of the positron fraction in primary cosmic rays of 0.5-350 GeV

A precision measurement by the Alpha Magnetic Spectrometer on the International Space Station of the positron fraction in primary cosmic rays in the energy range from 0.5 to 350 GeV based on 6.8 × 10(6) positron and electron events is presented. The very accurate data show that the positron fraction is steadily increasing from 10 to ∼ 250  GeV, but, from 20 to 250 GeV, the slope decreases by an order of magnitude. The positron fraction spectrum shows no fine structure, and the positron to electron ratio shows no observable anisotropy. Together, these features show the existence of new physical phenomena.

Search for maximal flavor violating scalars in same-charge lepton pairs in pp collisions at sqrt[s]=1.96 TeV

Models of maximal flavor violation (MxFV) in elementary particle physics may contain at least one new scalar SU(2) doublet field Phi(FV)=(eta(0),eta(+)) that couples the first and third generation quarks (q_(1), q_(3)) via a Lagrangian term L(FV)=xi(13)Phi(FV)q(1)q(3). These models have a distinctive signature of same-charge top-quark pairs and evade flavor-changing limits from meson mixing measurements. Data corresponding to 2 fb(-1) collected by the Collider Dectector at Fermilab II detector in pp[over ] collisions at sqrt[s]=1.96 TeV are analyzed for evidence of the MxFV signature. For a neutral scalar eta(0) with m_(eta;(0))=200 GeV/c(2) and coupling xi(13)=1, approximately 11 signal events are expected over a background of 2.1+/-1.8 events. Three events are observed in the data, consistent with background expectations, and limits are set on the coupling xi(13) for m(eta(0)=180-300 GeV/c(2).

Search for doubly charged Higgs bosons with lepton-flavor-violating decays involving tau leptons

We search for pair production of doubly charged Higgs particles (H+/- +/-) followed by decays into electron-tau (etau) and muon-tau (mutau) pairs using data (350 pb(-1) collected from [over]pp collisions at sqrt[s]=1.96 TeV by the CDF II experiment. We search separately for cases where three or four final-state leptons are detected, and combine results for exclusive decays to left-handed etau (mutau) pairs. We set an H+/- +/- lower mass limit of 114(112) GeV/c(2) at the 95% confidence level.

Search for pair production of scalar top quarks decaying to a tau lepton and a b quark in pp over collisions at sqrt s=1.96 TeV

We search for pair production of supersymmetric top quarks (t over1), followed by R-parity violating decay t over1-->taub with a branching ratio beta, using 322 pb(-1) of pp over collisions at sqrt s=1.96 TeV collected by the upgraded Collider Detector at Fermilab. Two candidate events pass our final selection criteria, consistent with the standard model expectation. We set upper limits on the cross section sigma(t over1t over1) x beta2 as a function of the top-squark mass m(t over1). Assuming beta=1, we set a 95% confidence level limit m(t over1)>153 GeV/c2. The limits are also applicable to the case of a third-generation scalar leptoquark (LQ3) decaying LQ3-->taub.

Search for resonant tt[overline] production in pp[overline] collisions at sqrt[s]=1.96 TeV

We report on a search for narrow-width particles decaying to a top and antitop quark pair. The data set used in the analysis corresponds to an integrated luminosity of 680 pb(-1) collected with the Collider Detector at Fermilab in run II. We present 95% confidence level upper limits on the cross section times branching ratio. Assuming a specific top-color-assisted technicolor production model, the leptophobic Z' with width Gamma(Z')=0.012M(Z'), we exclude the mass range M(Z')<725 GeV/c(2) at the 95% confidence level.

Search for the Higgs boson in events with missing transverse energy and b quark jets produced in pp collisions at square root(s)=1.96 TeV

We search for the standard model Higgs boson produced in association with an electroweak vector boson in events with no identified charged leptons, large imbalance in transverse momentum, and two jets where at least one contains a secondary vertex consistent with the decay of b hadrons. We use approximately 1 fb(-1) integrated luminosity of pp collisions at square root(s)=1.96 TeV recorded by the Collider Detector at Fermilab II experiment at the Tevatron. We find 268 (16) single (double) b-tagged candidate events, where 248+/-43 (14.4+/-2.7) are expected from standard model background processes. We observe no significant excess over the expected background and thus set 95% confidence level upper limits on the Higgs boson production cross section for several Higgs boson masses ranging from 110 to 140 GeV/c(2). For a mass of 115 GeV/c(2), the observed (expected) limit is 20.4 (14.2) times the standard model prediction.

Strong evidence for ZZ production in pp[over] collisions at sqrt[s]=1.96 TeV

We report the first evidence of Z boson pair production at a hadron collider with a significance exceeding 4 standard deviations. This result is based on a data sample corresponding to 1.9 fb(-1) of integrated luminosity from pp[over] collisions at sqrt[s]=1.96 TeV collected with the Collider Detector at Fermilab II detector. In the lll'l' channel, we observe three ZZ candidates with an expected background of 0.096(-0.063)+0.092 events. In the llnunu channel, we use a leading-order calculation of the relative ZZ and WW event probabilities to discriminate between signal and background. In the combination of lll'l' and llnunu channels, we observe an excess of events with a probability of 5.1 x 10(-6) to be due to the expected background. This corresponds to a significance of 4.4 standard deviations. The measured cross section is sigma(pp[over]-->ZZ)=1.4(-0.6)+0.7(stat+syst) pb, consistent with the standard model expectation.

Observation of the decay Bc+/--->J/psipi+/- and measurement of the Bc+/- mass

The Bc+/- meson is observed through the decay Bc+/--->J/psipi+/-, in data corresponding to an integrated luminosity of 2.4 fb(-1) recorded by the Collider Detector at Fermilab II detector at the Fermilab Tevatron. A signal of 108+/-15 candidates is observed, with a significance that exceeds 8sigma. The mass of the Bc+/- meson is measured to be 6275.6+/-2.9(stat)+/-2.5(syst) MeV/c2.

First flavor-tagged determination of bounds on mixing-induced CP violation in Bs0 --> J/psiphi decays

This Letter describes the first determination of bounds on the CP-violation parameter 2beta(s) using B(s)(0) decays in which the flavor of the bottom meson at production is identified. The result is based on approximately 2000 B(s)(0)-->J/psiphi decays reconstructed in a 1.35 fb(-1) data sample collected with the CDF II detector using pp collisions produced at the Fermilab Tevatron. We report confidence regions in the two-dimensional space of 2beta(s) and the decay-width difference DeltaGamma. Assuming the standard model predictions of 2beta(s) and DeltaGamma, the probability of a deviation as large as the level of the observed data is 15%, corresponding to 1.5 Gaussian standard deviations.

Search for heavy toplike quarks using lepton plus jets events in 1.96 TeV pp collisions

We present the results of a search for pair production of a new heavy toplike quark t' decaying to a W boson and another quark using the Collider Detector at Fermilab II detector in run II of the Tevatron pp collider. Using a data sample corresponding to 760 pb(-1) of integrated luminosity, we fit the observed spectrum of total transverse energy and reconstructed t' quark mass to a combination of standard model processes and t' pair production. We see no evidence for t't' production, and we infer a lower limit of 256 GeV/c(2) on the mass of the t' at 95% C.L. assuming standard strong couplings for the t'.

Measurement of Lifetime and Decay-Width Difference in B_{s};{0}-->J/psivarphi Decays

We measure the mean lifetime tau=2/(Gamma_{L}+Gamma_{H}) and the decay-width difference DeltaGamma=Gamma_{L}-Gamma_{H} of the light and heavy mass eigenstates of the B_{s}{0} meson, B_{sL}{0} and B_{sH}{0}, in B_{s}{0}-->J/psivarphi decays using 1.7 fb;{-1} of data collected with the CDF II detector at the Fermilab Tevatron pp[over ] collider. Assuming CP conservation, a good approximation for the B_{s}{0} system in the standard model, we obtain DeltaGamma=0.076_{-0.063}{+0.059}(stat)+/-0.006(syst) ps{-1} and tau=1.52+/-0.04(stat)+/-0.02(syst) ps, the most precise measurements to date. Our constraints on the weak phase and DeltaGamma are consistent with CP conservation.

Evidence for D0-D(0) mixing using the CDF II detector

We measure the time dependence of the ratio of decay rates for the rare decay D{0}-->K{+}pi{-} to the Cabibbo-favored decay D{0}-->K{-}pi;{+}. A signal of 12.7x10;{3} D{0}-->K{+}pi{-} decays was obtained using the Collider Detector at Fermilab II detector at the Fermilab Tevatron with an integrated luminosity of 1.5 fb;{-1}. We measure the D0-D[over ]{0} mixing parameters (R_{D},y{'},x{'2}), and find that the data are inconsistent with the no-mixing hypothesis with a probability equivalent to 3.8 Gaussian standard deviations.

Search for Bs0 --> micro+ micro- and B0 --> micro+ micro- decays with 2 fb-1 of pp collisions

We have performed a search for B(s)(0) --> micro(+) micro(-) and B(0) --> micro(+) micro(-) decays in pp collisions at square root s = 1.96 TeV using 2 fb(-1) of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron Collider. The observed number of B(s)(0) and B0 candidates is consistent with background expectations. The resulting upper limits on the branching fractions are B(B(s)0) --> micro(+) micro(-)) <5.8 x 10(-8) and B(B(0) --> micro(+) micro(-))<1.8 x 10(-8) at 95% C.L.

Measurement of inclusive jet cross sections in Z/gamma*(-->e+e-) + jets production in pp[over ] collisions at square root s = 1.96 TeV

Inclusive jet cross sections in Z/gamma* events, with Z/gamma* decaying into an electron-positron pair, are measured as a function of jet transverse momentum and jet multiplicity in pp[over ] collisions at square root s = 1.96 TeV with the upgraded Collider Detector at Fermilab in run II, based on an integrated luminosity of 1.7 fb(-1). The measurements cover the rapidity region |y(jet)|<2.1 and the transverse momentum range p(T)(jet)>30 GeV/c. Next-to-leading order perturbative QCD predictions are in good agreement with the measured cross sections.

First measurement of W boson production in association with a single Charm quark in pp collisions at sqrt(s)=1.96 TeV

We present the first measurement of the production cross section of a W boson with a single charm quark (c) in pp collisions at sqrt(s)=1.96 TeV, using soft muon tagging of c jets. In a data sample of approximately 1.8 fb(-1), recorded with the Collider Detector at Fermilab II detector at the Fermilab Tevatron, we select events with W+1 or 2 jets. We use the charge correlation between the W and the muon from the semileptonic decay of a charm hadron to extract the Wc signal. We measure sigma Wc(PTc >20 GeV/c,|eta c|<1.5) x BR(W-->l nu)=9.8+/-3.2 pb, in agreement with theoretical expectations.

Observation of orbitally excited B(s) mesons

We report the observation of two narrow resonances consistent with states of orbitally excited (L=1) B_(s) mesons using 1 fb;(-1) of pp[over ] collisions at sqrt[s]=1.96 TeV collected with the Collider Detector at Fermilab II detector at the Fermilab Tevatron. We use two-body decays into K- and B+ mesons reconstructed as B(+)-->J/psiK(+), J/psi-->mu(+)mu(-) or B(+)-->D[over ](0)pi(+), D[over ](0)-->K(+)pi(-). We deduce the masses of the two states to be m(B_(s1))=5829.4+/-0.7 MeV/c(2) and m(B_(s2);(*))=5839.6+/-0.7 MeV/c;(2).

Direct measurement of the W Boson width in ppover collisions at square roots = 1.96 TeV

A direct measurement of the total decay width of the W boson Gamma(W) is presented using 350 pb(-1) of data from pp[over ] collisions at square root s = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. The width is determined by normalizing predicted signal and background distributions to 230 185 W candidates decaying to enu and micronu in the transverse-mass region 50<M(T)<90 GeV and then fitting the predicted shape to 6055 events in the high-M(T) region, 90<M(T)<200 GeV. The result is Gamma(W)=2032 +/- 45(stat)+/-57(syst) MeV, consistent with the standard model expectation.

Cross-section-constrained top-quark mass measurement from dilepton events at the Tevatron

We report the first top-quark mass measurement that uses a cross-section constraint to improve the mass determination. This measurement is made with a dilepton tt event candidate sample collected with the Collider Detector II at Fermilab. From a data sample corresponding to an integrated luminosity of 1.2 fb(-1), we measure a top-quark mass of 170.7(-3.9)(+4.2)(stat)+/-2.6(syst)+/-2.4(theory) GeV/c(2). The measurement without the cross-section constraint is 169.7(-4.9)(+5.2)(stat)+/-3.1(syst) GeV/c(2).

Search for standard model Higgs bosons produced in association with W bosons

We report on the results of a search for standard model Higgs bosons produced in association with W bosons from pp[over] collisions at sqrt[s]=1.96 TeV. The search uses a data sample corresponding to approximately 1 fb(-1) of integrated luminosity. Events consistent with the W-->lnu and H-->bb[over] signature are selected by triggering on a high-p(T) electron or muon candidate and tagging one or two of the jet candidates as having originated from b quarks. A neural network filter rejects a fraction of tagged charm and light-flavor jets, increasing the b-jet purity in the sample. We observe no excess lnubb[over] production beyond the background expectation, and we set 95% confidence level upper limits on the production cross section times branching fraction sigma(pp[over]-->WH)Br(H-->bb[over]) ranging from 3.9 to 1.3 pb, for specific Higgs boson mass hypotheses in the range 110 to 150 GeV/c2, respectively.

First observation of the decay Bs0-->Ds-Ds+ and measurement of its branching ratio

We report the observation of the exclusive decay Bs0-->Ds-Ds+ at the 7.5 standard deviation level using 355 pb(-1) of data collected by the CDF II detector in pp collisions at sqrt[s]=1.96 TeV at the Fermilab Tevatron. We measure the relative branching ratio B(Bs0-->Ds-Ds+)/B(B0-->D-Ds+)=1.44(-0.44)(+0.48). Using the world average value for B(B0-->D-Ds+), we find B(Bs0-->Ds-Ds+)=(9.4(-4.2)(+4.4))x10(-3). This provides a lower bound DeltaGammasCP/Gammas>or=2B(Bs0-->Ds-Ds+)>1.2x10(-2) at 95% C.L.