LHCb trigger streams optimization

The LHCb experiment stores around $10^{11}$ collision events per year. A typical physics analysis deals with a final sample of up to $10^7$ events. Event preselection algorithms (lines) are used for data reduction. Since the data are stored in a format that requires sequential access, the lines are grouped into several output file streams, in order to increase the efficiency of user analysis jobs that read these data. The scheme efficiency heavily depends on the stream composition. By putting similar lines together and balancing the stream sizes it is possible to reduce the overhead. We present a method for finding an optimal stream composition. The method is applied to a part of the LHCb data (Turbo stream) on the stage where it is prepared for user physics analysis. This results in an expected improvement of 15% in the speed of user analysis jobs, and will be applied on data to be recorded in 2017.Comment: Submitted to CHEP-2016 proceeding

Deep learning for inferring cause of data anomalies

Daily operation of a large-scale experiment is a resource consuming task, particularly from perspectives of routine data quality monitoring. Typically, data comes from different sub-detectors and the global quality of data depends on the combinatorial performance of each of them. In this paper, the problem of identifying channels in which anomalies occurred is considered. We introduce a generic deep learning model and prove that, under reasonable assumptions, the model learns to identify 'channels' which are affected by an anomaly. Such model could be used for data quality manager cross-check and assistance and identifying good channels in anomalous data samples. The main novelty of the method is that the model does not require ground truth labels for each channel, only global flag is used. This effectively distinguishes the model from classical classification methods. Being applied to CMS data collected in the year 2010, this approach proves its ability to decompose anomaly by separate channels.Comment: Presented at ACAT 2017 conference, Seattle, US

Red flags to diagnose infiltrative cardiomyopathies

Infiltrative cardiomyopathies are a group of diseases characterized by the deposition of abnormal substances in heart tissues, which leads to thickening of the walls or dilation of chambers with a secondary decrease in wall thickness and the development of diastolic, less often systolic, ventricular dysfunction. Most often, these are progressive diseases that, in the absence of adequate therapy, have an unfavorable prognosis. Clinical manifestations of infiltrative cardiac diseases are variable, which often leads to diagnostic difficulties and errors. In most cases, specific laboratory and morphological tests are required to confirm or clarify the diagnosis. Early diagnosis is critical to initiating therapy and improving patient prognosis. This article provides characteristic signs and symptoms, the so-called "red flags", making it possible to suspect infiltrative cardiomyopathies, diagnose them at an early stage and start life-saving therapy

A facility to Search for Hidden Particles (SHiP) at the CERN SPS

A new general purpose fixed target facility is proposed at the CERN SPS accelerator which is aimed at exploring the domain of hidden particles and make measurements with tau neutrinos. Hidden particles are predicted by a large number of models beyond the Standard Model. The high intensity of the SPS 400~GeV beam allows probing a wide variety of models containing light long-lived exotic particles with masses below ${\cal O}$(10)~GeV/c$^2$, including very weakly interacting low-energy SUSY states. The experimental programme of the proposed facility is capable of being extended in the future, e.g. to include direct searches for Dark Matter and Lepton Flavour Violation.Comment: Technical Proposa

Measurement of the CKM angle γ from a combination of B±→Dh± analyses

A combination of three LHCb measurements of the CKM angle γ is presented. The decays B±→D K± and B±→Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K+K−, π+π−, K±π∓, K±π∓π±π∓, K0Sπ+π−, or K0S K+K− final states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B±→D K± decays alone a best-fit value of γ =72.0◦ is found, and confidence intervals are set γ ∈ [56.4,86.7]◦ at 68% CL, γ ∈ [42.6,99.6]◦ at 95% CL. The best-fit value of γ found from a combination of results from B±→Dπ± decays alone, is γ =18.9◦, and the confidence intervals γ ∈ [7.4,99.2]◦ ∪ [167.9,176.4]◦ at 68% CL are set, without constraint at 95% CL. The combination of results from B± → D K± and B± → Dπ± decays gives a best-fit value of γ =72.6◦ and the confidence intervals γ ∈ [55.4,82.3]◦ at 68% CL, γ ∈ [40.2,92.7]◦ at 95% CL are set. All values are expressed modulo 180◦, and are obtained taking into account the effect of D0–D0 mixing

Study of DJ meson decays to D+π−, D0π+ and D∗+π− final states in pp collisions

A study of D+π−, D0π+ and D∗+π− final states is performed using pp collision data, corresponding to an integrated luminosity of 1.0 fb−1, collected at a centre-of-mass energy of 7 TeV with the LHCb detector. The D1(2420)0 resonance is observed in the D∗+π− final state and the D∗2(2460) resonance is observed in the D+π−, D0π+ and D∗+π− final states. For both resonances, their properties and spin-parity assignments are obtained. In addition, two natural parity and two unnatural parity resonances are observed in the mass region between 2500 and 2800 MeV. Further structures in the region around 3000 MeV are observed in all the D∗+π−, D+π− and D0π+ final states

ОПРЕДЕЛЕНИЕ СОДЕРЖАНИЯ ЖИРА В ПЕЧЕНИ У ПАЦИЕНТОВ С ЖИРОВЫМ ГЕПАТОЗОМ И СТЕАТОГЕПАТИТОМ МЕТОДОМ ПРОТОННОЙ МР-СПЕКТРОСКОПИИ

Aim. Evaluation of proton MR spectroscopy in the diagnostics of non-alcoholic fatty liver disease.Materials and methods. 70 patients (40 men, 30 women) with non-alcoholic fatty liver disease were included in the study. Average age of patients was 42 ± 11 years. All patients were divided in two groups. The first group included patients with liver steаthosis (n = 37). Patients with steatohepatitis detected by clinical data formed the second group (n = 33). All patients underwent MR spectroscopy for liver fat content evaluation in two time points (prescreening and after 6 months treatment).Results. MR spectroscopy showed fat content in patients with liver steatosis in the range from 7.5% to 58.4%, the median was 22.4% (lower and upper quartiles were 14.9% and 28.7%). After 6 months the liver fat content significantly decreased up to 1.5–43.7%, the median was 13.5% (the lower and upper quartiles were 5.54% and 18.9%). In patients with steatohepatitis the fat content calculated by MR spectroscopy ranged from 10.5% to 60%, the median was 28.8% (the lower and upper quartiles were 16.5% and 31.2%). There was no significant difference in fat content in this group after 6 months therapy (the median was 26.7%, the lower and upper quartiles were 14.2% and 28.7%, p = 0.22).Conclusion. Proton MR spectroscopy can be successfully used in patients with non-alcoholic fatty liver disease for liver fat content quantification in steatosis and steatohepatitis. MR spectroscopy can be discussed as a non-invasive biopsy alternative for dynamic evaluation during treatment.Цель исследования: определение возможности использования протонной МР-спектроскопии в диагностике неалкогольной жировой болезни печени(НАЖБП).Материал и методы. В исследование было включено 70 пациентов (40 мужчин, 30 женщин) с НАЖБП, средний возраст которых составил 42 ± 11 лет. Пациенты были разделены на 2 группы. 1-я группа включала больных со стеатозом печени (37 человек). Во 2-ю группу отбирались пациенты со стеатогепатитом, выявленным по данным клинических исследований (33 пациента). Всем пациентам выполнялась МР-спектроскопия для определения содержания жира в печени в двух точках: перед включением в исследование и спустя 6 мес на фоне лечения.Результаты. В 1-й группе пациентов со стеатозом печени содержание жира по данным МР-спектроскопии находилось в пределах от 7,5 до 58,4%, медиана составила 22,4%, нижняя и верхняя квартили – 14,9 и 28,7%. При регистрации спектров спустя 6 мес концентрация жира в печени значимо снизилась, составляла от 1,5 до 43,7%, медиана – 13,5%, нижняя и верхняя квартили – 5,54 и 18,9% (р = 0,015). Во 2-й группе пациентов со стеатогепатитом содержание жира по результатам МР-спектроскопии составило от 10,5 до 60%, медиана – 28,8%, нижняя и верхняя квартили – 16,5 и 31,2%. При повторном обследовании через 6 мес лечения содержание жира в печени у пациентов со стеатогепатитом достоверно не изменилось: медиана 26,7%, нижняя и верхняя квартили 14,2 и 28,7%(р = 0,22).Заключение. Протонная МР-спектроскопия может успешно применяться у пациентов с НАЖБП для количественной оценки содержания жира в печени при стеатозе и стеатогепатите. Благодаря своей неинвазивности МР-спектроскопия может рассматриваться как альтернатива биопсии при необходимости повторных исследований для оценки динамики изменений на фоне лечения

Study of B0(s)→K0Sh+h′− decays with first observation of B0s→K0SK±π∓ and B0s→K0Sπ+π−

A search for charmless three-body decays of B 0 and B0s mesons with a K0S meson in the final state is performed using the pp collision data, corresponding to an integrated luminosity of 1.0 fb−1, collected at a centre-of-mass energy of 7 TeV recorded by the LHCb experiment. Branching fractions of the B0(s)→K0Sh+h′− decay modes (h (′) = π, K), relative to the well measured B0→K0Sπ+π− decay, are obtained. First observation of the decay modes B0s→K0SK±π∓ and B0s→K0Sπ+π− and confirmation of the decay B0→K0SK±π∓ are reported. The following relative branching fraction measurements or limits are obtained B(B0→K0SK±π∓)B(B0→K0Sπ+π−)=0.128±0.017(stat.)±0.009(syst.), B(B0→K0SK+K−)B(B0→K0Sπ+π−)=0.385±0.031(stat.)±0.023(syst.), B(B0s→K0Sπ+π−)B(B0→K0Sπ+π−)=0.29±0.06(stat.)±0.03(syst.)±0.02(fs/fd), B(B0s→K0SK±π∓)B(B0→K0Sπ+π−)=1.48±0.12(stat.)±0.08(syst.)±0.12(fs/fd)B(B0s→K0SK+K−)B(B0→K0Sπ+π−)∈[0.004;0.068]at90%CL

Observation of the decay Bc→J/ψK+K−π+B_c \rightarrow J/\psi K^+ K^- \pi^+

The decay $B_c\rightarrow J/\psi K^+ K^- \pi^+$ is observed for the first time, using proton-proton collisions collected with the LHCb detector corresponding to an integrated luminosity of 3fb$^{-1}$. A signal yield of $78\pm14$ decays is reported with a significance of 6.2 standard deviations. The ratio of the branching fraction of \B_c \rightarrow J/\psi K^+ K^- \pi^+ decays to that of $B_c \rightarrow J/\psi \pi^+$ decays is measured to be $0.53\pm 0.10\pm0.05$, where the first uncertainty is statistical and the second is systematic.Comment: 18 pages, 2 figure