1,983 research outputs found
Complete study of four top quark production at the LHC in the SMEFT
We present a study of four top quark production at the LHC in the Standard
Model Effective Field Theory (SMEFT). The analysis is performed at the
tree-level, including all terms from the mixed QCD-EW-coupling cross-section
expansion and all the relevant dimension-six SMEFT operators. We find several
cases in which formally subleading terms give rise to significant
contributions. Moreover, we obtain limits on the SMEFT Wilson coefficients
(WCs), including different collider setups, FCC-hh and HL-LHC, using a
simplified chi-square fit. Through the latter, we also assessed the importance
of including differential information in the fit.Comment: 9 pages. Contribution to the 41st International Conference on High
Energy Physics - ICHEP2022. v2: 6 pages, reduced to fit PoS guidelines, v2
accepted by Po
Exploiting exotic LHC datasets for long-lived new particle searches
Motivated by the expectation that new physics may manifest itself in the form
of very heavy new particles, most of the operation time of the LHC is devoted
to collisions at the highest achievable energies and collision rates. The
large collision rates imply tight trigger requirements that include high
thresholds on the final-state particles' transverse momenta and an
intrinsic background in the form of particle pileup produced by different
collisions occurring during the same bunch crossing. This strategy is
potentially sub-optimal for several well-motivated new physics models where new
particles are not particularly heavy and can escape the online selection
criteria of the multi-purpose LHC experiments due to their light mass and small
coupling. A solution may be offered by complementary datasets that are
routinely collected by the LHC experiments. These include heavy ion collisions,
low-pileup runs for precision physics, and the so-called 'parking' and
'scouting' datasets. While some of them are motivated by other physics goals,
they all have the usage of mild thresholds at the trigger-level in
common. In this study, we assess the relative merits of these datasets for a
representative model whose particular clean signature features long-lived
resonances yielding displaced dimuon vertices. We compare the reach across
those datasets for a simple analysis, simulating LHC data in Run 2 and Run 3
conditions with the Delphes simulation. We show that the scouting and parking
datasets, which afford low- trigger thresholds by only using partial
detector information and delaying the event reconstruction, respectively, have
a reach comparable to the standard dataset with conventional thresholds.
We also show that heavy ion and low-pileup datasets are far less competitive
for this signature.Comment: 23 pages with tables and figure
Quality characteristics of chicken burger processed from broiler chicken fed on different types of vegetable oils and feed additives
The objective of this study was to investigate the effect of feeding broiler chicken on different vegetable oils with commercial multi- enzyme feed additives on the quality characteristics of chicken burger. A total of 216 one-day-old chicks of (Hubbard) strain were randomly assigned to six dietary treatments as (2×3) factorial designs where two sources of dietary oil contained soybean oil and palm oil with three levels of commercial multi-enzyme feed additives. Treatments were: soybean oil only (T1), soybean oil+ ZAD (T2), soybean oil+ AmPhi-BACT (T3), palm oil only (T4) , palm oil + ZAD (T5) and palm oil + AmPhi- BACT (T6). Results showed that chicken burger of T1 group had the higher pH value (6.22); slight difference was found in pH value of T3 group (6.18). No significant difference was found in burger of T5 and T6 group. Burger processed from T1 group had the higher T.B.A value (0.115) followed by burger of T5 (0.076); while the lowest T.B.A value found in burger of T2 group (0.031). No significant differences were found in shrinkage measurements. Burger processed from T6 group had the higher score of sensory attributes and overall acceptability, while the differences between the other burger groups were not significant
Complete SMEFT predictions for four top quark production at hadron colliders
We study four top quark production at hadron colliders in the Standard Model
Effective Field Theory (SMEFT). We perform an analysis at the tree-level,
including all possible QCD- and EW-coupling orders and relevant dimension-six
operators. We find several cases where formally subleading terms give rise to
significant contributions, potentially providing sensitivity to a broad class
of operators. Inclusive and differential predictions are presented for the LHC
and a future circular collider operating at TeV. We estimate the
sensitivity of different operators and perform a simplified chi-square fit to
set limits on SMEFT Wilson coefficients. In so doing, we assess the importance
of including subleading terms and differential information in constraining new
physics contributions. Finally, we compute the SMEFT predictions for the double
insertion of dimension-six operators and scrutinise the possible enhancements
to the sensitivity induced by a specific class of higher order terms in the EFT
series.Comment: 32 pages with tables and figures, v2: version accepted by JHE
Single top production in association with a WZ pair at the LHC in the SMEFT
We study single top quark production in association with a WZ pair at the LHC in the context of the Standard Model (SM) and the Standard Model Effective Field Theory (SMEFT). A significant advantage of tWZ compared to other EW top production processes is its sensitivity to unitarity-violating behaviour induced in its 2 → 2 sub-amplitudes through modified EW interactions. At NLO in QCD, tWZ interferes with tt‾ overline{t} tZ and tt‾ overline{t} t and a method to meaningfully separate it from these overlapping processes needs to be employed. In order to define tWZ production for total rates and differential distributions, we consider the approaches proposed in the literature for similar cases and find that diagram-removal procedures provide reliable results both for the SM and the SMEFT in a suitably defined phase-space region. We provide robust results for total and differential cross sections for tWZ at 13 TeV, including the six relevant dimension-6 operators (OtW mathcal{O} _{tW}OtW​,OtZ mathcal{O} _{tZ}OtZ​,OtG mathcal{O} _{tG}OtG​,OφQ(−) {mathcal{O}}_{arphi Q}^{left(-
ight)} OφQ(−)​,OφQ(3) {mathcal{O}}_{arphi Q}^{(3)} OφQ(3)​,Oφt mathcal{O} _{φt}Oφt​), also matching short-distance events to parton shower
Efficiency of two decoders based on hash techniques and syndrome calculation over a Rayleigh channel
The explosive growth of connected devices demands high quality and reliability in data transmission and storage. Error correction codes (ECCs) contribute to this in ways that are not very apparent to the end user, yet indispensable and effective at the most basic level of transmission. This paper presents an investigation of the performance and analysis of two decoders that are based on hash techniques and syndrome calculation over a Rayleigh channel. These decoders under study consist of two main features: a reduced complexity compared to other competitors and good error correction performance over an additive white gaussian noise (AWGN) channel. When applied to decode some linear block codes such as Bose, Ray-Chaudhuri, and Hocquenghem (BCH) and quadratic residue (QR) codes over a Rayleigh channel, the experiment and comparison results of these decoders have shown their efficiency in terms of guaranteed performance measured in bit error rate (BER). For example, the coding gain obtained by syndrome decoding and hash techniques (SDHT) when it is applied to decode BCH (31, 11, 11) equals 34.5 dB, i.e., a reduction rate of 75% compared to the case where the exchange is carried out without coding and decoding process
Fatty acids profile and quality characteristics of broiler chicken meat fed different dietary oil sources with some additives
The study was carried out to investigate the effect of feeding broiler chicken on different vegetable oils with feed additives on the quality characteristics of chicken meat. A total of 216 one-day-old chicks of (Hubbard) strain were randomly assigned to six dietary treatments as (2×3) factorial designs where two sources of dietary oil with three levels of commercial multi-enzyme feed additives. Treatments were: soybean oil only (T1), soybean oil+ ZAD (T2), soybean oil+ AmPhi-BACT (T3), palm oil only (T4), palm oil + ZAD (T5) and palm oil + AmPhi- BACT (T6). Results showed that feeding broiler chicken on different types of dietary oils had significant effect on the fatty acid profile of broiler chicken meat. UFA/SFA ration of broiler chicken groups (T4, T5adT6) were significantly lower compared with (T1, T2 and T3) groups. Broiler fed on soybean oil had significantly higher n-6: n-3 ration compared with broiler fed on palm oil. Regardless of the source of dietary oil, significant differences were observed in the most of fatty acid profile in the chicken meat among levels of commercial multi- enzyme feed additives. Meat of T5and T6 had the higher pH value, followed by meat of T1and T3 groups, while the lowest pH value found in meat of T2 and T4. The higher cooking loss was found in meat of T4 while, meat of T5had the lowest value. Data of chilling loss indicated that the differences between dietary treatments were not significantly different except for meat of T6 which had the higher chilling loss. No significant differences were found in color measurements between dietary treatments
Purification of a chymotrypsin-like enzyme present on adult Schistosoma mansoni worms from infected mice and its characterization as a host carboxylesterase
A serine protease-like enzyme found in detergent extracts of Schistosoma mansoni adult worms perfused from infected mice has been purified from mouse blood and further characterized. The enzyme is approximately 85 kDa and hydrolyses N-acetyl-DL-phenylalanine β-naphthyl–ester, a chromogenic substrate for chymotrypsin-like enzymes. The enzyme from S. mansoni worms appears to be antigenically and enzymatically similar to a molecule that is present in normal mouse blood and so is seemingly host-derived. The enzyme was partially purified by depleting normal mouse serum of albumin using sodium chloride and cold ethanol, followed by repeated rounds of purification by one-dimensional sodium dodecyl sulphate polyacrylamide gel electrophoresis. The purified material was subjected to tandem mass spectrometry and its derived peptides found to belong to mouse carboxylesterase 1C. Its ability to hydrolyse α- or β-naphthyl acetates, which are general esterase substrates, has been confirmed. A similar carboxylesterase was purified and characterized from rat blood. Additional evidence to support identification of the enzyme as a carboxylesterase has been provided. Possible roles of the enzyme in the mouse host–parasite relationship could be to ease the passage of worms through the host's blood vessels and/or in immune evasion
Evaluation of alternative solvents in common amide coupling reactions : replacement of dichloromethane and N,N-dimethylformamide
A range of alternative solvents have been evaluated within amidation reactions employing common coupling reagents with a view to identifying suitable replacements for dichloromethane and N,N-dimethylformamid
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