Effect of different brine concentrations and ripening period on some quality properties of Turkish white pickled cheese

The aim of this study was to determine the effects of different brine concentrations on some properties of Turkish white cheese. Cheeses made from pasteurized milk (65°C for 30 min) were ripened in 11, 14 and 17 g 100 ml-1 NaCl for 90 days at 7±1°C. Some physicochemical and biochemical analyses were carried out during storage time. The effects of brine concentrations on total solids, protein, ash, salt, pH, and WSN values were found to be significant (P<0.05). On the contrary, fat, lipolysis, TCA-SN and PTA-SN values of the cheese samples were not significantly affected by the brine concentrations used. On the other hand, the values of protein, ash, salt, pH, lipolysis, WSN, TCA-SN and PTA-SN of the experimental cheeses were significantly (P<0.05, P<0.01) affected by storage time, while the effect of storage period on total solids and fat contents was found to be insignificant (P>0.05).Key words: Turkish white cheese, brine salting, ripening, lipolysis, proteolysis

Comparison of quality characteristics of Çökelek and Lor cheeses

The objective of this study was to compare some quality characteristics of Çökelek (cottage cheeselike) and Lor (whey cheese) cheeses during a storage period of 21 days. Çökelek and Lor cheeses significantly (P < 0.05, P < 0.01) showed differences in terms of the examined parameters and storage period. Mean value of lipolysis in Çökelek cheese was higher (P < 0.01) than that of Lor cheese. Also storage time affected (P < 0.01) the values of lipolysis in two experiments. It was found that αs1casein was hydrolyzed much faster than those of γ-casein and β-casein in the Çökelek and Lor cheeses, the γ-, β-, and αs1casein levels in two cheeses remained relatively constant during storage. There were no significant differences in water-soluble N (WSN), trichloroacetic acid soluble N (TCA-SN) and phosphotungstic acid soluble N (PTA-SN) contents of the two experiments, but the storage time significantly (P < 0.01) affected these parameters. The counts of coliforms, lactic acid, proteolytic, psycrotrophic bacteria and yeasts-molds between Çökelek and Lor cheese samples were found to be significant (P < 0.01), but total aerobic mesophilic bacteria (TAMB) and Salmonella thermophilus counts were not significant statistically. Storage time significantly (P < 0.01) affected the examined microbiological parameters. Sensory evaluations of the experimental cheeses showed differences in terms of cheese types and storage period.Key words: Çökelek, Lor, lipolysis , proteolysis, microbiology, sensory

Measurement of the t t-bar production cross section in the dilepton channel in pp collisions at sqrt(s) = 7 TeV

The t t-bar production cross section (sigma[t t-bar]) is measured in proton-proton collisions at sqrt(s) = 7 TeV in data collected by the CMS experiment, corresponding to an integrated luminosity of 2.3 inverse femtobarns. The measurement is performed in events with two leptons (electrons or muons) in the final state, at least two jets identified as jets originating from b quarks, and the presence of an imbalance in transverse momentum. The measured value of sigma[t t-bar] for a top-quark mass of 172.5 GeV is 161.9 +/- 2.5 (stat.) +5.1/-5.0 (syst.) +/- 3.6(lumi.) pb, consistent with the prediction of the standard model.Comment: Replaced with published version. Included journal reference and DO

Combined search for the quarks of a sequential fourth generation

Results are presented from a search for a fourth generation of quarks produced singly or in pairs in a data set corresponding to an integrated luminosity of 5 inverse femtobarns recorded by the CMS experiment at the LHC in 2011. A novel strategy has been developed for a combined search for quarks of the up and down type in decay channels with at least one isolated muon or electron. Limits on the mass of the fourth-generation quarks and the relevant Cabibbo-Kobayashi-Maskawa matrix elements are derived in the context of a simple extension of the standard model with a sequential fourth generation of fermions. The existence of mass-degenerate fourth-generation quarks with masses below 685 GeV is excluded at 95% confidence level for minimal off-diagonal mixing between the third- and the fourth-generation quarks. With a mass difference of 25 GeV between the quark masses, the obtained limit on the masses of the fourth-generation quarks shifts by about +/- 20 GeV. These results significantly reduce the allowed parameter space for a fourth generation of fermions.Comment: Replaced with published version. Added journal reference and DO

Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV

A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7 TeV is presented. The data were collected at the LHC, with the CMS detector, and correspond to an integrated luminosity of 4.6 inverse femtobarns. No significant excess is observed above the background expectation, and upper limits are set on the Higgs boson production cross section. The presence of the standard model Higgs boson with a mass in the 270-440 GeV range is excluded at 95% confidence level.Comment: Submitted to JHE

Search for anomalous t t-bar production in the highly-boosted all-hadronic final state

A search is presented for a massive particle, generically referred to as a Z', decaying into a t t-bar pair. The search focuses on Z' resonances that are sufficiently massive to produce highly Lorentz-boosted top quarks, which yield collimated decay products that are partially or fully merged into single jets. The analysis uses new methods to analyze jet substructure, providing suppression of the non-top multijet backgrounds. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 7 TeV, corresponding to an integrated luminosity of 5 inverse femtobarns. Upper limits in the range of 1 pb are set on the product of the production cross section and branching fraction for a topcolor Z' modeled for several widths, as well as for a Randall--Sundrum Kaluza--Klein gluon. In addition, the results constrain any enhancement in t t-bar production beyond expectations of the standard model for t t-bar invariant masses larger than 1 TeV.Comment: Submitted to the Journal of High Energy Physics; this version includes a minor typo correction that will be submitted as an erratu

Measurement of the Z/gamma* + b-jet cross section in pp collisions at 7 TeV

The production of b jets in association with a Z/gamma* boson is studied using proton-proton collisions delivered by the LHC at a centre-of-mass energy of 7 TeV and recorded by the CMS detector. The inclusive cross section for Z/gamma* + b-jet production is measured in a sample corresponding to an integrated luminosity of 2.2 inverse femtobarns. The Z/gamma* + b-jet cross section with Z/gamma* to ll (where ll = ee or mu mu) for events with the invariant mass 60 < M(ll) < 120 GeV, at least one b jet at the hadron level with pT > 25 GeV and abs(eta) < 2.1, and a separation between the leptons and the jets of Delta R > 0.5 is found to be 5.84 +/- 0.08 (stat.) +/- 0.72 (syst.) +(0.25)/-(0.55) (theory) pb. The kinematic properties of the events are also studied and found to be in agreement with the predictions made by the MadGraph event generator with the parton shower and the hadronisation performed by PYTHIA.Comment: Submitted to the Journal of High Energy Physic

Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 inverse femtobarns produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.Comment: Published in Physical Review Letter