1,326 research outputs found
Search for Zc(3900) ± → ωπ ±
No full textÇetin, Serkant Ali (Dogus Author)The decay Zc(3900)±→ωπ± is searched for using data samples collected with the BESIII detector operating at the BEPCII storage ring at center-of-mass energies s=4.23 and 4.26 GeV. No significant signal for the Zc(3900)± is found, and upper limits at the 90% confidence level on the Born cross section for the process e+e-→Zc(3900)±π →ωπ+π- are determined to be 0.26 and 0.18 pb at s=4.23 and 4.26 GeV, respectively
System för detektering av drönare baserat på ZC-sekvensen
No full textThe Unmanned Aerial Vehicle (UAV) industry has experienced rapid growth in recent years. UAV, also known as a drone, is used for a range of applications, including aerial photography and videography, delivery of packages and medical supplies. On the other hand, drones pose a threat to physical safety, as well as the privacy of individuals and organizations, which increases the demand for solutions of drone detection and monitoring. Zadoff-chu (ZC) sequence can be the key feature for detecting drones because most commercial drones apply the ZC sequence as the synchronization sequence. However, blindly detecting the ZC sequence presents a significant challenge since the transmit frequency is unknown to the receiver. Existing studies on detecting the ZC sequence under different frequency offsets are primarily based on Long Term Evolution scenarios. However, the construction and length of the ZC sequence used in drones are different, resulting in varying outcomes. In this paper, we study the auto-correlation property of the specific ZC sequence applied by drones under different center frequency offsets, and we propose a blind drone detection and identification algorithm capable of detecting and identifying multiple drones that employ ZC sequences in their video transmission protocols. In low Signal-to-Noise (SNR) environments, even with a minimum SNR as low as -12 dB, this algorithm can still achieve a detection rate of over 99%.Industrin för obemannade flygfarkoster (UAV) har upplevt en snabb tillväxt de senaste åren. UAV, även känd som drönare, används för en rad tillämpningar, inklusive flygfotografering och videografi, leverans av paket och medicinska förnödenheter. Å andra sidan utgör drönare ett hot mot fysisk säkerhet samt individers och organisationers integritet, vilket ökar efterfrågan på lösningar för drönardetektering och övervakning. Zadoff-Chu (ZC)-sekvensen kan vara en nyckelfunktion för att upptäcka drönare eftersom de flesta kommersiella drönare använder ZC-sekvensen som synkroniseringssekvens. Att blint upptäcka ZC-sekvensen innebär dock en betydande utmaning eftersom sändningsfrekvensen är okänd för mottagaren. Befintliga studier om att upptäcka ZC-sekvensen under olika frekvensförskjutningar är främst baserade på Long Term Evolution-scenarier. Konstruktionen och längden på ZC-sekvensen som används i drönare är dock olika, vilket resulterar i varierande resultat. I denna artikel studerar vi autokorrelations-egenskapen hos den specifika ZC-sekvensen som tillämpas av drönare under olika centerfrekvensförskjutningar, och vi föreslår en blind drönardetekterings- och identifieringsalgoritm som kan upptäcka och identifiera flera drönare som använder ZC-sekvenser i sina videotransmissionsprotokoll. I miljöer med låg signal-brus-förhållande (SNR), även med ett minimum SNR så lågt som -12 dB, kan denna algoritm fortfarande uppnå en detektionsfrekvens på över 99%
System för detektering av drönare baserat på ZC-sekvensen
No full textThe Unmanned Aerial Vehicle (UAV) industry has experienced rapid growth in recent years. UAV, also known as a drone, is used for a range of applications, including aerial photography and videography, delivery of packages and medical supplies. On the other hand, drones pose a threat to physical safety, as well as the privacy of individuals and organizations, which increases the demand for solutions of drone detection and monitoring. Zadoff-chu (ZC) sequence can be the key feature for detecting drones because most commercial drones apply the ZC sequence as the synchronization sequence. However, blindly detecting the ZC sequence presents a significant challenge since the transmit frequency is unknown to the receiver. Existing studies on detecting the ZC sequence under different frequency offsets are primarily based on Long Term Evolution scenarios. However, the construction and length of the ZC sequence used in drones are different, resulting in varying outcomes. In this paper, we study the auto-correlation property of the specific ZC sequence applied by drones under different center frequency offsets, and we propose a blind drone detection and identification algorithm capable of detecting and identifying multiple drones that employ ZC sequences in their video transmission protocols. In low Signal-to-Noise (SNR) environments, even with a minimum SNR as low as -12 dB, this algorithm can still achieve a detection rate of over 99%.Industrin för obemannade flygfarkoster (UAV) har upplevt en snabb tillväxt de senaste åren. UAV, även känd som drönare, används för en rad tillämpningar, inklusive flygfotografering och videografi, leverans av paket och medicinska förnödenheter. Å andra sidan utgör drönare ett hot mot fysisk säkerhet samt individers och organisationers integritet, vilket ökar efterfrågan på lösningar för drönardetektering och övervakning. Zadoff-Chu (ZC)-sekvensen kan vara en nyckelfunktion för att upptäcka drönare eftersom de flesta kommersiella drönare använder ZC-sekvensen som synkroniseringssekvens. Att blint upptäcka ZC-sekvensen innebär dock en betydande utmaning eftersom sändningsfrekvensen är okänd för mottagaren. Befintliga studier om att upptäcka ZC-sekvensen under olika frekvensförskjutningar är främst baserade på Long Term Evolution-scenarier. Konstruktionen och längden på ZC-sekvensen som används i drönare är dock olika, vilket resulterar i varierande resultat. I denna artikel studerar vi autokorrelations-egenskapen hos den specifika ZC-sekvensen som tillämpas av drönare under olika centerfrekvensförskjutningar, och vi föreslår en blind drönardetekterings- och identifieringsalgoritm som kan upptäcka och identifiera flera drönare som använder ZC-sekvenser i sina videotransmissionsprotokoll. I miljöer med låg signal-brus-förhållande (SNR), även med ett minimum SNR så lågt som -12 dB, kan denna algoritm fortfarande uppnå en detektionsfrekvens på över 99%
Observation of Zc (3900)0 in e+e- →π0π0J/ψ
No full textÇetin, Serkant Ali (Dogus Author)Using a data sample collected with the BESIII detector operating at the BEPCII storage ring, we observe a new neutral state Zc(3900)0 with a significance of 10.4σ. The mass and width are measured to be 3894.8±2.3±3.2MeV/c2 and 29.6±8.2±8.2MeV, respectively, where the first error is statistical and the second systematic. The Born cross section for e+e-→π0π0J/ψ and the fraction of it attributable to π0Zc(3900)0→π0π0J/ψ in the range Ec.m.=4.19-4.42GeV are also determined. We interpret this state as the neutral partner of the four-quark candidate Zc(3900)±
Probing the nature of Zc(′) states via the ηcρ decay
No full textAbstractThe nature of the so-called XYZ states is a long-standing problem. It has been suggested that such particles may be described as compact four-quark states or loosely bound meson molecules. In the present work we analyze the Zc(′)→ηcρ decay using both approaches. Such channel might provide useful insights on the nature of the Zc(′), helping discriminating between the two different models
Probing the nature of Zc(') states via the ηc ρ decay
No full textThe nature of the so-called XYZ states is a long-standing problem. It has been suggested that such particles may be described as compact four-quark states or loosely bound meson molecules. In the present work we analyze the Zc(′)→ηcρ decay using both approaches. Such channel might provide useful insights on the nature of the Zc(′) , helping discriminating between the two different models
Confirmation of a charged charmoniumlike state Zc (3885)∓ in e+e- →π± (D D ¯ ∗)∓ with double D tag
No full textÇetin, Serkant Ali (Dogus Author)We present a study of the process e+e-→π±(DD¯∗)∓ using data samples of 1092 pb-1 at s=4.23 GeV and 826 pb-1 at s=4.26 GeV collected with the BESIII detector at the BEPCII storage ring. With full reconstruction of the D meson pair and the bachelor π± in the final state, we confirm the existence of the charged structure Zc(3885)∓ in the (DD¯∗)∓ system in the two isospin processes e+e-→π+D0D∗- and e+e-→π+D-D∗0. By performing a simultaneous fit, the statistical significance of Zc(3885)∓ signal is determined to be greater than 10σ, and its pole mass and width are measured to be Mpole=(3881.7±1.6(stat)±1.6(syst)) MeV/c2 and Γpole=(26.6±2.0(stat)±2.1(syst)) MeV, respectively. The Born cross section times the (DD¯∗)∓ branching fraction (σ(e+e-→π±Zc(3885)∓)×Br(Zc(3885)∓→(DD¯∗)∓)) is measured to be (141.6±7.9(stat)±12.3(syst)) pb at s=4.23 GeV and (108.4±6.9(stat)±8.8(syst)) pb at s=4.26 GeV. The polar angular distribution of the π±-Zc(3885)∓ system is consistent with the expectation of a quantum number assignment of JP=1+ for Zc(3885)∓
Observation of a neutral charmoniumlike state Zc (4025)0 in e+e- → (D∗ D ¯ ∗)0π0
No full textÇetin, Serkant Ali (Dogus Author)We report a study of the process e+e-→(D∗D¯∗)0π0 using e+e- collision data samples with integrated luminosities of 1092 pb-1 at s=4.23 GeV and 826 pb-1 at s=4.26 GeV collected with the BESIII detector at the BEPCII storage ring. We observe a new neutral structure near the (D∗D¯∗)0 mass threshold in the π0 recoil mass spectrum, which we denote as Zc(4025)0. Assuming a Breit-Wigner line shape, its pole mass and pole width are determined to be (4025.5-4.7+2.0±3.1) MeV/c2 and (23.0±6.0±1.0) MeV, respectively. The Born cross sections of e+e-→Zc(4025)0π0→(D∗D¯∗)0π0 are measured to be (61.6±8.2±9.0) pb at s=4.23 GeV and (43.4±8.0±5.4) pb at s=4.26 GeV. The first uncertainties are statistical and the second are systematic
Study of e+e- →π+π-π0ηc and evidence for Zc (3900)± decaying into ρ±ηc STUDY of e+e- →π+π-π0ηc ... M. ABLIKIM et al
No full textWe study the reaction e+e-→π+π-π0ηc for the first time using data samples collected with the BESIII detector at center-of-mass energies s=4.226, 4.258, 4.358, 4.416, and 4.600 GeV. Evidence of this process is found and the Born cross section σB(e+e-→π+π-π0ηc), excluding e+e-→ωηc and ηηc, is measured to be (46-11+12±10) pb at s=4.226 GeV. Evidence for the decay Zc(3900)±→ρ±ηc is reported at s=4.226 GeV with a significance of 3.9σ, including systematic uncertainties, and the Born cross section times branching fraction σB(e+e-→π Zc(3900)±)×B(Zc(3900)±→ρ±ηc) is measured to be (48±11±11) pb, which indicates that e+e-→π Zc(3900)±→πρ±ηc dominates the e+e-→π+π-π0ηc process. The Zc(3900)±→ρ±ηc signal is not significant at the other center-of-mass energies and the corresponding upper limits are determined. In addition, no significant signal is observed in a search for Zc(4020)±→ρ±ηc with the same data samples. The ratios RZc(3900)=B(Zc(3900)±→ρ±ηc)/B(Zc(3900)±→π±J/ψ) and RZc(4020)=B(Zc(4020)±→ρ±ηc)/B(Zc(4020)±→π±hc) are obtained and compared with different theoretical interpretations of the Zc(3900)± and Zc(4020)±
The Zc(3900) peak does not come from the “triangle singularity”
No full textAbstract We compare contributions from the triangle diagram and the DD¯∗ bubble chain with the processes of e+e-→J/ψπ+π- and e+e-→(DD¯∗)∓π± . By fitting the J/ψπ maximum spectrum and the DD¯∗ spectrum, we find that the triangle diagram cannot explain the new experimental results from BESIII Collaboration at center of mass at 4.23 and 4.26 GeV, simultaneously. On the contrary, the molecular assignment of Zc(3900) gives a much better description
- …
